Flow Cytometry Analysis of CD4⁺ and CD8⁺ T Lymphocytes in COVID- 19 Patients

The clinical presentation of COVID-19 varies greatly from case to another, with host characteristics playing a pivotal role. The immune system is a pivotal function in establishing the course of SARS-COV-2 infection. Severe instances of COVID-19 and the resulting death are caused less by the virus itself than by the destructive unrestrained immune response. Among the host determinants for poor disease prognosis is probably genetic vulnerability to dysregulated immune response. The objective of this work is to examine some of the host genetic variables that are being studied in relation to the severity of COVID-19. The complex relationship between autoimmunity and the pathophysiology of COVID-19 was examined. Patients with COVID-19 were recruited from AL-Dewaniyah Teaching Hospital and AL-Hussain Teaching Hospital in Karbala city. All patients had been diagnosed with the virus using real-time polymerase chain reaction. A total of 70 blood samples (35 from the mild group, 35 from the severe group, and 35 from the controlled group) were obtained in EDTA tubes. Orderly to investigate the correlation between the progression of disease and variations in specific regions of host immunoassays had been used by flow cytometry. The results of the flow cytometry were reported as the average percentage of positive cells for CD4 and CD8 immunological markers. Cases with COVID-19 had a substantially lower mean CD4 concentration than the healthy patients. Furthermore, the mean concentration of CD8 was significantly lower in cases with COVID-19 than in healthy. In addition, there is significant (P 0.001) decline in both CD4 and CD8 mean levels between patients with severe and mild COVID-19.