Serum gelatinase B/MMP-9 in primary progressive multiple sclerosis patients treated with interferon-beta-1a

Interferon- beta (IFNbeta) acts by a variety of mechanisms in relapsing-remitting multiple sclerosis (MS). One of these is a cellular down-regulation of gelatinase B or matrix metalloproteinase-9 (MMP-9), which is known from biochemical, biological and immunohistochemical evidences to play a disease-promoting role in MS. a) To investigate the influence of IFNbeta-1a (30 or 60 micro g I. M./week) on serum MMP-9 levels in patients with primary progressive MS (PPMS). b) To correlate serum MMP-9 levels with clinical and magnetic resonance imaging (MRI) findings. Serial blood samples were collected every 3 months from 49 patients participating in a phase II trial of IFNbeta-1a in PPMS. Serum MMP-9 was quantified by ELISA and correlations with clinical (EDSS) as well as MRI findings (brain and spinal cord atrophy, ventricular volume, T1 and T2 lesion load) were calculated. No significant differences were found between serial serum MMP-9 levels in IFNbeta-treated versus placebo-treated patients. MMP-9 levels did not differ between patients who progressed or did not progress during the study interval. Although mean absolute serum MMP-9 levels over the study period correlated with an increase in T2 lesion load (relative T2 change: r=0.51, p