title: Quantitative computed tomography for enzyme replacement therapy in Pompe disease.
abstract: OBJECTIVE
  Pompe disease is an autosomal recessive disorder caused by deficiency of the lysosomal enzyme, acid alpha-glucosidase (GAA). To the best of our knowledge, no studies have reported the results of systematic and sequential CT analyses before and during ERT. In this study we have treated three patients with late onset Pompe disease by ERT, and investigated the efficacy of treatment by computed tomography number.
  
  
  METHODS
  We measured the serial changes in the computed tomography (CT) number of multiple organs in three patients with late onset of Pompe disease during 24 months of enzyme replacement therapy (ERT).
  
  
  RESULTS
  Before treatment, the liver and muscle CT numbers were higher in these patients than in the controls. The liver CT number decreased after performing ERT. Furthermore, the urinary glucose tetrasaccharide levels, a biomarker of glycogen accumulation, were elevated before ERT and reduced thereafter.
  
  
  CONCLUSIONS
  The findings in these cases suggest that the elevation of the liver CT number represents glycogen accumulation in the liver and that the analysis of the liver CT number is therefore a useful tool for assessing the efficacy of ERT.
authors.affiliation: Department of Pediatrics, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima City, Kagoshima, Japan. yonee-myz@umin.ac.jp
authors.forename: Chihiro
authors.initials: C
authors.lastname: Yonee
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Toyoshima
authors.forename: Sarah P
authors.initials: SP
authors.lastname: Young
authors.forename: Shinsuke
authors.initials: S
authors.lastname: Maruyama
authors.forename: Itsuro
authors.initials: I
authors.lastname: Higuchi
authors.forename: Aya
authors.initials: A
authors.lastname: Narita
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Maegaki
authors.forename: Eiji
authors.initials: E
authors.lastname: Nanba
authors.forename: Kousaku
authors.initials: K
authors.lastname: Ohno
authors.forename: Yoshifumi
authors.initials: Y
authors.lastname: Kawano
mesh_terms: D002675:Child, Preschool; D056947:Enzyme Replacement Therapy / Q000379:methods*; D005260:Female; D006003:Glycogen / Q000652:urine; D006009:Glycogen Storage Disease Type II / Q000175:diagnosis / Q000188:drug therapy* / Q000201:enzymology*; D006801:Humans; D008099:Liver / Q000201:enzymology; D018482:Muscle, Skeletal / Q000201:enzymology; D009844:Oligosaccharides / Q000652:urine; D014057:Tomography, X-Ray Computed / Q000379:methods; D000520:alpha-Glucosidases / Q000627:therapeutic use
chemical_list: D009844:Oligosaccharides; C033620:glucose tetrasaccharide; D006003:Glycogen; D000520:alpha-Glucosidases