Matrix metalloproteinase-2, -9, -12, and tissue inhibitor of metalloproteinase 2 gene polymorphisms and cutaneous expressions in patients with Behçet's disease.

Matrix metalloproteinases (MMPs) induce leukocyte migration into inflammation sites that lead to either promotion or repression of inflammation by activating or inactivating cytokines. An increased level of MMP-9 and a decreased level of MMP-2 have been observed in Behçet's disease (BD). This study was performed to analyze the relationship between MMP-2, -9, -12 and the tissue inhibitor of metalloproteinase-2 (TIMP-2) promoter polymorphisms in developing BD. The expression of MMP-2 and -9 was also evaluated in the skin of BD. The MMPs and TIMP-2 polymorphisms were confirmed by using polymerase chain reaction-restriction fragment length polymorphism in 251 BD and 312 controls. Cutaneous expression of MMP-2 and -9 in 17 BD patients with erythema nodosum (EN) or EN-like lesion was compared with 14 patients with idiopathic EN by immunohistochemical stains. The frequency of MMP-2-1575*G/*G and MMP-2-735*C/*C genotypes was shown to be lower in BD, whereas MMP-9-1562*C/*C was significantly higher in BD compared with the controls. The frequency of common haplotype MMP-2-1575*G -735*C was significantly lower in BD patients than in controls (P = 0.0046, permutation P = 0.009). No significant differences were observed between BD and controls in the allele and genotype frequencies of MMP-12-82A>G or TIMP-2-418G>C polymorphisms. The tissue expression of MMP-2, shown by immunohistochemistry, was significantly lower in BD compared with the controls. However, the expression of MMP-9 was significantly higher in BD. These results suggest that MMP-2 and -9 could each modulate the development of BD in opposite directions. Major genotypes of the MMP-2-1575*G/*G and MMP-2-735*C/*C and the common MMP-2-1575*G -735*C haplotype may provide some protection against development of BD, while MMP-9-1562*C/*C may promote the disease. The reciprocal expression of MMP-2 and -9 in the skin tissue of BD was also confirmed.