Decrease in CD226 expression on CD4+ T cells in patients with endometriosis

Endometriosis is a chronic inflammatory disease. The immune-checkpoint molecules CD226 and TIGIT play an important role in regulating T cells' function. However, little is known about the proportion and function of CD226 and TIGIT on CD4+ T cells in endometriosis. The current study found no significant differences in the TIGIT percentage on peripheral CD4+ T cells between patients with endometriosis and the control group. However, CD226 was lower in patients with endometriosis than that in the control group (P < 0.01). The cytokines TNF-α, IL10, and IFN-γ were significantly elevated in TIGIT+ CD4+ T cells compared to TIGIT- CD4+ T cells. HLA-DR+ cells were more numerous among TIGIT+ CD4+ T cells than among the TIGIT- subset (P