title: Inflammatory patterns in asthmatic children based on alveolar nitric oxide determination.
abstract: BACKGROUND
  Nitric oxide (NO) levels can be measured at proximal (maximum airway NO flux [J'aw(NO)]) and distal (alveolar NO concentration [C(ANO)]) levels. Four inflammatory patterns have been described in asthmatic individuals, although their relevance has not been well established. The objective was to determine J'aw(NO) and C(ANO) in order to establish four inflammatory categories in asthmatics.
  
  
  METHODS
  Cross-sectional study of a sample consisting of healthy and asthmatic children. Exhaled NO was determined at multiple flows. J'aw(NO) and C(ANO) were obtained according to the two-compartment model. The asthma control questionnaire (ACQ) and spirometry were administered to asthmatic children. Patients were categorized as type I (normal J'aw(NO) and C(ANO)), type II (elevated J'aw(NO) and normal C(ANO)), type III (elevated J'aw(NO) and C(ANO)) and type IV (normal J'aw(NO) and elevated C(ANO)). Correlation between FE(NO,50), J'aw(NO) and C(ANO) was analyzed using Spearman's R Correlation Test. Analysis of variance and paired comparisons were performed using the Bonferroni correction.
  
  
  RESULTS
  One hundred sixty-two children were studied, of whom 49 (32.23%) were healthy controls and 103 (67.76%) asthmatics. In the control subjects, FE(NO,50) (ppb)(median and range) was 11.5 (1.6 to 27.3), J'aw(NO) (pl/s) was 516 (98.3 to 1470) and C(ANO) (ppb) was 2.2 (0.1 to 4.5). Forty-four (42.7%) of the asthmatic participants were categorized as type I, 41 (39.8%) as type II, 14 (13.5%) as type III and 4 (3.88%) as type IV. Good correlation was observed between J'aw(NO) and FE(NO,50) (r=0.97). There was no association between J'aw(NO) and C(ANO). FEV1/FVC decreased significantly in type III (mean 79.8±7.5). Morbidity was significantly higher in types III and IV.
  
  
  CONCLUSIONS
  Normal values obtained are similar to those previously reported. Asthmatics with high C(ANO) showed higher morbidity. No correlation was found between proximal and distal inflammation.
authors.affiliation: Sección de Neumología Infantil, Hospital Universitario Donostia, San Sebastián, Guipúzcoa, España.
authors.forename: Paula
authors.initials: P
authors.lastname: Corcuera-Elosegui
authors.affiliation: Sección de Neumología Infantil, Hospital Universitario Donostia, San Sebastián, Guipúzcoa, España; Departamento de Pediatría, Universidad del País Vasco (UPV/EHU), San Sebastián, Guipúzcoa, España. Electronic address: osardon@gmail.com.
authors.forename: Olaia
authors.initials: O
authors.lastname: Sardón-Prado
authors.affiliation: Sección de Neumología Infantil, Hospital Universitario Donostia, San Sebastián, Guipúzcoa, España.
authors.forename: Ane
authors.initials: A
authors.lastname: Aldasoro-Ruiz
authors.affiliation: Sección de Neumología Infantil, Hospital Universitario Donostia, San Sebastián, Guipúzcoa, España; Departamento de Pediatría, Universidad del País Vasco (UPV/EHU), San Sebastián, Guipúzcoa, España.
authors.forename: Javier
authors.initials: J
authors.lastname: Korta-Murua
authors.affiliation: Sección de Neumología Infantil, Hospital Universitario Donostia, San Sebastián, Guipúzcoa, España.
authors.forename: Javier
authors.initials: J
authors.lastname: Mintegui-Aramburu
authors.affiliation: Unidad de Epidemiología (CIBER-ESP), Hospital Universitario Donostia, San Sebastián, Guipúzcoa, España.
authors.forename: José I
authors.initials: JI
authors.lastname: Emparanza-Knorr
authors.affiliation: Sección de Neumología Infantil, Hospital Universitario Donostia, San Sebastián, Guipúzcoa, España; Departamento de Pediatría, Universidad del País Vasco (UPV/EHU), San Sebastián, Guipúzcoa, España; Centro de Investigación Biomédica en Red, Enfermedades Respiratorias (CIBERES), San Sebastián, Guipúzcoa, España.
authors.forename: Eduardo G
authors.initials: EG
authors.lastname: Pérez-Yarza
mesh_terms: D001249:Asthma / Q000145:classification / Q000378:metabolism / Q000473:pathology* / Q000503:physiopathology; D001944:Breath Tests; D016022:Case-Control Studies; D002648:Child; D015897:Comorbidity; D003430:Cross-Sectional Studies; D003876:Dermatitis, Atopic / Q000453:epidemiology; D005260:Female; D005512:Food Hypersensitivity / Q000453:epidemiology; D006801:Humans; D007249:Inflammation / Q000145:classification*; D008297:Male; D009569:Nitric Oxide / Q000032:analysis*; D011650:Pulmonary Alveoli / Q000737:chemistry*; D012221:Rhinitis, Allergic, Perennial / Q000453:epidemiology; D006255:Rhinitis, Allergic, Seasonal / Q000453:epidemiology; D013147:Spirometry; D011795:Surveys and Questionnaires
chemical_list: D009569:Nitric Oxide
keywords: Alveolar nitric oxide; Asma; Asthma; Categorías inflamatorias; Children; Inflammatory categories; Niños; Óxido nítrico alveolar