Association of IFITM1 Promoter Methylation with Severity of SARS-CoV-2 Infection.

BACKGROUND

During viral infections such as SARS-CoV-2, epigenetic changes within the promoter region of the immune system genes would possibly occur and have an effect on the immune system response as well as disease outcome. We aimed to evaluate and compare the methylation level of the IFITM1 gene promoter in different stages of COVID-19 disease with a healthy control group.

METHODS

In this cross-sectional study, 75 COVID-19 patients (25 mild, 25 severe, and 25 critical in addition to 25 age- and gender-matched healthy volunteers) have been included. DNA was extracted from the peripheral white blood cells using a commercial DNA extraction kit. PCR was performed using two types of primers designed for the methylated and unmethylated forms of the IFITM1 gene promoter.

RESULTS

The mean age of the patient and healthy volunteer groups was 52.733 ± 13.780 and 49.120 ± 12.490, respectively. Out of a hundred participants, 52 were male. The results demonstrated that severe (p = 0.03, OR 6.729) and critical (p = 0.001, OR 11.156) patients were much more likely to show methylation of the IFITM1 gene in contrast with mild patients. Moreover, IFITM1 methylation was significantly higher in COVID-19 patients in comparison with the healthy volunteer group (p = 0.004, OR 3.17). Furthermore, IFITM1 methylation in male patients with critical status, (p = 0.01) was significantly higher than in male patients with mild status. In addition, IFITM1 methylation of male (p = 0.03) and female (p = 0.01) critical patients was considerably higher compared to males and females of volunteer group.

CONCLUSIONS

Increased methylation of the IFITM1 gene in the severe and critical stage of COVID-19 diseases may indicate the role of SARS-CoV-2 infection in increasing methylation of this antiviral gene. This might be involved in suppressing the immune system, promoting SARS-CoV-2 replication and disease outcome.