[A case of focal segmental glomerulosclerosis with nephrotic syndrome after hematopoietic stem cell transplantatation for aplastic anemia].

We report a case of pediatric severe aplastic anemia (SAA), where the patient underwent allogenic bone marrow transplantation (BMT) from an HLA mismatched family donor and developed focal segmental glomerulosclerosis (FSGS). An 11-year-old girl, who had SAA, was admitted to our hospital in 200X. Complete remission was not attained after immunosuppressive therapy with rabbit-antithymocyte globulin, prednisolone (PSL), and cyclosporine A (CsA). Eight months after being diagnosed with SAA, she underwent an allogenic BMT from her mother. We used a combination of 2-Gy total body irradiation, fludarabine, and cyclophosphamide as a preparative regimen prior to the BMT. CsA and PSL were used as prophylaxis against GVHD. Since the BMT did not lead to successful engraftment, the patient required two peripheral blood stem cell transplantations (PBSCT). Engraftment was sustained and no acute or chronic GVHD was observed. Six months after the first BMT, she developed clinical nephrotic syndrome despite the continuous PSL and CsA treatments. Renal biopsy revealed a total of 12 glomeruli, one of which showed segmental sclerosis. Electron microscopy revealed diffuse effacement of the foot processes. These findings were consistent with FSGS, and she was treated with mycophenolate mofetil (MMF) in combination with PSL instead of CsA, which greatly reduced her proteinuria. In general, the most common type of nephropathy after HSCT is GVHD-related nephrotic syndrome, and the most common pathological finding is membranous nephropathy or minimal change. FSGS without GVHD after HSCT, such as that observed in our case, is rare. In this case, the renal damage appears to have been caused by the effect of circulating permeability factors with immunity change after HSCT. This case demonstrates the importance of renal biopsy as a guide to determine the extent of renal damage and as an aid to determine the possible response to therapy.