Prediction of endometriosis with serum and peritoneal fluid markers: a prospective controlled trial

TLDR

The markers must be validated in a larger study before they can serve as a non‑surgical diagnostic tool. The study aimed to assess whether serum and peritoneal fluid markers could non‑surgically predict endometriosis. Serum and peritoneal fluid from 130 women undergoing laparoscopy were analyzed for six cytokines and reactive oxygen species, and compared across diagnostic groups. Serum IL‑6 and peritoneal fluid TNF‑α distinguished endometriosis patients from controls, with PF TNF‑α ≥15 pg/ml yielding 100 % sensitivity and 89 % specificity, and serum IL‑6 ≥2 pg/ml giving 90 % sensitivity and 67 % specificity.

Abstract

BACKGROUND: The objective of this prospective controlled trial was to investigate the ability of a group of serum and peritoneal fluid (PF) markers to predict, non-surgically, endometriosis. METHODS AND RESULTS: Serum and PF samples were obtained from 130 women while undergoing laparoscopy for pain, infertility, tubal ligation or sterilization reversal. Concentrations of six cytokines [interleukin (IL)-1β, IL-6, IL-8, IL-12, IL-13 and tumour necrosis factor (TNF)-α] were measured in serum and PF, and reactive oxygen species (ROS) in PF, and levels were compared among women who were allocated to groups according to their post-surgical diagnosis. Fifty-six patients were diagnosed with endometriosis, eight with idiopathic infertility, 27 underwent tubal ligation or reanastomosis (control group) and 39 were excluded due to bloody PF. Only serum IL-6 and PF TNF-α could be used to discriminate between patients with and without endometriosis with a high degree of sensitivity and specificity (P < 0.001). A threshold of 15 pg/ml PF TNF-α provided 100% sensitivity and 89% specificity (positive likelihood ratio of 9.1 and negative likelihood ratio of 0). A threshold of 2 pg/ml for serum IL-6 provided a sensitivity of 90% and specificity of 67% (positive likelihood ratio of 2.7 and negative likelihood ratio of 0.14). CONCLUSIONS: By measuring serum IL-6 and PF TNF-α, it was possible to discriminate between patients with endometriosis and those without. Before these markers can be used as a non-surgical diagnostic tool, these data should be verified in a larger study.