Presence of interleukin-8 and the IL-1 receptor antagonist in the cervical mucus of fertile and infertile women.

Background: Cytokines are involved in almost every aspect of reproduction, and recent studies suggested a relationship between cytokines and male/female infertility. In the present study, the levels of interleukin-8 (IL-8) and interleukin-1 receptor antagonist (IL-1Ra) were determined in the cervical mucus of fertile and infertile women.

Methods: Groups of patients were formed according to the results of the standard procedure for infertility investigation, including postcoital test and the presence of antispermatozoid antibodies in the sera of both partners and in seminal plasma, by mixed antiglobulin reaction (MAR) test and Kibrick agglutination test. IL-8 and IL-1Ra levels were determined in solubilized (ultrasonographic sonication) cervical mucus sampled in the midcycle by commercial ELISA kits and expressed as pg/mg proteins.

Results: The groups were designated as fertile (n=20) and infertile (n=48). The latter was divided into two subgroups, one consisting of infertile women with positive postcoital test and without antispermatozoid antibodies (n=30), and the other designated as infertile women with negative postcoital test (n=18). This subgroup was composed of women with negative postcoital test and without antibodies (n=10) and the women with negative postcoital test with antibodies (n=8). Similar levels of IL-8 and IL-1Ra were noted in the cervical mucus of infertile women and women with positive postcoital test and without antispermatozoid antibodies. A tendency of decrease (p=0.052) and significant decrease in IL-8 levels (p<0.05) was noted in negative postcoital test group and negative postcoital test group without antibodies, respectively, compared to the levels in the fertile examinees. A significant rise in IL-1Ra levels (p<0.05) was detected in the mucus of negative postcoital test group with further increase in negative postcoital test group with antibodies (p<0.02).

Conclusion: Changes in IL-8 and IL-1Ra levels in the cervical mucus of infertile patients with negative postcoital test suggested the existence of the relationship between cervical cytokines and infertility in these women.