Background/Purpose:

CD19+CD24^hiCD38^hi B cells demonstrate a regulatory capacity and their frequency is altered in the peripheral blood of patients with various autoimmune diseases. The pathogenic implication of autoinflammatory and/or autoimmune mechanisms has been reported in spondyloarthritis (SpA), and an increased frequency of circulating B cells expressing a regulatory phenotype has been described in SpA (Cantaert T. et al, Arthrits Rheumatol 2012). Therefore our objective was to study the frequency of CD19+CD24^hi CD38^hi B cells (Breg) in patients with Ankylosing Spondylitis (AS) naïve for TNF blockers, and the effect of anti-TNFα drugs on this B cell subset in AS.

Methods:

Peripheral blood was drawn from AS patients naïve for TNFα blockers (AS/nb) (n=42), AS patients who were already receiving treatment with anti-TNFα drugs (AS/b) (n=59: 37 infliximab, 10 adalimumab, 10 golimumab, 2 certolizumab) and healthy controls (HC) matched for age and gender (n=101). In addition, six AS/nb patients who were started on anti-TNFα drugs (2 infliximab, 1 adalimumab, 2 golimumab, 1 certolizumab) donated blood at two time points: right before the first dose of anti-TNFα was administered and 6 months thereafter. For each of these 6 patients, the same healthy donor acted as a control on both occasions. After isolation by Ficoll-Hypaque, PBMCs were stained with antibodies to CD3, CD4, CD19, CD24, and CD38, and examined by cytometry.

Results:

When compared with HC, AS/nb patients demonstrated a significantly increased frequency of Breg cells, which did not correlate with ASDAS-CRP, serum calprotectin, CRP or ESR values. In contrast, in AS/b patients, the frequency of circulating Breg cells was not different from HC. The 6 AS/nb patients who started treatment with anti-TNFα drugs demonstrated a significant reduction of circulating Breg numbers, which were no longer elevated after six months of treatment. At the same time, a significant decrease of CRP, serum calprotectin and ASDAS-CRP was observed in all 6 patients; in 4 of them, the ∆ASDAS-CRP was > 2.0.

Conclusion:

An increased frequency of circulating CD19+CD24^hiCD38^hi B cells is observed in AS/nb patients, that does not correlate not related with disease activity parameters. Treatment with anti-TNFα drugs is able to downmodulate circulating Breg numbers in AS.

ACR Meeting Abstracts - https://acrabstracts.org/abstract/effect-of-anti-tnf%ce%b1-drugs-on-the-frequency-of-circulating-cd19cd24hicd38hi-breg-cells-in-ankylosing-spondylitis/