[Influence of underlying disease and immunosuppression on the immunocompetence in inflammatory rheumatic diseases]

Patients with inflammatory rheumatic diseases have a higher risk of infections in comparison to the general population. For this patient group, in addition to cardiovascular diseases, infections play an important role with respect to morbidity and mortality. Even if it is difficult to make concrete statements with respect to individual diseases, it can be assumed that there is a lower risk of infections in inflammatory joint diseases in comparison to connective tissue diseases and vasculitides. The increased risk of infections is determined by multiple factors, whereby the underlying factors are classified into three main categories: patient-related factors (age, comorbidities, lifestyle), disease-related factors (immunological dysfunction as part of the disease pathophysiology) and drug-related factors (type and dosage of the immunosuppression and/or immunomodulation). An improved understanding of the complexity of these associations enables the optimization of treatment and disease control taking the individual risk factors into account, with the aim of a significant reduction in the risk of infections.

UNC93B1 variants underlie TLR7-dependent autoimmunity

UNC93B1 is critical for trafficking and function of nucleic acid-sensing Toll-like receptors (TLRs) TLR3, TLR7, TLR8, and TLR9, which are essential for antiviral immunity. Overactive TLR7 signaling induced by recognition of self-nucleic acids has been implicated in systemic lupus erythematosus (SLE). Here, we report UNC93B1 variants (E92G and R336L) in four patients with early-onset SLE. Patient cells or mouse macrophages carrying the UNC93B1 variants produced high amounts of TNF-α and IL-6 and upon stimulation with TLR7/TLR8 agonist, but not with TLR3 or TLR9 agonists. E92G causes UNC93B1 protein instability and reduced interaction with TLR7, leading to selective TLR7 hyperactivation with constitutive type I IFN signaling. Thus, UNC93B1 regulates TLR subtype-specific mechanisms of ligand recognition. Our findings establish a pivotal role for UNC93B1 in TLR7-dependent autoimmunity and highlight the therapeutic potential of targeting TLR7 in SLE.

Efficacy and safety of remibrutinib, a selective potent oral BTK inhibitor, in Sjögren's syndrome: results from a randomised, double-blind, placebo-controlled phase 2 trial

OBJECTIVES

To evaluate the safety and efficacy of remibrutinib in patients with moderate-to-severe Sjögren's syndrome (SjS) in a phase 2 randomised, double-blind trial (NCT04035668; LOUiSSE (LOU064 in Sjögren's Syndrome) study).

METHODS

Eligible patients fulfilling 2016 American College of Rheumatology/European League Against Rheumatism (EULAR) criteria for SjS, positive for anti-Ro/Sjögren's syndrome-related antigen A antibodies, with moderate-to-severe disease activity (EULAR Sjögren's Syndrome Disease Activity Index (ESSDAI) (based on weighted score) ≥ 5, EULAR Sjögren's Syndrome Patient Reported Index (ESSPRI) ≥ 5) received remibrutinib (100 mg) either one or two times a day, or placebo for the 24-week study treatment period. The primary endpoint was change from baseline in ESSDAI at week 24. Key secondary endpoints included change from baseline in ESSDAI over time, change from baseline in ESSPRI over time and safety of remibrutinib in SjS. Key exploratory endpoints included changes to the salivary flow rate, soluble biomarkers, blood transcriptomic and serum proteomic profiles.

RESULTS

Remibrutinib significantly improved ESSDAI score in patients with SjS over 24 weeks compared with placebo (ΔESSDAI -2.86, p=0.003). No treatment effect was observed in ESSPRI score (ΔESSPRI 0.17, p=0.663). There was a trend towards improvement of unstimulated salivary flow with remibrutinib compared with placebo over 24 weeks. Remibrutinib had a favourable safety profile in patients with SjS over 24 weeks. Remibrutinib induced significant changes in gene expression in blood, and serum protein abundance compared with placebo.

CONCLUSIONS

These data show preliminary efficacy and favourable safety of remibrutinib in a phase 2 trial for SjS.

EULAR recommendations for the management of systemic lupus erythematosus: 2023 update

OBJECTIVES

To update the EULAR recommendations for the management of systemic lupus erythematosus (SLE) based on emerging new evidence.

METHODS

An international Task Force formed the questions for the systematic literature reviews (January 2018-December 2022), followed by formulation and finalisation of the statements after a series of meetings. A predefined voting process was applied to each overarching principle and recommendation. Levels of evidence and strengths of recommendation were assigned, and participants finally provided their level of agreement with each item.

RESULTS

The Task Force agreed on 5 overarching principles and 13 recommendations, concerning the use of hydroxychloroquine (HCQ), glucocorticoids (GC), immunosuppressive drugs (ISDs) (including methotrexate, mycophenolate, azathioprine, cyclophosphamide (CYC)), calcineurin inhibitors (CNIs, cyclosporine, tacrolimus, voclosporin) and biologics (belimumab, anifrolumab, rituximab). Advice is also provided on treatment strategies and targets of therapy, assessment of response, combination and sequential therapies, and tapering of therapy. HCQ is recommended for all patients with lupus at a target dose 5 mg/kg real body weight/day, considering the individual's risk for flares and retinal toxicity. GC are used as 'bridging therapy' during periods of disease activity; for maintenance treatment, they should be minimised to equal or less than 5 mg/day (prednisone equivalent) and, when possible, withdrawn. Prompt initiation of ISDs (methotrexate, azathioprine, mycophenolate) and/or biological agents (anifrolumab, belimumab) should be considered to control the disease and facilitate GC tapering/discontinuation. CYC and rituximab should be considered in organ-threatening and refractory disease, respectively. For active lupus nephritis, GC, mycophenolate or low-dose intravenous CYC are recommended as anchor drugs, and add-on therapy with belimumab or CNIs (voclosporin or tacrolimus) should be considered. Updated specific recommendations are also provided for cutaneous, neuropsychiatric and haematological disease, SLE-associated antiphospholipid syndrome, kidney protection, as well as preventative measures for infections, osteoporosis, cardiovascular disease.

CONCLUSION

The updated recommendations provide consensus guidance on the management of SLE, combining evidence and expert opinion.

Cellular Immunobiology and Molecular Mechanisms in Alloimmunity-Pathways of Immunosuppression

Current maintenance immunosuppression commonly comprises a synergistic combination of tacrolimus as calcineurin inhibitor (CNI), mycophenolic acid, and glucocorticoids. Therapy is often individualized by steroid withdrawal or addition of belatacept or inhibitors of the mechanistic target of rapamycin. This review provides a comprehensive overview of their mode of action, focusing on the cellular immune system. The main pharmacological action of CNIs is suppression of the interleukin-2 pathway that leads to inhibition of T cell activation. Mycophenolic acid inhibits the purine pathway and subsequently diminishes T and B cell proliferation but also exerts a variety of effects on almost all immune cells, including inhibition of plasma cell activity. Glucocorticoids exert complex regulation via genomic and nongenomic mechanisms, acting mainly by downregulating proinflammatory cytokine signatures and cell signaling. Belatacept is potent in inhibiting B/T cell interaction, preventing formation of antibodies; however, it lacks the potency of CNIs in preventing T cell-mediated rejections. Mechanistic target of rapamycin inhibitors have strong antiproliferative activity on all cell types interfering with multiple metabolic pathways, partly explaining poor tolerability, whereas their superior effector T cell function might explain their benefits in the case of viral infections. Over the past decades, clinical and experimental studies provided a good overview on the underlying mechanisms of immunosuppressants. However, more data are needed to delineate the interaction between innate and adaptive immunity to better achieve tolerance and control of rejection. A better and more comprehensive understanding of the mechanistic reasons for failure of immunosuppressants, including individual risk/benefit assessments, may permit improved patient stratification.

2023 International Consensus Guidance for the use of Tripterygium Wilfordii Hook F in the treatment of active rheumatoid arthritis

BACKGROUND

Rheumatoid arthritis (RA) is a chronic autoimmune disorder that affects the joints and produces pain, swelling, and stiffness. It has a lifetime prevalence of up to 1% worldwide. An extract of Tripterygium wilfordii Hook F (TwHF), a member of the Celastraceae herbal family widely available in south China, has been used for treatment of RA since 1960s.

METHODS

The current consensus practice guidance (CPG) aims to offer guidance on the application of TwHF in the clinical management of active RA. The CPG followed World Health Organisation (WHO)'s recommended process, carried out three systematic reviews to synthesize data from 19 randomised controlled trials (RCT) involving 1795 participants. We utilized Grading of Recommendations, Assessment, Development and Evaluation (GRADE) to evaluate certainty of evidence and derive recommendations. We rigorously followed The Appraisal of Guidelines for Research and Evaluation II (AGREE II) as conduct guides to minimise bias and promote transparency.

RESULTS

There was no obvious difference between TwHF monotherapy and methotrexate (MTX) monotherapy on ACR20 (RCT = 2, N = 390, RR = 1.06, 95%CI 0.90-1.26, moderate certainty), ACR50 (RCT = 3, N = 419, RR = 1.03, 95%CI 0.80-1.34, moderate certainty), ACR70 (RCT = 2, N = 390, RR = 1.12, 95%CI 0.69-1.79, low certainty). TwHF monotherapy may be better than salicylazosulfapyridine monotherapy on ACR20 and the effect may be similar on ACR50 and ACR70. Seven RCTs compared MTX combined with TwHF versus MTX monotherapy, and the meta-analysis results favoured combination therapy group on ACR20 (RCT = 3, N = 470, RR = 1.44, 95%CI 1.28-1.62, moderate certainty), ACR50 (RCT = 4, N = 500, RR = 1.88, 95%CI 1.56-2.28, moderate certainty) and ACR70 (RCT = 2, N = 390, RR = 2.12, 95%CI 1.40-3.19, low certainty). We found no obvious difference between groups on critical safety outcomes, including infection (RCT = 3, N = 493, RR = 1.37, 95%CI 0.84-2.23), liver dysfunction (RCT = 5, N = 643, RR = 1.14, 95%CI 0.71-1.85), renal damage (RCT = 3, N = 450, RR = 2.20, 95%CI 0.50-9.72).

