Figure 1.

Functional autoantibodies against G-protein-coupled receptors in children with MIS-C after COVID-19 and BNT162b2. Functional autoantibodies against G-protein-coupled receptors in a boy with MIS-C after BNT162b2 vaccination (Case1), and the mean of four published children with MIS-C after COVID-19. Compared to healthy controls, anti-angiotensin 1 receptor, anti-endothelin, and anti-β adrenergic receptor autoantibodies were elevated. Additionally, elevated anti-α1 adrenergic receptor and anti-muscarinic cholinergic receptor-3/4 autoantibodies were only measured in the four children with MIS-C after COVID-19. Anti-AT1R: anti-angiotensin 1 receptor autoantibody; anti-ETAR: anti-endothelin receptor autoantibody; anti-α1 adrenerg: anti-α1 adrenergic receptor autoantibody; anti-α2 adrenerg: anti-α2 adrenergic receptor autoantibody; anti-β1 adrenerg: anti-β1 adrenergic receptor autoantibody; anti-β2 adrenerg: anti-β2 adrenergic receptor autoantibody; anti-MC R1: anti-muscarinic cholinergic receptor-1 autoantibody; anti-MC R2: anti-muscarinic cholinergic receptor-2 autoantibody; anti-MC R3: anti-muscarinic cholinergic receptor-3 autoantibody; anti-MC R4: anti-muscarinic cholinergic receptor-4 autoantibody; anti-MC R5: anti-muscarinic cholinergic receptor-5 autoantibody.