INTERLEUKIN-4 AND SOLUBLE CD23 SERUM LEVELS IN ASTHMATIC ATOPIC CHILDREN

IL-4 is an essential mediator of IgE synthesis; it also upregulates th e expression of the low affinity receptor for IgE (CD23) and its relea se in soluble form (sCD23). The involvement of IL-4 and sCD23 on the I gE synthesis control has been observed in experimental studies. IL-4 a nd sCD23 serum levels in asthmatic atopic children were determined in order to investigate a possible correlation between these factors and IgE levels. IL-4, total sCD23 and Dermatophagoides pteronyssinus speci fic IgE were determined in the serum of 19 asthmatic atopic children ( aged 7 to 14) and in 13 age-matched controls. Since sCD23 may present an age-dependent variation, sCD23 and IL-4 serum levels were evaluated in 20 ''wheezy babies.'' IL-4 serum levels were significantly higher in patients as compared to controls, whereas there was no significant difference between them concerning sCD23 levels. sCD23 levels were, ho wever, significantly higher among ''wheezy babies'' as compared to ato pic and nonatopic children. There was no correlation between IL-4 and sCD23 serum levels, nor between any of these factors and IgE levels in all groups. In conclusion, the enhanced IL-4 levels suggest that atop ic patients have a preferential activation of Th2 subset. CD23 express ion is markedly influenced by age.