Coronavirusis now claiming around 100 lives a day in the UK. And, while vaccines may be doing their job at keeping most people free from severe illness, researchers are still curious to determine the causes and predictions of COVID related death in hopes of uncovering possible therapies.
Researchers from the University of Arizona, Stony Brook University, and Wake Forest University School of Medicine have recently found that the enzyme phospholipase A2 group IIA, known as sPLA2-IIA, could predict severe severity COVID-19 infection and even death.
What is sPLA2-IIA?
sPLA2-IIA is an enzyme - similar to that found in rattlesnake neurotoxin - commonly found in low amounts in healthy individuals and is a crucial defence against bacterial infection. But, in large quantities, it can trigger a dangerous inflammatory response and shred vital organs’ membranes.
Floyd Chilton, the senior author of the paper and director of the University of Arizona Precision Nutrition and Wellness Initiative, explained:
It's a bell-shaped curve of disease resistance versus host tolerance. In other words, this enzyme is trying to kill the virus, but at a certain point it is released in such high amounts that things head in a really bad direction, destroying the patient's cell membranes and thereby contributing to multiple organ failures and death.
Study discovers highest sPLA2-IIA levels in severe COVID patients
To conduct the study, researchers gathered data on 127 patients hospitalised at Stony Brook University between January and July 2020. The team then drew on a second cohort of 154 patients from StonyBrook and Banner University Medical Centre between January and November 2020. Dr Chilton went on:
These are small cohorts, admittedly, but it was a heroic effort to get them and all associated clinical parameters from each patient under these circumstances. As opposed to most studies that are well planned out over the course of years, this was happening in real time on the ICU floor.
Researchers then used algorithms to analyse the patient’s data, including age, BMI, pre-existing medical conditions, as well as each patient’s enzyme and lipid metabolite levels.
The study explained that most healthy individuals would have a level of sPLA2-IIA at just half a nanogram per millilitre. Research showed that coronavirus was lethal for 63% of the study’s participants that suffered from severe infection, with sPLA2-IIA present at ten nanograms per millilitre.
Dr Chilton exclaimed: ‘Many patients who died from COVID-19 had some of the highest levels of this enzyme that have ever been reported.’
It shared a high sequence homology to the active enzyme in rattlesnake venom and, like venom coursing through the body, it has the capacity to bind to receptors at neuromuscular junctions and potentially disable the function of these muscles.
Although the study has found a relation between the enzyme and severe coronavirus infection that could potentially predict COVID death, it has yet to draw any causal conclusions.
However, the study has provided a gateway for further research on how the enzyme affects COVID patients and potential treatments. Dr Chilton added that the research team is now looking at how sPLA2-IIA could potentially affect long-COVID sufferers:
Roughly a third of people develop long-COVID, and many of them were active individuals who now can’t walk 100 yards. The question we are investigating now is: If this enzyme is still relatively high and active, could it be a response to part of the long-COVID outcomes that we’re seeing?