Browsing by Subject "Glycogen Storage Disease Type II"
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Item Open Access Adjunctive albuterol enhances the response to enzyme replacement therapy in late-onset Pompe disease.(FASEB J, 2014-05) Koeberl, Dwight D; Austin, Stephanie; Case, Laura E; Smith, Edward C; Buckley, Anne F; Young, Sarah P; Bali, Deeksha; Kishnani, Priya SEffective dosages for enzyme replacement therapy (ERT) in Pompe disease are much higher than for other lysosomal storage disorders, which has been attributed to low cation-independent mannose-6-phosphate receptor (CI-MPR) in skeletal muscle. We have previously demonstrated the benefit of increased CI-MPR-mediated uptake of recombinant human acid-α-glucosidase during ERT in mice with Pompe disease following addition of albuterol therapy. Currently we have completed a pilot study of albuterol in patients with late-onset Pompe disease already on ERT for >2 yr, who were not improving further. The 6-min walk test (6MWT) distance increased in all 7 subjects at wk 6 (30±13 m; P=0.002), wk 12 (34±14 m; P=0.004), and wk 24 (42±37 m; P=0.02), in comparison with baseline. Grip strength was improved significantly for both hands at wk 12. Furthermore, individual subjects reported benefits; e.g., a female patient could stand up from sitting on the floor much more easily (time for supine to standing position decreased from 30 to 11 s), and a male patient could readily swing his legs out of his van seat (hip abduction increased from 1 to 2+ on manual muscle testing). Finally, analysis of the quadriceps biopsies suggested increased CI-MPR at wk 12 (P=0.08), compared with baseline. With the exception of 1 patient who succumbed to respiratory complications of Pompe disease in the first week, only mild adverse events have been reported, including tremor, transient difficulty falling asleep, and mild urinary retention (requiring early morning voiding). Therefore, this pilot study revealed initial safety and efficacy in an open label study of adjunctive albuterol therapy in patients with late-onset Pompe disease who had been stable on ERT with no improvements noted over the previous several years.Item Open Access Adjunctive β2-agonist treatment reduces glycogen independently of receptor-mediated acid α-glucosidase uptake in the limb muscles of mice with Pompe disease.(FASEB J, 2014-05) Farah, Benjamin L; Madden, Lauran; Li, Songtao; Nance, Sierra; Bird, Andrew; Bursac, Nenad; Yen, Paul M; Young, Sarah P; Koeberl, Dwight DEnzyme or gene replacement therapy with acid α-glucosidase (GAA) has achieved only partial efficacy in Pompe disease. We evaluated the effect of adjunctive clenbuterol treatment on cation-independent mannose-6-phosphate receptor (CI-MPR)-mediated uptake and intracellular trafficking of GAA during muscle-specific GAA expression with an adeno-associated virus (AAV) vector in GAA-knockout (KO) mice. Clenbuterol, which increases expression of CI-MPR in muscle, was administered with the AAV vector. This combination therapy increased latency during rotarod and wirehang testing at 12 wk, in comparison with vector alone. The mean urinary glucose tetrasaccharide (Glc4), a urinary biomarker, was lower in GAA-KO mice following combination therapy, compared with vector alone. Similarly, glycogen content was lower in cardiac and skeletal muscle following 12 wk of combination therapy in heart, quadriceps, diaphragm, and soleus, compared with vector alone. These data suggested that clenbuterol treatment enhanced trafficking of GAA to lysosomes, given that GAA was expressed within myofibers. The integral role of CI-MPR was demonstrated by the lack of effectiveness from clenbuterol in GAA-KO mice that lacked CI-MPR in muscle, where it failed to reverse the high glycogen content of the heart and diaphragm or impaired wirehang performance. However, the glycogen content of skeletal muscle was reduced by the addition of clenbuterol in the absence of CI-MPR, as was lysosomal vacuolation, which correlated with increased AKT signaling. In summary, β2-agonist treatment enhanced CI-MPR-mediated uptake and trafficking of GAA in mice with Pompe disease, and a similarly enhanced benefit might be expected in other lysosomal storage disorders.Item Open Access Adjunctive β2-agonists reverse neuromuscular involvement in murine Pompe disease.