Serum contents of 7 cytokines (IL-1, IL-1beta, IL-6, IL-8, TNF-alpha, INF-gamma, INF-alpha) were examined in 87 children aged 14-17 years according to presence of antibodies against Helicobacter pylori and cytotoxic CagA protein. There was a lack of difference in cytokine levels between infected and non-infected children. Thus H. pylori infection in children in contrast to adults does not cause changes in systemic cytokine secretion.