title: Characteristics of Sjögren's syndrome in rheumatoid arthritis.
abstract: OBJECTIVE
  To compare features of SS in RA with primary SS and RA without SS.
  
  
  METHODS
  Patients hospitalized between January 2007 and December 2010 were retrospectively studied. Seventy-four cases of overlap RA and SS (RA/SS) among 509 cases of RA were identified. Cases of SS (n = 187) detected during the same period acted as controls.
  
  
  RESULTS
  Among those with RA/SS, there were 46 cases of RA-onset SS and 12 cases of SS-onset RA. Sixteen patients had simultaneous-onset RA and SS. Compared with RA without SS, RA/SS patients had more severe arthritis; a higher incidence of haematological abnormality, fever and rash; and a higher frequency of RF, ANAs and anti-SSA and anti-SSB antibodies (P < 0.05). Compared with primary SS, RA/SS patients were older, had more severe arthritis, anaemia and lung involvement; a lower incidence of fever, rash, leucopenia, thrombocytopenia and hyperthyroidism; and a higher frequency of RF, anti-keratin antibody, anti-perinuclear factor and anti-cyclic citrullinated antibodies (P < 0.05). Compared with RA and primary SS, RA/SS patients had higher disease activity scores of both RA and SS.
  
  
  CONCLUSIONS
  RA/SS patients have distinctive features, with more complications and systemic involvement. In addition, disease activity is higher in RA/SS.
authors: Department of Rheumatology and Immunology, Peking University People's Hospital, 11 Xizhimen South Street, Beijing 100044, China.
authors: Jing
authors: J
authors: He
authors: Yan
authors: Y
authors: Ding
authors: Min
authors: M
authors: Feng
authors: Jianping
authors: J
authors: Guo
authors: Xiaolin
authors: X
authors: Sun
authors: Jing
authors: J
authors: Zhao
authors: Di
authors: D
authors: Yu
authors: Zhanguo
authors: Z
authors: Li
mesh_terms: D000328:Adult; D001172:Arthritis, Rheumatoid / Q000150:complications* / Q000276:immunology; D001323:Autoantibodies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012217:Rheumatoid Factor / Q000097:blood; D012720:Severity of Illness Index; D012859:Sjogren's Syndrome / Q000150:complications / Q000175:diagnosis* / Q000276:immunology
chemical_list: D001323:Autoantibodies; D012217:Rheumatoid Factor
keywords: Sjögren’s syndrome; disease activity; rheumatoid arthritis