Cryoglobulinemia in a moroccan nephrology department

Cryoglobulinemia is a rare cause of kidney disease that occurs in patients with various diseases. Renal involvement often occurs after appearance of various clinical manifestations dominated by purpura and neuropathy. The aim of this study is to describe clinical, biological, and pathological characteristics of cryoglobulinemic glomerulonephritis (GN), as well as treatment and outcome. This is a retrospective study including all patients with positive cryoglobulin test and biopsy-proven GN secondary to cryoglobulinemia. Fourteen patients with cryoglobulinemic GN were collected. Their mean age was 46.92 ± 15.82 years with male predominance (64.28%). Weight loss, fever (71.42%), and purpuric rash (57.14%) were the main extrarenal manifestations. Eight patients presented with nephrotic syndrome (NS), associated with renal impairment in three patients. Four patients had rapidly progressive GN and two patients had acute kidney injury. Renal biopsy, performed in all patients, revealed membranoproliferative GN with glomerular thrombi in all patients. Crescents and necrotizing vasculitis were present in four patients. Hepatitis C virus (HCV) infection was the most common etiology. Antivirals and steroids or other immunosuppressive agents were used in most of the patients. During follow-up, complete response was observed in three patients and partial response was observed in four patients. Five patients had no response with renal injury requiring hemodialysis. NS with hematuria and renal insufficiency were the main clinical manifestations of cryoglobulinemic GN. In our study, HCV infection dominated the etiologies, although not well described earlier. A half of our patients had poor outcome even after antiviral and immunosuppressive therapy.