Evaluation of the interferons polymorphism for interferon-lambda and the specific antibodies to sSARS-COV-2 and cytomegalovirus in elderly people

Abstract

Currently, the world is facing a pandemic caused by the new coronavirus SARS-CoV-2, which causes the disease called "coronavirus disease - 2019" or COVID-19. It has been documented that the elderly are not only the most affected population, but also account for the highest number of deaths in COVID-19. In this sense, studies suggest that the higher rate of infection, severity, and lethality by SARS-CoV-2 in the elderly is associated with both the occurrence of immunosenescence, which consists an expressive decline in the immune responses, as well as the phenomenon named "inflammaging", which represents a chronic and systemic low-grade inflammatory state associated with aging. Taken together, these phenomena decrease the protection against pathogens, due to the lower efficiency of antibodies. In addition, the lack of response from the cytokine known as interferon (IFN) reduces the immune defense against infections, mainly viral infections. Based on this piece of information, the present study aims to investigate the levels of interferons type I, II, and III, the impact of polymorphism on IFN-lambda and also the specific antibodies response to SARS-CoV-2 in elderly individuals infected with cytomegalovirus (CMV). Blood samples will be collected from 120 elderly people of both sexes at different time-points of the disease (acute and cured phases). The volunteers, who presenting CMV infection, will be grouped according to the COVID-19 symptoms in: mild COVID-19 group (n = 30); moderate COVID-19 group (n = 30); severe COVID-19 group (n = 30) and non-COVID-19 and e CMV (n=30). The samples will be used to evaluate the serum concentration of specific immunoglobulins A, M, and G for SARS-CoV-2 and also specific-IgG for CMV, to determine the levels of interferon type I, II, and III, as well as the genotyping for the IFN-Lambda 3/4 gene polymorphism.