Proliferative glomerulonephritis with monoclonal immunoglobulin deposits in a kidney allograft.

Paraprotein may accumulate in glomeruli and cause kidney damage associated with variable histopathologic patterns and a characteristic immunofluorescence staining restricted to a single light chain and/or a single heavy chain isotype. Hence, such glomerular injury includes diseases caused by deposition of a monoclonal light chain, heavy chain, or entire immunoglobulin (light and heavy chains), which may manifest as proliferative glomerulonephritis. In this report, we focus on the latter as the least characterized of the 3, particularly in the transplantation setting. We describe a case of late transplant dysfunction associated with glomerular immunoglobulin G1/κ deposits. We also present our experience with proliferative glomerulonephritis and monoclonal immunoglobulin deposits in transplant and native kidney biopsies, with reference to the literature.