In the present study we analysed the content of final lipid peroxidation products reacting with thiobarbituric acid - TBARS, in erythrocytes and plasma, as well as the concentration of reduced glutathion (GSH) in the group of 57 children with systemic diseases of connective tissue (sdct). Children with juvenile chronic arthritis (JCA), systemic lupus erythematosus (SLE), Raynaud syndrome and mixed connective tissue disease (MCTD) demonstrated increased TBARS content in erythrocytes (p<0.001) in each case, while TBARS content was higher in plasma in case of JCA (p<0.001) and MCTD (p<0.03) when compared with the control group. GSH concentration in erythrocytes in children with JCA, SLA and MCTD was statistically significantly higher (p<0.02, p<0.001, p<0.002 respectively) when contrasted with both the control group and the group of children with Raynaud syndrome (p<0.02, p<0.001, p<0.001 respectively). The obtained results indicate that the process of lipid peroxidation play an important role in the development of systemic diseases of connective tissue (sdct) in children. These children did not show any disorders in antioxidation capacity.

Keywords: lipid peroxidation products, reduced glutathion, systemic diseases of connective tissue