In our study we sought to determine the physiologic range of cytokine concentrations in plasma and urine in healthy children scheduled for different types of operations. First group was constituted of children without prior history of repeated infections, scheduled for eye surgery for non-inflammatory disease. The second group was constituted of children scheduled for elective adenotomy because of repeated upper respiratory tract infections. Demographic and hematologic data revealed no differences between groups. High concentrations of sIL-2R in urine (130.3 ± 25.9 nmol/l) and zero concentrations of IL-6 in both plasma and urine (ng/l) were found in children scheduled for eye surgery. These represent healthy population regarding their medical history, with past eye corrective surgical procedures only. Low concentrations of sIL-2R in plasma (32.7 ± 3.9) and urine (47.0 ± 14.3) and, on the other hand, detectable concentrations of IL-6 in serum (2.3 ± 2.3) and urine (2.9 ± 1.8) were found in children with repeated chronic infections of upper respiratory tract in their medical history who were scheduled for adenotomy. The results of this study imply that O in spite of sIL-2R O the sole presence of IL-6 in plasma and urine is a sign of chronic stimulation of immune system in past medical history and is not influenced by transient stimuli, e.g. psychic stress.

        Key words: children O cytokines O IL-6 O sIL-2R O repeated infections