CONCLUSION

Upon full review of the evidence, the guidance panel reached consensus on recommendations for the use of TwHF in people with active RA, either as monotherapy or as combination therapy with MTX.

Transcriptional profiling upon T cell stimulation reveals down-regulation of inflammatory pathways in T and B cells in SLE versus Sjögren's syndrome

Systemic lupus erythematosus (SLE) and primary Sjögren's syndrome (pSS) share clinical as well as pathogenic similarities. Although previous studies suggest various abnormalities in different immune cell compartments, dedicated cell-type specific transcriptomic signatures are often masked by patient heterogeneity. Here, we performed transcriptional profiling of isolated CD4, CD8, CD16 and CD19 lymphocytes from pSS and SLE patients upon T cell stimulation, in addition to a steady-state condition directly after blood drawing, in total comprising 581 sequencing samples. T cell stimulation, which induced a pronounced inflammatory response in all four cell types, gave rise to substantial re-modulation of lymphocyte subsets in the two autoimmune diseases compared to healthy controls, far exceeding the transcriptomic differences detected at steady-state. In particular, we detected cell-type and disease-specific down-regulation of a range of pro-inflammatory cytokine and chemokine pathways. Such differences between SLE and pSS patients are instrumental for selective immune targeting by future therapies.

Cross-regulation of antibody responses against the SARS-CoV-2 Spike protein and commensal microbiota via molecular mimicry

The commensal microflora provides a repertoire of antigens that illicit mucosal antibodies. In some cases, these antibodies can cross-react with host proteins, inducing autoimmunity, or with other microbial antigens. We demonstrate that the oral microbiota can induce salivary anti-SARS-CoV-2 Spike IgG antibodies via molecular mimicry. Anti-Spike IgG antibodies in the saliva correlated with enhanced abundance of Streptococcus salivarius 1 month after anti-SARS-CoV-2 vaccination. Several human commensal bacteria, including S. salivarius, were recognized by SARS-CoV-2-neutralizing monoclonal antibodies and induced cross-reactive anti-Spike antibodies in mice, facilitating SARS-CoV-2 clearance. A specific S. salivarius protein, RSSL-01370, contains regions with homology to the Spike receptor-binding domain, and immunization of mice with RSSL-01370 elicited anti-Spike IgG antibodies in the serum. Additionally, oral S. salivarius supplementation enhanced salivary anti-Spike antibodies in vaccinated individuals. Altogether, these data show that distinct species of the human microbiota can express molecular mimics of SARS-CoV-2 Spike protein, potentially enhancing protective immunity.

Translational implications of newly characterized pathogenic pathways in systemic lupus erythematosus

Improved characterization of relevant pathogenic pathways in systemic lupus erythematosus (SLE) has been further delineated over the last decades. This led to the development of targeted treatments including belimumab and anifrolumab, which recently became available in clinics. Therapeutic targets in SLE encompass interferon (IFN) signaling, B-T costimulation including immune checkpoints, and increasing modalities of B lineage targeting, such as chimeric antigen receptor (CAR) T cells directed against CD19 or sequential anti-B cell targeting. Patient profiling based on characterization of underlying molecular abnormalities, often performed through comprehensive omics analyses, has recently been shown to better predict patients' treatment responses and also holds promise to unravel key molecular mechanisms driving SLE. SLE carries two key signatures, namely the IFN and B lineage/plasma cell signatures. Recent advances in SLE treatments clearly indicate that targeting innate and adaptive immunity is successful in such a complex autoimmune disease. Although those signatures may interact at the molecular level and provide the basis for the first selective treatments in SLE, it remains to be clarified whether these distinct treatments show different treatment responses among certain patient subsets. In fact, notwithstanding the remarkable amount of novel clues for innovative SLE treatment, harmonization of big data within tailored treatment strategies will be instrumental to better understand and treat this challenging autoimmune disorder. This review will provide an overview of recent improvements in SLE pathogenesis, related insights by analyses of big data and machine learning as well as technical improvements in conducting clinical trials with the ultimate goal that translational research results in improved patient outcomes.

Safety profile of baricitinib in patients with systemic lupus erythematosus: an integrated analysis

OBJECTIVES

To assess the safety of the oral Janus kinase inhibitor baricitinib in adult patients with systemic lupus erythematosus (SLE) receiving stable background therapy. Topics of special interest included infections and cardiovascular and thromboembolic events.

METHODS

This analysis included integrated safety data from three randomised, placebo-controlled studies (one phase 2 and two phase 3) and one long-term extension study. Data are reported in three data sets: placebo-controlled, extended exposure and all-baricitinib. Outcomes include treatment-emergent adverse events (AEs), AEs of special interest and abnormal laboratory changes. Proportions of patients with events and incidence rates (IRs) were calculated.

RESULTS

A total of 1655 patients received baricitinib for up to 3.5 years (median duration 473 days). With baricitinib 4 mg, baricitinib 2 mg and placebo, respectively, 50.8%, 50.7% and 49.0% of patients reported at least one infection and 4.4%, 3.4% and 1.9% of patients had a serious infection. The most common treatment-emergent infections included urinary tract infection, COVID-19, upper respiratory tract infection and nasopharyngitis. Herpes zoster was more common with baricitinib 4 mg (4.7%) vs baricitinib 2 mg (2.7%) and placebo (2.8%). Among baricitinib-4 mg, 2 mg and placebo-treated patients, respectively, 4 (IR=0.9), 1 (IR=0.2) and 0 experienced at least one positively adjudicated major adverse cardiovascular event, and 0, 3 (IR=0.6) and 2 (IR=0.4) reported at least one positively adjudicated venous thromboembolism.

CONCLUSIONS

The results of this integrated safety analysis in patients with SLE are not substantially different to the established safety profile of baricitinib. No increased venous thromboembolism was found.

Baricitinib for systemic lupus erythematosus: a double-blind, randomised, placebo-controlled, phase 3 trial (SLE-BRAVE-I)

BACKGROUND

Baricitinib is an oral selective inhibitor of Janus kinase 1 and 2 approved for the treatment of rheumatoid arthritis, atopic dermatitis, and alopecia areata. In a 24-week phase 2 study in patients with systemic lupus erythematosus (SLE), baricitinib 4 mg significantly improved SLE disease activity compared with placebo. The objective of this trial was to evaluate the efficacy and safety of baricitinib in patients with active SLE in a 52-week phase 3 study.

METHODS

In a multicentre, double-blind, randomised, placebo-controlled, parallel-group, phase 3 study, SLE-BRAVE-I, patients (aged ≥18 years) with active SLE receiving stable background therapy were randomly assigned 1:1:1 to baricitinib 4 mg, 2 mg, or placebo once daily for 52 weeks with standard of care. Glucocorticoid tapering was encouraged but not required per protocol. The primary endpoint was the proportion of patients reaching an SLE Responder Index (SRI)-4 response at week 52 in the baricitinib 4 mg treatment group compared with placebo. The primary endpoint was assessed by logistic regression analysis with baseline disease activity, baseline corticosteroid dose, region, and treatment group in the model. Efficacy analyses were done on a modified intention-to-treat population, comprising all participants who were randomly assigned and received at least one dose of investigational product. Safety analyses were done on all randomly assigned participants who received at least one dose of investigational product and who did not discontinue from the study for the reason of lost to follow-up at the first post-baseline visit. This study is registered with ClinicalTrials.gov, NCT03616912.

FINDINGS

760 participants were randomly assigned and received at least one dose of baricitinib 4 mg (n=252), baricitinib 2 mg (n=255), or placebo (n=253). A significantly greater proportion of participants who received baricitinib 4 mg (142 [57%]; odds ratio 1·57 [95% CI 1·09 to 2·27]; difference with placebo 10·8 [2·0 to 19·6]; p=0·016), but not baricitinib 2 mg (126 [50%]; 1·14 [0·79 to 1·65]; 3·9 [-4·9 to 12·6]; p=0·47), reached SRI-4 response compared with placebo (116 [46%]). There were no significant differences between the proportions of participants in either baricitinib group reaching any of the major secondary endpoints compared with placebo, including glucocorticoid tapering and time to first severe flare. 26 (10%) participants receiving baricitinib 4 mg had serious adverse events, 24 (9%) participants receiving baricitinib 2 mg, and 18 (7%) participants receiving placebo. The safety profile of baricitinib in participants with SLE was consistent with the known baricitinib safety profile.

INTERPRETATION

The primary endpoint in this study was met for the 4 mg baricitinib group. However, key secondary endpoints were not. No new safety signals were observed.

FUNDING

Eli Lilly and Company.

Baricitinib for systemic lupus erythematosus: a double-blind, randomised, placebo-controlled, phase 3 trial (SLE-BRAVE-II)

BACKGROUND

Baricitinib is an oral selective inhibitor of Janus kinase 1 and 2 approved for the treatment of rheumatoid arthritis, atopic dermatitis, and alopecia areata. In a 24-week phase 2 study in patients with systemic lupus erythematosus (SLE), baricitinib 4 mg significantly improved SLE disease activity compared with placebo. In this Article, we report the evaluation of efficacy and safety of baricitinib in patients with SLE in a 52-week phase 3 study.

