Investigating the correlation between the frequency of single nucleotide polymorphisms in the IFNAR2 gene with the severity of the Covid-19 disease

Understanding the complex processes of the immune system in dealing with the covid-19 infection, which is probably related to polymorphisms in cytokine and chemokine genes, can explain the pro-inflammatory condition of patients. Accordingly, in the present study, the correlation between the frequency of single nucleotide polymorphisms in the pro-inflammatory IFNAR2 gene and the severity of the disease of COVID-19 was investigated.

This research was reviewed by the ethics committee of the Pasteur Institute of Iran and was approved by this committee with the ethics code IR.PII.REC.1400.042. and continued from December 2021 to November 2022. This study was conducted on 954 patients with COVID-19, who were divided into two groups: those who recovered and those who died. COVID-19 infection in all 954 volunteers has been confirmed through rtReal Time-PCR of oropharyngeal or nasopharyngeal swabs.After taking blood samples from patients and extracting DNA, IFNAR2 gene was amplified using specific primers. Then RFPL method and Cac8I restriction enzyme were used to investigate rs2236757 polymorphisms in IFNAR2 gene. Genotype of people was determined according to the pattern of formed bands. The results were statistically analyzed using SPSS software.

Calculation of genotypic frequency of rs2236757 polymorphism in IFNAR2 gene showed that in general 21% of cases had AA genotype, 47% GA genotype and 32% GG genotype. The allelic frequency of this polymorphism showed that 56% of cases had G allele and 44% had A allele. In investigating the correlation of rs2236757 polymorphism in IFNAR2 gene with the severity of the disease of Covid-19, the OR value for the GG genotype was equal to 1, which indicates the absence of the role of this polymorphism in the severity of the disease. On the other hand, A allele was significantly more in recovered people than in deceased people, and the value of OR<1 also confirmed this issue.

The results showed that rs2236757 in the IFNAR2 gene is related to the reduction of disease severity, which indicates the important role of genes related to inflammatory responses, as well as the role of genetic variants of these genes in the severity of COVID-19.