The serum concentrations of thyroid hormone, anti-thyroglobulin (Tg) and anti-thyroperoxidase (TPO) antibodies were measured by chemiluminescent immunoassay (Maglumi 2000 Plus) according to the manufacturer’s protocol. Twenty age- and sex-matched healthy subjects were included as controls. Peripheral blood selleck chemicals samples were obtained from all patients and healthy controls. Thyroid

glands were obtained from six HT patients who were undergoing thyroidectomy. All the patients were positive for Tg-antibody and TPO-antibody and had normal hormone levels, except for one patient (FT4: 7·92 pmol/l). Two of the patients were bilateral goitre; others were unilateral. Lymphocytic infiltration was detected in the goitres. Thyroid tissue from the patient with simple goitre was used as control. Ethical approval was obtained from the Affiliated People’s Hospital of Jiangsu University, and informed consent was obtained from all individuals.

Levels of plasma leptin and CD4+ T cells-derived leptin were measured using a human leptin ELISA immunoassay GDC-0449 concentration (R&D Systems, Minneapolis, MN, USA), following the manufacturer’s protocol. Human peripheral blood mononuclear cells (PBMCs) were isolated by standard density-gradient centrifugation over Ficoll-Hypaque solution. Plasma samples were collected through centrifugation and stored at –80°C for measurement. Human CD4+ T cells were purified from PBMCs Rebamipide by magnetic beads using a CD4+ T Cell Isolation Kit (Miltenyi Biotec GmbH, Bergisch Gladbach, Germany), with purity routinely higher than 95%. CD4+ T cells were cultured in RPMI-1640 medium supplemented with 10% fetal bovine serum, 100 U/ml penicillin

and 100 μg/ml streptomycin at 37°C in a humidified atmosphere of 5% CO2. For leptin detection, CD4+ T cells were cultured with anti-human CD3 monoclonal antibody (mAb) (10 μg/ml) and anti-human CD28 mAb (2 μg/ml) for 72 h. Supernatants were then used to detect the levels of leptin by ELISA. For in-vitro blocking experiments, 10 μg/ml human leptin-neutralizing mAb (R&D Systems) was administered in CD4+ T cell culture in the presence of soluble anti-human CD3 mAb (10 μg/ml) and anti-human CD28 mAb (2 μg/ml); the irrelevant isotype-matched antibody was used as control. Thyroid specimens were minced and then digested with collagenase II (Sigma-Aldrich, St Louis, MO, USA) for 1–2 h at 37°C and then isolated by density-gradient centrifugation. Finally, thyroid mononuclear cells (TMCs) were obtained. The viability of cells was found to be higher than 95%.