CLEVELAND — It's known as long-haul COVID, patients struggling with a wide range of debilitating, potentially dangerous symptoms several months after contracting the virus.
A study by researchers at National Jewish Health published in the American Journal of Respiratory and Critical Care Medicine may help determine the cause behind these long-term symptoms that could lead to better treatments.
"There is no common characteristic among those experiencing post-COVID syndrome," Dr. Irina Petrache, MD, chief of the Division of Pulmonary at National Jewish Health and a co-author of the study, said. "We see patients who are young and old, those with mild and severe cases of COVID, and those who are active and healthy as well as some with pre-existing conditions.
"Some have subtle symptoms, while others experience very obvious, life-altering health issues that keep them from returning to their normal day-to-day life. For most, initial testing of their heart and lungs was normal, so we looked deeper to the cellular level."
Researchers conducted exercise testing at the National Jewish Health Center for Post-COVID Care and Recovery, monitoring hundreds of data points as patients became fatigued on an exercise bike. Patients wore a specialized mask and electrodes that monitored their breathing and heart function, and in some patients, an arterial line was also inserted to track blood oxygen levels.
They concluded that mitochondria—organelles in cells that are responsible for generating energy—did not function properly in patients with post-COVID syndrome. While the test revealed this dysfunction in muscle tissue, researchers believe this same process is related to symptoms originating in the pulmonary and neurological systems as well.
Researchers will build upon the discoveries in the current study to better understand how the virus alters cells and how those effects can be reversed or repaired.