Purpose: The objective of the current study was to evaluate whether the analysis of different proinflammatory and angiogenesis-regulating cytokines in a well-defined patient population can be accurate for the diagnosis of endometriosis at different stages.
Material and methods: For this prospective study, plasma samples were collected from women undergoing laparoscopic surgery for subfertility. The stage of endometriosis was confirmed during laparoscopy.
Results: Plasma levels of interleukin 6 (IL-6), carbohydrate antigen (CA)-125 were significantly higher in women with endometriosis compared with controls (46.70 ±27.08 vs. 27.08 ±16.29, p < 0.05; 49.39 ±28.32 vs. 9.78 ±3.87, respectively). In women with minimal-mild endometriosis, only the plasma level of IL-6 was increased (56.45 ±23.21 vs. 27.08 ±16.29, p < 0.05). In women with moderate-severe endometriosis, plasma levels of IL-6 and CA-125 were significantly increased, and those of Epo and tumor necrosis factor α (TNF-α) were significantly decreased (44.53 ±31.07 vs. 27.08 ±16.29,
p < 0.05; 57.84 ±61.44 vs. 9.78 ±3.87, p < 0.05; 26.60 ±10.19 vs. 30.32 ±7.94, p < 0.05; 58.61 ±7.93 vs. 65.40 ±9.86, p < 0.05, respectively). The area under curve (AUC) for Epo, TNF-α, IL-6 and CA-125 were 0.280, 0.322, 0.729 and 0.864, respectively.
Conclusions: The results of our study show that progression of endometriosis is associated with the elevated level of serum IL-6. Clearly, larger prospective studies are required to determine the diagnostic potential of measuring circulating inflammatory cytokine levels like IL-6 in endometriosis.