Pathology of the kidney in Waldenström's macroglobulinemia. Study of sixteen cases

Hematological Malignancies and the Kidney

The incidence of hematologic malignancies is on the rise worldwide. Kidney disease is ubiquitous in patients with hematologic malignancies, encompassing a wide spectrum of disorders involving each kidney compartment, including the vasculature, tubules, interstitium, and glomerulus, and there is significant overlap of kidney involvement with each hematologic malignancy. Vascular disorders include both microvascular and macrovascular damage, via thrombotic microangiopathy, hyperleukocytosis, hyperviscosity, and cryoglobulinemia. The tubulointerstitial compartment may be affected by prerenal azotemia and acute tubular injury, but malignant infiltration, tumor lysis syndrome, extramedullary hematopoiesis, cast nephropathy, granulomatous interstitial nephritis, and lysozymuria should be considered in certain populations. Obstructive uropathy may occur due to nephrolithiasis or retroperitoneal fibrosis. Glomerular disorders, including membranoproliferative, membranous, minimal change, and focal segmental glomerulosclerosis, can rarely occur. By understanding how each compartment may be affected, care can best be optimized for these patients. In this review, we summarize the widely varied etiologies of kidney diseases stratified by kidney compartment and hematologic malignancy, focusing on demographics, pathology, pathophysiology, mechanism, and outcomes. We conclude with common electrolyte abnormalities associated with hematologic malignancies.

Focal Segmental Glomerulosclerosis in Waldenström's Macroglobulinemia

Renal involvement in Waldenström's macroglobulinemia is a rare manifestation. Although most renal involvement is due to monoclonal immune deposits, pathology can also be unrelated to it. Here, we describe a 68-year-old female with a history of Waldenström's macroglobulinemia who presented with generalized edema and nephrotic range proteinuria. A renal biopsy showed findings consistent with focal segmental glomerulosclerosis. Treatment with oral prednisone leads to the resolution of proteinuria. This case highlights the importance of identifying pathology that might not be directly related to monoclonal gammopathy, which could have implications on the management.

Pseudothrombus deposition accompanied with minimal change nephrotic syndrome and chronic kidney disease in a patient with Waldenström's macroglobulinemia: A case report

BACKGROUND

Waldenström's macroglobulinemia (WM) is a rare lymphoid neoplasia, which can have renal complications. These rarely occur, and most common renal manifestations are mild proteinuria and microscopic hematuria. Herein we describe a case of WM that presented with pseudothrombi depositing in capillaries associated with minimal change nephrotic syndrome and chronic kidney disease (CKD).

CASE SUMMARY

A 52-year-old man presented with features suggesting nephrotic syndrome. Extensive workups were done, and there were elevated serum levels of interleukin-6 and vascular endothelial growth factor (VEGF), capillary pseudothrombus accumulation associated with minimal change nephrotic syndrome, CKD, and WM. Treatment was directed at the patient's WM with bortezomib, thalidomide, and dexamethasone whereby serum immunoglobulin M (IgM) decreased. The damage of IgM on the kidney was corrected; thus, the patient's proteinuria and serum creatinine had improved. The patient is still under clinical follow-up.

CONCLUSION

It is essential for clinicians to promptly pay more attention to patients presenting with features of nephrotic syndrome and do extensive workups to come up with a proper therapy strategy.

Clinicopathological spectrum of renal parenchymal involvement in B-cell lymphoproliferative disorders

The clinicopathological characteristics of kidney infiltration in B-cell lymphoproliferative disorders remain poorly described. We retrospectively studied 52 adults with biopsy-proven malignant B-cell kidney infiltration, including Waldenström's macroglobulinemia (n=21), chronic lymphocytic leukemia (n=11), diffuse large B-cell lymphoma (DLBCL) (n=8), other lymphoma (n=11), and multiple myeloma (n=1). Kidney disease varied according to the underlying lymphoproliferative disorder. In DLBCL, malignant kidney infiltration was prominent, resulting in acute kidney injury (AKI, 75%) and kidney enlargement (88%). In the other types, associated immunoglobulin-related nephropathy (most commonly AL amyloidosis) was more common (45%), and chronic kidney disease with proteinuria was the primary presentation. All patients received chemotherapy. Over a median follow-up of 31 months, 20 patients died and 21 reached end-stage kidney disease. Renal response, achieved in 25 patients (48%), was associated with higher overall survival (97 vs. 37 months in non-renal responders). In univariate analysis, percentage of sclerotic glomeruli, kidney enlargement, and complete hematological response at 6 months were predictive of renal response. In multivariate analysis, concomitant immunoglobulin-related nephropathy was the sole independent predictor of poor renal outcome. In conclusion, clinical presentation of renal lymphomatous infiltration depends on the nature of the underlying lymphoproliferative disorder. In DLBCL, massive renal infiltration manifests with enlarged kidneys and AKI, and the diagnosis primarily relies on lymph node biopsy. In other B-cell lymphoproliferative disorders, the clinicopathological spectrum is more heterogeneous, with a high frequency of immunoglobulin-related nephropathy that may affect renal outcome; thus kidney biopsy is required for early diagnosis and prognostic assessment.

