Multiple Myeloma

End-Stage Renal Disease From Cast Nephropathy in a Teenager With Neuroendocrine Carcinoma

Cast nephropathy is the most common manifestation of renal injury in patients with multiple myeloma but is rarely reported in other conditions. We are reporting our experience in caring for a teenager with a metastatic neuroendocrine carcinoma who developed rapidly progressive kidney injury that advanced to end-stage renal disease. On renal biopsy extensive tubular necrosis and intratubular eosinophilic casts were noted. This previously unreported finding should prompt oncologists to closely monitor for such a complication in patients with secretory tumors. Whether early plasmapheresis could be of benefit, as has been tried in multiple myeloma, remains to be determined.

Pharmacokinetics, safety, and efficacy of lenalidomide plus dexamethasone in patients with multiple myeloma and renal impairment

PURPOSE

Renal impairment (RI) is a common comorbidity in multiple myeloma (MM). Current dose adjustments recommended for renally excreted lenalidomide are based on data from noncancer patients. This study evaluated the pharmacokinetics, safety, efficacy, and exposure-response for lenalidomide plus dexamethasone in patients with relapsed/refractory MM and stable RI using the recommended dose adjustments.

METHODS

This phase 2 multicenter, open-label study stratified patients into 5 groups based on creatinine clearance (CrCl) calculated by Cockcroft-Gault equation: normal renal function (CrCl > 80 mL/min), mild RI (50 ≤ CrCl ≤ 80 mL/min), moderate RI (30 ≤ CrCl < 50 mL/min), severe RI (CrCl < 30 mL/min), and end-stage renal disease requiring hemodialysis. Dosing was based on the lenalidomide label.

RESULTS

Among 38 patients, the median age was 68 (range 62-74) years, and poorer renal function was associated with older age, more advanced disease, and more lines of prior therapy. Lenalidomide clearance declined with decreased CrCl. Mean lenalidomide area under plasma concentration-time curve (AUC) was within ±25 % of the target AUC in each group. Overall response was 76 %, and safety profiles were similar across groups, with no exposure-dependent trend in efficacy or toxicity. Estimated glomerular filtration rates calculated using the simplified Modification of Diet in Renal Disease equation highly correlated with lenalidomide clearance and, in 87 % of patients, would lead to assigning the same starting dose of lenalidomide as CrCl.

CONCLUSIONS

In patients with stable renal function, the recommended dose adjustments achieved proper plasma exposure and similar safety and efficacy across renal groups.

Pomalidomide plus low-dose dexamethasone in patients with relapsed/refractory multiple myeloma and moderate renal impairment: a pooled analysis of three clinical trials

Renal impairment (RI) is a major comorbidity in patients with multiple myeloma (MM). Here we present the pooled safety and efficacy analysis of three clinical trials (MM-002, MM-003, and MM-010) of pomalidomide + low-dose dexamethasone (POM + LoDEX) in patients with moderate RI (creatinine clearance [CrCl] ≥ 30 to <60 mL/min) and without RI (≥ 60 mL/min). Trial protocols were approved by the institutional review board of each site involved. Patients with RI were older than patients without RI, although other baseline characteristics were similar. The dosing and safety profile of POM + LoDEX was similar across RI subgroups. Median overall response rate, progression-free survival, time to progression, and duration of response were not significantly different between RI subgroups. However, patients with vs. without RI had significantly shorter median overall survival (10.5 vs. 14.0 months, respectively; p = .004). This analysis demonstrates that POM + LoDEX is a safe and effective treatment for patients with moderate RI. The trials were registered at ClinicalTrials.gov as NCT00833833 (MM-002), NCT01311687 (MM-003), and NCT01712789 (MM-010) and at EudraCT as 2010-019820-30 (MM-003) and 2012-001888-78 (MM-010).

ESRD due to Multiple Myeloma in the United States, 2001-2010

Although management of multiple myeloma has changed substantially in the last decade, it is unknown whether the burden of ESRD due to multiple myeloma has changed, or whether survival of patients with multiple myeloma on RRT has improved. Regarding ESRD due to multiple myeloma necessitating RRT in the United States, we evaluated temporal trends between 2001 and 2010 for demography-adjusted incidence ratios, relative to rates in 2001-2002, and mortality hazards from RRT initiation, relative to hazards in 2001-2002. In this retrospective cohort study, we used the US Renal Data System database (n=1,069,343), 2001-2010, to identify patients with ESRD due to multiple myeloma treated with RRT (n=12,703). Demography-adjusted incidence ratios of ESRD from multiple myeloma decreased between 2001-2002 and 2009-2010 in the overall population (demography-adjusted incidence ratio 0.82; 95% confidence interval, 0.79 to 0.86) and in most demographic subgroups examined. Mortality rates were 86.7, 41.4, and 34.4 per 100 person-years in the first 3 years of RRT, respectively, compared with 32.3, 20.6, and 21.3 in matched controls without multiple myeloma. Unadjusted mortality hazards ratios declined monotonically after 2004 to a value of 0.72; 95% confidence interval, 0.67 to 0.77 in 2009-2010, and declines between 2001-2002 and 2008-2009 were observed (P<0.05) in most demographic subgroups examined. Findings were similar when adjustment was made for demographic characteristics, comorbidity markers, and laboratory test values. These data suggest the incidence of RRT from multiple myeloma in the United States has decreased in the last decade, and clinically meaningful increases in survival have occurred for these patients.

