Viral causes of human myocarditis

Area of Science:

• Cardiology
• Virology
• Pathology

Background:

• Acute myocarditis diagnosis is complex, with traditional Dallas criteria showing limitations due to sampling errors and interpretation variability.
• Histological assessment alone has poor sensitivity and specificity for identifying the causes of myocarditis.

Purpose of the Study:

• To enhance the diagnostic accuracy of acute myocarditis.
• To investigate the utility of virological evaluations alongside traditional methods for improved etiological diagnosis.

Main Methods:

• Utilized endomyocardial biopsy (EMB) combined with histological Dallas criteria.
• Incorporated immunohistochemical and polymerase chain reaction (PCR) techniques, including real-time PCR and reverse transcription PCR, for viral detection in cardiac tissues.
• Analyzed viral markers for parvovirus B19, Coxsackie B virus, human herpesvirus 6 (HHV-6), and adenovirus.

Main Results:

• Parvovirus B19, Coxsackie B virus, HHV-6, and adenovirus were detected in 37%, 33%, 11%, and 8% of EMB samples, respectively, in young adults with acute myocarditis.
• Viral co-infections, predominantly parvovirus B19 and HHV-6, were identified in 12% of cases.
• Immunohistochemistry aids in differentiating active viral infections from latent infections.

Conclusions:

• Integrated virological analysis with EMB significantly improves the identification of myocarditis causes.
• These advanced diagnostic approaches facilitate the development of etiology-directed treatment strategies for acute myocarditis.