Article Text

PDF
SAT0398 Diagnostic value of anti mutated citrullinated vimentin in comparison to anti-cyclic citrullinated peptide and anti-viral citrullinated peptide 2 antibodies in rheumatoid arthritis: A multicentric study by firma group
  1. E. Bartoloni1,
  2. A. Alunno1,
  3. O. Bistoni1,
  4. N. Bizzaro2,
  5. G. Morozzi3,
  6. A. Doria4,
  7. A. Mathieu5,
  8. M. Lotzniker6,
  9. F. Allegri7,
  10. V. Riccieri8,
  11. C. Alpini9,
  12. A. Gabrielli10,
  13. M. Tampoia11,
  14. R. Gerli1
  1. 1University of Perugia, Rheumatology Unit, Perugia
  2. 2Laboratorio Patologia Clinica, Ospedale S. Antonio, Tolmezzo
  3. 3Dip. Medicina Clinica Scienze Immunologiche, Sezione Reumatologia, Siena
  4. 4Division of Rheumatology, University of Padova, Padova
  5. 5Rheumatology Unit, University of Cagliari, Cagliari
  6. 6Laboratorio Analisi, Ospedale Civile, Legnano
  7. 7Allergologia ed Immunologia Clinica, Ospedale Civile, Brescia
  8. 8Dip. Medicina Interna e Specialità Mediche, Sapienza University, Rome
  9. 9Fondazione IRCCS, Policlinico S. Matteo, Pavia
  10. 10Clinica Medica, Università Politecnica delle Marche, Ancona
  11. 11Laboratorio di Patologia Clinica I, Policlinico Universitario, Bari, Italy

Abstract

Background In recent years the diagnostic approach to rheumatoid arthritis (RA) significantly changed. Among new serological assays, an ELISA test detecting antibodies directed against recombinant mutated citrullinated vimentin (anti-MCV), a protein widely expressed in the synovium, has been introduced to improve diagnosis. Anti-MCV appear slightly more or as sensitive as anti-cyclic citrullinated protein antibodies (anti-CCP), but less specific. However, its additional diagnostic value with respect to anti-CCP both in early and established RA is controversial.

Objectives Evaluate the diagnostic performance of anti-MCV assay in RA and to compare it to a standard anti-CCP test and the recently developed assay targeting viral citrullinated peptide 2 (VCP2) (1,2) in a large cohort of RA patients and healthy and disease controls.

Methods Sera (n=512) from long-standing RA patients (n=285) and healthy and disease controls (n=227) were randomly collected. Anti-CCP were measured by the routine method used in each Center. As 4 different assays were used, anti-CCP values were normalized and expressed as a ratio. Anti-VCP IgG were detected by the 2nd generation method (Astra Diagnostici, Milan, Italy) and anti-MCV by the available ELISA kit (Orgentec Diagnostika GmbH, Mainz, Germany). The receiver-operating characteristic (ROC) curve was calculated to determine the optimal cutoff values for each antibody assay.

Results At the calculated cutoff value of 55 U/mL, anti-MCV resulted to have a sensitivity of 59% and a specificity of 92%. In comparison, anti-CCP (calculated cutoff of 5 U/mL) and anti-VCP2 (calculated cutoff of 21 AU) displayed a sensitivity of 77% and 61% and a specificity of 96% and 95%, respectively. Of interest, a high percentage of healthy subjects as well as Epstain Barr and hepatitis C virus-infected patients resulted anti-MCV positive at the manufacturer recommended cutoff value of 20 U/mL.

Conclusions In our large cohort of RA patients, at the calculated cutoff of 55 U/mL, anti-MCV demonstrated lower sensitivity than anti-CCP and VCP2 test, thus not allowing to confirm previously published data. Moreover, the high rate of detection in infectious diseases limits its diagnostic value in undifferentiated arthritis. On the basis of our results, an international validated anti-MCV cutoff value to standardize the results is surely needed.

  1. Bizzaro N et al., J Clin Pathol 2011;64:1139

  2. Pratesi F et al., Clin Exp Immunol 2011;164:337

Disclosure of Interest None Declared

Statistics from Altmetric.com

Request permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.