Correlation between serum Angiotensin II level and severity of COVID-19 disease

Coronavirus disease 2019 (COVID-19) is a global pandemic caused by novel coronavirus SARS-CoV-2. Angiotensin-converting enzyme 2 (ACE2) is a key player in the pathophysiology of COVID-19, as it facilitates the cellular viral entry, which in turn causes upregulation of Angiotensin II (Ang II) which correlates with the severity of infection and inflammation. Assessing the serum levels of Ang-II among COVID-19 patients, and correlate it with disease severity. Eighty patients of COVID- 19 and 80 healthy subjects were enrolled in this cross sectional study. COVID-19 patients was divided to 4 groups; mild, moderate, severe, and critical groups, according to WHO classification of severity of the disease .Beside clinical, laboratory (CBC, CRP, D-dimer, liver and kidney function tests) and imaging assessment, Ang II level was measured using ELISA kits. Levels of Ang-II are significantly higher in COVID-19 patients (281.82 ± 114.54 pg/dl) compared to control (72.53 ± 21.86 pg/dl), with a p-value < 0.001. Significant higher levels were detected in severe and critical cases, which were 347.65 ± 37.70 and 436.06 ± 53.00, respectively, as compared to mild and moderate cases, which were 132.16 ± 27.98 and 216.44 ± 49.47 pg/dl, respectively. An ROC curve for detection of the cutoff value of Ang II level was 115.5 pg/dl with an AUC of 0.990. Moreover, a cutoff value of Ang II for determining the severe and critical cases was 300.05 pg/dl with an AUC of 1.000. Ang-II may be a potential biomarker that could aid in determining the severity of cases aiming at the development of therapeutic strategies to mitigate disease severity.