Field evidence indicates differences in the rate and severity of COVID-19 infection among Afghans and Iranians, potentially influenced by individual genomic variances. Therefore, investigating the potential causes of these disparities holds significant clinical importance. This study aims to explore and compare variations in the genes encoding angiotensin-converting enzyme 1 (ACE1) and angiotensin-converting enzyme 2 (ACE2), along with total ACE activity levels in the blood of Afghans and Iranians with COVID-19, to assess any potential correlation with disease severity. In this case-control study, 124 Afghans and 124 Iranians with COVID-19 residing in Rafsanjan city, Iran, were examined. Blood samples were collected from all subjects, and serum was isolated for measuring total ACE activity using the kinetic method. DNA extraction was performed using the salting-out method, and gene polymorphisms of ACE1 and ACE2 were determined through polymerase chain reaction (PCR) and PCR-restriction fragment length polymorphism techniques. The DD genotype and D allele, as well as the GG genotype and G allele, were more prevalent among individuals with severe COVID-19 cases compared with those with mild symptoms, indicating an increased risk of severe infection. Although the Iranian group exhibited higher levels of these genetic components, along with longer hospital stays, intensive care unit admissions, and mortality rates than the Afghan group, the differences were not statistically significant. Furthermore, individuals with the DD genotype displayed double the total ACE activity levels compared with those with the II genotype, with the ID genotype falling in between. The presence of the DD genotype and D allele, as well as the GG genotype and G allele, likely serves as a significant risk factor for COVID-19 susceptibility, potentially heightening the risk of severe infection among Iranians compared with Afghans.
Keywords: ACE1; ACE2; Afghanistan; COVID-19; Iran; polymorphism.