N末端脑利钠肽原在川崎病患儿中的变化及其意义

Change in plasma N-terminal pro-brain natriuretic peptide in children with Kawasaki disease and its value in clinical practice

目的探讨N末端脑利钠肽原(N-terminalpro-brainnatriureticpeptide,NT-proBNP)在川崎病(Kawasakidisease,KD)患儿中的变化及其临床意义。方法分别测定13例确诊为KD患儿急性期的血浆NT-proBNP水平,并测定了其中的8例恢复期患儿血浆NT-proBNP水平,同时以9例小儿上呼吸道感染急性期为对照组的血浆NT-proBNP水平。分别测定KD患儿在急性期及恢复期的外周血白细胞计数(whitebloodcell,WBC)、C反应蛋白(C-reactiveprotein,CRP)及血浆心肌肌钙蛋白(cardiactroponinI,cTnI)水平,常规超声心动图检测左心室舒张末期内径(leftventricularenddiastolicdiameter,LVDd)、射血分数(leftventricularejectionfraction,LVEF)、舒张期二尖瓣血流频谱速度及冠状动脉病变情况。结果KD患儿急性期血浆NT-proBNP水平为(691±86)ng/L,而对照组小儿血浆中NT-proBNP水平为(47±10)ng/L,两组相比差异具有统计学意义(P<0·001)。有8例KD患儿同时测定了急性期及恢复期血浆NT-proBNP水平。急性期患儿血浆NT-proBNP水平为(636±89)ng/L,在恢复期血浆NT-proBNP水平显著降低,为(164±35)ng/L(P<0·01)。通过直线回归分析,KD患儿急性期血浆NT-proBNP水平与左心室EF、LVDd均无相关关系,同时与患儿舒张期二尖瓣血流频谱E峰及A峰比值也无相关关系。但是,KD患儿急性期血浆NT-proBNP水平与患儿急性期CRP、WBC呈显著正相关(r分别为0·615及0·547,均P<0·05),同时还与急性期患儿的心肌肌钙蛋白水平呈显著正相关(r=0·611,P<0·05)。结论血浆NT-proBNP水平在KD急性期显著升高,而在疾病恢复期其水平明显降低。KD患儿急性期血浆NT-proBNP水平的升高可能与急性期KD患儿的心肌炎症及炎性因子的升高有关。

Objective Brain natriuretic peptide （BNP） is a cardiac hormone and its plasma level increases in congestive heart failure and myocarditis. An increased level of serum BNP has been reported in children in the acute stage of Kawasaki disease （KD）. But the mechanism of increased level of BNP in children with KD has not been elucidated and the change in BNP in children with KD in China has not been reported. The aim of this study was to investigate the change in plasma N-terminal pro-brain natriuretic peptide （ NT-pro BNP） in children with KD, examine the value of NT-pro BNP in the diagnosis of KD and explore the mechanism of the change in plasma NT-pro BNP in children with KD. Methods Thirteen patients, aged from 4 months to 56 months, with KD were enrolled and nine patients with acute upper respiratory infection were used as controls. Blood sample was obtained to measure plasma NT-pro BNP concentrations in the acute （n = 13） and convalescent （n =8） phases of KD and in the acute phase of the control patients. Plasma NT-pro BNP was measured using enzyme immunoassay. Other laboratory data including complete blood cell count, C-reactive protein, etc, were also measured in acute phase in both groups. The serum cardiac troponin I was also detected in acute phase of children with KD. All patients with KD had complete echocardiographic study, including measurement of left ventricular end diastolic diameter （LVDd）, left ventricular ejection fraction （LVEF） and left ventricular inflow velocity through the mitral annulus （including E-velocity and A-velocity）. Two dimensional echocardiography was performed to check for coronary lesions of patients with KD. The correlation between plasma NT-pro BNP and the above parameters was analyzed. Results The mean plasma NT-pro BNP concentration in patients with KD in the acute phase was（691±86） ng/L, and it was （47 ± 10） ng/L in patients of control group. The plasma NTpro BNP in patients with KD in the acute phase was significantly higher than that of the control group （ P 〈 0. 001 ）. In 8 cases of KD, the plasma NT-pro BNP concentrations were measured both in the acute and convalescent phase. The mean plasma NT-pro BNP concentration in the acute phase of KD was （636 ± 89 ） ng/L and it was （ 164 ± 35 ） ng/L in the convalescent phase. The level of plasma NT-pro BNP decreased significantly in the convalescent phase （ P 〈 0. 01 ）. Through linear regression analysis, there was no significant correlation between the plasma concentrations of NT-pro BNP in acute phase of KD and LVEF, LVDd and E/A ratio, respectively. But the NT-pro BNP level correlated positively with C-reactive protein and white blood cells counts （ r =0. 615, P 〈 0. 05 and r = 0. 547, P 〈 0. 05 ）, respectively. NT-pro BNP level correlated positively with serum cTnI, a sensitive biologic marker of cardiac injury （r = 0. 611, P 〈 0. 05 ）. Conclusion The plasma NT-pro BNP concentration increased in the acute phase and decreased significantly in the convalescent phase of KD. The plasma NT-pro BNP might be one of the useful biological markers of KD, and the mechanism of change in plasma NT-pro BNP in KD might be associated with cardiac injury and inflammatory factors.