Islet cell transplantation todaydcl3/Ref_2007-Aug-17/islet...Results Data analysis of islet cell transplants performed in the last 5 years (1999–2004) shows at 1 year after adult

CURRENT CONCEPTS IN CLINICAL SURGERY

Islet cell transplantation today

Reinhard G. Bretzel & Henning Jahr &

Michael Eckhard & Isabel Martin &

Daniel Winter & Mathias D. Brendel

Received: 15 February 2007 /Accepted: 15 February 2007 / Published online: 28 March 2007# Springer-Verlag 2007

AbstractIntroduction Long-term studies strongly suggest that tightcontrol of blood glucose can prevent the development andretard the progression of chronic complications of type 1diabetes mellitus. In contrast to conventional insulin treat-ment, replacement of a patient’s islets of Langerhans either bypancreas organ transplantation or by isolated islet transplan-tation is the only treatment to achieve a constant normogly-cemic state and avoiding hypoglycemic episodes, a typicaladverse event of multiple daily insulin injections. However,the cost of this benefit is still the need for immunosuppressivetreatment of the recipient with all its potential risks.Materials and methods Islet cell transplantation offers theadvantage of being performed as a minimally invasiveprocedure in which islets can be perfused percutaneously intothe liver via the portal vein. Between January 1990 andDecember 2004, 458 pancreatic islet transplants worldwidehave been reported to the International Islet TransplantRegistry (ITR) at our Third Medical Department, Universityof Giessen/Germany.Results Data analysis of islet cell transplants performed inthe last 5 years (1999–2004) shows at 1 year after adult islettransplantation a patient survival rate of 97%, a functioningislet graft in 82% of the cases, whereas insulin independencewas meanwhile achieved in 43% of the cases. However,using a novel protocol established by the Edmonton Center/Canada, the insulin independence rates have improvedsignificantly reaching meanwhile a 50–80% level.

Conclusion Finally, the concept of islet cell or stem celltransplantation is most attractive, as it offers manyperspectives: islet cell availability could become unlimitedand islet or stem cells my be transplanted without life-longimmunosuppressive treatment of the recipient, just tomention two of them.

Keywords Diabetes mellitus . Islet cell transplantation .

Tolerance induction . Xenotransplants . Stem cell therapy

Introduction

Type 1 diabetes mellitus is a chronic metabolic disorder thatcurrently afflicts approximately 5 million individuals in theworld and about 300,000 subjects in Germany (Fig. 1). Itresults from autoimmune-mediated destruction of insulin-secreting beta-cells in the islets of Langerhans of thepancreas [1, 2]. Thousands of new cases with severe diabeticcomplications are registered every year (Fig. 2). Long-termstudies strongly suggest that tight control of blood glucoseachieved by conventional or intensive insulin treatment, selfblood glucose monitoring, and patient education cansignificantly prevent the development and retard the pro-gression of chronic complications of this disease [3–5].However, the cost of this benefit was a threefold increase inthe number of severe hypoglycemic episodes, a significantincrease of body weight, and dietary and other lifestylerestrictions affecting the quality of life [6].

By contrast, replacement of a patient’s islets ofLangerhans either by pancreas transplantation or by isolatedislet transplantation is the only treatment of type 1 diabetesmellitus that achieves an insulin-independent, constantnormoglycemic state, and avoidance of hypoglycemicepisodes [7, 8]. The cost of this benefit, however, is the

Langenbecks Arch Surg (2007) 392:239–253DOI 10.1007/s00423-007-0183-4

R. G. Bretzel (*) :H. Jahr :M. Eckhard :I. Martin :D. Winter :M. D. BrendelThird Medical Department and Policlinic,University Hospital Giessen and Marburg GmbH,Rodthohl 6,35392 Giessen, Germanye-mail: [email protected]

need for immunosuppressive treatment of the recipient withall its potential risks.

At present, vascularized whole-pancreas organ transplan-tation reliably restores normoglycemia and maintains long-term glucose homeostasis. Approximately 25,000 patientsworldwide underwent this procedure and it has been shown toimprove quality of life and even reverse some secondarycomplications of diabetes [9–11]. Simultaneous pancreas andkidney transplantation are presently considered the standardof care for selected patients with type 1 diabetes with end-stage renal failure [11]. Results in this group are approachingthose of other solid organs, with pancreas function rates after1 year of greater than 85% of patients, which means totalinsulin-independence in these previously diabetic recipients[9]. However, despite significant progress, pancreas trans-plantation is still associated with perioperative mortality andsignificant morbidity [12–14].

In contrast, islet cell transplantation offers the advantage ofbeing performed as a minimally invasive procedure, in whichislets can be perfused percutaneously into the liver via theportal vein in local anesthesia [15]. Since about threedecades, islet cell transplantation has been proposed for thescientific community and promised to patients and theirfamilies. However, the most convincing results in smallanimal studies did not as successfully translate to the clinicalsetting. Nonetheless, a few early case reports of insulinindependence achieved by intraportal islet allotransplants intype 1 diabetic recipients do exist, including the first case ofinsulin independence reported by Paul Lacy’s group in St.Louis (Fig. 3) [8, 16–20]. However, overall clinical resultswere unacceptably poor, with 1-year insulin independencerates as low as 8% (ITR Newsletter) (Fig. 4).

The introduction of an automated method has permittedretrieval of a sufficient number of islets even from a singlehuman donor pancreas to allow reversal of diabetes afterallotransplantation in a type 1 diabetic patient and has madeinsulin independence more likely [21]. With this methodavailable, a new era of clinical islet transplantation, eithersimultaneous with (SIK) or after kidney transplantation(IAK) started in the early 1990s. Introducing a new protocolwith improved peri-transplant management and immuno-

suppression we reported our first insulin-independent islet-after-kidney recipient after a single-donor islet transplanta-tion (Fig. 5) [8]. The decade closed on an optimistic notewith a series of islet-kidney transplants completed inGiessen, Germany, demonstrating that 26% of their casesmaintained insulin independence beyond 1 year usingsingle-donor islet preparations (Fig. 4) [22, 23].

It was, however, only after the Edmonton Group’s reportof an 80% insulin independence rate (Fig. 4) that islettransplantation appeared as a true alternative to conserva-tive medical management using intensified insulin treat-ment or to whole-pancreas organ transplantation [24]. Thisreport stimulated several medical centers worldwide torejuvenate or establish islet transplant facilities. Meanwhile,islet allotransplants have been performed in 1,049 patientswith type 1 diabetes mellitus in the era between January1990 and December 2005 (ITR Giessen). However, thereare only 11 institutions worldwide, four in North Americaand seven in Europe, to have performed more than 20 casesper center and which have transplanted together more thanhalf of all cases worldwide (Table 1).

Furthermore, the concept of islet cell transplantationoffers many perspectives [25]: 1. In contrast to pancreasorgan transplantation, islet cell availability could becomeunlimited, when strategies such as the use of xenogenicislets, engineered beta cell lines, in vitro stem cellexpansion and differentiation into insulin-producing cellsor transdifferentiation of non-pancreatic cells into betacells reach the stage of clinical applicability; 2. islet cellsmay be transplanted without chronic immunosuppressivetreatment of the recipient by making use of donor-specifictolerance induction strategies or immunoisolation sys-tems. This unique set of characteristics could finally allowto offer islet transplants alone to adults and evenadolescents and children with type 1 diabetes before thedevelopment and with the prospect of preventing suchdevastating diabetic secondary complications like end-stage renal disease, lower limb ischemia, and amputationsor blindness.

Fig. 2 Annual incidence of new cases with diabetic complications inGermany

6 Mio Diabetic Patients

About 1.6 Mio Insulin Users

300,000 T1DM 5.7 Mio T2DM

Fig. 1 Prevalence of diabetes mellitus in Germany

240 Langenbecks Arch Surg (2007) 392:239–253

This review will summarize the current status and theperspectives of pancreatic islet transplantation in patientswith type 1 diabetes mellitus.

The history of islet cell transplantation

Rudolf Virchow (1821–1902) was the first to suspect anincretory capacity of the pancreatic organ in addition to itsknown excretory capacity. Virchow’s student, Paul Langerhans,first described in his doctoral thesis (1869) clusters of cellslater named after him as islets of Langerhans. However, PaulLangerhans had no idea about the function of these cellclusters.

