ACCUMULATION OF MULTIPLE T-CELL CLONOTYPES IN LUNGS OF HEALTHY-INDIVIDUALS AND PATIENTS WITH PULMONARY SARCOIDOSIS

T cell accumulation and activation in lung may play a major role in th e pathogenesis of immunologic lung diseases such as sarcoidosis. Using the combination of RT-PCR and subsequent single-strand conformation p olymorphism analysis, we examined T cell clonality in lung and periphe ral blood of healthy individuals (n = 5) and patients with active pulm onary sarcoidosis (n = 7). RNA was extracted from PBLs and bronchoalve olar lavage fluid cells, and converted to cDNA. PCR was performed usin g a set of V beta-C beta primers (VP 1-20). Products were denatured an d electrophoresed in nondenaturing 5% polyacrylamide gel. The existenc e of a distinct T cell clonotype was detected as a band on a smear. In both groups T cells in PBLs showed a number of clones that expanded. A significantly greater number of clones was detected in BAL compared with PBL in both groups (normal: 25.3 +/- 7.2 in PBL vs 62.8 +/- 5.2 i n lung; sarcoid: 25.0 +/- 6.2 in PBL vs 90.0 +/- 6.6 in lung, mean val ue +/- SEM). In sarcoid lung greater numbers of clones were detected t han in lungs of healthy controls (p < 0.012). These clonal expansions were observed over all the 20 V beta families examined, and were not r estricted to certain V beta families. These results suggest that there are clonal expansions even in normal lung, and that in sarcoidosis, a pparently, additional T cell clones using multiple V beta segments mig ht be activated and accumulated at the site of the disease.