Membranous glomerulonephritis--an under-reported histological finding in multiple myeloma

Synchronous Presentation of Autoimmune Hepatitis and Multiple Myeloma

Autoimmune hepatitis (AIH) is a rare immune-mediated disease predominantly seen in women and triggered by various environmental factors. Rarely, AIH can be triggered by an underlying malignancy. We report a woman in her 60s who presented with markedly abnormal liver biochemical tests. Serology was positive for anti-smooth muscle antibodies and a liver biopsy confirmed AIH. During the hospital course, she developed sepsis and acute renal failure requiring dialysis support. Serum protein electrophoresis (SPEP) showed a monoclonal IgG kappa protein of 1.92 g/dL and a bone marrow biopsy revealed 7% clonal plasma cells. She had lytic lesions on skeletal survey confirming the diagnosis of a coexisting multiple myeloma (MM). Given her markedly abnormal liver chemistries, we decided to treat the AIH first and use the steroids (an important anti-myeloma therapy) as a bridge to the specific treatment of the MM once her clinical condition improved. She was treated with oral prednisone and azathioprine for AIH. One month later, a marked improvement in liver biochemical test results was noted and she was started on oral ixazomib, lenalidomide and dexamethasone. She received palliative radiotherapy to the lumbar spine (L2), left femur, and ischium lesions. This case highlights a rare co-occurrence of AIH and MM, the underlying mechanism of which is unknown.

Proliferative glomerulonephritis with monoclonal immunoglobulin deposits: a nephrologist perspective

Proliferative glomerulonephritis (GN) with monoclonal immunoglobulin deposits (PGNMIDs) is a recently described entity among the spectrum of monoclonal gammopathy of renal significance (MGRS). The disease is renal limited and manifests with chronic glomerular disease, altered renal function and albuminuria, sometimes in the nephrotic range. Acute nephritic syndrome is rare. PGNMID occurs mostly in the sixth decade, but it may affect young adults. Histologically, PGNMID is characterized predominantly by membranoproliferative GN and less frequently by diffuse endocapillary GN, mesangioproliferative GN or atypical membranous GN. Immunofluorescence and electron microscopic studies are the cornerstone of diagnosis, showing granular deposits involving glomeruli only, and composed of monotypic immunoglobulin G (IgG), with a single heavy chain subclass (most commonly IgG3) and light chain (LC) restriction (usually κ), admixed with complement deposits. PGNMID variants with monotypic LC-only, IgA or IgM deposits are uncommon. Ultrastructurally, deposits are amorphous with predominant subendothelial and mesangial distribution. PGNMID should be distinguished from type 1 cryoglobulinemic GN and immunotactoid GN, which share some common pathological features. Contrary to other MGRS lesions, the rate of detection of the nephrotoxic monoclonal Ig in the serum or urine, and of an abnormal bone marrow B-cell clone, is only ∼30%. Renal prognosis is poor, with progression to end-stage renal disease in 25% of patients within 30 months and frequent early recurrence on the renal allograft. The pathophysiology of PGNMID is unclear and its treatment remains challenging. However, recent studies indicate that clone-targeted chemotherapy may significantly improve renal outcomes, opening future perspectives for the management of this rare disease.

Autoimmune manifestations in patients with multiple myeloma and monoclonal gammopathy of undetermined significance

Background

Multiple myeloma (MM) and its precursor, monoclonal gammopathy of undetermined significance (MGUS), have been linked with several autoimmune conditions in the medical literature. Yet, significance of these associations is not well understood.

Methods

Herein, we provide a comprehensive literature review on autoimmune disorders identified in patients with MM and MGUS. Most relevant papers were identified via searching the PubMed/Medline and EMBASE databases for articles published from inception until May 1, 2016.

Findings

Scientific literature on autoimmune conditions in patients with MM and MGUS consists of several case series and a multitude of case reports. Our analysis suggests an increased prevalence of autoimmune conditions in patients with MM and monoclonal gammopathy of undetermined significance (MGUS), including various autoimmune hematologic and rheumatologic conditions among other entities. Conversely, persons with various autoimmune conditions tend to have a higher prevalence of MGUS and MM than the general population.

Conclusions

Future research is required to explore further the link between MGUS/MM and autoimmune disorders. Inflammation in the setting of autoimmunity may serve as a trigger for MGUS and MM. In addition, a common genetic susceptibility for developing both an autoimmune disease and MM/MGUS might also exist. Autoimmune hematologic and rheumatologic diseases may pose important clinical problems for the MM patients. Therefore, a catalogue of these problems is important so that physicians are able to consider, identify and address them promptly.

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A comprehensive review linking MM and MGUS with autoimmune disorders

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There is increased prevalence of autoimmune conditions in patients with MM and MGUS

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Most autoimmune disorders precede the development of plasma cell dyscrasias

Coexisting glomerular IgA deposition and IgG-kappa multiple myeloma

Multiple myeloma (MM) is a common malignancy that often results in many kinds of kidney injuries for the abnormal monoclonal immunoglobulin. Here, we present an IgG-kappa type MM case accompanied by renal IgA deposition combined with IgG-kappa. The patient was treated with prednisone plus mycophenolate mofetil, and got a satisfactory remission. Although it cannot be determined whether the IgA deposition was secondary to MM, this was the first report of coexisting mesangial proliferative nephritis with IgA deposition and IgG-kappa type MM.