To assess the diagnostic efficacy of serum heparin-binding protein (HBP) as a standalone biomarker and in combination panels for distinguishing early-stage bacterial from viral pneumonia, and to explore its prognostic value in predicting progression to severe pneumonia. This retrospective cohort study enrolled 269 participants, including 166 bacterial pneumonia patients (BPG), 42 viral pneumonia patients (VPG), and 61 age-/sex-matched healthy controls (NCG). Serum concentrations of four inflammatory biomarkers—HBP, procalcitonin (PCT), serum amyloid A (SAA), and C-reactive protein (CRP)—were quantitatively analyzed in all participants using immunoturbidimetry assays. Comparative analysis of inflammatory marker levels among the three groups was conducted, and receiver operating characteristic (ROC) curve analysis was employed to evaluate the diagnostic performance of these four inflammatory biomarkers for distinguishing bacterial from viral pneumonia. Patients were stratified into mild and severe pneumonia groups based on CURB-65 score, followed by binary logistic regression and forest plot analysis to identify factors associated with disease severity. Serum levels of HBP, SAA, and CRP were significantly elevated in both BPG and VPG compared with the NCG ( P < 0.01). PCT concentrations showed marked elevation exclusively in bacterial pneumonia ( P < 0.01), while remaining comparable to CPG in VPG ( P = 0.47). The four inflammatory biomarkers demonstrated favorable diagnostic performance for differentiating both bacterial and viral pneumonia, with enhanced diagnostic accuracy observed in bacterial cases. Notably, HBP exhibited the most prominent discriminative capacity (optimal cutoff: 17.9 ng/mL; AUC: 0.93, 95% CI 0.89–0.97; sensitivity: 81.93%; specificity: 96.72%). The biomarker combination strategy integrating HBP with other three indicators significantly improved diagnostic efficacy. Multivariate binary logistic regression coupled with forest plot analysis identified serum HBP as an independent predictor of severe bacterial pneumonia. HBP emerges as a dual-functional biomarker demonstrating diagnostic precision for early-stage bacterial pneumonia and prognostic capability for disease progression. Compared to a single biomarker, the combined detection of HBP, PCT, SAA and CRP is more valuable for diagnosing bacterial pneumonia.
Cao et al. (Sat,) studied this question.