title: Integrin α E β 7 (CD103) expression in bronchoalveolar lymphocytes of patients with hypersensitivity pneumonitis.
abstract: OBJECTIVE
  CD4+/CD8+ ratio in bronchoalveolar lavage fluid (BALF) often retrieves contradictory findings when used for diagnosis of sarcoidosis and hypersensitivity pneumonitis (HP), so CD103+ has been investigated as a possible differential marker. We aimed to compare CD103+ expression in BALF T-lymphocytes between patients with HP, sarcoidosis and other interstitial lung diseases (ILD).
  
  
  METHODS
  An observational study carried out over a 2-year period included consecutive patients with suspected ILD who underwent BALF as part of their initial diagnostic work-up; CD103+ expression on BALF T-lymphocytes was evaluated. After a final diagnosis established according to international criteria, three patient subgroups-HP, ILD (which included idiopathic interstitial pneumonia and connective tissue disease-associated lung disorders) and sarcoidosis-were considered for further analysis.
  
  
  RESULTS
  A total of 77 subjects were enrolled, 20 with HP, 16 with other ILD and 41 with sarcoidosis. A significantly higher number of CD4+ CD103+ and CD8+ CD103+ lymphocytes were found in HP patients. Among patients with sarcoidosis, 12 (29.3 %) presented a BALF CD4+/CD8+ <3.5, all of them with histological confirmation. Compared to these patients, also statistically significant higher CD4+ CD103+ counts in HP patients were observed (p = 0.007). Among HP patients, although bird fanciers (n = 14) presented higher percentages of both CD4+ CD103+ and CD8+ CD103+ T-lymphocytes than those with work-related HP (n = 5), the differences did not reach statistical significance.
  
  
  CONCLUSIONS
  Patients with HP present significantly higher counts of CD103+ T-lymphocytes in BALF, both in the CD4+ and CD8+ subsets, when compared to sarcoidosis, even with sarcoidosis subgroup presenting a BALF CD4+/CD8+ <3.5. The expression of CD103 may help in the interpretation of BALF data in these diffuse granulomatous lung disorders.
authors.affiliation: Serviço e Laboratório de Imunologia, Faculdade de Medicina, Universidade do Porto, Alameda Prof Hernâni Monteiro, 4200-319, Porto, Portugal, marianafercouto@gmail.com.
authors.forename: Mariana
authors.initials: M
authors.lastname: Couto
authors.forename: Carmo
authors.initials: C
authors.lastname: Palmares
authors.forename: Marília
authors.initials: M
authors.lastname: Beltrão
authors.forename: Sofia
authors.initials: S
authors.lastname: Neves
authors.forename: Patrícia
authors.initials: P
authors.lastname: Mota
authors.forename: António
authors.initials: A
authors.lastname: Morais
authors.forename: Luís
authors.initials: L
authors.lastname: Delgado
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000542:Alveolitis, Extrinsic Allergic / Q000097:blood* / Q000175:diagnosis / Q000453:epidemiology / Q000276:immunology*; D015703:Antigens, CD / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D018893:Bronchoalveolar Lavage; D002648:Child; D005260:Female; D006801:Humans; D039001:Integrin alpha Chains / Q000097:blood*; D017563:Lung Diseases, Interstitial / Q000097:blood / Q000453:epidemiology / Q000276:immunology / Q000473:pathology; D008214:Lymphocytes; D008297:Male; D008875:Middle Aged; D017565:Sarcoidosis, Pulmonary; D012907:Smoking / Q000453:epidemiology; D055815:Young Adult
chemical_list: D015703:Antigens, CD; D015415:Biomarkers; D039001:Integrin alpha Chains; C091367:alpha E integrins