Assessment of serum levels of anti-cyclic citrullinated peptide antibodies in patients with psoriatic arthritis: A cross-sectional study in a Brazilian cohort

Presence of the anti-cyclic citrullinated peptide (CCP) antibody is considered a hallmark of rheumatoid arthritis, and may be found in patients with other rheumatic diseases, including psoriatic arthritis (PsA). The aim of the present study was to determine whether the anti-CCP antibody was present in patients with psoriasis with and without arthritis. and to determine whether its presence was associated with clinical, serological and treatment data in patients with PsA. The present study was a cross-sectional study, which included 91 patients with psoriasis (41 with arthritis and 48 without arthritis) as well as an age and sex matched control group consisting of 100 healthy individuals. Presence of the anti-CCP antibody was determined using commercially available ELISA kits. Data on clinical, serological and treatment characteristics was obtained from reviewing each patient's medical history. The quality of life and articular inflammatory activity were assessed using the Short Form Health Survey-12 questionnaire. Skin disease was evaluated using the Psoriasis Area Severity Index and body surface area. In the control group, 1% of individuals were positive for the anti-CCP antibody, whereas 17.5% of the psoriasis patients were positive (P<0.001). In the patients with PsA, 20.9% were positive for the antibody, and in patients with psoriasis without joint disease, 14.5% were positive (P=0.58). Patients with polyarticular forms of PsA were more likely to be anti-CCP positive compared with patients with skin disease without arthritis (P=0.009). In the group of patients with PsA, those who were anti-CCP positive were more likely to suffer from polyarticular forms of arthritis, but no differences were found in the quality of life, joint disease activity, degree of skin involvement and treatment requirements (all P>0.05). In conclusion, 17.5% of patients with psoriasis and 20.9% of patients with PsA were positive for anti-CCP antibodies. Polyarticular arthritis was more common in the anti-CCP positive patients compared with the anti-CCP negative patients.