Reducing agalsidase beta infusion time in Fabry patients: low incidence of antibody formation and infusion-associated reactions in an Italian multicenter study.

BACKGROUND: Fabry disease is a rare progressive X-linked lysosomal storage disease caused by mutations in the GLA gene that encodes α-galactosidase A. Agalsidase beta is a recombinant enzyme replacement therapy authorized in Europe at a standard dose of 1.0 mg/kg intravenously every other week at an initial infusion rate of ≤ 0.25 mg/min until patient tolerance is established, after which the infusion rate may be increased gradually. However, specific practical guidance regarding the progressive reduction in infusion time is lacking. This study investigated a new and specific protocol for reducing agalsidase beta infusion time in which a stable dosage of 15 mg/h is infused for the first four months, and the infusion rate is increased progressively from 15 to 35 mg/h for the subsequent four infusions. The shortest infusion time is reached after six months and maintained thereafter. The incidence of infusion-associated reactions (IARs) and the development of anti-drug antibodies were analyzed, and the disease burden and the clinical evolution of the disease at 12 months were evaluated. RESULTS: Twenty-five of the 31 patients were naïve to enzyme or chaperone treatment at baseline and six patients had been switched from agalsidase alfa. The reduced infusion time protocol was well tolerated. Only one patient exhibited an IAR, with mild symptoms that resolved with low-dose steroids. Six patients globally seroconverted during treatment (4 with a classic phenotype and 2 with late-onset disease). All but three patients were seronegative at month 12. All patients were stable at the study's end (FAbry STabilization indEX value < 20%); reducing infusion time did not negatively impact clinical outcomes in any patient. The perceived medical assessment showed that the quality of life of all patients improved. CONCLUSIONS: The study demonstrates that reducing agalsidase beta infusion time is possible and safe from both an immunogenic and clinical point of view. The use of a low infusion rate in the first months when the probability of onset of the development of antibodies is higher contributed to very limited seroconversion to antibody-positive status.

Occult HBV infection in hemodialysis setting is marked by presence of isolated antibodies to HBcAg and HCV.

BACKGROUND: Hepatitis B virus (HBV) infections are a matter of concern in hemodialysis units; occult HBV infections (serum HBsAg negative but HBV DNA positive) were demonstrated in this setting, and this involves further concerns regarding possible transmission and pathogenic consequences. This study aimed to investigate the prevalence and correlates of occult HBV infection in a group of patients with reference to a single hemodialysis unit in southeastern Italy. METHODS: We analyzed HBV serology and DNA (using a qualitative nested PCR) in 128 HBsAg-negative hemodialysis patients, and correlated the results obtained, with sex, age, hemodialysis duration and HCV seropositivity. RESULTS: As a whole, occult HBV infection was demonstrated in 34/128 patients (26.6%); HBV DNA detection was more frequent when anti-HBcAg antibodies were detected in isolation (72%) than when associated with anti-HBsAg antibodies (31%). Among HCV-seropositive patients, occult HBV infection was observed in 66%, and among these as many as 14/15 patients (93%) who were HCV+/anti-HBcAg+ had serum HBV DNA detectable. On multivariate analysis, HCV seropositivity and the presence of anti-HBs were still respectively correlated to the presence and absence of occult HBV infection. CONCLUSIONS: Occult HBV infection is frequent among hemodialysis patients in our geographical area, particularly correlated to the presence of isolated anti-HBcAg and anti-HCV antibodies. Thus, the presence of isolated anti-HBcAg should prompt the clinician to evaluate a possible occult HBV infection especially if anti-HCV antibodies are also detectable; this condition, in fact, seems to strongly predict the detection of HBV DNA.