METHODS

In this phase 3 double-blind, randomised, placebo-controlled study, SLE-BRAVE-II, patients (aged ≥18 years) with active SLE receiving stable background therapy were randomly assigned 1:1:1 to baricitinib 4 mg, baricitinib 2 mg, or placebo once daily for 52 weeks. The primary endpoint was the proportion of patients with an SLE Responder Index (SRI)-4 response at week 52 in the baricitinib 4 mg treatment group compared with placebo. Glucocorticoid tapering was encouraged but not required per protocol. The primary endpoint was assessed by logistic regression analysis with baseline disease activity, baseline corticosteroid dose, region, and treatment group in the model. Efficacy analyses were done on an intention-to-treat population, comprising all participants who were randomly assigned and received at least one dose of investigational product and who did not discontinue from the study for the reason of lost to follow-up at the first post-baseline visit. Safety analyses were done on all randomly assigned participants who received at least one dose of investigational product and who did not discontinue. This study is registered with ClinicalTrials.gov, NCT03616964, and is complete.

FINDINGS

A total of 775 patients were randomly assigned and received at least one dose of baricitinib 4 mg (n=258), baricitinib 2 mg (n=261), or placebo (n=256). There was no difference in the primary efficacy outcome of the proportion of SRI-4 responders at week 52 between participants who received baricitinib 4mg (121 [47%]; odds ratio 1·07 [95% CI 0·75 to 1·53]; difference with placebo 1·5 [95% CI -7·1 to 10·2]), 2 mg (120 [46%]; 1·05 [0·73 to 1·50]; 0·8 [-7·9 to 9·4]) and placebo (116 [46%]). None of the major secondary endpoints, including glucocorticoid tapering and time to first severe flare, were met. Serious adverse events were observed in 29 (11%) participants in the baricitinib 4 mg group, 35 (13%) in the baricitinib 2 mg group, and 22 (9%) in the placebo group. The safety profile of baricitinib in patients with SLE was consistent with the known baricitinib safety profile.

INTERPRETATION

Although phase 2 data suggested baricitinib as a potential treatment for patients with SLE, which was supported in SLE-BRAVE-I, this result was not replicated in SLE-BRAVE-II. No new safety signals were observed.

FUNDING

Eli Lilly and Company.

[Practicable diagnostics of Sjögren's syndrome in interstitial lung disease-A discussion article]

Sjögren's syndrome (SjS) is a possible autoimmune cause of interstitial lung disease. The diagnostic pathway for SjS, however, is largely undefined in comparison to other systemic autoimmune diseases. Subjective sicca symptoms, anti-SS-A/Ro antibodies and even ANA as screening tests all have relevant limitations in sensitivity and/or specificity. Against this background, in an interdisciplinary discussion we have developed a consensus for the clarification of SjS, which is presented here for broader discussion. In addition to ANA and anti-SS-A/Ro antibodies, antibodies against alpha-fodrin should be included. Objective measures of dryness, such a Schirmer and Saxon tests are important, as is a salivary gland biopsy in the absence of typical autoantibodies.

Efficacy and Safety of the Bruton's Tyrosine Kinase Inhibitor Evobrutinib in Systemic Lupus Erythematosus: Results of a Phase II, Randomized, Double-Blind, Placebo-Controlled Dose-Ranging Trial

OBJECTIVE

Evobrutinib is a highly selective, orally administered Bruton's tyrosine kinase (BTK) inhibitor. The objective of this phase II, multicenter, randomized, double-blind, placebo-controlled trial was to evaluate the efficacy and safety of evobrutinib in patients with active autoantibody-positive systemic lupus erythematosus (SLE).

METHODS

Patients were diagnosed with SLE by either the Systemic Lupus International Collaborating Clinics criteria or at least four American College of Rheumatology criteria 6 months or more prior to screening, had an SLE Disease Activity Index-2000 score of 6 or more, were autoantibody-positive and on standard-of-care therapy. Randomization was 1:1:1:1 to oral evobrutinib 25 mg once daily (QD), 75 mg QD, 50 mg twice daily, or placebo. Primary efficacy endpoints were SLE responder index (SRI)-4 response at week 52 and SRI-6 response at week 52 in the high disease activity subpopulation. Safety endpoints included treatment-emergent adverse events (TEAEs).

RESULTS

A total of 469 patients were randomized and received at least one dose of evobrutinib or placebo at the time of primary analysis. Mean (SD) age at baseline was 40.7 (±12.3) years; 94.9% of patients were female. Neither primary efficacy endpoint was met. All doses of evobrutinib were well tolerated, and there was no clear dose effect on the incidence of reported TEAEs, or serious TEAEs, including severe infections.

CONCLUSION

This phase II, dose-ranging trial in SLE failed to show a treatment effect of evobrutinib versus placebo at any dose. Evobrutinib was generally well tolerated, with no dose effect observed for TEAEs. These results suggest that BTK inhibition does not appear to be an effective therapeutic intervention for patients with SLE.

Induction of cross-reactive, mucosal anti-SARS-CoV-2 antibody responses in rheumatoid arthritis patients after 3rd dose of COVID-19 vaccination

Systemic vaccination against SARS-CoV-2 elicited high titers of specific antibodies in the blood and in the oral cavity. Preexisting autoimmune diseases, such as rheumatoid arthritis, and biological treatments, like B cell depletion, are known to exhibit higher risk of severe COVID-19 manifestation and increased frequency of breakthrough infections after vaccination. We hypothesized that such increased risk is associated with an aberrant induction of secreted antibodies in the oral cavity. Here we evaluated the levels of secreted antibodies in the oral cavity against the SARS-CoV-2 Spike protein during the course of vaccination in RA patients with or without B cell depletion. We found that total salivary IgG levels were correlated with number of B cells in the blood. Anti-Spike IgG responses 7 days after second vaccination were induced in the oral cavity of all healthy individuals, while only 6 out 23 RA patients exhibited anti-Spike IgG in their saliva regardless of B cell depleting therapy. Importantly, both salivary and serologic anti-Spike IgG and IgA responses towards WT and omicron Spike variants were efficiently induced by third vaccination in RA patients with or without B cell depletion to the levels that were similar to healthy individuals. Altogether, these data advocate for the necessity of three dose vaccination for RA patients to mount anti-Spike antibody responses at the mucosal surfaces and annotate the reduction of secreted salivary IgG by B cell depletion.

Towards the identification of novel autoantibodies in Sjögren's syndrome

Primary Sjögren's syndrome may be difficult to diagnose when antibodies against Ro/SSA are lacking, and can be grouped in at least four clusters indicating different pathophysiological pathways. Novel biomarkers, in particular autoantibodies, would be helpful in diagnosing Sjögren's syndrome and in further identification and characterisation of the clusters.In this review, we describe new technologies that may be utilised in the rapid identification of novel autoantibodies, and an example of how well characterised patients, here from the HarmonicSS cohort, are a prerequisite in the discovery of clinically meaningful biomarkers. This translational approach hold promise to optimise the diagnosis and treatment of individual pSS patient subsets.

Editorial

Gemeinsam mit allen Autoren des vorliegenden Heftes, freuen wir uns, Ihnen aktuelle Aspekte zu Veränderungen im Bereich der Gerinnung bei entzündlich rheumatischen Erkrankungen vorzustellen. Die Komplexität im Bereich der Rheumatologie beinhaltet unterschiedliche Aktivierungszustände des Immunsystems, welche über humorale und zelluläre Mechanismen im Rahmen der Körperabwehr auch mit Gerinnungsaktivierung einhergehen können. Gut bekannt sind die Arthropathie bei Hämophiliepatienten, bei denen die sog. „Annual Bleeding Rates“ in Gelenke durch adäquate Faktorensubstution und schließlich den Möglichkeiten der Gentherapien revolutionär erniedrigt wurden.

Efficient CRISPR-Cas9-mediated mutagenesis in primary human B cells for identifying plasma cell regulators

Human B lymphocytes are attractive targets for immunotherapies in autoantibody-mediated diseases. Gene editing technologies could provide a powerful tool to determine gene regulatory networks regulating B cell differentiation into plasma cells, and identify novel therapeutic targets for prevention and treatment of autoimmune disorders. Here, we describe a new approach that uses CRISPR-Cas9 technology to target genes in primary human B cells in vitro for identifying plasma cell regulators. We found that sgRNA and Cas9 components can be efficiently delivered into primary human B cells through RD114-pseudotyped retroviral vectors. Using this system, we achieved approximately 80% of gene knockout efficiency. We disrupted expression of a triad of transcription factors, IRF4, PRDM1, and XBP1, and showed that human B cell survival and plasma cell differentiation are severely impaired. Specifically, that IRF4, PRDM1, and XBP1 were expressed at different stages during plasma cell differentiation, IRF4, PRDM1, and XBP1-targeted B cells failed to progress to the pre-plasmablast, plasma cell state, and plasma cell survival, respectively. Our method opens a new avenue to study gene functions in primary human B cells and identify novel plasma cell regulators for therapeutic applications.

Thromboinflammation: Dynamik physiologischer und pathologischer Wechselwirkungen von Entzündung und Koagulation

Das konzertante Zusammenspiel zwischen endothelialer Dysfuntion, aktivierten Thrombozyten und anderen Immunzellen sowie simultaner Komplementaktivierung führt zur Aktivierung und gegenseitigen Verstärkung sowohl der Immunantwort als auch der Gerinnungskaskade. Durch die unkontrollierte Fortdauer dieser physiologischen Mechanismen kann der pathologische Prozess der Thromboinflammation induziert werden. In dieser Übersichtsarbeit fassen wir grundlegende Mechanismen zusammen, die zur Thromboinflammation als ein Auslöser von venösen Thromboembolien führen.

Current and future treatment in primary Sjögren's syndrome - A still challenging development

Primary Sjögren's syndrome (pSS) is a chronic autoimmune disease characterized by sicca symptoms, systemic manifestations and constitutional symptoms substantially diminishing patient's quality of life. In this review, we summarize recent recommendations for management of pSS patients and current clinical studies in pSS addressing unmet medical needs. Expanding knowledge about disease pathogenesis and the introduction of validated outcome measures, such as capturing disease activity (ESSDAI) and patient-reported outcomes (ESSPRI) have shaped recent developments. In contrast, lack of evidence for current treatment options remarkably limits the management of pSS patients as reflected by the 2019 updated EULAR recommendations for management of Sjögren's syndrome. In this context, symptomatic treatment is usually appropriate for sicca symptoms, whereas systemic treatment is reserved for moderate to severe organ manifestations including care by a multidisciplinary team in centers of expertise. Most promising targets for new treatment modalities are based on immunopathological insights and include direct B cell targeting strategies, targeting co-stimulation by CD40/CD40L blocking, inhibition of key cytokine activity (BLyS/BAFF, type I interferon) and intracellular signaling pathways.

