RTHM
A recent study published in Cell Reports Medicine adds to a growing set of antibody-transfer studies that suggest autoimmunity could be playing a role in driving Long COVID symptoms. Researchers isolated IgG antibodies (a major class of antibodies) from people with Long COVID and transferred them into healthy mice. In some conditions, these antibodies can become autoantibodies, meaning they mistakenly target the body’s own tissues instead of (or in addition to) something foreign like a virus or bacterium. After receiving IgG from Long COVID patients, the mice developed symptoms that resembled some of those seen in Long COVID, including fatigue-like behavior and changes in pain sensitivity. Antibodies from different subgroups of Long COVID patients caused different symptom patterns in the mice, suggesting that different antibody profiles may contribute to different presentations of Long COVID. The findings do not prove that all Long COVID is caused by autoantibodies, and mouse studies still need to be validated in humans. But the studies do add to a growing number of antibody-transfer studies that provide functional evidence that antibodies from Long COVID patients may directly contribute to symptoms. More research in this area could potentially open the door to more targeted treatment approaches based on antibody subgroups, including therapies that remove, block, or neutralize harmful IgG. Read the full study: https://doi.org/10.1016/j.xcrm.2026.102693
