Monoclonal gammopathy-

associated renal lesions

Sanjeev Sethi, MD, PhD

2nd International Renal Conference Brugge 2018

Sanjeev Sethi, MD, PhD

Department of Laboratory Medicine and Pathology

Immunoglobulin G molecule

Paul Sanders, University of

Alabama at Birmingham

Some background�

• Intact Ig not filtered through glomerular capillary

walls

• Free light chains: approx. 500 mg/day are • Free light chains: approx. 500 mg/day are

produced by lymphoid tissue, and small

amounts of light chain filter through, most are

reabsorbed by proximal tubules

Glomerular ultrafiltration of

macromolecules (““““classical view””””)

Paul Sanders, University of

Alabama at Birmingham

Monoclonal Gammopathy

• The term monoclonal gammopathy refers to the overproduction of a monoclonal Ig (MIg) resulting from the clonal proliferation of immunoglobulin (Ig)-producing plasma cells or B lymphocytes .

• In most patients, the Ig is detected in the blood or the urine as a monoclonal Ig (monoclonal (M) protein)

• In most patients, there is also secretion of the light chain component • In most patients, there is also secretion of the light chain component of the Ig molecule (kappa or lambda light chains) in addition to the intact heavy Ig, e.g. IgGκ, IgMλ, etc., suggesting dysregulation of the normal antibody synthetic pathways

• In some instances, the neoplastic cells lose the ability to synthesize the normal heavy chain component of the Ig molecule, and instead secrete only kappa or lambda light chains

Laboratory techniques for detection of MIg

• Serum (S) and urine (U) protein electrophoresis (PEP)-Band or a

peak

• Immunofixation electrophoresis (IFE)- use of antibody to identify the

specific MIg

• Serum free light chain (FLC) assays provide a sensitive quantitation • Serum free light chain (FLC) assays provide a sensitive quantitation

of total serum free (unbound) kappa light chain and lambda light

chain-The presence of a kappa clone or lambda clone is inferred

from an abnormal ratio

•

• Bone marrow biopsy and aspiration Tissue detection of the plasma

cell or B lymphocyte clone requires a bone marrow biopsy and

aspiration, lymph node biopsy or extranodal biopsy, as appropriate,

with adjunct flow cytometry and molecular immunophenotyping.

Hematologic conditions associated with

Monoclonal Ig-Renal Disease

Plasma cell dyscrasia B cell lymphoproliferative disorders

Malignant Non malignant/ Malignant Non malignant/Malignant Non malignant/

premalignantMalignant Non malignant/

premalignant

Waldenström

macroglobulinemia

Multiple

Myeloma/

plasmacyto

ma

MGRS B-cell lymphoma/leukemia MGRS

(Dangerous

B-cell clones)

Smoldering

multiple

myeloma

Diagnostic Criteria of Plasma Cell Dyscrasias

MGUS SMM MM

M-spike < 3 g/dL ≥ 3 g/dL ≥ 3 g/dL

Bone Marrow PC < 10% ≥ 10% ≥ 10%

Hypercalcemia (C) absent absent +/-

Renal impairment (R) absent* absent +/-Renal impairment (R) absent* absent +/-

Anemia (A) absent absent +/-

Lytic lesions (B) absent absent +/-

Kyle et al. Leukemia 2010

Talamo et al. Clin Lymphoma, Myeloma & Leukemia. 2010

Treatment Not recommended Only high risk Yes

Criteria for MGUS, MGRS, SMM and MM

MGUS MGRS Smoldering

multiple myeloma

Multiple

myeloma

<10% BMPC

AND

<10% BMPC

AND

≥10%-60% bone marrow

plasma cells

OR

•Clonal plasma cell

disorder, AND 1 or

more of following MDE:

≥60% BMPC

<3 gm/dL M protein <3 gm/dL M protein

AND

≥3 gm/dL serum M protein

OR

≥500 mg/24h urinary M

protein

≥100 FLC ratio

No end organ

damage

MIg-associated renal

disease

End organ may be involved CRAB features

(hypercalcemia, renal

failure, anemia and

bone lesions)

>1 MRI focal lesion

No myeloma

defining event

(MDE)

No MDE No MDE MDE present

MGRS= Monoclonal gammopathy of renal significance;

