Protein carbonyl groups' content as a useful clinical marker of antioxidant barrier impairment in plasma of children with juvenile chronic arthritis.

The purpose of our study was to find out the intensity of free radical reactions in pediatric patients with different forms of juvenile chronic arthritis (JCA) on the basis of carbonyl groups' content in plasma proteins, evaluated with the use of Levine's method. We examined a population of 52 children with diagnosed JCA of different types and activities in the study. The carbonyl groups' content in plasma proteins of ill children was significantly higher than in healthy group (1.36 +/- 0.68 vs. 0.807 +/- 0.16 nmol/mg of protein). The carbonyls increased parallell with the activity of the disease; their content was significantly higher in children with high-disease activity than in children with medium- or low-disease activity. Moreover, children with oligoarthritis had carbonyls level 1.09 +/- 0.59 nmol/mg of protein, vs. 1.62 +/- 0.82 in children with systemic type of JCA. The values of carbonyls in children with polyarthritis were and 1.36 +/- 0.50 nmol/mg of protein. Correlation between the carbonyl groups content and the activity or the type of JCA may allow use of carbonyls as a clinical marker of antioxidant barrier impairment in this group of patients. This aspect of the disease may undergo pharmacologic modification in future.