What causes long COVID? Case builds for rogue antibodies

Nature Study finds that antibodies from people with the debilitating condition trigger similar symptoms in mice.

Antibodies isolated from people with long COVID increase pain sensitivity and reduce movement in mice when transferred to the animals, research shows¹. The findings suggest that antibodies might drive some symptoms of long COVID — although how that process works is unclear, and the results will need to be replicated in larger studies.

“I think this will be a beacon of a paper that we can take forwards to further understand long COVID,” says Resia Pretorius, an immunologist at Stellenbosch University in South Africa.

Previous research has hinted that long COVID might be caused, at least in part, by autoantibodies — rogue antibodies that a person generates that attack their own immune system or tissues. But one big question remained: “Is it really causal?” says Jeroen den Dunnen, an infectious-disease researcher at the Amsterdam University Medical Center. In other words, do autoantibodies cause long COVID symptoms, or are they simply generated in response to a long COVID infection? Along with his colleagues, den Dunnen undertook the latest study to get an answer.