title: Auto-reactions, autoimmunity and psoriatic arthritis.
abstract: Evidence from the literature suggests that autoimmune processes may drive features of psoriatic arthritis (PsA). Such hypothesis is supported by the evidence that class I major histocompatibility complex (MHC) genes are associated with susceptibility to develop PsA and auto-reactive cells, such as CD8 T cells, T helper (h) 17 and plasma cells, have been demonstrated in PsA. However, no autoantigens have ever been demonstrated in PsA. The presence of a new autoantibody system, anti-carbamylated protein (anti-CarP) antibodies, has been identified in rheumatoid arthritis (RA) patients. These autoantibodies have been associated with a worse disease progression independent of anti-citrulline antibodies (ACPA). In PsA, anti-CarP antibodies have not been evaluated yet. We aimed at analyzing, for the first time, the anti-CarP antibodies in sera of patients with active PsA who were negative for ACPA in order to explore both their presence and their relationship with disease activity. A total of 70 individuals, 30 patients with diagnosis of PsA (according to CASPAR criteria) and 40 healthy controls (HC) were enrolled. We found significantly increased levels of anti-CarP antibodies in PsA patients compared with HC (P<0.0001). Our findings indicate that anti-CarP antibodies are detectable with high specificity and sensibility in PsA patients suggesting an autoimmune background of PsA. Anti-CarP antibodies can be useful in improving the diagnosis of PsA and are correlated with disease activity.
authors.affiliation: Rheumatology, Allergology and Clinical Immunology, Department of "Medicina dei Sistemi", University of Rome Tor Vergata, Rome, Italy; Department of Experimental Medicine and Surgery, University of Rome Tor Vergata, Rome, Italy.
authors.forename: Maria Sole
authors.initials: MS
authors.lastname: Chimenti
authors.affiliation: Rheumatology, Allergology and Clinical Immunology, Department of "Medicina dei Sistemi", University of Rome Tor Vergata, Rome, Italy; Department of Experimental Medicine and Surgery, University of Rome Tor Vergata, Rome, Italy.
authors.forename: Paola
authors.initials: P
authors.lastname: Triggianese
authors.affiliation: Rheumatology, Allergology and Clinical Immunology, Department of "Medicina dei Sistemi", University of Rome Tor Vergata, Rome, Italy; Department of Experimental Medicine and Surgery, University of Rome Tor Vergata, Rome, Italy.
authors.forename: Marzia
authors.initials: M
authors.lastname: Nuccetelli
authors.affiliation: Rheumatology, Allergology and Clinical Immunology, Department of "Medicina dei Sistemi", University of Rome Tor Vergata, Rome, Italy; Department of Experimental Medicine and Surgery, University of Rome Tor Vergata, Rome, Italy.
authors.forename: Chiara
authors.initials: C
authors.lastname: Terracciano
authors.affiliation: Rheumatology, Allergology and Clinical Immunology, Department of "Medicina dei Sistemi", University of Rome Tor Vergata, Rome, Italy; Department of Experimental Medicine and Surgery, University of Rome Tor Vergata, Rome, Italy.
authors.forename: Anna
authors.initials: A
authors.lastname: Crisanti
authors.affiliation: Rheumatology, Allergology and Clinical Immunology, Department of "Medicina dei Sistemi", University of Rome Tor Vergata, Rome, Italy; Department of Experimental Medicine and Surgery, University of Rome Tor Vergata, Rome, Italy.
authors.forename: Maria Domenica
authors.initials: MD
authors.lastname: Guarino
authors.affiliation: Rheumatology, Allergology and Clinical Immunology, Department of "Medicina dei Sistemi", University of Rome Tor Vergata, Rome, Italy; Department of Experimental Medicine and Surgery, University of Rome Tor Vergata, Rome, Italy.
authors.forename: Sergio
authors.initials: S
authors.lastname: Bernardini
authors.affiliation: Rheumatology, Allergology and Clinical Immunology, Department of "Medicina dei Sistemi", University of Rome Tor Vergata, Rome, Italy; Department of Experimental Medicine and Surgery, University of Rome Tor Vergata, Rome, Italy. Electronic address: roberto.perricone@uniroma2.it.
authors.forename: Roberto
authors.initials: R
authors.lastname: Perricone
mesh_terms: D000818:Animals; D015535:Arthritis, Psoriatic / Q000276:immunology*; D001323:Autoantibodies / Q000276:immunology; D001324:Autoantigens / Q000276:immunology; D015551:Autoimmunity; D002221:Carbamyl Phosphate / Q000276:immunology; D002956:Citrulline / Q000276:immunology; D006801:Humans
chemical_list: D001323:Autoantibodies; D001324:Autoantigens; D002956:Citrulline; D002221:Carbamyl Phosphate
keywords: Anti-carbamylated protein antibodies; Auto-reactions; Autoimmunity; Psoriatic arthritis