A team of researchers have identified why some people with COVID-19 fare well, while others end up in critical care.

The team from NYU Abu Dhabi investigated the association between microRNAs, a class of small RNA molecules that regulate genes, and COVID severity among 259 unvaccinated COVID patients living in Abu Dhabi.

The findings, published in the journal Human Genomics, showed microRNAs that are associated with a weakened immune response and admission to ICU.

"This study demonstrates that microRNAs are promising biomarkers for disease severity, more broadly, and targets for therapeutic interventions," said Youssef Idaghdour, Associate Professor of Biology at the varsity.

During this process, they created the first genomic picture of the architecture of blood microRNAs in unvaccinated COVID patients from the Middle East, North Africa and South Asia regions whose populations are consistently underrepresented in genomics research.

The researchers then identified changes in microRNAs at the early stages of infection that are associated with specific blood traits and immune cell death, allowing the virus to evade the immune system and proliferate.

The results of the system's genetics study demonstrate that a patient's genetic make-up affects immune function and disease severity, offering new insights into how patient prognosis and treatment can be improved.

In the study, the team included the results of the analysis of multiple omics datasets -- genotypes, miRNA, and mRNA expression of patients at the time of hospital admission, combined with phenotypes from electronic health records.

The researchers analysed 62 clinical variables and expression levels of 632 miRNAs measured at hospital admission, as well as identified 97 miRNAs associated with eight blood phenotypes significantly associated with ICU admission.

"These findings improve our understanding of why some patients withstand COVID-19 better than others," said Idaghdour.

"The methods of this study can be applied to other populations to further our understanding of how gene regulation can serve as a core mechanism that impacts COVID-19 and, potentially, the severity of other infections," he added.