Baseline numbers of circulating CD28-negative T cells may predict clinical response to abatacept in patients with rheumatoid arthritis

The effect of abatacept on T-cell activation is not long-lived in vivo

Abatacept, a co-stimulatory blocker comprising the extracellular portion of human CTLA-4 linked to the Fc region of IgG1, is approved for the treatment of rheumatoid arthritis. By impairing the interaction between CD28 on T cells and CD80/CD86 on APCs, its mechanisms of action include the suppression of follicular T helper cells (preventing the breach of self-tolerance in B cells), inhibition of cell cycle progression holding T cells in a state described as 'induced naïve' and reduction in DC conditioning. However, less is known about how long these inhibitory effects might last, which is a critical question for therapeutic use in patients. Herein, employing a murine model of OVA-induced DTH, we demonstrate that the effect of abatacept is short-lived in vivo and that the inhibitory effects diminish markedly when treatment is ceased.

Monocyte-derived transcriptomes explain the ineffectiveness of abatacept in rheumatoid arthritis

BACKGROUND

The biological mechanisms underlying the differential response to abatacept in patients with rheumatoid arthritis (RA) are unknown. Here, we aimed to identify cellular, transcriptomic, and proteomic features that predict resistance to abatacept in patients with RA.

METHODS

Blood samples were collected from 22 RA patients treated with abatacept at baseline and after 3 months of treatment. Response to treatment was defined by the European League Against Rheumatism (EULAR) response criteria at 3 months, and seven patients were classified as responders and the others as non-responders. We quantified gene expression levels by RNA sequencing, 67 plasma protein levels, and the expression of surface molecules (CD3, 19, and 56) by flow cytometry. In addition, three gene expression data sets, comprising a total of 27 responders and 50 non-responders, were used to replicate the results.

RESULTS

Among the clinical characteristics, the number of monocytes was significantly higher in the non-responders before treatment. Cell type enrichment analysis showed that differentially expressed genes (DEGs) between responders and non-responders were enriched in monocytes. Gene set enrichment analysis, together with single-cell analysis and deconvolution analysis, identified that Toll-like receptor 5 (TLR5) and interleukin-17 receptor A (IL17RA) pathway in monocytes was upregulated in non-responders. Hepatocyte growth factor (HGF) correlated with this signature showed higher concentrations in non-responders before treatment. The DEGs in the replication set were also enriched for the genes expressed in monocytes, not for the TLR5 and IL17RA pathway but for the oxidative phosphorylation (OXPHOS) pathway.

CONCLUSIONS

Monocyte-derived transcriptomic features before treatment underlie the differences in abatacept efficacy in patients with RA. The pathway activated in monocytes was the TLR5 and IL17RA-HGF signature in the current study, while it was the OXPHOS pathway in the replication set. Elevated levels of HGF before treatment may serve as a potential biomarker for predicting poor responses to abatacept. These findings provide insights into the biological mechanisms of abatacept resistance, contributing valuable evidence for stratifying patients with RA.

Acazicolcept (ALPN-101), a dual ICOS/CD28 antagonist, demonstrates efficacy in systemic sclerosis preclinical mouse models

Background

Uncontrolled immune response with T cell activation has a key role in the pathogenesis of systemic sclerosis (SSc), a disorder that is characterized by generalized fibrosis affecting particularly the lungs and skin. Costimulatory molecules are key players during immune activation, and recent evidence supports a role of CD28 and ICOS in the development of fibrosis. We herein investigated the efficacy of acazicolcept (ALPN-101), a dual ICOS/CD28 antagonist, in two complementary SSc-related mouse models recapitulating skin fibrosis, interstitial lung disease, and pulmonary hypertension.

Methods

Expression of circulating soluble ICOS and skin-expressed ICOS was investigated in SSc patients. Thereafter, acazicolcept was evaluated in the hypochlorous acid (HOCL)-induced dermal fibrosis mouse model and in the Fra-2 transgenic (Tg) mouse model. In each model, mice received 400 μg of acazicolcept or a molar-matched dose of an Fc control protein twice a week for 6 weeks. After 6 weeks, skin and lung were evaluated.

Results

ICOS was significantly increased in the sera from SSc patients and in SSc skin biopsies as compared to samples from healthy controls. Similar body weight changes were observed between Fc control and acazicolcept groups in both HOCL and Fra-2 Tg mice suggesting a good tolerance of acazicolcept treatment. In mice challenged with HOCL, acazicolcept induced a significant decrease in dermal thickness, collagen content, myofibroblast number, and inflammatory infiltrates characterized by B cells, T cells, neutrophils, and macrophages. In the Fra-2 Tg mouse model, acazicolcept treatment reduced lung collagen content, fibrillar collagen, histological fibrosis score, and right ventricular systolic pressure (RVSP). A reduction in frequency of CD4+ and T effector memory cells and an increase in the percentage of CD4+ T naïve cells in spleen and lung of acazicolcept-treated Fra-2 Tg mice was observed as compared to Fc control-treated Fra-2 Tg mice. Moreover, acazicolcept reduced CD69 and PD-1 expression on CD4+ T cells from the spleen and the lung. Target engagement by acazicolcept was demonstrated by blockade of CD28 and ICOS detection by flow cytometry in treated mice.

Conclusions

Our results confirm the importance of costimulatory molecules in inflammatory-driven fibrosis. Our data highlight a key role of ICOS and CD28 in SSc. Using complementary models, we demonstrated that dual ICOS/CD28 blockade by acazicolcept decreased dermal and pulmonary fibrosis and alleviated pulmonary hypertension. These results pave the way for subsequent research on ICOS/CD28-targeted therapies.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13075-021-02709-2.

Toward Overcoming Treatment Failure in Rheumatoid Arthritis

Rheumatoid arthritis (RA) is an autoimmune disorder characterized by inflammation and bone erosion. The exact mechanism of RA is still unknown, but various immune cytokines, signaling pathways and effector cells are involved. Disease-modifying antirheumatic drugs (DMARDs) are commonly used in RA treatment and classified into different categories. Nevertheless, RA treatment is based on a "trial-and-error" approach, and a substantial proportion of patients show failed therapy for each DMARD. Over the past decades, great efforts have been made to overcome treatment failure, including identification of biomarkers, exploration of the reasons for loss of efficacy, development of sequential or combinational DMARDs strategies and approval of new DMARDs. Here, we summarize these efforts, which would provide valuable insights for accurate RA clinical medication. While gratifying, researchers realize that these efforts are still far from enough to recommend specific DMARDs for individual patients. Precision medicine is an emerging medical model that proposes a highly individualized and tailored approach for disease management. In this review, we also discuss the potential of precision medicine for overcoming RA treatment failure, with the introduction of various cutting-edge technologies and big data.

First-in-human study of the safety, tolerability, pharmacokinetics, and pharmacodynamics of ALPN-101, a dual CD28/ICOS antagonist, in healthy adult subjects

ALPN-101 (ICOSL vIgD-Fc) is an Fc fusion protein of a human inducible T cell costimulatory ligand (ICOSL) variant immunoglobulin domain (vIgD) designed to inhibit the cluster of differentiation 28 (CD28) and inducible T cell costimulator (ICOS) pathways simultaneously. A first-in-human study evaluated the safety, tolerability, pharmacokinetics (PK), and pharmacodynamics (PD) of ALPN-101 in healthy adult subjects. ALPN-101 was generally well-tolerated with no evidence of cytokine release, clinically significant immunogenicity, or severe adverse events following single subcutaneous (SC) doses up to 3 mg/kg or single intravenous (IV) doses up to 10 mg/kg or up to 4 weekly IV doses of up to 1 mg/kg. ALPN-101 exhibited a dose-dependent increase in exposure with an estimated terminal half-life of 4.3-8.6 days and SC bioavailability of 60.6% at 3 mg/kg. Minimal to modest accumulation in exposure was observed with repeated IV dosing. ALPN-101 resulted in a dose-dependent increase in maximum target saturation and duration of high-level target saturation. Consistent with its mechanism of action, ALPN-101 inhibited cytokine production in whole blood stimulated by Staphylococcus aureus enterotoxin B ex vivo, as well as antibody responses to keyhole limpet hemocyanin immunization, reflecting immunomodulatory effects upon T cell and T-dependent B cell responses, respectively. In conclusion, ALPN-101 was well-tolerated in healthy subjects with dose-dependent PK and PD consistent with the known biology of the CD28 and ICOS costimulatory pathways. Further clinical development of ALPN-101 in inflammatory and/or autoimmune diseases is therefore warranted.

