Light chain deposition disease in a postrenal transplant patient

The morphological spectrum of light chain deposition disease (LCDD) may range from normal glomerular morphology to mesangio-proliferative to mesangio-capillary to nodular sclerosing patterns. Due to the inconsistencies regarding treatment and the universally poor graft outcome of post-transplant LCDD, it is imperative to maintain a high index of suspicion and perform relevant investigations for clinching this diagnosis. A 40-year-old lady was diagnosed as a case of membrano-proliferative glomerulonephritis 3 years back, for which she underwent a live unrelated renal allograft transplant. Postoperative period was complicated by an acute rise in serum creatinine on the 21(st) postoperative day. Biopsy showed patchy acute cortical necrosis, which responded to conservative management. The present admission was for renal failure and subnephrotic proteinuria. A kidney biopsy was performed, and all the 14 glomeruli examined showed a mesangiocapillary pattern of glomerular injury with cellular nodule formation in some. The nodules were PAS and Congo red negative. Immunofluorescence showed glomerular and tubular basement staining for Kappa light chains only. Electron microscopy showed the characteristic granular deposits in subendothelial location in the glomerulus, and in tubular basement membranes, thus confirming the diagnosis of LCDD. Membranoproliferative pattern of glomerular injury in the pre- and posttransplant setting has a wide range of differential diagnoses; LCDD being one of them.