The spectrum of kidney pathology in B-cell chronic lymphocytic leukemia / small lymphocytic lymphoma: a 25-year multicenter experience

Type II cryoglobulinemia in a patient with chronic lymphocytic leukemia/small lymphocytic lymphoma and Sjögren's disease

Type II cryoglobulinemia is a rare disorder characterized by abnormal immunoglobulins (Igs) precipitating in the blood at low temperatures and redissolving upon warming. Sjogren's disease (SjD) is an autoimmune disorder involving secretory gland malfunction that leads to persistent dryness of the mouth and eyes. Here, we report the case of a 61-year-old woman with a 7-year history of SjD who was diagnosed with chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL). However, her complicated clinical features could not be sufficiently explained by this disease alone. Immunofixation electrophoresis revealed monoclonal IgM-κ and polyclonal IgG-κ. The presence of precipitated cryoglobulin and elevated rheumatoid factor levels confirmed a diagnosis of type II cryoglobulinemia for this patient. To the best of our knowledge, this case represents the first report of a patient with CLL/SLL, SjD, and type II cryoglobulinemia, which increased our understanding of immune system-related disorders. Because certain similar mechanisms are involved in the pathogenesis of these three diseases, a combination treatment of rituximab, ibrutinib, and dexamethasone resulted in a favorable prognosis for this patient.

Unusual Cases of Monoclonal Gammopathy of Renal Significance

Introduction

Monoclonal gammopathy of renal significance (MGRS) is a rare entity describing patients with renal impairment related to the secretion of immunoglobulins without hematological criteria for treatment of a specific disease. We present 3 cases of MGRS identified at our center that were either rare or difficult to diagnose. Case Presentations. The first patient presented with monoclonal membranoproliferative glomerulonephritis in the context of known chronic lymphocytic leukemia (CLL), diagnosed about 10 years prior. She presented with nephritic syndrome with serum protein electrophoresis revealing an IgG/lambda peak of less than 1 g/L, stable from the last few years. A renal biopsy confirmed a diagnosis of monoclonal membranoproliferative glomerulonephritis with granular IgG and C3 deposits of various sizes. The second patient presented with renal TMA in the context of IgM MGUS. The patient was admitted for acute nephritic syndrome and thrombotic microangiopathy. Serum protein electrophoresis demonstrated IgM/kappa paraprotein at 1.8 g/L, with a kappa/lambda ratio of 5.48. Renal biopsy demonstrated endocapillary proliferative glomerulonephritis associated with the presence of numerous monotypic IgM/kappa intracapillary pseudothrombi. Characteristic changes of thrombotic microangiopathy were also described. The third patient presented with immunotactoid glomerulonephritis likely from small B-cell lymphoma that later transformed to DLBCL. The patient presented with acute renal failure with IgM/kappa paraprotein of less than 1 g/L on electrophoresis and with a kappa/lambda ratio of 7.09. A diagnosis of immunotactoid glomerulonephritis was made on renal biopsy. Bone marrow with limited specimen revealed a B-cell infiltrate. Biopsy of a breast lesion was compatible with diffuse large B-cell lymphoma (DLBCL). Lymphomatous cells expressed IgM/kappa, thus confirming paraprotein-associated renal lesion.

Conclusion

We described 3 different cases of MGRS, highlighting the diversity of renal pathohistological presentations and different associated lymphoproliferative disorders. Biopsy should rapidly be considered, as early diagnosis of MGRS is essential to initiate clone-directed therapy promptly to prevent progression to ESRD or hematologic progression to malignancy.

Extramedullary and extranodal manifestations in chronic lymphocytic leukemia - an update

Chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) is a common leukemia characterized by clonal expansion of mature CD5+/CD23 + B cells in the blood, bone marrow (BM) and lymphoid tissues. CLL can undergo extramedullary and extranodal infiltration, with one study noting an incidence of only 0.3 per 100,000 people, and in 17.6% of CLL patients in another report. The most common extranodal sites of leukemic involvement are the skin and central nervous system; however, other organs, including liver, lungs, kidney, gastrointestinal tract, bone, prostate and heart, are occasionally involved. The prognostic significance of extra-medullary CLL is still under debate, but the prognosis in such patients seems to be better in the era of novel targeted drugs. Following a diagnosis of extranodal CLL, survival appears to depend on the site of infiltration. This review presents an overview of CLL in patients with extramedullary and extranodal leukemic lesions, focusing on its epidemiology, pathogenesis, prognosis, clinical characteristics and treatment results.

Case report: Bruton tyrosine kinase inhibitor as therapy for chronic lymphocytic leukemia infiltrating a kidney allograft

The burden of chronic lymphocytic leukemia (CLL) in the prognosis of solid organ transplant (SOT) recipients seems non-negligible. Whether transplanting a patient with previous CLL is safe or what is the optimal monitoring and treatment management after transplantation is still unclear and only based on few case series and reports. Therefore, we aimed to contribute to this understanding by reporting the first documented case of a clinically significant CLL with biopsy-proven infiltration of the kidney allograft and its successful management with a Bruton tyrosine kinase inhibitor (BTKi). We then reviewed the related literature, with a focus on CLL and kidney transplantation. Our main message is that BTKi may represent a safe and effective intervention to prevent the hazardous patient and graft outcomes of CLL in SOT patients.

