The concern of a study by Crim et al. (A-19) was the potential role of flow cytometric analysis of bronchoalveolar lavage fluid (BALF) in diagnosing acute lung rejection. The investigators note that previous studies suggested an association of acute lung rejection with increases in CD8þ lymphocytes, and increased expression of human lymphocyte antigen (HLA)-DR antigen and interleukin-2 receptor (IL-2R). Subjects consisted of lung transplant (LT) recipients who had no histologic evidence of rejection or infection, normal human volunteers (NORM), healthy heart transplant (HT) recipient volunteers, and lung transplant recipients who were experiencing acute lung rejection (AR). Among the data collected were the following percentages of BALF CD8þ lymphocytes that also express IL-2R observed in the four groups of subjects.

Norm HT LT AR 0 0 1 6 12 2 0 0 60 1 5 5 89 0 4 0 16 7 0 6 0 24 2 2 0 5 56 3 0 18 3 14 0 4 2 22 10 0 8 2 10 3 1 8 8 00 0 80 7 31 2 41 5 40 1 18 0 0 4 Source: Data provided courtesy of Dr. Courtney Crim.