Moving the needle forward
Commenting on the findings, William Schaffner, MD, professor of infectious diseases, Vanderbilt University Medical Center, Nashville, Tenn., said that, while the study doesn’t rule out a possible psychological basis for cognitive PASC, it adds more weight to the biological argument.
“When you have nonspecific symptoms for which specific tests are unavailable,” Dr. Schaffner explained, “there is a natural question that always comes up: Is this principally a biologically induced phenomenon or psychological? This moves the needle substantially in the direction of a biological phenomenon.”
Another important element to the study, Dr. Schaffner said, is that the patients involved had mild COVID.
“Not every patient with long COVID symptoms had been hospitalized with severe disease,” he said. “There are inflammatory phenomenon in various organ systems such that even if the inflammatory response in the lung was not severe enough to get you into the hospital, there were inflammatory responses in other organ systems that could persist once the acute infection resolved.”
Although the small size of the study is a limitation, Dr. Schaffner said that shouldn’t minimize the importance of these findings.
“That it’s small doesn’t diminish its value,” he said. “The next step forward might be to try to associate the markers more specifically with COVID. The more precise we can be, the more convincing the story will become.”
The study was funded by the National Institutes of Health. Dr. Hellmuth received grant support from the National Institutes of Health/National Institute of Mental Health supporting this work and personal fees for medical-legal consultation outside of the submitted work. Dr. Schaffner disclosed no relevant financial relationships.
A version of this article first appeared on Medscape.com.