Inflammatory Cell Profiles in Early- and Late-Manifestation Immune Checkpoint Inhibitor Myocarditis
Authors' conclusion
Late-manifestation ICI myocarditis may represent a temporally distinct or partially attenuated inflammatory phase. Despite a milder inflammatory profile, higher cancer-related mortality was observed
Study context
- Population
- Patients diagnosed with myocarditis after immune checkpoint inhibitor (ICI) initiation who underwent endomyocardial biopsy
- Participants
- 35 patients
- Exposure
- Early- vs late-manifestation ICI myocarditis
- Early-manifestationn = 26
- Late-manifestationn = 9reference
Methodological detailsnational
- National
Main finding
As reported in the abstract
Myocardial inflammatory cell infiltration on endomyocardial biopsy
| Group | CD3+ T cells | CD8+ T cells | CD 68+ macrophages |
|---|---|---|---|
| Early-manifestation | 432 [173-1,381] | 289 [73-994] | 307 [116-841] |
| Late-manifestation | 121 [43-400] | 86 [21-168] | 57 [36-200] |
CD3+ T cells
Early-manifestation432 [173-1,381]
Late-manifestation121 [43-400]
CD8+ T cells
Early-manifestation289 [73-994]
Late-manifestation86 [21-168]
CD 68+ macrophages
Early-manifestation307 [116-841]
Late-manifestation57 [36-200]
- Early-manifestation vs Late-manifestation: P = 0.036 — CD3+ T cells
- Early-manifestation vs Late-manifestation: P = 0.019 — CD8+ T cells
- Early-manifestation vs Late-manifestation: P = 0.008 — CD 68+ macrophages
- Early-manifestation vs Late-manifestation: P = 0.054 — CD4+ T cells, higher in early, not significant
Observational data: associations, not effects.
Further findings
Events
| Outcome | Early-manifestation | Late-manifestation |
|---|---|---|
| Myocarditis mortality | 2 | 0 |
| Cancer-related mortality | 2 | 3 |
Clinical features
- Early-manifestation: higher cardiac biomarker levels and older age
- LVEF similar between groups
ICI reinitiation
- ICI therapy reinitiated in patients overall
- 2
Original publication
Inflammatory Cell Profiles in Early- and Late-Manifestation Immune Checkpoint Inhibitor Myocarditis. JACC CardioOncol. Published 30 July 2026. doi:10.
Summarised from the published abstract; every number is checked against it