Serum levels of matrix metalloproteinase-9 and its tissue inhibitor (TIMP-1) in acute disseminated encephalomyelitis

In multiple sclerosis, there have been many reports on matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs). However, MMPs and TIMPs have not been reported in acute disseminated encephalomyelitis (ADEM). We determined the relationship between the serum concentrations of MMP-9 and TIMP-1 and activity of lesions on MRI in 14 patients with ADEM to investigate the roles of MMP-9 and TIMP-1 in the pathogenesis of ADEM. Serum MMP-9 and TIMP-1 levels, measured by ELISA and gadolinium-enhanced (Gd+) brain MRI, were analyzed. Serum MMP-9 and TIMP-1 levels at the acute stage were higher than controls, and the serum MMP-9 levels at the acute stage were higher than those at the convalescent stage in ADEM. In seven patients with Gd+ lesions on brain MRI, serum MMP-9 levels and the MMP-9/TIMP-1 ratio at the acute stage were higher than those at the convalescent stage, and serum TIMP1 levels at the acute stage were lower than those at the convalescent stage. In seven patients without Gd+ lesions on brain MRI, serum TIMP-1 levels at the acute stage were higher than those at the convalescent stage. We speculated that MMP-9 is related to lesion formation at the early stage in ADEM and that TIMP-1 is induced to modulate MMP-9 activity. These findings suggest that MMP-9 and TIMP-1 secondarily play some roles in the inflammatory cascade of ADEM.