title: A proposal of criteria for the classification of systemic sclerosis.
abstract: BACKGROUND
  Sensitive and specific criteria for the classification of systemic sclerosis are required by clinicians and investigators to achieve higher quality clinical studies and approaches to therapy. A clinical study of systemic sclerosis patients in Europe and Canada led to a set of criteria that achieve high sensitivity and specificity.
  
  
  METHODS
  Both clinical and laboratory investigations of patients with systemic sclerosis, related conditions and diseases with clinical features that can be mistaken as part of the systemic sclerosis spectrum were undertaken. Laboratory investigations included the detection of autoantibodies to centromere proteins, Scl-70 (topoisomerase I), and fibrillarin (U3-RNP).
  
  
  RESULTS
  Based on the investigation of 269 systemic sclerosis patients and 720 patients presenting with related and confounding conditions, the following set of criteria for the classification of systemic sclerosis was proposed: 1) autoantibodies to: centromere proteins, Scl-70 (topo I), fibrillarin; 2) bibasilar pulmonary fibrosis; 3) contractures of the digital joints or prayer sign; 4) dermal thickening proximal to the wrists; 5) calcinosis cutis; 6) Raynaud's phenomenon; 7) esophageal distal hypomotility or reflux-esophagitis; 8) sclerodactyly or non-pitting digital edema; 9) teleangiectasias. The classification of definite SSc requires at least three of the above criteria.
  
  
  CONCLUSIONS
  Criteria for the classification of systemic sclerosis have been proposed. Preliminary testing has defined the sensitivity and specificity of these criteria as high as 99% and 100%, respectively. Testing and validation of the proposed criteria by other clinical centers is required.
authors.affiliation: Lviv Medical University, Department of Internal Medicine, Lviv, Ukraine.
authors.forename: Oleg
authors.initials: O
authors.lastname: Nadashkevich
authors.forename: Paul
authors.initials: P
authors.lastname: Davis
authors.forename: Marvin J
authors.initials: MJ
authors.lastname: Fritzler
mesh_terms: D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008297:Male; D012595:Scleroderma, Systemic / Q000145:classification* / Q000175:diagnosis / Q000378:metabolism