Abstract 16418: Passive Transfer of Affinity-Purified Anti-Heart Autoantibodies (AHA) from Sera of Patients with Myocarditis Induces Experimental Myocarditis in Mice
Human autoimmune myocarditis is characterized by an increased frequency of serum organ and disease-specific anti-heart autoantibodies (AHA) in affected patients. Purpose: The aim of this study was to assess whether affinity-purified serum anti-heart autoantibodies (AHA) from patients with biopsy-proven myocarditis are directly pathogenic, using the passive transfer technique to normal Balb/c mice to induce an experimental myocarditis.
Methods: Sera from 5 AHA positive myocarditis patients (3 male, mean age 30±11 years, 3 with giant cell and 2 with lymphocytic myocarditis) and from 5 healthy donors were affinity purified and injected into Balb/c mice. In all patients cardiac-specific AHA had been previously detected by an indirect immunofluorescence (IFL) technique on cryostat sections of O blood group human heart and skeletal muscle. For each patient 5 mice were passively transferred (n=25). Equally for each healthy donor 5 mice were passively transferred (n=25), in addition 15 control mice were injected with phosphate-buffered saline and 9 mice did not receive any injection. The animals were sacrified after 4 weeks and the hearts were blindly examined for histological evidence of myocarditis by an expert cardiac pathologist.
Results: Myocarditis was present in 13/25 (52%) of the mice from all 5 of the passively transferred groups. The findings of severe, moderate or mild myocarditis were more common among passively transferred (20%; 20% and 12%) mice than in control animals (2%, p=0.01; 0%, p=0.003; and 0%, p=0.04 respectively).
Conclusions: These findings provide new evidence for AHA-mediated pathogenicity in human myocarditis, according to Rose-Witebsky criteria.
- © 2012 by American Heart Association, Inc.