MIg causing renal disease in the absence of a malignancy-

SMM/MM/Lymphoma/LeukemiaSethi S, Rajkumar V, D’Agati V

submitted

Sethi S, Rajkumar V, D’Agati V

submitted

Sethi S, Rajkumar V, D’Agati V

Light chain proximal tubulopathy

Monoclonal Ig-associated renal lesions

Paul Sanders, Birmingham, AL

(NKF, 2012)

• Amyloidosis

• PGNMID

• MIDD

• Immunotactoid/fibrillary GN

Cast nephropathy

76%76%

Patient # 1

• 61-year old man presented with acute renal failure and back

pain.

• Serum creatinine 13.8 mg/dL.

• UA 2+ protein and 2+ blood.

• All serology's including ANCA were negative• All serology's including ANCA were negative

• Serum electrophoresis showed an M spike, urine and serum

immunofixation showed IgG lambda

Hyaline vs. myeloma casts

lambda

In this case, casts stain for lambda light

chains, and are negative for kappa light chains

Cast nephropathy, lambda light chain type

kappa

• Kidney, needle biopsy: Cast nephropathy (myeloma

kidney), lambda light chain type

- Casts form due to interaction of the filtered light chains with Tamm-

Horsfall proteinHorsfall protein

- a binding domain for FLC on THP, varying affinity

– Myeloma cast nephropathy is most common renal lesion associated

with MM, and more than 90% of the patients with cast nephropathy

have MM. Cast nephropathy is considered a myeloma-defining event,

and hence is incompatible with a diagnosis of MGUS/MGRS

Patient # 2

• 69-year old man with hematuria, proteinuria, and

acute renal failure

• Serum creatinine 2.04 mg/dL

• Urinary protein 2.8 gms/24 hours• Urinary protein 2.8 gms/24 hours

• Electrophoresis studies show lambda light chains

Differential diagnosis of

nodular glomerulosclerosis

1. Amyloidosis

2. Diabetes

3. MPGN

4. Chronic TMA

5. And this lesion

kappa

lambda

Kidney, needle biopsy: Light chain deposition

disease, lambda light chain type

– Exposed portions of light/heavy chains, that allows for spontaneous

oligomers and aggregates to form

– Cationic isoelectric points which may favor binding to basement

membranes

– Activate mesangial cells to secrete matrix– Activate mesangial cells to secrete matrix

– In a recent study, >95% of the patients have a detectable monoclonal

gammopathy, and 59% of the patients had MM.

– In another study of 34 patients of MIDD, 39% of the patients had MM

and 39% were diagnosed with MGRS. In approximately 10% of the

patients no hematological abnormality is detected.

Patient # 3

• Mr. DR is 71 year old man with history of diabetes presenting

with increasing proteinuria and edema

• Serum creatinine 1.6 mg/dL, urinary protein 9 grams/day

• Serum electrophoresis showed an M spike, urine and serum

immunofixation showed IgG lambdaimmunofixation showed IgG lambda

• Renal biopsy done to find the cause of nephrotic syndrome

PAS negative mesangial nodules

Congo red positive

Lambda Lambda

Kappa Kappa

Kidney, needle biopsy:

AL Amyloidosis,

lambda light chain

type, involving

glomeruli, interstitium

and vessels

8.2 nm in thickness

• Kidney, needle biopsy: AL Amyloidosis, lambda light chain type, involving glomeruli, interstitium and

vessels

– Over 95-98% of patients with systemic AL/AH amyloidosis will have a

detectable M protein on serum or urine protein immunofixation, or an

abnormal serum free light chain ratio. In the small percentage of abnormal serum free light chain ratio. In the small percentage of

patients in whom evidence of a monoclonal process is not apparent on

these studies, a bone marrow biopsy will show evidence of clonal

plasma cells.

Patient # 4

• Mr. SS is a 66 year old man who has a past medical history of urinary abnormalities characterized by nephrotic range proteinuria, microscopic hematuria, and hypertension.

• He now presents with generalized edema, proteinuria of 6.7 gms/24 hours. Urinary sediment shows numerous RBC’s, hyaline and waxy casts. Serum creatinine 1.4 mg/dl. Serologies hyaline and waxy casts. Serum creatinine 1.4 mg/dl. Serologies for ANA, hepatitis, cryo’s are negative. Low C3 and C4 levels.

