Can B-Type Natriuretic Peptide (BNP) be a Predictor of Severity and Outcome of Community-Acquired Pneumonia (CAP)? A Prospective Follow-Up Study.

Tropical India holds about 23% of the global pneumonia burden with case fatalities ranging between 15 to 30%, with CAP being one of the prominent causes of morbidity and mortality among adults. BNP, a hormone from ventricular myocytes during myocardial stretch or stress, causes vasodilation and natriuresis. Perhaps established as an efficient biomarker in cardiac illnesses, the possibility of it being a predictor of severity and mortality in CAP is studied. Material: 175 participants with CAP were included in the study excluding anemia and cardiac/ renal/ hepatic morbidities. Clinical history and examination, BNP, CRP, ESR, TLC, CRB-65 scores were elucidated at the time of presentation and after two weeks. Observation: At presentation, the mean values of BNP, CRP, ESR, and TLC values at presentation were 189.59, 137.29, 69.31, and 18.53* 103, whereas after two weeks of treatment, they were 94.08, 43.21, 33.01, 11.14 respectively all being significant (p <0.05). 41 participants had a CRB-65 score of one (mean BNP of 149.68), whereas rest 34 had more than one (mean BNP of 229.51). The BNP levels correlated positively with CRP, and ESR both at baseline (r=0.62, p< 0.05; r= 0.74, p< 0.05) and after treatment (r=0.39, p< 0.05; r= 0.56, p< 0.05) Conclusion: Gauging BNP levels at admission is a rapid and reliable means to triage CAP pneumonia patients into various levels of care. BNP correlates well with other biomarkers and CRB-65 scores and thus the clinical severity and outcome of CAP.