Crystalloid podocytopathy with focal segmental glomerulosclerosis in PCM: a case report

Background

Crystalloid podocytopathy with focal segmental glomerulosclerosis in plasma cell myeloma (PCM) is rare.

Case Presentation

We present a case of crystalline deposition in the bone marrow (BM) and various renal cells with only proteinuria as a symptom. As workup for proteinuria, a renal biopsy sample was obtained. EM showed multiple crystalline depositions in renal tubular cells and podocytes. Focal segmental glomerulosclerosis with crystalloid podocytopathy was diagnosed. Because monoclonal gammopathy was detected in the serum and urine, a BM study was also performed. Plasma cells with needle-shaped inclusion bodies were observed. The crystalline deposits in the plasma cells and podocytes were positive for Masson’s trichrome and kappa light-chain staining. These findings indicated that the crystalline deposits originated from paraprotein. The case showed a rare process of focal segmental glomerulosclerosis via crystalline deposition in podocytes in plasma cell myeloma.

Conclusions

Crystalloid podocytopathy is a likely cause of renal damage such as FSGS in PCM, although it is an uncommon mechanism for myeloma kidney.

Combined IgG4κ and IgG1λ deposition in the glomerular and tubular basement membrane accompanied by autoimmune neutropenia (AIN) and immune thrombocytopenia (ITP)

A 48-year-old male was admitted to our hospital with nephrotic syndrome. Light-microscopic examination of a renal biopsy specimen showed almost normal glomerular appearance, however, immunofluorescence examination revealed linear and granular IgG deposits on the glomerular basement membrane (GBM), accompanied by slight IgG deposition in the tubular basement membrane (TBM). Further investigation of the IgG subclass and light chain staining revealed that the glomerular deposits were composed of IgG1 and IgG4, with both κ and λ light chains, while the tubular deposits were composed of only IgG4 and κ light chains. The electron-microscopic findings of small granular deposits in the GBM and TBM closely resembled those of light and heavy chain deposition disease (LHCDD). Immunoelectron microscopy confirmed the presence of κ and λ chains in the GBM and TBM, however, only significant κ chain deposition was found in the TBM. There was no evidence of monoclonal gammopathy. Clinically, the patient subsequently developed neutropenia and thrombocytopenia associated with the presence of anti-neutrophil antibody and anti-GPIIb/IIIa antibody-producing B cells in the blood. Oral steroid administration was initiated, which led to amelioration of the neutropenia, thrombocytopenia and proteinuria. This may be a very rare case of combined IgG4κ and IgG1λ deposition disease accompanied by autoimmune neutropenia (AIN) and immune thrombocytopenia (ITP) suggestive of biclonal immunoglobulin deposition disease (BIDD). Investigation of the IgG subclass and of the light chains was useful for recognizing the clonality of the immunoglobulin deposits in the kidney.

Pulmonary hypertension complicating multiple myeloma

Pulmonary hypertension (PH) is an infrequently reported complication of multiple myeloma (MM). PH has been more commonly associated with amyloidosis, myeloproliferative diseases, and the POEMS (polyneuropathy, organomegaly, endocrinopathy, monoclonal protein, skin changes) syndrome. PH in MM is typically mild to moderate and may be secondary to a variety of conditions, which include left ventricular dysfunction, high-output cardiac failure, chronic kidney disease, treatment-related toxicities, and precapillary involvement. We describe 3 patients with MM and severe PH. Each patient underwent right heart catheterization. All patients demonstrated elevated pulmonary pressures, transpulmonary gradients, and pulmonary vascular resistance. Each patient was ultimately treated with pulmonary vasodilator therapy with improvement in cardiopulmonary symptoms. Additional studies are needed to define the prevalence, prognosis, and pathogenesis of PH in this complex population and to help clarify who may benefit from targeted PH therapy.

Nonsecretory Multiple Myeloma and AL Amyloidosis Presenting with Nephrotic Range Proteinuria

Nonsecretory multiple myeloma (NSMM) is the absence of a detectable monoclonal protein in serum and urine of a multiple myeloma (MM) patient and immunoglobulin light chain (AL) amyloidosis is a significantly rare complication. A case of NSMM with AL amyloidosis and nephrotic range proteinuria is presented. Sharing clinical, therapeutic, and prognostic characteristics with MM, real challenge may be during initial diagnosis of NSMM and assessment of treatment response. In elderly patients with unexplained renal dysfunction, MM should be in the differential diagnosis and the absence of a monoclonal protein should not rule out MM but should remind us of the possibility of NSMM.