Associations between an expanded autoantibody profile and treatment responses to biologic therapies in patients with rheumatoid arthritis

BACKGROUND

Although biologics represent a major advance in rheumatoid arthritis (RA), many patients fail to achieve adequate responses to these agents. We examined whether combined positivity to three well-characterized autoantibodies predicts treatment response among RA patients initiating biologics.

METHODS

The study included biologic-naïve patients initiating anti-TNF treatment, biologic-exposed patients switching to rituximab or tocilizumab, and patients (biologic naïve or exposed) initiating abatacept. Rheumatoid factor (RF), anti-cyclic citrullinated peptide (CCP) antibody, and IgG antibodies to malondialdehyde-acetaldehyde (MAA) were measured using banked enrollment serum. The relationship between the number of autoantibodies positive (0-3) and treatment response (absolute improvement in 28-joint Disease Activity Score [DAS28-CRP] or improvement > 1.2) at 6 months was examined using multivariable linear and logistic regression.

RESULTS

Of 1,229 patients initiating biologics, 79% were women; 89% were Caucasian. The number of baseline RA-related autoantibodies positive was associated with improved treatment response in a dose-dependent fashion. Compared to patients seronegative for all autoantibodies, adjusting for covariates, those positive for all three were more than twice (OR 2.35; 95% CI 1.57-3.51) as likely to achieve DAS28 improvement > 1.2 units. Associations of autoantibody positivity with biologic treatment response were strongest for anti-CCP antibody, persisted in analyses limited to biologic naïve patients, and did not appear to differ markedly among different agents examined.

CONCLUSION

An expanded autoantibody profile appears to significantly predict RA treatment response to biologic treatment in a dose-dependent fashion. Incorporating these serologic profiles with additional biomarkers or other informative patient characteristics could provide an opportunity to personalize RA management.

Differential long-term retention of biological disease-modifying antirheumatic drugs in patients with rheumatoid arthritis by age group from the FIRST registry

BACKGROUND

The effectiveness and safety of biological disease-modifying antirheumatic drugs (bDMARDs) by age group (< 65, 65-74, and ≥ 75 years) are uncertain. We examined retention rates reflecting the effectiveness and safety of bDMARDs in actual clinical practice for clarifying optimal therapeutic strategies for rheumatoid arthritis (RA) by age groups.

METHODS

Data of patients who were treated with tumor necrosis factor inhibitors (TNFi), abatacept (ABA), and tocilizumab (TCZ) between February 2011 and April 2017 were collected from a prospective observational registry of RA patients. A total of 1362 patients were enrolled, of which 695 were aged < 65 years, 402 were aged 65-74 years, and 265 were aged ≥ 75 years. Primary outcome was the drug retention rate in adjusted data using inverse probability of treatment weighting based on generalized propensity scores.

RESULTS

In patients aged < 65 years, 3-year retention rates of TNFi, ABA, and TCZ were 43%, 47%, and 69%, respectively (ABA versus TCZ, p = 0.017; TNFi versus TCZ, p = 0.002). In patients aged 65-74 years, 3-year retention rates of TNFi, ABA, and TCZ were 44%, 53%, and 60%, respectively (TCZ versus TNFi, p = 0.034). In patients aged ≥ 75 years, 3-year retention rates for TNFi, ABA, and TCZ were 38%, 63%, and 58%, respectively (ABA versus TNFi, p = 0.017).

CONCLUSIONS

We found that the effectiveness and safety of TCZ were maximal in patients aged < 75 years and that patients aged ≥ 75 years might be suitable candidates for TCZ and ABA therapy. The use of therapeutic strategies appropriate to each age group might improve the outcomes of bDMARD therapy for RA.

High Proportion of Subjective Component to the Disease Activity Score is Associated with Favorable Response to Abatacept in Rheumatoid Arthritis

BACKGROUND

Response prediction of certain biologic agents for the treatment of rheumatoid arthritis (RA) remains an unmet need in real-world clinical practice. The contribution of patient-reported components to the 28-joint Disease Activity Score (DAS28) was termed DAS28-P and investigated as a predictor of response to biologic agents, mostly tumor necrosis factor inhibitors. We aimed to evaluate DAS28-P as a predictor of the European League Against Rheumatism (EULAR) response to abatacept in patients with RA.

METHODS

The study population was a prospective, observational, multicenter cohort of Korean patients with RA, who were followed up for a nationwide post-marketing surveillance study of abatacept. Correlation of DAS28-P with DAS28, change of DAS28, and EULAR response groups were evaluated. Logistic regression analysis was used to predict good-to-moderate EULAR response to abatacept in the study population.

RESULTS

A total of 341 patients were involved in the analysis stratified on the EULAR response criteria. Presence of comorbidities, previous exposure to biologic agents, baseline DAS28, three of its components (tender joint counts, global health visual analog scale, erythrocyte sedimentation rate), and baseline DAS28-P were significantly associated with EULAR response to abatacept at 6 months. Stratified upon EULAR response, a group with good-to-moderate response had a higher baseline value and lower interval change for DAS28-P. Logistic regression analysis showed that a DAS28-P cut-off of > 0.44 was more positively associated with good-to-moderate EULAR response with abatacept treatment than naivety to biologic agents.

CONCLUSIONS

The DAS28-P could be predictive of response to abatacept. A higher baseline DAS28-P is associated with a favorable therapeutic response to abatacept.

TRIAL REGISTRATION

Trial name, Korean Post-marketing Surveillance for Orencia^®. Trial registration number, NCT01583244. Registered on April 20, 2012.

Circulating Th17.1 cells as candidate for the prediction of therapeutic response to abatacept in patients with rheumatoid arthritis: An exploratory research

T-helper (Th)17.1 cells exhibit high pathogenicity in inflammatory diseases. This study aimed to identify the changes in the proportions of Th subsets, including Th17.1, which are associated with abatacept treatment response in Japanese patients with rheumatoid arthritis. On the basis of the results, we assessed whether Th17.1 is a potential cellular biomarker. Multicolor flow cytometry was used to determine the circulating Th subsets among CD4+ T lymphocytes in 40 patients with rheumatoid arthritis before abatacept treatment. All the patients received abatacept treatment for 24 weeks; changes in disease activity score, including 28-joint count C-reactive protein, and responsiveness indicated by other indices to abatacept treatment were evaluated according the European League Against Rheumatism criteria (good and moderate responders and nonresponders). The correlation between the abatacept responses and the proportions of Th subsets (baseline) was analyzed. Logistic regression analysis with inverse probability weighting method was performed to calculate the odds ratio adjusted for patient characteristics. The proportion of baseline Th17.1 cells was significantly lower in patients categorized as good responders than in those categorized as non-good responders (moderate responders and nonresponders; p = 0.0064). The decrease in 28-joint count C-reactive protein after 24 weeks of abatacept therapy showed a significant negative correlation with the proportion of Th17.1 cells. The adjusted odds ratio for achieving good response in patients with baseline Th17.1 levels below the median value was 14.6 (95% confidence interval, 2.9–72.3; p = 0.0021) relative to that in the remaining patients. The proportion of Th17.1 cells at baseline is a good candidate for predicting abatacept treatment response in Japanese patients. These novel findings may represent a significant step in the pursuit of precision medicine.

