Endometrial CD 16 + and CD 16 − NK Cell Count in Fertility and Unexplained Infertility

Problem Peripheral counts of CD 16 +  NK cells have been well characterized in reproductive failure. However, not enough case‐control clinical studies have been conducted to establish normal or abnormal CD 16 +/−  values in the endometrium. Method of study Peripheral and endometrial NK cell counts by FACS , IL ‐6, and VEGF cytokines levels by ELISA were characterized in fertile women and unexplained infertility patients with implantation failures ( UI ‐ IF ) during implantation window. ROC and correlation analysis were performed. Results Receiver Operating Characteristic( ROC ) analysis revealed endometrial CD 16 +  NK cells, IL ‐6, and VEGF as good diagnostic parameters for unexplained infertility. Almost half of   UI ‐ FI patients showed increased total and CD 16 +  NK cell counts correlating with decreased levels of endometrial IL ‐6 and VEGF . No correlation was found with peripheral blood values. Conclusion Increased CD 16 +  NK cells were associated with IL ‐6 and VEGF deficiency in a high proportion of UI ‐ IF patients. Testing for these immunomarkers could be a potential tool in infertility diagnosis.