LOCALIZATION OF LEUKOCYTE SUBSETS IN THE FOLLICLE WALL AND IN THE CORPUS-LUTEUM THROUGHOUT THE HUMAN MENSTRUAL-CYCLE

Objective: To determine the presence and localization of leukocyte sub sets in the human follicular wall and in the corpus luteum (CL) throug hout the menstrual cycle. Design: Tissue was obtained by biopsy at lap aroscopy. Frozen sections were labeled with a panel of monoclonal anti bodies against leukocyte subtype markers and detected by immunohistoch emical methods. Setting: Infertility clinic in large teaching hospital . Patients: Eighteen women who underwent diagnostic laparoscopy. Women with abnormal endocrinology, endometriosis, or ovarian disease were e xcluded. Results: Macrophages and neutrophilic granulocytes were prese nt in high numbers in the collagen-rich tissues, including the thecal layer, of the follicle wall. At ovulation, there was a marked increase in the density of these cells in the follicle wall, especially in the thecal layer. In the CL, there was a higher density of macrophages (2 - to 3-fold) and neutrophils (3- to 5-fold) in the theca lutein area c ompared with the granulosa lutein area. There were no significant chan ges in the density of these cell types when early and late luteal phas e were compared, but the density of macrophages were markedly elevated in regressing CLs obtained during the subsequent follicular phase. T lymphocytes were present in low numbers in the follicle wall and in th e CL, and no variation in the density was detected throughout the mens trual cycle. Conclusion: Macrophages and neutrophilic granulocytes are present in high numbers in the follicle wall and are further increase d in the theca at ovulation, suggesting an active role for these leuko cyte subtypes in tissue remodeling during the ovulatory process. Macro phages and neutrophils are also abundant in the CL, and an increase in the macrophage density at CL regression could imply a role for these cells in luteolysis.