Abstract Body (Do not enter title and authors here):
Introduction
Clonal hematopoiesis of indeterminate potential (CHIP) was recently shown to be an independent risk factor for immune checkpoint inhibitor (ICI)-associated myocarditis. However, the mechanisms by which CHIP may contribute to immune dysregulation in this context remain poorly understood.

Research Questions
How does CHIP contribute to immune dysregulation in cancer patients receiving ICIs, and what cytokine-producing cell types and pathways drive CHIP-associated inflammation?

Methods
To investigate this, we implemented the CellChat framework to single-cell RNA sequencing (scRNA-seq) data in order to infer and compare cell-cell communication networks. We analyzed scRNA-seq data from six post-ICI myocarditis patients, three of whom were CHIP-positive and three CHIP-negative from Yale. Using CellChat, we constructed condition-specific intercellular signaling networks and compared overall signaling activity, communication strength, and pathway usage across groups. We further validated the findings with two other cell-cell interaction analysis tools, DominoSignal and CellPhoneDB.

Results
CHIP-positive samples exhibited a higher number (3440 vs 2466 CHIP vs no CHIP) and strength of ligand-receptor interactions compared to CHIP-negative samples (110 vs 75, CHIP vs no CHIP), indicating globally elevated intercellular signaling (Figure 1). Network and heatmap visualizations revealed increased cell-cell communication in CHIP positive patients compared to CHIP negative patients particularly among immune cell types, including monocytes, platelets, plasmacytoid dendritic cells, and naive B cells.
Directional analysis showed enhanced outgoing signals from naive B cells and increased incoming signals to macrophages and plasmacytoid dendritic cells in CHIP-positive samples. Of note, increased platelet interactions with native CD4 and CD8 T cells were noted. Pathway-level analysis highlighted upregulation of pro-inflammatory and pro-platelet activation signaling, including TNF, CXCL, CD30, and CD40 (Figure 2).

Conclusion
These findings suggest that CHIP is associated with a pro-inflammatory signaling environment that contributes to ICI myocarditis. These findings support its potential as a biomarker for risk stratification and as a target for pathway-specific anti-inflammatory therapies. For future directions, these results will be validated with external ICI myocarditis cohorts.