Tu107 - Cryoglobulinemic Glomerulonephritis in the Setting of Multiple Myeloma: A Rare Clinical Presentation

Abstract Text: Multiple myeloma (MM) is a plasma cell disorder producing monoclonal immunoglobulins, leading to skeletal destruction and renal failure. Cryoglobulinemia is a systemic inflammatory disorder that involves cryoglobulin deposition in small to medium sized vessels. In multiple myeloma, monoclonal immunoglobulins may behave as cold-induced cryoglobulins, causing vascular obstruction. We report a case of multiple myeloma manifesting as Type I cryoglobulinemic glomerulonephritis (T1C) with IgG2 kappa cryoglobulin (IgG2-K).

A 74-year-old male with chronic kidney disease (CKD), hypertension, hyperlipidemia, rheumatoid arthritis (RA), monoclonal gammopathy of undetermined significance (MGUS), and seizure disorder presented with hypertensive urgency, shortness of breath, and severe renal dysfunction (Creatinine - 10). PET CT revealed lytic bone lesions and no evidence of renal obstruction. Renal biopsy confirmed Type I cryoglobulinemic vasculitis (IgG2-K). Due to multiple lytic lesions, renal involvement, and a history of MGUS, bone marrow biopsy was performed revealing MM. The patient was initiated on DaraCyBorD and later taken off dialysis with profound renal recovery. He continues with DaraCyBorD outpatient with clinical improvement

MM that presents as T1C is rare, particularly in patients with pre-existing comorbidities. Diagnostic challenges included confounding conditions, such as MGUS-related renal failure and RA-associated renal amyloidosis. Additionally, the absence of classic cryoglobulinemia findings, such as arthralgia or purpura, further obscured the diagnosis. Although there have been multiple reports of IgGG3 cryoglobulinemic glomerulonephritis, IgGG2 CGN is exceptionally rare.

This case underscores the importance of recognizing atypical presentations of multiple myeloma such as this one that manifested as T1C glomerulonephritis.