Cytokine levels associated with favorable clinical outcome in the CAPSID randomized trial of convalescent plasma in patients with severe COVID-19

Objectives

To determine the profile of cytokines in patients with severe COVID-19 who were enrolled in a trial of COVID-19 convalescent plasma (CCP).

Methods

Patients were randomized to receive standard treatment and 3 CCP units or standard treatment alone (CAPSID trial, ClinicalTrials.gov NCT04433910). The primary outcome was a dichotomous composite outcome (survival and no longer severe COVID-19 on day 21). Time to clinical improvement was a key secondary endpoint. The concentrations of 27 cytokines were measured (baseline, day 7). We analyzed the change and the correlation between serum cytokine levels over time in different subgroups and the prediction of outcome in receiver operating characteristics (ROC) analyses and in multivariate models.

Results

The majority of cytokines showed significant changes from baseline to day 7. Some were strongly correlated amongst each other (at baseline the cluster IL-1ß, IL-2, IL-6, IL-8, G-CSF, MIP-1α, the cluster PDGF-BB, RANTES or the cluster IL-4, IL-17, Eotaxin, bFGF, TNF-α). The correlation matrix substantially changed from baseline to day 7. The heatmaps of the absolute values of the correlation matrix indicated an association of CCP treatment and clinical outcome with the cytokine pattern. Low levels of IP-10, IFN-γ, MCP-1 and IL-1ß on day 0 were predictive of treatment success in a ROC analysis. In multivariate models, low levels of IL-1ß, IFN-γ and MCP-1 on day 0 were significantly associated with both treatment success and shorter time to clinical improvement. Low levels of IP-10, IL-1RA, IL-6, MCP-1 and IFN-γ on day 7 and high levels of IL-9, PDGF and RANTES on day 7 were predictive of treatment success in ROC analyses. Low levels of IP-10, MCP-1 and high levels of RANTES, on day 7 were associated with both treatment success and shorter time to clinical improvement in multivariate models.

Conclusion

This analysis demonstrates a considerable dynamic of cytokines over time, which is influenced by both treatment and clinical course of COVID-19. Levels of IL-1ß and MCP-1 at baseline and MCP-1, IP-10 and RANTES on day 7 were associated with a favorable outcome across several endpoints. These cytokines should be included in future trials for further evaluation as predictive factors.

Persistent but atypical germinal center reaction among 3rd SARS-CoV-2 vaccination after rituximab exposure

Background

Durable vaccine-mediated immunity relies on the generation of long-lived plasma cells and memory B cells (MBCs), differentiating upon germinal center (GC) reactions. SARS-CoV-2 mRNA vaccination induces a strong GC response in healthy volunteers (HC), but limited data is available about response longevity upon rituximab treatment.

Methods

We evaluated humoral and cellular responses upon 3rd vaccination in seven patients with rheumatoid arthritis (RA) who initially mounted anti-spike SARS-CoV-2 IgG antibodies after primary 2x vaccination and got re-exposed to rituximab (RTX) 1-2 months after the second vaccination. Ten patients with RA on other therapies and ten HC represented the control groups. As control for known long-lived induced immunity, we analyzed humoral and cellular tetanus toxoid (TT) immune responses in steady-state.

Results

After 3^rd vaccination, 5/7 seroconverted RTX patients revealed lower anti-SARS-CoV-2 IgG levels but similar neutralizing capacity compared with HC. Antibody levels after 3rd vaccination correlated with values after 2nd vaccination. Despite significant reduction of circulating total and antigen-specific B cells in RTX re-exposed patients, we observed the induction of IgG+ MBCs upon 3^rd vaccination. Notably, only RTX treated patients revealed a high amount of IgA+ MBCs before and IgA+ plasmablasts after 3^rd vaccination. IgA+ B cells were not part of the steady state TT+ B cell pool. TNF-secretion and generation of effector memory CD4 spike-specific T cells were significantly boosted upon 3^rd vaccination.

Summary

On the basis of pre-existing affinity matured MBCs within primary immunisation, RTX re-exposed patients revealed a persistent but atypical GC immune response accompanied by boosted spike-specific memory CD4 T cells upon SARS-CoV-2 recall vaccination.

Three-Month Follow-Up of Heterologous vs. Homologous Third SARS-CoV-2 Vaccination in Kidney Transplant Recipients: Secondary Analysis of a Randomized Controlled Trial

Response to SARS-CoV-2-vaccines in kidney-transplant recipients (KTR) is severely reduced. Heterologous3^rd vaccination combining mRNA and vector vaccines did not increase seroconversion at 4 weeks after vaccination, but evolution of antibody levels beyond the first month remains unknown. We have recently completed a randomized-controlled trial on heterologous (Ad26COVS1) vs. homologous (BNT162b2 or mRNA-1273) 3^rd vaccination in 201 KTR not developing SARS-CoV-2-spike-protein antibodies following two doses of mRNA vaccine (EurdraCT: 2021-002927-39). Here, we report seroconversion at the second follow-up at 3 months after the 3^rd vaccination (prespecified secondary endpoint). In addition, higher cut-off levels associated with neutralizing capacity and protective immunity were applied (i.e., > 15, > 100, > 141, and > 264 BAU/ml). A total of 169 patients were available for the 3-month follow-up. Overall, seroconversion at 3 months was similar between both groups (45 vs. 50% for mRNA and the vector group, respectively; p = 0.539). However, when applying higher cut-off levels, a significantly larger number of individuals in the vector group reached antibody levels > 141 and > 264 BAU/ml at the 3-month follow-up (141 BAU/ml: 4 vs. 15%, p = 0.009 and 264 BAU/ml: 1 vs. 10%, p = 0.018 for mRNA vs. the vector vaccine group, respectively). In line, antibody levels in seroconverted patients further increased from month 1 to month 3 in the vector group while remaining unchanged in the mRNA group (median increase: mRNA = 1.35 U/ml and vector = 27.6 U/ml, p = 0.004). Despite a similar overall seroconversion rate at 3 months following 3^rd vaccination in KTR, a heterologous 3rd booster vaccination with Ad26COVS1 resulted in significantly higher antibody levels in responders.

Aktuelle Aspekte und Strategien zum Einsatz oraler Antikoagulantien und Plättchenfunktionshemmer in der Praxis

Aufgrund erhöhter venöser und arterieller Risiken und Begleiterkrankungen bei entzündlich-rheumatischen Erkrankungen sind die Grundprinzipien der adäquaten medikamentösen Behandlung auch von Bedeutung in der rheumatologischen Praxis. Bei der oralen Antikoagulation haben die innovativen Nicht-Vitamin K-abhängigen oralen Antikoagulanzien (NOAK) die „klassischen“ Antikoagulanzien, die Vitamin K-Antagonisten (VKA), in vielen Indikationen weitgehend verdrängt; allerdings finden sich weiterhin Gründe, Patienten anstelle von NOAK mit VKA zu antikoagulieren. Bei der medikamentösen Hemmung der Plättchenfunktion werden neben ASS die Thienopyridine Clopidogrel und Prasugrel sowie Ticagrelor eingesetzt; von besonderer Bedeutung ist eine duale Plättchenfunktionshemmung (DAPT) mit Kombination verschiedener Plättchenhemmer. In dieser Übersichtsarbeit wird auf wichtige Aspekte der oralen Antikoagulation und der oralen Plättchenfunktionshemmung eingegangen.

Phase 3, multicentre, randomised, placebo-controlled study evaluating the efficacy and safety of ustekinumab in patients with systemic lupus erythematosus

OBJECTIVE

Evaluate the efficacy and safety of ustekinumab, an anti-interleukin-12/23 p40 antibody, in a phase 3, randomised, placebo-controlled study of patients with active systemic lupus erythematosus (SLE) despite receiving standard-of-care.

METHODS

Active SLE patients (SLE Disease Activity Index 2000 (SLEDAI-2K) ≥6 during screening and SLEDAI-2K ≥4 for clinical features at week 0) despite receiving oral glucocorticoids, antimalarials, or immunomodulatory drugs were randomised (3:2) to receive ustekinumab (intravenous infusion ~6 mg/kg at week 0, followed by subcutaneous injections of ustekinumab 90 mg at week 8 and every 8 weeks) or placebo through week 48. The primary endpoint was SLE Responder Index (SRI)-4 at week 52, and major secondary endpoints included time to flare through week 52 and SRI-4 at week 24.

RESULTS

At baseline, 516 patients were randomised to placebo (n=208) or ustekinumab (n=308). Following the planned interim analysis, the sponsor discontinued the study due to lack of efficacy but no safety concerns. Efficacy analyses included 289 patients (placebo, n=116; ustekinumab, n=173) who completed or would have had a week 52 visit at study discontinuation. At week 52, 44% of ustekinumab patients and 56% of placebo patients had an SRI-4 response; there were no appreciable differences between the treatment groups in the major secondary endpoints. Through week 52, 28% of ustekinumab patients and 32% of placebo patients had a British Isles Lupus Assessment Group flare, with a mean time to first flare of 204.7 and 200.4 days, respectively. Through week 52, 70% of ustekinumab patients and 74% of placebo patients had ≥1 adverse event.

CONCLUSIONS

Ustekinumab did not demonstrate superiority over placebo in this population of adults with active SLE; adverse events were consistent with the known safety profile of ustekinumab.

TRIAL REGISTRATION NUMBER

NCT03517722.

