Oxidative stress and immune-suppression in Toxoplasma gondii positive blood donors: implications for safe blood transfusion

ABSTRACT

The sero-markers of Toxoplasma gondii and oxidative stress [OS] were determined in a group of 260 blood donors attending blood banks in Greater Cairo. Twenty-four blood donors with the highest anti-T. gondii IgG titre were tested for IgG avidity. Of whom 4 [16.6%] had low IgG avidity antibodies, documenting recent infection, 6 [25%] had borderline avidity and 14 [58.3%] showed high avidity, ruling out recent infection. The plasma level of malondialdehyde [MDA] was significantly higher and activity of glutathione peroxidase [GSH-Px] and level of tocopherol [alpha, gamma, and lambda] fractions [P < 0.001] were lower in T. gondii-seropositive than in seronegative blood donors. This significant alteration in redox status between seropositive and seronegative donors suggested a degradation of their antioxidant enzymes caused by OS induced by increased free radicals attributable to toxoplasmosis infection. T. gondii infection also had a prominent influence on the association between OS biomarkers and immune-suppression status in seropositive donors