Using the Immunophenotype to Predict Response to Biologic Drugs in Rheumatoid Arthritis

Tumour necrosis factor (TNF)-α is a key mediator of inflammation in rheumatoid arthritis, and its discovery led to the development of highly successful anti-TNF therapy. Subsequently, other biologic drugs targeting immune pathways, namely interleukin-6 blockade, B cell depletion, and T cell co-stimulation blockade, have been developed. Not all patients respond to a biologic drug, leading to a knowledge gap between biologic therapies available and the confident prediction of response. So far, genetic studies have failed to uncover clinically informative biomarkers to predict response. Given that the targets of biologics are immune pathways, immunological study has become all the more pertinent. Furthermore, advances in single-cell technology have enabled the characterization of many leucocyte subsets. Studying the blood immunophenotype may therefore, define biomarker profiles relevant to each individual patient's disease and treatment outcome. This review summarises our current understanding of how immune biomarkers might be able to predict treatment response to biologic drugs.

T cells, natural killer cells, and γδT cells in a large patient cohort with rheumatoid arthritis: influence of age and anti-rheumatic therapy

Objective: The aim of this cohort study was to evaluate the distribution of natural killer (NK) cells and T-cell subsets, including γδT cells, in the peripheral blood of patients with rheumatoid arthritis (RA) in a large real-life patient cohort, taking into account the patients' demographics, disease characteristics, and anti-rheumatic therapy.Method: The study recruited 508 RA patients between November 2013 and August 2015. Lymphocyte differentiation using eight-colour flow cytometry (fluorescence-activated cell sorting) of the peripheral blood was performed for all patients. Clinical data, including age, gender, disease duration, serostatus, disease activity, antibody status, immunosuppressive therapy including use of different biological disease-modifying anti-rheumatic drugs (bDMARDs) and conventional synthetic DMARDs, were retrospectively assessed using electronic patient files. Multivariate regression analysis was performed to assess the effect of these variables on T-cell, NK-cell, and γδT-cell counts.Results: The median patient age was 61.0 years and 74.1% were female. The median disease duration of RA was 12.0 years. Median Disease Activity Score based on 28-joint count was 2.8 and 56.3% were treated with bDMARDs. There were no differences in immunosuppressive therapy between different age groups. While rituximab, abatacept, and tocilizumab had no influence on lymphocyte subdifferentiation, tumour necrosis factor (TNF) inhibitors and age significantly influenced the numbers of T cells, T-helper cells, T-NK cells, NK cells, and γδT cells.Conclusion: Age and TNF-inhibition therapy influence lymphocyte subdifferentiation in patients with RA. It may be prudent to use age- and therapy-adjusted standard values for lymphocyte subsets during clinical trials and treatment of RA.

Subcutaneous abatacept in rheumatoid arthritis: A real-life experience

Objectives

To assess the effectiveness, safety, and drug survival of subcutaneous (SC) abatacept (ABA) in a cohort of rheumatoid arthritis (RA) patients in a real-world setting.

Methods

This was a retrospective cohort study from 2014 to 2018 in which patients with RA (1987 ACR criteria) were included. Patients were evaluated at a single rheumatology outpatient center in Bogotá, Colombia. The patients were classified according to their treatment background: biological-naïve (n = 65), switched from IV to SC ABA administration (125 mg-wk) (n = 32), and inadequate response to biological DMARD (n = 62). The primary endpoint was a change in DAS28-CRP and RAPID3 from baseline to 12 months. A linear mixed effect model was used to correlate repeated measures. Adverse events were assessed and recorded during each visit to the rheumatology center. Several Cox proportional hazard regression models were used to test if there were any differences in drug survival curves based on seropositivity for rheumatoid factor (RF), and anti-Cyclic Citrullinated Peptide Antibodies (anti-CCP). Statistical analysis was done using software R version 3.4.4.

Results

A total of 159 patients were included. Baseline characteristics of patients were as follows: female gender 84%, median age of 54 years (IQR 16), median disease duration 10 years (11), RF positive 96%, anti-CCP positive 89%, erosive disease 55%, median DAS28-CRP 5.0 (2), and median RAPID3 17 (10). Concomitant use of methotrexate and SC ABA monotherapy were reported at 52% and 30% respectively. Demographics and disease characteristics were similar for all groups, except for baseline DAS28-CRP, and RAPID3 in the group that switched route of administration. The interaction between time and group was significant (p = 0.0073) for RAPID3. Infections, constitutional symptoms, and headaches were the most frequent AEs. Retention rate corresponded to 60% at 48 months. The most frequent reason for drug suspension was loss of efficacy. Median time of treatment for SC ABA was 31 months (IQR 30). The only association that reached statistical significance was anti-CCP concentration [Q1–Q4] (p = 0.005). According to the Cox proportional hazard regression model, there were significant differences between survival curves for Q1 (HR 0.15; 0.03–0.64 95% CI; p = 0.0096), and Q2 (HR 0.28; 0.08–0.92 95% CI; p = 0.0363) compared to the seronegative group.

Conclusions

The results showed an improvement in RA disease activity and physical function in patients under SC ABA treatment. Patients switching from IV to SC administration of ABA had lower activity and functional impairment at baseline. SC ABA demonstrated a good safety profile consistent with previously published data. Patients with baseline levels of anti-CCP antibody concentrations had better drug survival than seronegative patients.

•

Only a few studies have evaluated the effectiveness and safety of ABA in patients with RA in routine clinical practice.

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RAPID3 appears to be an attractive option for evaluating disease activity in RA patients in a real-life setting.

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SC administration of ABA demonstrates a safety profile consistent with previously published data.

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Prognostic factors for drug retention have not been explored thoroughly despite data for ABA being available from national registries.

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SC ABA survival tends to be better in a subset of anti-CCP seropositive patients with RA.

An imbalance in the T-helper phenotypes displayed by senescent CD4+CD28null T cells is associated with erosive arthritis (rhupus syndrome) in systemic lupus erythematosus

OBJECTIVE

The objective was to assess the proportion of Th1, Th2 and Th17 phenotypes in senescent CD4⁺CD28^null cells from patients with systemic lupus erythematosus (SLE) and its association with the pattern of joint involvement.

METHODS

This cross-sectional study was performed in SLE patients with erosive arthritis (rhupus) or nondeforming, nonerosive arthritis. Total CD4⁺CD28^null cells as well as the proportion of these cells expressing T-bet, GATA3 or RORγt were analyzed by color-flow cytometry. Serum osteopontin levels were measured by ELISA.

RESULTS

Eighteen SLE patients (nine with rhupus and nine with nonerosive arthritis) were studied. The percentage of CD4⁺CD28^null/CD4⁺ cells (17.7%, 10.3-25.0% versus 9.4%, 8.1-22.4%; P = 0.386) as well as the osteopontin levels (5800, 5,134-5995 pg/ml versus 5578, 5171-5717 pg/ml; P > 0.05) were similar in both groups. A higher percentage of CD4⁺CD28^nullT-bet⁺ cells (42.8%, 33.5-53.4% versus 30.0%, 23.3-34.2%) but a lower percentage of CD4⁺CD28^nullGATA3⁺ cells (3.1%, 1.7-5.6% versus 6.2%, 2.6-18.4%) was observed in patients with rhupus than in their counterparts ( P = 0.016). The frequency of CD4⁺CD28^nullRORγt⁺ cells was similar between groups.

CONCLUSIONS

In patients with rhupus, senescent CD4⁺CD28^null cells are preferentially polarized to a Th1 phenotype, whereas this is partial towards Th2 in lupus patients with a nonerosive arthritis pattern.

