Patients who have had difficulty recovering after COVID-19 frequently discover that doctors regard them like medical mystics. Routine testing frequently shows nothing abnormal, leading doctors to incorrectly conclude that Long COVID may be a type of depression or anxiety or that it is simply all in the patient’s brain.
Now, two small but incredibly thorough studies are shedding light on the biology underlying long-term COVID and, if replicated, could point to potential biomarkers for the chronic condition, which, according to the most recent statistics from the US Centers for Disease Control and Prevention, affects an estimated 6% of all American adults, or more than 15 million people.
“This is some validation for the community that this isn’t just a bunch of people who are complaining a lot. There are biological differences between people who have persistent fatigue, cognitive issues, and POTS, and I think that is important,” said Dr. Daniel Griffin, an infectious disease expert at Columbia University who treats patients with long Covid but was not involved in the new studies.
Testing Blood Samples
The first study, conducted by Yale and Mount Sinai researchers and published in Nature, compared blood samples from 273 individuals who were divided into three main groups: those who met strict criteria for a diagnosis of long Covid, those who had Covid-19 but recovered completely, and individuals with no signs of infection.
People who participated in the study and tested positive for COVID-19, according to the researchers, had typically mild initial illnesses, and blood samples were typically taken more than a year after they became ill. Participants in the study also provided thorough responses to questions regarding their symptoms. Fatigue, brain fog, memory loss, and postural orthostatic tachycardia syndrome were the three most frequent complaints among participants in the long Covid group.
They adopted an exploratory strategy, which meant they examined a wide range of variables across the patient groups, including hormones, immunological activity, and other infections, rather than conducting specific tests. To organize the enormous volumes of data they produced, they used a form of artificial intelligence.
Further Questions on Long COVID
Immune dysregulation was also present in the extended Covid group. In deep immunological profiling, those with long COVID had reduced amounts of conventional type 1 dendritic cells and larger levels of non-conventional monocytes, which are immune cells. Many additional differences were discovered throughout testing, which further suggested an immunological imbalance.
Additionally, the long Covid group exhibited immunological alterations that could have been caused by viruses like the Epstein-Barr virus, which causes mononucleosis and is well recognized for its crippling lethargy, reawakening in their bodies. Up to 95% of adults are carriers of the latent Epstein-Barr virus.
“When you have low levels of cortisol, you will get tiredness, nausea, vomiting, weight loss, weakness, and pain,” said senior study author Dr. Akiko Iwasaki, an immunobiologist at Yale School of Medicine, “noting that those are some of the same features of long Covid. “So lower levels of cortisol could be contributing to the symptoms.”