(FASEB J, 2013-01) Li, Songtao; Sun, Baodong; Nilsson, Mats I; Bird, Andrew; Tarnopolsky, Mark A; Thurberg, Beth L; Bali, Deeksha; Koeberl, Dwight DPompe disease has resisted enzyme replacement therapy with acid α-glucosidase (GAA), which has been attributed to inefficient cation-independent mannose-6-phosphate receptor (CI-MPR) mediated uptake. We evaluated β2-agonist drugs, which increased CI-MPR expression in GAA knockout (KO) mice. Clenbuterol along with a low-dose adeno-associated virus vector increased Rotarod latency by 75% at 4 wk, in comparison with vector alone (P<2×10(-5)). Glycogen content was lower in skeletal muscles, including soleus (P<0.01), extensor digitorum longus (EDL; P<0.001), and tibialis anterior (P<0.05) following combination therapy, in comparison with vector alone. Glycogen remained elevated in the muscles following clenbuterol alone, indicating an adjunctive effect with gene therapy. Elderly GAA-KO mice treated with combination therapy demonstrated 2-fold increased wirehang latency, in comparison with vector or clenbuterol alone (P<0.001). The glycogen content of skeletal muscle decreased following combination therapy in elderly mice (P<0.05). Finally, CI-MPR-KO/GAA-KO mice did not respond to combination therapy, indicating that clenbuterol's effect depended on CI-MPR expression. In summary, adjunctive β2-agonist treatment increased CI-MPR expression and enhanced efficacy from gene therapy in Pompe disease, which has implications for other lysosomal storage disorders that involve primarily the brain.Item Open Access Algorithm for the early diagnosis and treatment of patients with cross reactive immunologic material-negative classic infantile pompe disease: a step towards improving the efficacy of ERT.(PLoS One, 2013) Banugaria, Suhrad G; Prater, Sean N; Patel, Trusha T; Dearmey, Stephanie M; Milleson, Christie; Sheets, Kathryn B; Bali, Deeksha S; Rehder, Catherine W; Raiman, Julian AJ; Wang, Raymond A; Labarthe, Francois; Charrow, Joel; Harmatz, Paul; Chakraborty, Pranesh; Rosenberg, Amy S; Kishnani, Priya SOBJECTIVE: Although enzyme replacement therapy (ERT) is a highly effective therapy, CRIM-negative (CN) infantile Pompe disease (IPD) patients typically mount a strong immune response which abrogates the efficacy of ERT, resulting in clinical decline and death. This study was designed to demonstrate that immune tolerance induction (ITI) prevents or diminishes the development of antibody titers, resulting in a better clinical outcome compared to CN IPD patients treated with ERT monotherapy. METHODS: We evaluated the safety, efficacy and feasibility of a clinical algorithm designed to accurately identify CN IPD patients and minimize delays between CRIM status determination and initiation of an ITI regimen (combination of rituximab, methotrexate and IVIG) concurrent with ERT. Clinical and laboratory data including measures of efficacy analysis for response to ERT were analyzed and compared to CN IPD patients treated with ERT monotherapy. RESULTS: Seven CN IPD patients were identified and started on the ITI regimen concurrent with ERT. Median time from diagnosis of CN status to commencement of ERT and ITI was 0.5 months (range: 0.1-1.6 months). At baseline, all patients had significant cardiomyopathy and all but one required respiratory support. The ITI regimen was safely tolerated in all seven cases. Four patients never seroconverted and remained antibody-free. One patient died from respiratory failure. Two patients required another course of the ITI regimen. In addition to their clinical improvement, the antibody titers observed in these patients were much lower than those seen in ERT monotherapy treated CN patients. CONCLUSIONS: The ITI regimen appears safe and efficacious and holds promise in altering the natural history of CN IPD by increasing ERT efficacy. An algorithm such as this substantiates the benefits of accelerated diagnosis and management of CN IPD patients, thus, further supporting the importance of early identification and treatment initiation with newborn screening for IPD.Item Open Access Antibody formation and mannose-6-phosphate receptor expression impact the efficacy of muscle-specific transgene expression in murine Pompe disease.