The effect of the CD4+ T cell subset and anti-tubercular therapy on SARS-CoV-2 clearance in patients with COVID-19 and tuberculosis co-infection

Introduction. The coronavirus disease (COVID-19) pandemic has prompted the study of problems of comorbidities, including widespread and highly pathogenic comorbid infectious diseases. Tuberculosis continues to be major infectious disease in terms of social life and epidemiology that can have a negative impact on the outcomes of patients with COVID-19 and other infectious diseases, including because of the association of pathogenetic mechanisms of these infectious diseases is still unclear. The study of risk factors for adverse outcomes of tuberculosis and COVID-19 co-infection will improve managing these diseases. Aim. To evaluate the impact of changes in immunocompetent cell subsets and specific treatment regimens on SARS-CoV-2 clearance in the respiratory tract of patients with COVID-19 and tuberculosis co-infection. Materials and methods. In a retrospective cohort clinical study we have analyzed the clinical characteristics and duration of elimination of coronavirus (SARS-CoV-2) from the respiratory tract of 76 hospitalized patients with COVID-19 and active tuberculosis. The first group included 37 patients with COVID-19 and active pulmonary or extrapulmonary tuberculosis without signs of lymphogenous or hematogenous spread of Mycobacterium tuberculosis infection (TB P/EP). The second group included 39 patients with COVID-19 and disseminated tuberculosis (DTB). Results. When constructing multiple regression models, the CD4+ count less than 80 cells/µl was the strongest determinant of delayed elimination of SARS-CoV-2 from the respiratory tract with a regression coefficient (β ± m) of 21.762 ± 6.250 (p = 0.002) and 10.853 ± 4.220 (p = 0.015) in the first and second groups, respectively. In combination with the duration of anti-tubercular therapy, antiretroviral therapy, anemia, and platelet count, these factors made it possible to predict a 68.1% variances in the duration of elimination of SARS-CoV-2 from the respiratory tract of patients with TB P/EP, and a 42.7% variances of this indicator in patient with COVID-19 and DTB co-infection. Conclusion. A decrease in the CD4+ count less than 80 cells/µl, the duration of the intensive phase of anti-tubercular therapy, antiretroviral therapy, anemia, peripheral blood platelet count have a comprehensive impact on prolongation of SARS-CoV-2 elimination from the respiratory tract of patients with COVID-19 and tuberculosis co-infection.