Mitochondrial DNA, a marker of complications
How does the test work? By measuring the amount of mitochondrial DNA in the blood. The results are available within 24 hours of the blood test. “When this DNA spills out of cells and passes into the bloodstream, it indicates that many cells are being destroyed in the body,” says Andrew E. Gelman, lead author of the study. “This inflammatory phenomenon would damage lung tissue ** and trigger respiratory distress. “
“In our study, the highest blood concentrations of mitochondrial DNA were found in severe cases. “And this regardless of the age, sex and state of health of the patients. Compared to Covid-19 patients without complications, “mitochondrial DNA concentrations were 10 times higher in patients with severe respiratory dysfunction and / or deceased, 6 times higher in intubated patients, 3 times higher high in patients admitted to intensive care ”.
Prevent severe cases and assess the effectiveness of treatments
This test would make it possible to refine the prevention of serious complications, and to anticipate the necessary treatments such as intubation, dialysis or medication in the event of hospitalization.
So far, the only indicators assessing predisposition to severe forms were vulnerability factors: age over 65, overweight, obesity, diabetes, cardiovascular disease, chronic respiratory disease (COPD), l immunosuppression in cancer, HIV / AIDS, cirrhosis or renal failure. Women who are more than 6 months pregnant (third trimester of pregnancy) are also considered to be at risk due to a lower immunity at this stage.
However, “young patients without any particular risk factor sometimes develop very severe or even fatal forms”, the researchers point out. In this sense, the blood test predictive of complications could save lives.
Another advantage is that this device would also be able to assess the effectiveness of the treatment: “the more effective a treatment, the more the blood concentration of mitochondrial DNA decreases”.
Note: this test works on the same principle as the PCR tests carried out to assess positivity for Covid-19. “No DNA extraction is necessary. This process therefore remains easy to access and is not time-consuming ”, detail the scientists. This test must still be validated by the American drug agency, the Food and Drug administration (FDA), to perhaps soon land in France?
*Washington University School of Medicine in St. Louis
** This phenomenon is called necrosis and can also affect the heart and kidneys