Massive post-transplant proteinuria with minimal histological changes.

Three patients developed massive proteinuria, hypoalbuminemia, and edema after transplantation. These findings occurred in the immediate post-transplant period in two patients, and renal failure developed. The third patient developed proteinuria 4 months post-transplantation. There was complete remission of proteinuria in two patients and recovery of renal function in one. Renal histology was similar in all. Light microscopy demonstrated that the glomeruli contained a mild increase in mesangial matrix, but were otherwise normal. No significant interstitial cellular infiltration or fibrosis was present. Immunofluorescence microscopy revealed no staining for immunoglobulins or complement. Electron microscopy demonstrated fusion of foot processes, but the glomerular basement membrane was normal. No electron-dense deposits were found. The usual causes of post-transplant nephrotic syndrome were ruled out. We believe these three patients represent a unique disorder of the transplanted kidney.