title: Anti-RA 33 antinuclear autoantibody in rheumatoid arthritis and mixed connective tissue disease: comparison with antikeratin and antiperinuclear antibodies.
abstract: Besides rheumatoid factor (RF), antikeratin antibodies (AKA) and antiperinuclear factor (APN), anti-RA 33 antibody has been described as a highly specific antinuclear antibody for rheumatoid arthritis (RA). In this study RA 33 antibodies were detected using Western blotting with HeLa cell nuclear extract in a group of 94 RA patients and 259 controls. Anti-RA 33 was present in 35% of 94 RA patients, with a similar frequency in RF positive (32%) and RF-negative (45%) RA patients. RA-33 antibody was also present in 60% of a group of 30 patients with anti-U1 RNP positive mixed connective tissue disease. The specificity of anti-RA 33 for RA was 84.6%. Anti-RA 33 antibody was already present in sera from 23.5% of 18 patients with RA of less than one year's duration. Anti-RA 33 antibody was the only positive immunological marker in 3/20 cases of seronegative adult RA. No correlations were found between anti-RA 33 antibody and AKA or APF. Patients with erosive RA and patients whose ESR was > or = 50 mm after 1 hour were more likely to be anti-RA 33 positive (47.6% vs 24.4% and 42.8% vs 29.4%). These results suggest that anti-RA 33 antibody, in the absence of anti-U1-RNP antibodies, can be added to the list of the helpful serological markers for rheumatoid arthritis.
authors.affiliation: Clinique de Rhumatologie, Université Paris, Hôpital Bichat, France.
authors.forename: O
authors.initials: O
authors.lastname: Meyer
authors.forename: F
authors.initials: F
authors.lastname: Tauxe
authors.forename: D
authors.initials: D
authors.lastname: Fabregas
authors.forename: C
authors.initials: C
authors.lastname: Gabay
authors.forename: M
authors.initials: M
authors.lastname: Goycochea
authors.forename: T
authors.initials: T
authors.lastname: Haim
authors.forename: A
authors.initials: A
authors.lastname: Elias
authors.forename: M F
authors.initials: MF
authors.lastname: Kahn
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019268:Antibodies, Antineutrophil Cytoplasmic; D000974:Antibodies, Antinuclear / Q000097:blood*; D001172:Arthritis, Rheumatoid / Q000175:diagnosis / Q000276:immunology*; D001323:Autoantibodies / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007633:Keratins / Q000276:immunology; D008297:Male; D008875:Middle Aged; D008947:Mixed Connective Tissue Disease / Q000175:diagnosis / Q000276:immunology*; D012680:Sensitivity and Specificity
chemical_list: D019268:Antibodies, Antineutrophil Cytoplasmic; D000974:Antibodies, Antinuclear; D001323:Autoantibodies; D015415:Biomarkers; D007633:Keratins