(J Gene Med, 2010-11) Sun, Baodong; Li, Songtao; Bird, Andrew; Yi, Haiqing; Kemper, Alex; Thurberg, Beth L; Koeberl, Dwight DBACKGROUND: Lysosomal storage disorders such as Pompe disease can be more effectively treated, if immune tolerance to enzyme or gene replacement therapy can be achieved. Alternatively, immune responses against acid α-glucosidase (GAA) might be evaded in Pompe disease through muscle-specific expression of GAA with adeno-associated virus (AAV) vectors. METHODS: An AAV vector containing the MHCK7 regulatory cassette to drive muscle-specific GAA expression was administered to GAA knockout (KO) mice, immune tolerant GAA-KO mice and mannose-6-phosphate deficient GAA-KO mice. GAA activity and glycogen content were analyzed in striated muscle to determine biochemical efficacy. RESULTS: The biochemical efficacy from GAA expression was slightly reduced in GAA-KO mice, as demonstrated by higher residual glycogen content in skeletal muscles. Next, immune tolerance to GAA was induced in GAA-KO mice by co-administration of a second AAV vector encoding liver-specific GAA along with the AAV vector encoding muscle-specific GAA. Antibody formation was prevented by liver-specific GAA, and the biochemical efficacy of GAA expression was improved in the absence of antibodies, as demonstrated by significantly reduced glycogen content in the diaphragm. Efficacy was reduced in old GAA-KO mice despite the absence of antibodies. The greatest impact upon gene therapy was observed in GAA-KO mice lacking the mannose-6-phosphate receptor in muscle. The clearance of stored glycogen was markedly impaired despite high GAA expression in receptor-deficient Pompe disease mice. CONCLUSIONS: Overall, antibody formation had a subtle effect upon efficacy, whereas the absence of mannose-6-phosphate receptors markedly impaired muscle-targeted gene therapy in murine Pompe disease.Item Open Access Correlation between quantitative whole-body muscle magnetic resonance imaging and clinical muscle weakness in Pompe disease.(Muscle & nerve, 2015-05) Horvath, Jeffrey J; Austin, Stephanie L; Case, Laura E; Greene, Karla B; Jones, Harrison N; Soher, Brian J; Kishnani, Priya S; Bashir, Mustafa RIntroduction
Previous examination of whole-body muscle involvement in Pompe disease has been limited to physical examination and/or qualitative magnetic resonance imaging (MRI). In this study we assess the feasibility of quantitative proton-density fat-fraction (PDFF) whole-body MRI in late-onset Pompe disease (LOPD) and compare the results with manual muscle testing.Methods
Seven LOPD patients and 11 disease-free controls underwent whole-body PDFF MRI. Quantitative MR muscle group assessments were compared with physical testing of muscle groups.Results
The 95% upper limits of confidence intervals for muscle groups were 4.9-12.6% in controls and 6.8-76.4% in LOPD patients. LOPD patients showed severe and consistent tongue and axial muscle group involvement, with less marked involvement of peripheral musculature. MRI was more sensitive than physical examination for detection of abnormality in multiple muscle groups.Conclusion
This integrated, quantitative approach to muscle assessment provides more detailed data than physical examination and may have clinical utility for monitoring disease progression and treatment response.Item Open Access Early clinical phenotype of late onset Pompe disease: Lessons learned from newborn screening.(Molecular genetics and metabolism, 2022-03) Huggins, Erin; Holland, Maggie; Case, Laura E; Blount, Janet; Landstrom, Andrew P; Jones, Harrison N; Kishnani, Priya SPurpose
Thoroughly phenotype children with late-onset Pompe disease (LOPD) diagnosed via newborn screening (NBS) to provide guidance for long-term follow up.Methods
Twenty infants ages 6-21 months with LOPD diagnosed by NBS underwent systematic clinical evaluation at Duke University including cardiac imaging, biomarker testing, physical therapy evaluation, and speech-language pathology evaluation.Results
