Researchers find something that could cause brain fog and fatigue
Unusual structures have been discovered in the blood of individuals suffering from long Covid. Medical researchers have spotted something peculiar under their microscopes that could be contributing to symptoms such as brain fog and fatigue.
Long Covid has remained a mystery since the pandemic hit, but unique biomarkers have now been identified that could support two probable theories, both of which could turn out to be accurate.
The first theory suggests that the malaise is caused by minuscule blood clots that obstruct blood flow, while another piece of the puzzle points to the possibility of sticky webs of DNA having a similar effect.
It’s still early days, but doctors are optimistic that if they can understand how these blood components impact long Covid, it could lead to potential treatments and even a cure.
In a study published in the Journal of Medical Virology, an international team led by Professor Alain Thierry of Montpellier University, in collaboration with South African physiologist Professor Resia Pretorius, analysed blood from 50 people with long Covid and 38 healthy volunteers, reports the Mirror.
What they found was a dramatic increase in the clots – nearly 20 times more compared to healthy blood – and they were larger too.
The clots are filled with ‘NETs’ – neutrophil extracellular traps – which are sticky webs of DNA and enzymes released by white blood cells to trap invading viruses.
Usually, NETs perform their function and then disintegrate. However, in these samples, the webs were physically embedded within the microclots, forming stubborn, gummy structures that could impede blood flow through capillaries and resist the body’s normal clean-up process.
The team utilised imaging flow cytometry and fluorescence microscopy to identify these entangled clots, discovering the NETs–microclot combination in all samples but far more pronounced in individuals with long Covid.
The difference was so significant that when the samples were anonymised, an AI system could identify the long Covid patients with approximately 91% accuracy. This suggests the possibility of a potential biomarker to assist doctors in diagnosing a condition that’s often dismissed because standard tests return ‘normal’.
In 2021, Pretorius’s team initially highlighted microclots in long Covid; in 2022, Thierry’s group reported elevated NETs. Now, merging those threads, the new study suggests the two may be collaborating in the blood – and when that partnership goes rogue, trouble ensues.


















































