B-type natriuretic peptide in predicting the severity of community-acquired pneumonia

摘要

BACKGROUND: Although pneumonia severity index(PSI) is widely used to evaluate the severity of community-acquired pneumonia(CAP), the calculation of PSI is very complicated. The present study aimed to evaluate the role of B-type natriuretic peptide(BNP) in predicting the severity of CAP.METHODS: For 202 patients with CAP admitted to the emergency department, BNP levels, cardiac load indexes, inf lammatory indexes including C-reactive protein(CRP), white blood cell count(WBC), and PSI were detected. The correlation between the indexes and PSI was investigated. BNP levels for survivor and non-survivor groups were compared, and a receiver operating characteristic(ROC) curve analysis was performed on the BNP levels versus PSI.RESULTS: The BNP levels increased with CAP severity(r=0.782, P<0.001). The BNP levels of the high-risk group(PSI classes IV and V) were signifi cantly higher than those of the low-risk group(PSI classes I–III)(P<0.001). The BNP levels were signifi cantly higher in the non-survivor group than in the survivor group(P<0.001). In addition, there were positive correlations between BNP levels and PSI scores(r=0.782, P<0.001). The BNP level was highly accurate in predicting the severity of CAP(AUC=0.952). The optimal cut-off point of BNP level for distinguishing high-risk patients from low-risk ones was 125.0 pg/m L, with a sensitivity of 0.891 and a specifi city of 0.946. Moreover, BNP level was accurate in predicting mortality(AUC=0.823). Its optimal cut-off point for predicting death was 299.0 pg/m L, with a sensitivity of 0.675 and a specifi city of 0.816. Its negative predictive cut-off value was 0.926, and the positive predictive cut-off value was 0.426.CONCLUSION: BNP level is positively correlated with the severity of CAP, and may be used as a biomarker for evaluating the severity of CAP.