Abatacept alleviates severe autoimmune symptoms in a patient carrying a de novo variant in CTLA-4

Notably, there was a recent case report on abatacept treatment in an adult with idiopathic autoimmune enteropathy.7 To investigate the molecular effect of the drug, we sampled the patient's blood at the trough level (ie, 0 day) and at 1, 4, 6, and 8 days (among these, samples from the trough level and days 4 and 8 were subjected to the fluorescence-activated cell sorting analysis) after the administration of the drug (Fig 2, A-D; for drug treatment details, see the Methods section in this article's Online Repository at www.jacionline.org). Here we report a direct effect of CTLA-4 dysfunction in human; enhancing the CTLA-4-mediated signal with CTLA-4-Ig toned down immune responses in a patient with severe autoimmune features, eventually achieving substantial clinical improvements. [...]it would be worthwhile to investigate patients with idiopathic autoimmune features for additional CTLA-4 mutations that may affect proper protein function and use CTLA-4-Ig as a potential therapeutic solution.