Hunter disease before and during enzyme replacement therapy.

Mucopolysaccharidosis type II (Hunter disease) is a lysosomal storage disease attributable to X-linked deficiency of the enzyme α-L-iduronate-sulfatase. Because of this deficiency, glycosaminoglycanes accumulate in various tissues and body fluids. We describe three patients representing the broad spectrum of Hunter disease and their response to enzyme replacement therapy. Patient 1 did not manifest central nervous system involvement, patient 2 manifested moderate neurologic disease, and patient 3 had already manifested a severe neurologic course during early infancy. In all patients, improvements in visceral organ size, physical capacity, and gastrointestinal functioning were reported. Moreover, all three patients demonstrated a gain in height, improved functioning of the upper limb, and a reduced need for antibiotics to treat upper airway infections. The response to enzyme replacement therapy occurred independent of type of genetic mutation (missense or frame shift), and we observed only mild infusion-related reactions. We conclude that all patients with mucopolysaccharidosis type II (those with and without clinical central nervous system involvement) may benefit from enzyme replacement therapy.

Sonographic ocular findings in patients with mucopolysaccharidoses I, II and VI.

BACKGROUND: Ophthalmological complications in patients with mucopolysaccharidosis (MPS) are clouding of the cornea, glaucoma, optic neuropathy, and degeneration of the retina. These changes may impair visual function to the point of total loss of vision. OBJECTIVE: To document the ophthalmological changes demonstrated by grey-scale US in patients with MPS. MATERIALS AND METHODS: A total of 65 patients with MPS (18 type I, 12 type II, 35 type VI) including a subgroup of 30 undergoing enzyme replacement therapy (ERT) were studied by US of the globe and optic nerve. RESULTS: Average scleral thickness at the posterior pole of the globe measured 2.02-2.58 mm (normal range 1.4-1.7 mm), the average diameter of the optic nerve and its sheath measured 5.35-6.71 mm (normal <4.5 mm). All medians were statistically significantly different from those of healthy volunteers. Concomitantly there was hypermetropia of up to 7.5 dioptres. During a mean follow-up of 3.1 years there was no distinct progression in scleral or optic nerve complex thickness. CONCLUSION: The optic nerve sheath and sclera were clearly thickened in comparison to normal values. Many morphological changes in the eye and optic nerve were already present at the time of the initial clinical diagnosis, and thus seem to develop very early in the course of the disease. ERT in our patients did not seem to alter the US characteristics of the globe or optic nerve.

Ocular changes in patients with mucopolysaccharidosis I receiving enzyme replacement therapy: a 4-year experience.

OBJECTIVE: To describe the progression of ocular changes in patients with mucopolysaccharidosis I receiving enzyme replacement therapy. METHODS: Three male and five female patients with mucopolysaccharidosis I were followed up for 4 years while undergoing enzyme replacement therapy with alpha-l-iduronidase (Aldurazyme). Visual acuity, corneal clouding, intraocular pressure, ophthalmoscopy, and optic disc measurements were performed yearly. RESULTS: Vision remained stable in 5 patients and deteriorated by at least 2 Snellen lines in 3 patients. Deterioration in 2 of these patients was related to progressive corneal clouding. Visual acuities improved in 1 patient after bilateral penetrating keratoplasties. In the third patient, deterioration was related to increasing papilloedema. All patients had typical corneal stromal opacities, however, to a variable extent. Two patients had already undergone corneal transplantation before recruitment in the study. Their grafts remained clear throughout follow-up. Of 2 patients with an elevated intraocular pressure, 1 developed intraocular pressure-related optic nerve damage. Vision remained stable in a patient with bilateral optic atrophy. CONCLUSIONS: Ocular findings remain stable in most patients with mucopolysaccharidosis I receiving enzyme replacement therapy. However, enzyme replacement therapy does not seem to prevent progression of corneal or optic disc changes and, thus, the related worsening of visual function.