Of the 20 infants, four were homozygous for the "late-onset" IVS1 splice site variant c.-32-13 T > G, fourteen were compound heterozygous, and two did not have any copies of this variant. None of the patients had evidence of cardiomyopathy or cardiac rhythm disturbances. Biomarker testing showed an increase in CK, AST, and ALT in 8 patients (40%) and increase in Glc4 in two patients (10%). All patients demonstrated postural and kinematic concerns. Three patients (17%) scored below the 10%ile on the Alberta Infant Motor Scale (AIMS) and 15 patients (83%) scored above the 10%ile. Speech-language pathology assessments were normal in all patients and mild feeding/swallowing abnormalities were noted in nine patients (45%).Conclusion
Our data show high variability among children with LOPD diagnosed via NBS. Careful physical therapy evaluation is necessary to monitor for subtle musculoskeletal signs that may reflect early muscle involvement. Patients should be monitored closely for symptom progression.Item Open Access Early cognitive development in children with infantile Pompe disease.(Molecular genetics and metabolism, 2012-03) Spiridigliozzi, Gail A; Heller, James H; Case, Laura E; Jones, Harrison N; Kishnani, Priya SThis report describes the cognitive development of 17 children with infantile Pompe disease who participated in a 52-week clinical trial of enzyme replacement therapy (ERT) via biweekly infusion of Myozyme® (alglucosidase alfa). Subjects were six months of age or younger (adjusted for gestational age) upon initiation of ERT. The Mental Scale of the Bayley Scales of Infant Development-Second Edition (BSID-II) was administered to obtain a Mental Development Index (MDI) at baseline and weeks 12, 26, 38, and 52 of ERT to assess cognitive development in this treated cohort. Data regarding motor development were also obtained at the same visits and these were used to determine correlations between cognitive and motor development. Over the course of the study, two subgroups of subjects emerged: high responders who were sitting independently and/or ambulating by week 52 (n=13) and limited responders who showed minimal motor gains throughout the first year of ERT (n=4). In the high responder group, MDI scores on the BSID-II remained stable throughout the study and were within normal limits. Positive correlations between cognitive and motor development were also present. These data suggest that the cognitive function of infants up to 18 months of age with Pompe disease is unaffected by the possible presence of glycogen in the central nervous system. Continued investigation of the cognitive development of older survivors is warranted.Item Open Access Effects of respiratory muscle training (RMT) in children with infantile-onset Pompe disease and respiratory muscle weakness.(Journal of pediatric rehabilitation medicine, 2014-01) Jones, Harrison N; Crisp, Kelly D; Moss, Tronda; Strollo, Katherine; Robey, Randy; Sank, Jeffrey; Canfield, Michelle; Case, Laura E; Mahler, Leslie; Kravitz, Richard M; Kishnani, Priya SPurpose
Respiratory muscle weakness is a primary therapeutic challenge for patients with infantile Pompe disease. We previously described the clinical implementation of a respiratory muscle training (RMT) regimen in two adults with late-onset Pompe disease; both demonstrated marked increases in inspiratory and expiratory muscle strength in response to RMT. However, the use of RMT in pediatric survivors of infantile Pompe disease has not been previously reported.Method
We report the effects of an intensive RMT program on maximum inspiratory pressure (MIP) and maximum expiratory pressure (MEP) using A-B-A (baseline-treatment-posttest) single subject experimental design in two pediatric survivors of infantile Pompe disease. Both subjects had persistent respiratory muscle weakness despite long-term treatment with alglucosidase alfa.Results
Subject 1 demonstrated negligible to modest increases in MIP/MEP (6% increase in MIP, d=0.25; 19% increase in MEP, d=0.87), while Subject 2 demonstrated very large increases in MIP/MEP (45% increase in MIP, d=2.38; 81% increase in MEP, d=4.31). Following three-month RMT withdrawal, both subjects maintained these strength increases and demonstrated maximal MIP and MEP values at follow-up.Conclusion