In April 1889, Joseph von Mering was working inHoppe Seyler’s Institute at the University of Strasbourgwhen Oskar Minkowski visited. After one of their dis-cussions on the metabolic role of the pancreatic gland, theybegan an investigation of the surgical removal of thepancreas from a dog. They found that diabetes mellitusdevelops after total pancreatectomy, providing final evi-

dence that this disease is located in the pancreas [26]. Twoyears later, Oskar Minkowski gave a lecture on December18, 1891 at the Strasbourg Society of Natural Science andMedicine, which was published in the Berliner KlinischeWochenschrift [27]. He informed the audience that his andvon Mering’s series of experimental studies providedfurther evidence that diabetes mellitus develops afterpancreatectomy as well as demonstrated for the first timethat pancreatectomy-induced diabetes can be prevented byautografting pancreatic fragments under the skin. Further-more, Minkowski concluded that something seems to bedelivered by the pancreatic gland, which facilitates sugarconsumption by the peripheral tissue. Today, of course, weall know that this “something” is the hormone insulin,which 30 years later was extracted from pancreatic tissueand successfully injected in patients with insulin-requiringdiabetes [28].

The pioneering work by Oskar Minkowski and Joseph vonMering, in particular their experimentation with the auto-transplantation of pancreatic fragments, paved the way towardclinical islet transplantations. Almost exactly 2 years after

0 1 2 3 4 5 6 7 8 9 10 11 120

10

20

30

40

50

60

70

80

90

100

months posttransplant

1990-1993 (n=82)

1994-1997 (n=118)

1998-1999 (n=37)

Fig. 4 One-year insulin inde-pendence by era (data from theInternational Islet TransplantRegistry [ITR], Giessen/Germany 1990–1999) inC-peptide negative type 1diabetic IAK/SIK recipients,in patients treated at GiessenTransplant Center [23] andin ITA recipients treated atEdmonton TransplantCenter [33]

Fig. 3 First case worldwide ofinsulin independence after islettransplantation in a type 1diabetic patient [16]

Langenbecks Arch Surg (2007) 392:239–253 241

Minkowski’s lecture, the first recorded human pancreaticfragment transplant was performed on December 20, 1893.Dr. P. WatsonWilliams and his colleague,Mr. Harsant, treateda 15-year-old boy in the Bristol Royal Infirmary in GreatBritain with the subcutaneous implantation of three pieces offreshly slaughtered sheep’s pancreas, each “the size of a Brazilnut” [29]. They observed that glycosuria was lowered;however, the patient died after a few days.

After the experience with more or less poor results withislet transplants in the early 1990s, a new protocol wasintroduced by the group in Giessen, Germany, whichsignificantly improved the 1-year insulin independence rateto 26% (Table 2 and Fig. 4) [22, 23]. Later on, a detailedreview of the cumulative world experience in clinical islettransplantation clearly highlighted several factors as beingcausative for failure in the majority of cases transplantedup until 1999 [30, 31]: 1. inadequate islet transplant mass;2. inadequate islet potency; 3. inadequate prophylaxis

against allograft rejection or autoimmunity; and 4. routineuse of toxic and diabetogenic immunosuppression aftertransplantation.

A new protocol implemented in Edmonton in 1999 wasdesigned to systemically address each of the above limi-tations. One year later, Shapiro et al. at the University ofAlberta in Edmonton, Canada reported successful reversal ofdiabetes by pancreatic islet transplantation in seven consec-utive patients [24]. The study focused on the use of islet celltransplantation alone for a subgroup of type 1 diabeticpatients with severe hypoglycemia and uncontrolled diabe-tes, but no kidney disease. The novel immunosuppressiveregimen associated with a meticulous preparation of theislets, implanted in large masses, later named the “Edmontonprotocol”, revolutionized the field of islet transplantation.The protocol adapted all the current improved techniques forpancreas procurement and isolation.

The major novel approach was to transplant an adequateislet mass through repeated islet implantations on acorticoidsteroid sparing-based immunosuppressive regi-men. Its main features include harvesting the pancreasbefore multiorgan retrieval, avoidance of prolonged cold

Table 1 Eleven institutions with ≥20 adult islet allografts in type 1diabetic patients 1990–2005

Institution Year of TX No. of cases

Edmonton 1991–2005 99Giessen 1992–2005 93Milan 1991–2005 79Brussels (Free Univ.) 1994–2005 74Minneapolis 1991–2005 66Miami 1991–2005 55Geneva 1994–2005 39GRAGIL/Geneva 1999–2005 34Nordic Network/Uppsala 2001–2005 32Philadelphia 2001–2005 30Brussels (Louvain) 2000–2005 24

591a

Data from the International Islet Transplant Registry (ITR), Giessen/Germany

a 66% of all adult islet allografts

Table 2 The Giessen islet transplantation protocol 1992–1996

Islet preparation Reagents with low endotoxin content

Pre-Tx ATG / ALGPeri-Tx Total Parenteral Nutrition (TPN)Post-Tx Prednisolone

CYA (300–400 ng/ml WB trough level)AZA (75–100 mg) or MMF (1 g b.i.d.)IV insulinNicotinamide (1 g b.i.d.)Verapamile (80 mg t.i.d.)Pentoxifylline (400 mg b.i.d.)Antioxidants: β-Carotene 15,000 IU b.i.d.Vit. C: 1,000 mg/d, Vit. E: 400 IU/d

01234567

-50 0 50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800 850 900 950 1000

0

50

100

150

200

0 50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800 850 900 950 1000

Fig. 5 First Giessen islet-after-kidney recipient, transplanted onNovember 26, 1992 achievinginsulin independence 400 daysposttransplant [8]


storage of the pancreas (<8 h), avoidance of animal serumproducts during isolation, and a target islet mass of at least11,000 islet equivalents (IEQ)/kg of recipient bodyweight,which requires islets from two to three donor preparations.They used an immunosuppressive protocol comprised ofinduction therapy with a humanized interleukin-2 (Il-2)receptor antibody (daclizumab) and maintenance therapyinvolving low-dose tacrolimus and sirolimus. Later, afollow-up in more than 50 patients treated at the Edmontonsite confirmed 1-year insulin independence rates of 80%(Fig. 4) [32, 33].

Lessons from islet cell autografts

Experience in Germany with islet cell autografts in patientsafter pancreatectomy for severe chronic pancreatitis datesback to the late 1970s when we reported the first case of

successful islet autotransplantation [34]. We did not achievefull insulin independence; however, the patient’s dailyinsulin requirement was as low as 6 units per day. In1992, Pyzdrowski et al. at the University of Minnesota inMinneapolis, USA reported a series of five patients whobecame insulin independent after intrahepatic islet auto-transplantation after total or near-total pancreatectomy forsevere chronic pancreatitis [35]. From this study and otherreports we learned that a critical mass of 300,000 isletsimplanted in the liver could reestablish and maintain insulinindependence in the setting of an autotransplantation [36,37]. Of the 275 well-documented islet cell autograftsrecorded in the International Islet Transplant Registry(ITR) in Giessen, Germany database from 1990 to 2005,48 and 75% of recipients were insulin-independent at 1 yearafter transplantation if less than or more than 300,000 isletequivalents (IEQ) per recipient were grafted, respectively(Table 3) [9]. To date, the longest period of insulin

Table 3 Islet cell autograftsfrom 1990 to 2005

Data from ITR, Giessen,Germanya Only well-documented cases

Institutions

Minneapolis 122Cincinnatti 52Leicester 45Geneva 18Indianapolis 1113 other institutions 25

No. of cases 275Insulin-independent ≥7 days (1990–2005): 88/117a(75%)Insulin-independent at ≥1 year(1990–2005+1 year follow-up):

53/110a (48%)

If more than 300,000 IEQ transplanted: 34/45a (75%)Longest insulin-independence follow-upafter total pancreatectomy:

16 y

Sydney Westmead (6)

Edmonton (86)

Miami (39)

Minneapolis (22)

NIH (6)

Northwestern (10)

U Penn (30)

Harvard (12)

Houston (13)

St Louis (8)

Geneva+GRAGIL (62)

Milan (51)

Giessen (36)

Cincinnati (6)

U. Maryland (2)

Seattle (6)

U Mass (2)

Memphis (3)

King’s (UK) (4)

Nordic Network (32)

Red = ITABlue= ITA and SIK/IAKBlack= SIK/IAK

Emory (10)Vancouver (12)Columbia NY (2) City of Hope CA (5)

Sao Paolo (3)

Shanghai (2)

UC San Francisco (2)

Carolina Med Center (2)

Tokyo (1)Chiba (1)

Brussels/Free Univ. (63)

Brussels/Louvain (31)

47 Institutions: ~ 652 patients

Budapest/Geneva (4)

Lille (19)

Seoul (Asan/Samsung) (2)

Santiago de Chile (1)

Nantes (1)

Buenos Aires (4)

Perugia (2)

Denver (3)

Bern/Geneva (3)

Royal Free (UK) (4)

Sydney Pr. of Wales (1)Oxford (UK) (1)

Innsbruck (13)Stockholm/Giessen (2)

Zurich (20)

Kyoto (5)

Fig. 6 Worldwide islet trans-plant activity 1999–2005


independence after islet autotransplantation is 16 years(Table 3). The studies with islet cell autografts proved thathuman islet transplantation is feasible, safe, and couldestablish long-lasting insulin independence.

