The Effect of Angiotensin-Converting Enzyme Insertion/Deletion Polymorphism on the Severity and Death Rate of COVID-19 in Iranian Patients

The study was designed to assess the association of ACE I/D polymorphism with the severity and prognosis of COVID-19 in the Iranian population. Hence, 186 adult patients were categorized into three clinical groups based on the severity of COVID-19: 1) Outpatients or mildly symptomatic patients as control (n = 71); 2) Hospitalized patients or severe symptomatic cases (n = 53); 3) Inpatients led to ICU/death or critically ill patients needed mechanical ventilation (n = 62). The possible association of ACE I/D polymorphism with the risk of comorbidities and serum level of C-reactive protein was evaluated in two severe cases. The results showed that the frequency of D and I alleles are 69.35% and 30.65%, respectively, in the total population. The analysis of allelic frequencies via Fisher's exact test confirmed significantly higher frequency of D allele in both severe groups than that in the mild one, 78.31% in Hospitalized patients (OR = 2.56; 95% CI 1.46 to 4.46; p-value = 0.0011) and 74.19% in Inpatients led to ICU/death (OR = 2.04; 95% CI = 1.22 to 3.43; p-value = 0.0094) compared to 58.45% in Outpatients. The results of genotype proportions displayed an association between COVID-19 severity and DD genotype. Overall, our findings in Iranian patients supported the undeniable role of the DD genotype in the intensity of the disease, comparable to other populations. Furthermore, there is no definite evidence regarding the protective effect of the I allele in our inquiry.