92: Degree of Concordance between CARGO and Biomarkers in Transplantation

Abstract

provide invaluable information to alert clinicians as to the development of OB. Methods and Materials: A systematic examination of TBB samples from 8 stable lung transplant recipients and 8 with a clinical diagnosis of bronchiolitis obliterans syndrome (BOS) was conducted by an experienced transplant pathologist blinded to the clinical status. All samples contained at least two specimens of lung tissue containing membranous bronchioles (median 3, range 2-6). In each case the degree of epithelial denudation, subepithelial collagen deposition and mucosal inflammation was assessed. Based on these observations a global consideration was made on each case classified as to whether OB was likely, possible or unlikely. Results: In biopsies from stable recipients 6 out of 8 (75%) were classified as unlikely to have OB and 2 out of 8 as possible. None of the stable recipients were considered likely to have OB based on this histological assessment. In 7 of the 8 patients with BOS (88%) were classified as possible (3) or likely (4). In only 1 case was the diagnosis of OB felt unlikely on the biopsy from a patient with clinical BOS. Using a 2 by 2 contingency table, those with clinical BOS were significantly more likely to have features identifiable on TBB suggesting OB than stable patients. Fisher Exact Test p 0.02. Conclusions: Evaluation of subtle histological features suggestive of OB is possible on TBB. Patients with clinical BOS are significantly more likely to have these features compared with stable patients. TBB may help contribute to the diagnosis and alert the clinician to the development of OB.