Increased Plasma Matrix Metalloproteinase‐9 Levels in Migraineurs

Abstract

Cortical spreading depression and neurogenic inflammation have been hypothesized to be key steps in the development of migraine headache. Recent studies have highlighted matrix metalloproteinase-9 (MMP-9) in cortical spreading depression, neurogenic inflammation, and cerebral ischemia. To seek their possible association, we investigated plasma MMP-9 levels in migraineurs during headache-free periods. Plasma MMP-9 levels in 84 migraine subjects and 61 controls were determined by enzyme-linked immunosorbent assay. In addition, 23 patients with tension type headache were included in the study as comparative subjects. The MMP-9 levels in migraineurs (42.5+/-4.6 ng/mL, mean+/-SE) were significantly higher than those in controls (25.4+/-2.7 ng/mL, P< .005). Those levels in tension type headache subjects (24.6+/-4.8 ng/mL) did not differ from those in controls. There was no significant difference between subjects having migraine with aura and those without aura. The MMP-9 levels did not correlate with age, duration of illness, frequency of migraine attack, duration of headache attack, or medication for headache. Mean plasma MMP-9 levels were the highest in subjects from whom blood samples were taken 2-4 days after their latest attack. The degradation of extracellular matrix showing the increase of MMP-9 in migraineurs may be associated with an abnormality in their blood vessel permeability. MPP-9 plays some role in migraine pathophysiology. Further studies of MMPs are necessary to elucidate their role.