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

## TL;DR

This study identifies immune and genetic markers that may help assess the severity of COVID-19 in Egyptian patients.

## Contribution

The study identifies specific immunological and miRNA changes associated with varying severity levels of COVID-19 in Egypt.

## Key findings

- CD4+ and CD8+ T cell counts were reduced in COVID-19 patients, especially in severe cases.
- Serum levels of IL-1β and IL-6 were significantly higher in severe to critical patients.
- miR-146a was decreased and miR-133a was increased in COVID-19 patients compared to healthy controls.

## Abstract

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.

The online version contains supplementary material available at 10.1038/s41598-025-34444-y.