Apoptosis and immunophenotyping of peripheral blood lymphocytes in Iranian COVID-19 patients; clinical and laboratory characteristics.

A novel member of human coronavirus, named SARS-CoV-2, has been recently recognized in China and rapidly spread worldwide. Studies showed the decreasing of peripheral blood lymphocytes in a majority of patients. In this study, we have reported the clinical features, laboratory characteristics, the frequency of peripheral blood lymphocyte subpopulations and their apoptosis pattern in Iranian COVID-19 patients. Demographic and clinical data of 61 hospitalized confirmed cases with COVID-19 at Imam Khomeini Hospital were collected and analyzed. Peripheral blood mononuclear cells were isolated from all samples and the apoptosis pattern was evaluated using Annexin V/propidium iodide method. The frequency of lymphocyte subsets including T-CD4+ , T-CD8+ , NK, B cells, and monocytes was measured in all patients and 31 controls by flow cytometry. Our findings demonstrated that the percentage of lymphocytes, CD4+ , and CD8+ T cells were decreased in COVID-19 patients compared to control group. Regarding the clinical severity, the number of lymphocytes, CD4+ , CD8+ T cells, and NK cells were also decreased in severe cases when compared to mild cases. Finally, our data have also indicated the increasing in apoptosis of mononuclear cells from COVID-19 patients which was more remarkable in severe clinical cases. The frequency of immune cells is a useful indicator for prediction of severity and prognosis of COVID-19 patients. These results could help to explain the immunopathogenesis of SARS-CoV-2 and introducing of novel biomarkers, therapeutic strategies, and vaccine candidates. This article is protected by copyright. All rights reserved.