A number of factors can increase someone’s risk of developing lung COVID, aside from catching COVID itself. They include asthma, Type 2 diabetes, or autoimmune conditions, and being female.
Now researchers think that prior exposure to another coronavirus — one that causes a common cold — may play a role in some patients.
In the new study by Harvard University-affiliated scientists, published Sept. 26 at Yale University-affiliated preprint server medRxiv, authors tested the blood of 43 patients who had arthritis or a similar condition before the pandemic.
Such patients who later developed lung COVID showed evidence of an overwhelming antibody response to COVID—and of an overwhelming antibody response to OC43, one of several circulating coronaviruses that cause the common cold.
The patients were likely infected with the cold at some point in their lives before they were infected with COVID, the authors theorize. When their bodies’ immune systems were exposed to the SARS-CoV-2 coronavirus, which causes COVID, they responded with OC43 antibodies that, although similar, were less than ideal, leading to chronic inflammation and other chronic COVID -symptoms.
Dr. Eric Topol, a professor of molecular medicine at Scripps Research and founder and director of the Scripps Research Translational Institute, said the new findings come in a “very interesting report that adds to the possible underpinnings of lung COVID.”
Researchers have looked at prior infection with Epstein-Barr virus, a form of herpes that can cause mono, and other viruses as possible contributors to the development of lung COVID, Topol tweeted Sept. 26. But the new study is the first to look at the role a common cold can play.
There are thought to be multiple categories of long-term COVID with, perhaps, different triggers for each, except for COVID. While prior infection with this common cold may play a role in arthritis patients with chronic COVID, it may or may not play a role in other categories of patients, the authors wrote.
But especially for arthritis patients, the discovery could serve as a way to identify long-term COVID and possibly develop a treatment for it, she added.
Nearly 20% of U.S. adults who have had COVID — about 50 million Americans — report having long-term COVID symptoms after their infection resolves, according to data collected by the U.S. Census Bureau this summer.
Chronic COVID is roughly defined as symptoms that persist or appear long after the initial COVID infection has passed, but a consensus definition is not yet widely accepted.
Many experts argue that long COVID is best defined as a chronic fatigue syndrome-like condition that develops after COVID illness, similar to other post-viral syndromes such as those that can occur after infection with herpes, Lyme- disease, and even Ebola. Other post-COVID complications, such as organ damage and post-intensive care syndrome, should not be defined as long as COVID, they say.
Coronaviruses, named for their crown-like appearance under a microscope, were discovered in the 1960s. Four types, including OC43, commonly circulate among humans, and usually cause colds. Three additional coronaviruses contain more serious symptoms: MERS (Middle Eastern respiratory syndrome), which caused an epidemic in 2012; SARS (severe acute respiratory syndrome), which caused an epidemic in the early 2000s; and COVID.