Case report: Acute kidney injury as the initial manifestation of chronic lymphocytic leukemia/small lymphocytic lymphoma

Chronic lymphocytic leukemia (CLL) is a lymphoproliferative disorder often diagnosed after incidental finding of leukocytosis. Renal involvement is usually clinically silent. Symptomatic renal impairment due to CLL/small lymphocytic lymphoma (SLL) cell infiltration in the kidney tissue is uncommon, and acute kidney injury (AKI) as a presenting feature is rare. In this case report, we describe the case of a patient with AKI caused by CLL/SLL infiltration as a presenting feature. Our report highlights the possibility of kidney injury as the first evident symptom of CLL/SLL. Kidney biopsy is the mainstay in these cases in order to establish a diagnosis. Treatment with zanubrutinib resulted in improved kidney function.

A case report of pre-eclampsia-like endothelial injury in the kidney of an 85-year-old man treated with ibrutinib

Background

Glomerular endotheliosis is the pathognomonic glomerular lesion in pre-eclampsia that has also been described in those taking tyrosine kinase inhibitors for cancer treatment. Ibrutinib is a Bruton’s tyrosine kinase inhibitor used to treat chronic lymphocytic leukemia (CLL). We report the first known case of glomerular endotheliosis on kidney biopsy in a patient on ibrutinib monotherapy.

Case presentation

The patient presented with acute on chronic kidney disease, proteinuria, low C3 and C4 and a high rheumatoid factor titer. A kidney biopsy was performed to confirm a preliminary diagnosis of membranoproliferative glomerulonephritis (MPGN), the most common glomerular disease in patients with CLL. Unexpectedly, the kidney biopsy showed pre-eclampsia-like lesions on light and electron microscopy: occlusion of glomerular peripheral capillary lumens by swollen reactive endothelial cells. Findings of glomerulonephritis were not seen, and there were no specific glomerular immune deposits by immunofluorescence or electron microscopy.

Conclusions

CLL is known to cause glomerular lesions, mainly MPGN. There is increasing evidence that ibrutinib, a major treatment for CLL, can cause kidney disease, but the precise pathology is not characterized. We present a patient with CLL on ibrutinib with signs of glomerular endotheliosis. Based on the absence of CLL-induced kidney pathologies typically seen on the kidney biopsy and the non-selectivity of ibrutinib, we attributed the glomerular endotheliosis to ibrutinib. In pre-eclampsia, increased soluble fms-like tyrosine kinase 1 (sFlt1) levels induce endothelial dysfunction by decreasing vascular endothelial growth factor (VEGF). Ibrutinib has been demonstrated to have non-selective tyrosine kinase inhibition, including inhibition of VEGF receptor (VEGFR) and epidermal growth factor receptor (EGFR). VEGFR and EGFR inhibitors have recently been described in the literature to cause hypertension, proteinuria, and glomerular endotheliosis. Kidney biopsy should be performed in CLL patients on ibrutinib that present with acute kidney injury (AKI) or proteinuria to determine whether the clinical picture is attributable to the disease itself or a complication of the therapy.

Unusual complications in the management of chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL) is a common, indolent disease that typically presents with a proliferation of mature, immunologically dysfunctional CD5+ B-cells which preferentially occupy the bone marrow, peripheral blood and lymphoid organs. Immune dysfunction leads to an increase in autoimmune diseases which occur in approximately 10% of patients with CLL. Autoimmune cytopenias are the most common, but other organs may be affected as well. The treatment of these conditions typically depends on the extent of CLL and severity of symptoms, but generally consists of CLL-directed therapies, immunosuppression or both. CLL may also infiltrate extranodal sites in the body. Symptomatic extranodal CLL or extranodal disease which threatens normal organ function is an indication for initiation of CLL-directed therapy. The following review summarizes autoimmune and extranodal complications that can occur in patients with CLL and our suggested approach to their treatment.

An Exceptional Case of Light Chain Only Variant of Proliferative Glomerulonephritis with Monoclonal Immunoglobulin Deposits Secondary to Chronic Lymphocytic Leukemia: A Case Report and Review of the Literature

We present the case of an 86-year-old Caucasian male with an 11-year history of low-grade chronic lymphocytic leukemia (CLL) presenting with nephrotic syndrome (NS). Renal biopsy findings showed a diffuse mesangial and endocapillary proliferative glomerulonephritis (GN) lesion with fine granular deposits, consistent with a rare morphologic variant of proliferative glomerulonephritis with monoclonal immunoglobulin deposits (PGNMID)-lambda light chain (LC) only. Monthly combination therapy of rituximab (500 mg/m² on day 1), fludarabine (30 mg/m² on days 1–3), and cyclophosphamide (750 mg/m² on days 1–3) was administered. Five courses of this regimen resulted in hematological remission, as well as a partial renal response with a reduction in the spot urine protein-to-creatinine ratio (UPCR) of 815.3 mg/g (reduction > 50% proteinuria without improvement in kidney function). This condition is a rare morphological variant of PGNMID, poorly described in CLL patients. We review the literature and suggest that this case provides sheds light on the unknown pathophysiological mechanisms of monoclonal immunoglobulins (MIg)-mediated glomerular damage in CLL patients, and may be helpful for the investigation of a more effective treatment.

