The Abnormal Expression of B7-H4 Is Associated With the Pathogenesis of Autoimmune Thyroid Diseases

B7-H4 is an immunosuppressive molecule extensively studied in tumor diseases and is also of interest in some autoimmune diseases. However, the relationship between B7-H4 and autoimmune thyroid diseases (AITDs) has not been explored.

To investigate the B7-H4 expression in different tissues of patients with different subtypes of AITDs.

The B7-H4 protein expression in thyroid tissue of the participants was identified through immunohistochemical analyses while concentrations of plasma soluble B7-H4 (sB7-H4) were detected by enzyme-linked immunosorbent assay (ELISA). Additionally, B7-H4 mRNA expression in peripheral blood mononuclear cells (PBMCs) was evaluated via RT-PCR.

The immunohistochemical findings revealed a decrease in levels of B7-H4 protein in thyroid tissue of Graves' disease (GD) and Hashimoto's thyroiditis (HT) patients, compared with those of the normal controls. Similarly, a decrease was observed in the level of B7-H4mRNA expression in PBMCs assayed via RT-PCR. However, based on ELISA results, plasma levels of sB7-H4 were increased in both GD and HT patients compared to those in normal controls.

The abnormal expression of B7-H4 in AITD patients suggests that it may be involved in the onset and progression of the disease. At the same time, the mechanism of action of B7-H4 in AITD and whether it is a potential therapeutic target need to be further studied.