title: Up-regulation of L-selectin and E-selectin in hypersensitivity pneumonitis.
abstract: BACKGROUND
  Selectins are adhesion molecules that contribute to leukocyte recruitment into the tissue after an injury. Hypersensitivity pneumonitis (HP) is a lymphocytic alveolitis, and we hypothesized that the overexpression of selectins could play a role in this process.
  
  
  METHODS
  We studied 16 patients with HP and 7 healthy control subjects (HCs). Sera and BAL selectins and tumor necrosis factor-alpha were determined by enzyme-linked immunosorbent assay, and cellular lung localization was determined by immunohistochemistry. Additionally, BAL L-selectin, and L-selectin-bearing T-lymphocytes analyzed by flow cytometry were evaluated in HP patients and in exposed but asymptomatic subjects (EAS).
  
  
  METHODS
  Tertiary referral center and immunohistochemistry laboratory.
  
  
  RESULTS
  Raised levels of E-selectin (mean [+/- SD], 178.9 +/- 30.5 vs 59.4 +/- 4.7 ng/mL, respectively; p < 0.001) and P-selectin (mean, 232.6 +/- 29.9 vs 67.6 +/- 14.2 ng/mL, respectively; p < 0.001) were detected in HP patient sera compared to control subjects, while L-selectin levels showed no differences between groups. Conversely, HP patients displayed a significant increase in levels of L-selectin found in BAL fluid compared with both HCs and EAS (11.0 +/- 1.7 vs 6.9 +/- 0.43 and 3.1 +/- 0.5 ng/mL, respectively; p < 0.05). The levels of E-selectin found in BAL fluid were similar in patients from both groups, and P-selectin was not detected. Percentage of CD3+CD62 L+ lymphocytes was lower in HP patients compared with EAS (2.33 +/- 0.8 vs 4.31 +/- 2.4, respectively; p = 0.05). By immunohistochemistry, L-selectin was detected in interstitial macrophages and polymorphonuclear cells, and E-selectin was detected in endothelial cells.
  
  
  CONCLUSIONS
  These findings demonstrate that L-selectin and E-selectin are up-regulated during the development of HP, suggesting that they may contribute to the increased traffic of lung inflammatory cells.
authors.affiliation: Instituto Nacional de Enfermedades Respiratorias, Tlalpan 4502, México DF, México.
authors.forename: Carmen
authors.initials: C
authors.lastname: Navarro
authors.forename: Felipe
authors.initials: F
authors.lastname: Mendoza
authors.forename: Lourdes
authors.initials: L
authors.lastname: Barrera
authors.forename: Lourdes
authors.initials: L
authors.lastname: Segura-Valdez
authors.forename: Miguel
authors.initials: M
authors.lastname: Gaxiola
authors.forename: Ignacio
authors.initials: I
authors.lastname: Páramo
authors.forename: Moisés
authors.initials: M
authors.lastname: Selman
mesh_terms: D000328:Adult; D000542:Alveolitis, Extrinsic Allergic / Q000097:blood*; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry; D019040:E-Selectin / Q000502:physiology*; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D019041:L-Selectin / Q000502:physiology*; D008264:Macrophages / Q000737:chemistry; D008875:Middle Aged; D009504:Neutrophils / Q000737:chemistry; D014409:Tumor Necrosis Factor-alpha / Q000032:analysis; D015854:Up-Regulation / Q000502:physiology*
chemical_list: D019040:E-Selectin; D014409:Tumor Necrosis Factor-alpha; D019041:L-Selectin