Association between matrix metalloproteinase 9 promoter polymorphisms and Behçet's disease.

Matrix metalloproteinase (MMP)-9 expression is reported to be upregulated in several primary vasculitides. The -1562C>T and -91 [CA](n) repeat polymorphisms can affect MMP-9 promoter activity. We investigated the distributions of these functional polymorphisms in 122 patients with Behçet's disease (BD) and in 122 gender- and age-matched healthy controls. Plasma levels of MMP-9 were analyzed. The frequency of "L" alleles with [CA](n) <21 was significantly lower in all BD patients (vs controls, odds ratio (OR) = 0.371 [95% confidence interval 0.152-0.905]) and male patients (vs male controls, OR = 0.117 [0.019-0.737]). Furthermore, the frequency of "H/H" homozygote with [CA](n) > or = 21 was significantly higher in BD patients than controls (OR = 2.677 [1.065-6.729]). Moreover, the frequency of CL haplotype with lower promoter activity was significantly lower in BD patients (vs controls, OR = 0.374 [0.149-0.939]) and in BD patients with visceral involvement (OR = 0.202 [0.044-0.916]). Although plasma MMP-9 levels were not different between controls and BD patients, concentrations of this substance were significantly higher in male patients (vs male controls, p = 0.044) or patients with visceral involvements (vs patients without visceral involvement, p = 0.027). These results suggest that MMP-9 is a novel susceptibility gene and its promoter polymorphisms can affect the development of visceral involvement in BD. Copyright 2010 American Society for Histocompatibility and Immunogenetics. Published by Elsevier Inc. All rights reserved.