Menstrual cycle-dependent alterations in glycosylation: a roadmap for defining biomarkers of favorable and unfavorable mucus

Objective To understand glycosylation of endocervical proteins at different times throughout the menstrual cycle in naturally cycling women and in women using hormonal or non-hormonal contraceptive methods, in order to characterize biochemical fingerprints of favorable and unfavorable cervical mucus. Design Lectin/antibody-probed protein blot analysis of endocervical mucus samples collected onto ophthalmologic sponges (wicks) from two groups: a longitudinal cohort of naturally cycling women at three time points in their menstrual cycles (discovery cohort), and a cross-sectional cohort of women on hormonal or non-hormonal contraceptive methods (validation cohort). Setting Participants were recruited from the San Francisco Bay Area from 2010 to 2016. Patient(s) Women with regular cycles not using hormonal or intrauterine device (IUD) contraceptives were recruited for the longitudinal cohort ( n = 8). Samples from women using levonorgestrel-containing combined oral contraceptives ( n = 16), levonorgestrel containing IUDs ( n = 14), copper IUDs ( n = 17), depo-medroxyprogesterone acetate (DMPA) ( n = 15), and controls ( n = 13) were used for validation. Intervention(s) None. Main outcome measure(s) Detection of specific glycosylation patterns on lectin/antibody probed protein blots. Result(s) Two lectins ( Lens culinaris agglutinin and Lycopersicon esculentum [tomato lectin]), and the antibody MECA-79 demonstrated consistent cycle-dependent changes in protein binding. The glycan-binding patterns of the levonorgestrel-containing contraceptives were generally similar to each other and to those from women in the luteal phase. The DMPA samples showed slightly different binding patterns. Conclusion(s) We identified molecular signatures of unfavorable mucus from women in the luteal phase and on hormonal contraceptives. Further characterization of these biomarkers may be useful in contraceptive development and in evaluation of infertility.