Bronchiolitis obliterans syndrome is not specific for bronchiolitis obliterans in pediatric lung transplant

Background Bronchiolitis obliterans (BO) is the leading cause of mortality beyond the first year after pediatric lung transplant, but the performance of an open lung biopsy is often required for diagnosis. Bronchiolitis obliterans syndrome (BOS) is a clinical diagnosis based on spirometric data that is the accepted standard for staging chronic allograft dysfunction. Methods We determined the sensitivity, specificity, and positive and negative predictive values of BOS for predicting BO in children. A chart review was conducted on 139 open lung biopsies and 43 lung explants performed at our center from 1990 through June 2010 in pediatric recipients of lung transplants. Results were excluded from analysis if insufficient data existed to calculate a stable BOS stage before biopsy/explant. Results The criteria for inclusion in the study were met by 67 open lung biopsies and 31 lung explants. The sensitivity, specificity, positive predictive value, and negative predictive value of BOS for predicting BO were 91.0%, 25.8%, 72.6%, and 57.1%. Conclusions We found that early declines in lung function are sensitive, but not specific, for BO. The low specificity of BOS for identifying BO illustrates the challenge facing clinicians in determining the etiology of pulmonary decline after lung transplant.