RESEARCH - The role of the shared epitope in arthralgia with anti-CCP antibodies and its effect on anti-CCP levels

[Guest guest]

Ann Rheum Dis. Published Online First: 3 April 2008. doi:10.1136/ard.2008.089953

Copyright © 2008 BMJ Publishing Group Ltd & European League Against

Rheumatism

--------------------------------------------------------------------------------

Concise Report

The role of the shared epitope in arthralgia with anti-cyclic

citrullinated peptide antibodies (anti-CCP), and its effect on

anti-CCP levels

W H Bos 1, J Ursum 1, N de Vries 2, G M Bartelds 1, G J Wolbink 3, M T

Nurmohamed 4, I E van der Horst-Bruinsma 4, Rob J van de Stadt 1, J BA

Crusius 5, PP Tak 2, B AC Dijkmans 4 and D-J van Schaardenburg 6*

1 Jan van Breemen Instituut, Netherlands

2 Clinical Immunology & Rheumatology, Netherlands

3 Jan van Breemen instituut, Netherlands

4 VU university medical center, Netherlands

5 VU University medical center, Netherlands

6 Jan van Breemen Institute, Netherlands

Abstract

Objective: Patients presenting with both arthralgia and antibodies to

cyclic citrullinated peptide (anti-CCP) have an increased risk of

developing rheumatoid arthritis (RA). To further characterize this

patient group and shed more light on its relation with clinically

manifest early arthritis and established RA, an immunogenetic and

serological analysis was performed.

Methods: In a group of 111 patients with anti-CCP positive arthralgia,

anti-CCP levels and shared epitope (SE) status were determined. Data

were compared to 125 and 128 anti-CCP-positive patients with early

arthritis and established RA, respectively.

Results: In anti-CCP-positive arthralgia patients, the frequency of SE

allele positivity is significantly lower when compared to anti-CCP

positive early arthritis and established RA (58% vs. 80%, and 58% vs.

92%, respectively, both P < 0.001). Median anti-CCP levels were higher

in the group of SE positive arthralgia patients compared to the group

of SE-negative arthralgia patients (P = 0.02). Median anti-CCP levels

were similar in the groups of SE positive arthralgia and arthritis

patients.

Conclusions: The lower frequency of SE positivity in arthralgia

patients compared to RA patients indicates that, compared to

SE-positive patients, SE negative patients as a group go through a

longer arthralgia phase, or alternatively have a lower risk for

transition from anti-CCP positive arthralgia to RA. Furthermore, the

present results suggest that in this early stage the effect of the SE

on disease risk may be mediated through higher anti-CCP levels.

http://ard.bmj.com/cgi/content/abstract/ard.2008.089953v1?papetoc

--

Not an MD