The anatomic distribution of acute cellular rejection in the allograft lung

Background. Transbronchial lung biopsy (TBLB) is used for routine monitoring and diagnosing of acute cellular rejection (ACR) in the lung allograft, and yet the optimal anatomic site for lung biopsy has not been investigated. We examined our clinical data to clarify the distribution of ACR in the lung allograft monitored by TBLB. Methods. A retrospective case-series study was done reviewing the pathology files and slides of TBLB performed on lung allograft recipients. In 73 patients, transbronchial biopsies were taken from more than one lobe. Results. Identical grades of ACR were seen in 33 of 73 (45%) patients, and a single-grade difference in ACR was noted 34 of 73 (47%) patients. Six cases demonstrated two or more grade differences on biopsies taken from two separate lobes. Among cases with different grades of ACR, the “upper” lobes had a higher grade in 35% (14/40) and the “lower” lobes had a higher grade in 65% (26/40). Conclusions. If limitations on the site for transbronchial biopsy exist, biopsies of the lower lobes appear more informative.