Intensive RMT may be a beneficial treatment for respiratory muscle weakness in pediatric survivors of infantile Pompe disease.Item Open Access Enhanced efficacy of enzyme replacement therapy in Pompe disease through mannose-6-phosphate receptor expression in skeletal muscle.(Mol Genet Metab, 2011-06) Koeberl, Dwight D; Luo, Xiaoyan; Sun, Baodong; McVie-Wylie, Alison; Dai, Jian; Li, Songtao; Banugaria, Suhrad G; Chen, Y-T; Bali, Deeksha SEnzyme replacement therapy (ERT) with acid α-glucosidase has become available for Pompe disease; however, the response of skeletal muscle, as opposed to the heart, has been attenuated. The poor response of skeletal muscle has been attributed to the low abundance of the cation-independent mannose-6-phosphate receptor (CI-MPR) in skeletal muscle compared to heart. To further understand the role of CI-MPR in Pompe disease, muscle-specific CI-MPR conditional knockout (KO) mice were crossed with GAA-KO (Pompe disease) mice. We evaluated the impact of CI-MPR-mediated uptake of GAA by evaluating ERT in CI-MPR-KO/GAA-KO (double KO) mice. The essential role of CI-MPR was emphasized by the lack of efficacy of ERT as demonstrated by markedly reduced biochemical correction of GAA deficiency and of glycogen accumulations in double KO mice, in comparison with the administration of the same therapeutic doses in GAA-KO mice. Clenbuterol, a selective β(2)-agonist, enhanced the CI-MPR expression in skeletal tissue and also increased efficacy from GAA therapy, thereby confirming the key role of CI-MPR with regard to enzyme replacement therapy in Pompe disease. Biochemical correction improved in both muscle and non-muscle tissues, indicating that therapy could be similarly enhanced in other lysosomal storage disorders. In summary, enhanced CI-MPR expression might improve the efficacy of enzyme replacement therapy in Pompe disease through enhancing receptor-mediated uptake of GAA.Item Open Access Evaluation of antihypertensive drugs in combination with enzyme replacement therapy in mice with Pompe disease.(Molecular genetics and metabolism, 2020-02) Han, Sang-Oh; Haynes, Alexina C; Li, Songtao; Abraham, Dennis M; Kishnani, Priya S; Steet, Richard; Koeberl, Dwight DPompe disease is caused by the deficiency of lysosomal acid α-glucosidase (GAA) leading to progressive myopathy. Enzyme replacement therapy (ERT) with recombinant human (rh) GAA has limitations, including inefficient uptake of rhGAA in skeletal muscle linked to low cation-independent mannose-6-phosphate receptor (CI-MPR) expression.Purpose
To test the hypothesis that antihypertensive agents causing muscle hypertrophy by increasing insulin-like growth factor 1 expression can increase CI-MPR-mediated uptake of recombinant enzyme with therapeutic effects in skeletal muscle.Methods
Three such agents were evaluated in mice with Pompe disease (carvedilol, losartan, and propranolol), either with or without concurrent ERT.Results
Carvedilol, a selective β-blocker, increased muscle strength but reduced biochemical correction from ERT. Administration of drugs alone had minimal effect, with the exception of losartan that increased glycogen storage and mortality either by itself or in combination with ERT.Conclusion
The β-blocker carvedilol had beneficial effects during ERT in mice with Pompe disease, in comparison with propranolol or losartan. Caution is warranted when prescribing antihypertensive drugs in Pompe disease.Item Open Access Expanding the phenotype of late-onset Pompe disease: tongue weakness: a new clinical observation.(Muscle & nerve, 2011-12) Dubrovsky, Alberto; Corderi, Jose; Lin, Min; Kishnani, Priya S; Jones, Harrison NIntroduction
Following the clinical observation of lingual weakness in 2 patients with late-onset Pompe disease (LOPD), tongue strength was assessed in 19 consecutive patients to determine the frequency and severity of this neurological sign.Methods
Lingual strength was assessed using manual muscle testing; if weakness was present, severity was established as mild, moderate, or severe.Results
All the patients exhibited lingual weakness, even 2 asymptomatic patients with a positive family history. Weakness was mild in 12 (63%), moderate in 6 (32%), and severe in 1 (5%). Dysarthria and/or dysphagia were observed or reported in 7 of 19 (37%) patients.Conclusions
