Redox Status in External Genital Endometriosis

Introduction. Oxidative stress is a key factor in external endometriosis. The search for peripheral blood markers is promising due to the lack of non-invasive diagnostics. Existing data are contradictory and require correlation with local changes in lesions.

Aim is to assess the levels of lipid peroxidation (LPO) products and total antioxidant capacity (TAC) in serum, ectopic and eutopic endometrium in patients with endometriosis and to evaluate their potential as diagnostic markers.

Materials and methods. The study included 58 women (control — 10 patients; mild and severe endometriosis — 12 and 36 patients, respectively). Spectrophotometric analysis of tissue homogenates and serum measured lipid peroxidation products: diene conjugates (DC), ketodienes and conjugated trienes (KD&CT), Schiff bases (SB), and TAC. Statistical analysis used Shapiro-Wilk, Levene, Fisher, Kruskal-Wallis, and post hoc Dunnett-Steel-Critchlow-Fligner tests.

Results. In endometrial homogenates, levels of DC, KD&CT and SB were significantly lower than in control. Conversely, serum DC and TAC levels were statistically higher in endometriosis patients. Tissue TAC was decreased, while serum TAC showed a tendency to increase. In homogenates, DC (heptane phase) and KD&CT (isopropanol phase) levels were lower in mild versus severe disease.

Conclusion. In endometriosis, local oxidative stress in tissues is characterized by decreased TAC, indicating antioxidant depletion, while systemic circulation shows elevated DC. The reduced lipid peroxidation in ectopic versus eutopic endometrium may result from the absence of abdominal microbiota and local adaptive mechanisms. These differences in redox status may be used for the diagnosis of the disease.

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