B-cell phenotype and IgD-CD27- memory B cells are affected by TNF-inhibitors and tocilizumab treatment in rheumatoid arthritis

Abstract

BackgroundThe use of TNF-inhibitors and/or the IL-6 receptor antagonist, tocilizumab, in rheumatoid arthritis (RA) have pleiotropic effects that also involve circulating B-cells. The main goal of this study was to assess the effect of TNF-inhibitors and tocilizumab on B-cell phenotype and gene expression in RA.MethodsBlood samples were collected from untreated early RA (ERA) patients, established RA patients under methotrexate treatment, established RA patients before and after treatment with TNF-inhibitors and tocilizumab, and healthy donors. B-cell subpopulations were characterized by flow cytometry and B-cell gene expression was analyzed by real-time PCR on isolated B-cells. Serum levels of BAFF, CXCL13 and sCD23 were determined by ELISA.ResultsThe frequency of total CD19+ B cells in circulation was similar between controls and all RA groups, irrespective of treatment, but double negative (DN) IgD-CD27- memory B cells were significantly increased in ERA and established RA when compared to controls. Treatment with TNF-inhibitors and tocilizumab restored the frequency of IgD-CD27- B-cells to normal levels, but did not affect other B cell subpopulations. TACI, CD95, CD5, HLA-DR and TLR9 expression on B-cells significantly increased after treatment with either TNF-inhibitors and/ or tocilizumab, but no significant changes were observed in BAFF-R, BCMA, CD69, CD86, CXCR5, CD23, CD38 and IgM expression on B-cells when comparing baseline with post-treatment follow-ups. Alterations in B-cell gene expression of BAFF-R, TACI, TLR9, FcγRIIB, BCL-2, BLIMP-1 and β2M were found in ERA and established RA patients, but no significant differences were observed after TNF-inhibitors and tocilizumab treatment when comparing baseline and follow-ups. Serum levels of CXCL13, sCD23 and BAFF were not significantly affected by treatment with TNF-inhibitors and tocilizumab.ConclusionsIn RA patients, the use of TNF-inhibitors and/ or tocilizumab treatment affects B-cell phenotype and IgD-CD27- memory B cells in circulation, but not B-cell gene expression levels.

Diminished CXCR5 expression in peripheral blood of patients with Sjögren's syndrome may relate to both genotype and salivary gland homing

“…2d). Also, in CD27 -IgDdouble-negative (DN) B cells, representing several small B cell populations [35], a decrease in circulating CXCR5 1 cells (P < 0Á01) and decreased expression levels of CXCR5 were noted in patients with SS (P < 0Á05) ( Fig. 2e).…”

Rheumatoid arthritis patients express a skewed repertoire of polyclonal, hypomutated B-cell receptors

“…Given the lack of NHS N-glycosylation motif mutations within the self-reactive IGHV4-34 IgG sequences, we hypothesise that these IgG hypoM B cells arise from an expanded pool of self-reactive innate like B cells (25). CD27ve IgD -ve B cells are increased in the blood of RA patients both at diagnosis and following synthetic DMARD therapy (36)(37)(38). CD27 is widely used as a marker of human memory B cells, but CD27 -ve IgG +ve B cells also contain a pool of short-lived memory cells (8,39,40).…”

B-lymphocyte subpopulations in patients with rheumatoid arthritis and the effect of an interleukin-6 receptor inhibitor on them.

“…Напротив, преобладание в В-клеточной субпопуляции двойных негативных В-клеток, которые чаще относят к В-клеткам памяти [16,17], может отражать активацию В-клеток при ревматоидном воспалении. Об этом свидетельствует ряд исследований [11,21,24], продемонстрировавших увеличение относительного числа этих клеток в популяции В-лимфоцитов периферической крови у больных с высокой активностью РА. Фенотипический анализ двойных негативных В-клеток (CD19+CD27-IgG-) у больных РА (n=44) показал, что их количество было выше, чем в группе здоровых доноров (n=45), и они были представлены гетерогенной смесью клеток, экспрессировавших IgA, IgM и, особенно, IgG [24].…”

“…Для лечения пациентов с высокой активностью РА с успехом применяются ингибиторы рецепторов ИЛ6, оказывающие быстрый положительный эффект в отношении широкого спектра клинических проявлений и лабораторных нарушений [6]. При хорошо изученной клинической эффективности и безопасности данные об их влиянии на В-клетки малочисленны и противоречивы [10,11].…”