Unusual cause of light chain cast nephropathy

Acute kidney injury due to light chain cast nephropathy is increasingly recognised in patients with haematological malignancies; however, the management and prognosis of this disease remain poorly understood. We describe a case of a 78-year-old woman with known chronic lymphocytic leukaemia (CLL) who presented with fatigue and weight loss. She was found to have acute kidney injury, which rapidly worsened during admission. Kidney biopsy showed light chain cast nephropathy and bone marrow biopsy confirmed B-cell CLL. She was started on ibrutinib, halting further deterioration in her renal function and avoiding renal replacement therapy in the first 8 months.

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.

A Diverse Spectrum of Immune Complex- and Complement-Mediated Kidney Diseases Is Associated With Mantle Cell Lymphoma

Introduction

There are limited reports on kidney biopsy findings in patients with mantle cell lymphoma (MCL).

Methods

We initiated a multi-institutional, retrospective review of kidney biopsy findings in patients with active and treated MCL.

Results

A total of 30 patients with MCL and kidney biopsies were identified, with a median age of 67 (range 48-87) years, 73% of whom were men. A total of 20 patients had active MCL at the time of biopsy, of whom 14 (70%) presented with acute kidney injury (AKI), proteinuria and/or hematuria, and biopsy findings potentially attributable to lymphoma. Of the 14, 11 had immune complex (IC) or complement-mediated (C3) disease including proliferative glomerulonephritis (GN) with monotypic Ig deposits (PGNMID [2]), C3GN, (2), secondary membranous nephropathy (MN [3]), tubular basement membrane (TBM) deposits (2), and modest lupus-like GN (2). Lymphomatous infiltration was present in 8 of the 20 patients, 5 with coincident IC or C3 lesions. A total of 6 patients with available follow-up were treated for MCL, all with clinical remission of GN (2 PGNMID, 2 C3GN, and 2 MN).

Conclusion

MCL is associated with diverse monoclonal and polyclonal glomerular and extra-glomerular IC and C3 disease. For patients with active MCL and kidney dysfunction requiring biopsy, 70% had findings due or potentially due to lymphoma, including 55% with IC or C3 disease and 40% had lymphomatous kidney infiltration. IC and C3GN in the setting of active MCL was responsive to lymphoma-directed therapy.

An update of proliferative glomerulonephritis with monoclonal immunoglobulin deposits

As aging increases, monoclonal gammopathy is becoming more common, and monoclonal gammopathy of renal significance (MGRS) is gaining attention due to frequent renal involvement. Among MGRS, proliferative glomerulonephritis with monoclonal immunoglobulin deposits (PGNMID) is a special category. The disease was first described in 2004, and the research history on it is relatively short. Compared with other MGRS, the detection rate of circulating clones is lower in patients with PGNMID, which is easy to be missed and misdiagnosed in clinical work. In this review, the etiology and clinical features of PGNMID are discussed. It is noted that PGNMID is not only associated with MGRS, but also with malignancy, infection, and other factors. PGNMID is not a disease exclusive to the elderly, young people can also develop this disease. Due to the low detection rate of circulating clones in most patients, confirmation of the disease needs to be combined with renal pathology, which emphasizes the importance of completing light and heavy chain subtype staining. Treatment options for patients with PGNMID differ by etiology. For MGRS-associated PGNMID, the current treatment is primarily empirical and more research evidence is needed to fill the treatment gap.

The pathological features of leukemic cells infiltrating the renal interstitium in chronic lymphocytic leukemia/small lymphocytic lymphoma from a large single Chinese center

Background

Chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) is rare in Asians, and patients with CLL/SLL seldomly undergo kidney biopsy. The histopathological features and clinical relevance of tubulointerstitial injury in CLL/SLL have not been extensively characterized. Hence, we attempted to describe the clinical characteristics, renal pathology and clinical outcome of a well-characterized population of CLL/SLL patients with CLL cell infiltration in the renal interstitium from a large single center in China.

Methods

Between January 1st, 2010 and September 31st, 2020, 31946renal biopsies were performed at Peking University First Hospital, and 10 CLL/SLL patients with CLL cell infiltration in the renal interstitium were included. Complete clinical data were collected from these 10 patients, and renal specimens were examined by routine light microscopy, immunofluorescence and electron microscopy.