Lymphocytes as Biomarkers of Therapeutic Response in Rheumatic Autoimmune Diseases, Is It a Realistic Goal?

Many therapies are available for patients with rheumatoid arthritis (RA) while biological therapies have limited effects in patients with systemic lupus erythematosus (SLE) and primary Sjögren's syndrome (pSS). In both cases, biomarkers predicting drug response would be very useful to guide clinicians in their choice. We performed a systematic review to evaluate the value of lymphocyte phenotyping as a marker of therapeutic response. Of the 1063 articles retrieved, 39 fulfilled inclusion criteria and were included in the present review (25 for RA, 10 for SLE, and 4 for pSS). Lymphocyte phenotyping was described as a biomarker of therapeutic response in many studies, but most results could not be confirmed by independent teams using multivariate analysis. The most consistent result might be the association between rituximab response and the levels of memory B cells before therapy, although some studies were controversial. Thus, lymphocyte phenotyping cannot yet be proposed as a biomarker of response in rheumatic autoimmune diseases. The lack of reproducibility between studies may be explained by technical issues influencing lymphocyte phenotyping so standardization procedures should be developed for future studies. The patients' characteristics vary between studies, and large population studies, including a wide range of patients' characteristics and biomarkers, are required to provide predictive models for clinical outcomes. The use of new flow cytometry techniques such as single-cell mass cytometry technology might also help finder reliable biomarkers in the future.

Right drug, right patient, right time: aspiration or future promise for biologics in rheumatoid arthritis?

Individualising biologic disease-modifying anti-rheumatic drugs (bDMARDs) to maximise outcomes and deliver safe and cost-effective care is a key goal in the management of rheumatoid arthritis (RA). Investigation to identify predictive tools of bDMARD response is a highly active and prolific area of research. In addition to clinical phenotyping, cellular and molecular characterisation of synovial tissue and blood in patients with RA, using different technologies, can facilitate predictive testing. This narrative review will summarise the literature for the available bDMARD classes and focus on where progress has been made. We will also look ahead and consider the increasing use of 'omics' technologies, the potential they hold as well as the challenges, and what is needed in the future to fully realise our ambition of personalised bDMARD treatment.

Effector T-cells are expanded in systemic lupus erythematosus patients with high disease activity and damage indexes

Background and objectives T-cell activation may be one of the pathogenic mechanisms of systemic lupus erythematosus (SLE). After repeated antigenic stimulation, T-cells undergo different modifications, leading to the differentiation into effector memory T-cells (CCR7-CD45RA-) and terminally differentiated effector memory (TDEM) T-cells (CCR7-CD45RA+). Similarly, down-modulation of CD28 may lead to the expansion of the CD28- T-cells, a subpopulation with peculiar effector activities. The aim of this study was the characterization of T-cell phenotype in a cohort of patients with SLE according to disease activity and damage index. Materials and methods Phenotypic analysis of peripheral blood T lymphocytes of 51 SLE patients and 21 healthy controls was done by flow-cytometry. SLE disease activity was evaluated by SLE Disease Activity Index-2000 (SLEDAI-2K) and damage by the Systemic Lupus International Collaborating Clinics/American College of Rheumatology damage index (SDI). The variations between different groups were evaluated by Mann-Whitney test. Bonferroni correction was applied to adjust for multiple comparisons ( p^adj). Spearman rank test was used to evaluate the correlations between quantitative variables. Results CD4+ lymphopenia was found among SLE patients. Patients showed a trend for a higher percentage of TDEM among the CD4+ T-cell subpopulation in comparison with healthy controls ( p = .04). SLE patients were divided into two groups according to disease activity: patients with SLEDAI-2K ≥ 6 ( n = 13) had a higher percentage of circulating CD4+ T-cells with CD28- phenotype ( p^adj= .005) as well as those with an effector memory ( p^adj= .004) and TDEM ( p^adj= .002) phenotype and a trend of decrease of regulatory T-cells (TREGs) ( p = .02), in comparison with patients with low disease activity ( n = 38). Patients with damage (SDI ≥ 1) tended to show an expansion of TDEM among CD4+ T-cells as compared with patients with no damage ( p = .01). In SLE patients an inverse correlation was found between the percentages of TREGs and those of TDEM ( p < .01) or CD4 + CD28- ( p < .01) T-cells. Conclusions CD4+ T-cell subpopulations displaying phenotype characteristics of effector lymphocytes are proportionally expanded in patients with active SLE and a higher damage index. These findings may suggest a role of effector T-cells in the pathogenesis of the disease and in the mechanisms of damage in SLE.

Identification of biomarkers of response to abatacept in patients with SLE using deconvolution of whole blood transcriptomic data from a phase IIb clinical trial

Objective

To characterise patients with active SLE based on pretreatment gene expression-defined peripheral immune cell patterns and identify clusters enriched for potential responders to abatacept treatment.

Methods

This post hoc analysis used baseline peripheral whole blood transcriptomic data from patients in a phase IIb trial of intravenous abatacept (~10 mg/kg/month). Cell-specific genes were used with a published deconvolution algorithm to identify immune cell proportions in patient samples, and unsupervised consensus clustering was generated. Efficacy data were re-analysed.

Results

Patient data (n=144: abatacept: n=98; placebo: n=46) were grouped into four main clusters (C) by predominant characteristic cells: C1—neutrophils; C2—cytotoxic T cells, B-cell receptor-ligated B cells, monocytes, IgG memory B cells, activated T helper cells; C3—plasma cells, activated dendritic cells, activated natural killer cells, neutrophils; C4—activated dendritic cells, cytotoxic T cells. C3 had the highest baseline total British Isles Lupus Assessment Group (BILAG) scores, highest antidouble-stranded DNA autoantibody levels and shortest time to flare (TTF), plus trends in favour of response to abatacept over placebo: adjusted mean difference in BILAG score over 1 year, −4.78 (95% CI −12.49 to 2.92); median TTF, 56 vs 6 days; greater normalisation of complement component 3 and 4 levels. Differential improvements with abatacept were not seen in other clusters, except for median TTF in C1 (201 vs 109 days).

Conclusions

Immune cell clustering segmented disease severity and responsiveness to abatacept. Definition of immune response cell types may inform design and interpretation of SLE trials and treatment decisions.

Trial registration number

NCT00119678; results.

Prediction of Response to Targeted Treatment in Rheumatoid Arthritis

Rheumatoid arthritis is an autoimmune syndrome presenting with chronic inflammation of the joints. Patients with the same diagnosis can present with different phenotypes. In some patients severe joint inflammation and early joint destruction are observed, whereas a milder phenotype can be seen in others. Conversely, patients with the same signs and symptoms may exhibit different immunological and molecular abnormalities. Since the introduction of early treatment in clinical practice, the treat to target principle, and new medicines such as biologic disease-modifying antirheumatic drugs, clinical remission can be achieved early in the disease course, albeit not in all patients. The clinical response and efficacy of biologic disease-modifying antirheumatic drugs vary among different individuals. Therefore, there is a need to develop a more personalized approach toward treatment to achieve rapid remission in every patient to prevent disability and restore and maintain quality of life, without unnecessary adverse effects, in a cost-effective manner. The latest data from explorative studies of predictive markers of response are discussed here, together with a preliminary treatment algorithm based on currently available knowledge.

Pre-silencing of genes involved in the electron transport chain (ETC) pathway is associated with responsiveness to abatacept in rheumatoid arthritis

Background

In the current context of personalized medicine, one of the major challenges in the management of rheumatoid arthritis (RA) is to identify biomarkers that predict drug responsiveness. From the European APPRAISE trial, our main objective was to identify a gene expression profile associated with responsiveness to abatacept (ABA) + methotrexate (MTX) and to understand the involvement of this signature in the pathophysiology of RA.

