Stefan Kleinert

In Vivo Effects of the Anti―Interleukin-6 Receptor Inhibitor Tocilizumab on the B Cell Compartment

OBJECTIVE Interleukin-6 (IL-6) receptor inhibition by tocilizumab was recently licensed for the treatment of rheumatoid arthritis (RA). IL-6 induces in vitro differentiation of B cells into antibody-forming cells; however, the in vivo effects of IL-6 inhibition on the B cell compartment are currently not known. The purpose of this study was to examine this feature. METHODS Sixteen patients with active RA were treated in an open-label study with tocilizumab (8 mg/kg every 4 weeks). Immunophenotyping was performed at baseline, week 12, and week 24. RESULTS Memory B cell subsets declined significantly during tocilizumab therapy. Preswitch memory B cells decreased from a median of 19.6% to 12.3% at week 24 and postswitch memory B cells declined from a median of 18.6% to 15.0% at week 24 (P = 0.04). In parallel, CD19+IgA+ and CD19+IgG+ B cells decreased significantly. The proportion of IgA-expressing B cells fell from a median of 9.2% at baseline to 4.3% at week 12 and to 3.6% at week 24 (P = 0.01). IgG+ B cells declined from a median of 6.7% at baseline to 4.9% at week 12 (P = 0.007) and 2.8% at week 24 (P = 0.01). In parallel, serum levels of IgA and IgG were significantly diminished at week 24 (P < 0.05). There was a good correlation between relative and absolute numbers of IgA+ B cells with serum IgA at week 24. CONCLUSION Tocilizumab induced a significant reduction in the frequency of peripheral preswitch and postswitch memory B cells. In addition, the number of IgG+ and IgA+ B cells declined and correlated well with reduced serum immunoglobulin levels. The data indicate that IL-6 blockade affects the B cell hyperreactivity in RA patients.

Relapse rates in patients with rheumatoid arthritis in stable remission tapering or stopping antirheumatic therapy: interim results from the prospective randomised controlled RETRO study

Objective To prospectively analyse the risk for disease relapses in patients with rheumatoid arthritis (RA) in sustained remission, either continuing, tapering or stopping disease-modifying antirheumatic drugs (DMARDs) in a prospective randomised controlled trial. Methods Reduction of Therapy in patients with Rheumatoid arthritis in Ongoing remission is a multicentre, randomised controlled, parallel-group phase 3 trial evaluating the effects of tapering and stopping all conventional and/or biological DMARDs in patients with RA in stable remission. Patients (disease activity score 28 (DAS28)<2.6 for least 6 months) were randomised into three arms, either continuing DMARDs (arm 1), tapering DMARDs by 50% (arm 2) or stopping DMARDs after 6 months tapering (arm 3). The primary endpoint was sustained remission during 12 months. Results In this interim analysis, the first 101 patients who completed the study were analysed. At baseline, all patients fulfilled DAS28 remission and 70% also American College of Rheumatology- European League Against Rheumatism Boolean remission. 82.2% of the patients received methotrexate, 40.6% biological DMARDs and 9.9% other DMARDs. Overall, 67 patients (66.3%) remained in remission for 12 months, whereas 34 patients (33.7%) relapsed. The incidence of relapses was related to study arms (p=0.007; arm 1: 15.8%; arm 2: 38.9%; arm 3: 51.9%). Multivariate logistic regression identified anticitrullinated protein antibodies (ACPA) positivity (p=0.038) and treatment reduction (in comparison to continuation) as predictors for relapse (arm 2: p=0.012; arm 3: p=0.003). Conclusions This randomised controlled study testing three different treatment strategies in patients with RA in sustained remission demonstrated that more than half of the patients maintain in remission after tapering or stopping conventional and biological DMARD treatment. Relapses occurred particularly in the first 6 months after treatment reduction and were associated with the presence of ACPA. Trial registration number 2009-015740-42.

