Study links autoantibodies to long COVID symptoms ^{CEFR B1}

Since the COVID-19 pandemic, many people have reported long-term symptoms known as long COVID. A new study co-led by Yale researchers found strong evidence that, in a subset of patients, the immune system produces autoantibodies that attack brain and nerve tissues. These autoantibodies often targeted regions involved in pain signaling, memory, balance, sensory processing and control of the autonomic nervous system.

To reach these findings, the team analysed blood from people with long COVID, healthy volunteers and people who recovered without lasting symptoms. They purified antibodies and tested them on human and mouse tissues, and then screened samples against more than 21,000 human proteins. Antibodies from long COVID patients reacted more strongly with certain brain regions and nerve tissues than those from control groups.

In live tests, researchers transferred patient antibodies into healthy mice. The mice developed increased pain sensitivity, fatigue, impaired balance and small-nerve-fiber damage. The authors say the results could link long COVID to autoimmune processes and might point toward treatments used for some autoimmune diseases, but they stress that more research is needed.