Proliferative glomerulonephritis with monoclonal IgM deposits without Waldenstrom s macroglobulinemia: case report and review of the literature #MMPMID22377259
Yahata M; Nakaya I; Takahashi S; Sakuma T; Sato H; Soma J
Clin Nephrol 2012[Mar]; 77 (3): 254-60 PMID22377259show ga
A 38-year-old man was presented with nephrotic syndrome associated with hematuria and mild hypocomplementemia. Renal biopsy revealed lobular mesangial proliferation, thickened capillary walls, and intraluminal protein thrombi. Immunofluorescence showed marked and mild depositions of immunoglobulin (Ig) M heavy chains and complement C3, respectively, in a peripheral lobular pattern. On light chain staining, only kappa (kappa) light and IgM heavy chains showed a similar pattern. Electron microscopy showed fine granular electrondense deposits in subendothelial areas and numerous globular deposits (varying size and density) in glomerular capillary lumens. Serum levels of Ig kappa, but not of free kappa, light chains were significantly increased. Bone marrow aspiration revealed a normocellular marrow. Waldenstrom's macroglobulinemia and cryoglobulinemia were ruled out. Clinically, steroid therapy was ineffective and proteinuria persisted. This report demonstrates that glomerular deposition of monoclonal IgM-kappa can produce membranoproliferative- like changes in the glomeruli. This condition may be recognized as proliferative glomerulonephritis with monoclonal IgM deposits similar to the recently recognized proliferative glomerulonephritis with monoclonal IgG deposits.
Clin+Nephrol 2012 ; 77 (3): 254-60
