Heat-insoluble cryoglobulin in a patient with essential type II cryoglobulinemia and cryoglobulin-occlusive membranoproliferative glomerulonephritis: Case report and literature review

Background: A type of heat-insoluble cryoglobulin has been rarely reported and poorly understood. We report the case of a 79 y-old female who was admitted to hospital due to edema and renal failure. Methods: Serial biochemical, immunological, and histological investigations were conducted. Results: This patient had elevated serum urea and creatinine with positive rheumatoid factor and low serum C3 and C4. Her serum was positive for cryoglobulin at 4 degrees C. The precipitate did not dissolve at 37 degrees C until it was heated to 56 degrees C. Electrophoresis of the cryoglobulin demonstrated a monoclonal spike in the gamma region characterized as IgG-kappa and polyclonal IgM by immunofixation. Bone marrow aspiration showed presence of 5% plasma cells. Histological examination of renal biopsy revealed a diffuse increase in mesangial matrix, cellularity and endocapillary proliferation. Numerous monocyte/macrophages were present within mesangium and capillary lumina. Focal double contouring of glomerular basement membrane with subendothelial deposits and "hyaline thrombi" were noted. Accordingly, a type 11 heat-insoluble cryoglobulinemia associated with membranoproliferative glomerulonephritis and monoclonal gammopathy of undetermined significance was made. Conclusions: The unusual heat-insoluble cryoglobulins may indicate severe clinical consequence. Proper laboratory procedure and careful examination of cryoglobulin will assure early recognition and detection of heat-insoluble cryoglobulins. (C) 2009 Elsevier B.V. All rights reserved.