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

Abstract

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. Retrospective database analysis of pulmonary function tests of patients undergoing first myeloablative BMT at two large children's hospitals. 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. 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.