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Objective: Although Graves' disease is considered an autoantibody-mediated, T-helper 2 (Th2)-dominant disease, Th1-dominance may prevail in its initial phase. We longitudinally investigated Th1/Th2 balance in untreated hyperthyroid patients with Graves' disease after treatment of methimazole (MMI), an antithyroid drug. Design: University clinic outpatients were studied prospectively. Patients: Subjects included 23 untreated hyperthyroid patients with Graves' disease and 17 agematched control subjects. Methods: Before and after treatment, we measured Th1-and Th2-associated chemokine receptors (CXCR)3 and CCR4, on peripheral blood lymphocytes using flow cytometry, as well as plasma concentrations of their ligands, interferon-inducible protein (IP)-10 and thymus and activationregulated chemokine (TARC). Results: The percentage of CXCR3-expressing cells among CD4C T lymphocytes and plasma IP-10 was significantly higher in hyperthyroid Graves' disease patients than in controls. At 12 and 24 weeks after initiation of MMI, percentage of CXCR3-expressing CD4 C T lymphocytes had decreased significantly, while the percentage of CCR4-expressing CD4 C T lymphocytes had increased significantly at 24 weeks. The CXCR3/CCR4 ratio had decreased significantly at 24 weeks. Plasma concentrations of IP-10 had decreased significantly at 12 and 24 weeks. Plasma concentrations of TARC also had decreased significantly at 24 weeks. Conclusions: In hyperthyroid patients with Graves' disease in the active phase, Th1 cells rather than Th2 cells predominated among peripheral blood lymphocytes. After initiation of MMI, an ongoing transition from Th1 to Th2 dominance occurred. 156 623-630 European Journal of Endocrinology

We investigated the effects of sitagliptin, a dipeptidyl peptidase (DPP)-4 inhibitor, on the number of circulating CD34(+)CXCR4(+)cells, a candidate for endothelial progenitor cells (EPCs), plasma levels of stromal cell-derived factor (SDF)-1α, a ligand for CXCR4 receptor and a substrate for DPP-4, and plasma levels of interferon-inducible protein (IP)-10, for a substrate for DPP-4, in patients with type 2 diabetes. We studied 30 consecutive patients with type 2 diabetes who had poor glycemic control despite treatment with metformin and/or sulfonylurea. Thirty diabetic patients were randomized in a 2:1 ratio into a sitagliptin (50 mg/day) treatment group or an active placebo group (glimepiride 1 mg/day) for 12 weeks. Both groups showed similar improvements in glycemic control. The number of circulating CD34(+)CXCR4(+) cells was increased from 30.5 (20.0, 47.0)/10(6) cells at baseline to 55.5 (31.5, 80.5)/10(6) cells at 12 weeks of treatment with 50 mg/day sitagliptin (P = 0.0014), while showing no significant changes in patients treated with glimepiride. Plasma levels of SDF-1α and IP-10, both physiological substrates of endogenous DPP-4 and chemokines, were significantly decreased at 12 weeks of sitagliptin treatment. In conclusion, treatment with sitagliptin increased the number of circulating CD34(+)CXCR4(+) cells by approximately 2-fold in patients with type 2 diabetes.

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