The role of certain immunologic parameters in silicosis

The paper presents some possibilities of estimating the immunologic aggression in silicosis in a group of 68 patients divided into three subgroups according to the evolutive stage of disease. The results were compared with the data obtained in a control group of 35 clinically healthy subjects not subjected to respiratory noxae. Parameters such as the immunogram (IgG, IgA IgM, IgD), the C3 complement, the circulating immune complexes (CIC) and the C reactive protein (CRP) were investigated using classical immunochemical methods. It was observed that the immunoglobulin titer presented a polyclonal increase. The mean values of C3 complement decreased in stages I and II of disease. The CIC level presented high mean values unrelated to the stage of the disease. The incidence of CRP was found high in stage III. It was demonstrated that there is no significant correlation between the humoral immunologic abnormalities and the radiologic changes or the depression of the pulmonary functional test. These changes suggest that the humoral immunologic abnormalities are not directly responsible for the lung changes in silicosis and cannot be used as a predictive indicator of the severity of the disease or of its progress. The data obtained showed a hyperreactivity of the humoral mediated immunity over the whole course of the disease thus supporting the assumption of an immunopathogenic mechanism in this disease.