Rogue antibodies may cause some long COVID symptoms 

Rogue antibodies whitethorn beryllium to blasted for immoderate of agelong COVID’s pernicious symptoms. 

Two caller studies propose that antibodies that onslaught people’s ain tissues mightiness origin ongoing neurological issues that afflict millions of group pinch nan disease. 

When scientists transferred these antibodies from group pinch agelong COVID into patient mice, certain symptoms, including pain, transferred to nan animals too, researchers reported May 31 connected bioRxiv.org and June 19 connected medRxiv.org. 

Though scientists have previously implicated specified antibodies, known arsenic autoantibodies, arsenic suspects successful agelong COVID, nan caller studies are nan first to connection nonstop grounds that they tin do harm. “This is simply a large deal,” says Manali Mukherjee, a translational immunologist astatine McMaster University successful Hamilton, Canada, who was not progressive successful nan work. The papers make a bully lawsuit for therapies that target autoantibodies, she says.

The activity could besides offer “peace of mind to immoderate of nan long-haulers,” Mukherjee says. As personification who has endured agelong COVID herself, she understands that erstwhile patients don’t cognize nan origin of their suffering, it tin adhd to their anxiety. They wonder, “What nan hellhole is going incorrect pinch me?” she says.

With much than 200 documented symptoms that tin operation and lucifer successful seemingly endless mélanges, agelong COVID is an particularly difficult illness to crack (SN: 6/12/24). “Teasing retired nan mechanisms that lead to these symptoms has been nan existent challenge,” Mukherjee says. 

Some clues truthful acold person pointed to autoantibodies. These tin ramp up successful nan humor during a SARS-CoV-2 infection, but their levels often dial backmost down arsenic a personification recovers. In group pinch agelong COVID, though, scientists person shown that autoantibodies tin instrumentality astir agelong aft nan first unwellness has passed. 

But investigation truthful acold hasn’t revealed “whether these autoantibodies are specified bystanders aliases progressive contributors to agelong COVID symptoms,” wrote bioRxiv.org study coauthor Hung-Jen Chen of nan Amsterdam University Medical Center and his colleagues.

Working independently, Chen’s squad and immunologist Akiko Iwasaki’s group astatine Yale University each collected antibodies from dozens of group pinch and without agelong COVID, injected those antibodies into mice and past tested nan animals’ behaviors. 

Antibodies that came from patients who reported dizziness caused a noticeable nonaccomplishment of equilibrium successful mice, Iwasaki found. And some groups discovered that agelong COVID antibodies could make mice much delicate to pain. In an research by Iwasaki’s group that tested nan animals’ expertise to tolerate opinionated connected a basking plate, mice that received antibodies from agelong COVID patients showed signs of symptom aft astir 7 seconds, compared pinch astir 10 seconds successful mice that sewage antibodies from patient people. 

Those mice that became extra-sensitive to symptom mostly had received antibodies from patients who themselves had chronic pain, Iwasaki’s group reported. That enhanced sensitivity could beryllium owed to antibody attacks harming nerves. After injection, nan mice developed damaged nervus fibers successful nan skin. 

Scientists person proposed many hypotheses for what causes agelong COVID, including SARS-CoV-2 microorganism lingering successful nan tissues and nan reawakening of dormant herpes viruses (SN: 3/4/24). Those elements whitethorn still play a domiciled successful immoderate people’s agelong COVID symptoms, but for pain, astatine least, rogue antibodies look to beryllium capable to kick-start nan denotation each connected their own. It’s not an out-of-the-blue domiciled for autoantibodies; scientists fishy they whitethorn besides beryllium progressive successful different conditions that origin group pain, including fibromyalgia and myalgic encephalomyelitis/chronic fatigue syndrome.

But if doctors could place which agelong COVID patients person pain-linked autoantibodies, they could effort to trim nan magnitude circulating successful nan blood, says Iwasaki, who is besides a Howard Hughes Medical Institute investigator. “I deliberation that would really beryllium a crippled changer for this peculiar group of patients.” 

The activity represents a “very beardown level of evidence” that autoantibodies could origin harm successful group pinch agelong COVID, says Ignacio Sanz, an immunologist astatine Emory University successful Atlanta. Both he and Mukherjee would for illustration to spot nan findings validated successful larger sets of participants. And nan existent clincher, Sanz says, would travel from longer-term studies. If scientists could show that patients’ symptoms easiness arsenic these rogue antibodies vanish complete time, that’d beryllium an moreover surer motion of their guilt.