The oxidation-reduction state of serum proteins in multiple sclerosis patients: effect of Interferon beta-1b

The concentration of reduction equivalents in serum was studied in a cohort of healthy individuals, in a group of multiple sclerosis (MS) patients und ergoing treatment with interferon beta-lb and another group of MS patients who refused treatment with interferon beta-lb. Two classes of sulfhydryl gr oups were detectable in serum: (1) the uncovered sulfhydryls, accessible to the oxidation-reduction substrate 5,5-dithiobis-(-2-nitrobenzoic acid) (DT NB); and (2) the hidden sulfhydryls that required previous heat denaturatio n of serum proteins to became accessible to DTNB. The concentration of the reduced form of both the uncovered- and hidden-type of sulfhydryls was high er in the serum of MS patients than in healthy individuals. Interferon beta -1b lowered the plasma concentration of the uncovered reduced sulfhydryls a fter 3 months of treatment. This was in contrast to a minor effect of inter feron beta-lb in the hidden-form of sulfhydryl groups. The results suggest that the concentration of reduced sulfhydryls is a biochemical marker of th e in vivo oxidation/reduction reactions in MS. (C) 1999 Elsevier Science Lt d. All rights reserved.