378

plasma from patients with Christmas disease very little. Theshortening of the clotting-times of haemophilia-A plasma wasmuch more pronounced. Such a discrepancy is difficult to

ascribe to thromboplastin.

Mayo Clinic and Foundation,Rochester, Minnesota 55901, U.S.A.

E. J. W. BOWIEC. A. OWEN

***This letter has been shown to Dr Blecher, whose reply fol-lows.-ED.L.

SiR,—The claim by Dr Bowie and Dr Owen that they pre-viously demonstrated the synthesis of factor vm coagulant byleucocytes is most directly refuted by the evidence in their ownpapers.l 2 In these it is specifically stated2 that the "factor vmactivity" was not reduced by incubation with an anti-fac-tor-vm antibody. It is also stated that "in the leucocyte cul-tures, factor vm levels were reduced to virtually zero by centri-fugation for 30 min at 25,000 g" and that "the activity wasstable for 24 h at room temperature". These are not the pro-perties of factor vm; they are compatible with those of leuco-cyte thromboplastin. The evidence that the activity they foundmight have been factor vm was that it shortened the clotting-time of factor vm-dencient plasma. This, however, leucocytethromboplastin does equally well, and since their papersappeared it has been shown convincingly by several workers,including their co-author Dr Zacharski, that leucocytes orfibroblasts incubated in similar manner to that in their experi-ments develop a potent tissue-factor-like thromboplastin acti-vity.3-6We cannot explain the discrepancy they mention: that the

activity they found hardly shortened the clotting-time of factorix-deficient plasma. Their observation, however, is in conflictwith all the subsequent studies, including those of their formerco-author two years later6 and ourselves (unpublished). Thesestudies have shown that when leucocytes3 4 7 or fibroblasts5 6are incubated, activity develops within them which shortensthe clotting-times of both factor-viii-deficient and factor-ix-deficient plasmas.

’

For these reasons, and in view of their own evidence quotedabove showing clearly that their activity was not factor vm,Bowie and Owen’s claim to have made the "original observa-tion that leucocytes synthesise factor vm coagulant activity"does not seem to be at all well founded.

Department of Hæmatology,General Hospital,Nottingham NG1 6HA T. E. BLECHER

CELL-SURFACE MARKERS IN LYMPHOBLASTICLEUKÆMIA

SIR,-We have two comments on the letter by Dr Kumarand colleagues (July 15, p. 164). B-cell numbers falling withdelay from time of sampling of the blood has happened to usin four cases this year. The first two patients certainly hadB-cell leukxmia, with more than 80% staining with surfaceimmunoglobulin in both instances; in posted samples the per-centage staining was negligible. In both instances the cells

regenerated surface immunoglobulin after trypsinisation andculture overnight. In the second two samples, the initial sur-

1. Zacharski, L. R., Bowie, E. J. W., Titus, J. L., Owen, C. A., Jr. Proc. StaffMeet. Mayo Clin. 1968, 43, 617.

2. Zacharski, L. R., Bowie, E. J. W., Titus, J. L., Owen, C. A., Jr. ibid. 1969,44, 784.

3. Lerner, R. G., Goldstein, R., Cummings, G. Proc, Soc. exp. Biol. Med. 1971,138, 145.

4. Loeb, W.F., Wall, R.L.J. Lab. clin. Med. 1972, 79, 778.5. Green, D., Ryan, C., Malandruccolo, N., Nadler, H. L. Blood, 1971, 37, 47.6. Zacharski, L. R., McIntyre, O. R. Thromb. Diath. hæmorrh. 1971, 26, 493.7. Niemetz, J. Proc. Soc. exp. Biol. Med. 1972, 139, 1276.

face immunoglobulin level was high when the sample wastested fresh and low after posting, but after trypsinisation andculture the cells failed to regenerate immunoglobulin. Thisstrongly suggests the need for this test to separate out thosecells to which circulating immunoglobulin adheres, includingnon-B leukaemic cells which themselves are not producingimmunoglobulin, from the true B-lymphoid type. These twopatients both had lymphomas with leukaemic transformationand both had high lymphocyte-counts and low blast-counts.Accumulating evidence on cell-surface markers stresses theneed for a whole battery of tests, the results being consideredtogether before the leukaemic-cell type is decided on. We arenot yet in a position to tailor treatment to cell type, but thattime is fast approaching; furthermore subcategorisation isessential for discussing prognosis with the family and for

analysis of survival curves.

Department of Child Life and Health,University of Edinburgh,Edinburgh EH9 1UW

O. B. EDENE. M. INNES

DOSE OF CHENODEOXYCHOLIC ACID FORGALLSTONE DISSOLUTION

SIR,-Now that doctors in Britain are free to prescribechenodeoxycholic acid (C.D.C.A.) for their gallstone patients, anarticle from a reputable department about the dose of C.D.C.A.is indeed timely (May 27, p. 1112). Unfortunately, however,the views expressed are, to say the least, controversial. DrBateson and his colleagues’ main theme is that patients shouldbe given fixed doses of C.D.C.A. unrelated to body-weight. Webelieve that, on this advice, some patients will receive inade-quate amounts of C.D.C.A. which could result in months, oreven years, of ineffective treatment.

