¹Department of Hematology, Imamura Bun-in Hospital, Kagoshima, Japan

Correspondence: Dr K Obama, Department of Hematology, Imamura Bun-in Hospital, 11-23 Kamoike-shinmachi, Kagoshima 890-0064, Japan. E-mail: patagonta@yahoo.co.jp

Received 26 October 2003; Accepted 17 May 2004; Published online 13 September 2004.

Abstract

With the recent progress in reduced-intensity conditioning stem cell transplantation (RIST) and taking into consideration the concept of feto-maternal immunological tolerance, we carried out non-T-cell depleted HLA haploidentical RIST from noninherited maternal antigen (NIMA) complementary siblings or offspring donors for four older patients: a patient with myeloplastic syndrome (MDS) and three patients with adult T-cell leukemia (ATL) in partial remission or with progressive disease. All patients showed early, durable engraftment, and no serious toxicities were observed apart from grade III mucositis in one case. Grade II acute GVHD occurred in two cases, which was well-controlled. In one ATL patient whose donor did not have NIMA microchimerism, tacrolimus could not be continued after engraftment due to renal dysfunction, and grade III acute GVHD (gut: stage 4) occurred on day 35. A patient with MDS was free from disease (requiring no transfusions and with a normal bone marrow) for 15 months. Two cases of ATL relapsed. Feto-maternal tolerance may lead to new RIST strategies in the haploidentical reduced-intensity situation, but further evaluation is required.