Introduction/Background Maintaining the metabolic processes in lymphocytes (LF) is one of the conditions for their effective functioning. The purpose of the study was to analyze the antioxidant defense in tumor-infiltrating LF and blood LF of patients with ovarian cancer (OC).

Methodology Levels of A and E vitamins and activity of catalase (C), SOD and glutathione peroxidase (GP) were determined by ELISA in LF isolated from malignant ovarian tissues and blood of patients with OC T_3-4N_xMx.

Results The amount of LF in tumors was 1.5 times higher than in intact ovarian tissues, while protein amount in them was 1.8 times lower. E and A vitamins in tumor LF were 3.1 times lower than in intact ovaries, and their ratio did not change. C activity in tumor LF was 2.1 times lower, SOD and GP were similar to control values, but a natural enzyme cascade characterized by their ratio was 1.9 times higher than in intact organs.

The amount of LF in the blood of OC patients was similar to the norm, while protein amount in them was 1.8 times higher. Levels of E and A vitamins in blood LF in patients were 2.4 and 4.1 times lower, and their ratio was 1.8 times higher than in healthy donors. SOD activity was 2 times lower than in donors, and GP was 6 times higher. The SOD/GP ratio was 3 times higher than in the blood of healthy people.

Conclusion Tumor-infiltrating LF in ovarian cancer demonstrated disrupted natural cascade of antioxidant enzymes with the suppression of C activity. This may result in hyperproduction of superoxide anion radical in cells leading to self-poisoning of lymphocytes by active oxygen species. Low levels of E and A vitamins playing an important role in the maturation of immunocompetent cells can be the main cause of lymphocyte functional failure.

Disclosure Nothing to disclose.