Recovered, but not healthy – this is how long-Covid patients fare. So far there are only theses about what exactly triggers Long Covid. A recent study provides new clues.
It is not yet clear exactly why some people continue to have symptoms after a corona infection. But there are different assumptions as to what triggers Long Covid. A persistent infection, a disturbed immune reaction or an autoimmune reaction in which antibodies against Sars-CoV-2 do not attack the pathogen but the body’s own structures. Fatigue, concentration problems, but also hair loss and erectile dysfunction are among the range of symptoms that long-Covid sufferers experience. According to the World Health Organization, around ten to 20 percent of people who have been infected with corona suffer from medium- and long-term consequences after the disease.
A recent study provides new insights into long-term symptoms after a corona infection. A research team led by Akiko Iwasaki from Yale University carried out immunological tests in 99 long-Covid patients and a control group of 116 people. The control group included people who are completely healthy, as well as vaccinated and unvaccinated people who have survived corona infection without Long Covid. The study was published as a preprint and has not yet been reviewed by experts. However, the results are met with great interest. Federal Health Minister Karl Lauterbach wrote on Twitter: “Finally there is light in the Long Covid tunnel.”
Low Cortisol Levels in Long Covid
The long-Covid patients were infected with Covid-19 in 2020 and were mostly treated in hospital. They reported symptoms such as fatigue, brain fog and memory problems. The researchers noticed a low cortisol level in the long-Covid patients. Cortisol is commonly known as the stress hormone because it is released when we are stressed. But the hormone is also involved in many metabolic processes in the body.
Low cortisol levels are also found in people with chronic fatigue syndrome, which typically occurs after infection, reports Akiko Iwasaki. She also writes on Twitter that low cortisol levels could be a significant indicator to define long-Covid status and predict the severity of the disease.
reactivation of herpes viruses
The scientists also discovered that the antibodies that fight the Epstein-Barr virus were elevated in the long-Covid patients. These dormant herpes viruses in the body could be reactivated by a corona infection. It has been discussed in the past that the reactivation of these viruses could be related to the development of Long Covid.
In addition, the researchers discovered that long-Covid patients have differences in the concentrations of different immune cells. Among other things, the number of exhausted T cells is increased. According to Iwasaki, this is an indication that the cells are being stimulated by permanently present antigens.
Biomarkers for Long Covid
If the results of the study can be confirmed in further investigations, it could be a breakthrough in long-Covid research. Low cortisol levels, along with other levels, could serve as a biomarker for Long Covid. Biomarkers are used in medicine to see whether processes in the body are running normally – for example by measuring body temperature, blood pressure or hormones. If Long Covid could be detected using biomarkers, approaches for therapies could be developed.
“We hope that this data will help skeptics understand that Long Covid is real and has biological origins,” says Akiko Iwasaki.
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Source: Stern
