Neutralizing Autoantibodies against Interleukin-10 in Inflammatory Bowel Disease

SummaryWe discovered high-titer neutralizing autoantibodies against interleukin-10 in a child with infantile-onset inflammatory bowel disease (IBD), a phenocopy of inborn errors of interleukin-10 signaling. After B-cell–depletion therapy and an associated decrease in the anti–interleukin-10 titer, conventional IBD therapy could be withdrawn. A second child with neutralizing anti–interleukin-10 autoantibodies had a milder course of IBD and has been treated without B-cell depletion. We conclude that neutralizing anti–interleukin-10 autoantibodies may be a causative or modifying factor in IBD, with potential implications for therapy. (Funded by the National Institute for Health and Care Research and others.)