Home

Current Issue

Archives

Guidelines for Authors

Classified Ads

Links

Search PubMed

Subscriptions

Subscriber Registration

Guidelines for Website Users

JRheum Update Service

Contact Info

ANNEMARIE L.M.A. JANSEN, IRENE E. van der HORST-BRUINSMA, DIRKJAN van SCHAARDENBURG, ROB J. van de STADT, MARGRET H.M.T. de KONING, and BEN A.C. DIJKMANS

ABSTRACT.

Objective. To study the diagnostic value of IgM rheumatoid factor (RF), IgA-RF, antibodies to cyclic citrullinated peptide (anti-CCP), and combinations of these antibodies, measured at baseline, to discriminate rheumatoid arthritis (RA) from undifferentiated polyarthritis (uPA) in patients with recent onset arthritis.

Methods. Patients with early arthritis with peripheral arthritis of 2 or more joints and symptom duration less than 3 years were clinically diagnosed as having RA or uPA by an experienced rheumatologist during the first year. Patients with bacterial, psoriatic, or crystal induced arthritis or spondyloarthropathy were excluded. Optimal cutoff values for serum IgM RF, IgA RF, and anti-CCP were deduced from receiver operating characteristics curves in order to predict the diagnosis of RA in early arthritis.

Results. A total of 379 patients (69% female, median age 57 yrs, range 17-86 yrs) were studied; 258 patients were clinically diagnosed as RA and 121 as uPA. Both IgM-RF > 40 IU/ml and anti-CCP > 50 AU/ml showed high specificity, but the sensitivity of these tests was low. In many RA patients the occurrence of IgM-RF and anti-CCP antibodies was independent. Thus the optimal criterion proved to be the combination of IgM-RF > 40 or anti-CCP > 50, which yielded sensitivity of 55.4% and specificity of 96.7%.

Conclusion. The criterion IgM-RF > 40 or anti-CCP > 50 is able to predict the diagnosis of RA in early arthritis patients with high specificity and acceptable sensitivity. Anti-CCP testing combined with IgM-RF testing has additional value over IgM-RF testing alone in patients with early undifferentiated oligo and polyarthritis. (J Rheumatol 2002;29:2074-6)

Key Indexing Terms:

ANTIBODIES
CYCLIC CITRULLINATED PEPTIDE
DIAGNOSIS
EARLY RHEUMATOID ARTHRITIS
UNDIFFERENTIATED POLYARTHRITIS

A.L.M.A. Jansen, PhD Student; R.J. van de Stadt, PhD; M.H.M.T. de Koning, Technician, Jan van Breemen Instituut; I.E. van der Horst-Bruinsma, MD, PhD, Department of Rheumatology, VU Medical Center; D. van Schaardenburg, MD, PhD; B.A.C. Dijkmans, MD, PhD, Jan van Breemen Instituut and Department of Rheumatology, VU Medical Center.

Address reprint requests to Dr. B.A.C. Dijkmans, Department of Rheumatology, University Hospital Vrije Universiteit, PO Box 7057, 1007 MB Amsterdam, The Netherlands. E-mail: secr.reumatologie@vumc.nl

Submitted August 16, 2001; revision accepted April 9, 2002.