AGE-RELATED SPECIFICITIES OF ENDOMETRIAL PROLIFERATION/STEM CELL INDEX DISTRIBUTION

Endometrial stem cells take the special place among somatic stem cells of female reproductive system, since their essence and nature still remains unclear - cellular complexity of endometrium, its hormone-dependence and cycling remodeling makes the study of endometrial stem cells exclusively complicated. Consequently, the detection of endometrial stem cells and identification of their location in the complex cellular hierarchy still remains challenging. The aim of our study was to explore the age-related specificities of endometrial proliferative / stem cell index distribution under normal and hyperplasia conditions. The study represents a retrospective research. The coded and depersonalized material data from Acad. N. Kipshidze Central University Clinic was used in the study. 2 study groups - 1st study group "Norm" (12 cases) and 2nd study group "Endometrial Hyperplasia" condition (18 cases) were selected from routine histopathology tissue specimens of uterus. Hematoxilyn-eosin technology and immunohistochemistry with proliferation marker Ki67 and stem cell marker CD146 was performed. The proliferative/stem cell index was calculated by the ratio of Ki67-positive cell percentage value divided by CD146-positive cell percentage value. The study showed that in the 1st study group labeled as "norm", the proliferative/stem cell index ranges between 8 and 16.5. Its mean average value in the age distribution subgroups accounts for: 1.1) reproductive age - 10.6; 1.2) menopause - 4.5; 1.3) post-menopause - 1. In the 2nd study group labeled as "endometrial hyperplasia", the proliferative/stem cell index markedly increases and ranges within the interval 15-23. Its mean average value in the age distribution subgroups accounts for: 2.1) reproductive age - 18; 2.2) menopause - 18.2; 2.3) post-menopause - 18.5. It was found that proliferative/stem cell index in the 1st study group labeled as "Norm" progressively decreases with aging, while in the 2nd study group labeled as "Endometrial Hyperplasia" it behaves opposite and increases with age. Moreover, it must be noted that proliferative/stem cell index in endometrial hyperplasia cases with regard to norm increases significantly, namely in the subgroups 1.1/1.2 (which is reproductive age) it increases 1.5 times, and in the subgroups 1.2/2.2 (which is menopause age) it increases 2.5 times, while in the subgroups 1.3/2.3 (which is post-menopause age) it increases 18.5 times. The high attention should be given to the fact that the mean average value of proliferative/stem cell index in endometrial hyperplasia most markedly differs from the norm in post-menopause period.