Clinical outcomes of islet cell transplantation in type 1diabetes 1990–2006

After the Edmonton milestone report, an unprecendented,exponential increase in clinical islet transplant activitiesfollowed, with an estimated 652 patients with type 1diabetes treated at 47 institutions worldwide (Fig. 6) inthe new era (1999–2005). This represents a significantmilestone, as more patients with type 1 diabetes have now

received islet implants in the past 6 years than in the entirepreceding 30-year history of islet transplantation. Allcenters more or less use the same methods for isletisolation, purification, and implantation (Figs. 7 and 8).

Islet graft survival

Between January 1990 and December 2004, 458 well-documented islet transplant cases were reported to theInternational Islet Transplant Registry (ITR) established in1989 and maintained at our department of GiessenUniversity Hospital. Updates have been recently published[9] (http://www.med.uni-giessen.de/itr). The islet trans-plants were performed in three main recipient categories:islet-after-kidney transplants (IAK); simultaneous-islet-

Fig. 7 a–f Islet cell transplanta-tion. Islet isolation andpurification


http://www.med.uni-giessen.de/itr

kidney (SIK); and islet-transplants-alone (ITA) (Fig. 9). Isletgraft function data analysis by era shows the significantimprovement of cumulative 1-year islet graft survival andinsulin independence rates to levels of 82 and 43%, respec-tively, in the last 5 years (Fig. 5). Notably, cumulative patient1-year survival rates were 97%, with 96% in IAK recipients,96% in SIK recipients, and 100% in ITA recipients.

A study of our first 72 consecutively transplanted type 1diabetic patients 1-year posttransplant demonstrated isletallograft survival rates of 52–81% and insulin indepen-dence rates of 16–50% depending on recipient category(Table 4). The NIH-based Immune Tolerance Network,sponsored by the Juvenile Diabetes Research Foundation(JDRF), recently supported the first international transat-lantic multicenter trial in islet transplantation to study acohort of 36 patients treated with the Edmonton protocol atnine centers in North America (Boston, Edmonton, Miami,Minneapolis, Seattle, St. Louis) and Europe (Geneva,Giessen, Milan). The preliminary data indicated that theprotocol was successfully replicated, with >80% of recipientsat the three most experienced sites achieving sustained insulin

independence [39]. Success was more variable (0–63%) atthe remaining sites, reflecting not only the unique chal-lenges involved with the setting up of new islet isolationfacilities, but also experience with sirolimus-based immu-nosuppression [39, 40]. Very recently, the final 1-yearresults of this first multicenter trial was published in theNew England Journal of Medicine [41]. The rate of insulinindependence 1 year after islet transplantation was 44%,with 28% of the cases demonstrating islet graft function(significant levels of C-peptide) but no insulin indepen-dence (“partial function”) (Table 5). In other words, isletgraft function was maintained over 1 year in 72% of thecases, but 28% of the recipients experienced complete graftloss within 1 year (Table 5).

All in all, one might ask whether that much progress inhuman islet transplantation from a clinical point of view reallyhas been made over the last 30 years. To some extent, thisdepends on whether you see the glass as being half-full orhalf-empty. However, from the perspective of two renownedpioneers in the field of transplantation, Sir Peter J. Morris andAnthony P. Monaco, the glass is more than half-full [42].

Fig. 8 a–d Islet cell transplantation. Islet implantation


Prevention of hypoglycemic episodes

In a small series of islet transplants together with kidneys(SIK) in 11 recipients and kidney transplants alone (KTA)in eight recipients as control, we observed no hypoglycemicepisodes after SIK transplantation. However, those patientswith grafted kidney and maintaining insulin treatment, eachexperienced quite the same number (mean about 2) ofsevere hypoglycemic episodes (per definition: third-partyassistance required) per year as before kidney transplanta-tion. These observations led us to perform for the first time,in 1998, islet transplants (ITA) in non-uremic patients withlong-standing type 1 diabetes mellitus and hypoglycemia-associated syndrome, suffering from hypoglycemia un-awareness, defect counterregulation, and experiencingrecurrent episodes of severe hypoglycemia [43]. We found

that intraportal islet transplantation did not restore hypo-glycemia-induced glucagon secretion, but it significantlyimproved the responses of most counterregulatory hormonesand reestablished both autonomic and neuroglucopenichypoglycemia warning symptoms even in long-standingtype 1 diabetes (Fig. 10).

The Edmonton group has gained larger experience withislet transplants alone in patients suffering from recurrent,severe hypoglycemia and glycemic lability (“brittle diabe-tes”). They clearly demonstrated that islet transplantationprovides endogenous insulin that corrects glycemic labilityand is accompanied by a decrease in the number ofepisodes of hypoglycemia [44]. However, our earlierfindings of a lack of islet transplantation on the bluntedglucagon response to hypoglycemia was recently con-firmed [45]. Nonetheless, the beneficial effects onglucose stability and hypoglycemia awareness have tobe ascribed to successful islet transplantation. This wasrecently demonstrated in a case report [46]. A patientwith severe, recurrent hypoglycemia and glycemic labilityunderwent islet transplantation alone. Posttransplant, theproblems with hypoglycemia abated and excellent stableglycemic control was attained. Two and a half years afterislet transplantation, insulin had to be reinstituted at lowerdoses than before the transplant because of deteriorationin graft function. Now, occasional episodes of hypoglycemiahave occurred and some glycemic lability was recurred,although endogenous insulin secretion is still preserved [46].

Effects on diabetic secondary complications

Until now, this aspect of islet transplantation was much lessin focus of most trials. One group has observed beneficialeffects of successful pancreas and also islet transplantationson the function and survival of kidney grafts in type 1diabetic patients [47, 48]. However, the positive impact ofislet transplantation may be counterbalanced by using theassociation of two potentially nephrotoxic drugs, namely,tacrolimus and sirolimus according to the Edmontonprotocol. There is now some concern about deteriorationin renal function after islet transplants alone observed inseveral studies [24, 49, 50]. However, in a very careful studywith medically treated patiens as control group, no evidence

0 1 2 3 4 5 6 7 8 9 10 11 120

10

20

30

40

50

60

70

80

90

100


1990-1993 (n=82)

1994-1998 (n=124)

1998-2001 (n=140)

38 %37 %

[%]

1998-2000

1990-1993

1994-1998

82%1999-2004

1998-2004 (n=242)

0 1 2 3 4 5 6 7 8 9 10 11 120

10

20

30

40

50

60

70

80

90

100


1990-93 (n=82) 1994-97 (n=118) 1998-2001 (n=140)

9 %8 %

[%]

1990-1993

1994-1998

1998-2003 (n=248)

43%1999-2004

a

b

Fig. 9 Cumulative 1-year islet graft survival (a) and insulinindependence rates (b) in 458 well-documented pre-transplant C-peptide negative type 1 diabetic recipients by era. Data from theInternational Islet Transplant Registry (ITR), Giessen/Germany

Table 4 Outcomes of 1-year posttransplant in 72 consecutive casestransplanted at the German Islet Transplant Center in Giessen, Germany

One Year Follow-Up: 43 SIK; 25 IAK; 4 ITAIslet Allograft Survival

81% SIK; 52% IAK; 75% ITAInsulin Independence

16% SIK; 20% IAK; 50% ITA

Table 5 International Multicenter Trial of islet transplantation withthe Edmonton protocol in type 1 diabetes mellitus [41]

• A total of 36 subjects underwent islettransportation at 9 international sites(6 in North America, 3 in Europe; ITN/NIAID; JDRFI)

• Results at 1 Year:• Insulin Independence 44%

72%• Partial Function 28%• Complete Graft Loss before 1 Year 28%


of worsening of renal function post islet transplantation wasfound [51]. The conflicting results may be partly explainedby the initital status and function of the kidney, as reductionof kidney function might be associated with renal damagebefore islet transplantation [52]. These authors recommendthe use of the combination of tacrolimus-sirolimus only inpatients with normal kidney function [52].

