Association of IL-17F Gene Polymorphism and Its Serum Level with SARS-CoV-2 Infection.

Objective: Although multiple studies have addressed the clinical outcomes of coronavirus disease, little data exist regarding the defi- nition of immune and inflammatory profiles associated with this infection. Its clinical manifestations often worsen in association with hypercytokinemia (elevated interleukin 8 and interleukin 17). We conducted this research to elucidate the effect of interleukin 17 levels and interleukin 17F gene polymorphism on the severity and outcomes of coronavirus disease.

Material and methods: Ninety patients with confirmed coronavirus disease and 30 healthy controls were enrolled. Coronavirus disease cases were classified into nonsevere, severe, and critical according to the World Health Organization definition. Approximately 10 mL peripheral blood sample was collected from all patients and controls by venipuncture in-plane and ethylenediaminetetraacetic acid tube. Enzyme-linked immunosorbent assay kits were used for calculating serum interleukin 17 levels, whereas real-time polymerase chain reaction was used for genotyping using the 5'-nuclease allelic discrimination assay for single nucleotide polymorphisms genotyping.

Results: As regards interleukin 17 levels, there was a significant elevation of interleukin 17 in coronavirus disease cases compared to control healthy persons (P < .001). Moreover, serum interleukin 17 levels tended to be significantly higher with increased disease sever- ity (P = .004). Patients with critical diseases expressed a significant rise of interleukin 17 compared to severe (P = .03) and nonsevere cases (P = .02). We noted no significant difference between the critical, severe, and nonsevere cases regarding different interleukin 17F genotypes.

Conclusion: Coronavirus disease is associated with elevated levels of interleukin 17, which tended to be considerably higher with disease severity. However, different interleukin 17F genotypes do not affect either the predisposition or the severity of coronavirus disease.