Characterization and clinical relevance of circulating CD4+CD28- T cells in Graves' disease.

Abstract During autoimmune disease the fraction of CD4 + CD28 − T cells in the peripheral blood of has been found to be elevated. In the present study, peripheral blood was collected from 61 patients with Graves’ disease (GD) and 30 healthy control participants. Serum concentrations of thyroid-stimulating hormone (TSH), free triiodothyronine (FT3), free thyroxine (FT4) and thyrotropin receptor autoantibody (TRAb) were measured and peripheral blood mononuclear cell (PBMC) surface expression of CD4 and CD28 molecules was detected by flow cytometry. CD4 + CD28 − cells were sorted from six patients undergoing subtotal thyroidectomy and cultured ex vivo . The influence of TSH pretreated thyroid follicular cells on CD4 + CD28 − cell proliferation was evaluated using the agonist CD40 mAb 5C11, the blocking CD40L mAb 4F1 or B7-1 mAb 4E5 in 3 H-TdR assays. Our data showed that the fraction of CD4 + CD28 − T cells was higher in GD patients than healthy donors (10.21% ± 8.56% vs. 2.33% ± 1.94%; P vs. 15.21 ± 8.96%; P + CD28 − cells was detected in patients with degree II or III goiter than those with degree I goiter (11.53 ± 9.18% vs. 6.11 ± 3.97%; P vs. 6.11 ± 3.97%; P + CD28 − T cells correlated positively with serum levels of FT3 ( r  = 0.354, P r  = 0.304, P Ex vivo , 5C11 enhanced proliferation of CD4 + CD28 + cells ( P + CD28 − cells. 4F1 inhibited the proliferation of both CD4 + CD28 + ( P + CD28 − ( P + CD28 + cells ( P + CD28 − cells in GD patients correlates with disease severity and maybe plays an important role in the pathogenesis of GD.