Plaque-forming cells in autoimmune thyroid disease

Antigen Presentation in Human Autoimmune Thyroid Disease

“…Such a conclusion was in agreement with an earlier macrophage study which ob served normal enhancement of T-cell colony formation in patients with autoimmune thy roiditis [14], Despite the ease with which anti-SRBC PFC were induced it was not possible to induce anti-hTg PFC in normal individuals. This was the third series of experiments we have reported concerning normal individuals in which we have failed to observe thyroid autoantibody secretion [2,4] and was in keeping with other workers [5,[15][16][17], Re cent reports of anti-hTg PFC in normal PMC cultures require careful evaluation and con firmation [18]. In particular, the recognition and specificity of plaques may lead to errone ous interpretations and the presence of anti-SRBC PFC in anti-hTg PFC assays, and po tential contamination of hTg preparations must be carefully excluded [4], It was also difficult to detect induction of hTg-Ab in patients with autoimmune thy roiditis and high serum titers of hTg-Ab.…”

“…This was the third series of experiments we have reported concerning normal individuals in which we have failed to observe thyroid autoantibody secretion [2,4] and was in keeping with other workers [5,[15][16][17], Re cent reports of anti-hTg PFC in normal PMC cultures require careful evaluation and con firmation [18]. In particular, the recognition and specificity of plaques may lead to errone ous interpretations and the presence of anti-SRBC PFC in anti-hTg PFC assays, and po tential contamination of hTg preparations must be carefully excluded [4], It was also difficult to detect induction of hTg-Ab in patients with autoimmune thy roiditis and high serum titers of hTg-Ab. Such results were reminiscent of earlier expe riences with the influence of soluble hTg anti gen on peripheral immune cells [2,5], How ever, one report has stated that patients with autoimmune thyroiditis consistently exhib ited hTg-antigen induction of hTg-Ab secre tion using peripheral blood lymphocytes [15] and that such induction could be mimicked by hTg-fed autologous and non autologous monocyte/macrophages [16].…”

“…Pa.) and guinea pig complement used in all assays for final plaque development (1/50 for 60 min). Specificity of these assays has been previously documented [3,4], Values were expressed as PFC per I06 cells initially cultured ± SEM and normalized where indicated.…”

“…Plaque-forming cell assays for total immunoglobu lin, hTg-Ab and SRBC antibody secreting cells were performed as described in detail in our earlier publica tions [1][2][3][4]. In the direct anti-SRBC assay, washed SRBC were used as indicator cells.…”

“…The system employed a mild proliferative stimulus with the mito gen Staphylococcus aureus combined with monocyte/macrophage-derived B-cell differ entiating factors and utilized specific plaque forming cell (PFC) assays for human thyro globulin autoantibody (hTg-Ab) and imrnunoglobin secretion [1][2][3][4], Using this approach we have shown that patients with autoim mune thyroiditis had peripheral blood mono nuclear cells able to exhibit thyroid antigeninduced. antigen-specific, autoantibody re sponses when hTg-Ab production was used as the end point [2], However, only a minor ity of patients exhibited such responses and this difficulty in demonstrating antigen-spe cific thyroid autoantibody induction may have been secondary to sequestration of cir culating memory-B cells [5.…”