TOLL-like receptors polymorphism in pneumonia associated with influenza A(H1N1)/09

Introduction: Pneumonia is one of the most common infections with high mortality rates (especially, during the flu epidemics). Toll-like receptors are a class of cellular receptors that recognize the conservative structures of microorganisms and activate the cellular immune response. When Toll-like receptors are activated, an inflammatory signaling cascade is triggered.. Polymorphism of Toll-like receptor genes violates this mechanism, which leads to the risk of pneumonia. Today, this issue is not is not well understood. Aims and Objectives: The main purpose of the study was the analysis of the role of Toll-like receptors-4 polymorphism (TLR4 Asp299Gly, TLR4 Thr399Ile) and the risk of lethal outcome in pneumonia associated with influenza A(H1N1)/09. Methods: 100 patients with severe pneumonia were examined in 2019. The ethiology verification was performed using polymeraze chain reaction (100% positive result - RNA virus A(H1N1)/09). In all patients polymorphisms of the TLR4 (Asp299Gly and TLR4 Thr399Ile) was performed using polymeraze chain reaction. Results: The average age of the patients was 53 [48; 63] years, gender proportion: 56% male, 44% - female. From the whole group ARDS was confirmed in 32% pts. In 8 patients polymorphisms of the TLR4 was detected: 6 – both Asp299Gly and Thr399Ile, 2- only Asp299Gly. Of them 4 patients died, 4 survived. An odds ratio (OR) for lethal outcome in patients with TLR4 polymorphism (Asp299Gly and Thr399Ile) was 3,38 (CI 0,78; 14,69). Conclusion: Toll-like receptor-4 gene polymorphism was probably associated with poor outcome in severe pneumonia associated with influenza A(H1N1)/09. This problem demands further studying.