Evaluation Of Lymphocyte Subsets In Hospitalized Covid-19 Patients In Pune

Abstract

Background: The protective role of CD4+ and CD8+ T cells was hypothesized based on research on SARS and MERS patients, and recent data confirms their participation in SARS-CoV-2 infection. Lymphopenia, like other coronaviruses and viral infections, is a characteristic indication in people with advanced COVID-19 disease. The study was performed on hospitalized COVID-19 patients a tertiary care center Pune, (India), to analyze peripheral white blood cell changes in lymphocytes.

Methodology: The PBMCs were isolated from enrolled study participants and flow cytometry analysis was done to assess changes in peripheral white blood cells. The lymphocyte subsets including CD4+T cells, CD8+T cells, B cells, NK cytotoxic cells and NK regulatory cells were evaluated in COVID-19 patients with different disease category and compared to healthy controls.

Results: The immunophenotypic characterization of peripheral blood cell subset was done for 50 COVID-19 patients and 14 healthy controls. These data were evaluated based on the disease severity. A total of 50 COVID-19 patients were classified as mild (n = 18), moderate (n = 17), or severe (n = 15) cases. In patients with severe SARS-Cov-2 infection, lymphocyte counts, CD8+ T cell counts were significantly reduced while an increased ratio of CD4+/CD8+ T cells, cytotoxic NK cells and B cells was observed.

Conclusion: Our study showed that, SARS-CoV-2 infection was associated with changes in peripheral lymphocyte expression of certain subtypes. This observation can be used to predict better clinical outcomes for patients with aggressive treatment protocols for severe patients.