Abnormal ratio of CD 57+ cells to CD 56+ cells in women with recurrent implantation failure

PROBLEM: To define a more precise parameter for a better understanding of natural killer (NK) cells and its relation with regulatory T cells (Tregs) in women with recurrent implantation failure (RIF). METHOD OF STUDY: The percentages of CD56+ cells, CD57+ cells and Foxp3+ cells in the endometrium and blood from 23 normal controls and 32 women with RIF were measured by immunocytochemistry and flow cytometry. RESULTS: Women with RIF had significantly increased ratio of CD57+ cells to CD56+ cells in both the endometrium (P<.01) and blood (P<.05), and decreased percentage of Foxp3+ cells in the endometrium (P<.05). There was a significant negative correlation between CD57+ cells to CD56+ cells ratio and the percentage of Foxp3+ cells in the blood of RIF patients (P<.05). CONCLUSION: Our study provides a novel assessment parameter, CD57+ cells to CD56+ cells ratio, to evaluate NK cells and its relation with Tregs in RIF patients.