The D allele of angiotensin-converting enzyme gene insertion/deletion polymorphism is associated with the lung involvement in COVID-19

Objectives In COVID-19, severe lung involvement develops in some patients. The reason for the predisposition to lung involvement in some patients is not yet fully understood. Genetic variabilities in angiotensin-converting enzyme (ACE) may explain why some patients are more susceptible to lung injury. Thus, the ACE gene insertion/deletion (I/D) polymorphism was investigated in COVID-19 patients with and without lung involvement. Methods The study involved 216 patients who were divided into two groups as with and without pulmonary involvement according to their thoracic computed tomography (CT) scan findings. The ACE I/D gene polymorphism was determined. Results Carriers of the DD genotype had a 4.05-fold (OR=4.05, 95% CI: 1.66-9.86, p=0.001) greater incidence of pulmonary involvement. The probability of lung involvement was 2.41-fold higher in D allele carriers (OR=2.41, 95% CI: 1.62-3.60, p=0.000). The I allele was found to be protective and diminished the occurrence of lung involvement (OR=0.41, 95% CI: 0.28-0.62, p=0.000). Conclusions In COVID-19 patients, the I allele may lower the risk of lung injury and provide a protective effect. Conversely, the D allele may raise the risk of lung injury and lead to poor outcomes.