Anti-carbamylated protein antibodies in the pre-symptomatic phase of XXXX , their relationship with multiple anti-citrulline peptide antibodies and association with radiological damage.

@entity1 @entity14965 @entity7134 @entity309 @entity49401
INTRODUCTION: The presence of a new autoantibody system, anti-carbamylated protein (anti- @entity49401 ) antibodies, has been identified in @entity309 ( @entity309 ). The presence of anti- @entity49401 antibodies was evaluated in samples taken from individuals who subsequently developed @entity309 before and after onset of symptoms and related to previously analysed antibodies against citrullinated peptides ( @entity7134 specificities) and anti- @entity14965 . METHODS: A total of 252 individuals, with 423 samples from before onset of symptoms of @entity309 , and 197 population controls were identified as donors to the Medical Biobank of Northern Sweden; 192 of them were also sampled at the time of diagnosis. All samples were analysed for anti- @entity49401 IgG and anti- @entity14965 antibodies using ELISAs. Ten different antibody reactivities against citrullinated antigens ( @entity7134 specificities) were analysed using a custom-made microarray based on the ImmunoCAP ISAC system (Phadia). RESULTS: The concentration of anti- @entity49401 antibodies was significantly increased in the pre-symptomatic individuals compared with controls (P<0.001) and also increased significantly after disease onset (P<0.001). The sensitivity for anti- @entity49401 antibodies in the pre-symptomatic individuals was 13.9% (95% CI: 11 to 17.6) and 42.2% (95% CI: 35.4 to 49.3) following development of @entity309 . Anti- @entity49401 antibody positivity was found in 5.1% to 13.3% of individuals negative for anti- @entity14965 or @entity7134 specificities. Presence of anti- @entity49401 antibodies was significantly related to radiological destruction at baseline, at 24 months and also to radiological change (P<0.05, all). CONCLUSIONS: The results indicate that anti- @entity49401 antibodies are associated with disease development, even after adjusting for the presence of different @entity7134 fine specificities, and in anti- @entity14965 negative individuals and contribute to the identification of a subset of @entity1 with worse radiological progression of the disease independent of @entity7134 .