Methods

Whole human genome microarrays (4 × 44 K) were performed from a first subset of 36 patients with RA. Data validation by quantitative reverse-transcription (qRT)-PCR was performed from a second independent subset of 32 patients with RA. Gene Ontology and WikiPathways database allowed us to highlight the specific biological mechanisms involved in predicting response to ABA/MTX.

Results

From the first subset of 36 patients with RA, a combination including 87 transcripts allowed almost perfect separation between responders and non-responders to ABA/MTX. Next, the second subset of patients 32 with RA allowed validation by qRT-PCR of a minimal signature with only four genes. This latter signature categorized 81% of patients with RA with 75% sensitivity, 85% specificity and 85% negative predictive value. This combination showed a significant enrichment of genes involved in electron transport chain (ETC) pathways. Seven transcripts from ETC pathways (NDUFA6, NDUFA4, UQCRQ, ATP5J, COX7A2, COX7B, COX6A1) were significantly downregulated in responders versus non-responders to ABA/MTX. Moreover, dysregulation of these genes was independent of inflammation and was specific to ABA response.

Conclusion

Pre-silencing of ETC genes is associated with future response to ABA/MTX and might be a crucial key to susceptibility to ABA response.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-017-1319-8) contains supplementary material, which is available to authorized users.

Phenotypic characteristics of aged CD4+ CD28null T lymphocytes are determined by changes in the whole-genome DNA methylation pattern

Aging is associated with a progressive loss of the CD28 costimulatory molecule in CD4⁺ lymphocytes (CD28^null T cells), which is accompanied by the acquisition of new biological and functional properties that give rise to an impaired immune response. The regulatory mechanisms that govern the appearance and function of this cell subset during aging and in several associated inflammatory disorders remain controversial. Here, we present the whole‐genome DNA methylation and gene expression profiles of CD28^null T cells and its CD28⁺ counterpart. A comparative analysis revealed that 296 genes are differentially methylated between the two cell subsets. A total of 160 genes associated with cytotoxicity (e.g. GRZB,TYROBP, and RUNX3) and cytokine/chemokine signaling (e.g. CX3CR1,CD27, and IL‐1R) are demethylated in CD28^null T cells, while 136 de novo‐methylated genes matched defects in the TCR signaling pathway (e.g. ITK,TXK,CD3G, and LCK). TCR‐landscape analysis confirmed that CD28^null T cells have an oligo/monoclonal expansion over the polyclonal background of CD28⁺ T cells, but feature a Vβ family repertoire specific to each individual. We reported that CD28^null T cells show a preactivation state characterized by a higher level of expression of inflammasome‐related genes that leads to the release of IL‐1β when activated. Overall, our results demonstrate that CD28^null T cells have a unique DNA methylation landscape, which is associated with differences in gene expression, contributing to the functionality of these cells. Understanding these epigenetic regulatory mechanisms could suggest novel therapeutic strategies to prevent the accumulation and activation of these cells during aging.

Expansions of Cytotoxic CD4+CD28- T Cells Drive Excess Cardiovascular Mortality in Rheumatoid Arthritis and Other Chronic Inflammatory Conditions and Are Triggered by CMV Infection

A large proportion of cardiovascular (CV) pathology results from immune-mediated damage, including systemic inflammation and cellular proliferation, which cause a narrowing of the blood vessels. Expansions of cytotoxic CD4⁺ T cells characterized by loss of CD28 (“CD4⁺CD28⁻ T cells” or “CD4⁺CD28^null cells”) are closely associated with cardiovascular disease (CVD), in particular coronary artery damage. Direct involvement of these cells in damaging the vasculature has been demonstrated repeatedly. Moreover, CD4⁺CD28⁻ T cells are significantly increased in rheumatoid arthritis (RA) and other autoimmune conditions. It is striking that expansions of this subset beyond 1–2% occur exclusively in CMV-infected people. CMV infection itself is known to increase the severity of autoimmune diseases, in particular RA and has also been linked to increased vascular pathology. A review of the recent literature on immunological changes in CVD, RA, and CMV infection provides strong evidence that expansions of cytotoxic CD4⁺CD28⁻ T cells in RA and other chronic inflammatory conditions are limited to CMV-infected patients and driven by CMV infection. They are likely to be responsible for the excess CV mortality observed in these situations. The CD4⁺CD28⁻ phenotype convincingly links CMV infection to CV mortality based on a direct cellular-pathological mechanism rather than epidemiological association.

Simplified Disease Activity Index remission at month 6 is an independent predictor of functional and structural remissions at month 12 during abatacept treatment in patients with rheumatoid arthritis: A multi-center, prospective cohort study in Japan

OBJECTIVE

To evaluate association of clinical remission at month 6 with functional and structural remissions at month 12 during abatacept treatment in patients with rheumatoid arthritis (RA).

METHODS

This 12-month prospective, multicenter cohort study enrolled 168 patients with RA who started abatacept. Outcomes were assessed using composite measures, quality of life indices, and the van der Heijde-modified total Sharp score (mTSS). The logistic regression analysis was applied to identify factors associated with outcomes and their odds ratios (OR) with 95% confidence interval (95% CI).

RESULTS

At month 6 and 12, 21.4% and 26.2% of the patients achieved Simplified Disease Activity Index (SDAI) remission (SDAI <3.3), and 40.6% and 41.7% achieved Health Assessment Questionnaire-Disability Index (HAQ-DI <0.5) remission. Among 129 patients whose mTSS progression was evaluated at month 12, 83 (64.3%) achieved structural remission (ΔmTSS ≤0.5 for 12 months). SDAI remission at month 6 was identified as a significant predictor of both functional (OR, 3.732; 95% CI, 1.328-10.489) and structural remissions (OR, 4.301; 95% CI, 1.298-14.243) at month 12 after adjusting for covariates.

CONCLUSIONS

Aiming for SDAI remission at month 6 is an appropriate strategy to obtain good functional and structural outcomes at month 12.

STAT6 and STAT1 Pathway Activation in Circulating Lymphocytes and Monocytes as Predictor of Treatment Response in Rheumatoid Arthritis

Objective

To find novel predictors of treatment response to disease-modifying antirheumatic drugs (DMARDs), we studied activation of STAT (signal transducers and activators of transcription) 6 and 1 in circulating leukocytes of patients with rheumatoid arthritis (RA).

Methods

19 patients with untreated recent-onset RA, 16 patients with chronic RA irresponsive to synthetic DMARDs and 37 healthy volunteers provided blood samples for whole blood flow cytometric determination of intracellular STAT6 and STAT1 phosphorylation, expressed as relative fluorescence units, in response to IL-4 and IFN-γ, respectively. Phosphorylation was restudied and treatment response (according to European League Against Rheumatism) determined after 1-year treatment with synthetic DMARDs in recent-onset RA and with biological DMARD in synthetic DMARD-irresponsive RA. Estimation-based exact logistic regression was used to investigate relation of baseline variables to treatment response. 95% confidence intervals of means were estimated by bias-corrected bootstrapping and the significance between baseline and follow-up values was calculated by permutation test.

Results

At baseline, levels of phosphorylated STAT6 (pSTAT6) induced by IL-4 in monocytes were higher in those who achieved good treatment response to synthetic DMARDs than in those who did not among patients with untreated RA (OR 2.74, 95% CI 1.05 to 9.47), and IFN-γ -stimulated lymphocyte pSTAT1 levels were higher in those who achieved good treatment response to a biological drug than in those who did not among patients with chronic RA (OR 3.91, 95% CI 1.12 to 20.68). During follow-up, in recent-onset RA patients with good treatment response to synthetic DMARDS, the lymphocyte pSTAT6 levels decreased (p = 0.011), and, consequently, the ratio of pSTAT1/pSTAT6 in lymphocytes increased (p = 0.042).

