Toll like receptor 4 (TLR4) expression on peripheral blood mononuclear cells (PBMCs) among patients with Graves disease

Abstract

Graves disease (GD) is a multifactorial disease due to multiple environmental and genetic factors as well as immune malfunction. Human Toll-like receptors (TLRs) play a key role in activating innate and adaptive immune cells. Their role in modulating immunity also interferes with the mechanisms that maintain tolerance in the host. Thus, expression or activation of TLRs can contribute to the loss of tolerance by a lot of mechanisms. In order to confirm the importance of TLR4 in the pathogenesis of GD, this study intended to measure TLR4 expression on peripheral blood mononuclear cells in GD patients before and after control of disease with Carbimazole as compared to a group of normal controls. We conducted a case-control study on 36 patients with newly diagnosed Graves disease and 36 individuals as the control group. Patients were recruited from the endocrinology outpatient clinic, Ain-Shams University Hospitals and were followed up till achieving the euthyroid state (for a minimum period of 6 months). In GD patients at baseline, the mean monocyte percentage was 4.46%, and the mean TLR4 on monocytes 90.91%. After achieving euthyroid state, the mean monocyte was 6.16%, and the mean TLR4 on monocytes 72.30%. In the control group, the mean monocyte was 3.88%, and the mean TLR4 on monocytes 66.30%. Results indicated significant differences in expression of TLR4 between GD patients before treatment, after achieving euthyroid state and in the control group (p< 0.0001). In conclusion, the present study showed a higher expression of TLR4 on monocytes among newly diagnosed GD patients in comparison to normal individuals. TLR4 expression on monocytes decreased significantly among GD patients after treatment.