Initially, IARs occurred usually between infusions 5 and 7 (coinciding with seroconversion)
Initially, IARs occurred usually between infusions 5 and 7 (coinciding with seroconversion). mean serum creatinine level and estimated glomerular filtration rate also remained stable after 30C36 mo of treatment. Infusion-associated reactions decreased over time, as did anti-rh-GalA IgG antibody titers. Among seroconverted patients, after 30C36 mo of treatment, seven patients tolerized (no detectable IgG antibody), and 59% had ?4-fold reductions in antibody titers. As of 30 mo into the extension trial, three patients were withdrawn from the study because of positive serum IgE or skin assessments; however, all have been rechallenged successfully at the time of PD-1-IN-17 this report. Thus, enzyme replacement therapy for 30C36 mo with agalsidase beta resulted in continuously decreased plasma GL-3 levels, sustained endothelial GL-3 clearance, stable kidney function, and a favorable safety profile. Introduction Fabry disease (MIM 301500) is an X-linked lysosomal storage disease resulting from the deficient activity of -galactosidase A and from the progressive accumulation of globotriaosylceramide (GL-3) and related glycosphingolipids in the plasma and in tissue lysosomes throughout the body (Desnick et al. 2001). In classically affected males, vascular endothelial GL-3 accumulation in the kidney, brain, and heart leads to early demise due to renal failure, stroke, and cardiovascular disease (Colombi et al. 1967; Desnick et al. 2001; MacDermot et al. 2001). A phase 1/2 clinical trial exhibited that five biweekly doses of 1 1.0 mg/kg of recombinant human -galactosidase A (rh-GalA) (agalsidase beta, Fabrazyme, Genzyme Corporation) reduced the accumulated GL-3 from the vascular endothelium of the kidney, heart, and skin of classically affected males (Eng et al. 2001162) from GL-3 during MS/MS analysis has permitted both confirmation of identity and development of a sensitive Rabbit Polyclonal to ATG4C quantification scheme. Total GL-3 PD-1-IN-17 is usually quantified by the sum of the 10 major isoforms (C16:0-, C18:0-, C20:0-, C22:0-, C22:1-, C22:0-OH, C24:0-, C24:1-, C24:0-OH, and C26:0-GL-3) measured in the plasma sample with the use of C17:0, a nonnaturally occuring isoform of GL-3, as an internal standard. The PD-1-IN-17 upper limit of normal for plasma GL-3, with the use of the more sensitive mass-spectrometric assay, was 7.03 g/ml, on the basis of the estimated 99th percentile value from 205 normal plasma samples PD-1-IN-17 from a blood bank (the mean SD of the 205 samples was 3.5 1.3 g/ml). Antibodies Blood was drawn prior to every other infusion, and the serum was screened for the presence of IgG antibodies against rh-GalA with the use of an ELISA specific for rh-GalA. The results were confirmed by a radioimmunoprecipitation (RIP) assay. Quantitation of the antibody was done by titrating the antibody reactivity with the ELISA assay, following a 2-fold dilution scheme starting at 1/100. Normal distribution studies of 100 normal human sera have shown that this initial dilution (1/100) had minimal reactivity in the ELISA and was essentially background for normal serum. If a patient did not seroconvert throughout the entire study period, then the patient was defined as having no immune response (seronegative). If a patient seroconverted and later ceased producing IgG antibodies, as determined by the ELISA assay within the normal range and by two consecutive unfavorable confirmatory RIP assays, then the patient was defined as having tolerized. The remaining patients who seroconverted without tolerizing were classified as follows. Low responders were defined as those who did not tolerize and whose highest titer value was ?800 (i.e., 1:8 above background). Patients who did not tolerize and had at PD-1-IN-17 least one titer value 800 and a 4-fold decrease in titer from the peak to the last value were designated as using a downward pattern. Patients for whom at least one titer was 800 and the highest titer to date was achieved at the last visit were given the.