Associations of Toll-like Receptor Gene Polymorphisms with NETosis Activity as Prognostic Criteria for the Severity of Pneumonia

The aim of the study was to determine the molecular genetic prognostic criteria for the severity of the course pneumonia based on the analysis of the association of genetic polymorphism in toll-like receptors with the severity of NETosis. MATERIALS AND METHODS: The study included 38 patients with the main diagnosis of community-acquired pneumonia with a severe course. All the patients underwent standard clinical laboratory examinations, computed tomography of the thoracic organs, microbiological examination of blood and tracheobronchial aspirate. The level of neutrophilic extracellular traps (NETs) in blood smears was determined on the 1(st)–2(nd) and 5(th)–7(th) days of hospitalization. Genotyping of rs5743551 (TLR1), rs5743708 (TLR2), and rs4986790 (TLR4) polymorphic loci was performed by pyrosequencing. RESULTS: The level of NETs on the 1(st) day of admission was statistically significantly lower in heterozygous and homozygous carriers of rs4986790 (TLR4) polymorphism (AG and GG genotypes) compared with patients with the wild-type genotype (AA genotype) (p<0.05). When comparing the number of NETs with genotypes for rs5743708 (TLR2) and rs5743551 (TLR1) polymorphisms, no statistically significant correlation was found (p>0.05). The study of the NET level in dynamics demonstrated a decrease in the NETosis activity of neutrophils during the first week of hospitalization (p<0.05). The presence of the G allele in the patient’s genotype for rs5743551 (TLR1) polymorphism increases the risk of a poor outcome of the disease (p<0.0001) (OR=20.3; 95% CI (4.3–135.0)). CONCLUSION: The obtained data suggest that level of NETs is a marker of the activity of neutrophils which are closely related to the studied genetic polymorphisms, and affects the prognosis of the pneumonia outcome.