The aim of our study was to investigate the prevalence of PD-L1, PD-L2 expression on antigen-presenting cells (e.g., myeloid and plasmacytoid DCs) in the peripheral blood (PB) and peritoneal fluid (PF) of women with EMS, and its correlation with clinical characteristics of EMS patients. Here, PDCD1LG2 is linked to eosinophilia-myalgia syndrome.