title: Prevalence of antibodies to Ro-52 in a serologically defined population of patients with systemic sclerosis.
abstract: BACKGROUND
  Antibodies against Ro-52 have been described in patients with a broad spectrum of autoimmune disease, most commonly in association with anti-Ro-60 in systemic lupus erythematosus and Sjogrens syndrome. However, in inflammatory myositis anti-Ro-52 is frequently present without anti-Ro-60 and is closely linked to the presence of aminoacyl-tRNA synthetase (aats) antibodies. To date there have been no comprehensive reports on the frequency of anti-Ro-52 in systemic sclerosis (SSc), a disease characterised by hallmark autoantibodies that occur in non-overlapping subsets. Clinically, each antibody-defined group has a distinct pattern of organ involvement, some featuring myositis.
  
  
  OBJECTIVE
  To determine the frequency of anti-Ro-52 in serologically defined groups of SSc patients and to investigate a possible link with myositis-associated autoantibodies.
  
  
  METHODS
  Serum samples from 1010 patients with SSc and 55 and 32 patients with anti-aats and anti-Ku respectively were tested for the presence of anti-Ro-52 using a commercial ELISA.
  
  
  RESULTS
  The prevalence of anti-Ro-52 was 15-38% in nine of the eleven sub-groups. There were no significant differences in mean anti-Ro-52 levels in these groups with the exception of that defined by the presence of anti-U1-RNP. In the remaining groups defined by anti-Ro-60 and anti-aats, anti-Ro-52 was present in 92% and 100% respectively. In sera from non-SSc patients with anti-aats, anti-Ro-52 was detected in 64%.
  
  
  CONCLUSIONS
  Anti-Ro-52 is present throughout the SSc population. It is neither more prevalent in the myositis-associated antibody groups nor does it segregate with any other major SSc-specific autoantibodies. The co-existence of anti-Ro-52 with both anti-Ro-60 and anti-aats is confirmed.
authors.affiliation: Department of Clinical Immunology, Royal Free Hospital, London NW32QG, UK.
authors.forename: Jennifer C
authors.initials: JC
authors.lastname: Parker
authors.forename: Rufus W
authors.initials: RW
authors.lastname: Burlingame
authors.forename: Christopher C
authors.initials: CC
authors.lastname: Bunn