Rate of disease progression during long-term follow-up of patients with late-onset Pompe disease.
ABSTRACT To determine the rate of disease progression in patients with late-onset Pompe disease, we collected longitudinal data on pulmonary function and skeletal muscle strength in 16 patients whose symptoms had started in childhood or adulthood. The mean duration of follow-up was 16 years (range 4-29 years). During the follow-up period, eight patients (50%) became wheelchair bound and three (19%) became ventilator dependent. At a group level, pulmonary function deteriorated by 1.6% per year, and proximal muscle weakness progressed gradually. At the individual level, however, the rate and extent of progression varied highly between patients. In two thirds of patients, pulmonary function and muscle strength declined simultaneously and to the same extent. The remaining one third of patients showed a variable, sometimes rapidly progressive course, leading to early respirator or wheelchair dependency. These individual differences, especially in pulmonary dysfunction, indicate the need for regular monitoring every 6-12 months depending on the rate of disease progression.
Article: The angiotensin-converting enzyme insertion/deletion polymorphism modifies the clinical outcome in patients with Pompe disease.[show abstract] [hide abstract]
ABSTRACT: The insertion/deletion polymorphism of angiotensin-converting enzyme may influence muscle properties. We examined whether Pompe disease clinical manifestations, which are known to be highly variable among late-onset patients, may be modulated by angiotensin-converting enzyme polymorphism. We included 38 patients with late-onset Pompe disease, aged 44.6 +/- 19.8 years. We compared the distribution of angiotensin-converting enzyme polymorphism according to demographic and disease parameters. The distribution of angiotensin-converting enzyme polymorphism was in line with the general population, with 16% of patients carrying the II genotype, 37% carrying the DD genotype, and the remaining patients with the ID genotype. The three groups did not differ in mean age, disease duration, Walton score, and other scores used to measure disease severity. The DD polymorphism was associated with earlier onset of disease (P = 0.041), higher creatine kinase levels at diagnosis (P = 0.024), presence of muscle pain (P = 0.014), and more severe rate of disease progression (P = 0.037, analysis of variance test for interaction). These findings suggest a potential role of angiotensin-converting enzyme polymorphism in modulating Pompe disease phenotype and prognosis.Genetics in medicine: official journal of the American College of Medical Genetics 03/2010; 12(4):206-11. · 3.92 Impact Factor
Article: Effect of enzyme therapy in juvenile patients with Pompe disease: a three-year open-label study.[show abstract] [hide abstract]
ABSTRACT: Pompe disease is a rare neuromuscular disorder caused by deficiency of acid α-glucosidase. Treatment with recombinant human α-glucosidase recently received marketing approval based on prolonged survival of affected infants. The current open-label study was performed to evaluate the response in older children (age 5.9-15.2 years). The five patients that we studied had limb-girdle muscle weakness and three of them also had decreased pulmonary function in upright and supine position. They received 20-mg/kg recombinant human α-glucosidase every two weeks over a 3-year period. No infusion-associated reactions were observed. Pulmonary function remained stable (n = 4) or improved slightly (n = 1). Muscle strength increased. Only one patient approached the normal range. Patients obtained higher scores on the Quick Motor Function Test. None of the patients deteriorated. Follow-up data of two unmatched historical cohorts of adults and children with Pompe disease were used for comparison. They showed an average decline in pulmonary function of 1.6% and 5% per year. Data on muscle strength and function of untreated children were not available. Further studies are required.Neuromuscular Disorders 12/2010; 20(12):775-82. · 2.80 Impact Factor
Article: Pompe disease gene therapy.[show abstract] [hide abstract]
ABSTRACT: Pompe disease is an autosomal recessive metabolic myopathy caused by the deficiency of the lysosomal enzyme acid alpha-glucosidase and results in cellular lysosomal and cytoplasmic glycogen accumulation. A wide spectrum of disease exists from hypotonia and severe cardiac hypertrophy in the first few months of life due to severe mutations to a milder form with the onset of symptoms in adulthood. In either condition, the involvement of several systems leads to progressive weakness and disability. In early-onset severe cases, the natural history is characteristically cardiorespiratory failure and death in the first year of life. Since the advent of enzyme replacement therapy (ERT), the clinical outcomes have improved. However, it has become apparent that a new natural history is being defined in which some patients have substantial improvement following ERT, while others develop chronic disability reminiscent of the late-onset disease. In order to improve on the current clinical outcomes in Pompe patients with diminished clinical response to ERT, we sought to address the cause and potential for the treatment of disease manifestations which are not amenable to ERT. In this review, we will focus on the preclinical studies that are relevant to the development of a gene therapy strategy for Pompe disease, and have led to the first clinical trial of recombinant adeno-associated virus-mediated gene-based therapy for Pompe disease. We will cover the preliminary laboratory studies and rationale for a clinical trial, which is based on the treatment of the high rate of respiratory failure in the early-onset patients receiving ERT.Human Molecular Genetics 04/2011; 20(R1):R61-8. · 7.64 Impact Factor