Background: Echocardiography remains the cornerstone of diagnosis of cardiac complications in patients with Kawasaki disease (KD), and is also useful for the diagnosis of incomplete KD (i-KD). Since echocardiographic evaluation is based on somewhat subjective assessment by pediatric cardiologists, objective diagnostic measures by which general pediatricians can screen high-risk patients or make diagnosis of i-KD are desired.
Objective: To assess D-dimer and fibrinogen degradation products (FDP) as possible markers of coronary vascular damage in KD patients.
Design/Methods: Between June 2008 and March 2014, we recruited 121 KD patients: 86 with complete KD (c-KD) treated with intravenous immunoglobulin (IVIG), 10 with c-KD treated only with aspirin (a-KD), 16 with i-KD fulfilling four major criteria, and seven with severe refractory KD (s-KD). Control patients included five with Henoch-Schonlein purpura (HSP), 15 with fibrile convulsion (FC), and 39 with pneumonia. We retrospectively checked their medical records, echocardiography, and blood test results on admission and after IVIG therapy.
Results: Peak D-dimer values (normal range < 1.0 μg/ml) were significantly higher in c-KD (2.9±2.4) than in a-KD (1.1±0.7), FC (0.8±0.4) and pneumonia (1.3±1.1) groups (p < 0.05). Peak FDP value in the c-KD group was 6.8±4.7 μg/ml (< 5.0). Peak D-dimer and FDP values were the highest in the HSP group, followed by the s-KD group, and were comparable between the i-KD and c-KD groups. D-dimer values (2.9±1.4) at post IVIG were higher than those on admission (1.8±1.1) (p < 0.0001), while there was no significant change in FDP values. There was no significant difference in D-dimer or FDP values between KD with cardiac finding(s) and without. WBC and CRP values had no correlation with those of FDP or D-dimer.
Receiver operating characteristic analysis determined a cut-off value of 1.1 μg/ml for D-dimer for c-KD, with the area under the curve (AUC) 0.85, sensitivity 0.95, specificity 0.59 and probability 0.44. Similarly, a cut-off value for FDP was determined as 2.5 μg/ml with AUC 0.90, sensitivity 0.89, specificity 0.70 and probability 0.40.
Conclusions: Elevated D-dimer and FDP values help assist diagnosis of i-KD, but cannot predict cardiac complications in KD patients.