Early initiation of enzyme replacement therapy for the mucopolysaccharidoses

The mucopolysaccharidoses (MPS), a group of rare genetic disorders caused by defects in glycosaminoglycan (GAG) catabolism, are progressive, multi-systemic diseases with a high burden of morbidity. Enzyme replacement therapy (ERT) is available for MPS I, II, and VI, and may improve walking ability, endurance, and pulmonary function as evidenced by data from pivotal trials and extension studies. Despite these demonstrable benefits, cardiac valve disease, joint disease, and skeletal disease, all of which cause significant morbidity, do not generally improve with ERT if pathological changes are already established. Airway disease improves, but usually does not normalize. These limitations can be well understood by considering the varied functions of GAG in the body. Disruption of GAG catabolism has far-reaching effects due to the triggering of secondary pathogenic cascades. It appears that many of the consequences of these secondary pathogenic events, while they may improve on treatment, cannot be fully corrected even with long-term exposure to enzyme, thereby supporting the treatment of patients with MPS before the onset of clinical disease. This review examines the data from clinical trials and other studies in human patients to explore the limits of ERT as currently used, then discusses the pathophysiology, fetal tissue studies, animal studies, and sibling reports to explore the question of how early to treat an MPS patient with a firm diagnosis. The review is followed by an expert opinion on the rationale for and the benefits of early treatment

Idiopathic Gingival Hyperplasia: A Case Report with a 17-Year Followup

This is a case report of a patient with idiopathic gingival hyperplasia and an undiagnosed genetic disorder that demonstrated static encephalopathy, mental retardation, developmental delay, seizures, hypotonia, and severe gingival hypertrophy. The clinical dental management and attempts to obtain a genetic diagnosis are described

Improvement in time to treatment, but not time to diagnosis, in patients with mucopolysaccharidosis type I

Objective Early diagnosis and treatment initiation are important factors for successful treatment of mucopolysaccharidosis type I (MPS I). The purpose of this observational study was to assess whether age at diagnosis and time to first treatment for individuals with MPS I have improved over the last 15 years. Study design Data from the MPS I Registry (NCT00144794) for individuals with attenuated or severe disease who initiated therapy with laronidase enzyme replacement therapy (ERT) and/or hematopoietic stem cell transplantation (HSCT) between 1 January 2003 and 31 December 2017 were included. Results Data were available for 740 individuals with attenuated (n=291) or severe (n=424) MPS I (unknown n=25). Median age at diagnosis for attenuated disease did not change over time and ranged between 4.5 and 6 years of age while the median duration from diagnosis to first ERT decreased from 5.6 years before/during 2004 to 2.4 months in 2014–2017. For severe MPS I treated with HSCT, median age at diagnosis was less than 1 year and median time to first treatment was less than 3 months throughout the 15-year observation period. Conclusions Times to diagnosis and HSCT initiation for individuals with severe MPS I were consistent over time. For individuals with attenuated MPS I, the time to ERT initiation after diagnosis has improved substantially in the last 15 years, but median age at diagnosis has not improved. Efforts to improve early diagnosis in attenuated MPS I are needed to ensure that patients receive appropriate treatment at the optimal time

The Hunter Syndrome-Functional Outcomes for Clinical Understanding Scale (HS-FOCUS) Questionnaire: item reduction and further validation

The adsorption of blood proteins, serum albumin (BSA), immunoglobulin G (IgG) and fibrinogen (FGN), onto model SiO2 planar surfaces coated with poly-l-lysine/heparin multilayers (PLL/HEP) has been investigated by means of ellipsometry and quartz crystal microbalance with dissipation. Aiming at the development of low fouling coatings, this study has been focused on the effects that the number of layers and the type of polyelectrolyte present on the topmost layer have on the adsorption of these proteins. The three proteins interact with PLL-ended coatings whereas HEP-ended coatings prevent the adsorption of both BSA and IgG and induce a decrease in the adsorbed amount of FGN, down to 0.4 mg/m2 for three bilayers, as the number of PLL/HEP bilayers increases. These results suggest that heparin-ended multilayers prevent protein adsorption, which is an indicative of good blood compatibility. As a consequence we propose that PLL/HEP coatings could be used for the development of vascular medical devices

