title: Regulatory B cells are inversely associated with disease activity in rheumatoid arthritis.
abstract: OBJECTIVE
  The function of regulatory B lymphocytes is known to be abnormal in inflammatory diseases. However, a recent study indicates that IL-10+ B cells seem to be expanded in rheumatoid arthritis (RA). Therefore, the state of IL-10+ B cells in the peripheral blood from RA patients and healthy controls were investigated.
  
  
  METHODS
  CD19+ cells in peripheral blood mononuclear cells were purified from blood samples of RA patients and age and gender-matched healthy controls, and stimulated with CD40 ligand and CpG for 48 hours. Then, intracellular IL-10 in CD19+ cells was analyzed using flow cytometry.
  
  
  RESULTS
  There was no significant difference in the proportion of IL-10+ B cells between 10 RA patients and 10 healthy controls (RA, 0.300±0.07 vs. healthy control 0.459±0.07, p=0.114). The proportion of induced IL-10+ B cells to total B cells in RA patients was significantly higher than those in controls (RA, 4.44±3.44% vs. healthy control 2.44±1.64%, p=0.033). However, the proportion of IL-10+ B cells to total B cells correlated negatively with disease activity in RA patients (r=-0.398, p=0.040). Erythrocyte sedimentation rate or C-reactive protein or medication was not associated with the proportion of IL-10+ B cells.
  
  
  CONCLUSIONS
  The proportion of induced IL-10+ B cell increased in RA patients compared to healthy control, however, negatively correlated with disease activity in RA.
authors.affiliation: Department of Internal Medicine, Chungnam National University School of Medicine, Daejeon, Korea.
authors.forename: Jinhyun
authors.initials: J
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Chungnam National University School of Medicine, Daejeon, Korea.
authors.forename: Hyun Ji
authors.initials: HJ
authors.lastname: Lee
authors.affiliation: Department of Internal Medicine, Chungnam National University School of Medicine, Daejeon, Korea.
authors.forename: In Seol
authors.initials: IS
authors.lastname: Yoo
authors.affiliation: Department of Internal Medicine, Chungnam National University School of Medicine, Daejeon, Korea.
authors.forename: Seong Wook
authors.initials: SW
authors.lastname: Kang
authors.affiliation: Department of Paediatrics, Chungnam National University School of Medicine, Daejeon, Korea. immlee@cnu.ac.kr.
authors.forename: Jae Ho
authors.initials: JH
authors.lastname: Lee
mesh_terms: D000328:Adult; D000368:Aged; D018941:Antigens, CD19 / Q000378:metabolism; D001172:Arthritis, Rheumatoid / Q000097:blood / Q000276:immunology* / Q000473:pathology; D060151:B-Lymphocytes, Regulatory / Q000378:metabolism / Q000502:physiology*; D015415:Biomarkers / Q000097:blood; D005260:Female; D006801:Humans; D016753:Interleukin-10 / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D012720:Severity of Illness Index
chemical_list: D018941:Antigens, CD19; D015415:Biomarkers; D016753:Interleukin-10
keywords: Regulatory B lymphocytes; interleukin-10; rheumatoid arthritis