Predictive Value of Lymphocyte Count Changes on Checkpoint-inhibitor-related Pneumonitis in Patients with Non-small Cell Lung Cancer

Objective To investigate the correlation of peripheral blood lymphocyte, T-cell, Th-cell, and Ts-cell counts with the development of checkpoint-inhibitor-related pneumonitis in NSCLC.

Methods The clinical data of 85 patients with NSCLC treated with immune checkpoint inhibitors (ICIs) were retrospectively analyzed.Paired t-test was used to analyze lymphocyte changes.ROC curves were utilized to analyze predictive performance.The Spearman correlation coefficient test was conducted to analyze the linear relationship between lymphocyte changes and CIP grade.

Results A statistically significant decrease in lymphocyte, T-cell, Th-cell, and Ts-cell counts from the baseline was observed in patients at the onset of CIP (P < 0.05), whereas no such change was observed in the control group.ROC curve analysis revealed AUCs of 0.867, 0.843, 0.865, and 0.843 for lymphocyte, T-cell, Th-cell, and Ts-cell counts, respectively.A linear relationship was found between the percentage decrease in lymphocyte, T-cell, and Ts-cell counts from the baseline and the severity of CIP (P < 0.05).

Conclusion Decreased lymphocyte, T-cell, Th-cell, and Ts-cell counts have a predictive value for the development of CIP, and the lymphocyte count change has the greatest predictive value.The percentage decrease in lymphocyte, T-cell, and Ts-cell counts from the baseline is correlated with the severity of CIP.