Povezanost neurorazvojnih poremećaja sa varijantama gena za laktazu, humani antigen leukocita i receptor vitamina D, kao i sa prisustvom opioidnih peptida u urinu i crevnom disbiozom

Abstract

Nutritivne deficijencije, gastrointestinalne smetnje i intolerancija na hranu često su opisivane kod dece sa neurorazvojnim poremećajima (eng. neurodevelopmental disorder, NDD). Pretpostavljeno je da opioidni molekuli, poreklom od proteina kazeina i glutena mogu dovesti do nastanka nekih neuropsihijatrijskih simptoma. S obzirom da su do sada u literaturi povišene koncetracije ovih peptida u urinu opisivane kod pacijenata sa autizmom, ali ne i drugim formama NDD, prvi cilj ove teze bio je proveriti da li kod NDD pacijenata postoji povišen nivo kazo- i gluten egzorfina u urinu metodom tečne hromatografije visokih performansi. Kako je glavni preduslov da navedeni peptidi dospeju u cirkulaciju povećana propustljivost crevnog epitela, istraživanje je dalje bilo usmereno na ispitivanje učestalosti genetičkih varijanti asociranih sa celijačnom bolešću (HLADQ) i laktoznom intolerancijom (LCT-13910C>T) metodama baziranim na PCR analizi i ispitivanju promena u sastavu crevne mikrobiote metodom gel elektroforeze u denaturišućem gradijentu. Kod većine pacijenata sa NDD detektovan je nedostatak vitamina D, zbog čega je metodama PCR analize ispitivana učestalost genetičke varijante VDR FokI, koja je u literaturi dovođena u vezu sa autizmom. Rezultati istraživanja pokazali su povećanu koncentraciju analiziranih peptida u urinu NDD pacijenata koja nije bila asocirana sa genetičkim markerima za celijačnu bolest i laktoznu intoleranciju. Značajno viša učestalost genotipa VDR FokI CC ("FF") je pokazana kod pacijenata sa dečijim autizmom u odnosu na zdrave kontrole, ali i ostale grupe NDD pacijenata. U grupi pacijenata uočena je manja zastupljenost i smanjen diverzitet bakterija koje čine normalnu crevnu mikrobiotu, kao i veća zastupljenost potencijalno patogenih bakterija.

Nutritional deficiencies, gastrointestinal disturbances, and food intolerance are frequently observed in children with neurodevelopmental disorders (NDD). It was hypothesized that opioid molecules, originally derived from the protein of casein and gluten, may induce some of the neuropsychiatric symptoms. Since the elevated levels of these peptides in the urine have so far been described in medical literature in patients with autism, but not in other forms of NDD, the first goal of this thesis was to check whether the NDD patients have elevated levels of casein- and gluten exorphins in the urine using the method of High performance liquid chromatography. Since increased intestinal permeability is the main precondition for the presence of these peptides in circulation, the research was further directed to examine the frequency of genetic variants associated with celiac disease (HLA-DQ) and lactose intolerance (LCT-13910C) methods based on PCR analysis and to examine changes in the composition of gut microbiota. Given that the vitamin D deficiency was detected in most of the NDD patients, the frequency of the genetic variant VDR FokI, which has been linked to autism in the medical literature, was examined by methods based on PCR analysis. Results indicated that increased concentrations of analized peptides observed in NDD patients were not associated with genetic predictors for celiac disease or lactose intolerance. A significantly higher incidence of the Fokl CC (FF) genotype in patients with childhood autism was noted compared to healthy control and other groups of NDD patients. Within the patients group a lower incidence and diversity of common commensal bacteria was noted, as well as the higher incidence of potentially harmful bacteria.