title: Active chronic sarcoidosis is characterized by increased transitional blood B cells, increased IL-10-producing regulatory B cells and high BAFF levels.
abstract: BACKGROUND
  Sarcoidosis is a multisystemic disease of unknown etiology characterized by a disproportionate Th1 granulomatous immune response in the organs involved. Plasmatic hypergammaglobulinemia and B cell accumulation in granulomatous lesions suggest the possible role of humoral immune responses in the pathogenesis of sarcoidosis. The purpose of this study is to describe B cell peripheral compartment in sarcoidosis.
  
  
  RESULTS
  We analyzed blood B cell subsets and BAFF levels in 33 patients with chronic sarcoidosis (active sarcoidosis n = 18; inactive sarcoidosis n = 15) and 18 healthy donors. Active chronic sarcoidosis patients had significantly less circulating memory B cells (p<0.01), more transitional (p<0.01) and increased numbers of IL-10-producing regulatory B cells (p<0.05) compared with healthy donors and patients with inactive sarcoidosis. BAFF serum levels were significantly higher in patients with active sarcoidosis (p<0.01 versus healthy donors and inactive sarcoidosis patients) and strongly correlated with serum hypergammaglobulinemia (r = 0.53, p<0.01) and angiotensin converting enzyme levels (r = 0.61, p = <0.01).
  
  
  CONCLUSIONS
  These data show that there is an altered B cell homeostasis in active sarcoidosis and suggest BAFF antagonist drugs as potential new treatments of this disease.
authors.affiliation: INSERM U976, Paris, France.
authors.forename: Anne
authors.initials: A
authors.lastname: Saussine
authors.forename: Abdellatif
authors.initials: A
authors.lastname: Tazi
authors.forename: Séverine
authors.initials: S
authors.lastname: Feuillet
authors.forename: Michel
authors.initials: M
authors.lastname: Rybojad
authors.forename: Caroline
authors.initials: C
authors.lastname: Juillard
authors.forename: Anne
authors.initials: A
authors.lastname: Bergeron
authors.forename: Valérie
authors.initials: V
authors.lastname: Dessirier
authors.forename: Fatiha
authors.initials: F
authors.lastname: Bouhidel
authors.forename: Anne
authors.initials: A
authors.lastname: Janin
authors.forename: Armand
authors.initials: A
authors.lastname: Bensussan
authors.forename: Martine
authors.initials: M
authors.lastname: Bagot
authors.forename: Jean-David
authors.initials: JD
authors.lastname: Bouaziz
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D053264:B-Cell Activating Factor / Q000097:blood*; D060151:B-Lymphocytes, Regulatory / Q000166:cytology* / Q000378:metabolism*; D016022:Case-Control Studies; D002452:Cell Count; D002908:Chronic Disease; D005260:Female; D006099:Granuloma / Q000097:blood / Q000150:complications; D006801:Humans; D006942:Hypergammaglobulinemia / Q000150:complications; D016753:Interleukin-10 / Q000096:biosynthesis*; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D012507:Sarcoidosis / Q000097:blood* / Q000150:complications / Q000276:immunology*; D013997:Time Factors; D055815:Young Adult
chemical_list: D053264:B-Cell Activating Factor; C505719:TNFSF13B protein, human; D016753:Interleukin-10