Single-cell landscape of bronchoalveolar immune cells in patients with immune checkpoint inhibitor-related pneumonitis

We conducted single-cell and T-cell receptor transcriptomic sequencing on the bronchoalveolar lavage fluid from five patients with grade ≥2 immune checkpoint inhibitor-related pneumonitis. Our analyses revealed a prominent enrichment of T cells in the bronchoalveolar lavage fluid of patients with immune checkpoint inhibitor-related pneumonitis. All enrolled patients in the prospective cohort underwent standard bronchoscopy under general anesthesia to collect BALF samples. Generally, the bronchoscope was guided to the ICP-affected lung lobe or segment, and preheated sterile saline was injected into the airway multiple times. A total of 30ml of lavage fluid was retrieved from each patient, with 5-10ml reserved for routine clinical tests and the remainder used for scRNA-seq.