Rheumatoid arthritis (RA) is one of the most common autoimmune diseases, affecting approximately 1-2% of the world population. One of the characteristic features of RA is the presence of autoantibodies. Especially the highly specific anti-citrullinated peptide antibodies (ACPAs), which have been found in up to 70% of RA patients' sera, have received much attention. Several citrullinated protein...

OBJECTIVES To assess the possible presence in patients with rheumatoid arthritis (RA) of autoantibodies recognising citrullinated peptides derived from type I and II collagens. METHODS Firstly, the binding of four pairs of synthetic peptides (arginine-containing and artificially citrullinated forms) related to different regions of human type II collagen were tested with sera from 120 patients...

Citrullinated peptides are major targets of disease-specific autoantibodies in rheumatoid arthritis. Currently, citrullinated peptides are used as biomarkers for diagnosing rheumatoid arthritis by measuring anti-citrullinated protein Ab (ACPA) titers in patients' sera. The accumulation of citrullinated proteins at synovial inflammation sites suggests that they are possible targets for tolerance...

Objective. To investigate whether citrullinated proteins within the atherosclerotic plaque can be targeted by anti–citrullinated protein antibodies (ACPAs), forming stimulatory immune complexes that propagate the progression of atherosclerosis. Methods. Protein lysates prepared from atherosclerotic segments of human aorta were assessed for the presence of citrulline-modified proteins, and speci...

BACKGROUND Autoreactive B cells are crucial players in the pathogenesis of rheumatoid arthritis (RA). Autoantibodies specific for citrullinated proteins (ACPA), present in the serum of approximately 60-70 % of patients, have a pathogenic role in the disease. B cell depleting therapies may result in a transient immunosuppression, increasing the risk of infections. Our aim was to develop a new th...

Peptidylarginine deiminases (PADs) convert arginine within a peptide (peptidylarginine) into peptidylcitrulline. Citrullination by human PADs is important in normal physiology and inflammation. Porphyromonas gingivalis, a major pathogen in periodontitis, is the only prokaryote described to possess PAD. P. gingivalis infection may generate citrullinated peptides, which trigger anti-citrullinated...

The prevalence rates of anti-citrullinated protein/peptide antibodies (ACPAs) were investigated in a cohort of juvenile idiopathic arthritis (JIA) patients, and their diagnostic performances were compared. ACPAs, including anti-cyclic citrullinated peptide IgG (anti-CCP), anti-CCP IgG/IgA (anti-CCP3.1), citrullinated recombinant rat filaggrin antibodies (CPA), anti-mutated citrullinated vimenti...

It has been hypothesized that HLA class II alleles associated with rheumatoid arthritis (RA) preferentially present self-antigens altered by post-translational modification, such as citrullination. To understand the role of citrullination we tested four RA-associated citrullinated epitopes and their corresponding wild-type version for binding to 28 common HLA class II. Binding patterns were var...

OBJECTIVE Previous studies have suggested a relationship between anticyclic citrullinated protein (CCP) levels and development of cardiovascular disease in rheumatoid arthritis (RA). However, a limited number of studies have demonstrated an involvement of anti-CCPs in those processes. This study was aimed to define the specific role of these auto-antibodies in the pro-oxidative, inflammatory, a...