Biomolecules damage and redox status abnormalities in Fabry patients before and during enzyme replacement therapy

Fabry disease (FD) is caused by deficient activity of the lysosomal enzyme α-galactosidase A. Its substrates, mainly globotriaosylceramide (Gb3), accumulate and seem to induce other pathophysiological findings of FD. Once enzyme replacement therapy (ERT) is not completely efficient on preventing disease progress in FD patients, elucidating the underlying mechanisms in FD pathophysiology is essential to the development of additional therapeutic strategies. We investigated 58 Fabry patients (23 male and 35 female) subdivided into two groups (at diagnosis and during long-term ERT) and compared them to healthy individuals. Fabry patients at diagnosis presented altered glutathione (GSH) metabolism (higher GSH levels, lower glutathione peroxidase - GPx - and normal glutathione reductase - GR - activities), higher lipid peroxidation levels (thiobarbituric acid reactive species - TBARS - and malondialdehyde - MDA), nitric oxide (NO(.)) equivalents and urinary Gb3. Fabry patients on ERT presented GSH metabolism similar to controls, although lipid peroxidation and urinary levels of NO(.) equivalents remained higher whereas Gb3 levels were lower than at diagnosis but still higher than controls. These data demonstrated that redox impairment occurs in Fabry patients before and after ERT, probably as a consequence of Gb3 accumulation, providing targets to future therapy approaches using antioxidants in combination with ERT in FD.