A case of recurrent focal segmental glomerulosclerosis (FSGS) involving massive proteinuria (>50 g/day) immediately after renal transplantation.

A 15-yr-old girl with end-stage kidney disease caused by primary focal segmental glomerulosclerosis (FSGS) underwent a living-related donor kidney transplantation. The allograft functioned well immediately after reperfusion, but massive proteinuria exceeding 50 g/d appeared on day 3. Treatment with rituximab and plasma exchange (PE) successfully decreased the proteinuria to 10 g/d. A biopsy specimen on day 30 showed no segmental glomerulosclerosis but partial interstitial infiltration of inflammatory cells. An increased number of podocytes showed intracytoplasmic vacuolization, and an electron micrograph showed diffuse mild subendothelial edema and foot process effacement. The podocytes were hypertrophied but were not detached from the basement membrane. As the therapies used to reduce the patient's proteinuria were having a limited effect, intravenous steroid pulse therapy followed by low-density lipoprotein apheresis was performed. A biopsy specimen taken on day 120 showed no segmental glomerulosclerosis. Thrombus formation in one glomerulus and packed lymphocytes in the capillary loop of another glomerulus were detected. The patient's clinical course was compatible with FSGS recurrence. Although the early pathological changes were not typical of FSGS, they might be indicative of the primary lesion that subsequently progresses to typical FSGS.