Lingual weakness may be present as an axial sign of LOPD, even relatively early in the disease course, and may contribute to the differential diagnosis of this now treatable condition. Dysphagia and/or dysarthria may also occur. This finding further expands the phenotype of LOPD.Item Open Access Higher dosing of alglucosidase alfa improves outcomes in children with Pompe disease: a clinical study and review of the literature.(Genetics in medicine : official journal of the American College of Medical Genetics, 2020-05) Khan, Aleena A; Case, Laura E; Herbert, Mrudu; DeArmey, Stephanie; Jones, Harrison; Crisp, Kelly; Zimmerman, Kanecia; ElMallah, Mai K; Young, Sarah P; Kishnani, Priya SPurpose
Enzyme replacement therapy (ERT) with recombinant human acid-α glucosidase (rhGAA) at standard dose of 20 mg/kg every other week is insufficient to halt the long-term progression of myopathy in Pompe disease.Methods
We conducted a retrospective study on infantile-onset Pompe disease (IPD) and late-onset Pompe disease (LOPD) patients with onset before age 5 years, ≥12 months of treatment with standard dose ERT, and rhGAA immunogenic tolerance prior to dose escalation. Long-term follow-up of up to 18 years was obtained. We obtained physical therapy, lingual strength, biochemical, and pulmonary assessments as dose was escalated.Results
Eleven patients with IPD (n = 7) or LOPD (n = 4) were treated with higher doses of up to 40 mg/kg weekly. There were improvements in gross motor function measure in 9/10 patients, in lingual strength in 6/6 patients, and in pulmonary function in 4/11. Significant reductions in urinary glucose tetrasaccharide, creatine kinase, aspartate aminotransferase, and alanine aminotransferase were observed at 40 mg/kg weekly compared with lower doses (p < 0.05). No safety or immunogenicity concerns were observed at higher doses.Conclusion
Higher rhGAA doses are safe, improve gross motor outcomes, lingual strength, pulmonary function measures, and biochemical markers in early-onset Pompe disease, and should be considered in patients with clinical and functional decline.Item Open Access Hydrostatic isolated limb perfusion with adeno-associated virus vectors enhances correction of skeletal muscle in Pompe disease.(Gene Ther, 2010-12) Sun, B; Li, S; Bird, A; Koeberl, DDGlycogen storage disease type II (Pompe disease; MIM 232300) stems from the inherited deficiency of acid-α-glucosidase (GAA; acid maltase; EC 3.2.1.20), which primarily involves cardiac and skeletal muscles. We hypothesized that hydrostatic isolated limb perfusion (ILP) administration of an adeno-associated virus (AAV) vector containing a muscle-specific promoter could achieve relatively higher transgene expression in the hindlimb muscles of GAA-knockout (GAA-KO) mice, in comparison with intravenous (IV) administration. ILP administration of AAV2/8 vectors encoding alkaline phosphatase or human GAA-transduced skeletal muscles of the hindlimb widely, despite the relatively low number of vector particles administered (1 × 10¹¹), and IV administration of an equivalent vector dose failed to transduce skeletal muscle detectably. Similarly, ILP administration of fewer vector particles of the AAV2/9 vector encoding human GAA (3 × 10¹⁰) transduced skeletal muscles of the hindlimb widely and significantly reduced glycogen content to, in comparison with IV administration. The only advantage for IV administration was moderately high-level transduction of cardiac muscle, which demonstrated compellingly that ILP administration sequestered vector particles within the perfused limb. Reduction of glycogen storage in the extensor digitorum longus demonstrated the potential advantage of ILP-mediated delivery of AAV vectors in Pompe disease, because type II myofibers are resistant to enzyme replacement therapy. Thus, ILP will enhance AAV transduction of multiple skeletal muscles while reducing the required dosages in terms of vector particle numbers.Item Open Access Immunodominant liver-specific expression suppresses transgene-directed immune responses in murine pompe disease.