title: Comparative study of 4 diagnosis criteria sets for mixed connective tissue disease in patients with anti-RNP antibodies. Autoimmunity Group of the Hospitals of Toulouse.
abstract: OBJECTIVE
  To evaluate the performances of 4 sets of criteria proposed to define mixed connective tissue disease (MCTD): the criteria of Sharp, Alarcón-Segovia, Kasukawa, and Kahn. As anti-U1-RNP antibodies appear indispensable to establish the diagnosis of MCTD, we wished to reevaluate these sets of criteria in patients who all had anti-U1-RNP antibodies.
  
  
  METHODS
  We analyzed clinical and biological data to find which diagnostic criteria were met by 45 patients with anti-U1-RNP antibodies. We tested criteria for rheumatoid arthritis, systemic lupus erythematosus, systemic sclerosis, polymyositis, Sjögren's syndrome, and 4 sets of criteria for MCTD.
  
  
  RESULTS
  The criteria that best identified patients with MCTD were those proposed by Alarcón-Segovia, with 62.5% sensitivity and 86.2% specificity, comparable to Kahn's criteria. The overlap with other connective tissue diseases was found to be 16%. These results could be improved by using the term "myalgia" instead of "myositis" in the definition. This increased sensitivity to 81.3%, with no decrease in specificity.
  
  
  CONCLUSIONS
  Alarcón-Segovia's and Kahn's criteria are the best classification criteria to define MCTD.
authors.affiliation: Rheumatology Department, Rangueil University Hospital, Toulouse, France.
authors.forename: J M
authors.initials: JM
authors.lastname: Amigues
authors.forename: A
authors.initials: A
authors.lastname: Cantagrel
authors.forename: M
authors.initials: M
authors.lastname: Abbal
authors.forename: B
authors.initials: B
authors.lastname: Mazieres
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000974:Antibodies, Antinuclear / Q000032:analysis*; D003240:Connective Tissue Diseases / Q000175:diagnosis; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008947:Mixed Connective Tissue Disease / Q000145:classification / Q000175:diagnosis* / Q000276:immunology*; D017412:Ribonucleoprotein, U1 Small Nuclear / Q000276:immunology*; D012680:Sensitivity and Specificity
chemical_list: D000974:Antibodies, Antinuclear; D017412:Ribonucleoprotein, U1 Small Nuclear