Potential predictors of COVID-19 disease infection and severity in Egypt.

This study aimed to detect the changes in certain immunological parameters and miRNAs in COVID-19 cases with various degrees of disease severity and compare these changes in cases to healthy controls. This study was conducted on 45 COVID-19 patients and 45 healthy controls. The flow cytometry was conducted to study the number of CD4 + and CD8 + T cells and evaluate the level of the PD-1 marker on their surfaces for all study participants. The determination of IL-1β and IL-6 in serum for all study subjects was done by ELISA test. Relative gene expression quantitation of miR-146a and miR-133a was performed by reverse transcriptase real-time PCR (RT-PCR). The numbers of CD4 + and CD8 + T cells were dramatically reduced in COVID-19 patients, especially in severe to critical patients, with an increase in the CD4 + :CD8 + ratio. T cells from COVID-19 patients had significantly higher levels of the exhausted marker PD-1. Measurement of IL-1β and IL-6 serum levels among cases group showed a highly significant increase in their mean concentration levels in comparison with the control group. Studying the difference in serum levels of IL-1β and IL-6 among different degrees of disease severity showed a significant decrease in their mean concentration levels among the mild to moderate group in comparison with the severe to critical group. The results also showed a significant decrease in miR-146a and a significant increase in miR-133a expression in COVID-19 patients compared to healthy controls. Reduced T cell counts, increased CD4 + :CD8 + ratio, higher levels of the PD-1 marker, elevated serum levels of the pro-inflammatory cytokines, and decreased miR-146a and increased miR-133a gene expressions could be used as potential markers in the assessment of COVID-19 infection and severity.