“…But a muscle biopsy taken at age one month displayed substantial extralysosomal glycogen storage, distinct ultrastructural abnormalities, and enhanced autophagy (Fig. 1), demonstrating that ERT in this new-born targeted to treat an already advanced stage of myopathy [5], [6].Fig. 1A muscle biopsy taken at age 1 month depicts a vacuolar myopathy (A).…”
“…But a muscle biopsy taken at age one month displayed substantial extralysosomal glycogen storage, distinct ultrastructural abnormalities, and enhanced autophagy (Fig. 1), demonstrating that ERT in this new-born targeted to treat an already advanced stage of myopathy [5], [6].Fig. 1A muscle biopsy taken at age 1 month depicts a vacuolar myopathy (A).…”
“…None of the patients had vacuolar myopathy. An increased intermyofibrillar network of glycogen was often detected, but none had globular accumulations of glycogen35 or regions of increased acid phosphatase activity within the sarcoplasm 30…”
AimsAs of 2016, there were five patients with Pompe in Slovenia (two infantile, one childhood and two adult onset) with a prevalence of 1:400 000; however, the prevalence of late-onset Pompe disease (LOPD) in some other countries means this ratio could be an underestimate. Since an LOPD muscle biopsy could be unspecific or even normal, the purpose of this study is to assess the prevalence of LOPD in patients with non-diagnostic muscle biopsies.MethodsSix hundred biopsies were recorded at the Neuromuscular Tissue Bank of the University of Ljubljana for the period 2004–2014. All adult patients with non-diagnostic muscle biopsies were invited to the National Slovenian Neuromuscular Centre for dried blood spot testing for LOPD.ResultsA total of 90 patients (56% of those invited) responded. No patient with LOPD was found. A total of 49 patients (54%) had fixed muscle weakness, 31 (34%) had mild symptoms and no weakness and 10 (11%) had asymptomatic hyperCKemia. Ventilatory insufficiency associated with proximal muscle weakness was found in two patients (2%). No patients exhibited vacuolar myopathy, globular accumulations of glycogen or regions of increased acid phosphatase activity within the sarcoplasm.ConclusionsThe study results do not support the hypothesis that LOPD is underestimated in Slovenian patients with non-diagnostic muscle biopsies; this could be consistent with the fact that LOPD is of low prevalence in Slovenia, as is the case in the populations of Finland, French-speaking Belgium, west Sweden and west Denmark.
“…Small samples were taken from open muscle biopsies and fixed in 4% glutaraldehyde/0.4MPBS and processed according to standard procedures. One to two µm semithin sections were cut from resin embedded tissue and stained with Periodic acid‐Schiff (PAS) and 2%‐p‐phenyldiamine (PPD) . Morphometric analysis of glycogen accumulation, large empty vacuoles (LEV) and pathology score were performed on PAS‐stained resin sections using a light microscope equipped with a motorized stage and digital camera with newCAST software as described before .…”
Section: Methodsmentioning
confidence: 99%
“…In individuals with LOPD, treatment with ERT reduces muscle weakness, respiratory insufficiency and mortality . The GAA enzyme defect leads to lysosomal and extra‐lysosomal accumulation of glycogen in striated muscles with disorganization of myofibrillar architecture and loss of function of the muscle cell . In addition, disturbed autophagy contributes to the muscle pathology and autophagic vacuoles (AV) are frequently present in muscle biopsies from patients with Pompe disease .…”
Section: Introductionmentioning
confidence: 99%
“…ERT leads to glycogen clearance in skeletal muscle from the individuals with IOPD and LOPD. Nevertheless, severely abnormal microscopic findings in skeletal muscle at the start of therapy are associated with a worse clinical outcome . Also, muscle pathology can progress even on ERT, a phenomenon, which is not well understood.…”
Muscle morphology in LOPD patients shows a high variability with, in most cases, moderate pathology.Increased pathology is associated with more fibrosis and autophagy.
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