Activated T Cells in Bronchoalveolar Lavage Fluid from Patients with Respiratory Diseases

Abstract

This study was performed to investigate the presence of Ia-like antigen as a marker of activated T cells in bronchoalveolar lavage fluid (BALF) from patients with sarcoidosis (SAR), idiopathic interstitial pneumonia (IIP), pneumoconiosis (PC), hypersensitivity pneumonitis (HP) and healthy volunteers (HV). We also examined the peripheral blood of the above-mentioned groups. In the four disease groups, the ratio of activated T cells to pan T cells (ATR) in BALF and peripheral blood was significantly higher in comparison with HV. ATR in BALF was markedly higher than that in peripheral blood in the four mentioned above disease groups and in HV. We compared the relationship between the activated T cell number and 2T cell subset numbers, OKT4^+T cell numbers and OKT8^+T cell numbers. In SAR, IIP and PC, the activated T cell numbers and the OKT4^+T cell numbers were significantly correlated (r=0.91, 0.94, 0.91 ; p<0.01 : respectively). On the other hand, the coefficient of correlation between activated T cell numbers and OKT8^+T cell numbers was 0.68(p<0.05), 0.95(p<0.01) and 0.57(p>0.05), respectively. There was no significant relationship between activated T cell numbers and OKT4^+T cell numbers, nor between activated T cell numbers and OKT8^+T cell numbers in HV. These results suggest that BALF-activated T cells bearing OKT4^+ have an important role in the pathogenesis of SAR and PC. However in the case of IIP, BALF-activated T cells bearing OKT8^+ were responsible for the pathogenesis as much as activated T cells bearing OKT4^+.