Blood Tests for Brain-Injury Biomarkers Could Be Used to Monitor Patients with Moderate to Severe COVID-19

Some COVID-19 patients exhibit clinical and neurochemical signs of brain injury, according to a new study which showed that finding and measuring a blood-based biomarker for brain damage proved to be possible.
In the study by researchers at the University of Gothenburg (Gothenburg, Sweden), blood samples were taken from 47 patients with mild, moderate and severe COVID-19 in the course of their hospital stay. These samples were analyzed by means of highly sensitive biomarkers for brain injury. The results were compared with those from a healthy control group comprising 33 people matched by age and sex. The researchers found that an increase in one of the biomarkers took place even with moderate COVID-19 - that is, in patients admitted to hospital but not in need of ventilator support. This marker, known as GFAP (glial fibrillary acidic protein), is normally present in astrocytes, a star-shaped neuron-supportive cell type in the brain, but leaks out in the event of astrocytic injury or overactivation.

The second biomarker investigated was NfL (neurofilament light chain protein), which is normally to be found inside the brain’s neuronal outgrowths, which it serves to stabilize, but which leaks out into the blood if they are damaged. Elevated plasma NfL concentrations were found in most of the patients who required ventilator treatment, and there was a marked correlation between how much they rose and the severity of the disease. The researchers believe that blood tests for biomarkers associated with brain injury could be used for monitoring patients with moderate to severe COVID-19, to reduce the risk of brain injury.

“The increase in NfL levels, in particular, over time is greater than we’ve seen previously in studies connected with intensive care, and this suggests that COVID-19 can in fact directly bring about a brain injury. Whether it’s the virus or the immune system that’s causing this is unclear at present, and more research is needed,” said Henrik Zetterberg, Professor of Neurochemistry, whose research team performed the measurements.

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University of Gothenburg