Pathogenetic Significance of Antimicrobial Peptides in the Implementation of Antibacterial Protection in Children with Cystic Fibrosis

• Main Authors: G.O. Lezhenko, O.Ye. Abaturov, O.Ye. Pashkova, L.I. Pantyushenko
• Format: Article
• Language: English
• Published: Publishing House Zaslavsky 2013-04-01
• Series: Zdorovʹe Rebenka
• Subjects: cystic fibrosis; defensins 1–3; nitric oxide; іNOS NTproBNP; Ps.aeruginosa
• Online Access: http://childshealth.zaslavsky.com.ua/article/view/88802

Objective: to investigate the factors increasing the colonization of respiratory system with Ps.аeruginosa in children with cystic fibrosis. Materials and methods. The study involved 37 children with cystic fibrosis at the age from 3 to 15 years. The control group consisted of 30 healthy children. The results of the bacteriological examination of sputum were evaluated. The plasma levels of α-defensins 1–3 (HNP 1–3), serum levels of C-reactive protein (CRP), metabolites of nitric oxide (NO), inducible NO-synthase (iNOS), NTproBNP were investigated. Results. According to the results of bacteriological examination of sputum pathogens was identified in 22 (59.4 %) patients. The dominant microorganisms were presented by Ps.aeruginosa in 14 (37.8 %) patients. Patients with cystic fibrosis have had 3.9 times increased levels of HNP 1–3 in plasma in comparison with control group (p < 0.05). The presence of Ps.aeruginosa led to the 6.8 times increase of HNP 1–3 in plasma of children with cystic fibrosis (p < 0.001). Simultaneously, the presence of Ps.aeruginosa resulted in an increase of CRP (p < 0.01). Contamination of the patients with cystic fibrosis by Ps.aeruginosa contributed to lack of NO and iNOS production. Colonization of the lower respiratory tract by Ps.aeruginosa associated with 1.7 times increased levels of NTproBNP in comparison with control group (p < 0.05). Conclusions: 1. Children with cystic fibrosis had been characterized by elevation of plasma level of α-defensins 1–3. Production of HNP 1–3 adaptively increased in response to the contamination of the respiratory tract by Ps.aeruginosa, but high concentration of α-defensins 1–3 depressed phagocytic activity of neutrophils. Under such conditions compensatory-adaptive response, that was intended at the overcoming of pathogenic contamination, take a turn of pathologic and was an additional factor of respiratory system affection. 2. In children with cystic fibrosis reduction of generation of nitric oxide regardless of the microbial status of respiratory system took place. Availability of Ps.аeruginosa in respiratory system microbiota assisted to the adequate course of the second phase of inflammation at the expense of absence of іNOS adequate activation. 3. Increased serum level of NTproBNP in children with cystic fibrosis, infected with Ps.aeruginosa, is a compensatory reaction in response to the activation of endothelin-1 synthesis and serves as additional factor of supporting of chronic inflammation and damage of the respiratory system.