Early decreased plasma levels of factor B and C5a are important biomarkers in children with Kawasaki disease.
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.


CONCLUSIONS
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.
Department of Cardiovascular Diseases, Children's Hospital Affiliated to Capital Institute of Pediatrics, Beijing, China.
Qing-Mei
QM
Zou
Department of Cardiovascular Diseases, Children's Hospital Affiliated to Capital Institute of Pediatrics, Beijing, China.
Xiao-Hui
XH
Li
Department of Cardiovascular Diseases, Children's Hospital Affiliated to Capital Institute of Pediatrics, Beijing, China.
Rui-Xia
RX
Song
Department of Emergency, Children's Hospital of Jiangxi Province, Nanchang, Jiangxi, China.
Nan-Ping
NP
Xu
Central Laboratory of Infection and Immunity, Capital Institute of Pediatrics, Beijing, China.
Ting
T
Zhang
Department of Cardiovascular Diseases, Children's Hospital Affiliated to Capital Institute of Pediatrics, Beijing, China.
Ming-Ming
MM
Zhang
Department of Cardiovascular Diseases, Children's Hospital Affiliated to Capital Institute of Pediatrics, Beijing, China.
Yao
Y
Lin
Department of Cardiovascular Diseases, Children's Hospital Affiliated to Capital Institute of Pediatrics, Beijing, China.
Lin
L
Shi
Clinical Center Laboratory, Capital Institute of Pediatrics, Beijing, China.
Jin
J
Fu
Clinical Center Laboratory, Capital Institute of Pediatrics, Beijing, China.
Xiao-Dai
XD
Cui
D015415:Biomarkers / Q000097:blood*; D002648:Child; D015936:Complement C5a / Q000378:metabolism*; D011415:Complement Factor B / Q000378:metabolism*; D006801:Humans; D009080:Mucocutaneous Lymph Node Syndrome / Q000097:blood*
D015415:Biomarkers; D015936:Complement C5a; D011415:Complement Factor B