The method allows the levels of mitochondrial DNA to be quantified directly in the blood, without the need for intermediate steps.
In a recent study published in the journal JCI Insight, the researchers demonstrated that a simple blood test that gives rapid results can predict within a day of hospital admission which patients with coronavirus 2019 (COVID-19) are at the greatest risk of developing serious complications or death. The study was conducted at the University of Washington School of Medicine in St. Louis.
The study consisted of 97 patients who were recently admitted to Barnes-Jewish Hospital with a confirmed case of COVID-19. The blood test used measures the patient’s mitochondrial DNA levels, a single molecule that normally resides in a cell’s energy factories. When these molecules begin to leak into the bloodstream, it is a good indication that some form of violent cell death is occurring somewhere in the body.
“Doctors need better tools to assess the status of patients with COVID-19 as early as possible because many of the treatments – such as monoclonal antibodies – are scarce and we know that some patients will improve without intensive treatment.” Andrew E. Gelman, senior co-author of the study, said. “There is so much that we still don’t understand about this disease. In particular, we need to understand why some patients, regardless of their age or underlying health in some cases, enter this spiral of hyperinflammatory death.”
The results of the study showed that the levels of mitochondrial DNA were significantly higher in patients who were eventually admitted to the ICU, intubated or died. The levels of those who developed severe lung dysfunction or died were, on average, 10 times higher. They also had 6 times more chance of intubation, 3 times more chance of being admitted to the ICU and almost 2 times more chance of dying compared to those with lower levels.
In addition, the blood test was able to predict patient outcomes as well or even better than the existing markers of inflammation that are currently measured in hospitalized patients.
“Viruses can cause a type of tissue damage called necrosis, which is a violent inflammatory response to infection. The cell breaks down, releasing the content, including mitochondrial DNA, which in itself leads to inflammation, ”said Gelman. “In COVID-19 patients, there was anecdotal evidence of this type of cell and tissue damage in the lung, heart and kidney. We think it is possible that the measurements of mitochondrial DNA in the blood are an early sign of this type of cell death in vital organs. “