A blood test (cell free DNA) to detect heart inflammation in sarcoidosis

Sarcoidosis is a multisystem granulomatous disease of unknown cause that can affect any organ in the body, including the heart. Granulomatous myocarditis can lead to ventricular dysfunction and ventricular arrhythmias causing significant morbidity and mortality. Immunosuppressive therapy (IST) has been shown to reverse active myocarditis and preserve left ventricular (LV) function and in some cases improve LV function. In addition, IST can suppress arrhythmias that develop due to active myocarditis and prevent the formation of scar.

The potential role of cardiac biomarkers, including brain natriuretic peptide (BNP), atrial natriuretic peptide (ANP), and cardiac troponins, in detecting active myocarditis is limited and studies have been disappointing. At present, there are no biomarkers to detect active myocarditis and the use of advanced imaging modalities (FDG-PET) for assessing and monitoring active myocarditis is not feasible or practical and is associate with high radiation exposure. As such, a biomarker that is reflective of active myocarditis and that is cardiac specific will assist physicians in assessing the presence of active myocarditis to guide therapeutic decisions and to assess response to therapy which can limit further cardiac damage.

Cell free DNA (cfDNA) are fragments of genomic DNA that are released into the circulation from dying or damaged cells. It is a powerful diagnostic tool in cancer, transplant rejection and fetal medicine especially when the genomic source differs from the host. A novel technique that relies on tissue unique CpG methylation patterns can identify the tissue source of cell free DNA in an individual reflecting potential tissue injury. We will be conducting a pilot study to explore the utility of this diagnostic tool to identify granulomatous myocarditis in patients with sarcoidosis.