Levels of oestrogen receptor, progesterone receptor and αB-crystallin in eutopic endometrium in relation to pregnancy in women with endometriosis.

Endometriosis affects fertility in many women and may partly be due to decreased endometrial receptivity. Several mechanisms have been suggested, notably, progesterone resistance for which a number of candidate biomarkers have been suggested. Here we demonstrate aberrant levels of steroid hormone receptors and the small heat shock protein αB-crystallin in eutopic endometrial epithelium from 38 women with peritoneal endometriosis diagnosed during investigation for secondary infertility. Spontaneous pregnancies within 1 year after medical and surgical treatment for endometriosis were recorded and semi-quantitative immunohistochemistry data compared between women with endometriosis who did or did not become pregnant and healthy controls. Stronger immunostaining for ER-α was detected in luminal and glandular endometrial epithelium from women with endometriosis who did not become pregnant during the post-treatment observation period versus endometriosis patients who became pregnant and controls. Staining levels of PR and PR-B were lower in patients without subsequent pregnancies than in the two other groups. Endometrial levels of αB-crystallin in endometriosis patients similar to those in controls were strongly correlated with the chance of becoming pregnant, whereas higher or lower levels were not.