Crystalglobulin-Induced Nephropathy and Cardiac Nonamyloidotic Immunoglobulin Deposition Disease: A Fatal Case Report.

Crystalglobulin-induced nephropathy (CIN) is a rare renal disorder associated with multiple myeloma, characterized by crystal-induced damage in multiple organs, with diagnosis based on the identification of crystals within affected tissues. Conversely, cardiac nonamyloidotic immunoglobulin deposition disease (CIDD) involves the deposition of nonamyloid light chains in the myocardium. In this study, we report a case of CIN combined with CIDD in a 55-year-old woman. Renal biopsy revealed crystalline structures within the interlobular artery, which stained positive for immunoglobulin G1 and lambda chains on fluorescent antibody analysis. Immunoelectron microscopy confirmed the deposition of lambda light chains within the crystalline structures. Fluorescent antibody staining demonstrated lambda-chain deposition in the skin, duodenum, and cardiac tissue. The patient was diagnosed with CIN and chemotherapy was initiated. However, the patient died owing to acute renal failure and rapidly progressive cardiac dysfunction. Autopsy findings revealed no crystalline structures in the myocardium, suggesting an association between CIN and CIDD. Reports on CIN are scarce, and its pathogenesis remains poorly understood. CIDD is also rare, and to date, no previous reports have described concurrent CIN and CIDD with such an abrupt clinical course. Early diagnosis and prompt therapeutic intervention are necessary.