Fabry disease in Spain: First analysis of the response to enzyme replacement therapy

BACKGROUND AND OBJECTIVE: Fabry disease is a X-linked lysosomal disorder caused by a deficient activity of the enzyme alfa-galactosidase A. Lack of enzyme activity results in progressive accumulation of globotriaosylceramide (Gb3) leading to multiorgan dysfunction and early death. Enzyme replacement therapy (ERT) has recently become available and the database Fabry Outcome Survey (FOS) of Spain gives us the opportunity to asses the efficacy of this therapy. Our objective is to describe the safety and the effects on renal, cardiac and neurological (pain) aspects of ERT with agalsidase alfa. PATIENTS AND METHOD: The effects of 1, 2, 3 and 4 years of ERT with agalsidase alfa on renal function (assessed by estimated glomerular filtration rate), proteinuria, heart size (assessed by echocardiography), arrhythmias, cardiac valvular anomalies and pain (assessed by the need of concomitant pain therapy) were analyzed in 33 patients under treatment. Safety of ERT was assessed by the reported infusion-related reactions in FOS. RESULTS: Overall, treatment with agalsidase alfa stabilized renal function, but the final result depends on the onset of ERT: there is a tendency to stabilization of renal function in those patients with mild deterioration of renal function, a tendency to improve in those patients with moderate deterioration and to worse in those with severe deterioration of renal function. Proteinuria and left ventricular heart size also estabilized under ERT, and pain improved. TSE infusion-related reactions occurred with an incidence of 0.7%. CONCLUSIONS: ERT with agalsidase alfa is safe and stabilized the abnormal clinical parameters observed in patients with Fabry disease.