Shoulder pad sign and asymptomatic hypercalcemia in a patient with end-stage kidney disease

Interpreting an abnormal serum calcium level in subjects with chronic kidney disease (CKD) requires the simultaneous evaluation of various clinical and laboratory parameters. An excessive intake of calcium salts and vitamin D overdosing may be the most common etiologies of hypercalcemia in individuals with advanced CKD. Nevertheless, it should be noted that such patients are susceptible to all diseases that may cause hypercalcemia in subjects without renal disease. In this report, we describe the case of a male chronic hemodialysis patient who developed asymptomatic hypercalcemia associated with polyarticular swelling. On the basis of the findings of systemic workup, he was finally diagnosed as having multiple myeloma. The so-called shoulder pad sign, which is pathognomonic for light chain amyloidosis, although its detection remains a challenge for physicians, was a clue leading to the prompt diagnosis of the disease in the current case. The impact of articular manifestations on the diagnostic strategy for assessing multiple myeloma is also discussed.

New aspects on the pathogenesis of renal disorders related to monoclonal gammopathies

BACKGROUND

Multiple myeloma and other related monoclonal gammopathies are frequently encountered conditions associated with renal damage, especially in elderly population. They are arising from clonal proliferation of plasma cells in bone marrow producing various quantities of abnormal monoclonal immunoglobulins, or their components/fragments.

SUMMARY

These abnormal proteins differ from normal immunoglobulins in the amino acid sequence and in the three-dimensional structure of the molecule, which may determine their toxicity. Kidney seems to be a target organ as a major catabolic site. The pathology of renal disease is highly heterogeneous involving a variety of different mechanisms, which are divided into immunoglobulin dependent and immunoglobulin independent mechanisms. The Ig-dependent mechanisms may involve the four components of the kidney parenchyma, and the primary structure of these proteins determine the pattern of renal disease.

KEY MESSAGE

This review summarizes the existing literature in the pathobiology of multiple myeloma, and the pathological properties of the M-proteins, focusing on the mechanisms of the renal manifestations related to these abnormal proteins, especially glomerular injury. Also it supports the opinion that monoclonal gammopathy of undetermined significance (MGUS) should not be used in cases where there is proven renal impairment due to these proteins, even if it is mild and does not meet the current criteria.

Renal involvement in monoclonal gammopathy

Monoclonal gammopathy is produced by neoplastic or non-neoplastic expansion of a clone of plasma cells or B lymphocytes. Monoclonal gammopathy of unknown significance is characterized by low levels of the monoclonal protein and a relatively small population of clonal lymphocytes or plasma cells in the bone marrow. In these cases, the patient is asymptomatic with no evidence of overt myeloma or lymphoma. The abnormal serum protein may be present as a complete immunoglobulin molecule or may consist of ≥1 of its components such as light chains or heavy chains. These proteins may cause a variety of diseases in various tissues and organs, of which the kidney appears to be the most vulnerable. Renal involvement in monoclonal gammopathy may occur as part of a generalized disease such as amyloidosis, immunoglobulin deposition disease, and cryoglobulinemia. In addition, there may be evidence of kidney damage by processes which are renal specific. These include light chain proximal tubulopathy, light chain cast nephropathy, and a variety of glomerulopathies encompassing a wide spectrum of disease patterns.

A case of endocapillary proliferative glomerulonephritis with macrophages phagocytosing monoclonal immunoglobulin lambda light chain

Multiple myeloma (MM) is a plasma-cell neoplasm that can cause renal disorders. Renal lesions in MM can present with a very rare pathological manifestation involving a specific monoclonal immunoglobulin (Ig). We report the case of a 33-year-old woman who had edema, fatigue, elevated serum creatinine levels, hypoalbuminemia, and hypercholesterolemia. She had persistent hematuria and proteinuria lasting 3 years. Serum protein electrophoresis showed an M-spike, and serum immunofixation demonstrated the presence of monoclonal IgG λ. She had proteinuria in the nephrotic range, and a monoclonal λ fragment was present on urine immunofixation. Renal biopsy showed proliferative glomerulonephritis with λ light chain and C3c deposition and inflammatory cell infiltration with CD68. Macrophage lysosomes contained λ light chains, suggesting their partial phagocytosis. She was diagnosed with symptomatic MM and was treated with bortezomib and dexamethasone and an autologous peripheral stem cell transplant conditioned with intravenous melphalan. She achieved a partial response with decreased serum monoclonal protein and improved renal function. This case may be categorized as a monoclonal gammopathy-associated proliferative glomerulonephritis. The biopsy finding of partially phagocytosed Ig λ light chains by macrophages is very rare; this pathological condition is similar to crystal-storing histiocytosis.

Severe acute kidney injury and multiple myeloma: evaluation of kidney and patient prognostic factors

BACKGROUND

Patients with multiple myeloma (MM) manifesting acute kidney injury (AKI) and who later recover renal function and independence from renal replacement therapy (RRT) are considered to have a better outcome. The aim of this work was to study the factors associated with renal function recovery (independence of hemodialysis) and longer survival in these patients.

