The role of Toll-like receptor 4 Asp299Gly genetic polymorphism in rehabilitation of patients with post-COVID syndrome

Abstract

Introduction. The multivariability of the clinical course of post-covid syndrome (PCS) is associated with genetic heterogeneity of the population, which leads to a high interest in the study of genotypes. Aim. To evaluate the role of Toll-like receptor 4 (TLR4 (Asp229Gly) polymorphism in the formation of PCS and rehabilitation potential. Materials and methods. The study included 92 patients diagnosed with PCS between the ages of 21 and 75. All patients received a comprehensive clinical, laboratory, functional examination and quality of life assessment at admission and discharge. Deoxyribonucleic acid isolation and allele-specific polymerase chain reaction were performed from whole blood using «Lytech» kits (Russia) according to the manufacturer's instructions. Formation of groups for statistical processing was carried out in accordance with the results of genetic analysis. Patients received comprehensive rehabilitation, including: climatotherapy, exercise therapy, massage, aromatherapy, respiratory therapy. Performance was assessed based on the dynamics of the studied indicators. Results and discussion. Of the 92 patients included in the study, 22 (23.9 %) were AA homozygotes, 33 (35.8 %) were GG, and 37 (40.3 %) were AG heterozygotes. By age, the groups were comparable. The gender ratio was predominantly female in all groups. According to the initial characteristics, the condition of patients with more pronounced clinical symptoms was in the group of patients with the AG genotype. All groups showed varying degrees of positive dynamics. The dependence of the severity of PCS and the effectiveness of rehabilitation on genetic predisposition was established. Different severity of initial clinical symptoms and deviations of functional parameters were revealed. Significant differences were found when assessing the effectiveness of rehabilitation. Positive dynamics was observed in all groups, but most successfully in the AG group. This confirms the role of TLR4 in the immunological response to SARS-CoV-2 and its genetic polymorphism in a wide range of manifestations of both acute COVID-19 and PCS. Conclusions. The effectiveness of rehabilitation in patients with PCS is interrelated with the genetic heterogeneity of TLR4. The heterozygous variant of the AG genotype forms more pronounced clinical manifestations of PCS, but also a higher rehabilitation potential, which contributes to the successful completion of rehabilitation. The minor allele TLR4 (Asp299Gly) G is associated with a worsening of the course of PCS. Patients with the homozygous GG genotype need a longer course of rehabilitation.

Keywords

• toll-like receptor 4 (tlr4)
• genetic polymorphism
• post-covid syndrome
• rehabilitation