Lung Function and Long-Term Complications after Allogeneic Hematopoietic Cell Transplant

It is unknown if diminished pulmonary function early after allogeneic hematopoietic transplant is associated with poor long-term outcomes. The objective of this study was to determine if posttransplant lung function is associated with 5-year nonrelapse mortality (NRM) and the development of chronic graft-versus-host disease (cGVHD). Retrospective analysis was done for 2158 patients who had routine pulmonary function testing 60-120 days after transplant between 1992 and 2004. Cox regression was used to assess the hazard ratio for 5-year NRM. A second analysis assessed the hazard ratio for the development of cGVHD. Lung function score was the primary exposure, and was calculated according to forced expiratory volume in 1 second (FEV1) and carbon monoxide diffusion capapcity (DLCO). Individual pulmonary function parameters were secondary exposures. The primary outcomes were 5-year NRM and the development of cGVHD. Most patients had normal lung function following transplant. A higher lung function score, signifying greater impairment, was associated with an increased risk of mortality (category 1 hazard ratio [HR] 1.47 [1.17-1.85]; category 2 HR 3.38 [2.53-4.53]; category 3 HR 7.80 [4.15-14.68]). A similar association was observed for all individual pulmonary function parameters. Low FEV1 was associated with the subsequent development of cGVHD (FEV1 70%-79% HR 1.26 [1.01-1.57]; 60%-69% HR 1.48 [1.10-2.01]; <60% HR 2.02 [1.34-3.05]). Models using either lung function score or individual pulmonary function parameters performed about equally well as judged by the C-statistic. Impaired lung function at day 80 posttransplant was associated with a higher risk of NRM. A low FEV1 following transplant was associated with developing cGVHD within 1 year.