IN-VITRO EFFECTS OF CYTOKINES AND HUMAN THYROGLOBULIN ON THE INDUCTION OF ANTIBODY-SECRETING CELLS IN PATIENTS WITH AUTOIMMUNE THYROID-DISEASE

We have investigated the in vitro effects of interleukin-1-beta (IL-1- beta), interleukin-2 (IL-2), tumor necrosis factor-alpha (TNF-alpha), and interferon-gamma (IFN-gamma) on the induction of anti-thyroperoxid ase (anti-TPO), anti-thyroglobulin (anti-Tg), and IgG-secreting cells (SC) by cultures of pokeweed mitogen (PWM)-stimulated peripheral blood mononuclear cells (PBMC) obtained from patients with Hashimoto's thyr oiditis (HT), Graves' disease (GD), and controls (C). The effect of hu man thyroglobulin (Tg) together with cytokines was also studied. No di fferences in the numbers of PWM-induced IgG-SC were found. However, gr eater numbers of PWM-induced anti-TPO-SC were observed in the HT prepa rations compared to C, either with or without the addition of Tg (p < 0.05). Inhibition of numbers of IgG-SC with certain cytokines in all 3 groups of preparations was observed (0.01 <p < 0.05). Decreased numbe rs of anti-TPO-SC were noted in HT preparations after exposing cells t o IL-2 and TNF-alpha. Induction of anti-TPO-SC after addition of Tg pl us cytokines was significantly lower in HT than in the other 2 groups. In contrast, induction of anti-TPO-SC in C was markedly increased by all cytokines, which was enhanced by Tg. These data suggest that cytok ines play a role in auto-anti-body regulation in auto-immune thyroid d isease (AITD).