ABSTRACT
OBJECTIVE: To determine whether the peripheral blood concentration of CD56(+)/CD16(-)/CD3(-) cells, the main natural killer (NK) subpopulation that colonizes the endometrium in the middle and late secretory phase, can be related to fertility or infertility status. DESIGN: A case control study. SETTING: Immunopathology department of an infertility laboratory. PATIENTS: A total 99 women were selected (group I: consecutive spontaneous aborters, n = 25; group II: sporadic spontaneous aborters, n = 30; group III: infertile, n = 33; group IV: controls, n = 11). INTERVENTION: Immunophenotyping of women grouped according to their fertility status. MAIN OUTCOME MEASURES: Peripheral blood lymphocytes were examined by two- and three-color flow cytometry. RESULTS: A statistically significant association between endometrial-type peripheral blood (PB) NK cell concentrations and fertility status (groups I and IV vs. groups II and III) was documented. The %(/TOTAL PB)(CD56+CD16-CD3-) NK cells was significantly higher [1] in fertile (groups I and IV) than in sporadic aborters/infertile (groups II and III) women, [2] in group I when compared with groups II and III, and [3] in group IV when compared with groups II and III. CONCLUSIONS: This study indicates that diminished numbers of the %(/TOTAL PB)(CD56+CD16-CD3-) NK cells are related to sporadic aborters and infertile women. Thus, the fraction could be used as an indicator of subsequent successful implantation and maintenance of gestation.
