Nasal and oral swab Expressions of ACE2 and IL6 in Nigerian COVID-19 Patients with Varying Disease Severity

Abstract

Background: ACE2 receptor is crucial for SARS-CoV 2 entry into host cells, and pro-inflammatory cytokine storm causes mortality in COVID-19 patients. Blood levels of both ACE2 inhibitor and IL6 antagonists were considered for therapeutic management strategies during COVID-19. The study determined the molecular expressions of ACE2 and IL6 in nasal and oral swabs of COVID-19 Nigerian patients of different severities.

Materials and Method: Forty-five COVID-19 patients ( mild,   moderate   and   severe) were recruited from the Biorepository Clinical Virology Laboratory, University of Ibadan, Nigeria. Ten (10)   healthy individuals served as control.   Expression levels of ACE2 and IL6 were determined using q-RT-PCR. The threshold (Ct) values of the expressions were determined and fold changes (2^-ΔΔCT) values calculated. P < 0.05 was taken as significant.

Results: The mean swab Ct value of ACE2 expression was significantly reduced in combined COVID-19 cases compared with control, while mean swab IL6 Ct values were similar in cases and control. The mean swab ACE2 Ct values were significantly reduced in severe- and moderate-COVID-19 cases compared with control, while mean swab IL6 Ct value was significantly increased in mild COVID-19 cases compared with control. Sixty (60) %, 93% and 100% of mild, moderate and severe COVID-19 patients respectively had low swab ACE2 expression while 93%, 100% and 93% of mild, moderate and severe COVID-19 patients respectively had low swab IL-6 expression. Also, 67% and 50% of male and female COVID-19 patients respectively had low Ct values of swab IL6 expression. Thirty-three percent of females or ≥40yrs old COVID-19 patients had low Ct values of swab ACE2 expression while 33% and 100% of <40yrs and ≥40yrs old COVID-19 patients respectively had low Ct values of swab IL-6 expression.

Conclusion/Recommendations: ACE2 expression in swab might be used as an indicator of SARS-CoV 2 severity.