Background Rheumatoid artritis (RA) is a systemic autoimmune disease of unknown and multifactorial aetiology, whoseprevalence is around 1% of the adult population. Anti citrullinated peptide antibodies (ACPA) are the most specific serological markers of RA, with a specificity of 98%–99% in some studies. The presence of autoantibodies such as rheumatoid factor (RF) and ACPA is related to more severe structural damage and joint destruction during disease progression.
Objectives To assess whether the presence of ACPA is associated with higher levels of disease activity score (DAS 28) in a sample of patients with RA.
Methods We performed a descriptive study of a cohort of patients from Valme Hospital diagnosed with RA. Patients were identified from an electronic database. Demographic data, inmunological profile (presence of RF and/or ACPA),treatment (DMARDs or biological therapy) and disease activity measured by DAS 28 were collected transversely.
Results Two hundred and sixty RA patients were included, current average age of 58.5 years, 72% were women, 48% were receiving biological therapy. Regarding serological markers, 61% were ACPA positive, 65% were RF positive and 54.3% were ACPA and RF positive. Mean DAS28 was 2.6 for RF and ACPA negative patients, compared to 2.8 for patients that showed positivity for one or both autoantibodies, without statistically significant difference. With respect to the subgroup of patients receiving biological treatment (n=122), no significant difference of the mean value of DAS28 was seen (regarding to the presence/absence of ACPA): DAS28 2,53 for ACPA positive versus 2.52 for ACPA negative.
Conclusions The presence of ACPA in RA patients has been traditionally considered a predictor of radiographic progression and higher clinical activity. But recently, new studies suggest that, although ACPA positivity does maintain relationship with structural damage, there is no association with the severity of clinical activity measured by DAS28.1 In line with with these results, in our population of RA we found no relationship between the presence of ACPA and/or RF and disease activity, but it should be noted that the present is a cross-sectional study, so further prospective studies will be needed to elucidate this point.
Reference M Kaushik R. Anti-Cyclic Citrullinated Peptide Antibodies as a Predictor of Clinical and Radiological Disease Severity in Rheumatoid Arthritis. Curr Rheumatol Rev2015 Jan 13.