Introduction: Coronavirus disease 2019 (COVID-19) spreads all around the world and leads to several new infection cases and mortality. A better understanding of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pathogenesis could lead to more efficient therapeutic approaches.
Objectives: The current study aimed to investigate the Toll-like receptors expression profile in peripheral blood mononuclear cells in COVID-19 patients in Iran.
Patients and Methods: In this cross-sectional study, we evaluated 32 COVID-19 patients. At the admission time based on the disease severity patients were divided into two groups of severe and mild COVID-19. A group of 16 normal people was evaluated as the healthy control. Blood samples were collected before any treatment from patients at the admission time. Peripheral blood mononuclear cell isolation preformed on blood samples. RNA is extracted from human peripheral blood mononuclear cells and use for the cDNA synthesis. The expression level of TLR-3, 4, and 7 were evaluated by using semi-quantitative real-time polymerase chain reaction (PCR).
Results: The patient’s mean age was 57.12±3.08 years and 15 (47%) were male. The background disorders represent two patients in the severe group with respiratory disorders, four patients with cardiovascular disease, and seven patients with diabetes. The TLRs expression levels represent a higher expression of TLR-4 in COVID-19 in comparison with controls for TLR-4 (P=0.007), TLR-3 and 7 also represent up-regulation however there were no statistically significant differences in the relative fold changes (RFCs) between groups for all other evaluated TLRs (P>0.05).
Conclusion: The study highlights the importance of the TLR-4 in COVID-19 patients in expression level. Further studies for a clear conclusion about TLRs expression levels are recommended.