OBJECTIVEKawasaki disease (KD) complicated with coronary artery lesion (CAL) seriously threatens survival quality and life of patients, suggesting that it is very important to early predict the risk of CAL and to early diagnose the disease. Nevertheless, up to now there has been no specific clinical biochemical marker for it because of the poor understanding of the pathological process of KD with CAL. Matrix metalloproteinases (MMPs) and their specific tissue inhibitor of metalloproteinases (TIMPs) play an important role in arterial wall extracellular matrix breakdown and remodeling and are involved in CAL in other diseases. In the present study the practical value of serum MMP-9 and TIMP-1 levels in the prediction and early diagnosis of CAL in KD patients was investigated.

METHODSAll subjects were from Chinese population. Serum levels of MMP-9 and TIMP-1 were measured by rapid one-step sandwich enzyme immunoassay in 59 KD patients including 15 with CAL and 44 without CAL by 2 D-echocardiography and coronary angiography, and 20 normal healthy children as controls. Blood samples of patients were obtained before and after intravenous immunoglobulin (IVIG) treatment in acute stage, subacute stage and convalescent stage as well. Serum MMP-9 and TIMP-1 levels and the ratio of MMP-9/TIMP-1 were compared by statistical method in KD patients and controls, as well as in KD with CAL and without CAL.

RESULTSIn acute stage serum MMP-9 and TIMP-1 levels and the ratio of MMP-9/TIMP-1 were higher (P < 0.01) in patients with KD than those in healthy children. After IVIG treatment in KD patients serum MMP-9 level and the ratio of MMP-9/TIMP-1 decreased (P < 0.01). Before IVIG treatment serum MMP-9 level and the ratio of MMP-9/TIMP-1 were higher (P < 0.01) in patients with CAL than those in patients without CAL, and in acute stage after IVIG treatment serum MMP-9 level of KD patients with CAL was still higher than that of KD patients without CAL.

CONCLUSIONIn acute stage of KD serum MMP-9 level and the ratio of MMP-9/TIMP-1 were higher in patients with CAL than those in patients without CAL, suggesting that during acute phase of KD the great increase in serum MMP-9 and the imbalance of the MMP-9/TIMP-1 ratio might be high risk factors of KD coronary artery lesion. Therefore, the measurement of serum MMP-9 and TIMP-1 might be of important clinical value in the prediction and the early diagnosis of KD with coronary artery lesion.