A scientist in South Africa believes she and her colleagues have found a critical clue in solving the mystery of long COVID: microclots.
“A recent study in my lab revealed that there is significant microclot formation in the blood of both acute COVID-19 and long COVID patients,” Resia Pretorius, head of the science department at Stellenbosch University in South Africa, wrote Wednesday in an op-ed.
Pretorius writes that healthy bodies are typically able to efficiently break down blood clots through a process called fibrinolysis. But, when looking at blood from long COVID patients, “persistent microclots are resistant to the body’s own fibrinolytic processes.”
Pretorius’ team in an analysis over the summer found high levels of inflammatory molecules “trapped” in the persistent microclots observed in long COVID patients, which may be preventing the breakdown of clots.
Because of that, cells in the body’s tissues may not be getting enough oxygen to sustain regular bodily functions, a condition known as cellular hypoxia.
“Widespread hypoxia may be central to the numerous reported debilitating symptoms” of long COVID, Pretorius writes.
As many as 100 million people globally have or have had long COVID, according to a study by researchers at the University of Michigan in November.
A patient is diagnosed with long COVID when the effects of a COVID-19 infection persist for more than four weeks, according to the Mayo Clinic. While older people and people with serious medical conditions are the most likely to experience long COVID, many young and healthy people have reported feeling unwell for weeks or even months after their initial COVID-19 diagnosis.
Symptoms of long COVID vary between cases, but primarily include fatigue, brain fog, muscle or joint pain, shortness of breath, sleep difficulties, and depression or anxiety.
The Department of Health and Human Services in June released new guidance in which some symptoms of long COVID could qualify as a disability under the Americans with Disabilities Act.
In December, the Equal Employment Opportunity Commission issued an update to its own guidance, which now considers an individual who has contracted COVID-19 disabled if any of their symptoms “substantially limits one or more major life activities.”