Early response to idursulfase treatment in a 3 year-old boy affected of Hunter syndrome.
ABSTRACT We present a 3-year-old boy affected with Hunter syndrome. When we first evaluated the patient glycosaminoglycans (GAG) in urine were elevated (94.6 ng/nmol/creatinine); the enzyme activity determined in serum was decreased (3.9 nmol/hxml) and the mutation found was N350H, exon 8. His clinical signs were coarse facial features, hepatomegaly (6 cm), splenomegaly (6 cm), elbow stiffness and hypospadias; dilatation of the perivascular spaces and white matter abnormalities, mitral regurgitation. After two weeks on enzyme replacement therapy (ERT) with idursulfase (IDS), the excretion of GAG was decreased to 36.2 ng/nmol/creatinine and the liver and spleen volumes were reduced to normal limits. He was subsequently noted to have a softer, finer skin, he had no further bouts of bronchitis, and his physical activity improved. This indicates that IDS in young children is well tolerated and that it has several effects which may confer clinical benefits with long-term therapy.
Article: The role of enzyme replacement therapy in severe Hunter syndrome-an expert panel consensus.[show abstract] [hide abstract]
ABSTRACT: Intravenous enzyme replacement therapy (ERT) with idursulfase for Hunter syndrome has not been demonstrated to and is not predicted to cross the blood-brain barrier. Nearly all published experience with ERT with idursulfase has therefore been in patients without cognitive impairment (attenuated phenotype). Little formal guidance is available on the issues surrounding ERT in cognitively impaired patients with the severe phenotype. An expert panel was therefore convened to provide guidance on these issues. The clinical experience of the panel with 66 patients suggests that somatic improvements (e.g., reduction in liver volume, increased mobility, and reduction in frequency of respiratory infections) may occur in most severe patients. Cognitive benefits have not been seen. It was agreed that, in general, severe patients are candidates for at least a 6-12-month trial of ERT, excluding patients who are severely neurologically impaired, those in a vegetative state, or those who have a condition that may lead to near-term death. It is imperative that the treating physician discuss the goals of treatment, methods of assessment of response, and criteria for discontinuation of treatment with the family before ERT is initiated. CONCLUSION: The decision to initiate ERT in severe Hunter syndrome should be made by the physician and parents and must be based on realistic expectations of benefits and risks, with the understanding that ERT may be withdrawn in the absence of demonstrable benefits.European Journal of Pediatrics 01/2012; 171(1):181-8. · 1.88 Impact Factor