Significantly increased fractions of transformed to total α2-macroglobulin concentrations in plasma from patients with multiple sclerosis

We examined the proteinase inhibitor α₂-macroglobulin (α₂M) in plasma from patients with multiple sclerosis (MS); a neurological disease of the central nervous system. The plasma concentrations of native and transformed α₂M were measured in 90 patients with clinically definite MS, 73 with relapsing–remitting and 17 with secondary progressive MS, and 132 healthy individuals. Significantly lower concentrations of native α₂M and significantly higher concentrations of transformed α₂M were found in MS patients. A significant correlation between the concentrations of native and transformed α₂M was found. The fraction of transformed to total α₂M in the MS patients was 36% higher than in the healthy individuals. The results suggest an important involvement of α₂M in regulation of increased proteolytic activity occurring in MS disease.