METHODS

A retrospective single center study including patients with a diagnosis of MM and severe AKI, defined as stage 3 of the Kidney Disease: Improving Global Outcomes (KDIGO) criteria: 3.0 times baseline increase in serum creatinine (sCr) or increase in sCr to ≥4.0mg/dL or initiation of RRT, was conducted. Data was registry-based and collected between January 2000 and December 2011. We examined demographic and laboratorial data, presenting clinical features, precipitating factors, need for RRT and chemotherapy. Death was considered the primary endpoint.

RESULTS

Lower serum β2-microglobulin was the only independent factor associated with recovery of renal function and independence of RRT (OR 0.95, 95% CI: 0.91-0.99, P=0.02). The median survival after AKI was 10.7±12.1months. The factors associated with longer survival were independence of RRT (HR 2.21; 95% CI: 1.08-4.49; P=0.02), lower CRP (HR 1.07; 95% CI: 1.03-1.12; P=0.001) and younger age (HR 1.03; 95% CI: 1.01-1.06; P=0.005).

CONCLUSIONS

Our study suggests that MM patients with lower serum β2-microglobulin have a higher likelihood of recovering renal function after severe AKI. Independence of RRT, lower CRP and younger age are associated with longer survival.

A case of Fanconi syndrome accompanied by crystal depositions in tubular cells in a patient with multiple myeloma

Fanconi syndrome (FS) is a rare condition that is characterized by defects in the proximal tubular function. A 48-year-old woman was admitted for evaluation of proteinuria. The patient showed normal anion gap acidosis, normoglycemic glycosuria, hypophosphatemia, and hypouricemia. Thus, her condition was compatible with FS. The M peak was found behind the beta globulin region in urine protein electrophoresis. Upon bone marrow examination, we found that 24% of cells were CD138+ plasma cells with kappa restriction. From a kidney biopsy, we found crystalline inclusions within proximal tubular epithelial cells. Thereafter, she was diagnosed with FS accompanied by multiple myeloma. The patient received chemotherapy and autologous stem cell transplantation, and obtained very good partial hematologic response. However, proximal tubular dysfunction was persistent until 1 year after autologous stem cell transplantation. In short, we report a case of FS accompanied by multiple myeloma, demonstrating crystalline inclusion in proximal tubular cells on kidney biopsy.

Future directions in the prevention of prostate cancer

The high global incidence of prostate cancer has led to a focus on chemoprevention strategies to reduce the public health impact of the disease. Early studies indicating that selenium and vitamin E might protect against prostate cancer encouraged large-scale studies that produced mixed clinical results. Next-generation prostate cancer prevention trials validated the impact of 5α-reductase inhibitors in hormone-responsive prostate cancer, and these results were confirmed in follow-up studies. Other interventions on the horizon, involving both dietary and pharmacological agents, hold some promise but require further investigation to validate their efficacy. In this Review, we discuss the clinical and preclinical evidence for dietary and pharmacological prevention of prostate cancer and give an overview of future opportunities for chemoprevention.

A novel rapid-onset high-penetrance plasmacytoma mouse model driven by deregulation of cMYC cooperating with KRAS12V in BALB/c mice

Our goal is to develop a rapid and scalable system for functionally evaluating deregulated genes in multiple myeloma (MM). Here, we forcibly expressed human cMYC and KRAS12V in mouse T2 B cells (IgM(+)B220(+)CD38(+)IgD(+)) using retroviral transduction and transplanted these cells into lethally irradiated recipient mice. Recipients developed plasmacytomas with short onset (70 days) and high penetrance, whereas neither cMYC nor KRAS12V alone induced disease in recipient mice. Tumor cell morphology and cell surface biomarkers (CD138(+)B220(-)IgM(-)GFP(+)) indicate a plasma cell neoplasm. Gene set enrichment analysis further confirms that the tumor cells have a plasma cell gene expression signature. Plasmacytoma cells infiltrated multiple loci in the bone marrow, spleen and liver; secreted immunoglobulins; and caused glomerular damage. Our findings therefore demonstrate that deregulated expression of cMYC with KRAS12V in T2 B cells rapidly generates a plasma cell disease in mice, suggesting utility of this model both to elucidate molecular pathogenesis and to validate novel targeted therapies.

Multiple myeloma and kidney disease

Multiple myeloma (MM) has a high incidence rate in the elderly. Responsiveness to treatments differs considerably among patients because of high heterogeneity of MM. Chronic kidney disease (CKD) is a common clinical feature in MM patients, and treatment-related mortality and morbidity are higher in MM patients with CKD than in patients with normal renal function. Recent advances in diagnostic tests, chemotherapy agents, and dialysis techniques are providing clinicians with novel approaches for the management of MM patients with CKD. Once reversible factors, such as hypercalcemia, have been corrected, the most common cause of severe acute kidney injury (AKI) in MM patients is tubulointerstitial nephropathy, which results from very high circulating concentrations of monoclonal immunoglobulin free light chains (FLC). In the setting of AKI, an early reduction of serum FLC concentration is related to kidney function recovery. The combination of extended high cutoff hemodialysis and chemotherapy results in sustained reductions in serum FLC concentration in the majority of patients and a high rate of independence from dialysis.

