Multireader assessment as an alternative to reference assessment to improve the detection of radiographic progression in a large longitudinal cohort of rheumatoid arthritis (ESPOIR).

INTRODUCTION: Structural damage progression is a major outcome in rheumatoid arthritis (RA). Its evaluation and follow-up in trials should involve radiographic scoring by 1 or 2 readers (reference assessment), which is challenging in large longitudinal cohorts with multiple assessments. OBJECTIVES: To compare the reproducibility of multireader and reference assessment to improve the feasibility of detecting radiographic progression in a large cohort of patients with early arthritis (ESPOIR). METHODS: We used 3 sessions to train 12 rheumatologists in radiographic scoring by the van der Heijde-modified Sharp score (SHS). Multireader scoring was based on 10 trained-reader assessments, each reader scoring a random sample of 1/5 of all available radiographs (for double scoring for each X-ray set) for patients included in the ESPOIR cohort with complete radiographic data at M0 and M60. Reference scoring was performed by 2 experienced readers. Scoring was performed blindly to clinical data, with radiographs in chronological order. We compared multireader and reference assessments by intraclass correlation coefficients (ICCs) for SHS and significant radiographic progression (SRP). RESULTS: The intrareader and inter-reader reproducibility for trained assessors increased during the training sessions (ICC 0.79 to 0.94 and 0.76 to 0.92), respectively. For the 524 patients included, agreement between multireader and reference assessment of SHS progression between M0 and M60 and SRP assessment were almost perfect, ICC (0.88 (95% CI 0.82 to 0.93)) and (0.99 (95% CI 0.99 to 0.99)), respectively. CONCLUSIONS: Multireader assessment of radiographic structural damage progression is comparable to reference assessment and could be used to improve the feasibility of radiographic scoring in large longitudinal cohort with numerous X-ray evaluations.

Anticyclic citrullinated peptide antibodies in rheumatoid and nonrheumatoid rheumatic disorders: experience with 1162 patients.

OBJECTIVE: Anticyclic citrullinated peptide antibodies (anti-CCP) are considered specific markers of rheumatoid arthritis (RA) and have been included in the revised classification criteria for RA diagnosis. However, these antibodies have also been detected in patients with other types of chronic inflammatory rheumatism. Our objectives were to identify the prevalence of positive anti-CCP patients in non-RA diseases, to determine the diagnostic value of anti-CCP for the diagnosis of RA, to specify the clinical characteristics of non-RA patients positive for anti-CCP, and to determine the discriminatory value of the levels of anti-CCP in patients among the various diseases. METHODS: We carried out an observational and descriptive study. All the determinations of anti-CCP requested by the 2 rheumatology departments at Cochin Hospital over a period of 18 months were analyzed. Such determinations were requested for 1162 patients in total. Anti-CCP levels were determined with the Euro Diagnostica ELISA kit, with values ≥ 25 U for this test being considered positive. The diagnosis of rheumatic conditions was the responsibility of the treating physician. RESULTS: Anti-CCP antibodies were detected in 357 (30.7%) of the 1162 patients. The prevalence of anti-CCP was 292/417 (70.0%) in RA, 13/122 (10.6%) in patients with psoriatic arthritis, 13/62 (20.9%) in patients with unclassified rheumatism, 11/33 (33.3%) in patients with primary Sjögren syndrome, 5/30 (16.6%) in patients with systemic lupus erythematosus, 3/28 (10.7%) in patients with mixed connective tissue disorder, 3/36 (8.3%) in patients with systemic sclerosis, 7/44 (15.9%) in patients with juvenile arthritis, and 6/220 (2.7%) in patients with noninflammatory diseases. In the population of patients positive for anti-CCP, mean anti-CCP levels were 869.4 (± 978.4) U/ml, with no significant difference between RA [854.8 (± 959.8) U/ml] and any of the non-RA conditions [922.7 (± 1070.0) U/ml]. CONCLUSION: Anti-CCP are a hallmark of RA, but may be observed in other inflammatory, systemic, or mechanical diseases. In this large cohort of patients, the presence of second-generation anti-CCP (anti-CCP2) antibodies is useful in diagnosing RA (70% sensitivity, 91.3% specificity), but examining the levels of these antibodies does not appear to offer further discriminatory power among patients who are anti-CCP2-positive.