Kawasaki disease (KD) is an arteritis syndrome affecting young children. Numerous reports demonstrated pathological and immunological mechanisms of vascular injury in KD. Endothelial microparticles (EMPs) are intact vesicles resulting from exocytic budding of activated or apoptotic endothelial cells in response to vascular injury. EMPs may play a role in diagnosis or monitoring vasculitis in KD.
Objective: We attempted to characterize the level of EMPs in acute KD patients with different clinical severity.
Methods: Blood samples from patients with Kawasaki disease were collected in acute phase just before the initiation of intravenous immunoglobulin (IVIG) therapy. Fresh heparinized venous blood were collected at room temperature and processed within 6 hours. The samples were incubated and immunolabelled with annexin V, CD105, and CD62E before flow cytometric immunophenotyping. Demographic data and other standard laboratory studies were also collected.
Results: There were 12 cases of acute KD with age ranging from 3-72 months. Comparing to age-match healthy infant, the EMPs level was high in KD patients in the range of 18-390/mcL, especially higher in 3 IVIG-resistant cases. One patient with EMPs 99/mcL developed coronary artery ectasia. EMPs correlated well with clinical status and Kobayashi clinical severity scoring. However, ESR and CRP correlated poorly with EMPs.
Conclusion: Analysis of EMPs is a promising tool for assessing vascular injury in KD. The changes in the level of EMPs are more promptly reflecting the clinical status as compared to the conventional inflammatory markers.