title: Determination of specificity and sensitivity of anti-RA 33 in diagnosis of early rheumatoid arthritis.
abstract: BACKGROUND
  Rheumatoid arthritis is a chronic inflammatory disease with uncertain etiology characterized by symmetric polyarthritis in peripheral joints. Its diagnosis is based on clinical findings and serologic tests. They are rarely conclusive in early course of the disease. So, its early diagnosis could be difficult. The present study was designed to evaluate the role of Anti -RA33; an Auto-Antibody against RA33 in early diagnosis of the disease.
  
  
  METHODS
  forty three patients who had been visited in a Rheumatology Clinic were randomly selected. Their disease has been diagnosed by a Rheumatologist. 55 persons were chosen from healthy individuals who had attended in other clinic. Their age and sex were matched with the case group. Anti-RA33 and RF titers were measured in their blood sample using standard methods.
  
  
  RESULTS
  RF and Anti-RA33 titers had significant correlation in case group (p=0.015). Anti -RA33 test had 98% sensitivity, 20% specificity, 55% positive predictive value, and 90% negative predictive.
  
  
  CONCLUSIONS
  Anti -RA33 could have diagnostic and prognostic value in diagnosis and evaluation of patients with RA, and its differentiation from other small joint disorders, particularly when the other serologic tests are negative.
authors.forename: Mahin
authors.initials: M
authors.lastname: Lashkari
authors.affiliation: MD, rheumatologist, assistant professor, Metabolic Diseases Research Center, Qazvin University of Medical Science, Qazvin, Iran. anoori_92@yahoo.com.
authors.forename: Akram
authors.initials: A
authors.lastname: Noori
authors.forename: Fatemeh
authors.initials: F
authors.lastname: Hajiimanouchehri
authors.forename: Sonia
authors.initials: S
authors.lastname: Oveisi
authors.forename: Amir Mohammad
authors.initials: AM
authors.lastname: Kazemifar
mesh_terms: D000328:Adult; D000367:Age Factors; D001172:Arthritis, Rheumatoid / Q000175:diagnosis* / Q000276:immunology*; D001323:Autoantibodies; D015415:Biomarkers; D042241:Early Diagnosis; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012217:Rheumatoid Factor; D012680:Sensitivity and Specificity; D012737:Sex Factors
chemical_list: D001323:Autoantibodies; D015415:Biomarkers; D012217:Rheumatoid Factor