Impact of IL-6 receptor inhibition on human memory B cells in vivo: impaired somatic hypermutation in preswitch memory B cells and modulation of mutational targeting in memory B cells

Objective Interleukin 6 (IL-6) receptor (IL-6R) inhibition by tocilizumab is a novel anti-inflammatory therapy for rheumatoid arthritis (RA) patients. As IL-6 is a late differentiation factor of B cells the authors asked if IL-6R inhibition impacts on the mutational differentiation of human memory B-cell antigen receptors in vivo. Methods 1733 immunoglobulin receptors (IgR) of single cell sorted preswitch and postswitch memory B cells were prospectively analysed from 11 RA patients under IL-6R inhibition (7 patients) or tumour necrosis factor (TNF) inhibition (4 patients). Results The results show a reduced mutational frequency in IgR of preswitch memory B cells (p=0.0001) during week 12, week 24 and 1 year of tocilizumab therapy. Mutational hotspot RGYW/WRCY motifs indicated significantly decreased targeting (p<0.05) in preswitch and postswitch memory B cells. Anti-TNFα therapy had no effect on mutational frequency and mutational hotspot targeting motifs in memory B-cell subsets. Conclusions These data suggest that preswitch and postswitch memory B cells are susceptible to IL-6R inhibition in vivo. Acquisition of mutations was substantially altered in preswitch memory B cells, while targeting of mutational hotspots affected preswitch and postswitch memory B cells. The results indicate that preswitch and postswitch memory B cells have a differential dependence on the IL-6/IL-6R system for differentiation, which can be influenced by tocilizumab in vivo.

Prediction of disease relapses by multibiomarker disease activity and autoantibody status in patients with rheumatoid arthritis on tapering DMARD treatment

Objective To analyse the role of multibiomarker disease activity (MBDA) score in predicting disease relapses in patients with rheumatoid arthritis (RA) in sustained remission who tapered disease modifying antirheumatic drug (DMARD) therapy in RETRO, a prospective randomised controlled trial. Methods MBDA scores (scale 1–100) were determined based on 12 inflammation markers in baseline serum samples from 94 patients of the RETRO study. MBDA scores were compared between patients relapsing or remaining in remission when tapering DMARDs. Demographic and disease-specific parameters were included in multivariate logistic regression analysis for defining predictors of relapse. Results Moderate-to-high MBDA scores were found in 33% of patients with RA overall. Twice as many patients who relapsed (58%) had moderate/high MBDA compared with patients who remained in remission (21%). Baseline MBDA scores were significantly higher in patients with RA who were relapsing than those remaining in stable remission (N=94; p=0.0001) and those tapering/stopping (N=59; p=0.0001). Multivariate regression analysis identified MBDA scores as independent predictor for relapses in addition to anticitrullinated protein antibody (ACPA) status. Relapse rates were low (13%) in patients who were MBDA−/ACPA−, moderate in patients who were MBDA+/ACPA− (33.3%) and MBDA−ACPA+ (31.8%) and high in patients who were MBDA+/ACPA+ (76.4%). Conclusions MBDA improved the prediction of relapses in patients with RA in stable remission undergoing DMARD tapering. If combined with ACPA testing, MBDA allowed prediction of relapse in more than 80% of the patients. Trial registration number EudraCT 2009-015740-42.

RF positivity has substantial influence on the peripheral memory B-cell compartment and its modulation by TNF inhibition

Objectives: The role of B cells in rheumatoid arthritis (RA) has been well established with the advent of B-cell targeted therapies. Alterations of peripheral B-cell subsets in RA and heterogeneous modulations of the B-cell compartment under tumour necrosis factor (TNF) inhibition have been described. In this study we examined the influence of rheumatoid factor (RF) positivity on the peripheral B-cell compartment and its modulation under TNF blockade. Methods: Consecutive patients with RA and inadequate response to methotrexate (MTX) were stratified according to RF status and a subset of them was included in a prospective study of weekly etanercept treatment. Results: At baseline, RF-negative patients had a significant higher percentage of overall CD27+ B cells compared to healthy controls (HC) and RF-positive patients. In detail, RF-negative patients had 46.6% (range 15.7–86.8%) CD27+ B cells compared to 31.3% (12.9–56.9%, p = 0.026) in HC and 29.8% (19–73.3%, p = 0.04) in RF-positive patients. Within the CD27+ compartment, CD27+/immunoglobulin (Ig)D+ memory B cells were significantly increased to 26.4% (range 5.9–54.7%) in RF-negative patients compared to 14.9% (4.1–27.3%, p = 0.006) in HC and 10.5% (3.4–41.1%, p = 0.003) in RF-positive patients. During anti-TNF therapy, memory B cells increased significantly in relative and absolute numbers only in RF-negative patients. Conclusions: In RF-negative patients, we observed an enhanced frequency of peripheral memory B cells and an accumulation of pre-switch memory B cells. During anti-TNF therapy, memory B cells increased significantly only in RF-negative patients, suggesting that the peripheral memory B-cell compartment is more amenable to TNF inhibition in these patients.

