Pulmonary function in long-term survivors of pediatric hematopoietic cell transplantation

Background. The purpose of this study was to determine the prevalence of pulmonary dysfunction in pediatric hematopoietic cell transplant (HCT) survivors and to identify associated risk factors. Procedure. In a cross-sectional study, patients surviving at least 5 years after pediatric HCT were requested to undergo pulmonary function testing (PFT). Risk factors for restrictive lung disease (RLD) and obstructive lung disease (OLD) were analyzed using multivariate analysis. Results. Among 472 patients contacted, 260 (55%) participated and 215 were selected for analysis. These patients were transplanted at a median age of 8.3 (0.3-18.0) years; 175 for hematologic malignancies and 40 for non-malignant diseases. The preparative regimens for 133 patients included fractionated TBI (FTBI), 29 single-fraction TBI (SFTBI), and 53 non-TBI regimens. PFT was performed at a median of 10 (5.0-27.5) years after HCT. Forty percent of patients had either RLD or OLD (28% RLD, 9% OLD, 3% mixed RLD/OLD) and at least 15% had an isolated low-DLCO. Moderate-to-severe impairment was present in 45% of patients with RLD or OLD. In multivariate analysis, risk factors associated with RLD included transplant regimen, transplant diagnosis, scleroderma/ contracture, and donor relation. Patients treated with SFTBI had the highest risk of RLD. Risk factors for OLD included chronic graft-versus-host disease, transplant regimen, and time after HCT. Patients surviving 20 or more years after HCT had the highest risk of OLD. Conclusions. Fifty-five percent of long-term pediatric HCT survivors had pulmonary dysfunction. These findings stress the need for longterm follow-up to detect pulmonary dysfunction.