Evaluation of transbronchial lung biopsy specimens in the diagnosis of bronchiolitis obliterans after lung transplantation.

We investigated the utility of transbronchial lung biopsy in allograft evaluation, particularly with reference to rejection-mediated bronchiolitis obliterans in 105 transplant recipients surviving 3 months or more (29 single lung, 76 double lung). A sensitivity and specificity of one transbronchial biopsy procedure with an average procurement of 7.6 tissue fragments was 17.1% and 94.5%, respectively, according to results obtained from biopsies carried out after 2 months transplantation in 29 patients with confirmed rejection-mediated bronchiolitis obliterans and 61 patients known not to have the disease. The predictive value of a positive procedure for the presence of disease was 65.5% and that of a negative procedure for the absence of disease was 65.2%. Similarly, the sensitivity and specificity for the finding of bronchiolar mural fibrosis were 18.5% and 85.3%, respectively; and, for lymphocytic bronchiolitis, the values were 1.9% and 100%, respectively. We conclude that, although the sensitivity of transbronchial biopsy and the predictive value of a procedure which shows microscopic bronchiolitis obliterans are low, attempts should be made to support a clinical diagnosis of bronchiolitis obliterans through biopsy, given the problems inherent in achieving an early and certain diagnosis according to clinical criteria alone.