The effect of endogenous antimicrobial peptides (HNPs1-3 and LL-37) on the course of duodenal ulcer in children

Introduction. Duodenal ulcer in children is characterized by a significant prevalence, frequent development of serious complications and the need for large financial allocations for the implementation of treatment programs. Antimicrobial peptides have an immunomodulatory function and can be used as markers of the severity of the inflammatory process.Aim. To investigate the concentration of HNPs 1-3 and LL-37 in children with duodenal ulcer.Methods. A study of 47 children with duodenal ulcer, aged 7–18 years, was conducted with the determination of the CagA HR antigen in feces by enzyme-linked immunosorbent assay, the levels of HNPs 1-3 and LL-37 in blood plasma by enzyme-linked immunosorbent assay on the "PrisMatic" IN013 model 4301 analyzer test systems "MyBioSource, Inc.", USA. All children underwent a complex clinical and instrumental laboratory examination (topographic intragastric pH-metry, endoscopic examination with targeted biopsy for morphological examination and determination of HP). Results. 76.6% of people with DU were infected with HP. 80% had a toxigenic CagA strain of HP. In the vast majority of children with DU, small ulcerative defects were diagnosed. II and III degrees of inflammatory activity occurred with almost the same frequency (44.6% and 34% of people), while I degree occurred only in 21.3% of cases. The average level of HNP1-3 in children with DU was 46.56 ± 8.52 ng/ml, LL-37 - 269.9 ± 26.53 ng/ml. Direct probable connections between the levels of HNP1-3 and LL-37 and the severity of the course and the activity of the inflammatory process were established.Conclusion. Elevated levels of LL-37 and HNPs 1-3 were found in the blood plasma of children with duodenal ulcers associated with CagA strains of Helicobacter pylori. Significantly higher levels of LL-37 and HNPs 1-3 were registered with a severe course of the disease and an active inflammatory process, which indicates a direct influence of antimicrobial peptides on the course of the pathological process.