(Hum Gene Ther, 2012-05) Zhang, P; Sun, B; Osada, T; Rodriguiz, R; Yang, XY; Luo, X; Kemper, AR; Clay, TM; Koeberl, DDPompe disease can be treated effectively, if immune tolerance to enzyme replacement therapy (ERT) with acid α-glucosidase (GAA) is present. An adeno-associated viral (AAV) vector carrying a liver-specific regulatory cassette to drive GAA expression (AAV-LSPhGAA) established immune tolerance in GAA knockout (KO) mice, whereas ubiquitous expression with AAV-CBhGAA provoked immune responses. Therefore, we investigated the hypothesis that immune tolerance induced by hepatic-restricted expression was dominant. AAV-LSPhGAA and AAV-CBhGAA were administered singly or in combination to groups of adult GAA-KO mice, and AAV-LSPhGAA induced immune tolerance even in combination with AAV-CBhGAA. The dual vector approach to GAA expression improved biochemical correction of GAA deficiency and glycogen accumulations at 18 weeks, and improved motor function testing including wire-hang and grip-strength testing. The greatest efficacy was demonstrated by dual vector administration, when both vectors were pseudotyped as AAV8. T cells from mice injected with AAV-LSPhGAA failed to proliferate at all after an immune challenge with GAA and adjuvant, whereas mock-treated GAA-KO mice mounted vigorous T cell proliferation. Unlike AAV-LSPhGAA, AAV-CBhGAA induced selective cytokine and chemokine expression in liver and spleen after the immune challenge. AAV-CBhGAA transduced dendritic cells and expressed high-level GAA, whereas AAV-LSPhGAA failed to express GAA in dendritic cells. The level of transduction in liver was much higher after dual AAV8 vector administration at 18 weeks, in comparison with either vector alone. Dual vector administration failed to provoke antibody formation in response to GAA expression with AAV-CBhGAA; however, hepatic-restricted expression from dual vector expression did not prevent antibody formation after a strong immune challenge with GAA and adjuvant. The relevance of immune tolerance to gene therapy in Pompe disease indicates that hepatic expression might best be combined with nonhepatic expression, achieving the benefits of ubiquitous expression in addition to evading deleterious immune responses.Item Open Access Improved muscle function in a phase I/II clinical trial of albuterol in Pompe disease.(Molecular genetics and metabolism, 2020-02) Koeberl, Dwight D; Case, Laura E; Desai, Ankit; Smith, Edward C; Walters, Crista; Han, Sang-Oh; Thurberg, Beth L; Young, Sarah P; Bali, Deeksha; Kishnani, Priya SThis 24-week, Phase I/II, double-blind, randomized, placebo-controlled study investigated the safety and efficacy of extended-release albuterol in late-onset Pompe disease stably treated with enzyme replacement therapy at the standard dose for 4.9 (1.0-9.4) years and with no contraindications to intake of albuterol. Twelve of 13 participants completed the study. No serious adverse events were related to albuterol, and transient minor drug-related adverse events included muscle spasms and tremors. For the albuterol group, forced vital capacity in the supine position increased by 10% (p < .005), and forced expiratory volume in one second increased by 8% (p < .05); the six-minute walk test increased 25 m (p < .05; excluding one participant unable to complete muscle function testing); the Gross Motor Function Measure increased by 8% (p < .005) with the greatest increases in the Standing (18%; p < .05) and Walking, Running, and Jumping (11%; p < .005) subtests. No significant improvements would be expected in patients with late-onset Pompe disease who were stably treated with enzyme replacement therapy. The placebo group demonstrated no significant increases in performance on any measure. These data support a potential benefit of extended-release albuterol as adjunctive therapy in carefully selected patients with late-onset Pompe disease based on ability to take albuterol on enzyme replacement therapy (NCT01885936).Item Open Access Increased inspiratory and expiratory muscle strength following respiratory muscle strength training (RMST) in two patients with late-onset Pompe disease.