Kidney diseases associated with Waldenström macroglobulinemia

Waldenström macroglobulinemia (WM) is a rare B-cell lymphoma characterized by lymphoplasmacytic cell infiltration in the bone marrow and other organs and the presence of a monoclonal immunoglobulin M protein in the serum. Although uncommon, several kidney diseases have been associated with WM. In addition to kidney diseases related to lymphoplasmacytic lymphoma infiltration, a variety of glomerular and tubular lesions have been described in patients with WM. Immunoglobulin light chain (AL) amyloidosis and cryoglobulinemic glomerulonephritis are the two predominant glomerular pathologies seen in WM. In this article we review the kidney diseases associated with WM. We also briefly review some nephrotoxicities of novel chemotherapeutic and targeted therapies used for the treatment of WM.

Thrombotic microangiopathy with intraglomerular IgM pseudothrombi in Waldenström macroglobulinemia and IgM monoclonal gammopathy

IgM secreting myelomas or lymphomas, including Waldenström macroglobulinemia, are associated with a varied spectrum of renal pathology, including intracapillary hyaline deposits, cryoglobulin, membranoproliferative glomerulonephritis, amyloid, monoclonal immunoglobulin deposition disease, cast nephropathy, and lymphoma infiltration. We report our single institution experience, and describe five cases with distinctive glomerular pathology: intracapillary IgM pseudothrombi and thrombotic microangiopathic change, with glomerular intracellular crystals in two biopsies. Two patients were hypocomplementemic at presentation. This series adds to the recent literature on paraprotein associated thrombotic microangiopathy.

Kidney Involvement of Patients with Waldenström Macroglobulinemia and Other IgM-Producing B Cell Lymphoproliferative Disorders

BACKGROUND AND OBJECTIVES

Kidney involvement in Waldenström macroglobulinemia is less well described compared with kidney manifestations in multiple myeloma.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Of the 1363 patients seen with Waldenström macroglobulinemia and other IgM-secreting B cell lymphoproliferative disorders seen at the Mayo Clinic between 1996 and 2015, 57 kidney biopsies were retrospectively studied. The biopsy findings were correlated with clinical, kidney, and hematologic characteristics. Criteria for inclusion were evidence of a monoclonal IgM protein and availability of a kidney and a bone marrow biopsy for review. Glomerular and tubulointerstitial pathologies were categorized according to whether they were related to the monoclonal IgM.

RESULTS

Of the 57 patients identified, monoclonal gammopathy-related kidney lesions were identified in 82% (47 of 57 biopsies), whereas nonmonoclonal gammopathy-related kidney lesions were seen in 18% (ten of 57). Monoclonal gammopathy-related kidney lesions included monoclonal Ig-related amyloidosis (n=19; 33%), nonamyloid glomerulopathy (n=20, 35%), and tubulointerstitial nephropathies (n=8; 14%). The most common monoclonal gammopathy-related kidney lesion was monoclonal Ig-related amyloidosis (n=19; 33%) followed by cryoglobulinemic GN (n=13; 28%). Lymphoma infiltration was the most common tubulointerstitial lesion (n=4; 9%). The hematologic diagnosis was Waldenström macroglobulinemia in 74% (n=42), monoclonal gammopathy of renal significance in 16% (n=9), and marginal zone lymphoma (n=2), chronic lymphocytic leukemia (n=2), and low-grade B cell lymphoma (n=2) in 4% each.

CONCLUSIONS

Our study confirms a diverse variety of kidney lesions in patients with monoclonal IgM gammopathy.

Dysproteinemias and Glomerular Disease

Dysproteinemia is characterized by the overproduction of an Ig by clonal expansion of cells from the B cell lineage. The resultant monoclonal protein can be composed of the entire Ig or its components. Monoclonal proteins are increasingly recognized as a contributor to kidney disease. They can cause injury in all areas of the kidney, including the glomerular, tubular, and vascular compartments. In the glomerulus, the major mechanism of injury is deposition. Examples of this include Ig amyloidosis, monoclonal Ig deposition disease, immunotactoid glomerulopathy, and cryoglobulinemic GN specifically from types 1 and 2 cryoglobulins. Mechanisms that do not involve Ig deposition include the activation of the complement system, which causes complement deposition in C3 glomerulopathy, and cytokines/growth factors as seen in thrombotic microangiopathy and precipitation, which is involved with cryoglobulinemia. It is important to recognize that nephrotoxic monoclonal proteins can be produced by clones from any of the B cell lineages and that a malignant state is not required for the development of kidney disease. The nephrotoxic clones that do not meet requirement for a malignant condition are now called monoclonal gammopathy of renal significance. Whether it is a malignancy or monoclonal gammopathy of renal significance, preservation of renal function requires substantial reduction of the monoclonal protein. With better understanding of the pathogenesis, clone-directed strategies, such as rituximab against CD20 expressing B cell and bortezomib against plasma cell clones, have been used in the treatment of these diseases. These clone-directed therapies been found to be more effective than immunosuppressive regimens used in nonmonoclonal protein-related kidney diseases.

