Evaluation of B-type natriuretic peptide in patients with community acquired pneumonia

Background: Community acquired pneumonia (CAP) is a widespread disease, brain natriuretic peptide (BNP) shown to be elevated in patients with congestive heart failure, acute myocardial infarction and massive pulmonary embolism, BNP levels have been found to be significantly elevated in CAP with a positive correlation to CRP and also low levels of BNP predict treatment success. Objective: The aim of this study was to evaluate the utility of cardiac stress marker B-type natriuretic peptide in patients with CAP without sepsis or shock. Patients and methods: 26 patients with CAP were eligible for study in addition to 10 healthy control cases, cardiac stress marker BNP and inflammation marker (CRP, white blood cell count, ESR) were measured in patients with CAP. Results: The mean serum level of initial BNP level was significantly higher (86.75 ± 25.91 pg/ml) in patients with CAP than the control group (30.70 ± 6.77 pg/ml) with p-value <0.001 and also significantly lower after treatment (40.15 ± 9.60) with p-value <0.001, BNP significantly positively correlated with (CRP) in patients before treatment (r = 0.709, p < 0.001) and also positively correlated with CRP after treatment (r = 0.490, p = 0.011), there was significant negative correlation between initial BNP level and partial arterial oxygen pressure (r = −0.409, p = 0.038). The optimal cut-off for BNP was 47.0 pg/ml at admission vs 39.5 pg/ml after treatment. Conclusion: In this study BNP levels show a transient rise in patients with community acquired pneumonia and correlate well with CRP, low levels of BNP adequately identify patients with an uncomplicated disease course.