(Molecular genetics and metabolism, 2011-11) Jones, Harrison N; Moss, Tronda; Edwards, Laurie; Kishnani, Priya SRespiratory muscle strength training (RMST) is an exercise-based intervention which targets respiratory muscle weakness. We implemented RMST in two patients with late-onset Pompe disease (LOPD), both who had received long-term enzyme replacement therapy and had severe respiratory weakness. Over 16-32 weeks, inspiratory muscle strength increased by 73-74%. Expiratory muscle strength increased 31-48% over 12-22 weeks. These findings suggest that RMST may increase respiratory muscle strength, even in the setting of LOPD and severe baseline weakness.Item Open Access Oropharyngeal Dysphagia in Infants and Children with Infantile Pompe Disease.(Dysphagia, 2009-09) Jones, HN; Muller, CW; Lin, M; Banugaria, SG; Case, LE; Li, JS; O'Grady, G; Heller, JH; Kishnani, PSPompe disease is a rare genetic progressive neuromuscular disorder. The most severe form, infantile Pompe disease, has historically resulted in early mortality, most commonly due to cardiorespiratory failure. Treatment with enzyme replacement therapy (ERT) using alglucosidase alfa (Myozyme((R))) has extended the lifespan of individuals with this disease. With the introduction of ERT and the resultant improved survival, dysphagia is being encountered clinically with increasing regularity though systematic data remain unavailable. We retrospectively studied the oropharyngeal swallowing of 13 infants and children with Pompe disease using videofluoroscopy before initiation of ERT, allowing for baseline swallow function to be established in an untreated cohort. Dysphagia was present in all 13 subjects, even in a participant only 15 days old. Oral stage signs were present in 77%, most frequently a weak suck in 69%. Pharyngeal stage signs were present in 100%, including a pharyngeal swallow delay in 92% and pharyngeal residue in 77%. Airway invasion was present in 76.9% of subjects, including penetration in five (38.46%) and silent aspiration in an additional five (38.46%). No relationship in the relative involvement of swallowing, gross motor function, and cardiac disease appeared to be present.Item Open Access Oropharyngeal dysphagia may occur in late-onset Pompe disease, implicating bulbar muscle involvement.(Neuromuscular disorders : NMD, 2013-04) Hobson-Webb, Lisa D; Jones, Harrison N; Kishnani, Priya SLate-onset Pompe disease (presenting after 12 months of age) often presents with limb-girdle and respiratory weakness, but oropharyngeal dysphagia has not been reported previously. A retrospective review of all late-onset Pompe disease patients evaluated in the neuromuscular clinic at Duke University Medical Center from 1999-2010 was performed. Twelve patients were identified and 3 had symptoms of oropharyngeal dysphagia. The medical record was reviewed, including the results of electromyography, videofluroscopic swallow examinations, and motor speech examination including instrumental assessment of lingual force with the Iowa Oral Performance Instrument. Oropharyngeal dysphagia was mild in two cases and severe in one. One of the two patients with mild severity demonstrated oral stage swallow signs; in the other, residual material was observed in the area of the cervical esophagus. In the patient with severe oropharyngeal dysphagia, both the oral and pharyngeal stages of swallowing were affected with penetration and aspiration documented. The degree of swallowing impairment appeared to correlate with overall physical strength and function. Oropharyngeal dysphagia may occur in patients with late-onset Pompe disease, implicating bulbar muscle involvement. Screening for symptoms of dysphagia may help reduce morbidity and mortality, while improving understanding of the late-onset Pompe disease phenotype. Further studies, including examination of the relationship between lingual weakness and oropharyngeal dysphagia, are warranted.Item Open Access Practical Recommendations for Diagnosis and Management of Respiratory Muscle Weakness in Late-Onset Pompe Disease.(International journal of molecular sciences, 2016-10) Boentert, Matthias; Prigent, Hélène; Várdi, Katalin; Jones, Harrison N; Mellies, Uwe; Simonds, Anita K; Wenninger, Stephan; Barrot Cortés, Emilia; Confalonieri, MarcoPompe 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.