Expression of interleukin-1 (IL-1) beta messenger ribonucleic acid (mRNA) and IL-1 receptor antagonist mRNA in peritoneal macrophages from patients with endometriosis.

OBJECTIVE: To investigate the expression of interleukin-1 (IL-1) beta messenger ribonucleic acid (mRNA) and IL-1 receptor antagonist (IL-1ra) mRNA in peritoneal macrophages.

DESIGN, SETTING: Peritoneal fluid (PF) samples were collected from patients who underwent laparoscopy or laparotomy. Northern blot analysis was performed at the reproductive research laboratory.

PATIENTS: Twenty-six patients with endometriosis, 10 patients with postinflammatory pelvic adhesion, and 12 control women with normal pelvis.

MAIN OUTCOME MEASURE: Polyadenylated RNA isolated from peritoneal macrophages was analyzed on Northern blots by using synthetic oligonucleotide probes.

RESULTS: The level of IL-1 beta mRNA expression was elevated in the group with stage I endometriosis, whereas the increased expression of IL-1ra mRNA was observed in the group with stages III and IV endometriosis. The level of IL-1 beta mRNA showed a positive correlation with that of IL-1 beta in PF and a negative correlation with the level of IL-1ra mRNA.

CONCLUSIONS: Our results suggest that peritoneal macrophages express IL-1ra mRNA rather than IL-1 beta mRNA with the progress of endometriosis and that peritoneal macrophages may secrete IL-1ra protein that modulates the effects of IL-1.