Advances in SLE classification criteria

This year, the American College of Rheumatology (ACR) 1982 classification criteria for systemic lupus erythematosus (SLE) celebrate their 40th anniversary. From this start, the quest for optimal SLE criteria has led to the 1997 ACR update, the 2012 publication of the Systemic Lupus International Collaborating Clinics (SLICC) criteria, and, in 2019, the European League Against Rheumatism (EULAR)/ACR classification criteria. The latter have since been externally validated in more than two dozen studies and have become the gold standard inclusion criterion of SLE clinical trials. This comprehensive review attempts to follow the evolving success story of SLE classification, highlighting relevant decisions and their rationale, and discussing consequences for the way SLE is defined and managed.

POS0714 POOLED SAFETY ANALYSIS OF BARICITINIB IN PATIENTS WITH SYSTEMIC LUPUS ERYTHEMATOSUS: RESULTS FROM THREE RANDOMISED, DOUBLE-BLIND, PLACEBO-CONTROLLED, CLINICAL TRIALS

Background

Baricitinib (BARI), an oral selective inhibitor of Janus kinase 1 and 2 approved for the treatment of rheumatoid arthritis and atopic dermatitis, has been evaluated in clinical studies in patients with systemic lupus erythematosus (SLE).

Objectives

To assess the safety profile of BARI in patients with SLE.

Methods

Patients with SLE receiving stable background therapy were randomised 1:1:1 to BARI 2-mg, 4-mg, or placebo (PBO) once daily in one 24-week, phase 2 (NCT02708095) and two 52-week, phase 3, PBO controlled studies (NCT03616912 and NCT03616964).

Results

A total of 1,849 patients were included in this pooled analysis, representing 1,463.5 patient years of exposure (PYE). The incidence rates per 100 PYR at risk (IR/100 PYR) for serious adverse events (SAEs) were 9.5, 14.7, and 14.1 respectively for PBO, BARI 2-mg, and BARI 4-mg. There were no clinically meaningful differences between treatment groups for discontinuations due to AEs or death (Table 1).

Table 1.

Overview of safety measures of baricitinib in patients with SLE

Safety measurePBOBARI 2-mgBARI 4-mgPooled-BARIN=614N=621N=614N=1235PYE=488.1PYE=494.0PYE=481.4PYE=975.4n(%)n(%)n(%)n(%)PYRPYRPYRPYR[IR; 95%CI][IR; 95%CI][IR; 95%CI][IR; 95%CI]SAEs45 (7.3)70 (11.3)*65 (10.6)*135 (10.9)*473.2476.6461.9938.5[9.5; 6.9, 12.7][14.7; 11.5, 18.6][14.1; 10.9, 17.9][14.4; 12.1, 17.0]Discontinuation of study drug due to AE48 (7.8)58 (9.3)57 (9.3)115 (9.3)485.3492.3480.6973.0[9.9; 7.3, 13.1][11.8; 8.9, 15.2][11.9; 9.0, 15.4][11.8; 9.8, 14.2]Death4 (0.7)1 (0.2)4 (0.7)5 (0.4)488.2494.0481.5975.5[0.8; 0.2, 2.1][0.2; 0.0, 1.1][0.8; 0.2, 2.1][0.5; 0.2, 1.2]Serious infections12 (2.0)22 (3.5)28 (4.6)*50 (4.0)*484.3487.2472.5959.7[2.5; 1.3, 4.3][4.5; 2.8, 6.8][5.9; 3.9, 8.6][5.2; 3.9, 6.9]Herpes Zoster18 (2.9)17 (2.7)29 (4.7)46 (3.7)481.1486.5468.6955.1[3.7; 2.2, 5.9][3.5; 2.0, 5.6][6.2; 4.1, 8.9][4.8; 3.5, 6.4]VTEs#6 (1.2)3 (0.6)1 (0.2)4 (0.4)444.0450.2438.1888.3[1.4; 0.5, 2.9][0.7; 0.1, 1.9][0.2; 0.0, 1.3][0.5; 0.1, 1.2]MACE#01 (0.2)3 (0.6)4 (0.4)443.9450.1438.1888.3[0.0; NA, 0.8][0.2; 0.0, 1.2][0.7; 0.1, 2.0][0.5; 0.1, 1.2]Malignancy excluding NMSC2 (0.3)3 (0.5)2 (0.3)5 (0.4)488.0494.1481.4975.5[0.4; 0.0, 1.5][0.6; 0.1, 1.8][0.4; 0.1, 1.5][0.5; 0.2, 1.2]NMSC2 (0.3)000*486.7494.0481.4975.4[0.4; 0.0, 1.5][0.0; NA, 0.7][0.0; NA, 0.8][0.0; NA, 0.4]

Data are n (%) patients PYR [IR; 95% CI]. #Phase 2 study data not included. AE=adverse event; CI=confidence interval; MACE=major adverse cardiac event; NMSC=non-melanoma skin cancers; VTE=venous thrombotic event (includes deep vein thrombosis and pulmonary embolism); IR=incidence rate (100 times the number of patients reporting an adverse event divided by the event-specific exposure to treatment); N=number of patients in the analysis population; n=number of patients in the specified category; PYE=patient-year of exposure; PYR=patient years at risk; SAE=serious adverse event. *p≤0.05 vs placebo.

The IR/100 PYR for serious infections were 2.5, 4.5, and 5.9 respectively for PBO, BARI 2-mg, and BARI 4-mg. The risk of Herpes Zoster was higher in BARI 4-mg (4.7%) vs PBO (2.9%) (Table 1).

The IR/100 PYR for positively adjudicated venous thrombotic events (VTEs) were 1.4, 0.7, and 0.2 respectively for PBO, BARI 2-mg, and BARI 4-mg. The IR/100 PYR for positively adjudicated major adverse cardiac event (MACE) was numerically higher in BARI 2-mg (0.2) and BARI 4-mg (0.7) vs PBO (0.0), however the pooled-BARI IR/PYR (0.5) was within the range of background disease (1). No increased risk for malignancies was observed.

Conclusion

The safety profile of BARI in SLE patients was consistent with the known BARI safety profile. There was no increased risk of VTE in BARI treatment groups.

References

[1]Barbhaiya M, Feldman CH, et al. Arthritis Rheumatol. 2017;69(9):1823-31.

Disclosure of Interests

Thomas Dörner Speakers bureau: Eli Lilly and Company and Roche, Consultant of: AbbVie, Celgene, Eli Lilly and Company, Janssen, Novartis, Roche, Samsung and UCB, Grant/research support from: Chugai, Janssen, Novartis and Sanofi, Yoshiya Tanaka Speakers bureau: Gilead, Abbvie, Behringer-Ingelheim, Eli Lilly, Mitsubishi-Tanabe, Chugai, Amgen, YL Biologics, Eisai, Astellas, Bristol-Myers, Astra-Zeneca, Consultant of: Eli Lilly, Daiichi-Sankyo, Taisho, Ayumi, Sanofi, GSK, Abbvie, Grant/research support from: Asahi-Kasei, Abbvie, Chugai, Mitsubishi-Tanabe, Eisai, Takeda, Corrona, Daiichi-Sankyo, Kowa, Behringer-Ingelheim, Marta Mosca Speakers bureau: Eli Lilly, GSK, Astra Zeneca, Consultant of: Eli Lilly, GSK, Astra Zeneca, Ian N. Bruce Speakers bureau: GSK, Astra Zeneca, UCB, Consultant of: Eli Lilly, GSK, UCB, BMS, Merck Serono, Astra Zeneca, IL-TOO, Aurinia, Grant/research support from: GSK, Janssen, Mario Cardiel Speakers bureau: Eli Lilly, Pfizer, Abbvie, Consultant of: Eli Lilly, Pfizer, Grant/research support from: Pfizer, Gilead, Roche, Janssen, Eric F. Morand Speakers bureau: AstraZeneca, Eli Lilly, Novartis, Consultant of: Amgen, AstraZeneca, Asahi Kasei, Biogen, BristolMyersSquibb, Capella, Eli Lilly, EMD Serono, Genentech, GlaxoSmithKline, Janssen, Neovacs, Sanofi, Servier, UCB, Wolf, Grant/research support from: Janssen, AstraZeneca, BristolMyersSquibb, Eli Lilly, EMD Serono, GlaxoSmithKline, Michelle A Petri Consultant of: Eli Lilly, Grant/research support from: Eli Lilly, Maria Silk Shareholder of: Eli Lilly, Employee of: Eli Lilly, christina dickson Shareholder of: Eli Lilly, Employee of: Eli Lilly, Gabriella Meszaros Shareholder of: Eli Lilly, Employee of: Eli Lilly, Maher Issa Shareholder of: Eli Lilly, Employee of: Eli Lilly, Lu Zhang Shareholder of: Eli Lilly, Employee of: Eli Lilly, Daniel J. Wallace Consultant of: Amgen, Eli Lilly and Company, EMD Merck Serono and Pfizer

POS0190 EFFICACY AND SAFETY OF BARICITINIB IN PATIENTS WITH SYSTEMIC LUPUS ERYTHEMATOSUS: RESULTS FROM TWO RANDOMISED, DOUBLE-BLIND, PLACEBO-CONTROLLED, PARALLEL-GROUP, PHASE 3 STUDIES

Background

In a 24-week, phase 2 clinical study (NCT02708095) in patients with systemic lupus erythematosus (SLE), baricitinib (BARI), an oral selective inhibitor of Janus kinase 1 and 2 approved for the treatment of rheumatoid arthritis and atopic dermatitis, inhibited the type l interferon gene signature, multiple other cytokine pathways, and improved disease activity (1) (2).

Objectives

To further evaluate the efficacy and safety of BARI in patients with SLE.

