Palindromic Rheumatism with Positive Anticitrullinated Peptide/Protein Antibodies Is Not Synonymous with Rheumatoid Arthritis. A Longterm Followup Study
The Journal of Rheumatology, 08/03/2012
Sanmarti R et al. – Anticitrullinated peptide/protein antibodies are frequently found in the sera of patients with palindromic rheumatism, and a significant proportion of these patients do not progress to rheumatoid arthritis in the long term.Methods
- The authors selected all patients in the clinic with PR who had at least 1 ACPA measurement.
- The authors included only patients with pure PR, defined as no evidence of associated rheumatic disease at the first serum ACPA measurement.
- Clinical characteristics, serum ACPA levels, duration of PR until serum ACPA measurement, and total followup time were recorded.
- The outcome variable was the definitive diagnosis of RA.
- The prognostic value of ACPA status in pure PR for a definite diagnosis of RA was analyzed by different statistical methods.
- Seventy-one patients (54 women/17 men) with a PR diagnosis were included.
- Serum ACPA were positive in 52.1%.
- After a mean followup of 7.6 ± 4.7 years since the first ACPA measurement, 24 patients (33.8%) progressed to chronic disease: 22% RA, 5.6% systemic lupus erythematosus, and 5.6% other diseases.
- The positive likelihood ratio of ACPA status for RA was 1.45, and the area under the receiver-operating characteristic curve of ACPA titers was 0.60 (95% CI 0.45-0.75).
- Progression to RA was more frequently seen in ACPA-positive than in ACPA-negative patients (29.7% vs 14.7%), but the difference was not significant (hazard ratio 2.46, 95% CI 0.77-7.86).
- Mean ACPA levels of patients with pure PR did not differ significantly from those of patients who progressed to RA.