Evaluation of the Diagnostic Performance of Toll-Like Receptors 4 and 9 as Reliable Markers for Corona Virus Disease-19

Respiratory, multiorgan, and heart failure are the causes of mortality from COVID-19 so this pandemic has increased interest in the biochemical processes that explain the complex interactions between infectious pathogens and human hosts. The virus's entry activates the immune system, including various toll-like receptor (TLR) pathways that result in the secretion of proinflammatory cytokines. This study aims to find meaningful COVID-19 biomarkers outside of conventional biochemical examinations. Patients and Methods: This study registered 100 people (n = 100), including 75 COVID-19 patients receiving care at the El Sahel Teaching Hospital and 25 healthy controls. We used RT-PCR, computed tomography (CT) scans, and biochemical routine profile tests like d-dimer, c-reactive protein (CRP), ferritin, and lactate dehydrogenase (LDH) to confirm that the COVID-19 virus was real. We measured toll-like receptor-4 (TLR-4) and toll-like receptor-9 (TLR-9) using the sandwich enzyme-linked immunosorbent assay (sandwich ELISA) method. Results: The results showed that there were statically significant differences in WBC, HCT, neutrophil, lymphocyte, monocyte, HbA1C, FBS, PPBS, and also COVID-19 profile biochemical tests except LDH. In the cases of TLR-4 and TLR-9, a significant difference appeared among the studied groups. We observed a highly significant correlation in the case of TLR-9 with ferritin and CRP. This study used ROC curves to measure the diagnostic accuracy of COVID-19. This study allowed for the accurate diagnosis of COVID-19 patients, with an AUC of 0.87 in the case of TLR-4 and 0.94 in the case of TLR-9. The ROC curve determined the cutoff points, and we measured the sensitivity and specificity of both TLR4 and TLR9 to be 80% and 79% for TLR-4, and 92% and 100% for TLR-9. Conclusion and Summary: TLR-4 and TLR-9 are effective biomarkers to distinguish between healthy and those with COVID-19 with acceptable sensitivity and specificity.