Methods

Patients with active SLE receiving stable background therapy were randomised 1:1:1 to BARI 2-mg, 4-mg, or placebo (PBO) once daily in two identically designed, 52-week, phase 3 randomised, PBO-controlled studies. In SLE-BRAVE-I (NCT03616912) and -II (NCT03616964), 760 and 775 patients, respectively were enrolled in a balanced manner across regions, although different countries per region participated in each study. The primary endpoint for both studies was the proportion of patients achieving an SLE Responder Index-4 (SRI-4) response at week 52. Glucocorticoid tapering was encouraged but not required per protocol.

Results

The mean Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K) at baseline was 10.1 for both SLE-BRAVE-I and -II participants; musculoskeletal and mucocutaneous domains were the most common domains involved at baseline. In SLE-BRAVE-I, the proportion of SRI-4 responders at week 52 among patients treated with BARI 4-mg (56.7%), but not BARI 2-mg (49.8%), was significantly greater than in patients treated with PBO (45.9%, p = 0.016) (Table 1). No difference was seen in SLE-BRAVE-II (47.1%, 46.3%, and 45.6%, BARI 4-mg, 2-mg, and PBO, respectively). None of the key secondary endpoints, including glucocorticoid tapering or time to first severe flare (SFI), were met in either study. The proportions of patients with serious adverse events (SAEs) were 7.1% and 8.6% for PBO, 9.4% and 13.4% for BARI 2-mg and 10.3% and 11.2% for BARI 4-mg in SLE-BRAVE-I and II, respectively.

Table 1.

Efficacy and safety of baricitinib in patients with SLE-BRAVE-I and -II

SLE-BRAVE-ISLE-BRAVE-IIEfficacy measurePBO (N=253)BARI 2-mg (N=255)BARI 4-mg (N=252)PBO (N=256)BARI 2-mg (N=261)BARI 4-mg (N=258)SRI-4 (W52)116 (45.9)126 (49.8)142 (56.7)*116 (45.6)120 (46.3)121 (47.1)SRI-4 (W24)99 (39.1)114 (44.8)117 (46.5)98 (38.6)104 (40.0)108 (42.1)Severe Flares (n, events)38 (15.0)34 (13.3)26 (10.3)26 (10.2)29 (11.1)29 (11.2)HR for time to first severe flare (SFI) HR [CI]NA0.8 [0.52, 1.32]0.65 [0.40, 1.08]NA1.1 [0.65, 1.89]1.1 [0.67, 1.94]Glucocorticoid sparing36 (30.8)31 (29.2)36 (34.0)33 (31.7)34 (29.8)36 (34.3)LLDAS (W52)66 (26.2)65 (25.7)74 (29.7)59 (23.2)62 (24.0)65 (25.4)Safety measureTEAE210 (83.0)210 (82.4)208 (82.5)198 (77.3)199 (76.2)200 (77.5)SAE18 (7.1)24 (9.4)26 (10.3)22 (8.6)35 (13.4)29 (11.2)

Data are n (%) patients, unless otherwise indicated. BARI=baricitinib; CI=confidence interval; HR=hazard ratio compared with PBO; LLDAS=lupus low disease activity state; N=number of patients in the analysis population; n=number of patients in the specified category; PBO=placebo; TEAE=treatment-emergent adverse event; SAE=serious adverse event; W=week. *p≤0.05 vs PBO.

Conclusion

Although phase 2 data suggested BARI as a potential treatment for patients with SLE (2), the SLE-BRAVE-I and -II phase 3 study results were discordant for the primary outcome measure, with only SLE-BRAVE-I positive, making it difficult to elucidate benefit. Additional analyses are being performed to understand this discordance. No new safety signals were observed.

References

[1]Dörner T, Tanaka Y, et al. Lupus Sci Med. 2020;7(1).

[2]Wallace DJ, Furie RA, et al. Lancet. 2018;392(10143):222-31.

Disclosure of Interests

Eric F. Morand Speakers bureau: Astra Zeneca, Eli Lilly, Novartis, Sanofi, Consultant of: Amgen, AstraZeneca, Asahi Kasei, Biogen, BristolMyersSquibb, Capella, Eli Lilly, EMD Serono, Genentech, Glaxosmithkline, Janssen, Neovacs, Sanofi, Servier, UCB, Wolf, Grant/research support from: Janssen, AstraZeneca, BristolMyersSquibb, Eli Lilly, EMD Serono, GlaxoSmithKline, Yoshiya Tanaka Speakers bureau: Gilead, Abbvie, Behringer-Ingelheim, Eli Lilly, Mitsubishi-Tanabe, Chugai, Amgen, YL Biologics, Eisai, Astellas, Bristol-Myers, Astra-Zeneca, Consultant of: Eli Lilly, Daiichi-Sankyo, Taisho, Ayumi, Sanofi, GSK, Abbvie, Grant/research support from: Asahi-Kasei, Abbvie, Chugai, Mitsubishi-Tanabe, Eisai, Takeda, Corrona, Daiichi-Sankyo, Kowa, Behringer-Ingelheim, Richard Furie Consultant of: Eli Lilly, Edward Vital Consultant of: Eli Lilly (consultant and honoraria), Ronald van Vollenhoven Consultant of: Abbvie, Biotest, BMS, Celgene, Crescendo, Eli Lilly and Company, GSK, Janssen, Merck, Novartis, Pfizer, Roche, UCB, Vertex, Grant/research support from: Abbvie, Amgen, BMS, GSK, Pfizer, Roche, UCB, Kenneth Kalunian Consultant of: Eli Lilly, Marta Mosca Consultant of: Eli Lilly, GSK, Astra Zeneca, Thomas Dörner Speakers bureau: AbbVie, Eli Lilly, BMS, Novartis, BMS/Celgene, Janssen, Consultant of: AbbVie, Eli Lilly, BMS, Novartis, BMS/Celgene, Janssen, Daniel J. Wallace Consultant of: Amgen, Eli Lilly and Company, EMD Merck Serono, and Pfizer, Maria Silk Shareholder of: Eli Lilly, Employee of: Eli Lilly, christina dickson Shareholder of: Eli Lilly, Employee of: Eli Lilly, Inmaculada De La Torre Shareholder of: Eli Lilly, Employee of: Eli Lilly, Gabriella Meszaros Shareholder of: Eli Lilly, Employee of: Eli Lilly, Bochao Jia Shareholder of: Eli Lilly, Employee of: Eli Lilly, Brenda Crowe Shareholder of: Eli Lilly, Employee of: Eli Lilly, Michelle A Petri Consultant of: Eli Lilly

POS0452 ABNORMALITY OF TYPE I INTERFERON SIGNALLING IN B CELLS IN PRIMARY SJÖGREN´S SYNDROME AND THE IMPACT ON LABORATORY AND CLINICAL FINDINGS

Background

B cell hyperactivity (1), autoantibody production (anti-SS-A, anti-SS-B) and hypergammaglobulinaemia as well as interferon (IFN) signature (2) play a central role in the pathogenesis of primary Sjögren´s Syndrome (pSS). The link between these hallmarks is still elusive. While treatment of pSS remains limited, an improved understanding of IFN and JAK/STAT signalling on B cells may hold promise to improve potential treatment targets and related biomarkers.

Objectives

To investigate downstream molecules of the IFN signalling pathway on B cells and their clinical impact in pSS.

Methods

Peripheral blood from 47 pSS patients and 36 matched healthy controls (HC) was obtained and permeabilized for intracellular staining. Here B and T cell markers were applied together with Signal Transducers and Activators of Transcription 1 (STAT1), STAT2, pSTAT1 and 2, Interferon Regulatory factor 9 (IRF9), IRF7 and IRF1 and analysed by using flow cytometry. Cell subsets and correlations with all markers and clinical information were subjected to statistical analyses.

Results

Compared to HC the pSS group showed significantly elevated STAT1 expression among all B cell subsets (p>0.0001) including naïve (CD27-IgD+), pre-switched (CD27+ IgD+), switched-memory (CD27+IgD-), double negative (CD27- IgD-) B cells and plasmablasts (CD27++ CD38++). Furthermore, IRF9 and STAT2 were increased among most B cell subsets.

Positive correlations were found between STAT1 and IRF9 with Siglec-1 (CD169), an IFN signature marker expressed on the surface of CD14+ monocytes (p>0.0001; r=0.633). Notably, increased levels of IRF9 positively correlates with STAT1.

Upregulated STAT1 and IRF9 within pSS B cells were associated to extraglandular manifestations, high anti-SS-A and anti-SS-B autoantibodies, high anti-nuclear antibody titers (ANA) and rheumatoid factors (IgA, IgM) in pSS patients.

Patients treated with prednisolone showed dose dependent inverse correlations of IRF9 expression among naïve-, memory-, and double negative B cells suggesting its treatment responsiveness.

Conclusion

The current data provide evidence of type I IFN on B cell subsets in pSS. Elevated STAT1, STAT2 and IRF9 expression suggest transcriptionally activity, which was evident in patients with extraglandular manifestations and elevated serologic activity.

Targeting JAK/STAT in pSS could be beneficial for patients with high STAT1 levels leading to a personalized approach for this specific subgroup of patients.

References

[1]Nocturne G, Mariette X. B cells in the pathogenesis of primary Sjögren syndrome. Nature Reviews Rheumatology. 2018;14(3):133-45.

[2]Brkic Z, Maria NI, Helden-Meeuwsen CGv, Merwe JPvd, Daele PLv, Dalm VA, et al. Prevalence of interferon type I signature in CD14 monocytes of patients with Sjögren’s syndrome and association with disease activity and BAFF gene expression. Annals of the Rheumatic Diseases. 2013;72(5):728-35.

Disclosure of Interests

None declared.

POS0050 B CELL CHARACTERISTICS AT BASELINE PREDICT HUMORAL RESPONSE UPON SARS-CoV-2 VACCINATION AMONG PATIENTS TREATED WITH RITUXIMAB

Background

Vaccination is considered efficient in controlling infections incl. SARS-CoV-2. Prior studies showed that patients receiving rituximab (RTX) with low B cell counts are at increased infectious risk (1) and risk of inadequate vaccination responses (2, 3). Thus, the ability to further define and predict vaccination responses in these patients may guide their optimal protection.

