LEUKOCYTES IN NORMAL-CYCLING HUMAN OVARIES - IMMUNOHISTOCHEMICAL DISTRIBUTION AND CHARACTERIZATION

We investigated, using an image analysis system, the immunohistochemic al localization of leukocyte subpopulations and human leukocyte antige n (HLA)-DR in 30 normal-cycling human ovaries in order to better under stand local immunological events in human ovaries. All subtypes of T l ymphocytes examined (CD3(divided by), CD4(+) and CD8(divided by) cells ) were sporadically observed in the stroma and theca layers of follicl es throughout the menstrual cycle (ranging from 4.32 to 6.25 cells/10( -7) m(2), 1.67 to 3.33 cells/10(-7) m(2) and 2.33 to 3.44 cells/10(-7) m(2), respectively for the three subtypes), and subsequently, increas ed in number in atretic follicles (78.70 +/- 6.90, 31.13 +/- 2.54 and 43.31 +/- 3.35), After ovulation, the number of T lymphocytes was mark edly low in the early and mid corpus luteum (13.88 +/- 1.62, 4.18 +/- 0.50 and 6.53 +/- 0.45). The number increased in the late corpus luteu m, and was highest in the late degenerating corpus luteum (255.67 +/- 27.10, 102.12 +/- 7.80 and 137.34 +/- 12.50). HLA-DR was sporadically positive in fibroblasts in the stroma and theca layers of follicles (m eans ranged from 1.25 to 1.82 cells/10(-7) m(2)), and increased in atr etic follicles (24.68 +/- 2.25). HLA-DR+ cells were markedly low in th e early and mid corpus luteum (2.16 +/- 0.88), increased in the late c orpus luteum, and reached a plateau in the late degenerating corpus lu teum (121.84 +/- 17.73). The great majority of these increased HLA-DR cells were macrophages. Results of our study suggest that T lymphocyt es and/or macrophages play important roles in luteal regression and fo llicular atresia in normal-cycling human ovaries.