DSG1 and thrombotic thrombocytopenic purpura: This has raised the concern the binding of unrelated antibodies to Dsg-proprotein could lead to false positive detection of anti-Dsg3 or 1 antibodies, as has been shown for anti-Dsg1 in healthy controls and patients with the unrelated autoimmune disease thrombotic thrombocytopenic purpura (35).