T-CELL RECEPTOR-V GENE-EXPRESSION IN HLA-TYPED JAPANESE PATIENTS WITHPULMONARY SARCOIDOSIS

The clinical features of sarcoidosis vary in different ethnic groups, suggesting that different genetic or environmental backgrounds influen ce the disease. In Scandinavian sarcoidosis patients, we have previous ly described a correlation between lung-accumulated CD4(+) T cells exp ressing the T-cell receptor (TCR) V-alpha 2.3 gene segment and a parti cular HLA type (DR3[17],DQ2). For purposes of comparison, we have in t his study investigated TCR V gene usage and gamma delta TCR expression in CD4(+) and CD8(+) T cells in bronchoalveolar lavage (BAL) fluid an d peripheral blood in an ethnically distinct and homogenous group of i ndividuals consisting of Japanese sarcoidosis patients and healthy con trols. We used a panel of 13 monoclonal antibodies (Mab) specific for different TCR V genes, which altogether stained approximately 50% of t he T cells, and triple staining techniques with flow cytometry. The pa tients and controls were also HLA-typed. Our results show a high degre e of expression of gamma delta TCR in peripheral blood T cells of clos e to half of the patients. Expansions of T-cell subsets were readily d etected in the CD8(+) T-cell population, while a more homogenous stain ing pattern was found in the CD4(+) T-cell population. These findings show the importance of ethnic origin and environment in discussions of TCR V gene usage.