Conclusion

Cytokine-stimulated STAT6 and STAT1 phosphorylation in circulating leukocytes was associated with treatment response to DMARDs in this pilot study. The result, if confirmed in larger studies, may aid in developing personalized medicine in RA.

HLA-G and CD8+ regulatory T cells in the inflammatory environment of pre-eclampsia

During pregnancy, the maternal immune system is tolerant to foetal antigens via the engagement of immune regulatory mechanisms. Failure in regulating the maternal immunity to foetal antigens may lead to pre-eclampsia (PE). We addressed the role of HLA-G gene polymorphisms and protein expression as well as regulatory T cells and Th1/Th2/Th17 cytokines in healthy and pathological pregnancies. Blood samples from 26 pregnant women with PE, 25 non-PE and 7 strictly healthy pregnant women were assessed. PBMCs were phenotyped for early activation markers (CD25 and CD69), regulatory T-cell markers (CD8⁺CD28^- and CD4⁺CD25^highFoxp3⁺), ILT-2 (HLA-G receptor) and HLA-G. Lymphocyte proliferation was estimated and levels of IL-2, IL-4, IL-6, IL-10, IFN-γ, TNF-α and IL-17 were measured. HLA-G polymorphisms (rs66554220 and rs1063320) were genotyped by PCR. PE women exhibited low levels of HLA-G in PBMCs and low frequency of regulatory CD8⁺CD28^- T cells. High amounts of the pro-inflammatory cytokines IL-17, IL-2 and TNF-α as well as IL-4 and IL-10 and an increased proliferative cell activation profile were observed in PE. The allelic and genotypic frequencies of the HLA-G gene polymorphisms and the frequency of CD4⁺CD25^highFoxp3⁺ T cells did not vary among the groups. Our data suggest that the cytokine imbalance presented in PE is associated with a deficient immune regulatory profile, contributing to an impaired immune tolerance between mother and foetus.

Rheumatoid Arthritis, Immunosenescence and the Hallmarks of Aging

Age is the most important risk factor for the development of infectious diseases, cancer and chronic inflammatory diseases including rheumatoid arthritis (RA). The very act of living causes damage to cells. A network of molecular, cellular and physiological maintenance and repair systems creates a buffering capacity against these damages. Aging leads to progressive shrinkage of the buffering capacity and increases vulnerability. In order to better understand the complex mammalian aging processes, nine hallmarks of aging and their interrelatedness were recently put forward.

RA is a chronic autoimmune disease affecting the joints. Although RA may develop at a young age, the incidence of RA increases with age. It has been suggested that RA may develop as a consequence of premature aging (immunosenescence) of the immune system. Alternatively, premature aging may be the consequence of the inflammatory state in RA. In an effort to answer this chicken and egg conundrum, we here outline and discuss the nine hallmarks of aging, their contribution to the pre-aged phenotype and the effects of treatment on the reversibility of immunosenescence in RA.

Predictive factors of abatacept therapy discontinuation in patients with rheumatoid arthritis

The aim of this paper was to look for predictors of abatacept (ABA) therapy discontinuation in patients with rheumatoid arthritis (RA). Seventy-one RA patients treated with ABA were followed up. Demographical, clinical, and laboratory parameters of the patients, including peripheral blood T and B cell populations, different rheumatoid factor and anti-cyclic citrullinated peptide autoantibodies isotypes, and serum free light chains were evaluated. Comparing patients who discontinued ABA with those still in therapy we observed: a higher proportion of smokers (51.9 vs 25.6 %; p = 0.03); a non significant lower proportion of anti-cyclic citrullinated peptide positivity (76 vs 89.5 %; p = 0.13); a lower proportion of terminally differentiated effector memory cells (TDEM) among total CD8+ T lymphocytes at baseline (22.0 % (7.8-39.2) vs 38.7 % (20.7-55.9); p = 0.002). Logistic multivariate analysis showed that only the proportion of CD8+TDEM T cells was an independent predictive factor of therapy discontinuation (OR (95 % IC) = 6.2 (1.2 to 30.8); p = 0.026). Receiver-operating characteristic analysis showed a significant performance of this biomarker for prediction of therapy discontinuation (using a cut-off of 30.6 %: AUC: 0.760 ± 0.07; p = 0.002). Patients with a low proportion of CD8+TDEM at baseline had a higher probability of discontinuing the treatment during time (log-rank test: p < 0.01). T cell characterization for identification of TDEM CD8+ T cells might be a useful test to predict discontinuation of ABA therapy.

CTLA4-Ig in B7-1-positive diabetic and non-diabetic kidney disease

Diabetic kidney disease (DKD) is the leading cause of end-stage renal disease in the Western world. Standard treatments have ultimately proven ineffective in blocking DKD progression, thus necessitating the design of new therapies to complement glycaemic and blood pressure control. High glucose levels upregulate the immune-related molecule B7-1 in podocytes, and such an event may play a relevant role in DKD onset, suggesting that B7-1 is a suitable therapeutic target for DKD. CTLA4-Ig is a clinically available fusion protein, approved for the treatment of some autoimmune diseases, which binds B7-1 and blocks its signalling. We have previously demonstrated that CTLA4-Ig restores the physiological structure and cellular motility of podocytes challenged with high glucose in vitro and abrogates the onset of proteinuria in murine models of DKD in vivo. Notably, these beneficial effects occurred independently of any systemic immunological effects of CTLA4-Ig. While the expression of B7-1 on podocytes raises questions regarding the very nature of the podocyte as we know it, the preliminary positive effect of CTLA4-Ig on proteinuria in preclinical models and the evidence of B7-1 expression in kidney biopsies of diabetic individuals suggest a potential novel indication for CTLA4-Ig in DKD. Nonetheless, recent reports of problems with detecting podocyte B7-1 and of inconsistent therapeutic efficacy of CTLA4-Ig in proteinuric patients highlight the necessity to establish uniformly accepted protocols for the detection of B7-1 and underline the need for randomised trials with CTLA4-Ig in kidney diseases.

Phenotype modifications of T-cells and their shift toward a Th2 response in patients with systemic lupus erythematosus supplemented with different monthly regimens of vitamin D

BACKGROUND

Vitamin D receptor is constitutively expressed on the lymphocyte surface. Recent studies highlight that vitamin D may exert actions on T-cells, inhibiting Th1 and Th17 response and enhancing Th2 and T-regulatory (T-reg) function.

METHODS

Thirty-four patients with systemic lupus erythematosus (SLE) were randomly enrolled in a two-year prospective study. In the first year, 16 patients were supplemented with an intensive regimen of cholecalciferol (IR) (300.000 UI of cholecalciferol at baseline and 50.000 UI/monthly as maintenance, 850.000 UI annually), whereas 18 with a standard regimen (SR) (25.000 UI of cholecalciferol monthly, 300.000 UI annually). During the second year, patients were switched to the other arm of treatment. Phenotypic analysis of peripheral T lymphocyte and the quantification of cytokine production from peripheral blood mononuclear cells (PBMCs) were evaluated by flow cytometry.

RESULTS

At baseline, no significant difference between the two groups emerged among main T-cell subtypes. Over two years of treatment, we saw an increase in the number of T-reg cells, in the total amount of CD4+CD45RA+CCR7- T-cells, whereas a significant reduction of CD8+CD28- T-cells was observed. In addition, the analysis of PBMCs from eight patients following the IR showed the reduction of the IFN-γ/IL-4 ratio (p = 0.01) among CD8+ T-cells after 12 months.

CONCLUSIONS

After a long-term of monthly treatment with vitamin D in SLE patients, an enhancement of T-reg cells and the production of Th2 cytokines should be expected.

