People with chronic fatigue syndrome may have tiny clots in their blood. These 鈥渕icroclots鈥� could be responsible for the main symptoms of the condition, which include persistent exhaustion, pain and brain fog.
It is estimated that chronic fatigue syndrome, also known as myalgic encephalomyelitis or ME, affects up to , but little is understood about what causes it or how to treat it.
Microclots are clumps of blood platelets under 200 micrometres in diameter that are difficult to break up. Researchers have known for decades that microclots associated with inflammation such as diabetes, Alzheimer鈥檚 and rheumatoid arthritis. More recently, evidence suggests they may play a role in long covid too: blood samples from people with of these small platelet clumps.
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Since chronic fatigue syndrome shares numerous symptoms with long covid, including headaches, lethargy and memory problems, at Stellensbosch University in South Africa and at the University of Liverpool in the UK wanted to see if microclots were also found in people with this condition.
To do this, they and their colleagues analysed blood samples from 25 adults in South Africa who had been diagnosed with chronic fatigue syndrome and experienced symptoms for at least six months. They compared these with samples from 15 adults from the same area who didn鈥檛 have chronic fatigue syndrome or any other condition known to increase the risk of clotting.
First, the team analysed the samples from people with chronic fatigue syndrome for seven parameters of abnormal blood clotting, such as clot size and clotting rate. Blood from 20 of the 25 people fell outside the normal range on at least one of these parameters, and four people had abnormal results on five of the measures.
They also used fluorescent staining to reveal the size and number of microclots under a microscope. Samples were graded on a scale of 1 to 4 with higher scores indicating more clotting. All control blood samples scored a 1, but 80 per cent of the samples from people with chronic fatigue syndrome scored a 2 or higher and nearly half scored a 3 or 4.
The concentration of microclots they found wasn鈥檛 as severe as you would see in people with acute or long covid, says Pretorius. But it was similar to other conditions. 鈥淭he microclots we see in chronic fatigue syndrome are comparable to what we found in diabetes or cardiovascular disease,鈥� says Pretorius.
The finding is important for three reasons. First, it provides a possible explanation for the persistent exhaustion characteristic of chronic fatigue syndrome, says at Columbia University in New York. Microclots block small blood vessels. 鈥淸This] stops the ability of oxygen to get to tissues,鈥� says Kell, which undermines cell function.
Second, it validates for people with chronic fatigue syndrome that what they are feeling is real. 鈥淎 very large population of clinicians and psychologists say there is nothing physically wrong with individuals, it鈥檚 all in their heads,鈥� says Pretorius.
Finally, it may offer a potential avenue for treatment. Chronic fatigue syndrome may be a vascular clotting disease, says Pretorius. If future research confirms this, doctors may be able to use anti-clotting medications or other interventions to treat people with this condition, says Kell.
The usual notes of caution apply here. This was a small initial study and many people with chronic fatigue syndrome also have conditions such as psoriasis or heart disease, which can contribute to clotting. The next step is to carry out additional research with larger groups of people.
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