Heterogeneity of Checkpoint Inhibitor-Associated Pneumonitis: A Multicenter Study on Inflammatory Subtypes and...

Area of Science:

• Immunology
• Pulmonology
• Oncology

Background:

• Checkpoint inhibitor-associated pneumonitis (CIP) is a severe complication of tumor immunotherapy.
• T lymphocytes are the primary mediators of CIP.
• The heterogeneity of blood inflammatory profiles in CIP and its clinical impact are not well understood.

Purpose of the Study:

• To classify CIP based on peripheral blood immune cell percentages.
• To investigate the clinical characteristics and outcomes associated with different CIP subtypes.

Main Methods:

• A multicenter retrospective study involving 113 CIP patients without pathogen infection.
• Classification of CIP into subtypes based on peripheral blood immune cell percentages.

Main Results:

• Three inflammatory subtypes were identified: normal (42.5%), neutrophil (41.6%), and eosinophil (15.9%).
• Neutrophil-type CIP was linked to symptomatic onset, specific radiological patterns, higher steroid and anti-fibrotic treatment needs, and a 27.7% mortality rate.
• Eosinophil-type CIP was associated with chronic pulmonary inflammation, specific radiological features, and a better prognosis.

Conclusions:

• CIP can be categorized into normal, neutrophil, and eosinophil types with distinct clinical trajectories.
• Subtype-specific treatment strategies are crucial for managing CIP.
• Early intervention in normal and eosinophil subtypes may improve patient outcomes.