Objectives

To assess predictive biomarkers of vaccination responses upon SARS-CoV-2 vaccination in RTX treated patients.

Methods

B cell characteristics before vaccination were evaluated to predict responses in 15 patients with autoimmune inflammatory rheumatic diseases receiving RTX. 11 patients with rheumatoid arthritis on other therapies (RA), 11 kidney transplant recipients (KTR) and 15 healthy volunteers (HC) served as controls. A multidimensional analysis of B cell subsets and a correlation matrix were performed to identify predictive biomarkers.

Results

Significant differences regarding absolute B cell counts and specific subset distribution pattern between the groups were validated at baseline. Here, the majority of B cells from vaccination responders of the RTX group (RTX IgG+) comprised naïve and transitional B cells, whereas vaccination non-responders (RTX IgG-) carried preferentially plasmablasts and double negative (CD27-IgD-) B cells (Figure 1). Moreover, there was a positive correlation between neutralizing antibodies and absolute B cell numbers with B cells expressing HLA-DR and CXCR5 (involved in antigen presentation and germinal center formation) as well as an inverse correlation with CD95 expression and CD21low expression (marker for activation and exhaustion) on B cells.

Conclusion

Substantial repopulation of naïve B cells upon RTX therapy appears to be essential for an adequate vaccination response requiring germinal center formation. In contrast, expression of exhaustion markers (CD21low, CXCR5-, CD95+) indicate negative predictors of vaccination responses. These results may guide optimized vaccination strategies in RTX treated patients clearly requiring antigen-inexperienced B cells for appropriate protection.

References

[1]Sparks JA, Wallace ZS, Seet AM, Gianfrancesco MA, Izadi Z, Hyrich KL, et al. Associations of baseline use of biologic or targeted synthetic DMARDs with COVID-19 severity in rheumatoid arthritis: Results from the COVID-19 Global Rheumatology Alliance physician registry. Annals of the Rheumatic Diseases. 2021;80(9):1137-46.

[2]Stefanski AL, Rincon-Arevalo H, Schrezenmeier E, Karberg K, Szelinski F, Ritter J, et al. B cell numbers predict humoral and cellular response upon SARS-CoV-2 vaccination among patients treated with rituximab. Arthritis & Rheumatology. Accepted Author Manuscript.

[3]Mrak D, Tobudic S, Koblischke M, Graninger M, Radner H, Sieghart D, et al. SARS-CoV-2 vaccination in rituximab-treated patients: B cells promote humoral immune responses in the presence of T-cell-mediated immunity. Annals of the rheumatic diseases. 2021;80(10):1345-50.

Disclosure of Interests

None declared

Mechanism of action of baricitinib and identification of biomarkers and key immune pathways in patients with active systemic lupus erythematosus

OBJECTIVES

To elucidate the mechanism of action of baricitinib, a Janus kinase (JAK) 1/2 inhibitor, and describe immunological pathways related to disease activity in adults with systemic lupus erythematosus (SLE) receiving standard background therapy in a phase II trial.

METHODS

Patients with SLE were treated with baricitinib 2 mg or 4 mg in a phase II randomised, placebo-controlled study. Sera from 239 patients (baricitinib 2 mg: n=88; baricitinib 4 mg: n=82; placebo: n=69) and 49 healthy controls (HCs) were collected at baseline and week 12 and analysed using a proximity extension assay (Target 96 Inflammation Panel (Olink)). Interferon (IFN) scores were determined using an mRNA panel. Analytes were compared in patients with SLE versus HCs and in changes from baseline at week 12 between baricitinib 2 mg, 4 mg and placebo groups using a restricted maximum likelihood-based mixed models for repeated measures. Spearman correlations were computed for analytes and clinical measurements.

RESULTS

At baseline, SLE sera had strong cytokine dysregulation relative to HC sera. C-C motif chemokine ligand (CCL) 19, C-X-C motif chemokine ligand (CXCL) 10, tumour necrosis factor alpha (TNF-α), TNF receptor superfamily member (TNFRSF)9/CD137, PD-L1, IL-6 and IL-12β were significantly reduced in patients treated with baricitinib 4 mg versus placebo at week 12. Inflammatory biomarkers indicated correlations/associations with type I IFN (CCL19, CXCL10, TNF-α and PD-L1), anti-double stranded DNA (dsDNA) (TNF-α, CXCL10) and Systemic Lupus Erythematosus Disease Activity Index-2000, tender and swollen joint count and worst joint pain (CCL19, IL-6 and TNFRSF9/CD137).

CONCLUSION

These results suggest that baricitinib 4 mg downregulated key cytokines that are upregulated in patients with SLE and may play a role in a multitargeted mechanism beyond the IFN signature although clinical relevance remains to be further delineated.

TRIAL REGISTRATION NUMBER

NCT02708095.

Baricitinib decreases anti-dsDNA in patients with systemic lupus erythematosus: results from a phase II double-blind, randomized, placebo-controlled trial

Background

Patients with systemic lupus erythematosus (SLE) have substantial unmet medical need. Baricitinib is a Janus kinase (JAK)1 and 2 inhibitor that was shown to have therapeutic benefit in patients with SLE in a phase II clinical trial. The purpose of this study was to evaluate the median change from baseline in conventional serologic biomarkers in subgroups and the overall population of baricitinib-treated patients with SLE, and the SLE Responder Index-4 (SRI-4) response by normalization of anti-dsDNA.

Methods

Data were assessed from the phase II trial I4V-MC-JAHH (NCT02708095). The median change from baseline in anti-dsDNA, IgG, and other conventional serologic markers was evaluated over time in patients who had elevated levels of markers at baseline, and in all patients for IgG. Median change from baseline for baricitinib treatments were compared with placebo. Among patients who were anti-dsDNA positive at baseline, SRI-4 responder rate was compared for those who stayed positive or achieved normal levels by week 24.

Results

Significant decreases of anti-dsDNA antibodies were observed in response to baricitinib 2 mg and 4 mg compared to placebo beginning at weeks 2 (baricitinib 2 mg = − 14.3 IU/mL, placebo = 0.1 IU/mL) and 4 (baricitinib 4 mg = − 17.9 IU/mL, placebo = 0.02 IU/mL), respectively, continuing through week 24 (baricitinib 2 mg = − 29.6 IU/mL, baricitinib 4 mg = − 15.1 IU/mL, placebo=3.0 IU/mL). Significant reductions from baseline of IgG levels were found for baricitinib 4 mg-treated patients compared to placebo at weeks 12 (baricitinib 4 mg = − 0.65 g/L, placebo = 0.09 g/L) and 24 (baricitinib 4 mg = − 0.60 g/L, placebo = − 0.04 g/L). For patients who were anti-dsDNA positive at baseline, no relationship between achieving SRI-4 responder and normalization of anti-dsDNA was observed by week 24.

Conclusions

Baricitinib treatment resulted in a rapid and sustained significant decrease in anti-dsDNA antibodies compared to placebo among those with positive anti-dsDNA antibodies at baseline, as well as a significant decrease in IgG levels in the 4 mg group at weeks 12 and 24. These data suggest that baricitinib may influence B cell activity in SLE. Further studies are needed to evaluate if reductions in anti-dsDNA levels with baricitinib treatment reflect the impact of baricitinib on B cell activity.

Trial registration

NCT02708095.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13075-022-02794-x.

Early and Rapid Identification of COVID-19 Patients with Neutralizing Type I Interferon Auto-antibodies

Purpose

Six to 19% of critically ill COVID-19 patients display circulating auto-antibodies against type I interferons (IFN-AABs). Here, we establish a clinically applicable strategy for early identification of IFN-AAB-positive patients for potential subsequent clinical interventions.

Methods

We analyzed sera of 430 COVID-19 patients from four hospitals for presence of IFN-AABs by ELISA. Binding specificity and neutralizing activity were evaluated via competition assay and virus-infection-based neutralization assay. We defined clinical parameters associated with IFN-AAB positivity. In a subgroup of critically ill patients, we analyzed effects of therapeutic plasma exchange (TPE) on the levels of IFN-AABs, SARS-CoV-2 antibodies and clinical outcome.

Results

The prevalence of neutralizing AABs to IFN-α and IFN-ω in COVID-19 patients from all cohorts was 4.2% (18/430), while being undetectable in an uninfected control cohort. Neutralizing IFN-AABs were detectable exclusively in critically affected (max. WHO score 6–8), predominantly male (83%) patients (7.6%, 18/237 for IFN-α-AABs and 4.6%, 11/237 for IFN-ω-AABs in 237 patients with critical COVID-19). IFN-AABs were present early post-symptom onset and at the peak of disease. Fever and oxygen requirement at hospital admission co-presented with neutralizing IFN-AAB positivity. IFN-AABs were associated with lower probability of survival (7.7% versus 80.9% in patients without IFN-AABs). TPE reduced levels of IFN-AABs in three of five patients and may increase survival of IFN-AAB-positive patients compared to those not undergoing TPE.

Conclusion

IFN-AABs may serve as early biomarker for the development of severe COVID-19. We propose to implement routine screening of hospitalized COVID-19 patients for rapid identification of patients with IFN-AABs who most likely benefit from specific therapies.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10875-022-01252-2.

Antigen-experienced CXCR5- CD19low B cells are plasmablast precursors expanded in SLE

OBJECTIVES

Altered composition of the B cell compartment in the pathogenesis of systemic lupus erythematosus (SLE) is characterized by expanded plasmablast (PB) and IgD^- CD27^- double negative (DN) B cell populations. Previous studies showed that DN B cells represent a heterogeneous subset and further characterization is needed.

