[Pompe disease treated with enzyme replacement therapy in pregnancy]. / Tapasztalataink Pompe-betegségben terhesség alatt alkalmazott enzimpótló kezeléssel és az irodalom áttekintése.

Pompe disease is a rare lysosomal storage disease inherited in a recessive manner resulting muscular dystrophy. Due to the lack of the enzyme alpha glucosidase, glycogen accumulates in the cells. In the infantile form of Pompe disease hypotonia and severe cardio-respiratory failure are common leading to death within 2 years if left untreated, while the late-onset form is characterized with limb-girdle and axial muscle weakness accompanied with respiratory dysfunction. Pompe disease has been treated with regular intake of the missing enzyme since 2006, which significantly improved the survival and severity of symptoms in patients of both subtypes. The enzyme replacement therapy (ERT) is safe and well tolerated. However, limited data are available on its use in pregnancy. Our goal is to share our experience and review the literature on the safety of enzyme replacement therapy for Pompe disease during pregnancy and post partum.

[The long-term follow-up of enzyme replacement treatment in late onset Pompe disease]. / A késoi kezdetu Pompe-kórban szenvedok enzimpótló kezelésének hosszú távú követése.

Pompe disease (PD) is a rare lysosomal disease caused by the deficient activity of acid alpha-glucosidase (GAA) enzyme due to mutations in the GAA gene. The enzymatic deficiency leads to the accumulation of glycogen within the lysosomes. Clinically, the disease has been classically classified in infantile and childhood/adult forms. Presently cc. close to 600 mutations distributed throughout the whole gene have been reported. The c.-32-13T>G splice mutation that is very common in patients of Caucasian origin affected by the childhood/adult form of the disease, with an allelic frequency close to 70%. Enzyme replacement treatment (ERT) is available for the patients with Pompe disease (Myozyme). In this paper, we are presenting the long term follow up of 13 adult onset cases treated more than 5 years. The longest follow up was 15 years. To evaluate the treatment efficacy, the 6 minutes walking test (6MWT) and the respiratory functions were monitored annually. The analysis revealed that at the beginning of ERT for 3-4 years the 6MWT had been generally increasing, then it declined, and after 10 years it was lower in 77% of the cases than it had been at the start of the treatment. In 23% of the cases the 6MWT increased during the follow up time. Only one of the patients become wheelchair dependent during the follow-up period. The respiratory function showed similar results especially in supine position. A high degree of variability was observed among patients in their responses to the treatment, which only partially associated with the antibody titer against the therapeutic protein. The efficacy of the ERT was associated with the type of the disease causing mutation, the baseline status of the disease, the lifestyle and the diet of the patient. The long-term follow up of the patients with innovative orphan drugs is necessary to really understand the value of the treatment and the need of the patients.

Practical Recommendations for Diagnosis and Management of Respiratory Muscle Weakness in Late-Onset Pompe Disease.

Pompe disease is an autosomal-recessive lysosomal storage disorder characterized by progressive myopathy with proximal muscle weakness, respiratory muscle dysfunction, and cardiomyopathy (in infants only). In patients with juvenile or adult disease onset, respiratory muscle weakness may decline more rapidly than overall neurological disability. Sleep-disordered breathing, daytime hypercapnia, and the need for nocturnal ventilation eventually evolve in most patients. Additionally, respiratory muscle weakness leads to decreased cough and impaired airway clearance, increasing the risk of acute respiratory illness. Progressive respiratory muscle weakness is a major cause of morbidity and mortality in late-onset Pompe disease even if enzyme replacement therapy has been established. Practical knowledge of how to detect, monitor and manage respiratory muscle involvement is crucial for optimal patient care. A multidisciplinary approach combining the expertise of neurologists, pulmonologists, and intensive care specialists is needed. Based on the authors' own experience in over 200 patients, this article conveys expert recommendations for the diagnosis and management of respiratory muscle weakness and its sequelae in late-onset Pompe disease.

Motor function and respiratory capacity in patients with late-onset pompe disease.

INTRODUCTION: The relationship between skeletal muscle strength and respiratory dysfunction in Pompe disease has not been examined by quantitative methods. We investigated correlations among lower extremity proximal muscle strength, respiratory function, and motor performance. METHODS: Concentric strength of the knee extensor and flexor muscles was measured with a dynamometer, and pulmonary function was evaluated using spirometry in 7 adult patients. The 6-minute walk test and the 4-step stair-climb test were used for assessing aerobic endurance and anaerobic power, respectively. RESULTS: Anaerobic motor performance correlated with strength of both thigh muscles. Respiratory function did not correlate with either muscle strength or motor function performance. CONCLUSIONS: Respiratory and lower extremity proximal muscles could be affected differentially by the disease in individual patients. Motor performance is influenced by thigh muscle strength and is less dependent of respiratory capacity in our cohort of ambulatory patients.