Clinical Syndrome: �ephrotic/nephritic syndrome

• Renal Biopsy was done

C3

Proliferative GN due to monoclonal Ig deposition

(PGNMID): IgM kappa

Proliferative GN due to monoclonal IgG kappa

deposition (PGNMID)

C3IgG C3

kappa lambda

IgG

58-year old man with nephrotic syndrome, hypertension, hyperlipidemia and edema.

Serum creatinine 1.6 mg/dL, UA- large amounts of blood, Urine IFE kappa light chains

IgG subtyping- IgG3

Low grade B cell

lymphoma

Lymphoplasmacytic/

Waldenström’’’’s lymphoma

Proliferative GN associated with monoclonal

gammopathy

MGRSMultiple

Myeloma

Chronic lymphocytic leukemia

Hematologic Characteristics of Proliferative Glomerulonephritis

with Monoclonal Immunoglobulin Deposits (PGNMID)

• In cases with monoclonal IgG, subtyping for the IgG isotypes (1-4) is helpful

to confirm the diagnosis by demonstrating gamma subtype restriction.

• IgG3 is the most common subclass: this subclass is most likely to have

undetectable M-protein in serum and urine

• Only 20-30% of patients with PGNMID have a detectable M-protein in • Only 20-30% of patients with PGNMID have a detectable M-protein in

serum or urine, mostly IgG1 or IgG2 subclass, but associated hematologic

malignancy is extremely rare.

• The circulating pathologic MIg was most commonly detected on serum

immunofixation (20%; SIFE+) and by abnormal serum free light chain ratio

(19%; sFLCR+).

• Negative SIFE and sFLCR had a 100% negative predictive value for

detectable BM clone.

Progression of Renal Disease and Treatment Outcomes in

PGNMID

•At 1 year point, 40% had ESRD or

doubling of creatinine.

•No relationship was observed between

renal survival and detectability of

pathologic Ig or clone, Ig isotype, IgG

subtype, light chain, age or gender.

Patient # 5

• 61-year old man with monoclonal gammopathy (IgG kappa

protein with M spikes, 0.5-0.9 g/dL), low complement titers

(low C3, normal C4), and gross hematuria, few RBC casts.

Serum creatinine 1.3 mg/dL

• Bone marrow 8% plasma cells: MGUS

• Biopsied in 07 and 09

Mesangial &

Endocapillary

proliferation

Double contours

C3

Mesangial deposits

IgA, IgG, IgM, C1q, kappa and lambda light chains- negative

C3 glomerulonephritis, associated with a

monoclonal gammopathy

Mesangial depositsCapillary wall deposits: subendothelial

and subepithelial deposits

Patient # 6: DDD associated with a monoclonal

gammopathy• 58-year old woman presented with hypertension and chronic kidney disease.

• Serum creatinine 3.45 mg/dL, low C3 and normal C4 level, urinalysis showed 3+ RBC and 3+ protein, UA-25 RBC/HPF

• On dialysis, Work up showed a monoclonal gammopathy of 0.4 mg/dL (IgG kappa)

C3

All Ig’s are negative

C3 glomerulonephritis and MGUS: 32 Mayo Clinic patients :10 (31%) had evidence

of monoclonal Ig. American Journal of Kidney Diseases, 2013

DDD and MGUS: 71.4% of patients 49

years and older in whom DDD was

diagnosed on kidney biopsy also carried an

established diagnosis of MGUS,

American Journal of Kidney Diseases,

2010

Ravindran A, Fervenza F, Smith R, Sethi S

In press

Mechanism of action in C3 glomerulopathy

• Monoclonal Ig may inhibit regulation of the AP of complement by

acting as C3 nephritic factor or by interfering with the function of

complement regulatory proteins such as factor H

• Unique subset of C3G-MIg patients:

– Older patients of C3G– Older patients of C3G

– Presence of autoantibodies: C3Nef was detected in 45.8%

patients

– Pathogenic variants in complement protein genes were rare.

– MIg-targeted treatment may result in remission and stabilization

of the kidney function in a subset of these patients.

