Abstract: Objective　To investigate the changes of platelet surface expression of glycoprotein Ⅱb/Ⅲa fibrinogen receptor (PAC-1) in Kawasaki disease (KD) patients at different phases, and to analyze the correlation between PAC-1 and coronary artery lesion in KD. Method　A total of 27 hospitalized children with KD from March to September 2016 were selected as study subjects, and fever control group (36 cases) and healthy control group (40 cases) were set at the same time. KD children were further divided into coronary artery injury (CAL) group and non-coronary artery injury (NCAL) group according to echocardiography. Peripheral venous blood was collected in each group and the expression of PAC-1 was detected by flow cytometry. Results　The platelet expression levels of PAC-1 in children with KD in the acute, subacute, and convalescent stages were significantly different from those in the fever and healthy control groups (P<0.001), with the lowest expression levels in the healthy control group. The expression of PAC-1 in KD children was the highest in subacute stage, followed by acute stage and convalescence stage. The expression of PAC-1 in CAL group in subacute phase was significantly higher than that of NCAL group, and the difference was statistically significant (P<0.05). Conclusion　The expression levels of platelet PAC-1 were increased throughout the course of the disease in children with KD, indicating the presence of platelet activation. The expression levels of PAC-1 were significantly increased in the subacute phase of KD children, and were significantly higher in the CAL group than in the NCAL subgroup, suggesting that platelet activation was associated with KD coronary artery injury.

Key words: Kawasaki disease;　platelet surface expression of glycoprotein Ⅱb/Ⅲa fibrinogen receptor;　platelet activation;　coronary artery lesion