A team of researchers at the University of Liverpool have identified a transcriptomic biomarker in the blood of patients infected with the Ebola virus, which may be a predictor of survival. According to the publication of the research – which was featured in the journal, Genome Biology – the expression of a select number of genes is an accurate predictor of whether the infection will be fatal, regardless of the viral load.
The researchers collected samples from Ebola-positive patients between 2013 and 2016 – the peak of the West African outbreak. In analyzing the blood samples, the researchers sought to identify gene transcripts which could predict patient outcomes.
Like many viral infections, the mortality of the Ebola virus is closely linked to the amount of the pathogen present in the body. Patients with a higher viral load are less likely to recover, compared to those with a lower burden of the pathogen.
But for patients whose viral count falls between these two extremes, viral load becomes a less accurate predictor of mortality. By studying the characteristics of blood samples collected from Ebola patients who either survived or succumbed to the infection, the researchers hoped to find a useful biomarker.
The patient blood samples were analyzed using RNA-Seq to both identify and quantify mRNA transcripts. The mRNA expression in these patients was then compared to blood samples collected from Ebola survivors after they were determined to be clear of the virus.
“It is not just defining how much Ebola virus that is present in a patient that defines whether a patient will survive. How the patient fights the infection is also key,” said Dr. John Connor, associate professor of microbiology, Boston University School of Medicine, and one of the authors of the study. “Defining common aspects of how the immune system responds in individuals that survive opens a new window for studying how to keep Ebola virus infection from being a fatal infection.”
In addition to the transcriptomic signatures identified in patients who survived the infection, the researchers also identified some other key information about Ebola. They found that an immediate robust immune response against the Ebola virus was not an accurate predictor of future survival, and the infection was also found to cause substantial liver damage.
“This study helps us to further our understanding of the human response to Ebola virus infection,” said Professor Miles Carroll, Director of Research at Public Health England. “This understanding should enable more effective patient care resulting in improved clinical outcomes in future outbreaks.”
By identifying blood-based biomarkers which act as predictors of patient outcomes, healthcare workers in the future may be able to formulate better treatment strategies based on the results of this diagnostic. This technology could also be applied to other infectious disease outbreaks, potentially reducing the spread and severity of future epidemics.