Late relapse of multiple myeloma presenting as a right atrial mass

Intracardiac involvement is a rare presentation of relapsed multiple myeloma. We present a case of lobulated mass in the wall of the right atrium, with extension to the inferior vena cava and obliteration and encasement of the interatrial septum in a 57-year-old man, a known case of multiple myeloma, with progressive exertional dyspnea and anasarca.

Clinical challenges: Myeloma and concomitant type 2 diabetes

Multiple myeloma is a malignant plasma cell disorder that accounts for approximately 10% of all hematological cancers. It is characterized by accumulation of clonal plasma cells, predominantly in the bone marrow. The prevalence of type 2 diabetes is increasing; therefore, it is expected that there will be an increase in the diagnosis of multiple myeloma with concomitant diabetes mellitus. The treatment of multiple myeloma and diabetes mellitus is multifaceted. The coexistence of the two conditions in a patient forms a major challenge for physicians.

A Rare Case of Renal Recovery in a Young Patient with Multiple Myeloma

Multiple myeloma (MM) is an uncommon hematologic malignancy accounting for 1% of all malignancies. Renal involvement is a common complication of MM. Rapid intervention to reverse renal dysfunction may be critical for management, especially in patients with light chain cast nephropathy. Recovery rate ranges from 5% to 15%. We describe an atypical presentation of MM in a young patient who presented with severe renal insufficiency requiring renal replacement therapy and achieved complete renal recovery with chemotherapy.

A Case of Light Chain Deposition Disease (LCDD) in a Young Patient

Light chain disease is a variant of multiple myeloma in which the malignant population of marrow cells produces free monoclonal light chains but no heavy chain or complete immunoglobulin. The monoclonal light chains are small enough to be freely filtered by the kidneys and become Bence-Jones protein. Light chain disease comprises about 18% of multiple myeloma patients. Here we present a case report of a 38-year-old man who initially presented with complaints of pain in back and low grade fever off and on. He was found to have collapse of D9 and D12 vertebrae along with ascites and right pleural effusion and massive proteinuria. Multiple myeloma was considered as a differential diagnosis based on the investigations but eventually the patient was lost to follow up. This case is reported here as the light chain variant of multiple myeloma leading to deposition disease is less commonly reported and presents considerable difficulties in diagnosis.

Amyloid proximal tubulopathy: a novel form of light chain proximal tubulopathy

Light chain proximal tubulopathy is a paraproteinemic-related kidney disease most commonly seen in patients with a plasma cell dyscrasia. The classic description is that of proximal tubules with kappa-restricted intracytoplasmic crystals in a patient with a clinical Fanconi’s syndrome. Recently, other variants of light chain proximal tubulopathy have been described including those without crystal formation. We expand the morphologic spectrum in this report of a patient who presented with acute renal failure, proteinuria and hematuria. Biopsy revealed proximal tubulopathy in which the proximal tubules show intracytoplasmic amyloid formation. This is the first description, to our knowledge, of amyloid proximal tubulopathy.

Multiple myeloma and diabetes

Multiple myeloma is a malignant plasma cell disorder that accounts for approximately 10% of all hematologic cancers. It is characterized by accumulation of clonal plasma cells, predominantly in the bone marrow. The prevalence of type 2 diabetes is increasing; therefore, it is expected that there will be an increase in the diagnosis of multiple myeloma with concomitant diabetes mellitus. The treatment of multiple myeloma and diabetes mellitus is multifaceted. The coexistence of the two conditions in a patient forms a major challenge for physicians.

Prognostic risk factor evaluation in patients with relapsed or refractory multiple myeloma receiving lenalidomide treatment: analysis of renal function by eGFR and of additional comorbidities by comorbidity appraisal

INTRODUCTION

Renal impairment (RI) is a dreaded complication in multiple myeloma (MM) and has been associated with decreased progression-free survival (PFS) and overall survival (OS).

METHODS

Forty-five consecutive patients with MM received lenalidomide therapy combined with either dexamethasone or standard chemotherapy, with dose modification according to current guidelines. Comorbidity indices (hematopoietic cell transplantation-specific comorbidity index [HCT-CI], Kaplan Feinstein [KF], and the Freiburg comorbidity index [FCI]) were analyzed and renal function was determined by estimated glomerular filtration rate (eGFR) before lenalidomide treatment and 1, 3, and 6 months after treatment.

RESULTS

The median patient age was 66 years. Pretreatment was substantial with ≥ 2 treatment lines in 71% of patients. Lenalidomide induced median PFS and OS of 13 and 25 months, respectively. The analysis of comorbidity scores identified only the FCI as significant, with different PFS for low-risk vs. high-risk patients of 20 vs. 9 months (p = .0036) and OS of not reached vs. 12.8 months (p < .0001), respectively. Although baseline renal function by serum creatinine evaluation appeared normal (median 1.0 mg/dL), mild RI was readily detectable by eGFR (median 83 mL/min/1.73 m(2)). When patients without RI were compared with those with mild, moderate, and severe RI, 1- and 2-year PFS rates were similar (hazard ratio [HR] with decreasing eGFR, 1.028; p = .6927). For OS, the HR of 1.192 indicated decreased survival probabilities with deteriorating eGFR (p = .0411), which was perceived by eGFR but not serum creatinine assessment (p = .2253).

