1. ¹Department of Hematology, Toranomon Hospital, Tokyo, Japan
2. ²Hematopoietic Stem Cell Transplantation Unit, The National Cancer Center Hospital, Tokyo, Japan
3. ³Department of Pathology, Toranomon Hospital, Tokyo, Japan
4. ⁴Endoscopy Division, The National Cancer Center Hospital, Tokyo, Japan
5. ⁵Department of Cell Therapy and Transplantation Medicine, The University of Tokyo Hospital, Tokyo, Japan

Correspondence: Dr M Kami, Hematopoietic Stem Cell Transplantation Unit, National Cancer Center Hospital, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045, Japan. E-mail: mkami@ncc.go.jp

Received 18 April 2005; Accepted 2 June 2005; Published online 18 July 2005.

Abstract

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), <10 mg/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 examination of the gastrointestinal tract using endoscopy with biopsy.