Altered apoptosis and proliferation in endometrial stromal cells of women with adenomyosis.

BACKGROUND The eutopic endometrium in a woman suffering from adenomyosis is known to be biologically different from that of healthy women. The aim of this study was to examine the apoptosis and proliferation of eutopic endometrium from women with adenomyosis. METHODS We enrolled 23 women with adenomyosis (study group) and 21 without (control group). Eutopic endometrium was obtained and separated into single endometrial stromal cells (ESCs). ESCs were treated in vitro with hydrogen peroxide (H(2)O(2)) to examine their apoptosis using a fluorescence-activated cell sorter. Cells were also treated with estradiol (E(2)), medroxyprogesterone acetate, interleukin (IL)-6, lipopolysaccharide and interferon-gamma (IFN-gamma) to test their proliferation using a non-radioactive cell proliferation assay. RESULTS The percentage of annexin V ( + )/7-amino-actinomycin D ( + ) ESCs was much lower in women with adenomyosis after 24 h culture with and without H(2)O(2) treatment when compared with the control group. ESCs of adenomyosis proliferated more rapidly than those of the control group, whether they were cultured alone or were treated with E(2), MPA, IL-6 or IFN-gamma. The immunocytochemical Ki-67 labelling index was much more prominent in adenomyotic ESCs than that of the control group (7.7% versus 1.1%, P < 0.001). CONCLUSIONS Altered apoptosis and proliferation of eutopic endometrium possibly elucidate some aspects of the pathophysiology of adenomyosis. A high Ki-67 labelling index in immunocytochemistry might be a potential indicator in predicting the occurrence of adenomyosis.