Complete elimination of cardiodepressant IgG3 autoantibodies by immunoadsorption in patients with severe heart failure

Background: Cardiodepressant IgG3 autoantibodies (CD-Abs) can be targeted by apheresis. Using blinded measurements of CD-Abs before and after immunoadsorption (IA), the cardiac function of patients who did or did not achieve complete CD-Abs elimination was compared. Methods and Results: Autoantibodies were completely removed from 18 patients with heart failure (New York Heart Assocation class 3 or 4, left ventricular ejection fraction (LVEF) <30%) using a selective IgG3 adsorption column. All patients had anti-β1-adrenergic and/or M2-muscarinic autoantibodies before IA, and all LVEF were measured on radionuclide ventriculography. CD-Abs were measured before and after IA, and patient status was blinded until all measurements were collected. Treatment was defined as complete when CD-Abs status changed from positive to negative after IA. Other instances were defined as incomplete. Six-min walk test results and brain natriuretic peptide levels improved significantly after IA (P<0.01). The increase in LVEF 3 months after IA was significantly greater after complete treatment in comparison to the incomplete treatment group (19±8-29±9% vs 18±9-17±8%, P<0.01). Cardiac insufficiency events were also more frequent in the incomplete treatment group. Conclusions: Complete elimination of CD-Abs with apheresis may be related to improved cardiac function in the treatment of heart failure.