Results

The extent of the infiltrating CLL cells in patients with CLL/SLL varied among different patients and ranged from 10 to 90% of kidney parenchyma. Six (60%) of 10 patients presented with an extent of infiltrating CLL cells ≥50%. Interestingly, we found that three patients (3/10, 30%) expressed monoclonal immunoglobulins in the infiltrating CLL cells, and special cytoplasmic crystalline structures were found in two of the three patients by electron microscopy for the first time. Severe renal insufficiency (Scr ≥200 μmol/L) was associated with ≥50% interstitial infiltration of CLL cells in the renal interstitium.

Conclusions

The current study confirmed that CLL cells infiltrating the renal interstitium can directly secrete monoclonal immunoglobulins, indicating that the interstitial infiltrating CLL cells possibly cause renal injury directly by secreting monoclonal immunoglobulins in situ. This finding may prove a new clue to elucidate the pathogenetic mechanism of renal injury involved with CLL/SLL.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13000-021-01120-4.

Renal Diseases Associated with Hematologic Malignancies and Thymoma in the Absence of Renal Monoclonal Immunoglobulin Deposits

In addition to kidney diseases characterized by the precipitation and deposition of overproduced monoclonal immunoglobulin and kidney damage due to chemotherapy agents, a broad spectrum of renal lesions may be found in patients with hematologic malignancies. Glomerular diseases, in the form of paraneoplastic glomerulopathies and acute kidney injury with various degrees of proteinuria due to specific lymphomatous interstitial and/or glomerular infiltration, are two major renal complications observed in the lymphoid disorder setting. However, other hematologic neoplasms, including chronic lymphocytic leukemia, thymoma, myeloproliferative disorders, Castleman disease and hemophagocytic syndrome, have also been associated with the development of kidney lesions. These renal disorders require prompt recognition by the clinician, due to the need to implement specific treatment, depending on the chemotherapy regimen, to decrease the risk of subsequent chronic kidney disease. In the context of renal disease related to hematologic malignancies, renal biopsy remains crucial for accurate pathological diagnosis, with the aim of optimizing medical care for these patients. In this review, we provide an update on the epidemiology, clinical presentation, pathophysiological processes and diagnostic strategy for kidney diseases associated with hematologic malignancies outside the spectrum of monoclonal gammopathy of renal significance.

Changing paradigms in diagnosis and treatment of monoclonal gammopathy of undetermined significance (MGUS) and smoldering multiple myeloma (SMM)

Multiple myeloma (MM) is a highly heterogenous disease that exists along a continuous disease spectrum starting with premalignant conditions monoclonal gammopathy of undetermined significance (MGUS) and smoldering multiple myeloma (SMM) that inevitably precede MM. Over the past two decades, significant progress has been made in the genetic characterization and risk stratification of precursor plasma cell disorders. Indeed, the clinical introduction of highly effective and well-tolerated drugs begs the question: would earlier therapeutic intervention with novel therapies in MGUS and SMM patients alter natural history, providing a potential curative option? In this review, we discuss the epidemiology of MGUS and SMM and current models for risk stratification that predict MGUS and SMM progression to MM. We further discuss genetic heterogeneity and clonal evolution in MM and the interplay between tumor cells and the bone marrow (BM) microenvironment. Finally, we provide an overview of the current recommendations for the management of MGUS and SMM and discuss the open controversies in the field in light of promising results from early intervention clinical trials.

Acute Kidney Injury in Oncology Patients

With rapid progress in cancer diagnosis and treatment in the last two decades, outcomes in oncological patients have improved significantly. However, the incidence of acute kidney injury (AKI) in this population has also increased significantly. AKI complicates many aspects of patients' care and adversely affects their prognoses; thus, accurately diagnosing the risk factors for AKI ensures appropriate management. AKI may be caused by pre-renal, intrinsic renal, and post-renal reasons, as well as for combined reasons. This review summarizes the potential etiologies of AKI according to the three classifications. For each underlying cause of AKI, the cancer itself and/or cancer treatment may contribute to a patient developing AKI. Therefore, we present disease- and treatment-related factors for each cause category, with special focus on immune checkpoint inhibitors, which are being used increasingly more often. It is important for nephrology services to be knowledgeable to provide the best level of care.

IgM monoclonal gammopathy with heavy-and-light-chain amyloidosis resembling fibrillary glomerulonephritis determined by tandem mass spectrometry: a case report

BACKGROUND

Fibrillary glomerulonephritis (FGN) is distinguished from amyloidosis by thicker fibrils and the lack of staining with histochemical dyes typically reactive with amyloid. However, congophilic FGN has been proposed recently and adding laser microdissection followed by mass spectrometry (LMD/MS) to conventional pathological methods would be helpful to diagnose FGN. Here, we report a patient initially diagnosed with FGN whose final pathological diagnosis was changed to immunoglobulin heavy-and-light-chain amyloidosis (AHL) after LMD/MS.

