The Levels of Regulatory T Lymphocytes and B Cells in Patients with Graves' Disease after Thyroidectomy

Aim: To study the levels of regulatory T lymphocytes (Treg) and B-cells in peripheral blood in patients with Graves' disease in dynamics after thyroidectomy. Design: Single center, observational, prospective, cohort, open, controlled study. Materials and methods. The study included 96 patients with Graves' disease, mean age 42.86 ± 10.81 years. Clinical, hormonal and immunological examinations were performed against the background of persistent drug-induced euthyroidism, before surgery, and also 1, 3, and 6 months after thyroidectomy. The levels of Treg and B-cells in the blood was examined by flow cytometry using direct immunofluorescence and monoclonal antibodies. The level of antibodies to thyroid-stimulating hormone receptors (rTSH) was assessed by enzyme immunoassay. The control group consisted of 85 healthy women of the same age. Results. In patients with Graves' disease in the dynamics of the postoperative period, there was a consistent statistically significant decrease in the titer of antibodies to rTSH: from 14.69 (8.67–19.81) to 0.81 (0.59–0.93) IU/l. The absolute amount of Treg in their blood was reduced relative to the control values already in the preoperative period and decreased even more at 6 months after thyroidectomy. The proportion of CD19+CD5+- and CD19+CD5–-cells in the examined patients before surgery was significantly higher than in the control group. The content of CD19+CD5+ cells decreased as early as 1 month after thyroidectomy and remained at the level of control values. The сontent of CD19+CD27–-cells in patients with Graves' disease in the preoperative period was higher than in the control group, decreased to the control values 1 month after thyroidectomy and remained in this range until the end of the follow-up. The content of CD19+CD27+ cells in patients before thyroidectomy was lower compare to control, in the period of 1–3 months it corresponded to the control values, but decreased again on the 6th month after surgery. Conclusion. The reduction of Treg and B-memory cells in the peripheral blood in patients with Graves' disease six months after thyroidectomy remains of immunosuppressive regulatory mechanisms with an increase in the migration activity of immune cells for a long time. Keywords: Graves' disease, thyroidectomy, regulatory T lymphocytes, memory B cells, target therapy.