A Rare and Atypical Case of Essential Cryoglobulinemic Glomerulonephritis with Crescents

Abstract

We report a rare and atypical case of essential cryoglobulinemic glomerulonephritis with crescent formation in an 18yo African-American male that presented with recurrent microscopic hematuria, proteinuria, and mildly elevated creatinine. There was no antecedent history of purpura, rashes, or arthralgia/ myalgia, and autoantibodies as well as viral serology for HCV, HIV, and CMV were negative. Quantification of serum immunoglobulins was significant for an elevated IgM without the presence of rheumatoid factor and elevated kappa and lambda light chains. Kidney biopsy demonstrated sclerosis, interstitial inflammation, endocapillary and mesangial proliferation, and crescent formation. Immunofluorescent studies demonstrated granular deposits within the glomerular basement membrane and mesangium. Electron microscopy revealed podocyte foot process effacement and the presence of mesangial and subendothelial electron dense deposits of randomly arranged, slightly curved microtubular/ fibrillary structures that formed occasional fingerprints consistent with a diagnosis of cryoglobulinemic glomerulonephritis. The diagnosis was confirmed by the identification of serum cryoglobulins with subsequent immunofixation electrophoresis of the cryoprecipitate revealing a mixed cryoglobulinemia type III. Treatment with IV methylprednisolone, followed by oral prednisone and Rituximab was initiated with resolution of hematuria and normalization of creatinine.