CASE PRESENTATION

A 75-year-old male developed nephrotic syndrome. Protein electrophoresis showed IgM κ type M proteinemia and he was diagnosed with IgM monoclonal gammopathy. A renal biopsy was performed and pathological examination showed marked periodic acid-Schiff-positive enlargement of the mesangial region and silver stain positivity, but weak direct fast scarlet staining. Immunofluorescence analysis showed monoclonal deposition of IgM-κ chain in the glomerulus. Under electron microscopy, the fibrils were about 20 nm in diameter, which was thicker than typical amyloid fibrils. Based on these findings, the patient was diagnosed with FGN. Although cyclophosphamide and prednisolone were administered, his renal function deteriorated and progressed to end stage renal disease requiring maintenance hemodialysis. As congophilic FGN has been recognized since 2018, Congo red staining and LMD/MS were performed. The Congo red staining was positive and LMD/MS results indicated that this was a case of AHL.

CONCLUSIONS

We reported a case of μ and κ chain AHL resembling FGN requiring LMD/MS for definitive diagnosis. Since FGN and amyloidosis exhibit pathological findings, even if Congo red staining is positive, LMD/MS needs to be considered in cases atypical pathological findings, such as silver stain positivity or thicker fibrils.

Crystalglobulin-associated nephropathy presenting as MGRS in a case of monoclonal B-cell lymphocytosis: a case report

BACKGROUND

Crystalglobulin-associated nephropathy (CAN), a rare subtype of monoclonal gammopathy, usually associated with multiple myeloma and occasionally monoclonal gammopathy of uncertain significance (MGUS), is characterized by occluding monoclonal pseudothrombi within renal glomerular capillaries and/or interstitial arterioles. Ultrastructurally, these pseudothrombi are unique for having a crystalline substructure. We describe a case of an adult patient with monoclonal B-cell lymphocytosis (MBL) and acute renal failure whose kidney biopsy revealed a rare diagnosis of CAN.

CASE PRESENTATION

A 63-year old male presented with a 2-month history of edema, arthralgia and malaise. He had acute kidney injury with hematoproteinuria on urine analysis. Serum and urine protein electrophoresis were both negative. A renal biopsy however revealed features of CAN. Organomegaly, bone pain and lymphadenopathy were absent. A repeat serum electrophoresis was positive for IgA kappa and a free light chain assay showed elevated free kappa light chains. Flow cytometry done subsequently revealed a diagnosis of MBL, chronic lymphocytic leukemia (CLL) type.

CONCLUSION

CAN in association with MBL/CLL has not been previously described in literature, and our case highlights yet another instance of monoclonal gammopathy of renal significance (MGRS) where a small B-cell clone resulted in extensive renal pathology without systemic manifestations.

Lymphomas with kidney involvement: the French multicenter retrospective LyKID study

The LyKID study is a nationwide survey in France of lymphoma patients with renal involvement based on biopsy and/or imaging, to evaluate its impact on disease outcome and renal function. A total of 87 adult cases of B or T-cell lymphomas were retrospectively analyzed. Interstitial topography was observed in most of the kidney biopsies (54/66; 80%). Kidney failure (glomerular filtration rate <60 mL/min/1.73 m²) was present in 47% of patients and was associated with non-significantly different outcome. After lymphoma treatment, 44% of patients had persistent chronic kidney failure (CKF); kidney failure at diagnosis was the only parameter associated with CKF in multivariate analysis. DLBCL (diffuse large B-cell lymphomas) represented half of the series, with noticeably CNS (central neurological system) relapse in 17% patients, while fewer than one of two patients had received CNS prophylaxis. To our knowledge, the LyKID study represents the largest published non-autopsy lymphoma series with renal involvement.

Proteomics-inspired precision medicine for treating and understanding multiple myeloma

Introduction

Remarkable progress in molecular characterization methods has led to significant improvements in how we manage multiple myeloma (MM). The introduction of novel therapies has led to significant improvements in overall survival over the past 10 years. However, MM remains incurable and treatment choice is largely based on outdated risk-adaptive strategies that do not factor in improved treatment outcomes in the context of modern therapies.

Areas covered

This review discusses current risk-adaptive strategies in MM and the clinical application of proteomics in the monitoring of treatment response, disease progression, and minimal residual disease (MRD). We also discuss promising biomarkers of disease progression, treatment response, and chemoresistance. Finally, we will discuss an immunomics-based approach to monoclonal antibody (mAb), vaccine, and CAR-T cell development.

Expert opinion

It is an exciting era in oncology with basic scientific knowledge translating in novel therapeutic approaches to improve patient outcomes. With the advent of effective immunotherapies and targeted therapies, it has become crucial to identify biomarkers to aid in the stratification of patients based on anticipated sensitivity to chemotherapy. As a paradigm of diseases highly dependent on protein homeostasis, multiple myeloma provides the perfect opportunity to investigate the use of proteomics to aid in precision medicine.

