Evaluation of serum-based inflammatory and haematological markers in patients with endometriosis: A case–control study

Abstract

Objective

To assess the diagnostic value of serum-based inflammatory and haematological markers in women with endometriosis, and determine their relationship with disease severity, including lesion characteristics.

Materials and methods

This prospective study included 103 patients with endometriosis (aged 18–45 years) and 103 healthy controls. Serum C-reactive protein (CRP), albumin and complete blood counts were obtained pre-operatively, and inflammatory markers [neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio, neutrophil-to-platelet ratio (NPAR), CRP-to-albumin ratio (CAR), systemic inflammation index (SII), systemic inflammatory response index (SIRI) and pro-inflammatory index (PIV)] were calculated. Surgical evaluation (laparoscopy/laparotomy) provided histopathological confirmation of endometriosis. The 1996 revised American Society for Reproductive Medicine (rASRM) classification was used for staging. Statistical analyses used t-tests, Mann–Whitney U-tests, Chi-squared tests, Spearman’s correlation, and linear regression modelling. p < 0.05 was considered to indicate significance.

Results

Compared with controls, patients with endometriosis had lower white blood cell (7.28 vs 8.43 × 10³/mm³; p < 0.001), neutrophil (4.17 vs 5.09 × 10³/mm³; p < 0.001) and CRP (2.45 vs 3.34 mg/l; p = 0.008) levels, but higher haemoglobin (12.8 vs 11.9 g/dl; p = 0.001) and haematocrit (40.5 % vs 38.1 %; p < 0.001) levels. NPAR (1.38 vs 1.48; p < 0.001), SII (539 vs 737; p < 0.001), SIRI (1004 vs 1337; p < 0.001), PIV (302 vs 422; p < 0.001), CAR (0.061 vs 0.079; p = 0.008) and NLR (1.89 vs 2.44; p < 0.001) were also significantly lower in patients with endometriosis. Postoperatively, NLR, SIRI, PIV and NPAR increased (p < 0.05). Receiver operating characteristic curve analysis indicated moderate diagnostic performance for neutrophil percentage, NLR, SII, SIRI and PIV. On multi-variate analysis, bilaterality (p < 0.001) and area of endometriomas (p = 0.020) correlated with rASRM score.

Conclusion

Serum inflammatory markers reflect systemic immune changes in endometriosis. Although they offer diagnostic insights, lesion bilaterality and size remain stronger predictors of disease severity. Larger, multi-centre studies are needed to refine cut-off values and optimize clinical application of these markers.