Heart failure & cardiomyopathiesCohort study
Novel insights into the histopathological characteristics of immune checkpoint inhibitor-related myocarditis
- multicentre retrospective observational study
Authors' conclusion
Pathological grading using both global and hotspot assessment is valuable for the diagnosis and risk stratification of ICI-related myocarditis. As low-grade inflammation is not uncommon, supplementary markers such as HLA-DR, granzyme B, tenascin C, and PD-L1 may aid diagnosis. Furthermore, ICI-mediated NILVD may encompass cases of low-grade myocarditis.
Study context
- Population
- Patients diagnosed with or suspected of having immune checkpoint inhibitor (ICI)-related myocarditispatients diagnosed with or suspected of having ICI-related myocarditis
- Participants
- 38 patients
- Exposure
- Pathological grading (Palaskas et al.) with global vs hotspot assessment of lymphocyte infiltration
Main finding
As reported in the abstract
- Increased infiltration of CD3, CD4, CD8-positive T cells, and CD68 and CD163-positive macrophages with higher pathological grades
Observational data: associations, not effects.
Further findings
Inflammatory markers
- HLA-DR and tenascin C (clone 4F10) were sensitive markers of inflammation
- PD-L1 and tenascin C (clone 4C8) were more specific for high-grade inflammation
Prediction of myocarditis-related mortality, fulminant myocarditis and major adverse cardiac events
- Global assessment more accurately predicted myocarditis-related mortality than hotspot assessment
- Both methods similarly predicted fulminant myocarditis and major adverse cardiac events
Suspected ICI-mediated non-inflammatory left ventricular dysfunction (NILVD)
- Patients with suspected ICI-mediated NILVD, with minimal myocardial inflammation
- Two patients
Original publication
Summarised from the published abstract; every number is checked against it