The evaluation of monoclonal gammopathy of renal significance: a consensus report of the International Kidney and Monoclonal Gammopathy Research Group

The term monoclonal gammopathy of renal significance (MGRS) was introduced by the International Kidney and Monoclonal Gammopathy Research Group (IKMG) in 2012. The IKMG met in April 2017 to refine the definition of MGRS and to update the diagnostic criteria for MGRS-related diseases. Accordingly, in this Expert Consensus Document, the IKMG redefines MGRS as a clonal proliferative disorder that produces a nephrotoxic monoclonal immunoglobulin and does not meet previously defined haematological criteria for treatment of a specific malignancy. The diagnosis of MGRS-related disease is established by kidney biopsy and immunofluorescence studies to identify the monotypic immunoglobulin deposits (although these deposits are minimal in patients with either C3 glomerulopathy or thrombotic microangiopathy). Accordingly, the IKMG recommends a kidney biopsy in patients suspected of having MGRS to maximize the chance of correct diagnosis. Serum and urine protein electrophoresis and immunofixation, as well as analyses of serum free light chains, should also be performed to identify the monoclonal immunoglobulin, which helps to establish the diagnosis of MGRS and might also be useful for assessing responses to treatment. Finally, bone marrow aspiration and biopsy should be conducted to identify the lymphoproliferative clone. Flow cytometry can be helpful in identifying small clones. Additional genetic tests and fluorescent in situ hybridization studies are helpful for clonal identification and for generating treatment recommendations. Treatment of MGRS was not addressed at the 2017 IKMG meeting; consequently, this Expert Consensus Document does not include any recommendations for the treatment of patients with MGRS.

This Expert Consensus Document from the International Kidney and Monoclonal Gammopathy Research Group includes an updated definition of monoclonal gammopathy of renal significance (MGRS) and recommendations for the use of kidney biopsy and other modalities for evaluating suspected MGRS

Cardiac involvement in heavy and light chain amyloidosis: A case report and literature review

INTRODUCTION

Heavy and light chain amyloidosis is an extremely rare condition. There are few reports referring to the clinical impact of cardiac involvement in heavy and light chain amyloidosis, and the significance of myocardial impairment has not yet been completely explained.

PATIENT CONCERNS

A 66-year-old Japanese man was admitted to our hospital presenting with nephrotic syndrome and congestive heart failure.

DIAGNOSIS

Kidney and endoscopic gastric mucosal biopsy demonstrated congophilic hyalinization in most of the glomeruli and surrounding vessel walls, which were highly positive for immunoglobulin A and lambda. Finally, the patient was diagnosed as an atypical multiple myeloma with systemic heavy and light chain amyloidosis.

INTERVENTIONS

The patient was referred to hematology for further treatment and was moved to another hospital for the administration of chemotherapy using melphalan and dexamethasone.

OUTCOMES

The patient was still alive after 15-month follow-up from the initial diagnosis.

CONCLUSION

Initial screening and follow-up for cardiac involvement are important for heavy and light chain amyloidosis. Further investigation for the prognosis of heavy and light chain amyloidosis is required to improve the strategies of diagnosis and treatment options for patients with this disease.

Multiple Faces of Chronic Lymphocytic Leukaemia: A Patient with Renal, Cardiac, and Skeletal Complications

We describe a patient who had chronic lymphocytic leukaemia (CLL) Binet stage A at presentation with further evidence of disease at multiple sites but who initially required no treatment. However, several years later, her peripheral blood lymphocyte count started to increase, and soon after that she suffered an acute myocardial infarct (in the absence of coronary atheroma) together with proteinuric renal failure due to membranoproliferative glomerulonephritis. Her renal function improved markedly following anti-CLL chemotherapy. We postulate that her cardiac and renal disease were both complications of her CLL. In patients with CLL who develop new clinical signs or symptoms (even if apparently unrelated), consideration should be given as to whether these may be disease complications as this may serve as an indication to commence anti-CLL therapy; close liaison between different specialties is vital.

Renal involvement in chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL) is the most commonly diagnosed adult leukemia in the USA and Western Europe. Kidney disease can present in patients with CLL as a manifestation of the disease process such as acute kidney injury with infiltration or with a paraneoplastic glomerular disease or as a manifestation of extra renal obstruction and tumor lysis syndrome. In the current era of novel targeted therapies, kidney disease can also present as a complication of treatment. Tumor lysis syndrome associated with novel agents such as the B-cell lymphoma 2 inhibitor venetoclax and the monoclonal antibody obinutuzumab are important nephrotoxicities associated with these agents. Here we review the various forms of kidney diseases associated with CLL and its therapies.

[Chronic lymphoid leukemia and renal complication: Report on 10 cases from Marseille over 16 years]

INTRODUCTION

Chronic lymphoid leukemia (CLL) is a hematological malignant disease, associated with a clonal B cell proliferation. The incidence is 4400 new cases per year in France. The prevalence increases with age with a median age at diagnostic of 65 years. Renal involvement is rare and estimated at 1.2% of patients with CLL. Renal pathological diagnoses associated with CLL are variable and are not always related to the hematological disease. We report here on cases of patients with CLL who underwent a renal biopsy over the past 16 years in Marseille.

METHODS

All cases of renal biopsies performed in patients with CLL between2000 and 2016 in Marseille were included. Pathological analysis was performed by the same experimented pathologist. Data were collected at the time of biopsy and after treatment.

