Antigen presentation in human autoimmune thyroid disease.

Monocyte/macrophage function in patients with autoimmune thyroiditis was investigated by their presentation of two distinct antigens; sheep red blood cells (SRBC) and human thyroglobulin (hTg) using in vitro systems designed for antibody induction. Purified peripheral blood monocyte/macrophages were primed by prefeeding with antigen for 60 min at 37 degrees C, washed, and co-cultured with autologous lymphocytes under a variety of incubation conditions. The most successful system employed 5% monocyte/macrophages with autologous T-B cells in the presence of the mitogen Staphylococcus aureus and B-cell differentiating factors. Under such conditions the anti-SRBC plaque-forming cell (PFC) response was amplified equally (approximately 10-fold) by SRBC-fed monocyte/macrophages in normal controls and patients with autoimmune thyroiditis rendered euthyroid with thyroxine replacement. hTg-fed monocyte/macrophages induced a 4-fold increase in anti-hTg PFC in selected patients with autoimmune thyroiditis examined under similar conditions (mean 36 +/- 3 PFC per 10(6) T-B cells). These data indicated that antigen processing by monocyte/macrophages was normal in patients with autoimmune thyroid disease.