title: IgA rheumatoid factor correlates with changes in B and T lymphocyte subsets and disease manifestations in rheumatoid arthritis.
abstract: OBJECTIVE
  To analyze the relationship between lymphocyte subsets, different rheumatoid factor (RF) isotypes, and clinical features in patients with rheumatoid arthritis (RA).
  
  
  METHODS
  Patients with established RA (n = 95) were examined clinically and blood samples were collected for measurements of RF by ELISA and for analysis of lymphocyte subsets by flow cytometry.
  
  
  RESULTS
  IgA RF positive patients had more severe disease and higher prevalence of extraarticular manifestations than the other patients. Patients with elevated IgA RF had a higher percentage of CD5+ B cells and of CD4+CD45RO+ T cells compared to the other patients with RA or controls. High percentage of CD4+CD45RO+ T cells was also significantly associated with extraarticular manifestations. Patients with the sicca syndrome had significantly higher ratio of CD5+ B cells than patients without or with other types of extraarticular manifestations.
  
  
  CONCLUSIONS
  Different disease manifestations in RA may be associated not only with certain RF isotypes and RF isotype combinations but also with changes in lymphocyte subsets in the blood. The relative increase of CD4+CD45RO+ T cells in the blood of IgA RF positive patients with RA might reflect preferential recruitment of CD8+CD45RO+ T cells to inflammatory sites.
authors.affiliation: Department of Immunology, National University Hospital, Reykjavík, Iceland.
authors.forename: S
authors.initials: S
authors.lastname: Arinbjarnarson
authors.forename: T
authors.initials: T
authors.lastname: Jonsson
authors.forename: K
authors.initials: K
authors.lastname: Steinsson
authors.forename: A
authors.initials: A
authors.lastname: Sigfusson
authors.forename: H
authors.initials: H
authors.lastname: Jonsson
authors.forename: A
authors.initials: A
authors.lastname: Geirsson
authors.forename: J
authors.initials: J
authors.lastname: Thorsteinsson
authors.forename: H
authors.initials: H
authors.lastname: Valdimarsson
mesh_terms: D000328:Adult; D000368:Aged; D015703:Antigens, CD / Q000276:immunology; D001172:Arthritis, Rheumatoid / Q000209:etiology / Q000276:immunology*; D016175:B-Lymphocyte Subsets / Q000276:immunology*; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007070:Immunoglobulin A / Q000032:analysis*; D007132:Immunoglobulin Isotypes / Q000032:analysis; D008297:Male; D008875:Middle Aged; D012217:Rheumatoid Factor / Q000276:immunology*; D016176:T-Lymphocyte Subsets / Q000276:immunology*
chemical_list: D015703:Antigens, CD; D007070:Immunoglobulin A; D007132:Immunoglobulin Isotypes; D012217:Rheumatoid Factor