FRI0020 Anti-cep-1 antibodies and other autoantibodies in early arthritis
Authors: M. Ponikowska, J. Świerkot, B. Nowak, L. Korman, P. Wiland
Journal: Annals of the Rheumatic Diseases (2018)

<h3>Background</h3> As it is very important to identify patients with a high risk of <i>developing rheumatoid arthritis</i> (RA), new, diagnostic methods, evaluating the possibility of progression from undifferentiated arthritis (UA) to RA are needed. <h3>Objectives</h3> The aim of this work was the evaluation of the frequency of rheumatoid factor, anti-cyclic citrullinated peptide (anti-CCP) antibodies, mutated citrullinated vimentin antibodies (a-Sa), anti–CEP-1 antibodies, anti-filaggrin antibodies (AFA), heterogeneous nuclear ribonucleoprotein compies/anti-RA33-antibody (<i>HnRNP</i>/<i>RA33</i>), anti-<i>CarP antibodies</i> (a-Carp) in patients with early arthritis. <h3>Methods</h3> 74 patients with early arthritis and 20 healthy volunteers were enrolled to the study. 51 patients were diagnosed with RA, 23 with UA. Exclusion criteria were the application of disease-modifying antirheumatic drugs or glucocorticosteroids. In all patients the following laboratory tests were performed: inflammatory markers, rheumatoid factor (RF) and antibodies mentioned above, together with necessary diagnostic that enables diagnosis. <h3>Results</h3> In patients with early arthritis the sensitivity and specificity of the presence of RF was 69% and 95%, respectively, and of anti-CCP was 67% and 97%. In patients with early arthritis we observed significantly higher concentration of CEP-1 (65,8±111,6) than in the healthy group (2,0±0,0). In RF(+) RA patients we observed higher concentration of antibodies a-Sa and CEP-1 than in other groups. Antibodies a-Sa were positive in 69% of RF(+) RA patients, in 37% of RF(-) RA patients, in 26% of UA patients and in 10% of healthy people. In 8 aCCP (-) and RF(-) patients we observed the presence of a-Sa; 3 of them were diagnosed with RF(-) RA with and 5 with UA. Anti–CEP-1 antibodies were positive in 77% of RF(+) RA patients, in 56% of RF(-) RA patients, in 4,5% of UA patients, but their presence were not observed in the healthy people. In 8 aCPP (-) and RF (-) patients we observed positive anti–CEP-1 antibodies; 6 of them were diagnosed with RA, 2 of them with UA. Anti–CEP-1 antibodies were positive in 50% of RF(-) RA patients, in whom there was no aCCP nor RF, and only in 4,5% of UA patients. In case of marking a-Car-P, positive values were present in: the group of RF(+) RA in 40% of patients, in patients diagnosed with RF(-) RA in 6%, in case of UA in 22% of patients. In patients with RF(+) RA, positive anti-<i>CarP antibodies are present statistically significantly more often than in the group of RF (-) RA patients</i> (p<i>&lt;0,05).</i> In case of marking hnRNP/RA33 and AFA no statistically significant differences between RF(+) RA, RF(-) RA and UA in their occurrence were observed. In patients with arthritis no correlation between smoking and analysed autoantibodies was observed. In smokers higher CRP concentration and ESR values was observed. <h3>Conclusions</h3> Our results suggest that a-Sa and CEP-1 parameters allow to differentiate RF(+) RA, RF(-) RA and UA, but do not differentiate UA from RF(-) RA. Marking CEP-1 in patients with early arthritis may help in differentiation between RF(-) RA and UA. Marking CEP-1 and a-Sa may be useful in diagnosing early arthritis patients. The presence of Anti-<i>CarP antibodies in UA patients is probably considerable risk factor in RA development.</i> Smoking cessation may contribute to decrease RA activity. <h3>Disclosure of Interest</h3> None declared