Waldenström's Macroglobulinemia Associated With Generalized AA-Amyloidosis

The authors present a case of Waldenström's macroglobulinemia (WM) associated with generalized amyloidosis of amyloid-A type. A 77-year-old man with a 25-year history of degenerative joint disease and a 13-year history of WM died of multisystemic failure. At autopsy, generalized and severe amyloid deposits were detected. Special conventional stains and immunohistochemical examination revealed amyloid-A de posits, which are extinguishingly rare in WM. This is probably related to the disease being chronic, which results in excessive production of precursor protein. The detection of amyloid-A type fibrils was possible only through the application of the immunohis tochemical procedure. The authors emphasize using the immunohistochemical typing of amyloid deposits for the purpose of classification, therapy, and prognosis. Int J Surg Pathol 1 (2):123-128, 1993

Simultaneous occurrence of fibrillary glomerulonephritis and renal lesions in nonmalignant monoclonal IgM gammopathy

BACKGROUND

Fibrillary glomerulonephritis (FGN) is a rare primary glomerular disease that seldom coexists with other diseases. Membranoproliferative glomerulonephritis is a pathologic finding of renal lesions associated with IgM-secreting monoclonal proliferations. We present a case study of a patient with unusual simultaneous FGN and IgM-related renal disorder in nonmalignant monoclonal IgM gammopathy.

CASE PRESENTATION

A 63-year-old male presented with nephrotic syndrome and elevated serum creatinine levels. Laboratory examination revealed elevated levels of serum IgM and low C3 levels. Serum and urine immunofixation electrophoresis showed a monoclonal IgM with a kappa light chain. A bone marrow biopsy revealed less than 5 % bone marrow infiltration by lymphoplasmacytic lymphoma, and a renal biopsy revealed mesangiocapillary glomerulonephritis on light microscopy. Immunofluorescent and immunohistochemical staining indicated granular deposits of immunoglobulin G in the mesangium and granular deposits of immunoglobulin M and κ light chains along the capillary wall. Electron microscopy revealed randomly arranged nonbranching fibrils of approximately 15 nm in diameter in the glomerular mesangium and subendothelial electron-dense deposits. According to these results, we confirmed FGN and membranoproliferative glomerulonephritis, which were attributed to monoclonal IgM deposits.

CONCLUSION

To the best of our knowledge, this is the first report of simultaneous FGN and membranoproliferative glomerulonephritis in nonmalignant IgM monoclonal gammopathy.

Cast nephropathy: an extremely rare renal presentation of Waldenström's macroglobulinaemia

Renal involvement in Waldenström's macroglobulinaemia (WM) is very unusual when compared to multiple myeloma. We report a case of a patient who developed anuric acute kidney injury secondary to cast nephropathy, dependent on high-flux haemodialysis. Complementary study revealed the presence of blood IgM monoclonal gammopathy and a massive bone marrow lymphoplasmacytic infiltration. There were no osteolytic lesions and no clinical signs/symptoms of hyperviscosity syndrome. The diagnosis of WM was established and a dexamethasone plus cyclophosphamide regime was started, in addition to plasmapheresis. The patient partially recovered renal function allowing haemodialysis and plasmapheresis withdrawal. He remained asymptomatic with a good response to chemotherapy and 12 months after his renal function remained stable. This is a rare clinical case in which WM presented as an IgM cast nephropathy, which in turn is an extremely rare renal presentation of this equally rare haematological disorder.

Kidney diseases associated with monoclonal immunoglobulin M-secreting B-cell lymphoproliferative disorders: a case series of 35 patients

BACKGROUND

Kidney diseases associated with immunoglobulin M (IgM) monoclonal gammopathy are poorly described, with few data for patient outcomes and renal response.

STUDY DESIGN

Case series.

SETTING & PARTICIPANTS

35 patients from 8 French departments of nephrology were retrospectively studied. Inclusion criteria were: (1) detectable serum monoclonal IgM, (2) estimated glomerular filtration rate (eGFR) < 60mL/min/1.73m(2) and/or proteinuria with protein excretion > 0.5g/d and/or microscopic hematuria, and (3) kidney biopsy showing monoclonal immunoglobulin deposits and/or lymphomatous B-cell renal infiltration. All patients received chemotherapy, including rituximab-based regimens in 8 cases.

PREDICTORS

Patients were classified into 3 groups according to renal pathology: glomerular AL amyloidosis (group 1; n=11), nonamyloid glomerulopathies (group 2; n=15, including 9 patients with membranoproliferative glomerulonephritis), and tubulointerstitial nephropathies (group 3; n=9, including cast nephropathy in 5, light-chain Fanconi syndrome in 3, and isolated tumor infiltration in 1).

OUTCOMES

Posttreatment hematologic response (≥50% reduction in serum monoclonal IgM and/or free light chain level) and renal response (≥50% reduction in 24-hour proteinuria or eGFR≥30mL/min/1.73m(2) in patients with glomerular and tubulointerstitial disorders, respectively).

