Long-term outcomes of systemic therapies for Hurler syndrome: an international multicenter comparison.

PURPOSE: Early treatment is critical for mucopolysaccharidosis type I (MPS I), justifying its incorporation into newborn screening. Enzyme replacement therapy (ERT) treats MPS I, yet presumptions that ERT cannot penetrate the blood-brain barrier (BBB) support recommendations that hematopoietic cell transplantation (HCT) treat the severe, neurodegenerative form (Hurler syndrome). Ethics precludes randomized comparison of ERT with HCT, but insight into this comparison is presented with an international cohort of patients with Hurler syndrome who received long-term ERT from a young age. METHODS: Long-term survival and neurologic outcomes were compared among three groups of patients with Hurler syndrome: 18 treated with ERT monotherapy (ERT group), 54 who underwent HCT (HCT group), and 23 who received no therapy (Untreated). All were followed starting before age 5 years. A sensitivity analysis restricted age of treatment below 3 years. RESULTS: Survival was worse when comparing ERT versus HCT, and Untreated versus ERT. The cumulative incidences of hydrocephalus and cervical spinal cord compression were greater in ERT versus HCT. Findings persisted in the sensitivity analysis. CONCLUSION: As newborn screening widens treatment opportunity for Hurler syndrome, this examination of early treatment quantifies some ERT benefit, supports presumptions about BBB impenetrability, and aligns with current guidelines to treat with HCT.

Vessel shape alterations of the vertebrobasilar arteries in Mucopolysaccharidosis type IVa (Morquio A) patients.

PURPOSE: Main symptom of mucopolysaccharidosis type IVa (MPS IVa) is progressive systemic skeletal dysplasia. This is routinely monitored by cerebral and spinal MRI. The vascular system is generally not in the primary focus of interest. In our population of MPS IVa patients we observed vessel shape alterations of the vertebrobasilar arteries, which has not been described before. MATERIAL AND METHODS: MRI-datasets of 26 patients with MPS IVa acquired between 2008 and 2015 were eligible for retrospective analysis of the vertebrobasilar arteries. The vessel length and angle of the basilar artery (BA) and both vertebral arteries (VA) were analyzed. A deflection angle between 90° and 130° in the vessel course was defined as tortuosity, less than 90° as kinking. The results were compared to a matched control group of 23 patients not suffering from MPS. RESULTS: The deflection angle [°] of the VA and BA was significantly decreased in the majority (85%) of MPS IVa patients compared to the control group: BA 132±24 vs. 177±6, BA/VA transition 113±21 vs. 152±13, right VA 108±23 vs. 156±13, left VA 110± 22 vs. 157±14 (all p<0.005). Likewise, vessels of MPS IVa patients were significantly longer compared to the control group: BA 27±4 vs. 21±2, right VA 20±6 vs. 10±1, left VA 18±5 vs. 11±2 (all p<0.005). CONCLUSION: MPS IVa is associated with significantly increased tortuosity of vertebrobasilar arteries. Therefore the vascular system of MPS IVa patients should be monitored on routinely basis, as vessel shape alterations had been associated with dissections, leading to a higher risk of cerebrovascular events.

Treatment with pentosan polysulphate in patients with MPS I: results from an open label, randomized, monocentric phase II study.

Current treatment options for MPS I have limited effects on some organs, including the skeletal system. In MPS animal models pentosan polysulphate (PPS) reduces the concentrations of glycosaminoglycans (GAGs) in tissues and body fluids and improves cartilaginous and osseous pathologies. The goals of this study were to investigate primarily the safety and secondary the clinical effects, concerning mobility and pain, of PPS treatment in MPS I patients. Four MPS I-Hurler-Scheie/-Scheie patients aged 35.6 ± 6.4 years with one male were included in the study. All patients were on enzyme replacement therapy since 9.45 ± 3.75 years. PPS was applied subcutaneously in two patients with 1 mg/kg and in two patients with 2 mg/kg, weekly for 12 weeks and then biweekly for 12 weeks. The 24-week treatment with PPS was well tolerated by all patients. Urinary GAG concentrations were reduced from 4.13 ± 1.17 at baseline to 2.69 ± 0.36 mg/mmol creatinine after 24-week treatment with 1 mg/kg PPS, and from 6.71 ± 0.62 to 2.65 ± 0.09 mg/mmol creatinine with 2 mg/kg PPS. An improvement in range of motion was noted in three out of four patients. The pain intensity score was reduced from 4.5 ± 1.77 at baseline to 1.8 ± 0.47 after 24-week treatment with 1 mg/kg PPS; patients with 2 mg/kg PPS already had minimal pain at the start of the study. In conclusion, PPS treatment in a small number of adult MPS I patients was well tolerated and resulted in a significant reduction of urinary GAG excretion and in an improvement of joint mobility and pain.