The aim of this 3 years prospective study is to determine the prevalence of anti-cyclic
citrullinated peptide (anti-CCP) antibodies in the sera of rheumatoid arthritis (RA)
patients and to assess their clinical significance in evaluation of disease activity and
prediction of radiological severity.
Serum samples from 90 patients with RA and 110 healthy control subjects were
tested. Anti-CCP titres were estimated by enzyme linked immunosorbent assay (ELISA).
Radiographs of the hands, wrists and forfeet were taken for all RA patients at baseline
and after 3 years. Radiographic damage and scoring were evaluated according to
Larsen-Dale index.
A positive anti-CCP test was highly specific for RA (diagnostic specificity 96.4%)
being found in 70% of the patients. Although IgM RF had a higher sensitivity, it was less
specific for RA (90.9%). The diagnostic specificity was greatest when tests for anti-CCP
and RF were found in combination (99.1%), There were highly significant differences as
regard anti-CCP titre in RA patients graded according to their functional capacity and
disease activity being higher in higher grades (P<0.001). There were highly significant
increase in radiological scoring of severity in anti-CCP +ve RA patients either at the
baseline or after 3 years of the study (P<0.001). Also, there were highly significant
increase in radiological scoring of severity in RA patients with positive both anti-CCP
antibodies and RF or either of them after 3 years and insignificant difference in patients
negative to both tests. |
