RESUMO
In spite of long-standing interest of researchers to problem of high susceptibility of frequently ill children to agents of respiratory diseases, so far no pathogenic mechanisms of this phenomenon were established. Therefore, selection of appropriate techniques of prevention of frequent respiratory diseases is complicated. Previously, the key role of cortisol and lipid-transferring system of blood in pathologic process was demonstrated. However, the assumption was expressed concerning heterogeneity of group of frequently ill children in content of cortisol - possibly conditioned by polymorphism of receptors to cortisol and as a sequence alteration of their quantity and sensitivity to this hormone. In turn, occurring imbalance between amount of cortisol and receptors is able to result in large specter of metabolic and immunological alterations. The purpose of this study was investigation of content of cortisol in blood, amount of its nuclear receptors in leukocytes and also lipid-transferring system of blood of frequently ill children examined in autumn in inter-morbid period. The statistical analysis of received results permits stating that group of frequently ill children is heterogeneous and is presented by two sub-groups with reliably differing by level of cortisol and ratio cortisol/ receptors to cortisol. This phenomenon cab be conditioned by polymorphism of genes coding nuclear receptors to cortisol, ATP- binding cassette transporter, lecithin cholesterol acyltransferase, scavenger-receptors. The step-by-step discriminant analysis with development of discriminant diagnostic model detected cortisol, cholesterol of high density lipoproteins and cholesterol of low density lipoproteins as valuable factors being active participants of development ofphenomenon of frequently ill children.