Psoriatic arthritis: therapeutic principles

From the dermatologic point of view, psoriatic arthritis (PsA) was seen for a long time as a rare complication of psoriasis. Recent studies, however, reveal a high prevalence of PsA among patients with psoriasis, and the impact of PsA due to chronic inflammation of peripheral joints, axial joints, and periarticular structures leading to radiologic progression, functional impairment, and reduction in quality of life is well recognized. Substantial improvement in understanding immunopathology of PsA has led to a variety of new therapeutic options. This article reviews the current therapeutic principles for PsA.

Development and validation of a new disease activity score in 28 joints-based treatment response criterion for rheumatoid arthritis.

To define a valid criterion for treatment response as assessed by the Disease Activity Score in 28 joints (DAS28) that exceeds random disease activity variations in patients with rheumatoid arthritis (RA).

Antimodified protein antibody response pattern influences the risk for disease relapse in patients with rheumatoid arthritis tapering disease modifying antirheumatic drugs

Objective To perform a detailed analysis of the autoantibody response against post-translationally modified proteins in patients with rheumatoid arthritis (RA) in sustained remission and to explore whether its composition influences the risk for disease relapse when tapering disease modifying antirheumatic drug (DMARD) therapy. Methods Immune responses against 10 citrullinated, homocitrullinated/carbamylated and acetylated peptides, as well as unmodified vimentin (control) and cyclic citrullinated peptide 2 (CCP2) were tested in baseline serum samples from 94 patients of the RETRO study. Patients were classified according to the number of autoantibody reactivities (0–1/10, 2–5/10 and >5/10) or specificity groups (citrullination, carbamylation and acetylation; 0–3) and tested for their risk to develop relapses after DMARD tapering. Demographic and disease-specific parameters were included in multivariate logistic regression analysis for defining the role of autoantibodies in predicting relapse. Results Patients varied in their antimodified protein antibody response with the extremes from recognition of no (0/10) to all antigens (10/10). Antibodies against citrullinated vimentin (51%), acetylated ornithine (46%) and acetylated lysine (37%) were the most frequently observed subspecificities. Relapse risk significantly (p=0.011) increased from 18% (0–1/10 reactivities) to 34% (2–5/10) and 55% (>5/10). With respect to specificity groups (0–3), relapse risk significantly (p=0.021) increased from 18% (no reactivity) to 28%, 36% and finally to 52% with one, two or three antibody specificity groups, respectively. Conclusions The data suggest that the pattern of antimodified protein antibody response determines the risk of disease relapse in patients with RA tapering DMARD therapy. Trial registration number 2009-015740-42; Results.

Validation of Standardized Questionnaires Evaluating Symptoms of Depression in Rheumatoid Arthritis Patients: Approaches to Screening for a Frequent Yet Underrated Challenge

To validate standard self‐report questionnaires for depression screening in patients with rheumatoid arthritis (RA) and compare these measures to one another and to the Montgomery‐Åsberg Depression Rating Scale (MADRS), a standardized structured interview.

Rituximab Therapy Leads to Reduced Imprints of Receptor Revision in Immunoglobulin κ and λ Light Chains

Objective. Transient B cell depletion by rituximab (RTX) has become a specific treatment of rheumatoid arthritis (RA). Although phenotypic repopulation kinetics of B cell subsets are well documented, precise molecular analyses of the reconstituting immunoglobulin (Ig) genes encoding the B cell receptor in RA are sparse. Methods. A total of 708 individual CD19+CD27+ (memory) and CD19+CD27– (naive) B cells from 2 patients with RA were analyzed at baseline and 7 months after RTX at B cell repopulation. Ig light chain variable kappa (Vκ) and lambda (Vλ) light chain gene rearrangements were amplified, sequenced, and analyzed with a focus on receptor revision. Results. The naive as well as the memory repertoire repopulated polyclonally with diverse use of variable light chain gene families and minigenes. During the reconstitution phase, B cells used significantly fewer Jκ distal Vκ genes (p = 0.0006), with a higher frequency of somatic hypermutation of rearrangements employing Jκ5 compared to baseline in memory B cells. The use of Vλ rearrangements in regenerating B cells was also biased toward use of Vλ genes of the proximal cassette. In general, reemerging CD27+ Ig light chain genes were substantially more highly mutated than before RTX therapy (p < 0.0001, baseline vs during reconstitution). Conclusion. Our data indicate that RTX therapy leads to generation of distinct Vκ/Jκ and Vλ/Jλ gene repertoires consistent with replenishment of antigen-experienced B cells by germinal centers. At baseline, the imprints of receptor revision appeared to be more striking, which indicates that receptor revision is active in patients with RA and can be reduced by RTX.