Rapid identification of myocarditis: the first evidence for a diagnostic blood test

By Dr Jonathan Shurlock

BHF funded research led by Professor Federica Marelli-Berg (Queen Mary University of London) has opened the door to new diagnostic approaches to inflammatory cardiomyopathies. The authors describe their approach to measuring and phenotyping peripheral blood T cells, with a particular focus on c-mesenchymal epithelial transition factor expressing (c-Met+) memory T lymphocytes, as these have been shown to preferentially migrate to the heart.

140 participants were grouped by cardiac presentation; autoimmune myocarditis (AM) (n=34), idiopathic dilated cardiomyopathy (n=31), acute ST-segment–elevation myocardial infarction (STEMI) (n=15), cardiac surgery (n=11), ischemic heart failure (n=8), active Sjögren syndrome (n=7) and familial cardiomyopathies (n=14). Diagnosis in the AM group was based on elevated serum troponin values and CMR evidence of myocarditis. 20 healthy controls were also included.

The authors found selective increase in both peripheral circulation and myocardium of c-Met+ T cells in participants with diagnosed AM. The authors further identified subpopulations of c-Met+ T cells which differ in expression across the spectrum of heart muscle disease (both familial and acquired), which they suggest offers an approach for differentiating overlapping mechanisms of myocardial inflammation.

This work demonstrates important new evidence for the role of detection of peripheral c-Met+ T cells in the diagnosis and monitoring of cardiac inflammation. It also offers avenues for novel therapies targeted at inhibiting c-Me to prevent cardiac autoimmunity proceeding to myocardial injury.

The study’s lead author was Interviewed for the BHF. During the interview Professor Marelli-Berg explained: “We think that this test for myocarditis could be a simple addition to the routine blood tests ordered in doctors’ surgeries. When viewed in combination with symptoms, the results could allow GPs to easily determine whether their patients have myocarditis.”

See the full study here:
https://www.ahajournals.org/doi/10.1161/CIRCULATIONAHA.121.055610