Norah Spears and Andrew W Horne
Douglas A Gibson, Frances Collins, Bianca De Leo, Andrew W Horne, and Philippa T K Saunders
Endometriosis is a chronic neuroinflammatory pain condition affecting ~180 million women worldwide. Surgical removal or hormonal suppression of endometriosis lesions only relieves pain symptoms in some women and symptomatic relapse following treatment is common. Identifying factors that contribute to pain is key to developing new therapies. We collected peritoneal fluid samples and clinical data from a cohort of women receiving diagnostic laparoscopy for suspected endometriosis (n=52). Peritoneal fluid immune cells were analysed by flow cytometry and data compared with pain scores determined using the pain domain of the Endometriosis Health Profile Questionnaire (EHP-30) in order to investigate the association between peritoneal immune cells and pain symptoms. Pain scores were not different between women with or without endometriosis, nor did they differ according to disease stage; consistent with a poor association between disease presentation and pain symptoms. However, linear regression and correlation analysis demonstrated that peritoneal macrophage abundance correlated with severity of pelvic pain. CD14high peritoneal macrophages negatively correlated with pain scores whereas CD14low peritoneal macrophages were positively correlated, independent of diagnostic outcome at laparoscopy. Stratification by pain subtype, rather than endometriosis diagnosis, resulted in the most robust correlation between pain and macrophage adundance. Pain score strongly correlated with CD14high (p=0.007) and CD14low (p=0.008) macrophages in patients with non-menstrual pain and also in patients who reported dysmennorhea (CD14high p=0.021, CD14low p=0.019) or dysparunia (CD14high p=0.027, CD14low p=0.031). These results provide new insight into the association between peritoneal macrophages and pelvic pain which may aid identification of future therapeutic targets.
Elizabeth Ball, Babu Karavadra, Bethany Jade Kremer-Yeatman, Connor Mustard, Kim May Lee, Sharandeep Bhogal, Julie Dodds, Andrew W Horne, John Allotey, and Carol Rivas
Background: Up to 28% of endometriosis patients do not get pain relief from therapeutic laparoscopy but this subgroup is not defined.
Objectives: To identify any prognostic patient-specific factors (such as but not limited to patients’ type or location of endometriosis, sociodemographics and lifestyle) associated with a clinically meaningful reduction in post-surgical pain response to operative laparoscopic surgery for endometriosis.
Search strategy: PubMed, Cochrane and Embase databases were searched from inception to 19th May 2020 without language restrictions. Backward and forward citation tracking was used.
Selection criteria, data collection and analysis: Cohort studies reporting prognostic factors, along with scores for domains of pain associated with endometriosis before and after surgery, were included. Studies that compared surgeries, or laboratory tests, or outcomes without stratification were excluded. Results were synthesised but variation in study designs and inconsistency of outcome reporting precluded us from doing a meta-analysis.
Main results: Five studies were included. Quality assessment using the Newcastle Ottawa Scale graded three studies as high, one as moderate and one as having a low risk of bias.
Four of five included studies separately reported that a relationship exists between more severe endometriosis and stronger pain relief from laparoscopic surgery
Conclusion: Currently there are few studies of appropriate quality to answer the research question. We recommend future studies report core outcome sets to enable meta-analysis.
Funding: NIHR PB-PG-0317-20018
Keywords: endometriosis, laparoscopy, systematic review, surgery