Interstitial pneumonitis following allogeneic bone marrow transplantation in the treatment of leukemia based on BMT survey in Japan

Data from 208 patients with leukemia who were treated with allogeneic bone marrow transplantation between 1975 and 1985 were reported to the Japanese Bone Marrow Transplant Registry and were available for this analysis. These patients were classified into 82 of acute lymphocytic leukemia, 91 of acute non-lymphocytic leukemia, and 35 of chronic myelocytic leukemia. The incidence of interstitial pneumonitis (IP) was 39% (81/208) and fatality rate was 60% (49/81). Cytomegalovirus was the most frequent causative organism (54%). Using Cox's proportional hazard regression model, age of recipient (P = 0.0068), status of disease (P = 0.0191), and number of platelet transfusion (P = 0.0425) were found to be significant risk factors associated with IP. Probabilities of developing IP at three years were 65% and 42% in single dose and fractionated total body irradiation (TBI), respectively. In single dose TBI group, dose-rate affected the incidence of IP. On the contrary, in fractionated TBI group, number of fractions as well as dose-rate had no impact on the incidence of IP.