Background: Endometriosis is a debilitating gynecologic disease causing severe pelvic pain. About 1/3 of patients suffer from chronic pelvic pain unresponsive to conventional treatment. Here, we identified plasma proteins associated with persistent pelvic pain following laparoscopic surgery in adolescents and young adults with endometriosis.

Methods: We conducted a prospective analysis in 142 laparoscopically-confirmed endometriosis cases from the Women’s Health Study: From Adolescence to Adulthood longitudinal cohort. In blood collected pre-surgery, we measured 1,305 plasma protein levels simultaneously using SOMAscan. We calculated odds ratios and 95% confidence intervals using logistic regression adjusted for age, body mass index, fasting status, and hormone use for differentially expressed proteins. We applied Ingenuity Pathway Analysis to identify biological pathways.

Results: One-year post-surgery, pelvic pain worsened/persisted for 76(54%) endometriosis cases while pelvic pain improved for 66(46%). We identified 94 proteins associated with risk of worsening/persistent pelvic pain one-year post-surgery. Pathways related to cell movement, inflammatory response were upregulated and pathways related to angiogenesis were downregulated in endometriosis cases with worsening/persistent post-surgical pelvic pain compared to those with improved pain.

Conclusions: Using a comprehensive proteomics platform, we identified plasma proteins and pathways associated with persistent post-surgical pelvic pain, providing novel biological insight in persistent post-surgical pain development.