Myocarditis, microbes and autoimmunity

Area of Science:

• Cardiology
• Immunology
• Infectious Diseases

Background:

• Myocarditis, encompassing acute and chronic forms, stems from diverse infectious agents like viruses, bacteria, and protozoa.
• Current treatments for myocarditis are often ineffective, highlighting the need for deeper mechanistic understanding to develop targeted therapies.
• Understanding the pathological inflammatory responses is crucial for advancing myocarditis treatment strategies.

Purpose of the Study:

• To review three distinct infectious myocarditides with shared characteristics.
• To critically evaluate the proposed role of autoimmunity in myocarditis pathogenesis.
• To propose alternative mechanisms for myocardial damage in infectious myocarditis.

Main Methods:

• Literature review of infectious myocarditides.
• Analysis of common features across different infectious myocarditides.
• Critical evaluation of existing data on autoimmune responses in myocarditis.

Main Results:

• Identified common features in three infectious myocarditides: cardiac microbial replication, difficulty in isolating infectious agents during chronic disease, and presence of autoreactive antibodies and T cells.
• Challenged the prevailing hypothesis that autoreactive responses are the main effectors of cell death and myocardial damage.
• Highlighted the need to reconcile findings without solely relying on autoimmunity as an effector mechanism.

Conclusions:

• The proposed role of autoimmunity in infectious myocarditis requires re-evaluation.
• Alternative hypotheses for myocardial tissue destruction in infectious myocarditis are presented.
• Further research is needed to elucidate the precise mechanisms underlying infectious myocarditis and guide therapeutic development.