[Interactions between serum antibodies of patients with autoimmune thyropathies and isolated cells of diffuse toxic...

Blood sera of 46 patients with diffuse toxic goiter (DTG) and of 48 ones with Hashimoto's thyroiditis (HT) were tested for antibodies--complement-mediated cytotoxicity carriers (ACMMC). ACMCC targets were isolated DTG cells and cells of euthyroid nodular goiter (ENG) perinodular tissue. Antimicrosomal antibodies were assayed in the sera by indirect immunofluorescence and antibodies to all thyrocyte surface antigens isolated from both tissue samples were determined by solid-phase enzyme immunoassay. When DTG cells were targets, DTG patients' sera detected ACMCC in 36% of cases and HT patients' sera in 73% of cases (p < 0.001). In ENG cells the sera of patients of both groups detected ACMCC equally frequently (in more than 70% of cases). Of the 27 DTG patients' sera tested with both tissues approximately a half detected ACMCC in only ENG tissue. There was no difference in HT patients' sera effects on ACMCC detection in both tissue samples. This has brought the authors to a conclusion about DTG cells deficiency for ACMCC mediating antigens. Moreover, DTG cells bound much less antibodies from sera of patients with autoimmune thyropathies, than ENG cells (p < 0.001), this confirming a deficiency of surface antigen on DTG cells. No correlation between the presence in the sera of antimicrosomal cells and of ACMCC was detected. A conclusion has been made about heterogeneity of antimicrosomal antibody population and about the presence of ACMCC in blood sera of patients with autoimmune thyropathies, these antibodies not belonging to antimicrosomal ones. ACMCC also may be heterogeneous and differ in DTG and HT patients.