[Membranous nephropathy with nephrotic syndrome developed after allogeneic hematopoietic stem cell transplantation for acute lymphoblastic leukemia].

A 38-year-old man was diagnosed with acute lymphoblastic leukemia. We performed myeloablative bone marrow transplantation from an unrelated donor during the patient's first complete remission. After engraftment, he developed acute graft-versus-host disease involving the gastrointestinal tract on day 32. Steroids and mycophenolate mofetil were initiated from day 39. His symptoms improved and the dose of immunosuppressants was tapered and then discontinued on day 421. On day 491, he developed nephrotic syndrome (NS). Based on renal biopsy, membranous nephropathy was diagnosed. There were no apparent symptoms or abnormal laboratory data suggestive of chronic graft-versus-host disease (cGVHD). Steroid therapy was initiated from day 518 and proteinuria improved significantly. NS is very rare following allogeneic hematopoietic stem cell transplantation (allo-HSCT). When there is no concomitant cGVHD, as in this case, allo-HSCT-associated NS is difficult to distinguish from idiopathic NS.

[Epstein-Barr virus-associated post-transplant lymphoproliferative disorder diagnosed by the episode of intestinal perforation following allogeneic hematopoietic stem cell transplantation].

A 64-year-old man was diagnosed as having acute myeloid leukemia. We performed sequential treatment with chemotherapy and reduced-intensity stem cell transplantation from an unrelated donor while the patient was in partial remission. After engraftment, he developed acute graft-versus-host disease of the gut on day 42 and steroid therapy was started. Despite transient aggravation of diarrhea, his symptoms slowly improved and the dose of steroid was tapered. On day 159, he complained of acute left lower abdominal pain. A CT scan showed perforation of the digestive tract and ileectomy was performed. At surgery, multiple ulcers of the intestine were found and one of the ulcers was perforated. Pathologically, transmural and diffuse proliferation of atypical cells in the ulcer were confirmed. Since these cells were positive for CD20 and Epstein-Barr-virus (EBV) encoded RNA, we made a diagnosis of EBV-associated post-transplant lymphoproliferative disorder (PTLD). Reduction in the dose of immunosuppressive agents and rituximab led to complete remission of PTLD. PTLD after allogeneic hematopoietic stem cell transplantation (allo-HSCT) is relatively rare, and the development of gastrointestinal perforation after allo-HSCT is very rare.