title: Exhaled nitric oxide: Not associated with asthma, symptoms, or spirometry in children with sickle cell anemia.
abstract: The significance of fractional exhaled nitric oxide (Feno) levels in children with sickle cell anemia (SCA) is unclear, but increased levels can be associated with features of asthma and thus increased morbidity.
  
  
  
  We sought to determine factors associated with Feno and whether Feno levels are associated with increased rates of acute chest syndrome (ACS) and pain.
  
  
  
  All participants had SCA, were part of the prospective observational Sleep and Asthma Cohort study, and had the following assessments: Feno levels, spirometry, blood samples analyzed for hemoglobin, white blood cell counts, eosinophil counts and total serum IgE levels, questionnaires about child medical and family history, and review of medical records.
  
  
  
  The analytic sample included 131 children with SCA (median age, 11.2 years; age range, 6-18 years) followed for a mean of 16.2 years, including a mean of 5.1 years after baseline Feno data measurements. In multivariable analyses higher Feno levels were associated with ln(IgE) levels (P < .001) and the highest quartile of peripheral eosinophil counts (P = .03) but not wheezing symptoms, baseline spirometric indices, or response to bronchodilator. Multivariable analyses identified that the incident rate of ACS was associated with ln(Feno) levels (P = .03), as well as male sex (P = .025), wheezing causing shortness of breath (P = .002), and ACS at less than 4 years of age (P < .001). Feno levels were not associated with future pain episodes.
  
  
  
  Steady-state Feno levels were not associated with an asthma diagnosis, wheezing symptoms, lung function measures, or prior sickle cell morbidity but were associated with markers of atopy and increased risk of future ACS events.
authors: Department of Pediatrics, Boston University School of Medicine, Boston, Mass. Electronic address: robyn.cohen@bmc.org.
authors: Robyn T
authors: RT
authors: Cohen
authors: Rodeghier Consultants, Chicago, Ill.
authors: Mark
authors: M
authors: Rodeghier
authors: Neurosciences Unit, University College London, Institute of Child Health, London, United Kingdom.
authors: Fenella J
authors: FJ
authors: Kirkham
authors: Department of Pediatrics, Case Western Reserve University School of Medicine, Cleveland, Ohio.
authors: Carol L
authors: CL
authors: Rosen
authors: Portex Respiratory Unit, University College London, Institute of Child Health, London, United Kingdom.
authors: Jane
authors: J
authors: Kirkby
authors: Department of Pediatrics, Vanderbilt University School of Medicine, Nashville, Tenn.
authors: Michael R
authors: MR
authors: DeBaun
authors: Division of Allergy, Immunology, and Pulmonary Medicine, Department of Pediatrics, Washington University School of Medicine, St Louis, Mo.
authors: Robert C
authors: RC
authors: Strunk
mesh_terms: D000293:Adolescent; D000485:Allergens / Q000276:immunology; D000755:Anemia, Sickle Cell / Q000276:immunology / Q000378:metabolism* / Q000503:physiopathology; D001249:Asthma / Q000276:immunology / Q000378:metabolism* / Q000503:physiopathology; D001944:Breath Tests; D002648:Child; D045853:Exhalation; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D008297:Male; D009569:Nitric Oxide / Q000378:metabolism*; D012882:Skin Tests; D013147:Spirometry; D014797:Vital Capacity
chemical_list: D000485:Allergens; D009569:Nitric Oxide
keywords: Sickle cell disease; acute chest syndrome; airway inflammation; asthma; exhaled nitric oxide