CYTOKINE GENE-EXPRESSION IN HUMAN LUNG-TRANSPLANT RECIPIENTS

The polymerase chain reaction was used to evaluate cytokine gene expre ssion in bronchoalveolar lavage (BAL) cells and peripheral blood leuko cytes in 31 human lung transplant recipients. All patients were mainta ined on a triple immunosuppression regimen consisting of CsA, AZA, and prednisone. Posttransplant survival ranged from 0.5 to 100.5 months ( mean = 16.3 months). Cytokines IL-1alpha, IL-2, IL-4, IL-5, IL-6, IL-7 , IL-8, TNF-beta, and IFN-gamma were studied. In BAL, transcripts for IL-1alpha, IL-7, IL-8, and TNF-beta were found in over 60% of samples and those for IL-5, M-6, and IFN-gamma in 40-50%, while IL-2 and IL-4 mRNA were rarely found (<20%). Considerable variation in the frequency of cytokine gene expression between BAL and peripheral blood was obse rved. When analyzed for the presence of acute pulmonary allograft reje ction (without infection), transcripts for IL-4 and IL-6 in BAL demons trated the greatest increase in frequency compared with nil rejection (P=0.07 and P=0.17, respectively). Pulmonary infection (without reject ion) was associated with a modest increase in the expression of genes for IL-1alpha and IFN-gamma (>10%). Transcripts for IL-4 were not foun d in association with pulmonary infection, suggesting that this cytoki ne may be useful as a discriminatory rejection marker.