Limitations of islet cell transplantation

There are major obstacles to the success of islet transplan-tation in subjects with type 1 diabetes mellitus. First, theimbalance between the islet mass engrafted and themetabolic demand determines the clinical outcome. Fromanimal experiments, it was calculated that approximately50% of the islets transferred will not engraft and primarynon-function may be the result of low functional capacity ofβ cells after the isolation procedure, of local inflammatoryand apoptotic mechanisms, cytokines, clotting elements ofthe blood, and hypoxia before revascularization of the isletsin the hepatic microenvironment [53–59]. A high metabolicdemand imposed on the islet graft results from the insulin

resistance in diabetic recipients and from diabetogenic andprobably toxic effects of high portal vein concentrations ofconventional immunosuppressive agents (cyclosporine A,tacrolimus, glucocorticoids) [60, 61]. Second, isolated isletgrafts seem to be more prone to destruction by autoimmunerecurrence and allograft rejection than whole pancreaticorgan allotransplants [62–68].

One major concern is with the waning of islet graftfunction over time. There is data from the ITR that insulinindependence after islet allografts in type 1 diabetic patientsmay last for more than 9 years (International Islet TransplantRegistry [ITR] http://www.med.uni-giessen.de/itr). The lon-gest insulin independence in a patient (SIK) transplantedwith a single-donor islet preparation at our center lasted for6.5 years. These may be single observations. However, intheir large series of islet transplants alone, the Edmontongroup observed a gradual loss of islet graft function ending-after 5 years posttransplant in an insulin independence rate ofonly 10% with a function rate (C-peptide) of about 80% [45].The benefits of persistent islet graft function (C-peptide) inthe absence of insulin independence should not be entirelydiscounted, because effective prevention of recurrent

Fig. 10 Islet transplants alone (ITA) in C-peptide-negative patientswith long-standing type 1 diabetes and hypoglycemia-associatedsyndrome. C-peptide concentrations maintained after islet transplan-tation in three cases for 30 days, two early transplant failures (upperpanels). Six hours insulin-induced hypoglycemia clamp tests per-

formed before and after islet transplantation (lower panels), demon-strating reestablished epinephrine response. Shaded boxes indicate testresponses of age-matched healthy control subjects (n=10). Adaptedfrom reference Meyer C et al. [43]


http://www.med.uni-giessen.de/itr

hypoglycemia or severe glucose lability with correction inHbA1c to a level far superior to that readily achievable withintensive insulin therapy is seen as substantial benefit.

Perspectives of islet cell transplantation

The perspectives of islet cell transplantation were exten-sively reviewed elsewhere [69, 70]. This review willtherefore report only perspectives to overcome the prob-lems with current immunosuppressive regimens and limiteddonor supply.

Tolerance induction

The ultimate goal of islet transplantation is to completelyrestore glucose homeostasis and prevent long-term diabeticcomplications without the need for maintenance immuno-suppressive therapy. Albeit the risks of malignancy and life-threatening infection have been very low, there is fear ofthese complications and medication side effects [71]. If thedegree of systemic immunosuppression could be reducedtoward allograft tolerance, islet transplantation could beapplied in the earliest stages of diabetes, includingtransplantation in children.

Tolerance induction is central to the thesis of islettransplantation. Meanwhile, the mechanisms of islet allograftrejection are better understood. At least, three levels of cell-to-cell crosstalk, between the antigen-presenting cells(APCs) and the recipient’s T cells have to be taken intoaccount. Blockage of the co-stimulatory signal (signal 2) forT-cell activation, and induction of hematopoietic chimerismare the two main and most promising strategies for toleranceinduction [72, 73]. Recent studies in non-human primatesdemonstrated that immunotolerance toward islet cells can beestablished by CD40–CD40 ligand (CD154) blockade [74,75]. Pre-implantation-stage stem cells surprisingly werecapable of inducing long-term allogeneic graft acceptancewith supplementary host conditioning [76]. However, most

strategies that successfully induce transplant tolerance inmurine models have failed upon translation into clinicaltherapies so far [77], and clinical trials with a humanizedanti-CD154 (CD40 ligand) antibody were halted because ofunexpected high rates of thromboembolic complications inkidney transplant recipients [78, 79].

Xenotransplants, stem cell therapy, and regenerativestrategies

If tolerance induction would allow a widespread use of isletallotransplantation, a further problem may suddenly emerge:huge amounts of donor islet tissue are needed. But, whereshould the islets come from? One option might be the use ofhuman pancreata from non-heart-beating donors [80] or theuse of living-donor pancreas [81] or use of pancreas fromlarge mammals. Another option is the use of alternativeresources. The pig is considered the primary alternativedonor species for islet xenografts to humans due to ethicalconsiderations, breeding characteristics, and its compatiblesize and physiology [82]. Porcine insulin has been widelyused in humans; the pig insulin molecular structure differsfrom human insulin in only one aminoacid position.

Another source for islet xenograft tissue might be fetalpancreas [83]. The cultured fetal porcine pancreas bearsseveral potential advantages: (1) it contains a largerproportion of endocrine tissue; (2) the exocrine tissueundergoes atrophy during culture; (3) the fetal tissue inheritsa considerable growth potential; and (4) it might be lessimmunogeneic. It should be noted that cell aggregates (“fetalporcine islet-like cell clusters”—FPCCs) do not trigger ahyperacute rejection when transplanted to rodents, and it islikely that they are revascularized from the surroundingtissues, thus containing recipient endothelial cells [84]. Thiscould make such cultured fetal islet tissue suitable forclinical trials with xenotransplantations.

Fetal pig proislets can be easily produced at large scale,further differentiate, mature and grow in culture or in vivoafter grafting, may be stored long term in liquid nitrogen

Fig. 11 Transdifferentiation ofhepatoma cells by gastrin/GLP-1 into beta cells. Left: trans-differentiated cells stained forinsulin; right: insulin/C-peptiderelease from transdifferentiatedcells after stimulation with glu-cose±IBMX. Adapted fromreference Jahr H et al. [126]


and can persistently reverse diabetes after xenografting andmay be more resistant to diabetogenic agents than adultislet tissue [85–91].

However, the use of pigs as a source for organs and cells tobe xenografted to humans has provoked ethical and epidemi-ological controversies [92]. Transfer of porcine endogenousretroviruses (PERV) from porcine cells to human cells hasbeen demonstrated in vitro and in vivo after xenotrans-plantation into immuno-incompetent and immunodeficientSCID mice [93–96]. However, there is until now noevidence of infection with PERV in Swedish patientswho were treated with porcine islet cell xenografts or inpatients treated with living pig tissue [97, 98]. Anotheroption to prevent recipient infection might be the use ofspecially bred PERV-free pigs. Recently, controversy inxenotransplantation has achieved a new height with thepaper by Valdes [99] reporting improved glucose homeo-stasis by cotransplantation of pig Sertoli cells andneonatal porcine islets in diabetic children. While thispreliminary observation demonstrates great potential, thereplication of these results in primates and a larger cohortof children will be required before definitive conclusionscan be drawn [100].

Stem cell therapy, the use of either embryonic or adultprogenitor cells differentiated and expanded under specialconditions to fully functional, insulin-producing beta cells,is a second approach to overcome the problems withlimited tissue supply for clinical islet transplantation indiabetes mellitus [101].

It is generally accepted that the pancreatic endocrinecells are of endodermal origin. The pathway from precursorcells to distinguished cell types, the genes and transcriptionfactors involved, and the spatial and sequential temporalorder, meanwhile, has become clear [102–107]. Recentreports on the in vitro differentiation and expansion ofembryonic stem cells of murine or human origin to insulin-producing beta cells are very promising [111–113]. Trans-planted into diabetic animals, these cells normalized bloodglucose of the recipients [108, 109].

However, ethical concerns with the research on humanembryonic material brought up the question as to whetheradult (“old”) cells can learn new tricks, i.e., may differen-tiate to insulin-producing cells. So-called Nestin-positivecells in the pancreatic duct or within the islets ofLangerhans may be relevant progenitor cells [111]. By invitro cultivation of ductal epithelial cells from adult mice,islets could be obtained, which responded in vitro toglucose stimulation and reversed diabetes when trans-planted into diabetic NOD mice [112]. A method to yieldislets through in vitro cultivation of adult human pancreaticductal cells was described recently [113].

