Immunological profile and diagnostic indices of inflammation as prognostic markers of clinical outcome in patients with SARS-CoV2 infection

ABSTRACT

Background The clinical course of pneumonia caused by SARS-CoV-2 is quite peculiar and is characterized by a rapid deterioration of the clinical condition of patients. The aim of this study is to characterize immunological dysfunctions in COVID-19 patients and correlate them with markers of hyperactivation of the inflammatory response, in an attempt to find threshold values indicative of patient outcome. Methods A total of 100 patients were recruited. All patients had a positive PCR test for SARS-COV-2 from nasopharyngeal sample. Patients were grouped into those who did not require mechanical ventilation (n=72) and those who required mechanical ventilation (n=28). Blood samples were collected and analyzed at the point of admission in all patients. Patient immune phenotyping was performed in whole blood samples of patients by flow cytometric analysis. The flow cytometric analysis was performed in an Aquios cytometer (Aquios -Beckman Coulter CA, USA). Antibodies used for cell staining are TETRA-1 Panel (CD45, CD4, CD8, CD3). Data were analyzed using flow cytometric analysis software. Data from the routine biochemical assessment performed in the first 24 hrs after admission to infectious diseases unit will be collected. Results Both the percentage and the absolute number of neutrophils were higher in patients needing ICU care than non-ICU patients, whereas absolute lymphocyte count, and especially the percentage of lymphocytes, presented a deep decline in critical patients. There was no difference between the two groups of patients for CD4 Tlymphocytes, neither in percentage of lymphocyte nor in absolute number, however for CD8 T-cells the differences were significant for both parameters which were in decline in ICU patients. There was a firm correlation between the highest values of inflammation indicators with the decrease in percentage of CD8 T-lymphocytes. This effect was not seen with CD4 cells. Conclusion Our results describe the immune response of severe COVID-19 patients and highlight the value of a novel ratio of CD4/CD8 as a putative marker of poor prognosis. Nevertheless, further research is warranted in order to fully comprehend the transition of the different stages of COVID-19 progression in the context of successful combat of this novel disease.