Differential expression of L-selectin ligand in the endometrium during the menstrual cycle

Objective: To evaluate the expression of L-selectin ligand in the endometrium during the menstrual cycle. Design: Retrospective study. Setting: University teaching hospital. Patient(s): Endometrial samples from regularly cycling women. Intervention(s): Tissue microarray and immunohistochemical staining were performed using L-selectin ligand monoclonal antibody (MECA-79). Main Outcome Measure(s): Expression of L-selectin ligand in the various phases of menstrual cycle was measured by a semiquantitative analysis (HSCORE) for the intensity of immunohistochemical reactivity. Result(s): In the luminal epithelium, there were significant differences in L-selectin ligand expression during the proliferative, interval, early secretory, and midsecretory phases. The expression of L-selectin ligand was greatest from the periovulatory interval through midsecretory phase. In the glandular epithelium, the expression of L-selectin ligand was greatest in midsecretory phase with significant differences between proliferative phase and the midsecretory phase and between the interval phase and the midsecretory phase. Conclusion(s): Increased expression of L-selectin ligand in the human endometrium during the early and midsecretory phases of the menstrual cycle may be related to the process of implantation.