Immune intervention effects on the induction of experimental autoimmune thyroiditis

To explore immune intervention effects of the combined use of cycloporin A (CsA) and 1, 25-dihydroxyvitamin D3[1,25(OH)2D3] at low doses on experimental autoimmune thyroiditis (EAT), porcine thyroglobulin (pTG) was injected into a CBA mouse at the dose of 100 micrograms on day 0 and day 14 to establish the model of EAT. The immune prevention group from day 0 to day 28, and treatment group from day 10 to day 38 were daily administered CsA (10 mg/kg) intragastrically and/or 1,25(OH)2D3 (0.2 microgram/kg) i.p. After immunized by pTG, the mice were sacrificed on day 28 and day 38 to examine their thyroid gland pathologically, and to check the levels of serum porcine thyroglobulin antibodies (pTGAb), porcine thyromicrosomal antibodies (pTMAb). The incidences of EAT in the immune prevention group and treatment group, with administration of low dose of CsA and 1,25(OH)2D3, were decreased respectively by 44.44% and 37.50%. Those of severe disease in the two groups were decreased respectively by 71.43% and 60.32%. The levels of serum pTGAb and pTMAb in the immune prevention group were lower than those of the positive control group. It was concluded that combined use of CsA and 1,25(OH)2D3 at low doses could effectively prevent EAT with a synergic effect.