RESULTS

Nephrotic syndrome was observed in 11 and 6 patients in groups 1 and 2, respectively. Patients in group 3 presented with acute kidney injury (n=7) and/or proximal tubular dysfunction (n=3). Waldenström macroglobulinemia was present in 26 patients (8, 12, and 6 in groups 1, 2, and 3, respectively). Significant lymphomatous interstitial infiltration was observed in 18 patients (4, 9, and 5 patients, respectively). Only 9 of 29 evaluable patients had systemic signs of symptomatic hematologic disease (2, 5, and 2, respectively). In groups 1, 2, and 3, respectively, hematologic response was achieved after first-line treatment in 3 of 9, 9 of 10, and 5 of 6 evaluable patients, while renal response occurred in 5 of 10, 9 of 15, and 5 of 8 evaluable patients.

LIMITATIONS

Retrospective study; insufficient population to establish the impact of chemotherapy.

CONCLUSIONS

IgM monoclonal gammopathy is associated with a wide spectrum of renal manifestations, with an under-recognized frequency of tubulointerstitial disorders.

Diagnosis of monoclonal gammopathy of renal significance

Monoclonal gammopathy of renal significance (MGRS) regroups all renal disorders caused by a monoclonal immunoglobulin (MIg) secreted by a nonmalignant B-cell clone. By definition, patients with MGRS do not meet the criteria for overt multiple myeloma/B-cell proliferation, and the hematologic disorder is generally consistent with monoclonal gammopathy of undetermined significance (MGUS). However, MGRS is associated with high morbidity due to the severity of renal and sometimes systemic lesions induced by the MIg. Early recognition is crucial, as suppression of MIg secretion by chemotherapy often improves outcomes. The spectrum of renal diseases in MGRS is wide, including old entities such as AL amyloidosis and newly described lesions, particularly proliferative glomerulonephritis with monoclonal Ig deposits and C3 glomerulopathy with monoclonal gammopathy. Kidney biopsy is indicated in most cases to determine the exact lesion associated with MGRS and evaluate its severity. Diagnosis requires integration of morphologic alterations by light microscopy, immunofluorescence (IF), electron microscopy, and in some cases by IF staining for Ig isotypes, immunoelectron microscopy, and proteomic analysis. Complete hematologic workup with serum and urine protein electrophoresis, immunofixation, and serum-free light-chain assay is required. This review addresses the pathologic and clinical features of MGRS lesions, indications of renal biopsy, and a proposed algorithm for the hematologic workup.

Waldenström's macroglobulinemia - a review

Waldenström's macroglobulinemia (WM) is a lymphoproliferative disease of B lymphocytes, characterized by a lymphoplasmocytic lymphoma in the bone marrow and by IgM monoclonal hypergammaglobulinemia. It was first described in 1944 by Jan Gösta Waldenström, reporting two patients with oronasal bleeding, lymphadenopathy, anemia, thrombocytopenia, high erythrocyte sedimentation rate and serum viscosity, normal radiography and bone marrow infiltrated by lymphoid cells. The WM is a rare disease with a typically indolent clinical course, affecting mainly individuals aged between 63 and 68 years. Most patients have clinical signs and symptoms related to hyperviscosity resulting from IgM monoclonal gammopathy, and/or cytopenias resulting from bone marrow infiltration by lymphoma. The differential diagnosis with other lymphomas is essential for the assessment of prognosis and therapeutic approach. Treatment of patients with asymptomatic WM does not improve the quality of life of patients, or increase their survival, being recommended, therefore, their follow-up. For the treatment of symptomatic patients, alkylating agents, purine analogs and anti-CD20 monoclonal antibodies are used. However, the disease is incurable and the response to therapy is not always favorable. Recent studies have shown promising results with bortezomib, an inhibitor of proteasomes, and some patients respond to thalidomide. In patients with relapse or refractory to therapy, autologous transplantation may be indicated. The aim of this paper is to describe in detail the current knowledge on the pathophysiology of WM, main clinical manifestations, diagnosis, prognosis and treatment.

Proliferative glomerulonephritis with monoclonal IgM-κ deposits in chronic lymphocytic leukemia/small lymphocytic leukemia: case report and review of the literature

A 48-year-old man with chronic lymphocytic leukemia presented with nephrotic syndrome, hematuria, and mild deterioration of renal function. Further analysis using serum immunofixation electrophoresis detected monoclonal immunoglobulin (Ig) M-κ and IgG-κ M-protein. Testing for cryoglobulin in serum was negative. Light microscopy of a renal biopsy specimen showed membranoproliferative glomerulonephritis features with marked mononuclear cell infiltration in the interstitium. On immunofluorescence study, the deposition of IgM heavy chain was predominantly observed with the same distribution of κ light chain, whereas no λ light chain was found. Electron microscopy revealed fine granular deposits in the mesangial, subendothelial, and subepithelial areas, mimicking those observed in the immune complex-mediated glomerulonephritis. These pathological findings were consistent with recently described cases of proliferative glomerulonephritis with monoclonal IgG deposits. Thus, monoclonal IgM deposition can also cause proliferative glomerulonephritis.

