Prospective Study of NMR-based Serum Metabolic Profiles for the Diagnosis of Checkpoint Inhibitor-related Pneumonitis

Checkpoint inhibitor-related pneumonitis (CIP) is a common and potentially fatal immune-related adverse event associated with PD-1/PD-L1 inhibitor therapy. The early and accurate diagnosis of CIP is crucial for timely intervention and improving patient prognosis. However, in clinical practice, the overlapping clinical presentations and imaging features of CIP with infectious pneumonia, tumor progression, or other pulmonary diseases pose a significant diagnostic challenge. The current lack of precise and specific diagnostic techniques often leads to underdiagnosis or misdiagnosis. This diagnostic dilemma can delay the optimal treatment window and may result in the unnecessary interruption or discontinuation of effective immunotherapy, ultimately compromising overall anti-tumor efficacy.

Metabolomics, the comprehensive analysis of small-molecule metabolites, provides a dynamic readout of an organism's physiological state and has shown great promise in biomarker discovery for various diseases. Serum, in particular, offers an easily accessible biofluid that reflects systemic metabolic alterations. ¹H-Nuclear Magnetic Resonance (¹H-NMR) spectroscopy is a robust, reproducible, and quantitative platform ideal for profiling key serum components, including lipoproteins and a wide range of low-molecular-weight metabolites, in a high-throughput manner. The investigators hypothesize that the development of CIP induces a distinct, detectable alteration in the host's systemic metabolic profile, which can be captured by NMR analysis and serve as a diagnostic signature.