PT  - JOURNAL ARTICLE
AU  - van de Stadt, Lotte A
AU  - van der Horst, Ann R
AU  - de Koning, Margret H M T
AU  - Bos, Wouter H
AU  - Wolbink, Gerrit Jan
AU  - van de Stadt, Rob J
AU  - Pruijn, Ger J M
AU  - Dijkmans, Ben A C
AU  - van Schaardenburg, Dirkjan
AU  - Hamann, Dörte
TI  - The extent of the anti-citrullinated protein antibody repertoire is associated with arthritis development in patients with seropositive arthralgia
AID  - 10.1136/ard.2010.132662
DP  - 2011 Jan 01
TA  - Annals of the Rheumatic Diseases
PG  - 128--133
VI  - 70
IP  - 1
4099  - http://ard.bmj.com/content/70/1/128.short
4100  - http://ard.bmj.com/content/70/1/128.full
SO  - Ann Rheum Dis2011 Jan 01; 70
AB  - Objectives To determine the fine specificity of anti-citrullinated protein antibodies (ACPA) in the early phase of arthritis development, the ACPA repertoire in arthralgia patients and the association with arthritis development were studied. Methods A total of 244 patients with arthralgia positive for anti-cyclic citrullinated peptide antibodies (aCCPs) and/or IgM rheumatoid factor (IgM-RF), without arthritis were included. Development of arthritis was defined as presence of one or more swollen joints at clinical examination during follow-up. Sera were tested at baseline for reactivity to five citrullinated peptides derived from fibrinogen (three), vimentin (one) and α-enolase (one) and five corresponding arginine peptides in an ELISA. Results In all, 69 patients (28%) developed arthritis in a median of 3 joints after a median follow-up of 11 (IQR 5–20) months. Reactivity to each peptide was significantly associated with arthritis development (p<0.001). The ACPA repertoire did not differ between patients who did or did not develop arthritis. Among aCCP-positive patients, patients recognising two or more additional citrullinated peptides developed arthritis more often (p=0.04). The number of recognised peptides was positively associated with the aCCP level (p<0.001). Crossreactivity between different peptides was minimal. Conclusions Arthritis development is not associated with recognition of a specific citrullinated peptide once joint complaints are present. The ACPA repertoire in some patients with arthralgia is expanded. High aCCP levels are associated with a qualitatively broad ACPA repertoire. Patients with an extended ACPA repertoire have a higher risk of developing arthritis.