Use of integrins to date the endometrium

OBJECTIVE: To compare traditional histologic dating criteria of the endometrium with immunohistochemical criteria based on epithelial integrin expression during the menstrual cycle. DESIGN: Prospective clinical study. SETTING: An academic teaching hospital. PATIENT(S): Fertile and infertile women undergoing endometrial biopsy. MAIN OUTCOME MEASURE(S): Immunohistochemical staining intensity and distribution (HSCORE) of three integrins and traditional histologic endometrial dating. RESULT(S): In 1,501 endometrial specimens, phase assignment-based integrin staining was 95% and 85% concordant with histology for the proliferative and early secretory phase, respectively, but only 54% and 49% concordant for the middle and late secretory phase, respectively. The greatest disagreement occurred during the midluteal phase. Of 1,090 patients who underwent sampling 6-10 days after detection of a urinary LH surge (corresponding to cycle days 20-24), multiple logistic regression analysis revealed that endometriosis was positively correlated and male factor infertility was negatively correlated with absent beta3 integrin subunit expression. Diagnosis and absent epithelial alpha4beta1 expression were not related. Patient age was not correlated with the incidence of abnormalities in integrin expression. CONCLUSION(S): Traditional histologic dating of the endometrium has remained the gold standard for nearly 50 years. Although the use of marker proteins provides additional information and may reflect endometrial function or receptivity, such markers cannot yet replace traditional methods of endometrial assessment.