Research in the area of stem cells has demonstratedconsiderable promise in recent years based on evidence of

pancreatic stem cell proliferation using neogenesis peptidessuch as islet neogenesis-associated protein (INGAP) [114],hepatocyte growth factor, epidermal growth factor, gastrin,glucagon-like peptide 1 (GLP-1), GLP-agonists, and DPP-4inhibitors. A recently available GLP-1 agonist (exenatide,Byetta®/Lilly) was first tested in islet-transplanted patients[115].

A third approach to overcome the limited donor tissuesupply is to make use of gene therapy for engineeringpancreatic islets [116–122]. The principal advantage of thisapproach is that autologous tissue and cells can be used andthe problems with graft rejection and disease recurrencewould probably no longer exist. For example, gut, liver, ormuscle cells have been successfully targeted for transfec-tion with the insulin-/pro-insulin gene [117, 123–125]. Agroup in Israel recently described expression of insulingenes in the liver and amelioration of hyperglycemia inmice after viral transfection of the hepatocytes with thepancreatic and duodenal homeobox (PDX)-1 gene [117].Recently, we have demonstrated that hepatoma cells can bedifferentiated to beta cells with the help of a gastrin/GLP-1mixture without the need of a viral gene transfection(Fig. 11) [126]. This is proof-of-principle for convertinghepatocytes to β cells [127].

Summary and conclusions

Islet cell transplantation has raised hope for a cure ofdiabetes for more than three decades. The failure to quicklyreach this goal has been an enormous disappointment toscientists, clinicians, and patients. However, the field ofislet transplantation has evolved and matured tremendously,has witnessed significant progress, and the results of recenthuman islet allotransplantations in patients with type 1diabetes mellitus are encouraging. At the beginning of themillenium, with the synergy of a number of importantinnovative tools, including stem cell expansion, immuno-modulation, and gene therapy, we have entered this newcentury with a solid foundation for expanding fundamentalresearch and for translating basic knowledge into clinicalapplications. The challenges will still be many, but thepotential benefit for patients with type 1 diabetes will beextraordinary. Continued international collaboration willfurther stimulate excitement in the field as innovativesolutions are created to overcome the problems with isletcell transplantation still existing.

Acknowledgments This study was supported by the NationalInstitutes of Health/National Institute of Diabetes and Digestive andKidney Diseases; Juvenile Diabetes Research Foundation Internation-al; the Bundesministerium für Bildung und Forschung, and DeutscheDiabetes-Gesellschaft. The authors are grateful to Andreas O. Schultzfor data managing of the ITR, Birte Hussmann and Stefanie Fast for


technical assistance, and Barbara Schultz for helping with themanuscript preparation.

References

1. Onkamo P, Vaananen S, Karvonen M, Tuomilehto J (1999) World-wide increase in incidence of Type I diabetes—the analysis of the dataon published incidence trends. Diabetologia 42:1395–1403

2. Wild S, Roglic G, Green A, Sicree R, King H (2004) Globalprevalence of diabetes: estimates for the year 2000 andprojections for 2030. Diabetes Care 27:1047–1053

3. The Diabetes Control and Complications Trial Research Group(1993) The effect of intensive treatment of diabetes on thedevelopment and progression of long-term complications ininsulin-dependent diabetes mellitus. N Engl J Med 329:977–986

4. Wang PH, Lau J, Chalmers TC (1993) Meta-analysis of effects ofintensive blood-glucose control on late complications of type-1diabetes. Lancet 341:1306–1309

5. Diabetes Control and Complications Trial/Epidemiology ofDiabetes Interventions and Complications Research Group(2003) Sustained effect of intensive treatment of type 1 diabetesmellitus on development and progression of diabetic nephropathy:the Epidemiology of Diabetes Interventions and Complications(EDIC) study. JAMA 290:2159–2167

6. The Diabetes Control and Complications Trial Research Group(1997) Hypoglycemia in the Diabetes Control and ComplicationsTrial. Diabetes 46:271–286

7. Sutherland DE, Gores PF, Farney AC, Wahoff DC, Matas AJ,Dunn DL, Gruessner RW, Najarian JS (1993) Evolution ofkidney, pancreas, and islet transplantation for patients withdiabetes at the University of Minnesota. Am J Surg 166:456–491

8. Bretzel RG, Browatzki CC, Schultz A, Brandhorst H, KlitscherD, Bollen CC, Raptis G, Friemann S, Ernst W, Rau WS, HeringBJ (1993) Clinical islet transplantation in diabetes mellitus—report of the Islet Transplant Registry and the Giessen Centerexperience. Diab Stoffw 2:378–390

9. International Pancreas Transplant Registry (IPTR) UpdatedSeptember 2006 (http://www.med.umn.edu/IPTR/home.html)

10. Gross CR, Limwattananon C, Matthees BJ (1998) Quality of lifeafter pancreas transplantation: a review. Clin Transplant 12:351–361

11. Ryan EA (1998) Pancreas transplants: for whom? Lancet351:1072–1073

12. Gruessner RWG, Sutherland DER, Troppmann C, Benedetti E,Hakim N, Dunn DL, Gruessner AC (1997) The surgical risk ofpancreas transplantation in the cyclosporine era: an overview.J Am Coll Surg 185:128–144

13. Manske CL (1999) Risks and benefits of kidney and pancreastransplantation for diabetic patients. Diabetes Care 22:B114–B120

14. Venstrom JM, McBride MA, Rother KI, Hirshberg B, OrchardTJ, Harlan DM (2003) Survival after pancreas transplantation inpatients with diabetes and preserved kidney function. JAMA290:2817–2823

15. Weimar B, Rauber K, Brendel MD, Bretzel RG, Rau WS (1999)Percutaneous transhepatic catheterization of the portal vein: acombined CT- and fluoroscopy-guided technique. CardiovascInterv Radiol 22:342–344

16. Scharp DW, Lacy PE, Santiago JV, McCullough CS, WeideLG, Falqui L, Marchetti P, Gingerich RL, Jaffe AS, CryerPE, Anderson CB, Flye MW (1990) Insulin independenceafter islet transplantation into type I diabetic patient. Diabetes39:515–518

17. Socci C, Falqui L, Davalli AM, Ricordi C, Braghi S, Bertuzzi F,Maffi P, Secchi A, Gavazzi F, Freschi M, Magistretti P, Socci S,

Vignali A, Carlo V, Pozza G (1991) Fresh human islettransplantation to replace pancreatic endocrine function in type 1diabetic patients. Report of six cases. Acta Diabetol 28:151–157

18. WarnockGL, KnetemanNM, Ryan EA, Rabinovitch A, Rajotte RV(1992) Long-term follow-up after transplantation of insulin-producing pancreatic islets into patients with Type 1 (insulin-dependent) diabetes mellitus. Diabetologia 35:89–95

19. Gores PF, Najarian JS, Stephanian E, Lloveras JJ, Kelley SL,Sutherland DE (1993) Insulin independence in type I diabetesafter transplantation of unpurified islets from single donor with15-deoxyspergualin. Lancet 341:19–21

20. Alejandro R, Lehmann R, Ricordi C, Kenyon NS, Angelico MC,Burke G, Esquenazi V, Nery J, Betancourt AE, Kong SS, Miller J,Mintz DH (1997) Long-term function (6 years) of islet allograftsin type 1 diabetes. Diabetes 46:1983–1989

21. Ricordi C, Lacy PE, Finke EH, Olack BJ, Scharp DW (1988)Automated method for isolation of human pancreatic islets.Diabetes 37:413–420

22. Hering BJ, Bretzel RG, Hopt UT, Brandhorst H, Brandhorst D,Bollen CC, Raptis G, Helf F, Grossmann R, Mellert J, Ernst W,Scheuermann E-H, Schoeppe W, Rau W, Federlin K (1994) Newprotocol toward prevention of early human islet allograft failure.Transplant Proc 26:570–571

23. Bretzel RG, Brandhorst D, Brandhorst H, Eckhard M, Ernst W,Friemann S, Rau W, Weimar B, Rauber K, Hering BJ, Brendel MD(1999) Improved survival of intraportal pancreatic islet cellallografts in patients with type 1 diabetes mellitus by refinedperitransplant management. J Mol Med 77:140–143

24. Shapiro AM, Lakey JR, Ryan EA, Korbutt GS, Toth E,WarnockGL,Kneteman NM, Rajotte RV (2000) Islet transplantation in sevenpatients with type 1 diabetes mellitus using a glucocorticoid-freeimmunosuppressive regimen. N Engl J Med 343:230–238