CONCLUSIONS

Lenalidomide was well tolerated in intensively pretreated and elderly MM patients, including those with RI. PFS was not significantly different in patients with decreasing eGFRs, albeit RI and other comorbidities remained significant for OS.

Screening and differential diagnosis of renal light chain-associated diseases

BACKGROUND

Renal involvement in the light chain-associated diseases multiple myeloma (MM), amyloidosis (AL) and monoclonal immune position disease (MIDD) is common and differential diagnosis usually requires renal biopsy. The aim of this study was to investigate if noninvasive methods are viable to identify and differentiate between the various types of kidney diseases.

PATIENTS AND METHODS

All patients with a light chain-associated disease admitted to our center from 1996 to 2008 were retrospectively evaluated. Renal biopsy data were correlated with proteinuria findings.

RESULTS

Only the ratio of free κ/λ light chains showed a good sensitivity for myeloma cast nephropathy (MCN), AL and MIDD. The λ light chain was characteristic for AL, the κ light chain dominated in MIDD. Renal function at the time of diagnosis was worst in MIDD. MCN presented with a proteinuria of > 3.5 g/g creatinine. In contrast, a higher proteinuria was found in AL or MIDD. Whereas the κ/λ ratio in the urine was pathological for all three diseases, extremely high or low ratios indicated the presence of MCN. However, in AL or MIDD, the ratio was only moderately elevated.

CONCLUSION

A noninvasive differentiation between MCN and other forms of renal light chain disease is possible.

The pathogenesis and diagnosis of acute kidney injury in multiple myeloma

Renal failure remains a principal cause of morbidity for patients with multiple myeloma. Once reversible factors such as hypercalcemia have been corrected, the most common cause of severe renal failure in these patients is a tubulointerstitial pathology that results from the very high circulating concentrations of monoclonal immunoglobulin free light chains. These endogenous proteins can result in isolated proximal tubule cell cytotoxicity, tubulointerstitial nephritis and cast nephropathy (myeloma kidney). Less frequently, high levels of free light chains can lead to immunoglobulin light chain amyloidosis and light chain deposition disease, although these conditions are usually associated with insidious progression of renal failure rather than acute kidney injury. Unless there is rapid intervention, progressive and irreversible damage occurs, particularly interstitial fibrosis and tubular atrophy. Despite advances in our understanding of the pathogenesis of these processes there has been a gap in translating these achievements into improved patient outcomes. The International Kidney and Monoclonal Gammopathy Research Group was formed to address this need. In this Review, we discuss the mechanisms of disease and diagnostic approaches to patients with acute kidney injury complicating multiple myeloma.

The morphologic spectrum and clinical significance of light chain proximal tubulopathy with and without crystal formation

The renal diseases most frequently associated with myeloma include amyloidosis, monoclonal immunoglobulin deposition disease, and cast nephropathy. Less frequently reported is light chain proximal tubulopathy, a disease characterized by κ-restricted crystal deposits in the proximal tubule cytoplasm. Light chain proximal tubulopathy without crystal deposition is only loosely related to the typical light chain proximal tubulopathy, and little is known about this entity. A search was performed of the 10 081 native kidney biopsy samples processed by our laboratory over the past 2 years for cases that had light chain restriction limited to the proximal tubule cytoplasm. A total of 10 cases of light chain proximal tubulopathy without crystal deposition were found representing 3.1% of light chain-related diseases. Nine of these 10 showed λ-light chain restriction. Only three cases of light chain proximal tubulopathy with crystals were found accounting for 0.9% of light chain-related diseases. Two of these three were κ subtype. Plasma cell dyscrasia was unsuspected in seven of the 10 patients with light chain proximal tubulopathy without crystals at the time of renal biopsy. After the biopsy was reported, follow-up was available on 9/10 patients with 9/9 showing a plasma cell dyscrasia including 8/9 with multiple myeloma. We found that light chain proximal tubulopathy without crystal formation, despite being rarely described in the literature, is over three times more common than light chain proximal tubulopathy with crystal formation in our series. And given that it is often associated with previously unrecognized myeloma, it is a critically important diagnosis.