Renal and Hematological outcomes of C3G

patients with MIg-targeted therapy

X

Proliferative Glomerulonephritis

IF: Monotypic Ig deposits, with or

without C3

IF: C3 deposits,

absence of monotypic Ig deposits

Indirect mechanismDirect mechanism

DDD or C3GN

Positive for

circulating

monoclonal Ig

Negative for

circulating

monoclonal Ig

Positive for

circulating

monoclonal Ig

Kidney biopsy report• Cast nephropathy (myeloma kidney), (no designation of the

hematologic disease required because this diagnosis is MM-defining)

• AL-amyloidosis, multiple myeloma-associated

• AL-amyloidosis, plasmacytoma-associated

• AL-amyloidosis, B-cell lymphoma-associated

• Light chain deposition disease, smoldering multiple myeloma-

associated

• Light chain deposition disease, B-cell lymphoma-associated

• Light chain deposition disease, MGRS-associated

• Cryoglobulinemic glomerulonephritis, Waldenström

macroglobulinemia-associated

• Cryoglobulinemic glomerulonephritis, chronic lymphocytic leukemia-

associated

• C3-glomerulonephritis, MGRS-associated

• Crystal storing histiocytosis, B-cell lymphoma-associated

• Light chain proximal tubulopathy, MGRS-associated

• Immunotactoid glomerulopathy, lymphoplasmacytic lymphoma-

associated

• Proliferative glomerulonephritis with MIg deposits, MGRS-associated

• Thrombotic microangiopathy, MGRS-associated

• Proliferative glomerulonephritis with MIg deposits, with no

demonstrable serum/urine MIg

• Light chain deposition disease, hematological evaluation pending

The Complexity and Heterogeneity of Monoclonal Immunoglobulin

(MIg)-Associated Renal Diseases

• The triggering hematologic disease may be a malignant condition such

as MM or B cell lymphoproliferative disorder, or a non/pre-malignant

disorder such as MGRS

• Patients may present with acute renal failure, rapidly progressive

glomerulonephritis, nephritic or nephrotic syndrome, or slowly

progressive renal failure depending on the type and severity of the MIg-

associated renal disease

• The underlying pathology is variable and dictates the disease type

• In a small number of cases, the kidney biopsy may demonstrate the MIg,

yet the MIg is not detected in blood or urine and there is no evidence of

a plasma cell or B-cell lymphoproliferative disorder by current standard

testing techniques

The Complexity and Heterogeneity of Monoclonal

Immunoglobulin (MIg)-Associated Renal Diseases

• Most of the diseases are due to tissue deposition of the MIg

deposition (direct mechanism) while in others the MIg does not

deposit but causes injury via other mechanisms such as

dysregulation of the alternative pathway of complement deposition

(indirect mechanism)

• In some diseases the MIg is the sole etiology (as for cast

nephropathy, MIDD) whereas in others it is one of many possible

etiologies (as for C3 glomerulopathy)

• Finally treatment and prognosis vary depending on the type of renal

disorder and the underlying hematologic condition.

Summary

• Close interaction between the nephrologist,

pathologist and hematologist-oncologist is

essential for diagnosis and management of MIg

associated- renal disease

• MIG in the setting of kidney transplant- even

more important, recurrent disease

(next time)

New techniques detection of MIg

• Laser microdissection and mass

spectrometry

• Immunofluorescence studies following • Immunofluorescence studies following

pronase digestion of paraffin embedded

material

Laser micro dissection and mass spectrometry

Microdissection

Trypsin

digestion

Tandem MS/MSHPLC ESI Tandem MS/MSHPLC ESI

Data analysis

Diagnosis and typing of amyloidosis

Diagnostic Criteria

-Apolipoprotein E

-Serum amyloid P component

-Amyloidogenic protein

Patient x

• Mr. JS is a 77-year-old man of Eastern European descent presented with proteinuria

and severe renal insufficiency 6 months ago.

• The patient had numerous co-morbidities which included chronic obstructive

pulmonary disease, bronchiectasis, coronary artery disease, mild aortic stenosis,

arterial hypertension and dyslipidemia.

• Serum creatinine level was 2.2 mg/dL (194 µmol/L) with an estimated glomerular

filtration rate of 29 mL/min.

