[Investigation on endometrium from menstrual blood as a source of non-invasive tissue]

Objective: To investigate the feasibility of a non-invasive sampling method by collecting menstrual blood and obtaining endometrium for further research in menstruation-related diseases. Methods: On the second day of menstruation, menstrual blood was collected with menstrual cups for 4 hours, and the menstrual endometrium was filtered through a metal screen for weighing, cryopreserved, immunohistochemical staining and cell culture. Results: The collection process was painless and non-invasive. In the control group, the menstrual volume was (9.1±0.7) ml, and the endometrial tissue weight was (91.0±14.7) g. In the endometriosis group, the menstrual volume was (9.6±1.9) ml (P=0.022), and the endometrial tissue weight was (134.7±43.9) g (P=0.057). Endometrial cell culture was successful in all patients and should not be contaminated. The growth curve was a finite cell line type. The expression of cytokeratin 19 and vimentin in menstrual endometrium and cells were positive. Conclusions: By collecting menstrual blood and filtering endometrial tissue, it is an ideal non-invasive sampling method. In combination with advanced experimental technology, menstrual endometrium make further researches of endometriosis, endometrial lesions or other menstruation-related diseases possible.