Abstract: Objective To explore the relationship between serum levels of peptidylarginine deiminase (PAD) 2, nuclear factor-kappa B (NF-κB), heparin binding protein (HBP) and pulmonary infections, and the diagnosis value of their combined detection for pulmonary infections. Methods From 1 January 2020 to 30 January 2025, 84 patients with pulmonary infections in our hospital were recruited, and 30 non-infected hospitalized patients were set as control group. ELISA method was used to detect serum levels of PAD2 and NF-κB, and HBP level were detected by immunofluorescence. Pearson's correlation method was used to analyze the correlation between serum PAD2, NF-κB, HBP and white blood cell count (WBC), C-reactive protein, neutrophil percentage.. Logistic regression was used to analyze the influencing factors of lung infection. ROC curve was used to evaluate the usefulness of serum PAD2, NF-κB, and HBP for diagnosis of pulmonary infections. Results The serum levels of PAD2, NF-κB, and HBP of patients in the observation group were significantly higher than those in the control group (P<0.05). The serum levels of PAD2, NF-κB, HBP significantly correlated with the levels of white blood cell count (WBC), C-reactive protein and neutrophil percentage in observation group (P<0.05). Serum PAD2, NF-κB, and HBP were risk factors for pulmonary infection (P<0.05). The areas under the curve (AUC) of ROC of PAD2, NF-κB, HBP and combination for diagnosis of pulmonary infection were 0.814, 0.787, 0.804, and 0.930 respectively, and the diagnostic efficacy of the combined test was better (Z_combination=3.226, P<0.05). Conclusion Serum levels of PAD2, NF-κB, and HBP were closely related to pulmonary infections, and correlated with the levels of infection indicators, and the combination of these three factors displays a better diagnostic value for pulmonary infection.

Key words: Pulmonary infection, Peptidylarginine deiminase 2, Nuclear factor-kappa B, Heparin binding protein