Barcelos, FilipeAbreu, IsabelPatto, José VazTrindade, HelderTeixeira, Ana2017-07-172017-07-172009-100303-464XPURE: 291953PURE UUID: 6b3f7ece-6604-4237-8453-de425299d0cbresearchoutputwizard: 13287PubMed: 20087267WOS: 000273749400005Scopus: 79952112001http://hdl.handle.net/10362/22009Objectives: The purpose of this study was to evaluate the prevalence and clinical significance of anti-cyclic citrullinated peptide antibodies (anti-CCP-Abs), IgM and IgA rheumatoid factors (RFs) in primary Sjogren's Syndrome (pSS). Materials and Methods:We compared clinical and serological. characteristics of 31 pSS and 31 Rheumatoid Arthritis (RA) patients. Both, anti-CCP-Abs and RFs (IgM, IgA) directed against Fc determinants of IgG from humans and rabbit were detected by enzyme-linked immunosorbent assay (ELISA). We included 31 blood donors as control group for the evaluation of RFs and anti-CCP-Abs. Nine (29%) pSS patients presented arthritis, and 10 (32,3%) RA patients also had secondary Sjogren's syndrome (sSS) Results: IgM and IgA RFs prevalence was similar in pSS and RA, whichever the antigene (Human or Rabbit IgG) used. However, RA patients with sSS showed a tendency to present more often RF positivity, longer disease duration and higher ESR and CRP when compared with pSS patients with arthritis. Anti-CCP-Abs were detected in 64,5% of RA patients and in only 6,9% of pSS patients (p<0,0005). Anti-CCP-Abs were more often positive in RA patients with sSS (RA/sSS) (8 patients, 80%) than in RA patients without sSS (18 patients, 58,1%), and were absent in pSS patients with arthritis. RF-positive pSS patients presented more often pulmonary involvement and higher inflammatory parameters, and less often neuropathy compared to RF-negative patients. In controls, anti-CCP-Abs were absent and REs were negligible. Conclusions: Anti-CCP-Abs were detected in only a few pSS patients, none of whom presented arthritis, which contrasts with the high frequency of these antibodies in RA/sSS. These results suggest that anti-CCP-Abs could be useful in the distinction between pSS and RA with sSS. Although not useful for the differential diagnosis between RA and pSS, RFs may have a prognostic role in pSS.573405engIGMRheumatoidArthritisCLINICAL-SIGNIFICANCEELISA ASSAYSAnti-CCP AntibodiesRheumatoid FactorsPREVALENCESjogren's SyndromeDISEASEARTHRITISAUTOANTIBODIESSjögren’s SyndromeAnti-CCP AntibodiesRheumatoid FactorsRheumatoid ArthritisSDG 3 - Good Health and Well-beingjournal article