ANALYSIS OF POLYMORPHISMS IN SELECTED GENES IN CHILDREN WITH ASTHMA AND ASSOCIATION OF THESE POLYMORPHISMS WITH ASTHMA PHENOTYPES AND RESPONSE TO THERAPY

Astma je najpogostejša kronična bolezen otrok. Gre za vnetje dihal neznane etiologije. Je kompleksna bolezen, katere nastanka ni mogoče pojasniti z enim samim mehanizmom ali genom, pomemben vpliv pa ima tudi okolje. V številnih študijah so z astmo povezovali že več kot 100 genov, prispevek vsakega izmed njih pa je verjetno majhen. Mnogi geni, ki bi lahko imeli pomemben vpliv v patogenezi astme še niso poznani oziroma si študije med sabo nasprotujejo o njihovi vlogi na nastanek in fenotip astme. Kandidatni geni se razlikujejo tudi med populacijami. Preverili smo, kakšno vlogo imajo nekateri izmed kandidatnih genov pri slovenskih otrocih z astmo. Večina študij je zajela astmatike kot celoto. Mi smo preučili povezave kandidatnih genov posebej za skupino atopijskih in neatopijskih astmatikov. V naši študiji smo tudi preverili kakšen vpliv imajo izbrani polimorfizmi na klinične parametre pri astmi in kako vplivajo na odziv na terapijo z glukokortikoidi pri slovenskih otrocih z astmo. Z orodji bioinformatike smo izbrali 9 polimorfizmov v 9 genih. Genotipizirali smo 108 otrok z astmo, od tega 28 z neatopijsko in 80 z atopijsko obliko astme ter 92 zdravih kontrol. Genotipizacijo smo izvedli s pomočjo verižne reakcije s polimerazo (PCR) in s pomočjo metode polimorfizma dolžin restrikcijskih fragmentov (RFLP). Ugotovili smo povezavo polimorfizmov na genih CCR5, IL13 z neatopijsko ter na genu RANTES z astmo nasploh pri slovenskih otrocih, pri polimorfizmih na 8 genih smo ugotovili vpliv na klinične parametre pri astmi. Naša študija je prva, ki je povezala gena IL12B in IL13 z deležem dušika v izdihanem zraku pri astmatikih. Prav tako smo prvi, ki smo ugotovili vpliv genov IL13 in ORMDL3 na protiastmatično terapijo z glukokortikoidi. Ti podatki lahko v bodoče pomembno prispevajo k razumevanju patogeneze astme, ugotovitve o povezavi polimorfizmov z odzivom na terapijo pa lahko vodijo do diagnostične in terapevtske obravnave, ki bo ukrojena po meri vsakega posameznega bolnika z astmo, ter zato veliko učinkovitejša, hitrejša in z manj stranskimi učinki.Asthma is the most common chronic disease in children. It is an inflammation of the respiratory tract of unknown etiology. It is a complex disease whose occurrence can not be explained by a single mechanism or gene, but the environment also has important impact. Numerous studies have associated asthma with more than 100 genes, but the contribution of each of them is probably very small. Many genes contributing to the asthma pathogenesis still need to be dicovered. In addition , many candidate genes initially associated with asthma and asthma phenotypes were not confirmed as asthma genes in the follow up independent studies in different populations In the most association studies candidate genes were compared between controls and all asthma patients in one group and only a few studies analysed asthma patients into separate groups according to the different asthma subphenotypes. The aim of our study was the association analysis of selected candidate genes in Slovenian children with asthma. We analysed candidate genes in all astmatics and also separately in the group of atopic asthmatics and the group of non-atopic asthmatics. In our study, we have analysed also corellation among polymorphisms in the selected candidate genes, clinical parameters and response to therapy with glucocorticoids in Slovenian children with asthma. We have selected nine polymorphisms in the nine different candate genes using bioinformatic tools. We have genotyped 108 children with asthma (28 of them has non-atopic and 80 atopic asthma) and 92 healty controls. We have performed genotyping by polymerase chain reaction (PCR) and by the restriction fragment length polymorphism (RFLP) analysis. We have found that polymorphisms in genes CCR5, IL13, and RANTES are significantly associated with asthma in Slovenian children. For polymorphisms in 8 genes we have found effects on clinical parameters in asthma. Our study was the first that associated IL12B and IL13 gene with a nitrogen in the exhaled air of asthmatic patients. We were also the first ones who associated IL13 and ORMDL3 genes with response to asthma therapy with glucocorticoids. Our results contribute to our understanding of the asthma pathogenesis of. Identification of polymorphisms associated with asthma phenotypes and response to therapy may lead custom tailored and better managment of asthma, patients