Background CD19+CD24^highCD38^high B cells have been described to have a regulatory capacity and their frequency is altered in the peripheral blood of patients with various autoimmune diseases.

Objectives To determine the frequency of circulating CD19+CD24^highCD38^high B cells in patients with RA, and establish a correlation with clinical parameters.

Methods Peripheral blood was drawn from RA patients treated with non-biological DMARDs (n=48), RA patients treated with anti-TNFalpha drugs (n=15) and healthy controls (n=63) that were matched with patients for age and gender. After isolation by Ficoll-Hypaque gradient, PBMCs were stained with antibodies to CD3, CD4, CD19, CD24, and CD38, and examined by flow cytometry.

Results A decreased frequency of CD19+CD24^highCD38^high B cells was apparent in in ACPA+ but not ACPA- RA patients, and this was observed not only in patients treated with non-biological DMARDs but also in patients receiving anti-TNFalpha drugs. In addition, the frequency of CD19+CD24^highCD38^high B cells showed a significant negative correlation with ACPA titers (r = -0.43, p=0.023). In contrast, no correlation was found between the frequency of circulating CD19+CD24^highCD38^high B cells and either rheumatoid factor titres or disease activity as determined by the DAS28 score.

Conclusions A decreased frequency of CD19+CD24^highCD38^high B cells is observed in ACPA+ but not ACPA- RA patients treated with either nonbiological DMARDs or anti-TNFalpha drugs, that is related with ACPA titres but not with rheumatoid factor titres or disease activity.

Disclosure of Interest None declared