title: The Frequency of anti-CCP antibodies in patients with rheumatoid arthritis and psoriatic arthritis and their relationship with clinical features and parameters of angiogenesis: A comparative study.
abstract: OBJECTIVE
  Macrophage migration inhibitory factor (MIF) and vascular endothelial growth factor (VEGF), as crucial parameters of angiogenesis and inflammation, were evaluated to identify the role of cyclic citrullinated peptide antibodies (anti-CCP) during angiogenesis in rheumatoid arthritis (RA) and psoriatic arthritis (PsA).
  
  
  METHODS
  A total of 145 patients with RA, 44 patients with PsA, and 73 healthy subjects were included in this study. The clinical features, total blood counts, and acute phase parameters of RA and PsA patients were recorded. Anti-CCP antibody, VEGF, and MIF levels were determined with enzyme-linked immunosorbent assay (ELISA).
  
  
  RESULTS
  Anti-CCP positivity was significantly higher in the RA group (69%) than in both PsA (20.6%) and controls (8.2%) (p values<0.001). There was no difference between anti-CCP-positive and -negative RA patients regarding the extra-articular manifestations (p>0.05). VEGF and MIF levels were similar in anti-CCP-positive and -negative RA patients (all p values>0.05). The specificity of anti-CCP antibodies for RA was found to be 87.2%. No relationship was found between anti-CCP antibody positivity and clinical features, disease activity, functional disability as assessed by health assessment questionnaire scores, and extra-articular manifestations. There was no relationship between parameters of angiogenesis and anti-CCP antibody positivity. Both RF and anti-CCP antibodies were observed to be positive in most patients with RA.
  
  
  CONCLUSIONS
  Either RF or anti-CCP antibody was positive in a considerable proportion of our RA patients. Therefore, anti-CCP antibodies are important in the diagnosis of RF-negative patients who present with clinical findings of RA.
authors.affiliation: Department of Internal Medicine, Edirne State Hospital, Edirne, Turkey.
authors.forename: Yeliz Özkaya
authors.initials: YÖ
authors.lastname: Eker
authors.affiliation: Department of Rheumatology, Trakya University Faculty of Medicine, Edirne, Turkey.
authors.forename: Ömer Nuri
authors.initials: ÖN
authors.lastname: Pamuk
authors.affiliation: Department of Hematology, Trakya University Medical Faculty, Edirne, Turkey.
authors.forename: Gülsüm Emel
authors.initials: GE
authors.lastname: Pamuk
authors.affiliation: Department of Rheumatology, Trakya University Faculty of Medicine, Edirne, Turkey.
authors.forename: Salim
authors.initials: S
authors.lastname: Dönmez
authors.affiliation: Department of Rheumatology, Fatih Sultan Mehmet Education and Research Hospital, İstanbul, Turkey.
authors.forename: Necati
authors.initials: N
authors.lastname: Çakır
keywords: Rheumatoid arthritis; angiogenesis; anti-cyclic citrullinated peptide antibodies