Research Suggests Errant Antibodies May Be to Blame for Some Long COVID Symptoms

New research from UVA’s School of Medicine suggests that “errant antibodies that regulate chemical reactions the way enzymes do could explain low blood pressure and other persistent symptoms that plague patients after COVID.”

Researchers had previously discovered that some people’s nervous systems produce so-called “abzymes” after COVID-19 infections. Since enzymes control chemical reactions, the production of antibodies with enzymatic activity could “negatively affect many important bodily processes.” This new research confirms “the presence of abzymes in patients convalescing from COVID and found that the enzymatic activity of the antibodies correlated with blood-pressure problems.”

Up to 7% of people “with COVID-19 go on to develop Long COVID, which can come with a wide array of symptoms, including persistent respiratory problems, exhaustion, “brain fog,” and difficulties with blood-pressure control.” This new research points to abzymes as a potential culprit, since they “target the well-known spike protein the virus uses to invade our cells. To infect a cell, the spike binds another protein called Angiotensin Converting Enzyme 2, or ACE2, on the surface of the cell.”

ACE2 “helps the body regulate blood pressure. Because the spike protein specifically binds ACE2, that means that the spike protein has a negative partial copy of the part of ACE2 that binds the spike protein.” These abzymes may trick the body into believing they are ACE2. More than half of the blood samples investigated from 20 volunteers who had long-lasting respiratory symptoms post-COVID showed enzymatic activity characteristic of ACE2, and those with higher ACE2-like abzyme activity were then “more likely to experience decreases in their systolic blood pressure, rather than the increase normally associated with exercise.”