Evaluation of blood purification and bortezomib plus dexamethasone therapy for the treatment of acute renal failure due to myeloma cast nephropathy

Aggressive removal of circulating free light chains (FLC) by blood purification accompanied by chemotherapy is a promising approach for the treatment of acute renal failure due to myeloma cast nephropathy. Plasma exchange has been performed to remove serum FLC; in order to examine an alternative strategy we performed hemodiafiltration using protein-leaking dialyzers for the treatment of dialysis-dependent acute renal failure due to myeloma cast nephropathy. In the first case with κ-light chain cast nephropathy, the pre-treatment serum creatinine was 9.65 mg/dL, and the serum κ-FLC was 27100 mg/L. Plasma exchange or hemodiafiltration was performed from Monday to Friday during the first several weeks. Chemotherapy was started with high-dose dexamethasone and then switched to bortezomib plus dexamethasone. The mean removal rates of κ-FLC were 45.8% (one plasma volume) and 66.9% (one-and-a-half plasma volumes) by plasma exchange. The removal rates of κ-FLC by hemodiafiltration (66.9%, FB210UHβ; 71.6%, PES210Dα; 75.2%, FXS220) were comparable to those by plasma exchange. In the second case with λ-light chain cast nephropathy, the pre-treatment serum creatinine was 4.14 mg/dL, and the serum λ-FLC was 4140 mg/L. The mean removal rates of λ-FLC were 60.2% (FXS140) and 64.2% (FB210UHβ) by hemodiafiltration. Both cases became dialysis-independent. The combination of an intense blood purification regimen and bortezomib plus dexamethasone therapy appears to be an efficient approach to renal recovery. Hemodiafiltration using protein-leaking dialyzers could become an alternative to plasma exchange as a method of removing FLC.

Ig-related renal disease in lymphoplasmacytic disorders: an update

Ig-related renal diseases occurring in lymphoplasmacytic disorders (LPD) cover a wide spectrum of renal lesions. Except for cast nephropathy, which is almost specific for multiple myeloma, similar renal lesions caused by deposition or precipitation of monoclonal Ig-related material may occur in the various types of LPD. Because the secreted Ig provides the link between the LPD and the kidney disease, the renal outcome is linked to efficacy of chemotherapy. In the past 10 years, considerable advances have occurred in chemotherapy regimens with the advent of new classes of drugs, which already result in markedly improved renal and vital survival.

Renal failure caused by plasma cell infiltration in multiple myeloma

We report on a case of severe renal failure in a 61-year-old female with multiple myeloma (MM). Two months prior to admission, the patient was diagnosed to have anemia and progressive renal failure associated with urinary Bence Jones protein and was referred to our hospital. A bone marrow biopsy revealed 40% plasma cells with κ light chain restriction. Thus, she was considered to have MM. A renal biopsy revealed neoplastic plasma cell infiltration within the kidney, moderate interstitial fibrosis, tubular atrophy, and punctate, electron-dense material along the peripheral capillary walls, tubular basement membrane, and in the interstitium of the kidney. This suggested that a combination of compression of the tubules and the microvasculature by the infiltrative process, and local light chain deposition-mediated tissue damage might be implicated in the development of renal failure in this patient. Despite a remission of bone marrow plasmacytosis with a bortezomib-based regimen, her renal function gradually deteriorated and a periodic hemodialysis program was finally required. Although the clinical impact of the direct kidney infiltration of neoplastic plasma cells on the longitudinal changes in renal function remains to be delineated, it is reasonable to consider that the infiltration of neoplastic plasma cells associated with local light chain depositions may result in irreversible renal injuries. Obviously, further studies and accumulation of additional experience with renal biopsy are required to better determine the precise and prognostic relationship between renal outcome and morphological alterations among MM patients with varying degrees of renal impairment.

A Novel Transgenic Mouse Model of the Human Multiple Myeloma Chromosomal Translocation t(14;16)(q32;q23)

Multiple myeloma (MM) is a currently incurable neoplasm of terminally differentiated B cells. The translocation and/or overexpression of c-MAF have been observed in human MM. Although c-MAF might function as an oncogene in human MM, there has been no report thus far describing the direct induction of MM by c-MAF overexpression in vivo. In this study, we have generated transgenic (TG) mice that express c-Maf specifically in the B-cell compartment. Aged c-Maf TG mice developed B-cell lymphomas with some clinical features that resembled those of MM, namely, plasma cell expansion and hyperglobulinemia. Quantitative RT-PCR analysis demonstrated that Ccnd2 and Itgb7, which are known target genes of c-Maf, were highly expressed in the lymphoma cells. This novel TG mouse model of the human MM t(14;16)(q32;q23) chromosomal translocation should serve to provide new insight into the role of c-MAF in tumorigenesis. Cancer Res; 71(2); 339–48. ©2011 AACR.

The efficacy and safety of lenalidomide plus dexamethasone in relapsed and/or refractory multiple myeloma patients with impaired renal function

BACKGROUND:

In patients with multiple myeloma, renal impairment (RI) at the time of diagnosis is associated with poor survival. To the authors' knowledge, the current retrospective analysis presented is the first to assess the impact of various degrees of renal dysfunction on safety and efficacy outcomes in a large cohort of patients with relapsed and/or refractory multiple myeloma who received treatment with lenalidomide plus dexamethasone.

