Comparative study of pro-Inflammatory and anti-Inflammatory cytokines for understanding the severity in patients infected with SARS-CoV-2 and other Respiratory viruses

A series of hyper immune responses as combined reaction of innate and adaptive immunity may lead to cytokine storm prolonging sickness and causing severities among patients of respiratory infection in general and attack COVID-19 patients in particular. We measured the levels of inflammatory cytokines viz. TNF-alpha, Interleukin-6 and Interferon-gamma. The initiation of immune system against viral infection involves role of cytokines. In Severe Acute Respiratory Distress Syndrome-Coronavirus-2 (SARS-CoV-2) infection, high levels of cytokine were observed which led to severity in immune-compromised patients, elderly and even mildly infected patients. High levels of cytokines have not only been observed in SARS-CoV-2 but are also prevalent in other human coronavirus infections. There are other respiratory diseases occurring in the form of epidemics and outbreaks in all parts of the world, yet understanding of the fact that when system gets infected by more than one respiratory virus, the cytokine expression observed has not been looked upon. This is irrespective of the fact that antibodies may already be present against respiratory diseases within the system over the course of time. We hereby hypothesise that if cytokine storm due to such condition may lead to activation of Th1/Th2 response, develop severity/complications and ultimately may lead to lung damage. In this study, we measured the cytokine response profiles (TNF-alpha, interleukin-6 and IFN-gamma) in patients with respiratory viral infections and we observed that TNF-α is the main factor contributing to cytokine storm and that hyper innate immune response is brought by mucosal immunity during infection by SARS-CoV-2.