A Case of Nephrotic Syndrome With Minimal-Change Disease and Waldenstrom's Macroglobulinemia

Kidney disease is a rare complication of Waldenstrom’s macroglobulinemia. We report a case of nephrotic syndrome and minimal change disease in a patient with biopsy proven Waldenstrom’s macroglobulinemia. The patient presented with over 12 grams of proteinuria and was successfully treated with oral prednisone over the course of 4 weeks. Repeat serum protein electrophoresis as well as serum immunoelectrophoresis revealed no paraproteins, urine analysis was negative for protein or blood by dipstick and spot urine protein was 9 mg/dL with creatinine of 101 mg/dL at time of last office visit. This case illustrates the successful treatment with corticosteroids alone with prolonged complete remission.

Membranoproliferative glomerulonephritis complicating Waldenström's macroglobulinemia

Background

Lymphoproliferative disorders causing paraproteinemia can be associated with various kidney injuries including the deposition of monoclonal immunoglobulins (Ig). A known glomerular manifestation of Waldenström’s macroglobulinemia is characterized by prominent intracapillary hyaline thrombi and lack of conspicuous glomerular proliferation. The present case was special in 2 aspects: 1. the diagnosis of glomerulonephritis was unexpected before renal biopsy, 2. the prominent glomerular proliferation paired with large intracapillary hyaline thrombi is uncommon in Waldenström’s macroglobulinemia-associated glomerulonephritis.

Case presentation

A 73-year-old Caucasian woman with a long-standing history of rheumatoid arthritis and Waldenström’s macroglobulinemia was admitted for acute renal failure (ARF), which initially was presumed to be the consequence of extrarenal causes. Proteinuria and hematuria were only mild. In renal core biopsy, a membranoproliferative glomerulonephritis (MPGN) and prominent intracapillary hyaline monoclonal IgM thrombi were found in addition to acute tubular necrosis. Of note, the patient’s history was positive for purpuric skin changes, suspicious for cryoglobulinemia. However, serological tests for cryoglobulins were repeatedly negative. The ARF resolved before the start of immunomodulatory therapy for Waldenström’s macroglobulinemia.

Conclusion

The presence of MPGN with prominent hyaline thrombi in the context of Waldenström’s macroglobulinemia is uncommon and can be oligosymptomatic. We discuss this case in the context of previous literature and classifications suggested for monoclonal Ig-related renal pathologies.

Discrete renal deposition of IgM heavy chain and κ light chain in Waldenström macroglobulinemia (IgM-κ)

We report previously undescribed renal lesions associated with monoclonal gammopathy in a 59-year-old man with Waldenström macroglobulinemia (IgM-κ). Light microscopy showed mesangial proliferation and thickening of glomerular basement membranes (GBMs) and tubular basement membranes (TBMs). Neither intraglomerular thrombi nor nodular glomerulosclerosis was observed. Immunofluorescence studies disclosed essentially discrete localization of IgM heavy chain within the mesangial area and κ light chain along GBMs and TBMs. Electron microscopy showed continuous linear deposits of finely granular electron-dense material along the inner aspect of GBMs and TBMs. Repeated rituximab treatment and chemotherapy (melphalan and prednisolone) led to the improvement of proteinuria.

Cast nephropathy and light-chain deposition disease in Waldenström macroglobulinemia

Waldenström macroglobulinemia is a rare low-grade hematologic malignancy due to clonal proliferation of B lymphocytes responsible for immunoglobulin M (IgM) monoclonal gammopathy secreted in serum. This disease is characterized by lymphoplasmacytic tumoral infiltration of bone marrow and various organs, especially the liver and spleen. Kidney involvement in Waldenström macroglobulinemia has been described previously with reports of various forms of glomerular injury: large intracapillary IgM pseudothrombi, cryoglobulinemia-associated membranoproliferative glomerulonephritis, or amyloidosis. Interstitial infiltration by tumoral B lymphocytes is another classic pattern. Conversely, tubular involvement in the form of myeloma-like casts or basement membrane deposition of monoclonal light chain (light-chain deposition disease) is unusual. We report the occurrence of cast nephropathy associated with light-chain deposition disease in 2 patients with Waldenström macroglobulinemia, which resulted in severe and prolonged kidney failure.

Therapeutic apheresis for renal disorders

This review summarizes the clinical evidence and practical details for the use of plasmapheresis and other apheresis modalities for each indication in nephrology. Updated information on the molecular biology and immunology of each renal disease is discussed in relation to the rationale for apheresis therapy and its place amid other available treatments. Autoantibody-mediated diseases, such as anti-GBM (anti-glomerular basement membrane) glomerulonephritis (GN), ANCA (antineutrophil cytoplasmic antibody)-related GN and the antibody-mediated type of TTP (thrombotic thrombocytopenic purpura), and alloantibody-mediated diseases such as kidney transplant sensitization and humoral rejection, can be treated by various plasmapheresis methods. These include standard plasmapheresis with a replacement volume, or plasmapheresis with online plasma purification using adsorption columns or secondary filtration. However, it should be noted that the pathogenic molecules implicated in FSGS (focal segmental glomerulosclerosis), myeloma cast nephropathy, and perhaps other diseases are too small to be removed by most online purification methods. A great majority of controlled trials and series on which evidence-based treatment recommendations are made were performed using centrifugal plasmapheresis; it is presumed that membrane-separation plasmapheresis is equally efficacious. For some rarer diseases, such as MPGN (membranoproliferative GN) type 2 with factor H abnormalities or C3Nef (C3 nephritic factor) autoantibodies, there are only a few case reports, but enough scientific understanding to warrant a trial of plasmapheresis in severe cases. Photopheresis, which is effective for cell-mediated rejection in heart and lung transplantation, has not yet found a place in the routine treatment of kidney transplant rejection.

