Difference of anti-cyclic citrullinated peptide antibody in patients with rheunmtoid arthritis in different age groups

Abstract

Objective To evaluate the clinical value of anti-cyclic citrullinated peptide (anti- CCP) anti-body in patients with rheumatoid arthritis(RA) in different agagroup.Methods Anti-CCP antibody was detected by ELISA in 220 cases of RA who were divided into three groups by onset age: juvenile group(n=24) ,adult group (n = 162) and older age group (n = 34).Results The ratio of anti-CCP in three groups were 14.3% (2/14), 81.7% (98/120) and 67.9% (19/28)(χ2 = 42.819, P <0.01).There was good coherence between the of anti-CCP and rheumatic factors (RF), with coherence coefficients of 71.4% (10/14 ), 82.2% (97/118) and 82.1% (23/28).Positive rank correlation was only found between anti-CCP and stages of X-rays(rs=0.243,P=0.002).Patients of juvenile group with anti-CCP were all present in poly-article subtype.There was a linear correlation be-tween anti-CCP and numbers of swollen joint, index of swollen joint in patients of juvenile group (r=0.563, P=0.045;r=0.574,P=0.040).The stage of both hand joints in older patients with anti-CCP positive was poorer than in those with anti-CCP negative[X-ray stage Ⅲ + Ⅳ was 52.2% (12/23), Ⅰ + Ⅱwas 0(0/9),χ2 =2.298,P =0.022].Conclusion The incidences of anti-CCP vary significantly among different age patients with RA.Anti-CCP in patients of juvenile group is related with poly-joint subtype, indicating the worsened swollen of joint.Anti-CCP in older age-onset patients with RA means the more severity of bone erosion. Key words: Rheumatoid arthritis; Anti-cyclic citrullinated peptide antibody; Age