25. Bretzel RG (1999) Biological alternatives to insulin therapy. ExpClin Endocrinol Diabetes 107:S39–S43

26. von Mering J, Minkowski O (1890) Diabetes mellitus nachPankreas exstirpation. Arch Exp Pathol Pharmakol 26:37

27. Minkowski O (1892) Weitere Mittheilungen über den Diabetesmellitus nach Exstirpation des Pankreas. Berlin Klin Wochenschr29:90–94

28. Banting FG, Best CH (1922) The internal secretion of thepancreas. J Lab Clin Med 7:251–266

29. Williams PW (1894) Notes on diabetes treated with extract andby grafts of sheep’s pancreas. Br Med J 2:1303

30. Hering B, Ricordi C (1999) Islet transplantation for patients withType 1 diabetes: results, research priorities, and reasons foroptimism. Graft 2:12–17

31. Brendel M, Hering B, Schulz A, Bretzel R (1999) Newsletter No. 8 ofthe International Islet Transplant Registry Report. University ofGiessen, Germany

32. Ryan EA, Lakey JRT, Rajotte RV, Korbutt GS, Kin T, Imes S,Rabinovitch A, Elliott JF, Bigam D, Kneteman NM, WarnockGL, Larsen I, Shapiro AM (2001) Clinical outcomes and insulinsecretion after islet transplantation with the Edmonton protocol.Diabetes 50:710–719

33. Ryan EA, Lakey JRT, Paty BW, Imes G, Korbutt GS, KnetemanNM,Bigam D, Rajotte RV, Shapiro AM (2002) Successful islettransplantation: continued insulin reserve provides long-term glyce-mic control. Diabetes 51:2148–2157

34. Dobroschke J, Schwemmle K, Langhoff G, Laube H, Bretzel RG,Federlin K (1978) Autotransplantation von Langerhansschen Inselnnach totaler Duodenopankreatektomie bei einem Patienten mitchronischer Pankreatitis. Dtsch Med Wochenschr 103:1905–1910

35. Pyzdrowski KL, Kendall DM,Halter JB, Nakleh RE, SutherlandDE,Robertson RP (1992) Preserved insulin secretion and insulinindependence in recipients of islet autografts. N Engl J Med327:220–226


http://www.med.umn.edu/IPTR/home.html

36. Sutherland DE, Gruessner RW, Gores PF, Brayman K, Wahoff D,Gruessner A (1995) Pancreas transplantation: an update. DiabMetab Rev 11:337–363

37. Farney AC, Hering BJ, Nelson L, Tanioka Y, Gilmore T, Leone J,Wahoff D, Najarian J, Kendall D, Sutherland DE (1998) No latefailures of intraportal human islet autografts beyond 2 years.Transplant Proc 30:420

38. Brendel MD, Eckhard M, Brandhorst D, Brandhorst H, Winter D,Jaeger C, Jahr H, Ziegler A, Iken M, Shen H, Weimer R, Rau W,Padberg W, Bretzel RG (2003) Inselzelltransplantation—aktuellerStand und Perspektiven. Diab Stoffw 12:239–252

39. Shapiro AM, Ricordi C, Hering B (2003) Edmonton’s isletsuccess has indeed been replicated elsewhere. Lancet 362:1242

40. Ault A (2003) Edmonton’s islet success tough to duplicateelsewhere. Lancet 361:2054

41. Shapiro AMJ, Ricordi C, Hering BJ, Auchincloss H, Lindblad R,Robertson RP, Secchi A, Brendel MD, Berney T, Brennan DC,Cagliero E, Alejandro R, Ryan EA, DiMercurio B, Morel P,Polonsky KS, Reems JA, Bretzel RG, Bertuzzi F, Froud T,Kandaswamy R, Sutherland DE, Eisenbarth G, Segal M,Preiksaitis J, Korbutt GS, Barton FB, Viviano L, Seyfert-Margolis V, Bluestone J, Lakey JR (2006) International trial ofthe Edmonton protocol for islet transplantation. N Engl J Med355:1318–1330

42. Morris PJ, Monaco AP (2005) Pancreatic islet transplantation: isthe glass half-empty or half-full? Transplantation 79:1287–1288

43. Meyer C, Hering BJ, Grossmann R, Brandhorst H, Brandhorst D,Gerich J, Federlin K, Bretzel RG (1998) Improved glucosecounterregulation and autonomic symptoms after intraportal islettransplants alone in patients with type I diabetes mellitus.Transplantation 66:233–240

44. Ryan EA, Paty BW, Senior PA, BigamD, Alfadhi E, KnetemanNM,Lakey JR, Shapiro AM (2005) Five-year follow-up after clinical islettransplantation. Diabetes 54:2060–2069

45. Rickels MR, Schutta MH, Mueller R, Markmann JF, Barker CF,Naji A, Teff KL (2005) Islet cell hormonal responses tohypoglycemia after human islet cell transplantation for type 1diabetes. Diabetes 54:3205–3211

46. Ryan EA, Shapiro AMJ (2006) A patient with severe, recurrenthypoglycemia and glycemic lability who underwent islettransplantation. Nat Clin Pract Endocrinol Metab 2:349–353

47. Fiorina P, Folli F, Zerbini G, Maffi P, Gremizzi C, Di Carlo V,Socci C, Bertuzzi F, Kashgarian M, Secchi A (2003) Islettransplantation is associated with improvement of renal functionamong uremic patients with type 1 diabetes mellitus and kidneytransplants. J Am Soc Nephrol 14:2150–2158

48. Fiorina P, Venturini M, Folli F, Losio C, Maffi P, Placidi C, LaRosa S, Orsenigo E, Socci C, Capella C, Del Maschio A, Secchi A(2005) Natural history of kidney graft survival, hypertrophy, andvascular function in end-stage renal disease type 1 diabetickidney-transplanted patients: beneficial impact of pancreas andsuccessful islet cotransplantation. Diabetes Care 28:1303–1310

49. Senior PA, Zeman M, Paty BW, Ryan EA, Shapiro AMJ (2007)Changes in renal function after clinical islet transplantation: four-year observational study. Am J Transplant 7:91–98

50. Andres A, Toso C, Morel P, Demuylder-Mischler S, Bosco D,Baertschinger R, Pernin R, Bucher P,Majno PE, Buhler LH, BerneyT (2005) Impairment of renal function after islet transplant alone orislet-after-kidney transplantation using a sirolimus/tacrolimus-based immunosuppressive regimen. Transplant Int 18:1226–1230

51. Fung MA, Warnock GL, Ao Z et al (2007) The effect of medicaltherapy and islet cell transplantation on diabetic nephropathy: aninterim report. Transplantation (in press)

52. Maffi P, Bertuzzi F, De Taddeo F, Magistretti P, Nano R, Fiorina P,Caumo A, Pozzi P, Socci C, Venturini M, Del Maschio A, Secchi A(2007) Kidney function after islet transplant alone in type 1

diabetes: impact of immunosuppressive therapy on progression ofdiabetic nephropathy. Diabetes Care (Epub ahead of print)

53. Vargas F, Vives-Pi M, Somoza N, Armengol P, Alcalde L, Marti M,Costa M, Serradell L, Dominguez O, Fernandez-Llamazares J,Julian JF, Sanmarti A, Pujol-Borrell R (1998) Endotoxin contam-ination may be responsible for the unexplained failure of humanpancreatic islet transplantation. Transplantation 65:722–727

54. Kaufman DB, Platt JL, Rabe FL, Dunn DL, Bach FH, SutherlandDE (1990) Differential roles of Mac-1+ cells and CD4+ and CD8+T lymphocytes in primary nonfunction and classical rejection ofislet allografts. J Exp Med 172:291–302

55. Bottino R, Fernandez LA, Ricordi C, Lehmann R, Tsan MF, OliverR, Inverardi L (1998) Transplantation of allogeneic islets ofLangerhans in the rat liver. Effects of macrophage depletion on graftsurvival and microenvironment activation. Diabetes 47:316–323

56. Menger MD, Vajkoczy P, Leiderer R, Jager S, Messmer K (1992)Influence of experimental hyperglycemia on microvascular bloodperfusion of pancreatic islet isografts. J Clin Invest 90:1361–1369

57. Berney T, Molano RD, Cattan P, Pileggi A, Vizzardelli C, Oliver R,RIcordi C, Inverardi L (2001) Endotoxin-mediated delayed isletgraft function is associated with increased intra-islet cytokineproduction and islet cell apoptosis. Transplantation 71:125–132

