Long COVID: UNamur-CHU UCL Namur collaboration uncovers key mechanisms behind chronic pain

Researchers from UNamur and CHU UCL Namur, working within NARILIS, have just published a major study in Acta Neuropathologica shedding new light on the biological origin of chronic pain in long COVID patients (Mignolet et al., 2026 “Pathogenic IgG from long COVID patients with neurological sequelae triggers sensitive but not cognitive impairments upon transfer into mice”).

This work is the result of a multidisciplinary collaboration combining the clinical expertise of Prof. Pierre Bulpa (Intensive care, CHU UCL Namur) and the neuroscience expertise of Prof. Charles Nicaise (Neurodegeneration and Regeneration lab, UNamur). The project was initiated in 2022 through the doctoral research of Margaux Mignolet, who investigated the hypothesis that immune dysregulation occurring during SARS-CoV-2 infection could lead to the production of autoantibodies that target the nervous system.

To test this hypothesis, 13 long COVID patients were recruited at the hospital with the support of Catherine Deroux (Memory Clinic, CHU UCL Namur). Blood samples were collected and IgG antibodies were isolated before being transferred into mice at the Life Sciences Technology Platform (PTSV) of UNamur.

The results demonstrate that IgGs from long COVID patients bind to peripheral sensory neurons located in the lumbar dorsal root ganglia and induce pain-related symptoms in mice. Animals receiving these antibodies developed increased mechanical and thermal sensitivity.

Overall, the findings support an autoimmunity mechanism in which autoantibodies targeting sensory neurons contribute to persistent pain symptoms in long COVID patients. They also point to lumbar dorsal root ganglia sensory neurons as the cellular targets, opening new avenues for identifying the specific antigens involved.

These highly promising results represent a significant scientific breakthrough, paving the way for a better understanding of long COVID and, ultimately, the development of targeted therapies to reduce chronic pain symptoms.

On May 11, 2026, Margaux Mignolet has been invited by the Belgian Senate to contribute to discussions surrounding a proposed resolution aimed at improving the care and treatment of Long COVID patients. https://www.youtube.com/watch?v=5jL8_EamhWo