C-reactive protein and N-terminal pro-brain natriuretic peptide discrepancy: a differentiation of adenoviral pharyngoconjunctival fever from Kawasaki disease

PURPOSE: To differentiate adenoviral pharyngoconjunctival fever (PCF) from acute Kawasaki disease (KD) using laboratory tests before results of virus-real time polymerase chain reaction and ophthalmologic examination are obtained. METHODS: Baseline patient characteristics and laboratory measurements were compared between 40 patients with adenovirus infection and 123 patients with KD. RESULTS: The patients with adenovirus infection were generally older than those with KD (median: 3.9 years vs. 2 years, P=0.000). White blood cell and, platelet count, and aspartate aminotransferase, alanine aminotransferase, and N-terminal pro-brain natriuretic peptide (NT-proBNP) levels showed significant differences between the 2 groups, but the C-reactive protein (CRP) levels did not (6.8±3.0 mg/dL vs. 8.3±5.8 mg/dL, P=0.126). In the adenovirus infection group, the CRP levels were <1, <3, <10, and ≥10 mg/dL in 2 (5%), 3 (7.5%), 30 (75%), and 5 patients (12.5%), respectively. The cutoff NT-proBNP level was 265 pg/mL. Discrepancy was defined as CRP and NT-proBNP levels of ≥3 or <3 mg/dL, and <265 or ≥265 pg/mL, respectively. Among the 35 patients with adenovirus infection whose CRP levels were ≥3 mg/dL, 29 (82.9%) showed a discrepancy. Conversely, of the 103 patients with KD whose CRP levels were ≥3 mg/dL, 83 (80.6%) showed no discrepancy. Between the groups, a significant difference in discrepancy rate was observed (P=0.000). None of the patients with adenovirus infection had CRP and NT-proBNP levels of <3 mg/dL and ≥265 pg/mL, respectively. CONCLUSION: With a sensitivity of 82.9% and a specificity of 80.6%, CRP and NT-proBNP levels may differentiate between adenoviral PCF and acute KD.