58. Bennet W, Sundberg B, Groth CG, Brendel MD, Brandhorst D,Brandhorst H, Bretzel RG, Elgue G, Larsson R, Nilsson B,Korsgren O (1999) Incompatibility between human blood andisolated islets of Langerhans: a finding with implications forclinical intraportal islet transplantation? Diabetes 48:1907–1914

59. El-Ouaghlidi A, Jahr H, Pfeiffer G, Hering BJ, Brandhorst D,Brandhorst H, Federlin K, Bretzel RG (1999) Cytokine mRNAexpression in peripheral blood cells of immunosuppressedhuman islet transplant recipients. J Mol Med 77:115–117

60. Shapiro AM, Gallant H, Hao E, Wong J, Rajotte R, Yatscoff R,Kneteman N (1997) Portal vein immunosuppressant levels andislet graft toxicity. Transplant Proc 30:641

61. Drachenberg CB, Klassen DK, Weir MR, Wiland A, Fink JC,Bartlett ST, Cangro CB, Blahut S, Papadimitriou JC (1999) Isletcell damage associated with tacrolimus and cyclosporine:morphological features in pancreas allograft biopsies and clinicalcorrelation. Transplantation 68:396–402

62. Jaeger C, Hering BJ, Dyrberg T, Federlin K, Bretzel RG (1996)Islet cell antibodies and GAD65 antibodies in IDDM patientsundergoing kidney and islet after kidney transplantation. Trans-plantation 62:424–426

63. Jaeger C, Brendel MD, Hering BJ, Eckhard M, Bretzel RG(1997) Progressive islet graft failure occurs significantly earlierin autoantibody positive than in autoantibody negative IDDMrecipients of intrahepatic islet allografts. Diabetes 46:1907–1910

64. Jaeger C, Brendel MD, Eckhard M, Bretzel RG (2000) Islet auto-antibodies as potential markers for disease recurrence in clinicalislet transplantation. Exp Clin Endocrinol Diabetes 108:328–333

65. Braghi S, Bonifacio E, Secchi A, di Carlo V, Pozza G, Bosi E(2000) Modulation of humoral islet autoimmunity by pancreasallotransplantation influences allograft outcome in patients withtype 1 diabetes. Diabetes 49:218–224

66. Tyden G, Reinholt FP, Sundkvist G, Bolinder J (1996)Recurrence of autoimmune diabetes in recipients of cadavericpancreatic grafts. N Engl J Med 335:860–863

67. Halloran PF, Homik J, Goes N, Lui SL, Urmson J, Ramassar V,Cockfield SM (1997) The "injury response": a concept linkingnonspecific injury, acute rejection, and long-term transplantoutcomes. Transplant Proc 29:79–81

68. Roep BO, Stobbe I, Duinkerken G, van Rood JJ, Lernmark A,Keymeulen B, Pipeleers D, Claas FH, de Vries RR (1999) Auto-and alloimmune reactivity to human islet allografts transplantedinto type-1 diabetic patients. Diabetes 48:484–490


69. Bretzel RG, Eckhard M, Brendel MD (2004) Pancreatic islet andstem cell transplantation: new strategies in cell therapy ofdiabetes mellitus. Panmin Med 46:25–42

70. Bretzel RG, Eckhard M, Jahr H, Brendel MD (2006) Islettransplantation, stem cell transfer and regenerative therapy indiabetes mellitus. Dtsch Med Wochenschr 131:903–936

71. Ryan EA, Lakey JR, Paty BW, Imes S, Korbutt GS, Kneteman NM,Bigam D, Rajotte RV, Shapiro AM (2002) Successful islettransplantation: continued insulin reserve provides long-termglycemic control. Diabetes 51:2148–2157

72. Waldmann H (1999) Transplantation tolerance: where do westand? Nat Med 11:1245–1248

73. Acholonu IN, Ildsta ST (1999) The role of bone marrowtransplantation in tolerance: organ-specific and cellular grafts.Curr Opin Organ Transpl 4:189–196

74. Kenyon NS, Chatzipetron M, Masetti M, Ranuncoli A, Oliveira M,Wagner JL, Kirk AD, Harlan DM, Burkly LC, Ricordi C (1999)Long-term survival and function of intrahepatic islet allografts inrhesus monkeys treated with humanized anti-CD 154. Proc NatlAcad Sci USA 96:8132–8137

75. Kenyon NS, Fernandez LA, Lehmann R, Masetti M, Ranuncoli A,Chatzipetrou M, Iaria G, Han D, Wagner JL, Ruiz P, Berho M,Inverardi L, Alejandro R, Mintz DH, Kirk AD, Harlan DM (1999)Long-term survival and function of intrahepatic islet allografts inbaboons treatedwith humanized anti-CD154. Diabetes 48:1473–1481

76. Faendrich F, LinX, Chai GX, SchulzeM,GantenD,BaderM,Holle J,Huang DS, Parwaresch R, Zavazava N, Binas B (2002) Preimplan-tation-stage stem cells induce long-term allogenic graft acceptancewithout supplementary host conditioning. Nat Med 8:171–178

77. Chong AS, Yin D, Boussy IA (2002) Transplantation tolerance:of mice and men. Graft 5:27–33

78. Kawai T, Andrews D, Colvin RB, Sachs DH, Cosimi AB (2000)Thromboembolic complications after treatment with monoclonalantibody against CD40 ligand. Nat Med 6:114

79. Kirk AD, Harlan DM (2000) Thromboembolic complicationsafter treatment with monoclonal antibody against CD40 ligand(reply). Nat Med 6:114

80. Markmann JF, Deng S, Desai NM,HuangX, Velidedeoglu E, FrankA, Liu C, Brayman KL, Lian MM, Wolf B, Bell E, Vitamaniuk M,Doliba N, Matschinsky F, Markmann E, Barker CF, Naji A (2003)The use of non-heart-beating donors for isolated pancreatic islettransplantation. Transplantation 75:1423–1429

81. Matsumoto S, Okitsu T, Iwanaga Y, Noguchi H, Nagata H,Yonekawa Y, Yamada Y, Fukuda K, Tsukiyama K, Suzuki H,Kawasaki Y, Shimodaira M, Matsuoka K, Shibata T, Kasai Y,Maekawa T, Shapiro J, Tanaka K (2005) Insulin independence afterliving-donor distal pancreatectomy and islet allotransplantation.Lancet 365:1642–1644

82. Evans RW (2001) Coming to terms with reality: why xeno-transplantation is a necessity. In: Platt JL (ed) Xenotransplanta-tion. ASM, Washington, DC. pp 29–51

83. Brown J, Danilovs JA, Clark WR, Mullen YS (1984) Fetalpancreas as a donor organ. World J Surg 8:152–157

84. Korsgren O (1991) Xenotransplantation of fetal porcine islet-likecell clusters in diabetes mellitus: an experimental and clinicalstudy. Acta Univ Upsal 295:1–40

85. KorsgrenO, Sandler S, LandströmA, Jansson L,AnderssonA (1988)Large-scale production of fetal porcine pancreatic islet-like cellclusters. An experimental tool for studies of islet cell differentiationand xenotransplantation. Transplantation 45:509–514

86. KorsgrenO, Jansson L, Eizirik D, AnderssonA (1991) Functional andmorphological differentiation of fetal porcine islet-like cell clustersafter transplantation into nude mice. Diabetologia 34:379–386

87. Liu X, Federlin KF, Bretzel RG, Hering BJ, Brendel MD (1991)Persistent reversal of diabetes by transplantation of fetal pigproislets into nude mice. Diabetes 40:858–866

88. Liu X, Brendel MD, Hering BJ, Bretzel RG, Federlin K (1992)Comparison of the potency of fetal pig pancreatic proislets andfragments to reverse diabetes. Transplant Proc 24:987

89. Liu X, Brendel MD, Klitscher D, Brandhorst H, Hering BJ,Federlin KF, Bretzel RG (1993) Successful cryopreservation offetal porcine proislets. Cryobiology 30:262–271

90. Liu X, Brendel MD, Brandhorst D, Brandhorst H, Hering BJ,Federlin K, Bretzel RG (1994) Reversal of diabetes in nude miceby transplantation of cryopreserved fetal porcine proislets.Transplant Proc 26:707–708

91. Bretzel RG, Liu X, Hering BJ, Brendel M, Federlin K (1995)Cryopreservation transplantation and susceptibility to diabeto-genic agents of fetal porcine proislets. Xenotransplantation2:133–138

