Diagnostic performance of hematological inflammatory biomarkers for assessing endometriosis severity and pelvic pain severity

Abstract

Endometriosis is a chronic inflammatory disease frequently associated with pelvic pain and infertility. Since systemic inflammation may reflect disease activity, hematological inflammatory biomarkers obtained from routine blood tests have been proposed as non-invasive indicators of endometriosis severity. The aim of this study was to evaluate the association of the neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), systemic immune-inflammation index (SII), and monocyte-to-lymphocyte ratio (MLR) with endometriosis severity and pelvic pain severity, as well as to assess their diagnostic performance. A cross-sectional study was conducted at Dr. Zainoel Abidin Hospital, Banda Aceh, Indonesia, among women with histopathologically confirmed endometriosis. Endometriosis severity was classified intraoperatively according to the revised American Society for Reproductive Medicine (rASRM) staging system. Pelvic pain severity was assessed preoperatively using the Numeric Rating Scale (NRS). Hematological inflammatory biomarkers were calculated from preoperative complete blood count results. The associations and diagnostic performance of the biomarkers in relation to endometriosis severity and pelvic pain severity were evaluated using correlation analysis and receiver operating characteristic (ROC) curve analysis. Our data indicated that NLR (r=0.460; p<0.001), SII (r=0.439; p=0.001), and MLR (r=0.391; p=0.003) had significant positive correlations with endometriosis severity, whereas PLR demonstrated a borderline correlation (r=0.261; p=0.050). ROC analysis showed good diagnostic performance for NLR (AUC=0.784; p=0.005), SII (AUC=0.777; p=0.006), and MLR (AUC=0.783; p=0.005), while PLR was not statistically significant (AUC=0.679; p=0.078). NLR (r=0.295; p=0.026) and SII (r=0.275; p=0.038) showed weak but significant positive correlations with pelvic pain severity, whereas PLR and MLR had no significant association. None of the biomarkers demonstrated significant diagnostic performance for pelvic pain severity. NLR, SII, and MLR may serve as accessible and inexpensive adjunctive indicators of endometriosis severity, particularly in resource-limited settings; however, their utility for assessing pelvic pain severity appears limited.