Development of Renal Failure without Proteinuria in a Patient with Monoclonal Gammopathy of Undetermined Significance: An Unusual Presentation of AL Kappa Amyloidosis

AL amyloidosis complicating monoclonal gammopathy of undetermined significance (MGUS) has usually a predominant glomerular deposition of lambda light chain. Heavy proteinuria is one of its cardinal manifestations. A 78-year-old man with a 9-year history of IgG kappa light-chain-MGUS and normal urine protein excretion developed severe renal failure. Serum levels of kappa light chain and serum IgG had been stable while proteinuria was absent throughout the nine-year period. For the first eight years, he had stable stage III chronic kidney disease attributed to bladder outlet obstruction secondary to prostatic malignancy. In the last year, he developed progressive serum creatinine elevation, without any increase in the serum or urine levels of paraproteins or any sign of malignancy. Renal ultrasound and furosemide renogram showed no evidence of urinary obstruction. Renal biopsy revealed AL amyloidosis, with reactivity exclusive for kappa light chains, affecting predominantly the vessels and the interstitium. Glomerular involvement was minimal. Melphalan and prednisone were initiated. However, renal function continues deteriorating. Deposition of AL kappa amyloidosis developing during the course of MGUS predominantly in the wall of the renal vessels and the renal interstitium, while the involvement of the glomeruli is minimal, leads to progressive renal failure and absence of proteinuria. Renal biopsy is required to detect both the presence and the sites of deposition of renal AL kappa light chain amyloidosis.

Recovery of kidney function by rituximab-based therapy in a patient with Waldenström's macroglobulinemia-related nephropathy presenting cast nephropathy and interstitial lymphocytic infiltration

A 60-year-old man with Waldenström's macroglobulinemia (WM) was admitted to our hospital for evaluation of rapid progressive renal deterioration despite 3 cycles of oral melphalan and prednisolone (MP) therapy. Renal biopsy just before introducing hemodialysis revealed cast nephropathy and severe tubulo-interstitial infiltration of B lymphocytes. After 6 cycles of rituximab, cyclophosphamide, vincristine and prednisolone (R-COP) therapy, his renal function improved enough to discontinue hemodialysis. This is a rare case of WM-related renal involvement caused by both monoclonal protein and tumor infiltration and, to our knowledge, the second report on improved renal function by rituximab-based therapy.

Waldenstrom's Macroglobulinemia Presenting as Goodpasture's Syndrome

We report a case of Waldenstrom's macroglobulinemia (WM) presenting as classic Goodpasture's syndrome. Thrombocytopenia, an additional autoimmune phenomenon, further complicated the clinical course. Renal disease is well recognized in Waldenstrom's macroglobulinemia and other B-cell dyscrasias. Similarly, a wide spectrum of autoimmune-mediated conditions has been reported in association with paraproteinemia. However, rapidly progressive glomerulonephritis in association with antiglomerular basement membrane antibodies has never been reported as either an autoimmune or a renal manifestation of WM. This article reviews the current understanding of renal pathology and autoimmune phenomenon associated with WM.

Nephrotic syndrome and kidney failure due to immunocomplex-mediated renal damage in a patient with Waldenström's Macroglobulinemia: a case report

Introduction

Unlike the quite frequent renal involvement seen in cases of Multiple Myeloma, the kidney is hardly ever compromised in patients with Waldenström's Macroglobulinemia. Nephrotic range proteinuria is a very unusual manifestation of renal injury in these patients and when present it is due to amyloid light-chain deposition most of the times.

Case presentation

A 60-year-old male patient presented to the hospital with nephrotic syndrome, renal insufficiency, hypertension and lymphadenopathy. The investigations led to the diagnosis of Waldenström's Macroglobulinemia with associated nephrotic syndrome and chronic kidney disease due to an unusual form of hypocomplementemic glomerulopathy with histopathological features similar to those seen in mesangiocapillary glomerulonephritis type III, but lacking proliferative changes.

Conclusion

We present an unusual case of immunologically-mediated renal damage in a patient with Waldenström's Macroglobulinemia, leading to non-amyloid nephrotic syndrome and chronic renal insufficiency.

Renal lesions associated with IgM-secreting monoclonal proliferations: revisiting the disease spectrum

BACKGROUND AND OBJECTIVES

Since the first description of pathology of the kidney in Waldenström disease in 1970, there have been few reports on kidney complications of IgM-secreting monoclonal proliferations. Here, we aimed to revisit the spectrum of renal lesions occurring in patients with a serum monoclonal IgM.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Fourteen patients with a circulating monoclonal IgM and a kidney disease related to B cell proliferation were identified retrospectively. Demographic, clinical, and laboratory data were assessed for each patient at the time of kidney biopsy.

