Natriuretic peptide as an adjunctive diagnostic test in the acute phase of Kawasaki disease.

Coronary arteritis rather than myocardial involvement is typically emphasized in Kawasaki disease (KD). Moreover, the criteria and the usual biological markers oversee the importance of cardiac-specific markers in diagnosing this disease. We sought to study the clinical usefulness of measuring B-type natriuretic peptide (BNP) and its N-terminal moiety (NT-proBNP) at the onset of KD. Our objective was to evaluate blood concentrations of BNP and NT-proBNP during the acute and subacute phases of KD. We conducted a prospective study comparing newly diagnosed KD patients to non-KD febrile controls. Blood specimens were collected at presentation, 6-12 h after intravenous immunoglobulin (IVIG) therapy, 1-2 weeks later, and 2-3 months later, or only upon reenrollment for controls. Forty-there KD and 19 control patients were enrolled consecutively. The mean age was 47.1 +/- 34.3 and 62.2 +/- 44.9 months, respectively (p = NS). Pre-IVIG NT-proBNP levels were significantly higher in KD patients than in controls (923.6 +/- 1361.7 vs. 186.2 +/- 198.0 ng/L; p < 0.001), with no statistical difference for BNP (141.9 +/- 227.5 vs. 59.9 +/- 72.4 ng/L; p = 0.112). In conclusion, our data indicate that NT-proBNP is a better marker of myocardial involvement in acute KD than BNP, particularly in cases with incomplete diagnostic criteria, and suggest that it may be a valid adjunctive diagnostic method to support the diagnosis of KD.