Роль генетически детерминированного дефицита лектинового пути активации комплемента при хронической инфекции Helicobacter pylori у детей

Abstract

Aim. To study the association of six polymorphic regions of MBL2 (rs11003125, rs7096206, rs7095891, rs1800450, rs1800451, rs5030737), two regions of FCN2 (rs7851696, rs17549193) and one region of MASP2 (rs72550870) with Helicobacter pylori infection and the severity of neutrophilic inflammation in gastric mucosa among children with recurrent abdominal pain. Design. Genetic association study of single nucleotide polymorphisms, case — control type. Materials and methods. 96 adolescents aged 12–17 years with recurrent abdominal pain were examined. Medical history, general clinical methods and fibrogastroscopy with a biopsy of the gastric mucosa were included in the medical testing. Biopsy samples were recorded and processed to assess the neutrophil infiltration and the presence of H. pylori. The results were interpreted according to the Sydney System of Gastritis Classification. Genotyping of allelic gene variants was carried out using real-time polymerase chain reaction (MBL2, MASP2), as well as the restriction analysis of amplification products of specific genome regions (MBL2, FCN2). Results. A high rate of H. pylori colonization was associated with a high frequency of the L allele of the rs11003125 gene polymorphism of the MBL2 gene and with a decrease in the proportion of high MBL — expressing genotypes. Carriage of the Q allele of the rs7095891 gene polymorphism of the MBL2 gene was associated with less pronounced neutrophilic infiltration, and a high frequency of the T allele of the rs7851696 gene polymorphism of the FCN2 gene was associated with severe neutrophilic inflammation in gastric mucosa. No differences in the distribution of MASP2 genotypes were found. Conclusion. The results obtained suggest that genetic defects in the production of MBL and ficolin-2 may cause chronic helicobacteriosis in children and more severe inflammation of gastric mucosa. Further study of these proteins seems to be promising for new approaches to the treatment and prevention of H. pylori complications in children to be identified. Keywords: Helicobacter pylori, mannose-binding lectin, ficolin, MASP, gene polymorphism.