Quantity and quality of retrograde menstruation: a case control study

Area of Science:

• Gynecology
• Reproductive Biology
• Cell Biology

Background:

• Endometrial cells in peritoneal fluid (PF) and changes in PF cell counts during the menstrual cycle are not fully understood.
• Investigating the presence of endometrial cells and inflammatory markers in PF is crucial for understanding gynecological conditions.

Purpose of the Study:

• To test if menstruation is associated with higher concentrations of endometrial cells and increased white and red blood cells in PF compared to non-menstrual phases.
• To evaluate the presence and origin of cells in PF using immunocytochemistry.

Main Methods:

• Peritoneal fluid (PF) was collected laparoscopically from women with and without endometriosis during luteal, follicular, and menstrual phases.
• Cell counts (leukocytes, erythrocytes, thrombocytes) were determined, and PF samples were stained for specific cell markers (CK7, CK8/18, Ber-Ep4, vimentin, calretinin, CD68).

Main Results:

• Menstruation was associated with significantly increased concentrations of leukocytes, erythrocytes, hematocrit, and hemoglobin in PF compared to non-menstrual phases.
• Mesothelial cells showed positive staining for CK7, CK8/18, vimentin, and calretinin.
• Cells positive for Ber-Ep4 were rare, observed only in two patients during menses; vimentin and CD68 were positive in 50-98% of single cells.

Conclusions:

• Menstruation is linked to elevated red and white blood cell counts in PF.
• The detection of endometrial cells in PF via immunohistochemistry remains low throughout the menstrual cycle, including during menstruation.