Summer-type hypersensitivity pneumonitis. T-cell receptor V gene usage in BALF T-cells from 3 cases in one family

Hypersensitivity pneumonitis (HP) is a granulomatous lung disease characterized by a T lymphocyte bronchiolalveolitis and in several recent studies the preferential use of V beta regions of T-cell receptor (TCR) has been demonstrated. In Japan, summer-type HP, caused by Trichosporon cutaneum, is the most prevalent type of HP, and it is known by the familial occurrence. To clarify whether TCR expression could be restricted on lung T-cell and associate with the HLA type in an organic antigen-driven hyperimmune status, we examined three cases of summer-type HP in one Japanese family.

TCR expression on bronchoalveolar lavage (BAL) fluid T-cells was analyzed with 13 TCR V gene specific monoclonal antibodies. In addition, HLA types were analyzed using the microlymphocyte toxicity method.

The changes in TCR expression were most frequently found in the BAL fluid CD8+ subset, but we found no preferential TCR V gene usage common to the three cases or correlation between the HLA type and the V gene usage. In two of the three cases who underwent a second lavage three months after the first one, some of the TCR expansions were preserved.

Preferential usage of several TCR V genes was observed in three cases with summer-type HP in one family, but we could find neither a common T cell expansion nor any correlation between the HLA type and the TCR V gene usage.