• Further evaluation showed nephrotic range proteinuria of 5.3 g/day. Microscopic

examination of the urine revealed greater than 100 red blood cells/high power field

• SPEP showed no M-spike on initial evaluation.

• However, the serum IFE revealed a monoclonal lambda band.

• Serum lambda free light chain level was elevated at 2303 mg/L with a kappa/lambda ratio of 0.02. A 24-hour urine collection revealed the presence of a monoclonal lambda light chain.

• Bone studies did not demonstrate any lytic bone lesion.

• A bone marrow biopsy was performed showing a normal cellularity, with a mild monoclonal plasmacytosis (5%)= MGUS, and a negative Congo red stain.

Based on LM and IF- what is your diagnosis so far?

Diagnosis: MIDD?

Kidney biopsy diagnosis: IgD heavy chain deposition disease.

IgD stain- immunoperoxidase

Control diabetic nodule Bone marrow

Immunofluorescence studies

following pronase digestion of

paraffin embedded material

Patient Y• A 67-year-old Caucasian woman status post living-

related kidney transplant was referred September 2015 to Mayo Clinic for evaluation of declining kidney allograft function.

• The patient had initially presented in September 2000 with a creatinine of 2 mg/dl and proteinuria of 1.3 with a creatinine of 2 mg/dl and proteinuria of 1.3 g/24h.

• A kidney biopsy showed mild arterial sclerosis, mild focal global glomerulosclerosis, and mild tubular atrophy and interstitial fibrosis associated with arterial sclerosis

• Serum complement levels were normal, and anti-neutrophil cytoplasmic antibodies, anti-nuclear antibody, and hepatitis B and C serologies were negative.

• At the time a monoclonal kappa light chain was detected in the urine on immunofixation studies. Additional past medical history included hypertension, hyperlipidemia, obstructive sleep apnea and nicotine dependence.

• No bone marrow biopsy was performed and she was considered to MGUS and was treated conservatively.considered to MGUS and was treated conservatively.

• Periodic evaluations of the monoclonal gammopathy showed no progression of her MGUS. In November 2012, the serum creatinine was 3.2 mg/dl

lambda IF following pronase digestion

kappa

lambda

kappa

Diagnosis

• De novo light chain proximal

tubulopathy in an allograft kidney

• Laboratory evaluation of kappa free light chains (FLC) in the serum showed elevated values between 50-60 mg/dl (normal range 0.33-1.94) and lambda FLC were normal.

• A bone marrow biopsy after the allograft kidney biopsy showed features of multiple myeloma with 5-10% of plasma cells that were positive for monotypic kappa light chains. monotypic kappa light chains.

• Congo red stain was negative. Imaging studies did not show any evidence of lytic lesions.

• She received four cycles of bortezomib and dexamethasone resulting in decline of kappa FLC to 3.8 mg/dl, consistent with a very good partial response. Since then, kappa light chains level have remained stable.

• The kidney function also improved with sCr decreasing progressively to 1.2 mg/dL, which are consistent with her baseline values.

• At the last follow-up, her kidney function remained stable (sCr 1.2 mg/dl, clearance 40 ml/min) and kappa FLC were 6.4 mg/dl.

Old native biopsy from 2000

lambda

kappa

Diagnosis: Light chain proximal tubulopathy,

recurrent

Light chain proximal tubulopathy

kappalambda

Light chain proximal tubulopathy• LCPT is characterized by cytoplasmic inclusions of monoclonal light chains

(more commonly kappa than lambda) within proximal tubular cells

• The inclusions can be crystalline (more common) or non-crystalline

• Kappa light chains of the Vk1 subgroup are the most pathogenic because

they introduce hydrophobic side chains on the variable domain that inhibit

proteolysis and facilitate crystallizationproteolysis and facilitate crystallization

• The non-crystalline LCPT is still poorly defined and requires differentiation

from physiologic tubular reabsorption: A helpful diagnostic feature of both

crystalline and non-crystalline LCPT is the presence of acute tubular injury

• Pronase IF technique very helpful

• LCPT was associated with a MGRS in 46% (of which 4% converted to MM),

MM in 33%, SMM in 15%, non-Hodgkin’s lymphoma in 4% and CLL in 2%

of the patients

Thank you