title: Characterization of pulmonary function impairments in patients with mucopolysaccharidoses--changes with age and treatment.
abstract: BACKGROUND
  The mucopolysaccharidoses (MPS) comprise a group of inherited lysosomal storage disorders characterized by deficiencies in enzymes catalyzing the degradation of glycosaminoglycans. Impairment of pulmonary function is an important health problem for patients with MPS. However, there are few published reports on the prevalence and severity of pulmonary dysfunction in relation to age and treatment in this disorder.
  
  
  METHODS
  To evaluate pulmonary function in patients with MPS, we performed spirometry in 35 patients (22 males and 13 females; 1 with MPS I, 12 with MPS II, 16 with MPS IVA, and 6 with MPS VI; mean age, 14.6 ± 5.9 years; age range, 6.4 years to 33 years). Forced vital capacity (FVC), forced expired volume in 1 sec (FEV1), FEV1 to FVC ratio (FEV1/FVC), peak expiratory flow (PEF), and mean forced expiratory flow during the middle half of FVC (FEF25-75% ) were measured.
  
  
  RESULTS
  Mean FVC, FEV1 , PEF, and FEF25-75% were 74.2%, 73.9%, 64.7%, and 37.1% of the predicted values, respectively. By spirometric classification, 32 patients (91%) had small airway disease (FEF25-75%  < 65%), 17 (48%) had restrictive lung disease, and 3 (9%) had obstructive lung disease. Percent predicted FVC, FEV1 , and PEF, as well as FEV1 /FVC, were all negatively correlated with age (P < 0.01), such that pubertal and post-pubertal patients had significantly lower values than younger patients. Of eight attenuated MPS II and VI patients who underwent follow-up pulmonary function testing after receiving enzyme replacement therapy (ERT) for 1.5-7.4 years, six showed improvements in % predicted FVC and five improved in % predicted FEV1 .
  
  
  CONCLUSIONS
  Our additional characterization of the types and prevalence of pulmonary function abnormalities seen in MPS patients should be useful for clinical care.
authors: Department of Pediatrics, Mackay Memorial Hospital, Taipei, Taiwan; Department of Medical Research, Mackay Memorial Hospital, Taipei, Taiwan; Department of Medicine, Mackay Medical College, New Taipei City, Taiwan; Department of Early Infant Care and Education, Mackay Medicine, Nursing and Management College, Taipei, Taiwan; Department of Infant and Child Care, National Taipei University of Nursing and Health Sciences, Taipei, Taiwan.
authors: Shuan-Pei
authors: SP
authors: Lin
authors: Shou-Chuan
authors: SC
authors: Shih
authors: Chih-Kuang
authors: CK
authors: Chuang
authors: Kuo-Sheng
authors: KS
authors: Lee
authors: Ming-Ren
authors: MR
authors: Chen
authors: Dau-Ming
authors: DM
authors: Niu
authors: Pao Chin
authors: PC
authors: Chiu
authors: Shio Jean
authors: SJ
authors: Lin
authors: Hsiang-Yu
authors: HY
authors: Lin
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D002648:Child; D018450:Disease Progression; D056947:Enzyme Replacement Therapy / Q000379:methods*; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D008168:Lung / Q000503:physiopathology*; D008171:Lung Diseases / Q000209:etiology / Q000503:physiopathology*; D008173:Lung Diseases, Obstructive / Q000209:etiology / Q000503:physiopathology; D008297:Male; D008450:Maximal Midexpiratory Flow Rate; D009083:Mucopolysaccharidoses / Q000150:complications / Q000188:drug therapy / Q000503:physiopathology*; D008059:Mucopolysaccharidosis I / Q000150:complications / Q000188:drug therapy / Q000503:physiopathology; D016532:Mucopolysaccharidosis II / Q000150:complications / Q000188:drug therapy / Q000503:physiopathology; D009084:Mucopolysaccharidosis III / Q000150:complications / Q000188:drug therapy / Q000503:physiopathology; D009085:Mucopolysaccharidosis IV / Q000150:complications / Q000188:drug therapy / Q000503:physiopathology; D009087:Mucopolysaccharidosis VI / Q000150:complications / Q000188:drug therapy / Q000503:physiopathology; D010366:Peak Expiratory Flow Rate; D012129:Respiratory Function Tests; D012720:Severity of Illness Index; D013147:Spirometry; D016896:Treatment Outcome; D014797:Vital Capacity / Q000502:physiology; D055815:Young Adult
keywords: enzyme replacement therapy; glycosaminoglycans; mucopolysaccharidoses; pulmonary function; spirometry