Researchers believe that infection with the novel coronavirus can cause long-term issues in the lungs’ tiny airways, even in patients who have only had a moderate infection.
This adds to a growing list of symptoms and consequences that can arise after a coronavirus infection, known as long COVID.
The most typical symptoms of extended COVID include shortness of breath, weariness, and “brain fog.”
Some people’s symptoms persist after they’ve been infected. Complications may occur weeks or months later for others.
The mechanisms of extended COVID and potential therapies are still being researched.
Another group of researchers looked into the impact of coronavirus infection on the brain in a recent study. Other researchers are experimenting with new treatments for extended COVID’s heart-related symptoms.
Lung damage in people with long COVID
Researchers used CT imaging to assess the lungs of 100 adults with COVID-19 who had symptoms for at least 30 days following their diagnosis, according to a study published March 15 in the journal Radiology.
The findings of these persons’ CT scans were compared to those of a group of 106 healthy people.
When compared to healthy people, those who had COVID-19 — even if they were not hospitalized for it — were more likely to have evidence of damage in the tiny airways of the lungs.
In a news release, study author Dr. Alejandro P. Comellas, a pulmonologist and professor of internal medicine at the Carver College of Medicine at the University of Iowa, said, “There is some illness happening in the small airways independent of the severity of COVID-19.” “We need to look into it more to determine if it’s just a passing fad or something more lasting.”
There were 67 patients in the COVID-19 group who had never been hospitalized, 17 who had been hospitalized but not in the intensive care unit, and 16 who had been treated in the ICU.
Breathing difficulties, weariness, and cough were the most common symptoms in persons with lengthy COVID.
On CT scans, over 35% of the hospitalized participants showed symptoms of air trapped in their lungs, compared to 7.2 percent of the healthy patients.
Air trapping was seen in about 25% of participants who had a coronavirus illness but weren’t hospitalized.
When people breathe out, they are unable to completely empty their lungs. This is known as air entrapment. Chronic obstructive pulmonary disease (COPD), asthma, and other obstructive airway illnesses are examples of this.
Eight out of nine persons who received a CT scan more than 200 days after being diagnosed with COVID-19 still had air trapped in their lungs.
A further examination of the CT scans revealed signs of small airway illness linked to pulmonary inflammation or fibrosis. The latter is a disease in which the lung tissue is scarred and destroyed.
The participants will be followed up on to evaluate if their lung function improves or if their symptoms persist.
“We need to look at the processes behind small airway illness if a portion of people continues to have it,” Comellas added.
“It may be something reversible like inflammation, or it could be something irreversible like a scar, and then we need to look at ways to stop the disease from progressing,” he explained.
Neurological complications of long COVID
Another common symptom of chronic COVID is “brain fog,” although it isn’t the only neurological symptom that people suffer.
People with lengthy COVID also reported headaches, numbness or tingling, loss of sense of smell or taste, muscle discomfort, and anxiety or sadness, according to a study published in March 2021 by researchers at Northwestern University Feinberg School of Medicine.
The severity of neurological consequences encountered with extended COVID varies, according to Barbara Hanson, Ph.D., a researcher at Northwestern University Feinberg School of Medicine’s Ken & Ruth Davee Department of Neurology.
“Some of our patients are extremely handicapped by their symptoms, particularly cognitive problems,” Hanson added. “We’ve had some patients who have trouble writing and reading, keeping schedules, and completing their former occupations,” says the doctor.
“And then there are those who may simply be tired.” While some of that could be due to cognitive issues, weariness is the most common complaint,” she added.
Neurological issues, like other long-term COVID symptoms, can emerge in persons who had had a moderate initial infection and were not hospitalized, according to Hanson.
“Any of the symptoms at the outset of the acute infection have no bearing on the experience of long COVID,” she explained.
This was the case in a study published March 7 in the journal Neurology: Neuroimmunology & Neuroinflammation by Hanson and her colleagues.
“When those with mild to intermediate COVID-19 had protracted COVID, they had exactly the same results [as people with more severe COVID-19],” she said. “In reality, they had a higher number of symptoms and the subjective impression that they hadn’t improved.”
Researchers assessed several biomarkers related to brain health in this study, including one that signals that neurons have been damaged.
Glial cells, or supporting cells in the brain, are activated by another biomarker. Multiple sclerosis and other brain illnesses cause an increase in these cells.
Researchers created a “neuroglial score” by combining these biomarker measurements.
Persons hospitalized for COVID-19 who had an acute brain impairment known as encephalopathy, people with long COVID who had never been hospitalized for COVID-19, and healthy people from the community were among the 64 participants in the study.
The neuroglial score was found to be connected with anxiety in patients with lengthy COVID – people with anxiety symptoms had a higher neuroglial score.
This link held up when researchers took into account a participant’s age, gender, and BMI, as well as different anxiety measurements.
This, according to Hanson, indicates that the two have a “genuine relationship.”
The symptoms of COVID are quite real to persons who have had it for a long time. However, because extended COVID is a collection of illnesses rather than a single sickness, correct identification may be challenging.
Being able to point to a biomarker that is linked to a long-term COVID symptom like anxiety may provide some relief.
“Having biological evidence that says, ‘Yes, we can see from markers in your blood that it appears as if you are likely suffering anxiety as a result of lengthy COVID,’ is really validating,” Hanson said.
She does warn, however, that these biomarkers are not yet a “test” for extended COVID. Nonetheless, she claims that they provide more information about one feature of extended COVID.