Inflammatory Mechanism and Clinical Implication of Asthma in COVID-19

Asthma is a chronic inflammatory disease of the respiratory tract that has become a public health problem in various countries. Referring to the Global Initiative for Asthma, the prevalence of asthma continues to increase especially in children. Coronavirus Disease 2019 (COVID-19) is an infectious disease caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) that has declared a pandemic by the world health organization on March 2020. For many years, it has been known that people with asthma have a worse impact on respiratory viral infections. Asthma has been listed by the centers for disease control and prevention as one of the risk factors for COVID-19, although several studies have different results. SARS-CoV-2 utilizes angiotensin-converting enzyme 2 (ACE2) as its cellular receptor, and it has been known that the expression of the ACE2 receptor is reduced in asthma patients. This reduced expression could also be accounted from the therapy of asthma. This paper aims to discuss the pathophysiology of asthma and COVID-19 and the susceptibility of asthma patients in contracting COVID-19.