Study of Interferon-Induced Transmembrane Protein 3 Gene Polymorphism and Serum Interferon-λ3 Level in COVID-19.

BACKGROUND

Variations in individuals' susceptibility to coronavirus disease 2019 may be linked to the presence of genetic polymorphisms. The interferon-induced transmembrane 3 (IFITM3) has a powerful protective function by blocking viral entry into the host cell. Similarly, Interferon Lambda 3 (IFNL3) binds to its receptors and induces a variety of interferon-stimulated genes (ISGs) that inhibit viral replication. Our study aimed to investigate the potential association of IFITM3 gene polymorphism (rs12252) as well as serum IFNL3 level with COVID-19 infection, severity, and mortality.

METHOD: This case-control study was held during the period from July 2021 to October 2022 in Mansoura University hospitals in Egypt. We included 100 healthy controls and 154 COVID-19 patients. TaqMan real-time polymerase chain reaction was used for allelic discrimination in the genotyping of rs12252 of the IFITM3 gene. Serum IFNL-3 was assayed using the ELISA technique.

RESULTS

The genotype and allele frequency distributions of the rs12252 showed that the frequency of the G allele and AG/GG genotypes was significantly higher in patients than in controls, with no significant association with either disease severity or outcome. Serum IFNL3 level is significantly higher among patients, with no statistically significant difference between mild and severe cases and no significant association with the outcome of COVID-19.

CONCLUSION

We found that the AG genotype and G allele of IFITM3 rs12252 are associated with COVID-19 infection in the Egyptian population but not with severity or outcome. Additionally, serum IFNL3 level is significantly associated with COVID-19 susceptibility but not with severity. It is associated with tachypnea and end-organ failure in severe cases. So, they are independent predictors only for developing COVID-19 infection, but not for developing severe infection.