Pre‐transplant lung function is predictive of survival following pediatric bone marrow transplantation

BACKGROUND: Pulmonary toxicity is well described in recipients of bone marrow transplants (BMT), and accounts for a sizeable proportion of post-transplant mortality. The majority of the data on post-transplant pulmonary function is from adults, although several small pediatric case series have been described. In adults, pre-transplant lung function has been predictive of post-transplant respiratory failure and mortality. This use of pulmonary function testing, that is, for pre-transplant risk counseling, is novel but has never been applied to pediatric patients. We hypothesized that in children, as in adults, pre-transplant pulmonary function would also be predictive of outcome post-transplantation morbidity. PROCEDURE: Retrospective database analysis of pulmonary function tests of patients undergoing first myeloablative BMT at two large children's hospitals. RESULTS: Two hundred seventy-three subjects had at least one pre-transplant PFT, and 317 subjects had at least one post-transplant PFT available for analysis. While the majority of patients had normal or mildly reduced pre-transplant flows and lung volume, 25% had moderately or severely reduced diffusion. All lung function parameters decreased post-transplant with a slow improvement over ensuing years. The Lung Function Score, a combined measurement of FEV(1) and DLCO, was highly associated with post-transplant survival. Hazard ratios for mortality (compared to the best LFS) ranged from 1.654 to 2.454. CONCLUSIONS: Lung function prior to bone marrow transplant, especially diffusing capacity, is frequently abnormal. Lung function frequently decreases shortly post-transplant and tends to improve over time, but frequently remains abnormal even years after transplant. Post-transplant survival is related to pre-transplant lung function.