By citing, and often misquoting, a few selected and non-- representative references in their introduction, the authors

create the impression that there is widespread confusion aboutthe doses of C.D.C.A. recommended by others. In fact, there isa large body of agreement among investigators throughout theworld about how the dose should be tailored to the patient’sneeds. They give four references, two of which came from ourown unit at different stages in the evolution of our knowledgeabout C.D.C.A. Contrary to what they suggest, in an out-of-datestudy’ which was published in these columns four years ago,we did not find significant changes in biliary cholesterol satu-ration with 250-375 mg C.D.c.A./day. Indeed in that paper,although we talked about absolute doses of C.D.C.A., we alsoshowed for the first time that there was a significant relation-ship between biliary cholesterol saturation and the dose ofC.D.C.A. related to body-weight. Our second references in thiscontext was again misrepresented by the implication that wewere in favour of doses of 750-1000 mg/day. However, basedon an analysis of those factors which we found influencedC.D.C.A.’s efficacy in dissolving gallstones, we stressed that thedose of C.D.C.A. should be related to body-weight and that theoptimal dose was 14-15 mg C.D.C.A. kg-lday-1. Since then,this recommendation has been amply confirmed by othermajor investigators throughout the world. 3-5

There may be no a-priori reason for believing that the dosemust be related to body-weight, but we emphatically deny thatbasing the daily dose of C.D.C.A. on body-weight is "an un-

necessary complication". Until recently, the Dundee workerswere reluctant to concede that it was ever necessary to usemore than 750 mg C.D.c.A./day. Only now (since January,

1. Mok, H. Y. I., Bell, G. D., Dowling, R. H. Lancet, 1974, ii, 253.2. Iser, J. H., Dowling, R. H., Mok, H. Y. I., Bell, G. D. New Engl. J. Med.

1975, 293, 378.3. Thistle, J. L., Hofmann, A. F., Ott, B. J., Stephens, D. H.J. Am. med. Ass.

1978, 239, 1041.4. Barbara, L., Roda, E., Roda, A., et al. Digestion, 1976, 14, 209.5. Fromm, H., Erbler, H. C., Eschler, A., Schmidt, F. W. Klin. Wschr. 1976,

54, 1125.6. Bateson, M. C., Ross, P. E., Murison, J., Bouchier, I. A. D. Gut, 1977, 18,

A419, A976.

379

1977) that they have tried a dose of 1000 mg/day do they findthat they too are achieving more successful gallstone dissolu-tion rates than before. 46-6% of their patients treated with the1000 mg C.D.C.A. dose "responded to dissolution therapy"compared with 30% given the 750 mg dose despite the fact that61% of their patients (17 out of 28) given 1000 mgc.D.c.A./day had "large" gallstones compared with only 37.5%(15 out of 40) given 750 mg/day. Since the 1000 mg C.D.C.A.dose corresponds to mean levels of 14.7-14.9 mg kg-’day-1,one could, with equal validity, argue that Bateson and his col- ’leagues have finally come to the same conclusion reached byIser et al. three years ago! Indeed it seems that they have hadto increase their C.D.C.A. doses to levels equivalent to 14-15 mgkg-lday-1 in 24 of their patients because their gallstones per-sisted despite treatment with lower C.D.C.A. doses.No-one debates that small doses of C.D.C.A. (250-500 mg/

day) will occasionally dissolve gallstones. But surely we needto define not the minimum dose of C.D.C.A. (which works inonly the occasional patient) but the optimum dose which willbe effective in the large majority of patients. In support of theirclaims about the efficacy of smaller C.D.C.A. doses, Bateson etal. quote a widely misunderstood abstract by Danzinger fromWinnipeg. But, as the authors must now be aware. Danzigerhimself stated publicly at a recent International Bile Acid

Meeting in Freiburg that he too believed the optimum dose ofC.D.C.A. to be not 250-500 mg or even 3-4 mg C.D.C.A. kg-1-day-’ (again doses which occasionally dissolve stones) but12-15 mgkg-1day-1.We agree that there are occasional exceptions to the rule

that gallstones dissolve only when fasting duodenal bile hasbeen rendered unsaturated in cholesterol by treatment. But,provided that one considers only "concentrated" samples ofduodenal bile arbitrarily containing >20 mmol/1 bile salts, inour experience these exceptions are very rare. However, it isunreasonable to imply, as Bateson and colleagues do, that gall-stone "dissolution may occur in the absence of pronounced orindeed any change in cholesterol content" of bile. (Cholesterolcontent is an imprecise phrase since neither cholesterol concen-tration nor moles percent cholesterol adequately describe thesaturation of bile with cholesterol). Of the three referenceswhich the authors quote to support this statement, one was the

