title: X linked agammaglobulinaemia and rheumatoid arthritis.
abstract: BACKGROUND
  Much interest has been shown recently in the pathogenic role of B cells in rheumatoid arthritis (RA) owing to the marked clinical responses to anti-CD20 treatment in RA.
  
  
  METHODS
  A patient with X linked agammaglobulinaemia (XLA) presented with an erosive symmetric polyarthritis with histological features of RA, including formation of a destructive pannus. Furthermore, the patient developed subcutaneous nodules that were histologically indistinguishable from rheumatoid nodules. Surprisingly, lymphocytic infiltrates in both the synovium and nodule consisted almost exclusively of CD8+ T cells.
  
  
  CONCLUSIONS
  Although some peculiar B cell subsets have been described in patients with XLA, no B cell subsets could be demonstrated in synovial tissue or the subcutaneous nodule. This case illustrates that classical RA can develop in the absence of mature B cells.
authors.affiliation: Department of Rheumatology, University Hospital Gent, De Pintelaan 185, 9000 Gent, Belgium.
authors.forename: G
authors.initials: G
authors.lastname: Verbruggen
authors.forename: S
authors.initials: S
authors.lastname: De Backer
authors.forename: D
authors.initials: D
authors.lastname: Deforce
authors.forename: P
authors.initials: P
authors.lastname: Demetter
authors.forename: C
authors.initials: C
authors.lastname: Cuvelier
authors.forename: E
authors.initials: E
authors.lastname: Veys
authors.forename: D
authors.initials: D
authors.lastname: Elewaut
mesh_terms: D000361:Agammaglobulinemia / Q000235:genetics* / Q000276:immunology*; D001172:Arthritis, Rheumatoid / Q000000981:diagnostic imaging / Q000276:immunology* / Q000473:pathology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D017809:Fatal Outcome; D040181:Genetic Diseases, X-Linked / Q000000981:diagnostic imaging / Q000276:immunology* / Q000473:pathology; D006225:Hand / Q000000981:diagnostic imaging; D006801:Humans; D016131:Lymphocyte Subsets; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D011859:Radiography