[A study on oxidative DNA damage and lipid peroxidation in patients with tuberculous pleurisy].

OBJECTIVE

To explore the levels of mononuclear cell oxidative DNA damage and lipid peroxidation in patients with tuberculous pleurisy.

METHODS

The mononuclear cell DNA damages in pleural effusion and peripheral blood of 28 patients with tuberculous pleurisy and in peripheral blood of 25 healthy persons were detected by single cell gel electrophoresis (comet%). The levels of total antioxidative capacity (TAC) in supernatant of pleural effusion and blood plasma of 28 patients and in blood plasma of 25 healthy persons were measured by o-phenanthroline colorimetric analysis. The contents of malondialdehyde (MDA) of blood plasma from 28 patients and from 25 healthy persons were measured by thiobarbituric acid colorimetric analysis. The differences between groups were analyzed by t test.

RESULTS

The comet percentage of mononuclear cells in pleural effusion from patients with tuberculous pleurisy was (41.3 +/- 14.5)%, which was significantly higher than that in the peripheral blood (21.2 +/- 4.2)% (P < 0.01); The level of TAC in supernatant of pleural effusion was (5 172 +/- 1 195) U/L, which was lower than that in the blood plasma (8 656 +/- 1 592) U/L (P < 0.01). There was a negative correlation between the comet percentage of mononuclear cells and the level of TAC (r = -0.425, P < 0.05) in pleural effusion. The comet percentage of mononuclear cells in peripheral blood and the content of MDA in blood plasma from patients were (21.2 +/- 4.2)% and (8.25 +/- 1.37) micro mol/L, which were significantly higher than those from the controls (8.9 +/- 3.7)% and (4.46 +/- 0.93) micro mol/L respectively (P < 0.01); The level of TAC in blood plasma was (8 656 +/- 1 592) U/L, which was lower than that from the controls (10 610 +/- 1 399) U/L (P < 0.01). There were negative correlations between the level of TAC in blood plasma and the comet percentage of mononuclear cells in peripheral blood or the content of MDA in blood plasma (r = -0.438, -0.413, P < 0.05), and there was a positive correlation between the comet percentage of mononuclear cells in peripheral blood and the content of MDA in blood plasma (r = 0.899, P < 0.01).

CONCLUSION

There is oxidation/antioxidation imbalance in patients with tuberculous pleurisy, namely oxidative stress, with inadequate total antioxidative capacity, particularly in the diseased pleural cavity.