original 1972 study8 from the Mayo Clinic based on only 7pa-tients, while the other two were from the senior author’s ownstudies. Indeed the results of bile-lipid analyses in one of theseprevious studies9 are so much at variance with the findings inother published work, and indeed with the pattern of resultsin the present article, that one must seriously question the val-idity of the methods used by the authors at that time. Fur-thermore, in the present study bile lipids were measured beforeand during treatment in only 14 out of 45 patients treated with750 mg C.D.C.A. and in only 6 out of 40 patients who weregiven 1000 mg C.D.c.A./day. Can one really argue against theusefulness of bile lipid analysis as a predictor of subsequentgallstone dissolution when this was studied in just 6 patientsgiven the 1000 mg dose?How can the authors justify such statements as "biliary lipid

analysis only (our italics) leads to conclusions about groups"?This is completely contrary to our experience. Although we toothink that it is both impractical and unnecessary for non-spe-cialist units to monitor. the bile-lipid response to C.D.C.A. in allgallstone patients, nonetheless such analyses have yielded in-valuable information in individual cases and have helped todefine groups of patients who do not respond predictably to theusual recommended doses of C.D.C.A.IO 11

7. Danzinger, R. G. Gastroenterology, 1977, 72, 1042 (abst).8. Danzinger, R. G., Hofmann, A. F., Schoenfield, L. H., Thistle, J. L. New

Engl.J. Med. 1972, 286, 1.9. James, O., Cullen, J., Bouchier, I. A. D. Q.Jl. Med. 1975, 44, 349.

10. Iser, J H., Maton, P. N., Murphy, G. M., Dowling, R. H. Br. med. J. 1978,i, 1509.

11. Maton, P. N., Dowling, R. H. Eur.J. clin. Invest. (in the press).

Bateson and his colleagues come to the surprising conclu-sion that gallstone size did not influence the response to

C.D.C.A. treatment. Not only is this finding contrary to firstprinciples but it also conflicts with a large body of publishedevidence from around the world which shows that the smallerthe gallstone, the more rapid its dissolution.

Gastroenterology Unit,Department of Medicine,Guy’s Hospital and Medical School,London SE1 9RT

R. HERMON DOWLING

PAUL N. MATON

*** This letter has been shown to Dr Bateson and colleagueswhose reply follows.-ED. L.

SIR,-We are grateful to Professor Dowling and Dr Matonfor their comments on’our paper dealing with a comparison offixed doses of C.D.C.A. It is a serious allegation to be accusedof misquoting the literature and we take this opportunity toreply. Our interpretation of the paper by Mpk et al.l is that4 of 7 patients receiving 250 mg of C.D.C.A. daily showed animprovement in biliary cholesterol saturation. This may not be"significant" statistically but it is impressive clinically. On re-reading the paper by Iser et al. we believe that the authorsstated quite clearly that they favoured a maintenance dose ofC.D.C.A. of 750-1000 mg daily.

Dowling’s views and ours do not differ on the dose ofC.D.C.A. required for the typical patient with gallstones. Ourcommunication made it clear that we no longer believe that750 mg/day is adequate and now favour 1000 mg/day. This isthe equivalent of 14-15 mg/kg body-weight/day for many pa-tients and Dowling is correct in saying that we have come tothe same conclusions as Iser et awl. It is a matter of opinionwhether it is easier to prescribe according to body-weight or bya fixed dose, but in our experience a dose of 1000 mg will besufficient for the great majority of patients. As Dowling wellknows, the exceptionally obese patient appears to be resistantto "conventional" doses of C.D.C.A., however prescribed. Wefind it difficult to follow the argument regarding the thera-peutic effect of 250-500 mg/day because at no time have werecommended this dose.

Dowling criticises the conclusions of our 19753 paper. Hav-ing the benefit of greater experience we agree that these resultswere surprising. The reason is not invalid methodology, as sug-gested by Dowling and Maton, but rather that we did not thendiscard "dilute" samples of duodenal aspirate as we, and otherworkers including Dowling, do now.A review of the published data on C.D.C.A. therapy makes it

clear that many workers have had individual patients whosegallstones appear to dissolve but in whom "spot" samples offasting duodenal bile have not been consistently unsaturated.Indeed the reverse has also been observed and an example canbe found in the paper by Iser et awl. This is the point we wishedto emphasise in our paper. We would not deny that cholesterolunsaturation of bile is a prerequisite for gallstone dissolutionand the data for the group as a whole bears this out. It is

recognised that a spot sample does not necessarily reflect thecomposition of bile throughout the 24 h and it is quite likelythat a fasting early morning specimen is indicative of the high-est degree of biliary cholesterol saturation in the patient dur-ing the 24 h period.We too are surprised that gallstone size does not influence

the response to C.D.C.A. therapy. There is no immediate

explanation for this but we wonder whether the anomaly doesnot reflect the relative inaccuracy of attempting to documentgallstone size radiologically.

University Department of Medicine,Ninewells Hospital,Dundee DD1 9SY

M. C. BATESONP. E. Ross

J. MURISONI. A. D. BOUCHIER

1. Mok, H. Y. I., Bell, G. D., Dowling, R. H. Lancet, 1974, ii, 253.2. Iser, J. H., Dowling, R. H., Mok, H. Y. I., Bell, G. D. New Engl. J. Med.

1975, 293, 379.3. James, O., Cullen, J., Bouchier, I. A. D. Q. Jl Med. 1975, 44, 349.