A case report of thrombotic thrombocytopenic purpura and severe acute renal failure post non-myeloablative allogeneic peripheral blood stem cell transplantation treated with plasma exchange and hemodialysis.

A 59-year-old-woman received related non-myeloablative allogeneic peripheral blood stem cell transplantation (PBSCT) subsequent to autologous PBSCT in our hospital five years after she was diagnosed as oligo-secretory myeloma. She was admitted to our hospital because of vomiting and grayish diarrhea 4 months after non-myeloablative allogeneic PBSCT (mini-alloPBSCT). Although her initial symptoms improved after admission, she gradually showed thrombocytopenia, anemia, and oliguria during the 2 weeks after admission. Our diagnosis was thrombotic thrombocytopenic purpura (TTP) and acute renal failure (ARF) secondary to mini-alloPBSCT. After cessation of cyclosporine administration, we began to treat her with plasma exchange (PE) and hemodialysis. During the three and a half months after we started PE, the TTP gradually improved. Although PE had been reported to be ineffective for TTP post bone marrow transplantation, we could finally discontinue PE. In contrast, since her anuria continued, she was managed with hemodialysis. One month after PE was started, her activity of von Willebrand factor-cleaving protease was 41% (normal range, >50%) and the ultrasonographic investigation of both kidneys was normal. She could be discharged after four and a half months hospitalization and lived well as an outpatient for a further two months. She died shortly after readmission from multiple organ failure without the relapse of TTP. The patient's clinical course would suggest that TTP post mini-alloPBSCT could be treated with PE in some cases, despite the development of dialysis-requiring severe ARF being a poor prognostic factor.