Reduced lung function in leukaemia patients undergoing bone marrow transplantation

20 patients with leukaemia in remission or early relapse received an allogeneic bone marrow graft. Patients were conditioned according to Seattle protocol with high dose cyclophosphamide and total body irradiation to a total dose of 8 Gray to the lungs delivered by a 6 MV linear accelerator at a dose rate of approximately 0.06 Gray/min. As prophylaxis against the graft versus host reaction, methotrexate and/or cyclosporin A were given. Lung function was studied prior to treatment and every 3 months thereafter. Before treatment a marked decrease was seen in the CO diffusion capacity when compared to the predicted value, while the flow volume relationships were within normal limits. The cause of this is unknown, but may be due to previous infections and the cytostatic treatment given. After bone marrow transplantation, a further irreversible decrease was seen in the CO diffusion capacity and vital capacity indicating an additive effect of the lung irradiation.