POSTTRANSFUSION GRAFT-VERSUS-HOST DISEASE IN JAPANESE NEWBORNS

Background: Posttransfusion graft-versus-host disease (PT-GVHD) is und erdiagnosed and underreported. Risk factors predisposing to PT-GVHD in newborn recipients, the clinical manifestations of the disease in new borns, and its mechanism are not well characterized. Study Design and Methods: A literature review identified 27 cases of PT-GVHD in newborn s in Japan. Detailed information on volume of blood transfused, donor( s), and clinical course was analyzed. Infants with known immunodeficie ncy were excluded. Results: Of 27 newborns, 20 were premature and 7 we re full-term. Thirteen premature neonates were transfused frequently b ecause of anemia; in 10 cases, exchange transfusion was performed. Fre sh blood (less than or equal to 72 hours after donation) and blood fro m family member(s) were transfused to 25 and 22 neonates, respectively . The clinical manifestations of PT-GVHD developed later after transfu sion than is reported in adults; the median intervals were: fever, 28 days; erythematous rash, 30 days; leukopenia, 43 days; and death, 51 d ays. Thymic damage was a striking feature among newborns. Two thirds o f the cases of PT-GVHD were associated with overwhelming infections, a nd all patients died in spite of various treatments. Conclusion: These data suggest that cellular blood components, especially those from fa mily members, should ge irradiated before transfusion to premature and fullterm neonates. Extrathymic and/or thymic semitolerance for alloge neic-donor cytotoxic T-lymphocytes may explain the longer period of la tency before the onset of clinical manifestations and the longer cours e of disease before death in newborns than are noted in adults, as wel l as the fewer than expected reported cases of PT-GVHD in neonates.