Problem: Sperm interaction with the immune system of the human cervix is poorly understood.
Method: The leukocytic response of the human cervix to sperm was examined in a closely monitored patient population (N = 10), using monoclonal antibody cell identification techniques. Baseline data were collected from both cervical mucus and smears sampled before treatment by donor insemination. Donor insemination was timed to coincide with ovulation by monitoring plasma LH concentrations twice daily. Following insemination the numbers of leukocytes were recorded in cervical mucus and smear samples taken over a 24-h period relative to the time of treatment. Controls treated with "pure sperm," seminal plasma, cryopreservative, and cervical smearing alone were also included in the study.
Results: Only those women treated with sperm cells exhibited substantial elevations in leukocyte numbers following inseminations. Additionally, serial cervical smearing induced an inflammatory response of the cervix. In all the women, the neutrophil was the predominant leukocyte of the cervix both during the baseline and treatment periods (median values ranged from 77 to 86%). Macrophages, T-helper lymphocytes, and T-suppressor lymphocytes were also detected, but only in low numbers (2-10.6%). Two patients and one control ("pure sperm") became pregnant during their study cycle.
Conclusions: We conclude that the leukocytic reaction is a physiological response of the cervix to sperm, the function of which remains to be established.