Introduction: At the present time, the study of mechanisms of recognition of foreign agents, which is realized by means of Toll-like receptors (TLR) of the innate immune system, has become one of the main tasks of clinical immunology. The aim of our study was to investigate the prevalence of polymorphism of Toll-like receptor 4 (Asp299Gly, Gly299Gly) among children with chronic pyelonephritis (CP) and determine the association of this TLR4 polymorphism with phenotypic features of chronic pyelonephritis and level of interleukin-6 (IL-6).
Materials and methods: The clinical and laboratory examination of 60 children with chronic pyelonephritis during the stage of exacerbation, who were under inpatient treatment at the pediatric department of Children's Regional Clinical Hospital in Poltava, was performed. The group of healthy patients included 95 people, living in the Poltava region.
Results: Significantly higher frequency of the mutant allele 299Gly among children with CP was revealed. Significant correlation between the presence of 299Gly TLR4, association of U. urealyticum and M. hominis in lower sections of urinary tract and highest levels of IL-6 concentration was reflected. Sick children with polymorphous locus of TLR4 gene had higher risk of CP early manifestation and formation of its recurrent course with protracted urinary syndrome and unstable remission in comparison with the carriers of "wild" genotype.
Conclusions: Obtained results prove the important role of TLR4 in the realization of innate immune response in children with CP and allow considering the TLR4 polymorphism as an additional prognostic indicator in this category of patients.
Keywords: Toll-like receptors; innate immunity; interleukin-6; polymorphism; intracellular pathogens.