[Successful treatment with prednisolone for air-leak syndrome following interstitial pneumonia after allogeneic hematopoietic stem cell transplantation].

A 13-year-old boy with T lymphoblastic leukemia underwent allogeneic bone marrow transplantation from an HLA-matched sibling in the second remission phase. After the dose of cyclosporine (CyA) was reduced, dyspnea appeared on Day 117. CT revealed diffuse interstitial shadows on the bilateral lungs. The results of broncho-alveolar lavage suggested Pneumocystis jirovecii pneumonia. The dose of trimethoprim-sulfamethoxazole was increased, and steroid therapy was started. The symptoms transiently subsided, but exacerbated with a reduction in the steroid dose. On Day 139, mediastinal and subcutaneous emphysema appeared. We considered that non-infectious interstitial pneumonia was primarily involved in the pathogenesis for the following reasons: the boy was negative for β-D-glucan early after onset, and there was a correlation between the steroid-dose reduction and condition. The steroid dose was again increased to 80 mg and the symptoms promptly subsided. When late-onset non-infectious pulmonary complications after hematopoietic stem cell transplantation lead to air-leak syndrome, the mortality rate is very high. However, survival may be achieved by intensifying immunosuppressive therapy in the early stage.