[Matrix metalloproteinase-1 expression in the circulation of patients with Kawasaki disease and its role in the pathogenesis of coronary artery lesions].

Objective: Kawasaki disease (KD) is an acute and self-limited systemic vasculitis syndrome of unknown origin that mainly affects small and medium-sized arteries, particularly the coronary arteries, which is followed by aneurysm formation. Increased levels of matrix metalloproteinase-1 (MMP-1) have been detected in aortic aneurysms in adults, suggesting an important role of MMP-1 in arterial wall destruction and resultant aneurysm formation. The aim of this study was to investigate the potential role of MMP-1 in the pathogenesis of coronary artery lesions in patients with KD.

Methods: Forty patients with KD, including 23 patients without coronary artery lesions (CAL) and 17 patients with CAL, as well as age-matched 10 febrile and 10 healthy afebrile controls were studied. The duration of KD was divided into three phases: the acute phase, the subacute phase and the convalescent phase. Enzyme-linked immunosorbent assay was used to detect the protein levels of MMP-1 in the sera. MMP-1 mRNA expression in the circulating leucocytes was studied using reverse transcription-polymerase chain reaction.

Results: Levels of MMP-1 protein in serum and MMP-1 mRNA expression in the leucocytes were significantly elevated at the acute phase in the two groups of KD patients (CAL group: 14.91 +/- 3.88 ng/ml and 0.89 +/- 0.15 ng/ml; NO-CAL group: 11.27 +/- 3.28 ng/ml and 0.77 +/- 0.14, respectively), compared with febrile (7.05 +/- 1.98 ng/ml and 0.45 +/- 0.12 ng/ml, respectively) and afebrile (5.13 +/- 1.20 ng/ml and 0.29 +/- 0.12 ng/ml, respectively) controls (P < 0.01). Furthermore, MMP-1 protein and MMP-1 mRNA levels were significantly higher in KD patients with CAL than in KD patients without CAL (P < 0.05). There was a significantly positive correlation between the serum protein level of MMP-1 at the acute phase of KD and the circulating leucocytes counts (r = 0.750, P < 0.01). The MMP-1 serum protein level and mRNA expression in the leucocytes at the acute phase of the two KD groups decreased obviously from the subacute through the convalescent phases (P < 0.05 or P < 0.01).

Conclusion: The expression of MMP-1 at the acute phase of KD was significantly elevated, especially in KD patients with CAL. MMP-1 might be involved in the formation of coronary artery lesions and pathogenesis of KD.