RESULTS

Ten patients were included in this study. The reason for renal biopsy was acute kidney injury or the onset of nephrotic syndrome. We report on 4 cases of membranous nephropathy, 1 minimal change disease, 1 cryglobulinemia-related membrano-proliferative glomerulonephritis, 1 light chain amyloidosis, 1 fibrillary glomerulonephritis, 1 interstitial monoclonal infiltration and one case of non-specific tubular lesions. Only one patient was treated before the biopsy, 7 patients received a specific hematological treatment of CLL because of its renal involvement. Renal and hematological responses were variable.

CONCLUSION

Renal involvement of CLL is rare and is not mentioned in the Binet classification. Yet, it can be severe, with acute kidney injury or nephrotic syndrome, and can lead to the initiation of a specific treatment. The most frequent presentation this series was secondary MN, which differs from previous series.

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.

Proteinuria, Hypoalbuminemia, and Chronic Lymphocytic Leukemia: An Unusual Trio

Chronic lymphocytic leukemia (CLL) is a chronic, progressive lymphoproliferative disorder characterized by a monoclonal population of functionally incompetent lymphocytes. Renal involvement is rare and poorly described. A 57-year-old male with no prior medical history was diagnosed with CLL and followed with a watch and wait approach. He was referred to our institution several months later due to concern for Richter's transformation to diffuse large B-cell lymphoma. A positron emission tomography/computed tomography scan showed no evidence of diffuse large B-cell lymphoma; however, the patient was noted to have hypoalbuminemia, nephrotic range proteinuria, an acute left renal vein thrombus, and a right pulmonary embolus. A nephrotic syndrome workup including autoimmunity and infection was unremarkable, and a kidney biopsy was deferred due to concern for renal compromise in the setting of a renal vein thrombus. The patient was treated with 6 cycles of reduced-dose fludarabine, cyclophosphamide, and rituximab for a presumed CLL-associated nephrotic syndrome and anticoagulation for his venous thromboemboli. At 6-month follow-up, the patient achieved complete remission of his CLL with normalization of all cell lines and resolution of his nephrotic range proteinuria. Repeat computed tomography scans showed no evidence of recurrent venous thromboemboli. This case demonstrates a potential role of empiric chemotherapy in cases of CLL-associated nephrotic syndrome given its potentially life-threatening sequelae and response to treatment.

Monoclonal B lymphocytosis and minimal change disease: a new monoclonal B-cell disorder of renal significance?

Chronic lymphocytic leukemia (CLL) may induce renal complications, which are becoming increasingly common, but in this context the occurrence of minimal change disease (MCD) remains rare. Monoclonal B lymphocytosis (MBL) is a precursor state of CLL and is currently under recognized. Since MBL is seen as a benign disorder that rarely evolves into CLL, screening for MBL is not standardized and does not require any treatment. When reviewing renal disease associated with MBL, there is very scant data in the literature and to date there is no case describing the association between MBL and MCD. Here, we describe the case of a 71-year old woman admitted for nephrotic syndrome (NS). We diagnosed a MBL. Kidney biopsy revealed MCD. Treatment with corticosteroids was introduced but no improvement was observed. Chemotherapy with rituximab and chlorambucil was thus started, leading to complete remission of both MBL and MCD. To our knowledge, this is the first description of the association of MBL and MCD. This case suggests that screening for MBL may have unexpected diagnostic and therapeutic implications in patients presenting with seemingly idiopathic NS.

Renal Masses Detected on FDG PET/CT in Patients With Lymphoma: Imaging Features Differentiating Primary Renal Cell Carcinomas From Renal Lymphomatous Involvement

OBJECTIVE

The purpose of this study is to analyze the ¹⁸F-FDG PET/CT features of solid renal masses detected in patients with lymphoma and to evaluate the ability of PET/CT to differentiate renal cell carcinoma (RCC) from renal lymphomatous involvement.

MATERIALS AND METHODS

Thirty-six patients with solid renal masses on PET/CT performed for staging or follow-up of lymphoma were evaluated retrospectively. The features recorded for each renal mass included the following standardized uptake values (SUVs) on PET/CT: the maximum SUV (SUV_max), the mean SUV (SUV_mean), the ratio of the SUV_max of the tumor to that of the normal kidney cortex, the ratio of the SUV_mean of the tumor to that of the normal kidney cortex, the ratio of the SUV_max of the tumor to that of the normal liver, and the ratio of the SUVmean of the tumor to that of the normal liver. Renal mass size and margins (well defined vs infiltrative) and the presence of calcifications were evaluated on CT. Renal biopsy results were used as the reference standard. Relationships between imaging parameters and histopathologic findings were assessed.

RESULTS

Of the 36 renal masses evaluated, 22 (61.1%) were RCCs and 14 (38.9%) were renal lymphomas. All SUV metrics were higher for renal lymphomas than for RCCs (p < 0.0001, for all). All renal lymphomas had an SUV_max higher than 5.98 g/mL (median, 10.99 g/mL), whereas all RCCs had an SUV_max lower than 5.26 g/mL (median, 2.91 g/mL). No statistically significant differences in mass size or margins were found between RCCs and renal lymphoma.