Immune cell profiling to guide therapeutic decisions in rheumatic diseases

Biomarkers are needed to guide treatment decisions for patients with rheumatic diseases. Although the phenotypic and functional analysis of immune cells is an appealing strategy for understanding immune-mediated disease processes, immune cell profiling currently has no role in clinical rheumatology. New technologies, including mass cytometry, gene expression profiling by RNA sequencing (RNA-seq) and multiplexed functional assays, enable the analysis of immune cell function with unprecedented detail and promise not only a deeper understanding of pathogenesis, but also the discovery of novel biomarkers. The large and complex data sets generated by these technologies--big data--require specialized approaches for analysis and visualization of results. Standardization of assays and definition of the range of normal values are additional challenges when translating these novel approaches into clinical practice. In this Review, we discuss technological advances in the high-dimensional analysis of immune cells and consider how these developments might support the discovery of predictive biomarkers to benefit the practice of rheumatology and improve patient care.

Prognostic factors for abatacept retention in patients who received at least one prior biologic agent: an interim analysis from the observational, prospective ACTION study

BACKGROUND

The emergence of new therapies for the treatment of rheumatoid arthritis (RA), the paucity of head-to-head studies, and the heterogeneous nature of responses to current biologics highlight the need for the identification of prognostic factors for treatment response and retention in clinical practice. Prognostic factors for patient retention have not been explored thoroughly despite data for abatacept and other biologics being available from national registries. Real-world data from the ACTION study may supplement the findings of randomized controlled trials and show how abatacept is used in clinical practice. The aim of this interim analysis was to identify prognostic factors for abatacept retention in patients with RA who received at least one prior biologic agent.

METHODS

A large, international, non-interventional cohort of patients with moderate-to-severe RA who initiated intravenous abatacept in Canada and Europe (May 2008-January 2011) enrolled in the ACTION study. Potential prognostic factors for retention in this interim analysis (data cut-off February 2012; including patients from Canada, Germany, Greece, and Italy) were baseline demographics and disease characteristics, medical history, and previous and concomitant medication. Clinically relevant variables with p ≤ 0.20 in univariate analysis and no collinearity were entered into a Cox proportional hazards regression model, adjusted for clustered data. Variables with p ≤ 0.10 were retained in the final model (backward selection).

RESULTS

The multivariate model included 834 patients. Anti-cyclic citrullinated peptide (CCP) antibody positivity (hazard ratio [95% confidence interval]: 0.55 [0.40, 0.75], p < 0.001), failure of <2 prior anti-tumor necrosis factors (TNFs) (0.71 [0.56, 0.90], p = 0.005 versus ≥2 prior anti-TNFs), and cardiovascular comorbidity at abatacept initiation (0.48 [0.28, 0.83], p = 0.009) were associated with lower risk of abatacept discontinuation. Patients in Greece and Italy were less likely to discontinue abatacept than patients in Germany and Canada (Greece: 0.30 [0.16, 0.58]; Italy: 0.50 [0.33, 0.76]; Canada: 1.04 [0.78, 1.40], p < 0.001 versus Germany).

CONCLUSIONS

Real-world prognostic factors for abatacept retention include anti-CCP positivity and fewer prior anti-TNF failures. Differences in retention rates between countries may reflect differences in healthcare systems. The finding that abatacept has potential advantages in patients with cardiovascular comorbidities needs to be confirmed in further research.

Reduced T-cell repertoire restrictions in abatacept-treated rheumatoid arthritis patients

Background

CD28^neg T cells, which display functional characteristic of oligoclonally expanded cytotoxic memory T lymphocytes, are believed to be pathologically relevant in rheumatoid arthritis manifestation. The CD28 co-stimulation blockade by abatacept can prevent the generation of CD28^neg T-cell populations in these patients.

Methods

Samples were obtained before and after 12 months of abatacept therapy. T-cell phenotype and T-cell receptor diversity were evaluated by flow cytometry and complementarity-determining region-3 spectratyping, respectively, while telomerase reverse-transcriptase gene level was measured by real-time PCR.

Results

Abatacept induces a decrease of the percentage and number of CD4⁺CD28^neg T cells and a reduction of T-cell repertoire restrictions; these features are directly correlated. Thymic output and telomerase activity are not modified by the therapy.

Conclusions

Abatacept-induced decrease of peripheral T-cell repertoire restrictions can due to a reduced generation of senescent, chronically stimulated CD4⁺CD28^neg T cells.

Electronic supplementary material

The online version of this article (doi:10.1186/s12967-014-0363-2) contains supplementary material, which is available to authorized users.

Reduction in CD4 central memory T-cell subset in costimulation modulator abatacept-treated patients with recent-onset type 1 diabetes is associated with slower C-peptide decline

We previously reported that continuous 24-month costimulation blockade by abatacept significantly slows the decline of β-cell function after diagnosis of type 1 diabetes. In a mechanistic extension of that study, we evaluated peripheral blood immune cell subsets (CD4, CD8-naive, memory and activated subsets, myeloid and plasmacytoid dendritic cells, monocytes, B lymphocytes, CD4(+)CD25(high) regulatory T cells, and invariant NK T cells) by flow cytometry at baseline and 3, 6, 12, 24, and 30 months after treatment initiation to discover biomarkers of therapeutic effect. Using multivariable analysis and lagging of longitudinally measured variables, we made the novel observation in the placebo group that an increase in central memory (CM) CD4 T cells (CD4(+)CD45R0(+)CD62L(+)) during a preceding visit was significantly associated with C-peptide decline at the subsequent visit. These changes were significantly affected by abatacept treatment, which drove the peripheral contraction of CM CD4 T cells and the expansion of naive (CD45R0(-)CD62L(+)) CD4 T cells in association with a significantly slower rate of C-peptide decline. The findings show that the quantification of CM CD4 T cells can provide a surrogate immune marker for C-peptide decline after the diagnosis of type 1 diabetes and that costimulation blockade may exert its beneficial therapeutic effect via modulation of this subset.

Abatacept (cytotoxic T lymphocyte antigen 4-immunoglobulin) improves B cell function and regulatory T cell inhibitory capacity in rheumatoid arthritis patients non-responding to anti-tumour necrosis factor-α agents

The use of biological agents combined with methotrexate (MTX) in rheumatoid arthritis (RA) patients has strongly improved disease outcome. In this study, the effects of abatacept on the size and function of circulating B and T cells in RA patients not responding to anti-tumour necrosis factor (TNF)-α have been analysed, with the aim of identifying immunological parameters helpful to choosing suitable tailored therapies. We analysed the frequency of peripheral B and T cell subsets, B cell function and T regulatory cell (Treg ) inhibitory function in 20 moderate/severe RA patients, according to the European League Against Rheumatism (EULAR)/American College of Rheumatology (ACR) criteria, primary non-responders to one TNF-α blocking agent, who received abatacept + MTX. Patients were studied before and 6 months after therapy. We found that abatacept therapy significantly reduced disease activity score on 44 joints (DAS)/erythrocyte sedimentation rate (ESR) values without causing severe side effects. The size of the circulating B and T cell compartments in RA patients was not significantly different from healthy donors, but B cell proliferation and plasma cell differentiation was impaired before therapy and restored by abatacept. While Treg cell frequency was normal, its inhibitory function was absent before therapy and was partially recovered 6 months after abatacept. B and Treg cell function is impaired in RA patients not responding to the first anti-TNF-α agent. Abatacept therapy was able to rescue immune function and led to an effective and safe clinical outcome, suggesting that RA patients, in whom anti-TNF-α failed, are immunologically prone to benefit from an agent targeting a different pathway.

