Background: This study investigated prognostic factors for early recovery of coronary artery lesion (CAL) in children with Kawasaki disease (KD). Methods: Patients hospitalized for KD were enrolled less than 2 wk from the onset of illness and divided into two groups: KD with CAL and KD without CAL. The CAL group was further divided into two subgroups according to the degree of CAL: mild (n = 31) and moderate/severe (n = 6) and further divided into two subgroups according to the age: younger than 1 y (n = 9) and older than 1 y (n = 28). Lectin pathway-related factors MASP-1, CD59, and C5b-9 were measured, along with C-reactive protein, white blood cell counts, erythrocyte sedimentation rate, and platelet count. Patients were followed up for 3 mo. Correlation between the measured factors and the length of time of recovery from CAL was analyzed. results: Plasma concentrations of MASP-1 in the CAL group were significantly lower than those without CAL. MASP-1 and gender positively correlated with the recovery time of CAL. There was no difference in MASP-1 between mild and moderate/severe CAL. At 3-mo follow-up, there was a positive correlation between plasma MASP-1 concentration and recovery time of the patients with CAL older than 1 y. conclusion: Plasma MASP-1 concentration at the early stage of KD is predictive of length of time of recovery from CAL. k awasaki disease (KD), also known as mucocutaneous lymph node syndrome, is an acute nonspecific systemic vascular inflammatory syndrome occurring mainly in children under 5 y of age. A considerable volume of research has shown that the pathological process of KD is characterized by immune activation and immune vasculitis of the vascular endothelial cells (1). KD mostly affects the small and mediumsized arteries, especially the coronary artery (2), resulting in coronary artery lesion (CAL), such as dilation, aneurysm formation, or advanced stenosis, and it is the leading cause of death in children with KD (3). It has been reported that 15-25% of untreated KD patients may develop CAL (4). Although treatment with intravenous immunoglobulin within 10 d of onset of fever reduces the incidence of CAL, 5-8% of patients still develop it. The degree of CAL varies considerably between individuals, ranging from mild to moderate ectasia of the coronary artery to giant aneurysm formation. The recovery time of CAL also differs between patients. There is a very little information about the length of time for which different degrees of CAL persists. Little is known on the relationship between the complement system and the recovery time of CAL resulting from KD. Our previous study indicated that the lectin pathway of the complement system is activated in KD. CAL is associated with endothelial cell dysfunction induced by T-cell activation (5). Endothelial cells are a source of complement-related factors and complement regulatory factors (6), and MASP-1 activates endothelial cells directly, which then activates the complement lectin pathway (7). Endothelial cell dysfunction (8) and com...

Background:The mechanisms underpinning Kawasaki disease (KD) are incompletely understood. There is an unmet need for specific biomarkers for the early diagnosis of KD. Methods: Eighty-five KD patients suffering from acute-phase and subacute-phase KD, 40 healthy children, and 40 febrile children comprised the study cohort. An enzyme-linked immunosorbent assay was used to measure plasma levels of C1q, C1q-circulating immune complex (C1q-CIC), mannan-binding lectin-associated serine protease (MASP)-1, factor B, C4d, C3d, C5a, C5b-9 and CD59. results: Plasma concentrations of factor B and C5a in the acute phase were lower than those in healthy and febrile control groups (all P < 0.05). Compared with acute-phase KD patients, plasma concentrations of C1q, factor B, and C3d in KD patients were increased significantly (P < 0.05), but those of C4d, MASP-1 and CD59 decreased significantly (P < 0.05), in patients with sub-acute KD. conclusion: These data suggest that more than one pathway in the complement system is activated in KD. Importantly, decreased plasma concentrations of factor B and C5a in the acute phase (6-10 d) could be employed as biomarkers for the early diagnosis of KD. k awasaki disease (KD) is an acute, self-limiting, nonspecific systemic vascular inflammatory syndrome. KD is considered to be caused by infectious agents in genetically susceptible children. The diagnosis of KD is dependent upon clinical manifestations; definitive diagnostic markers are lacking. The pathogenesis of KD is characterized by immune injury to endothelial cells (1) that results in systemic vasculitis or aneurysms in coronary arteries (2).Vascular endothelial cells are a source of complement and complement regulatory factors. Activated complement can form complement fragments (e.g., C3, C4d, Bb) and the membrane attack complex (MAC) on the cell surface (3). The MAC can mediate the inflammatory response by killing anucleate cells and bacteria, as well as causing cells to secrete a large number of cytokines and growth factors (4). Animal studies have shown that coronary atherosclerotic lesions appear not only during complement activation, but also during complement deposition, which results in tissue injury (5). It also has been demonstrated that complement components are accumulated in cryoglobulinemic vasculitis (6). Other studies have reported dysfunction of vascular endothelial cells (7) and the classical pathway of complement activation in all three layers of aneurysms (8).With the evidence stated above, we speculated that activation of the complement system might be involved in the pathogenesis of KD, and that activated complement factors could be employed as early diagnostic markers for KD. To test this hypothesis, we investigated plasma levels of various complement components in children with acute KD and subacute KD. RESULTS Changes in Plasma Concentrations of Complement FactorsC1q and C1q-circulating immune complex (C1q-CIC). C1q is a factor of the classical pathway of complement activation. The plasma level of C1q was sig...