title: Dual analysis for mycobacteria and propionibacteria in sarcoidosis BAL.
abstract: OBJECTIVE
  Sarcoidosis is a non-caseating granulomatous disease for which a role for infectious antigens continues to strengthen. Recent studies have reported molecular evidence of mycobacteria or propionibacteria. We assessed for immune responses against mycobacterial and propionibacterial antigens in sarcoidosis bronchoalveolar lavage (BAL) using flow cytometry, and localized signals consistent with microbial antigens with sarcoidosis specimens, using matrix-assisted laser desorption ionization imaging mass spectrometry (MALDI-IMS).
  
  
  METHODS
  BAL cells from 27 sarcoidosis, 14 PPD- controls, and 9 subjects with nontuberculosis mycobacterial (NTM) infections were analyzed for production of IFN-γ after stimulation with mycobacterial ESAT-6 and Propionibacterium acnes proteins. To complement the immunological data, MALDI-IMS was performed to localize ESAT-6 and Propionibacterium acnes signals within sarcoidosis and control specimens.
  
  
  RESULTS
  CD4+ immunologic analysis for mycobacteria was positive in 17/27 sarcoidosis subjects, compared to 2/14 PPD- subjects, and 5/9 NTM subjects (p = 0.008 and p = 0.71 respectively, Fisher's exact test). There was no significant difference for recognition of P. acnes, which occurred only in sarcoidosis subjects that also recognized ESAT-6. Similar results were also observed for the CD8+ immunologic analysis. MALDI-IMS localized signals consistent with ESAT-6 only within sites of granulomatous inflammation, whereas P. acnes signals were distributed throughout the specimen.
  
  
  CONCLUSIONS
  MALDI-IMS localizes signals consistent with ESAT-6 to sarcoidosis granulomas, whereas no specific localization of P. acnes signals is detected. Immune responses against both mycobacterial and P. acnes are present within sarcoidosis BAL, but only mycobacterial signals are distinct from disease controls. These immunologic and molecular investigations support further investigation of the microbial community within sarcoidosis granulomas.
authors.affiliation: Department of Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, TN 37232-2363, USA. Kyra.Richter@vanderbilt.edu
authors.forename: Kyra A
authors.initials: KA
authors.lastname: Oswald-Richter
authors.forename: Dia C
authors.initials: DC
authors.lastname: Beachboard
authors.forename: Erin H
authors.initials: EH
authors.lastname: Seeley
authors.forename: Susamma
authors.initials: S
authors.lastname: Abraham
authors.forename: Bryan E
authors.initials: BE
authors.lastname: Shepherd
authors.forename: Cathy A
authors.initials: CA
authors.lastname: Jenkins
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Culver
authors.forename: Richard M
authors.initials: RM
authors.lastname: Caprioli
authors.forename: Wonder P
authors.initials: WP
authors.lastname: Drake
mesh_terms: D000328:Adult; D000368:Aged; D000942:Antigens, Bacterial / Q000276:immunology*; D001426:Bacterial Proteins / Q000276:immunology*; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology / Q000276:immunology*; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D004768:Enterotoxins / Q000494:pharmacology; D005260:Female; D006801:Humans; D007371:Interferon-gamma / Q000276:immunology; D008297:Male; D008875:Middle Aged; D009161:Mycobacterium / Q000276:immunology*; D009164:Mycobacterium Infections / Q000276:immunology; D010455:Peptides / Q000276:immunology; D011425:Propionibacterium acnes / Q000276:immunology*; D012507:Sarcoidosis / Q000276:immunology* / Q000382:microbiology; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D055815:Young Adult
chemical_list: D000942:Antigens, Bacterial; D001426:Bacterial Proteins; C093276:ESAT-6 protein, Mycobacterium tuberculosis; D004768:Enterotoxins; D010455:Peptides; C031818:enterotoxin B, staphylococcal; D007371:Interferon-gamma