A critical evaluation of the role of subcutaneous abatacept in the treatment of rheumatoid arthritis: patient considerations

There are now more therapeutic options for the treatment of rheumatoid arthritis (RA) than ever before, involving a range of mechanisms of action and different routes of administration. The T-cell costimulation modulator abatacept is the first biologic therapy for RA to be available in both subcutaneous (SC) and intravenous (IV) formulations. This review evaluates the utility of SC abatacept, with a particular focus on patient-reported outcomes, including physical function, pain, fatigue, and quality of life. Practical questions relating to the clinical use of SC abatacept are also addressed, including the relevance of abatacept’s mechanism of action; whether IV and SC abatacept are comparable; if patients can easily switch from IV to SC abatacept; whether an IV loading dose is needed; and if temporary treatment interruptions or lack of concomitant methotrexate can affect efficacy or safety. Topics that are of particular concern to patients when using SC biologics, such as injection-site reactions, are also discussed. Observational data from registries and meta-analyses of clinical studies suggest comparable clinical efficacy between biologic disease-modifying antirheumatic drugs; however, such analyses rarely focus on key determinants of patient quality of life such as pain, fatigue, and physical function. The head-to-head AMPLE study is one of the first studies powered to directly compare two biologics in patients with RA. Patient-reported outcomes from year 1 of the ongoing study are evaluated, demonstrating comparable improvements in physical function, pain, fatigue, Short Form-36 Health Survey, and Routine Assessment of Patient Index Data 3 scores between SC abatacept and SC adalimumab when administered with concomitant methotrexate. In summary, the data presented herein show that the SC formulation of abatacept provides a valuable addition to the range of available therapy options for patients with RA, capable of significantly improving key patient considerations such as pain, disability, loss of function, fatigue, and quality of life.

Predictive factors of response to biological disease modifying antirheumatic drugs: towards personalized medicine

Many therapies are now available for patients with rheumatoid arthritis (RA) who have an inadequate response to methotrexate including tumor necrosis factor inhibitors, abatacept, tocilizumab, and rituximab. Clinical response to drugs varies widely between individuals. A part of this variability is due to the characteristics of the patient such as age, gender, concomitant therapies, body mass index, or smoking status. Clinical response also depends on disease characteristics including disease activity and severity and presence of autoantibodies. Genetic background, cytokine levels, and immune cell phenotypes could also influence biological therapy response. This review summarizes the impact of all those parameters on response to biological therapies.

Immune checkpoint receptors in regulating immune reactivity in rheumatic disease

Immune checkpoint regulators are critical modulators of the immune system, allowing the initiation of a productive immune response and preventing the onset of autoimmunity. Co-inhibitory and co-stimulatory immune checkpoint receptors are required for full T-cell activation and effector functions such as the production of cytokines. In autoimmune rheumatic diseases, impaired tolerance leads to the development of diseases such as rheumatoid arthritis, systemic lupus erythematosus, and Sjogren's syndrome. Targeting the pathways of the inhibitory immune checkpoint molecules CD152 (cytotoxic T lymphocyte antigen-4) and CD279 (programmed death-1) in cancer shows robust anti-tumor responses and tumor regression. This observation suggests that, in autoimmune diseases, the converse strategy of engaging these molecules may alleviate inflammation owing to the success of abatacept (CD152-Ig) in rheumatoid arthritis patients. We review the preclinical and clinical developments in targeting immune checkpoint regulators in rheumatic disease.

Advances in CTLA-4-Ig-mediated modulation of inflammatory cell and immune response activation in rheumatoid arthritis

Rheumatoid arthritis (RA) is a multifactorial and polygenic immune-mediated disease, the pathogenesis of which involves different cell types. T and B lymphocytes, macrophages, endothelial cells, fibroblasts and osteoclasts have all been implicated in mediating the production of autoantibodies, proinflammatory cytokines and ultimately bone erosions. Cytotoxic T lymphocyte-associated antigen 4 immunoglobulin fusion protein (CTLA-4-Ig, abatacept) is a unique biologic agent targeting the co-stimulatory molecules CD80/CD86, and is indicated for the treatment of moderate-to-severe RA in patients who have had an inadequate response to one or more disease-modifying anti-rheumatic drugs, including methotrexate or anti-tumor necrosis factor agents. There is a growing body of evidence that, through selective modulation of the CD80/CD86 co-stimulatory molecules expressed by a variety of activated cell types, CTLA-4-Ig may inhibit the pathogenic RA process at several levels, both directly and indirectly. Here, we provide an overview of recent mechanistic studies of the action of CTLA-4-Ig on different cell types involved in mediating inflammation and joint damage in RA.

A randomized controlled trial to evaluate inhibition of T-cell costimulation in allergen-induced airway inflammation

RATIONALE

T lymphocytes are important in the pathogenesis of allergic asthma. Costimulation through CD28 is critical for optimal activation of T cells, and inhibition of this pathway with CTLA4Ig has been shown to be effective in preventing airway inflammation and hyperresponsiveness in animal models of asthma. Abatacept, a humanized version of CTLA4Ig, has been approved for treatment of rheumatoid arthritis, providing the opportunity to test whether inhibition of costimulation is an effective strategy to treat people with asthma.

OBJECTIVES

To determine if 3 months of treatment with abatacept reduced allergen-induced airway inflammation in people with mild atopic asthma.

METHODS

Randomized, placebo-controlled, double-blinded study. Bronchoscopically directed segmental allergen challenge was performed on 24 subjects followed by bronchoalveolar lavage 48 hours later. Subjects were randomized 1:1 to receive abatacept or placebo, followed by a second allergen challenge protocol after 3 months of study drug.

MEASUREMENTS AND MAIN RESULTS

There was no significant reduction in allergen-induced eosinophilic inflammation in the abatacept-treated group compared with placebo (17.71% ± 17.25% vs. 46.39% ± 29.21%; P = 0.26). In addition, we did not detect an effect of abatacept on FEV1, provocative concentration of methacholine sufficient to induce a 20% decline in FEV1, or asthma symptoms. Subjects treated with abatacept had an increased percentage of naive and a corresponding decrease in memory CD4(+) T cells in the blood compared with placebo.

CONCLUSIONS

Inhibition of CD28-mediated costimulation with abatacept does not seem to alter the inflammatory response to segmental allergen challenge or clinical measures of asthma symptoms in people with mild atopic asthma. Clinical trial registered with ClinicalTrials.gov (NCT 00784459).

[Personalized medicine for rheumatoid arthritis : serological and clinical patient profiles to optimize B and T cell targeted therapy]

Nowadays B and T-cell directed biologics in addition to TNF inhibitors are established as effective and safe treatment options for rheumatoid arthritis. As shown by the approval of rituximab for the treatment of systemic vasculitis, these drugs can also be useful for the treatment of other systemic autoimmune diseases; however, to optimize therapeutic strategies, predictive factors for treatment response as well as a good characterized safety profile are essential. So far implementation of real personalized medicine is not feasible in the field of rheumatology, but first biomarkers have already been identified and provide promising results. In this context, it has been shown that a B-cell directed therapy with rituximab is more effective in seropositive patients with rheumatoid arthritis. In addition, characterization of the cytokine milieu as well as of circulating and tissue infiltrating B and T-cell subsets might be useful for prediction of treatment response in the near future.

Pathogenic features of CD4+CD28- T cells in immune disorders

Aging of the immune system contributes to the increased morbidity and mortality of the elderly population and may occur prematurely in patients with immune disorders. One of the main characteristics of immunosenescence is the expansion of CD4(+)CD28(-) T cells in the blood. These cells are effector memory T cells with cytotoxic capacity, and have been recently described to have pathogenic potential in a variety of immune disorders. Interestingly, CD4(+)CD28(-) T cells have now been found to infiltrate target tissues of patients with multiple sclerosis, rheumatoid arthritis, myopathies, acute coronary syndromes, and other immune-related diseases. In this review, we discuss potential factors and mechanisms that may induce the expansion of these cells, as well as their putative pathogenic mechanisms in immune disorders.