Background: To clarify the inflammatory nature of adenomyosis, we aimed to investigate the expression of interleukin-8 (IL-8) and monocyte chemotactic protein-1 (MCP-1) by immunohistochemistry to determine their putative role in pathophysiology of adenomyosis.
Methods: Adenomyosis samples, with their eutopic endometrium, were collected from 30 women undergoing hysterectomy. Endometrium from 27 women without adenomyosis were also collected as a control group. Samples were grouped according to the menstrual cycle phase and examined by immunohistochemistry for IL-8 and MCP-1.
Results: In normal endometrium, secretory phase samples expressed higher levels of epithelial IL-8 than in proliferative phase samples (P = 0.01), and we observed a trend for an increased epithelial MCP-1 expression in the secretory phase samples compared with the proliferative phase samples (P = 0.07). Endometrial samples of women with adenomyosis did not show the same cyclic variation. In the secretory phase, eutopic endometrium of women with adenomyosis expressed lower levels of epithelial IL-8 and MCP-1 compared with normal endometrium (P < 0.05). The expression of epithelial IL-8 and MCP-1 was higher in the adenomyosis foci than the eutopic endometrium (P < 0.05).
Conclusions: These findings may indicate that an intrinsic abnormality of inflammatory response may be present in eutopic endometrium of women with adenomyosis, and IL-8 and MCP-1 may contribute to the pathophysiology of adenomyosis.