Intestinal thrombotic microangiopathy following reduced-intensity umbilical cord blood transplantation

Thrombotic microangiopathy ( TMA) is a significant complication after hematopoietic stem-cell transplantation (HSCT); however, there is little information on it following reduced-intensity cord blood transplantation (RI-CBT). We reviewed the medical records of 123 adult patients who received RI-CBT at Toranomon Hospital between January 2002 and August 2004. TMA was diagnosed in seven patients based on intestinal biopsy ( n = 6) or autopsy results ( n 1). While these patients showed some clinical symptoms such as diarrhea and/or abdominal pain, mental status alterations or neurological disorders were not observed in any of them. Laboratory results were mostly normal at the onset of TMA; > 2% fragmented erythrocytes ( n 1), < 10mg/dl haptoglobin ( n 1), and > 200 IU/dl lactic dehydrogenase (LD) ( n 4). On endoscopic examination, TMA lesions, consisting of ulcers, erosions, and diffuse exfoliation, were distributed spottily from terminal ileum to rectum. Intestinal graft-versus-host disease (GVHD) and cytomegalovirus (CMV) colitis were confirmed in five and four patients, respectively. With therapeutic measures including supportive care ( n 4), fresh frozen plasma ( n 1), and a reduction of immunosuppressive agents ( n 1), TMA improved in four patients. The present study demonstrates that intestinal TMA is a significant complication after RI-CBT. Since conventional diagnostic criteria can overlook TMA, its diagnosis requires careful examinationof the gastrointestinal tract using endoscopy with biopsy.