Increased plasma type B natriuretic peptide in the acute phase of Kawasaki disease

Background: The aim of this study was to identify possible factors associated with type-B natriuretic peptide (BNP) production in the acute phase of Kawasaki disease (KD). Methods: Subjects were 54 patients with KD (KD group [KDG]) and 18 age-matched controls (control group [CG]). We evaluated left ventricular function using multi-modal echocardiography and determined blood chemistry including BNP, white blood cell count, C-reactive protein (CRP), and interleukin (IL)-6 in the KDG. We compared echocardiographic parameters between the KDG and the CG and determined the correlation between log (BNP) and echocardiographic parameters, white blood cell count, CRP, and IL-6 in the KDG. Results: The KDG showed high BNP (169.6 +/- 529.6 pg/ml) despite preserved left ventricular function indicated by no significant difference in left ventricular ejection fraction (72.2 +/- 9.2 vs 71.2 +/- 7.8 %), z-score of left ventricular diastolic dimension (0.8 +/- 1.3 vs 0.9 +/- 0.8 SD), and Tei index (0.29 +/- 0.09 vs 0.30 +/- 0.06) between the KDG and the CG. However, left ventricular ejection fraction (r = -0.44, P = .001) and left ventricular end-diastolic dimension (r = 0.30, P < .05) significantly correlated with log (BNP). On the other hand, the KDG showed high CRP (89.7 +/- 55.6 mg/l) and high IL-6 (242.2 +/- 243.5 pg/ml), and CRP (r = 0.60, P < 0.0001) and IL-6 (r = 0.78, P < 0.0001) significantly correlated with log (BNP). Multiple stepwise regression analysis identified IL-6 (r = 0.77, P < 0.0001) most significantly correlated with log (BNP). Conclusions: In acute KD, BNP significantly increases, despite well-preserved global left ventricular function, and inflammation might be associated with this increased BNP.