Proteomic analysis of serum yields six candidate proteins that are differentially regulated in a subset of women with endometriosis

Abstract

Objective: To identify potential novel biomarkers that differ between subjects with and without endometriosis and that might aid in developing a noninvasive, serum-based diagnostic test.

Design: Case-control evaluation of a diagnostic test.

Setting: University medical center.

Patient(s): Consenting women of reproductive age undergoing laparoscopy for indications of pain, infertility, elective tubal ligation, tubal reanastomosis, or other benign indication.

Intervention(s): Diagnostic laparoscopy and peripheral venipuncture.

Main outcome measure(s): Concentrations of low-molecular-weight proteins in serum; surgical staging of endometriosis.

Result(s): Six proteins were found that were differentially expressed between those with and without disease and that had good diagnostic properties. Taken together in a two-step diagnostic algorithm, we were able to diagnose 55% of subjects, with 99% accuracy as to the status of disease. Further combining this algorithm with that derived by our previous study of serum putative markers (monocyte chemoattractant protein-1, migration inhibitory factor, leptin, and CA-125) improved our diagnostic capability to 73% of subjects, with 94% overall accuracy.

Conclusion(s): This study is the critical first step in the identification of potential novel biomarkers of endometriosis. Future identification of the proteins and further validation in a second population is needed before applying these findings in clinical practice.