title: Inflammatory mediators in nasal lavage among school-age children from urban and rural areas in São Paulo, Brazil.
abstract: BACKGROUND
  Some studies have shown that inflammatory processes in the nasal air passages may reflect or affect those in the lower airways. We decided to indirectly assess the inflammatory status of the nasal airways in two groups of children with different sensitization rates to aeroallergens.
  
  
  OBJECTIVE
  To compare the inflammatory activity in the nasal airways, through the determination of mediators in nasal lavage fluid in two distinct populations.
  
  
  METHODS
  Cross-sectional study.
  
  
  METHODS
  Two public elementary schools, one in an urban setting and the other in a rural setting of the State of São Paulo, Brazil.
  
  
  METHODS
  Two groups of 40 elementary school children with different sensitization rates to aeroallergens were formed. Samples of nasal lavage fluid were assessed for eosinophil cationic protein (ECP) and tryptase. Non-parametric tests were used for statistical analysis.
  
  
  RESULTS
  Significantly higher levels of ECP were observed among students living in the urban area than those in the rural area (p < 0.05). No significant difference in the tryptase levels was observed. Also, the urban children who were sensitized to aeroallergens presented higher levels of ECP in nasal mucosa than the non-sensitized children, while this difference was not observed among the rural children.
  
  
  CONCLUSIONS
  The lack of mast cell activity and increased eosinophil degranulation revealed a chronic inflammatory state in the nasal air passages. The higher eosinophil activity in the urban area, coinciding with higher sensitization to aeroallergens, suggests that there must be some factors in the urban area that can modulate airway inflammation by influencing the activation of inflammatory cells.
  
  
  CONCLUSIONS
  Our findings showed that there was no difference in the concentrations of tryptase in nasal lavage fluids between the two studied groups. However, the children from the urban area presented with higher concentrations of eosinophil cationic protein than did those from the rural area. Also, the urban children who were sensitized to aeroallergens presented with greater concentrations of eosinophil cationic protein in nasal mucosa than the non-sensitized children, while this difference was not observed among the rural children.
authors.affiliation: Escola Municipal de Ensino Fundamental João Carlos da Silva Borges, Moema, City of São Paulo, Brazil. cdgalvao@usp.br
authors.forename: Clóvis Eduardo Santos
authors.initials: CE
authors.lastname: Galvão
authors.forename: Paulo Hilário Nascimento
authors.initials: PH
authors.lastname: Saldiva
authors.forename: Jorge Elias
authors.initials: JE
authors.lastname: Kalil Filho
authors.forename: Fábio Fernandes Morato
authors.initials: FF
authors.lastname: Castro
mesh_terms: D000293:Adolescent; D000485:Allergens / Q000032:analysis* / Q000276:immunology; D001938:Brazil; D002648:Child; D003430:Cross-Sectional Studies; D047150:Eosinophil Cationic Protein / Q000032:analysis* / Q000276:immunology; D004804:Eosinophils / Q000737:chemistry; D005260:Female; D006801:Humans; D018836:Inflammation Mediators / Q000032:analysis* / Q000276:immunology; D008297:Male; D008407:Mast Cells / Q000737:chemistry; D017817:Nasal Lavage Fluid / Q000737:chemistry*; D012220:Rhinitis / Q000276:immunology; D012424:Rural Population; D012697:Serine Endopeptidases / Q000032:analysis* / Q000276:immunology; D053802:Tryptases; D014505:Urban Population
chemical_list: D000485:Allergens; D018836:Inflammation Mediators; D047150:Eosinophil Cationic Protein; D012697:Serine Endopeptidases; D053802:Tryptases