N-terminal pro-brain natriuretic peptide as a useful diagnostic marker of acute Kawasaki disease in children

Abstract

Background: Serum N-terminal pro-brain natriuretic peptide (NTproBNP) is often elevated in patients with acute Kawasaki disease (KD), but the NTproBNP level in normal children is higher than in adults. Thus, characterization of the normal levels and cut-off values of NTproBNP according to age is warranted for proper diagnosis of acute KD in children. Methods and Results: Six hundred and fifty-five patients aged 1 month-15 years (median, 2.9 years) were included. Patients were admitted to the NTT East Japan Sapporo Hospital between October 2007 and October 2011. Serum NTproBNP level was examined in 149 patients with KD (median, 2.1 years) and 506 control patients with acute infectious disease (median, 3.2 years). In the control group, a Z-score curve of NTproBNP was generated for each age group using least mean square-based methods. The Z-score distribution of KD patients was then compared with that of the control group. The specificity and sensitivity of NTproBNP for diagnosing acute KD were 97.8% and 47.0%, respectively, at Z-score >2.0. Additionally, simple cut-offs every 100 pg/ml according to age were established for more convenient use at the bedside. Conclusions: The Z-score curve for NTproBNP in children was characterized. A Z-score >2.0 or the cut-off for children may be used to diagnose acute KD.