Total antioxidant capacity of plasma in asymptomatic carrier state ofNeisseria meningitidis

Abstract

SUMMARYReduction of the antioxidant capacity of plasma has been linked with the impairment of an effective immune response and so we hypothesized that the carriage rate ofNeisseria meningitidisin asymptomatic subjects might correlate with the levels of antioxidants in plasma. To this end we took pharyngeal swabs from 339 children in Marquesado Basic Health Zone, Granada, Spain and in addition determined the total antioxidant capacity (TAC) in plasma samples from these subjects. The overall prevalence ofN. meningitidiscarriage was 5·9% (mean age 7·1 years) with rates of 10·3% in children aged ⩽3 years, 3·9% between 4 and 7 years and 2·4% in older subjects. Plasma TAC for the ⩽3-year-olds was 0·13 for carriers and 1·10 for non-carrier controls (P=0·04), 0·13 for carriers aged 4–7 years (controls 0·63) and 0·28 for carriers aged >7 years (controls 0·52). We analysed the association between TAC in plasma (<0·37 – 2s.d.) and the carrier state ofN. meningitidis. In the carrier state, the odds ratio for this association (TAC in plasma <0·25) was 8·44 (95% CI 1·5–48·9). These findings may suggest a reduced immune response in the host favourable to nasopharyngeal persistence of meningococci.