Expression of interleukin-8 and monocyte chemotactic protein-1 in adenomyosis

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.

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.

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).

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.