Percentage and Absolute Count of Peripheral Blood Natural Killer Cells in Cases of Recurrent Spontaneous Abortion

Immunological processes are most important in recurrent spontaneous abortion(RSA). According to studies T lymphocytes and natural killer cells(NK cells) are two effective cell groups in RSA. The aim of this study was to investigate the percentage and absolute number of natural killer(NK) cells in women with RSA with unknown etiology. 24 Women with a history of recurrent pregnancy losses with unknown etiology. We compared the percentage of peripheral blood NK cells with a group of fertile patients. Lymphocytes from peripheral blood were isolated by ficoll paque density centrifugation. Lymphocytes were stained using anti CD56 and(FITC)-anti CD16 and CYQ-CD3 monoclonal antibodies for identification of NK cells and was used anti CD56 and(FITC)-anti CD69 for detection of activated NK cells. We used BD FACS calibure flow cytometry for data analysis. On the basis of the obtained results, absolute number of CD16+56+ cells showed significant increases in Recurrent spontaneous abortion(RSA) in comparison with control group(P= 0.43). Also absolute number of CD16+56bright cells had significant increase in RSA(P=0.00). There was no significant difference(P= 0.08) of CD16+56dim cells between RSA and control group. In RSA, the absolute number of CD69+cells significantly increased(P=0.02). Also, results showed significant increase in the absolute number of CD56+/CD69+ cells in RSA(P=0.04). The results suggested that the higher percentage of NK cells in peripheral blood of RSA patients compared to control group may indicate the same increase in number and cytotoxicity of uterin NK cells.