METHODS:

Three hundred fifty-three patients from 2 large phase 3 trials were randomized to receive lenalidomide (25 mg) plus dexamethasone (40 mg). For the purpose of this analysis, RI was defined according to the calculated creatinine clearance (CL_Cr) level as follows: mild or no RI (CL_Cr ≥ 60 mL/minute), moderate RI (CL_Cr from ≥ 30 mL/minute to <60 mL/minute), and severe RI (CL_Cr <30 mL/minute).

RESULTS:

The RI subgroups did not differ significantly in terms of the overall response rate (range, 50%-64%) or response quality (very good partial response or better, 27%-37%). In all RI subgroups, the time to progression and progression-free survival did not differ significantly compared with the mild or no RI group. Patients with RI experienced an increased incidence of thrombocytopenia, required more frequent lenalidomide dose reduction or interruption, and had shorter overall survival than patients with mild or no RI (P = .006). Lenalidomide plus dexamethasone led to improvement in renal function in the majority of patients.

CONCLUSIONS:

The results from this study indicated that, with careful monitoring of the CL_Cr level and adverse events as well as appropriate dose adjustments, lenalidomide plus dexamethasone is an effective and well tolerated treatment option for patients with multiple myeloma who have RI. Cancer 2010. © 2010 American Cancer Society.

[Kidney involvement in hematologic malignancies. Diagnostic approach]

Kidney involvement is frequent in hematologic malignancies. It is associated with adverse outcome and treatment difficulties. It can affect every area of the renal parenchyma (tubules, interstitium, glomerulus, vessels). Various mechanisms could be implicated: deposits of immunoglobulin fractions or crystals, renal infiltration by malignant cells, urinary tract obstruction, paraneoplastic or storage glomerulopathies… Diagnostic strategy relies on the clinical presentation: acute renal failure, chronic kidney disease, glomerular proteinuria with or without nephrotic syndrome, tubular proteinuria, hydroelectrolytic disorders. In this review, we detail the diagnostic tests that are needed for the detection and the follow-up of renal involvement in hematologic malignancies, and clarify the indications of renal biopsy. We propose diagnostic strategies of renal involvement in myeloma, Waldenström's disease, high grade lymphomas and acute leukemias, low grade lymphomas and chronic leukemias. The adverse effects of treatments (chemotherapy, radiotherapy, stem cell graft …) are not addressed in this review.

Light chains: heavy burden in kidney transplantation

Plasma cell dyscrasias are frequently encountered malignancies which are often associated with kidney disease through the production of monoclonal immunoglobulin (Ig). Recent advances in the field include the availability of an assay for free light chains, the introduction of new agents which more effectively target malignant plasma cells, and refinements in the application of stem-cell transplantation. Well-selected patients with plasma cell dyscrasias whose monoclonal Ig is well controlled may be candidates for kidney transplantation. Kidney transplant patients with allograft dysfunction from recurrent or de novo monoclonal Ig deposition can be successfully identified and treated with these new approaches.

Renal lesions associated with plasma cell dyscrasias: practical approach to diagnosis, new concepts, and challenges

CONTEXT

Patients with plasma cell dyscrasias (myeloma) may exhibit a variety of renal manifestations as a result of damage from circulating light- and heavy-chain immunoglobulin components produced by the neoplastic plasma cells. The renal alterations can occur in any of the renal compartments, and in a significant number of the cases more than one compartment is affected. Research in the laboratory has helped considerably in providing a solid conceptual understanding of how renal damage occurs.

OBJECTIVES

To detail advances that have been made in the diagnosis of these conditions and to provide an account of research accomplishments that have solidified diagnostic criteria. The new knowledge that has been acquired serves to provide a solid platform for the future design of new therapeutic interventions aimed at ameliorating or abolishing the progressive renal damage that typically takes place.

DATA SOURCES

Translational efforts have substantially contributed to elucidate mechanistically the molecular events responsible for the renal damage. The spectrum of renal manifestations associated with plasma cell dyscrasias has expanded significantly in the last 10 years. Diagnostic criteria have also been refined. This information has been summarized from work done at several institutions.

CONCLUSIONS

A number of significant challenges remain in the diagnosis of these conditions, some of which will be discussed in this article. Dealing with these challenges will require additional translational efforts and close cooperation between basic researchers, clinicians, and pathologists in order to improve the diagnostic tools available to renal pathologists and to acquire a more complete understanding of clinical and pathologic manifestations associated with these conditions.

Treatment of patients with myeloma with comorbid conditions: considerations for the clinician

Patients with multiple myeloma (MM) frequently present with serious comorbidities such as renal impairment and/or diabetes. Treatment of these patient subsets poses a greater challenge: renal dysfunction can alter drug clearance leading to increased toxicity, and commonly used regimens can induce or exacerbate hyperglycemia. In recent years, novel targeted therapies have broadened and improved treatment options for all patients with MM. With these advancements, clinical trials are beginning to report benefit in patients with renal impairment. Furthermore, steroid-sparing and steroid-free regimens have proven highly efficacious and are predicted to improve options for patients with diabetes. This review will highlight recent trials evaluating novel regimens that promise to improve the standard of care for patients with MM with significant comorbidity.