Reduced percentage of natural killer cells associated with impaired cytokine network in the secretory endometrium of infertile women with polycystic ovary syndrome.

Objective: To evaluate lymphocyte subset distribution in the secretory endometrium from infertile patients with polycystic ovary syndrome (PCOS), and the expression of the cytokines known to play a role in determining the endometrial lymphocyte pattern.
Design: Experimental clinical study.
Setting: Outpatient clinic in a university hospital.
Patient(s): Twenty-eight patients with PCOS (PCOS group) and 6 fertile patients (control group).
Intervention(s): On days 22-26 of a spontaneous cycle, subjects underwent endometrial biopsies.
Main Outcomes Measure(s): In 19 of 28 patients with PCOS and 6 controls with a late secretory endometrium, the percentage and phenotype of lymphocyte subsets were analyzed by flow cytometry. In the late secretory endometrium of 11 patients with PCOS and 3 controls, the expression of interleukins 15 and 18 and of chemokine ligand 10 was also analysed by polymerase chain reaction.
Result(s): In patients with PCOS the percentage of CD56+/CD16- and of CD56bright/CD16- cells was significantly lower (median [confidence interval]: 38% [31%-52.7%] vs. 63.7% [57.7%-69%] and 17.4% [8%-41.6%] vs. 52% [43%-60%], respectively), whereas the percentage of CD3+ was significantly higher (45% [33.3%-64%] vs. 26.1% [21%-32%]) as compared with controls. Accordingly, polymerase chain reaction analysis revealed a significantly lower expression of interleukins 15 and 18 and of chemokine ligand 10 in patients with PCOS than in controls.
Conclusion(s): Results demonstrated an abnormal percentage of endometrial lymphocyte subsets, associated with an impaired cytokine network in patients with PCOS. This could explain the poor reproductive potential in these patients.
(Copyright © 2010 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.)