Progression of Polysomnographic Abnormalities in Mucolipidosis II (I-Cell Disease)

Mucolipidosis II (Inclusion cell or I-cell disease) is an autosomal recessive lysosomal storage disorder clinically comparable to the mucopolysaccharidoses (MPS), characterized by progressive respiratory and neurologic deterioration. Sleep problems, especially obstructive sleep apnea (OSA) and disrupted sleep architecture, are observed in other lysosomal storage diseases but have not been described in mucolipidosis II. We report the progression of polysomnographic abnormalities in a child with mucolipidosis II, demonstrated by worsening sleep-related hypoventilation, OSA, and sleep state fragmentation despite advancing PAP therapy. Background slowing and reduction in spindle activity on limited EEG may reflect progressive CNS disease affecting thalamic neurons

Evaluation of the long-term treatment efects of intravenous idursulfase in patients with mucopolysaccharidosis II (MPS II) using statistical modeling : data from the Hunter Outcome Survey (HOS)

Background: Mucopolysaccharidosis II (MPS II; Hunter syndrome) is a rare, life-limiting lysosomal storage disease caused by defcient iduronate-2-sulfatase activity. Enzyme replacement therapy (ERT) with intravenous (IV) idursulfase can stabilize or improve many somatic manifestations, but there remains a need for further analysis of long-term treatment outcomes. Using data from patients with MPS II enrolled in the Hunter Outcome Survey (HOS), mixed modeling was performed to evaluate and predict the efects of IV idursulfase treatment on selected clinical parameters for up to 8 years following treatment start. The modeling population comprised male patients followed prospectively in HOS who had received IV idursulfase for at least 5 years and who had data available for two or more time points (at least one post-ERT). Age at ERT start and time since ERT start were included as covariates. Results: In total, 481 patients were eligible for inclusion in at least one model. At 8 years post-ERT start, improvement from baseline was predicted for each age group (–75% in each group), mean left ventricular mass index (decreases of~1 g/m2 ) and mean palpable liver size (decreases of>2 cm). Improvements in mean 6-min walk test distance (increase of>50 m) and stabilization in percent predicted forced vital capacity and forced expiratory volume in 1 s (decreases of~4 and~9 percentage points, respectively) at 8 years post-ERT start were predicted for patients aged≥5 years at ERT start (these assessments are unsuitable for patients aged<5 years). Predicted changes over time were similar across the three age groups; however, overall outcomes were most favorable in children aged<18 months at ERT start. Conclusions: These fndings suggest that the previously reported positive efects of IV idursulfase on the somatic manifestations of MPS II are predicted to be maintained for at least 8 years following ERT initiation and highlight the value of statistical modeling to predict long-term treatment outcomes in patients with rare diseases

Positive-ion thermospray liquid chromatography--mass spectrometry: detection of organic acidurias

Positive-ion thermospray liquid chromatography--mass spectrometry (TSP-LC-MS) is used to detect organic acids via the direct injection of untreated urine from newborns and infants. Two methods are reported for the separation of organic acids. The separation of urinary organic acids is effected in either an acidic, pH 2.5 sulfuric acid, or a non-acidic, 0.05 M ammonium acetate, pH 6.8, mobile phase. Use of pH 2.5 sulfuric acid and an HPX-87H organic acid column produces better separation but has less sensitivity than the use of 0.05 M ammonium acetate, pH 6.8 and a C18 column. Positive ion TSP-LC-MS has been used to detect methylmalonic aciduria, 3-hydroxy-3-methylglutaric aciduria, propionic aciduria, isovaleric aciduria and argininosuccinic aciduria.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/28758/1/0000588.pd

Impact of the COVID-19 pandemic on the standard of care for patients with lysosomal storage diseases : a survey of healthcare professionals in the Fabry, Gaucher, and Hunter Outcome Survey registries

the needs of their healthcare providers were explored using a 12-question survey. Overall, 80/91 respondents (88%) indicated that the pandemic had negatively affected standards of care. With increased reliance on tele-medicine, the respondents highlighted the need for a personalized approach to care, direct and frequent communication with patients, and greater involvement of patients and caregivers