RESULTS

Seven patients had a nephrotic syndrome. Patients without nephrotic syndrome all had impaired renal function. Mean serum creatinine was 238 micromol/L. For five patients, the diagnosis of monoclonal IgM preceded the kidney disease by 28.8 mo (range 12 to 60). Seven patients had Waldenström disease, two had a small B cell non-Hodgkin lymphoma, one had an IgM-excreting multiple myeloma, one had a marginal zone B cell lymphoma, and three had an IgM-related disorder. Renal lesions included (1) intracapillary monoclonal deposits disease with granular, electron-dense IgM thrombi occluding capillary lumens (5); (2) atypical membranoproliferative glomerulonephritis (3); (3) lambda light chain amyloidosis (2) associated with mu deposits in one patient; (4) acute tubular necrosis (1); and (5) CD20(+) lymphomatous infiltration (3). Remission of the nephrotic syndrome was attained in three of seven patients, and renal function improved after chemotherapy.

CONCLUSIONS

Although renal complications of IgM proliferations are rare, a wide spectrum of kidney lesions is observed, without correlation with the type of hematologic disorder.

Acute renal failure due to IgM-lambda glomerular thrombi and MPGN-like lesions in a patient with angioimmunoblastic T-Cell lymphoma

A 70-year-old man with angioimmunoblastic T-cell lymphoma developed acute renal failure. Laboratory data showed decreased levels of serum C3, C4, and CH50, elevated immunoglobulin M (IgM) levels, and the presence of cryoglobulinemia (IgM-lambda). Renal biopsy showed membranoproliferative glomerulonephritis-like lesions with azan-red-stained thrombi in the glomerular capillary lumen. Immunofluorescence showed that IgM-lambda stained strongly in the glomerular capillary lumen, equal to the azan-red-stained thrombi, whereas C3 and C4 staining was negative. Electron microscopy showed electron-dense deposits in the subendothelial space and glomerular thrombi lacking fine fibrillar structure. These findings suggest that cryoglobulin, which consists of monoclonal IgM-lambda, induced glomerular thrombi and acute renal failure in a patient with angioimmunoblastic T-cell lymphoma.

Waldenström's macroglobulinemia

The diagnosis of Waldenström's macroglobulinemia (WM) requires evidence of bone-marrow infiltration by lymphoplasmacytoid lymphoma and detection of serum monoclonal protein of IgM type. The normal counterpart of the WM malignant cell is believed to be a postgerminal-center B cell. The clinical manifestations and laboratory abnormalities associated with WM are related to direct tumor infiltration and to the amount and specific properties of IgM. Asymptomatic patients should be followed without treatment. When treatment is indicated, the three main choices for systemic frontline treatment are chlorambucil, the nucleoside analogues fludarabine or cladribine and the monoclonal antibody rituximab. There is evidence that high-dose therapy with autologous stem-cell transplantation is effective even in patients with advanced and resistant disease. Patient's age, hemoglobin and serum beta2-microglobulin before treatment are important prognostic variables which correlate with survival.

Fanconi’s syndrome induced by a monoclonal Vκ3 light chain in Waldenström’s macroglobulinemia

Fanconi's syndrome (FS) is a disorder of sodium-dependent proximal tubule reabsorption, which may complicate plasma cell disorders producing a free monoclonal light chain (LC). FS often occurs in the setting of smoldering myeloma and features cytoplasmic crystalline inclusions of monoclonal kappa LC in proximal tubular cells and malignant plasma cells. Although the clinical and pathological presentation may vary, including lack of crystal formation, monoclonal kappa LCs that underlie FS show a striking genetic and biochemical homogeneity: they almost always belong to the Vkappa1 subgroup of variability and originate from 2 germline genes, O2/O12 or O8/O18. Their variable domain sequences present unusual hydrophobic residues, responsible for the resistance to proteolysis, which leads to LC accumulation in the endocytic compartment of proximal tubule cells. We report a patient with slowly progressive Waldenstrom's macroglobulinemia and full-blown FS with accumulation of a monoclonal kappa LC within proximal tubules, but no detectable crystalline organization. This LC, which belonged to the unusual Vkappa3 subgroup and derived from the L2/L16 germline gene, showed no common substitution with previously described FS kappaI LC and was sensitive to trypsin digestion. These data show that molecular and biochemical characteristics of kappa LCs in patients with FS are more heterogeneous than initially suspected. Mechanisms other than resistance of LCs to endosomal proteolysis probably are involved in the pathogenesis of FS-associated plasma cell dyscrasias.

Dysproteinemia and the kidney

Dysproteinemia is a clinical state characterized by abnormal, often excessive, synthesis of immunoglobulin (Ig) molecules or subunits. Dysproteinemia results from clonal proliferation of plasma cells or B lymphocytes. The abnormal circulating Ig molecules or subunits (most commonly free light chains) reach the glomerulus via the systemic circulation and are associated with the development of a variety of pathologic lesions within the kidney. Free light chain molecules may pass through the glomerular basement membrane and form casts within distal tubular lumina (myeloma cast nephropathy) or form crystals within the cytoplasm of proximal tubules (light chain Fanconi syndrome). Alternatively, Ig molecules or subunits may form paraprotein tissue deposits and produce an array of pathologic lesions, most commonly amyloidosis and monoclonal Ig deposition disease. The pattern of renal parenchymal disease is determined by the unique properties of the Ig molecule or subunit. Each of the patterns of renal disease is in turn associated with unique, but frequently overlapping, clinical features and outcomes. This review emphasizes the pathologic, clinical, and prognostic differences among the patterns of renal parenchymal disease related to dysproteinemia.