92. Bach FH, Fishman JA, Daniels N, Proimos J, Anderson B,Carpenter CB, Forrow L, Robson SC, Fineberg HV (1998)Uncertainty in xenotransplantation: individual benefit versuscollective risk. Nat Med 4:141–144

93. Patience C, Takeuchi Y, Weiss RA (1997) Infection of humancells by an endogenous retrovirus of pigs. Nat Med 3:275–276

94. Martin U, Kiessig V, Blusch JH, Haverich A, von der Helm K,Herden T, Steinhoff G (1998) Expression of pig endogenousretrovirus by primary porcine endothelial cells and infection ofhuman cells. Lancet 352:666–667

95. Van der Laan LJ, Lockey C, Griffeth BC, Frasier FS, Wilson CA,Onions DE, Hering BJ, Long Z, Otto E, Torbett BE, Salomon DR(2000) Infection by porcine endogenous retroviruses after isletxenotransplantation in SCID mice. Nature 407:90–94

96. Deng YM, Tuch BE, Rawlinson WD (2000) Transmission ofporcine endogenous retroviruses in severe combined immuno-deficient mice xenotransplanted with fetal porcine pancreaticcells. Transplantation 70:1010–1016

97. Heneine W, Tibell A, Switzer WM, Sandstrom P, Rosales GV,Mathews A, Korsgren O, Chapman LE, Folks TM, Groth CG(1998) No evidence of infection with porcine endogenousretrovirus in recipients of porcine islet-cell xenografts. Lancet352:695–699

98. Paradis K, Langford G, Long Z, Heneine W, Sandstrom P,Switzer WM, Chapman LE, Lockey C, Onions D, Otto E (1999)Search for cross-species transmission of porcine endogenousretrovirus in patients treated with living pig tissue. Science285:1236–1241

99. Valdes R (2002) Xenotransplantation trials. Lancet 359:2281100. Birmingham K (2002) Skepticism surrounds diabetes xenograft

experiment. Nat Med 8:1047101. Soria B, Skoudy A, Martin F (2001) From stem cells to beta cells:

new strategies in cell therapy of diabetes mellitus. Diabetologia44:407–415

102. Edlund H (1958) Transcribing the pancreas. Diabetes 47:1817–1823

103. Stoffers DA, Zinkin NT, Stanojevic V, Clarke WL, Habener JF(1997) Pancreatic agenesis attributable to a single nucleotidedeletion in the human IPF1 gene coding sequence. Nat genet15:106–110

104. Apelqvist A, Li H, Sommer L, Beatus P, Anderson DJ, Honjo T,Hrabe de Angelis M, Lendahl U, Edlund H (1999) Notchsignalling controls pancreatic cell differentiation. Nature 400:877–881

105. Gradwohl G, Dierich A, Le Meur M, Guillemot F (2000)Neurogenin 3 is required for the development of the fourendocrine cell lineages of the pancreas. Proc Natl Acad SciUSA 97:1607–1611

106. Sosa-Pineda B, Chowdhury K, Torres M, Oliver G, Gruss P(1997) The Pax 4 gene is essential for differentiation of insulin-producing beta cells in the mammalian pancreas. Nature386:399–402


107. Wilson ME, Scheel D, German MS (2003) Gene expressioncascades in pancreatic development. Mech Dev 120:65–80

108. Soria B, Roche E, Berna G, Leon-Quinto T, Reig JA, Martin F(2000) Insulin-secreting cells derived from embryonic stem cellsnormalize glycemia in streptozotocin-induced diabetic mice.Diabetes 49:157–162

109. Lumelsky N, Blondel O, Laeng P, Velasco I, Ravin R, McKay R(2001) Differentiation of embryonic stem cells to insulin-secretingstructures similar to pancreatic islets. Science 292:1389–1394

110. Assady S, Maor G, Amit M, Itskovitz-Eldor J, Skorecki KL,Tzukerman M (2001) Insulin production by human embryonicstem cells. Diabetes 50:1691–1697

111. Zulewski H, Abraham EJ, Gerlach MJ, Daniel PB, Moritz W,Müller B, Vallejo M, Thomas MK, Habener JF (2001)Multipotential nestin-positive stem cells isolated from adultpancreatic islets differentiate ex vivo into pancreatic endocrine,exocrine, and hepatic phenotypes. Diabetes 50:521–525

112. Ramiya VK, Maraist M, Arfors KE, Schatz DA, Peck AB,Cornelius JG (2000) Reversal of insulin-dependent diabetesusing islets generated in vitro from pancreatic stem cells. NatMed 6:278–282

113. Bonner-Weir S, Taneja M, Weir GC, Tatarkiewicz K, Song KH,Sharma A, O’Neil JJ (2000) In vitro cultivation of human islets fromexpanded ductal tissue. Proc Natl Acad Sci USA 97:7999–8004

114. Rafaeloff R, Pittenger GL, Barlow SW, Qin XF, Yan B,Rosenberg L, Duguid WP, Vinik AI (1997) Cloning andsequencing of the pancreatic islet neogenesis in hamsters. J ClinInvest 99:2100–2109

115. Ghofaili KA, Eung M, Ao Z, Meloche M, Shapiro RJ, WarnockGL, Elahi D, Meneilly GS, Thompson DM (2007) Effect ofexenatide on beta cell function after islet transplantation in type 1diabetes. Transplantation 83:24-28

116. Soria B, Andreu E, Berna G, Fuentes E, Gil A, Leon-Quinto T,Martin F, Montanya E, Nadal A, Reig JA, Ripoll C, Roche E,Sanchez-Andres JV, Segura J (2000) Engineering pancreaticislets. Eur J Physiol 440:1-18

117. Cheung AT, Dayanandan B, Lewis JT, Korbutt GS, Rajotte RV,Bryer-Ash M, Boylan MO, Wolfe MM, Kieffer TJ (2000)

Glucose-dependent insulin release from genetically engineeredK cells. Science 290:1959–1962

118. Ferber S, Halkin A, Cohen H, Ber I, Einav Y, Goldberg I,Barshack I, Seijffers R, Kopolovic J, Kaiser N, Karasik A (2000)Pancreatic and duodenal homeobox gene 1 induces expression ofinsulin genes in liver and ameliorates streptozotocin-inducedhyperglycemia. Nat Med 6:568–572

119. Yang L, Li S, Hatch H, Ahrens K, Cornelius JG, Petersen BE,Peck AB (2002) In vitro trans-differentiation of adult hepaticstem cells into pancreatic endocrine hormone-producing cells.Proc Natl Acad Sci USA 99:8078–8083

120. Ber I, Shternhall K, Perl S, Ohanuna Z, Goldberg I, Barshack I,Benvenisti-Zarum L, Meivar-Levy I, Ferber S (2003) Functional,persistent, and extended liver to pancreas transdifferentiation.J Biol Chem 278:31950–31957

121. Horb ME, Shen CN, Tosh D, Slack JM (2003) Experimentalconversion of liver to pancreas. Curr Biol 13:105–115

122. Kojima H, Fujimiya M, Matsumura K, Younan P, Imaeda H,Maeda M, Chan L (2003) NeuroD-betacellulin gene therapyinduces islet neogenesis in the liver and reverses diabetes inmice. Nat Med 9:596–603

123. Lee HC, Kim SJ, Kim KS, Shin HC, Yoon JW (2000) Remissionin models of type 1 diabetes by gene therapy using a single-chaininsulin analogue. Nature 408:483–488

124. Shaw JAM, Delday MI, Hart AW, Docherty K (2002)Secretion of bioactive human insulin following plasmid-mediated gene transfer to non-neuroendocrine cell lines,primary cultures and rat skeletal muscle in vivo. J Endocrinol172:653–672

125. Riu E, Mas A, Ferre T, Pujol A, Gros L, Otaegui P, Montoliu L,Bosch F (2002) Counteraction of type 1 diabetic alterations byengineering skeletal muscle to produce insulin: insights fromtransgenic mice. Diabetes 51:704–711

126. Jahr H, Wagner S, Brendel M, Bretzel RG (2005) Gastrin-induced insulin production in hepatocyteG2 cells. Diabetologia48 (suppl 1):A153

127. Kahn A (2000) Converting hepatocytes to β-cells—a newapproach for diabetes? Nat Med 6:505–506


Documents

Islet cell transplantation todaydcl3/Ref_2007-Aug-17/islet...Results Data analysis of islet cell transplants performed in the last 5 years (1999–2004) shows at 1 year after adult