Repeated anticitrullinated protein antibody and rheumatoid factor assessment is not necessary in early arthritis: results from the ESPOIR cohort.
OBJECTIVE
Presence and levels of anticyclic citrullinated peptide antibodies (anti-CCP) and rheumatoid factor (RF) contribute to the classification and prognosis of rheumatoid arthritis (RA). The objective was to determine the usefulness of repeating anti-CCP/RF measurements during the first 2 years of followup in patients with early arthritis.


METHODS
In patients with early undifferentiated arthritis, serial anti-CCP and RF were measured using automated second-generation assays every 6 months for 2 years. Frequencies of seroconversions (from negative to positive or the reverse) and changes in antibody levels during followup were determined.


RESULTS
In all, 775 patients, mean (SD) age 48.2 (12.5) years, mean symptom duration 3.4 (1.7) months, 76.6% female, were analyzed; 614 (79.2%) satisfied the American College of Rheumatology/European League Against Rheumatism 2010 classification criteria for RA at baseline. At baseline, respectively for anti-CCP and RF, 318 (41.0%) and 181 (23.4%) patients were positive, of whom 298 (93.7% of the positive) and 111 (61.3% of the positive) were highly positive (above 3 × upper limit of the norm). There were only 12 anti-CCP seroconversions toward the positive (i.e., 2.6% of the anti-CCP-negative), 21 seroconversions toward the negative (6.6% of the anti-CCP-positive), and 8 (1.0%) changes to a higher anti-CCP level category during the 2-year followup; respectively for RF, 27 (4.6%), 95 (52.5%), and 13 (1.7%).


CONCLUSIONS
In this cohort of patients with early arthritis, including in the subset of patients who did not fulfill the RA criteria, antibody status showed little increase over a 2-year period. Repeated measurements of anti-CCP/RF very infrequently offer significant additional information.
From the Universite Pierre et Marie Curie, Paris; APHP, Pitie-Salpetriere Hospital, Department of Rheumatology, Paris; Paris Descartes University, Faculty of Medicine, Paris; APHP, Rheumatology B Department, Cochin Hospital, Paris; Department of Rheumatology, Lapeyronie Hospital, UMR 5535, Montpellier I University, Montpellier; Paris 7 Denis Diderot University, Paris; APHP, Bichat Hospital, Paris, France.
Laure
L
Gossec
Simon
S
Paternotte
Bernard
B
Combe
Olivier
O
Meyer
Maxime
M
Dougados
D000328:Adult; D001172:Arthritis, Rheumatoid / Q000097:blood* / Q000276:immunology; D001323:Autoantibodies / Q000097:blood*; D015331:Cohort Studies; D018450:Disease Progression; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010456:Peptides, Cyclic / Q000276:immunology*; D011446:Prospective Studies; D012217:Rheumatoid Factor / Q000097:blood*
D001323:Autoantibodies; D010456:Peptides, Cyclic; C487763:cyclic citrullinated peptide; D012217:Rheumatoid Factor
ANTICYCLIC CITRULLINATED PEPTIDE ANTIBODIES; BIOMARKERS; LABORATORY DIAGNOSIS; RHEUMATOID ARTHRITIS; RHEUMATOID FACTOR