Considerations on the changes of certain immunologic cells in silicosis

Cell-mediated immunity was estimated in a group of 68 patients divided into three subgroups according to the evolutive stage of disease. It was demonstrated that in silicosis there is a disturbance of immunity. The detection of E rosettes and of activated rosettes was carried out according to the classical method. The mean percentage of total T lymphocytes was found lower in silicosis (62 +/- 2% statistically significant for p < 0.05), compared to the control group (66 +/- 4.6%). The study revealed a decrease of T helper lymphocytes, an increase of T suppressor/cytotoxic lymphocytes and a decrease of the T helper/T suppressor ratio (1.96 +/- 0.13) in silicosis as compared to the control group (2.83 +/- 0.31). The presence of these changes in silicotic patients suggested the participation of cell-mediated immunity in the pathogenesis of disease, the cell mediated immunity being directly responsible for the evolution of silicosis.