title: Sarcoidosis and tuberculosis cytokine profiles: indistinguishable in bronchoalveolar lavage but different in blood.
abstract: BACKGROUND
  The clinical, radiological and pathological similarities between sarcoidosis and tuberculosis can make disease differentiation challenging. A complicating factor is that some cases of sarcoidosis may be initiated by mycobacteria. We hypothesised that immunological profiling might provide insight into a possible relationship between the diseases or allow us to distinguish between them.
  
  
  METHODS
  We analysed bronchoalveolar lavage (BAL) fluid in sarcoidosis (n = 18), tuberculosis (n = 12) and healthy volunteers (n = 16). We further investigated serum samples in the same groups; sarcoidosis (n = 40), tuberculosis (n = 15) and healthy volunteers (n = 40). A cross-sectional analysis of multiple cytokine profiles was performed and data used to discriminate between samples.
  
  
  RESULTS
  We found that BAL profiles were indistinguishable between both diseases and significantly different from healthy volunteers. In sera, tuberculosis patients had significantly lower levels of the Th2 cytokine interleukin-4 (IL-4) than those with sarcoidosis (p = 0.004). Additional serum differences allowed us to create a linear regression model for disease differentiation (within-sample accuracy 91%, cross-validation accuracy 73%).
  
  
  CONCLUSIONS
  These data warrant replication in independent cohorts to further develop and validate a serum cytokine signature that may be able to distinguish sarcoidosis from tuberculosis. Systemic Th2 cytokine differences between sarcoidosis and tuberculosis may also underly different disease outcomes to similar respiratory stimuli.
authors: Department of Respiratory Medicine, National Heart and Lung Institute, Imperial College London, London, United Kingdom.
authors: Muhunthan
authors: M
authors: Thillai
authors: Christian
authors: C
authors: Eberhardt
authors: Alex M
authors: AM
authors: Lewin
authors: Lee
authors: L
authors: Potiphar
authors: Suzie
authors: S
authors: Hingley-Wilson
authors: Saranya
authors: S
authors: Sridhar
authors: Jonathan
authors: J
authors: Macintyre
authors: Onn Min
authors: OM
authors: Kon
authors: Melissa
authors: M
authors: Wickremasinghe
authors: Athol
authors: A
authors: Wells
authors: Mark E
authors: ME
authors: Weeks
authors: Donald
authors: D
authors: Mitchell
authors: Ajit
authors: A
authors: Lalvani
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry* / Q000276:immunology; D016207:Cytokines / Q000097:blood*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017565:Sarcoidosis, Pulmonary / Q000097:blood* / Q000175:diagnosis* / Q000276:immunology; D014397:Tuberculosis, Pulmonary / Q000097:blood* / Q000175:diagnosis* / Q000276:immunology; D055815:Young Adult
chemical_list: D015415:Biomarkers; D016207:Cytokines