Waldenstrom's macroglobulinemia: a retrospective analysis of 40 patients from 1972 to 2001

From 1972 to 2001 at St. Bartholomew's Hospital 40 untreated Waldenstrom's macroglobulinemia (WM) patients received either chlorambucil (n = 23); cyclophosphamide, vincristine, and prednisolone (CVP) (n = 5); fludarabine-based therapy (n = 5); or other combination chemotherapy (n = 7). Twenty-eight patients (70%) responded to first-line therapy with overall response rates as follows: chlorambucil, 17/23 (74%); CVP, 4/5 (80%); fludarabine-based regimen, 2/5 (40%); other combinations, 5/7 (71%). Twenty patients were treated at progression with chlorambucil, of whom 10 (50%) responded again, 6/13 having had chlorambucil initially, and 4/7 having had other therapy. Although there was a trend towards a survival advantage for patients who responded to chlorambucil, this difference was not statistically significant. At 6 and 11 years, overall survival was 36% v 18% and 15% v 0% for responders and nonresponders, respectively. The overall pattern was the same for patients treated initially with chlorambucil as with other therapy. This retrospective analysis confirms that chlorambucil is an effective first-line agent in WM and has activity when used at subsequent relapse.

Apheresis for Renal Disease

Many primary renal diseases are associated with either antibody deposition within the glomerulus or an antibody associated autoimmunity, as may be seen with certain vasculitidies. Examples of these diseases include Goodpasture's syndrome, cryoglobulinemia, antineutrophil cytoplasmic antibody positive syndromes, and other forms of rapidly progressive glomerulonephritis. Immunoglobulins also may be nephrotoxic to the tubules such as is the case with myeloma related light chains. Given the rapid removal of immunoglobulins by therapeutic plasma exchange, this modality has been considered an appealing management option in the treatment of these renal diseases. Although not classically considered as autoimmune diseases, thrombotic thrombocytopenic purpura and hemolytic uremic syndrome are related syndromes which often involve the kidneys. Although previously unexplained, it has been long appreciated that therapeutic plasma exchange (PE) can be a useful treatment for these microangiopathic hemolytic anemias, but the most recent insights into their pathogenesis suggest that PE may be beneficial by replacing a missing enzyme or removing pathogenic autoantibodies.

A case with acute renal failure complicated by Waldenström's macroglobulinemia and cryoglobulinemia

We encountered a 53-year-old man associated with acute renal failure caused by Waldenström's macroglobulinemia and type I cryoglobulinemia. Treatment with prednisolone and cyclophosphamide induced a rapid recovery from acute renal failure. Renal histology revealed endocapillary proliferation and lobular formation with scattered subendothelial, amorphous and periodic acid-Schiff (PAS)-positive materials in the glomerular capillaries which were positive for IgM on immunofluorescence study. Although the exact mechanism for pathophysiology of acute renal failure remains unknown, treatment with prednisolone and cyclophosphamide could induce a rapid recovery from acute renal failure accompanied by Waldenström's macroglobulinemia and type I cryoglobulinemia.

Nephrotic syndrome caused by protein thrombi in glomerulocapillary lumen in Waldenström's macroglobulinaemia

Waldenström's macroglobulinaemia (WM) is described as a disorder of plasmacytoid lymphocytes. The renal complications of WM are less common and severe than those of multiple myeloma. We present a case of WM complicated by nephrotic syndrome. A biopsy specimen of the kidney revealed the intraglomerular thrombi of immunoglobulin M paraprotein. Corticosteroid pulse therapy and plasmapheresis were effective in improving proteinuria and reducing protein thrombi. The nephrotic syndrome caused by protein thrombi in WM may be reversible, at least in its early stage.

Extensive intraglomerular thrombi of monoclonal IgM-kappa in a patient with malignant lymphoma

We describe an 80-year-old man who developed malignant lymphoma (ML) complicated by extensive intraglomerular thrombi of immunoglobulin M (IgM)-kappa monoclonal immunoglobulin. The clinical picture was characterized by nephrotic syndrome and systemic lymphadenopathy. Laboratory examination showed mild anemia and a small amount of monoclonal IgM-kappa in the blood. The histopathologic findings and surface immunoglobulin analysis of the lymph node biopsy specimen were consistent with CD5-positive diffuse large B-cell (type, IgM-kappa) lymphoma. The subsequent renal biopsy showed a massive deposition of amorphous material in the glomerular capillary lumens, subendothelial areas, and mesangium. Nodular glomerulosclerosis was not found. An immunofluorescent study showed that the deposits consisted of IgM-kappa monoclonal immunoglobulin. Ultrastructurally, the deposits were composed of granular electron-dense material. Chemotherapy was effective for both the ML and nephrotic syndrome, and the patient's urine analysis results returned to normal. The histopathologic manifestations of this case are rare, and the pathogenesis of these glomerular lesions was obviously associated with ML.