title: Discrepancy between cytokine production from peripheral blood mononuclear cells and nasal secretions among infants with acute bronchiolitis.
abstract: BACKGROUND
  Many studies have measured cytokine production derived from peripheral blood mononuclear cells (PBMCs) to evaluate the immune response in acute bronchiolitis (AB), but no previous reports have examined the association between PBMC release of cytokines and concomitant airway immune response.
  
  
  OBJECTIVE
  To determine whether interferon-gamma (IFN-gamma), interleukin 4 (IL-4), and IL-10 levels from PBMCs are associated with concurrent cytokine release in the airways of infants with AB.
  
  
  METHODS
  Infants with acute viral-associated first episode of wheezing who required hospitalization between May and September 2002 were recruited. Nasopharyngeal aspirates (NPAs) and PBMC samples were collected simultaneously. The concentrations of IFN-gamma, IL-4, and IL-10 in NPA and PBMC supernatants were determined by enzyme-linked immunosorbent assay.
  
  
  RESULTS
  Twenty infants with AB were enrolled in the study of whom 17 (85%) had positive NPA immunofluorescence results for viral detection and respiratory syncytial virus. Median total cell count and viability from NPA samples were 2.2 x 10(6) cells/mL (SD, 1.7 cells/mL) and 92% (SD, 6.0%), respectively. There was a significant correlation between IL-4 levels from NPA and PBMC samples (r = 0.5, P = .02); however, we did not find an association between IFN-gamma and IL-10 levels.
  
  
  CONCLUSIONS
  Cytokines produced by in vitro PBMCs may not necessarily reflect the concurrent cytokine pattern production at the mucosal surface in the respiratory tract of infants with AB. Further studies are required to determine whether peripheral blood is a reliable sample for airway inflammation evaluation and to explain the discrepancies of cytokine productions found in this study.
authors.affiliation: Department of Pediatrics, Instituto de Pesquisas Biomédicas da PUCRS, Porto Alegre, Brazil. pmpitrez@pucrs.br
authors.forename: Paulo Márcio Condessa
authors.initials: PM
authors.lastname: Pitrez
authors.forename: Daniela
authors.initials: D
authors.lastname: Ponzi
authors.forename: Denise Cantarelli
authors.initials: DC
authors.lastname: Machado
authors.forename: Moisés Evandro
authors.initials: ME
authors.lastname: Bauer
authors.forename: Marcus Herbert
authors.initials: MH
authors.lastname: Jones
authors.forename: Renato Tetelbom
authors.initials: RT
authors.lastname: Stein
mesh_terms: D001988:Bronchiolitis / Q000276:immunology*; D002478:Cells, Cultured; D016207:Cytokines / Q000096:biosynthesis*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007223:Infant; D007963:Leukocytes, Mononuclear / Q000276:immunology*; D008297:Male; D017817:Nasal Lavage Fluid / Q000276:immunology*
chemical_list: D016207:Cytokines