CONCLUSION

PET/CT features may be useful for differentiating RCCs from renal involvement in patients with lymphoma with solid renal masses.

Monotypic plasma cell interstitial nephritis as the only clinical manifestation in a patient with previously undiagnosed indolent multiple myeloma: A case report

INTRODUCTION

Predominantly monotypic plasma cell infiltrates are an uncommon renal finding in patients with malignant lymphoplasmacytic proliferation.

CASE PRESENTATION

We report the case of a 52-year-old man with chronic kidney disease and significant proteinuria associated with a monoclonal immunoglobulin spike (IgGκ). Kidney biopsy revealed the presence of atypical multinucleated CD138 plasma cells with voluminous nuclei stained exclusively with a κ antibody. Electron microscopy showed mesangial and segmental parietal electron-dense, nonorganized hyaline deposits without immunogold labeling for the κ light chain. The bone marrow aspirate revealed 6% of apparently mature plasmocytes without dystrophy. We therefore concluded that the patient had an indolent multiple myeloma with specific renal involvement in the form of malignant monotypic interstitial plasmacytic infiltration. We initiated a specific chemotherapy regimen including bortezomib-cyclophosphamide-dexamethasone. After 4 months of follow-up, creatinine levels had improved slightly and free κ light-chain levels had decreased significantly within the normal range.

CONCLUSION

This case highlights the need to consider neoplastic interstitial plasma cell infiltration systematically in patients diagnosed with an apparently benign monoclonal gammopathy and to consider adaptation of the chemotherapy regimen, to improve renal function.

Membranoproliferative glomerulonephritis and acute renal failure in a patient with chronic lymphocytic leukemia: Response to obinutuzumab

OBJECTIVE/BACKGROUND

Membranoproliferative glomerulonephritis (MPGN) is a common extramedullary renal presentation in chronic lymphocytic leukemia (CLL) and can present with either a frank renal failure or proteinuria. One of its etiologies has been attributed to a paraneoplastic, immune complex phenomenon occurring in CLL. Although there is no standard of care in such patients, use of anti-CD20 monoclonal antibodies like rituximab have been used before in such patients with variable responses. Obinutuzumab is a novel, type II, immunoglobulin-G1 monoclonal antibody with a higher efficacy than rituximab and has an established safely profile in patients with comorbidities and poor renal functions. There are no such reported cases of MPGN in CLL being treated with obinutuzumab.

METHODS

We used the standard doses of obinutuzumab in our elderly patient (78-year-old woman) with high-risk CLL due to an underlying TP53 mutation, along with a MPGN-related acute renal failure.

RESULTS

The patient achieved complete remission after six cycles of obinutuzumab; however, she remained positive for minimal residual disease on flow cytometry. Her renal function improved completely, suggesting a complete response of her underlying MPGN.

CONCLUSION

Obinutuzumab has an established safety profile in patients with CLL, but our case is the first reported case of a paraneoplastic, immune complex-mediated MPGN in CLL being treated with obinutuzumab. Obinutuzumab should be explored as a potential option in patients with CLL and MPGN.

Renal complications in chronic lymphocytic leukemia and monoclonal B-cell lymphocytosis: the Mayo Clinic experience

While the renal complications of plasma cell dyscrasia have been well-described, most information in patients with chronic lymphocytic leukemia and monoclonal B-cell lymphocytosis is derived from case reports. This is a retrospective analysis of patients with chronic lymphocytic leukemia or monoclonal B-cell lymphocytosis who underwent kidney biopsy for renal insufficiency and/or nephrotic syndrome. Between January 1995 and June 2014, 49 of 4,024 (1.2%) patients with chronic lymphocytic leukemia (n=44) or monoclonal B-cell lymphocytosis (n=5) had a renal biopsy: 34 (69%) for renal insufficiency and 15 (31%) for nephrotic syndrome. The most common findings on biopsy were: membranoproliferative glomerulonephritis (n=10, 20%), chronic lymphocytic leukemia interstitial infiltration as primary etiology (n=6, 12%), thrombotic microangiopathy (n=6, 12%), and minimal change disease (n=5, 10%). All five membranoproliferative glomerulonephritis patients treated with rituximab, cyclophosphamide and prednisone-based regimens had recovery of renal function compared to 0/3 patients treated with rituximab with or without steroids. Chronic lymphocytic leukemia infiltration as the primary cause of renal abnormalities was typically observed in relapsed/refractory patients (4/6). Thrombotic microangiopathy primarily occurred as a treatment-related toxicity of pentostatin (4/6 cases), and resolved with drug discontinuation. All cases of minimal change disease resolved with immunosuppressive agents only. Renal biopsy plays an important role in the management of patients with chronic lymphocytic leukemia or monoclonal B-cell lymphocytosis who develop renal failure and/or nephrotic syndrome.