[Post-transfusion GVHD].

The Japanese Red Cross Society has appointed representatives to Blood Centers nationwide to collect information on blood transfusion-associated adverse reactions, and data on 310 suspected cases of post-transfusion GVHD were collected during the 8-year period from 1993 to 2000. A diagnosis of post- transfusion GVHD was made in 61 cases based on the demonstrated presence of donor lymphocytes in the patients' peripheral blood using a microsatellite analysis technique developed by the Japanese Red Cross Society. Case distribution was analyzed according to patient background characteristics. In a majority of the cases examined, transfusion was made from a homozygous donor of a HLA haplotype to a heterozygous patient of the specific HLA haplotype. The analysis of data also revealed that patients aged 70 and those undergoing transfusion for the first time were more liable to develop post-transfusion GVHD. Cells cloned from patient peripheral blood lymphocytes were assessed for their immunological char- acteristics to delineate subsets involved in GVHD. Analysis of these clones has led to the discovery of a drug (Futhan ® ; Tor ii Pharmaceutical) which suppresses their cytotoxic activity of these clones. The drug has proven to be effective both in vitro and in vivo.