Evaluation of cases with silicosis using the parameters related to Fas-mediated apoptosis

To establish a new clinical index for immunological abnormalities occurring in silicosis, several clinical parameters related to Fas-mediated apoptosi s; i.e., membrane Fas expression on peripheral blood lymphocytes (mFas), se rum soluble Fas levels (sFas), serum soluble Fas ligand levels (sFasL), and soluble/membrane Fas mRNA expression ratios (s/mFas ExR) in peripheral blo od mononuclear cells (PBMC) were investigated. Fifty-eight silicosis patien ts with no clinical symptoms of autoimmune diseases were the subjects of th is study. Factor analysis was performed using 12 clinical parameters includ ing four parameters related to Fas-mediated apoptosis. Two common factors w ere identified. Factor 1 which consisted of the following parameters; durat ion of exposure, symptomatic dyspnea, PO2, PCO2, and A-aDO(2), should be de signated as the respiratory factor for cases with silicosis. The parameters of factor 2 were serum IgG, sFas with high factor loading, titer of ANA, s FasL, and s/mFas ExR. These parameters of factor 2 are indicative of the im munological disorders occurring in silicosis cases. Some cases exhibited ab normalities in parameters of factor 2 but not factor 1. The factor analysis clearly demonstrated that the parameters related to Fas-mediated apoptosis should be the most beneficial for predicting the pre-clinical status of co mplicated autoimmune diseases in silicosis.