Myocarditis and autoimmunity

ABSTRACT

Introduction

Autoimmune myocarditis may develop due to heterogeneous causes. Myocarditis is often caused by viral infections, but it can also be caused by systemic autoimmune diseases. Immune checkpoint inhibitors and virus vaccines induce immune activation, and they can cause the development of myocarditis, as well as several immune-related adverse events. The development of myocarditis is dependent on the genetic factors of the host, and the major histocompatibility complex (MHC) may be an important determinant of the type and severity of the disease. However, non-MHC immunoregulatory genes may also play a role in determining susceptibility.

Area covered

This review summarizes the current knowledge of the etiology, pathogenesis, diagnosis, and treatment of autoimmune myocarditis with a particular focus on viral infection, autoimmunity, and biomarkers of myocarditis.

Expert opinion

An endomyocardial biopsy may not be the gold standard for the diagnosis of myocarditis. Cardiac magnetic resonance imaging is useful in diagnosing autoimmune myocarditis. Recently identified biomarkers of inflammation and myocyte injury are promising for the diagnosis of myocarditis when measured simultaneously. Future treatments should focus on the appropriate diagnosis of the etiologic agent, as well as on the specific stage of the evolution of immune and inflammatory processes.

KEYWORDS:

• autoantibody
• atrial fibrillation
• biomarker
• COVID-19
• immune checkpoint inhibitor
• heart failure
• vaccine
• virus

Article highlights

• Autoimmune myocarditis may develop alone without any association with the involvement of other organs, but it might also be due to undetected infectious agents.

• Viral infection may play an important role in the pathogenesis of autoimmune myocarditis.

• Immune checkpoint inhibitors and virus vaccines can cause the development of autoimmune myocarditis.

• Genetic factors, especially the major histocompatibility complex (MHC), may be an important determinant of the type and severity of myocarditis.

• Endomyocardial biopsy is invasive, and it may not be the gold standard for the diagnosis of myocarditis.

• Dallas criteria for myocarditis are not satisfied in many cases of viral myocarditis.

• Cardiac magnetic resonance imaging is useful in diagnosing autoimmune myocarditis.

• Recently identified biomarkers of inflammation and myocyte damage show promise in the diagnosis of myocarditis when measured simultaneously

• Future treatments should focus on the appropriate diagnosis of the etiologic agent, as well as on the specific stage of the evolution of immune and inflammatory processes.

Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Additional information

Funding

This paper was not funded.