METHODS

Therefore, we analyzed two independent cohorts of healthy donors and SLE patients using a combined approach of flow (HD: n=16; SLE: n=28,) and mass cytometry (HD: n=18; SLE: n=24) and targeted RNA sequencing. To study B cell subsets formation in acute immune response versus autoimmunity we investigated HDs at various time points upon vaccination with BNT162b2 or during acute COVID-19 infection using flow cytometry.

RESULTS

We have found that IgD^- CD27⁺ switched and atypical IgD^- CD27^- memory B cells, which are increased in SLE, represent heterogeneous populations composed of three different subsets each. Populations of CXCR5⁺ CD19^int , CXCR5^- CD19^high and CXCR5^- CD19^low are found in both compartments suggesting their relationship. We characterize a hitherto unknown and antigen-experienced CXCR5^- CD19^low subset enhanced in SLE carrying a PB phenotype with diminished B cell receptor responsiveness and expression of CD38, CD95, CD71, PRDM1, XBP-1, and IRF4. CXCR5^- CD19^low subsets are increased and correlate with PB frequencies in SLE and upon BNT162b2-vaccination of HD suggesting their interrelationship and contribution to plasmacytosis. The demonstration of CXCR5^- CD19^low B cells amongst both CD27+ and CD27- cells questions the role of CD27 as reliable marker for B cell differentiation.

CONCLUSION

Our data suggest that CXCR5^- CD19^low B cells are precursors of plasmablasts, thus co-targeting this subset may have therapeutic value in SLE.

Biological impact of iberdomide in patients with active systemic lupus erythematosus

OBJECTIVES

Iberdomide is a high-affinity cereblon ligand that promotes proteasomal degradation of transcription factors Ikaros (IKZF1) and Aiolos (IKZF3). Pharmacodynamics and pharmacokinetics of oral iberdomide were evaluated in a phase 2b study of patients with active systemic lupus erythematosus (SLE).

METHODS

Adults with autoantibody-positive SLE were randomised to placebo (n=83) or once daily iberdomide 0.15 mg (n=42), 0.3 mg (n=82) or 0.45 mg (n=81). Pharmacodynamic changes in whole blood leucocytes were measured by flow cytometry, regulatory T cells (Tregs) by epigenetic assay, plasma cytokines by ultrasensitive cytokine assay and gene expression by Modular Immune Profiling.

RESULTS

Iberdomide exhibited linear pharmacokinetics and dose-dependently modulated leucocytes and cytokines. Compared with placebo at week 24, iberdomide 0.45 mg significantly (p<0.001) reduced B cells, including those expressing CD268 (TNFRSF13C) (-58.3%), and plasmacytoid dendritic cells (-73.9%), and increased Tregs (+104.9%) and interleukin 2 (IL-2) (+144.1%). Clinical efficacy was previously reported in patients with high IKZF3 expression and high type I interferon (IFN) signature at baseline and confirmed here in those with an especially high IFN signature. Iberdomide decreased the type I IFN gene signature only in patients with high expression at baseline (-81.5%; p<0.001) but decreased other gene signatures in all patients.

CONCLUSION

Iberdomide significantly reduced activity of type I IFN and B cell pathways, and increased IL-2 and Tregs, suggesting a selective rebalancing of immune abnormalities in SLE. Clinical efficacy corresponded to reduction of the type I IFN gene signature.

TRIAL REGISTRATION NUMBER

NCT03161483.

B Cell Characteristics at Baseline Predict Vaccination Response in RTX Treated Patients

Background

Vaccination is considered as most efficient strategy in controlling SARS-CoV-2 pandemic spread. Nevertheless, patients with autoimmune inflammatory rheumatic diseases receiving rituximab (RTX) are at increased risk to fail humoral and cellular responses upon vaccination. The ability to predict vaccination responses is essential to guide adequate safety and optimal protection in these patients.

Methods

B- and T- cell data before vaccination were evaluated for characteristics predicting vaccine responses in altogether 15 patients with autoimmune inflammatory rheumatic diseases receiving RTX. Eleven patients with rheumatoid arthritis (RA) on other therapies, 11 kidney transplant recipients (KTR) on regular immunosuppression and 15 healthy controls (HC) served as controls. A multidimensional analysis of B cell subsets via UMAP algorithm and a correlation matrix were performed in order to identify predictive markers of response in patients under RTX therapy.

Results

Significant differences regarding absolute B cell counts and specific subset distribution pattern between the groups were identified at baseline. In this context, the majority of B cells from vaccination responders of the RTX group (RTX IgG+) were naïve and transitional B cells, whereas vaccination non-responders (RTX IgG-) carried preferentially plasmablasts and double negative (CD27-IgD-) B cells. Moreover, there was a positive correlation between neutralizing antibodies and B cells expressing HLA-DR and CXCR5 as well as an inverse correlation with CD95 expression and CD21low expression by B cells among vaccination responders.

Summary

Substantial repopulation of the naïve B cell compartment after RTX therapy appeared to be essential for an adequate vaccination response, which seem to require the additional capability of antigen presentation and germinal center formation. Moreover, expression of exhaustion markers represent negative predictors of vaccination responses.

CD39 and CD326 Are Bona Fide Markers of Murine and Human Plasma Cells and Identify a Bone Marrow Specific Plasma Cell Subpopulation in Lupus

Antibody-secreting cells (ASCs) contribute to immunity through production of antibodies and cytokines. Identification of specific markers of ASC would allow selective targeting of these cells in several disease contexts. Here, we performed an unbiased, large-scale protein screening, and identified twelve new molecules that are specifically expressed by murine ASCs. Expression of these markers, particularly CD39, CD81, CD130, and CD326, is stable and offers an improved resolution for ASC identification. We accessed their expression in germ-free conditions and in T cell deficient mice, showing that at least in part their expression is controlled by microbial- and T cell-derived signals. Further analysis of lupus mice revealed the presence of a subpopulation of LAG-3– plasma cells, co-expressing high amounts of CD39 and CD326 in the bone marrow. This population was IgM+ and correlated with IgM anti-dsDNA autoantibodies in sera. Importantly, we found that CD39, CD81, CD130, and CD326 are also expressed by human peripheral blood and bone marrow ASCs. Our data provide innovative insights into ASC biology and function in mice and human, and identify an intriguing BM specific CD39++CD326++ ASC subpopulation in autoimmunity.

[B lymphocytes and plasma cells as drivers of rheumatic diseases]

Verschiedene Arbeitsgruppen am Deutschen Rheuma-Forschungszentrum Berlin haben in enger Zusammenarbeit mit der Medizinischen Klinik mit Schwerpunkt Rheumatologie und Klinische Immunologie an der Charité wichtige Beiträge zur Bedeutung der B‑Zellen und Plasmazellen bei rheumatischen Erkrankungen geleistet, die nicht nur für die Rheumatologie, sondern für alle klinischen Fachgebiete, in denen antikörpervermittelte Erkrankungen eine Rolle spielen, relevant sind. Insbesondere wird auf die gestörte B‑Zell-Homöostase, die Bedeutung des Immunglobulin M(IgM)-Fc-Rezeptors für die Regulation der Autoimmunität, die Rolle der langlebigen Gedächtnis-Plasmazelle bei der Aufrechterhaltung der Autoimmunität sowie die Sicherung ihres Überlebens in speziellen, von Stromazellen organisierten Nischen im Knochenmark und in entzündeten Geweben eingegangen. Die Forschungsergebnisse haben zu einem besseren Verständnis der immunologischen und molekularen Mechanismen bei rheumatischen Erkrankungen und ihrer Therapie beigetragen. Die Identifizierung der langlebigen Gedächtnis-Plasmazelle hat zu vielversprechenden therapeutischen Ansätzen mit kurativem Potenzial bei Autoimmunerkrankungen geführt.

A Narrative Literature Review Comparing the Key Features of Musculoskeletal Involvement in Rheumatoid Arthritis and Systemic Lupus Erythematosus

Although the clinical approach to the management of musculoskeletal manifestations in systemic lupus erythematosus (SLE) is often similar to that of rheumatoid arthritis (RA), there are distinct differences in immunopathogenesis, structural and imaging phenotypes and therapeutic evidence. Additionally, there are few published comparisons of these diseases. The objective of this narrative literature review is to compare the immunopathogenesis, structural features, magnetic resonance imaging (MRI) and musculoskeletal ultrasound (MSUS) studies and management of joint manifestations in RA and SLE. We highlight the key similarities and differences between the two diseases. Overall, the literature evaluated indicates that synovitis and radiographical progression are the key features in RA, while inflammation without swelling, tendinitis and tenosynovitis are more prominent features in SLE. In addition, the importance of defining patients with RA by the presence or absence of autoantibodies and categorizing patients with SLE by synovitis detected by musculoskeletal ultrasound and by structural phenotype (non-deforming, non-erosive arthritis, Jaccoud’s arthropathy and ‘Rhupus’) with respect to joint manifestations will also be discussed. An increased understanding of the joint manifestations in RA and SLE may inform evidence-based clinical decisions for both diseases.

Temporary antimetabolite treatment hold boosts SARS-CoV-2 vaccination-specific humoral and cellular immunity in kidney transplant recipients

Transplant recipients exhibit an impaired protective immunity after SARS-CoV-2 vaccination, potentially caused by mycophenolate (MPA) immunosuppression. Recent data from patients with autoimmune disorders suggest that temporary MPA hold might greatly improve booster vaccination outcomes. We applied a fourth dose of SARS-CoV-2 vaccine to 29 kidney transplant recipients during a temporary (5 weeks) MPA/azathioprine hold, who had not mounted a humoral immune response to previous vaccinations. Seroconversion until day 32 after vaccination was observed in 76% of patients, associated with acquisition of virus-neutralizing capacity. Interestingly, 21/25 (84%) calcineurin inhibitor–treated patients responded, but only 1/4 belatacept-treated patients responded. In line with humoral responses, counts and relative frequencies of spike receptor binding domain–specific (RBD-specific) B cells were markedly increased on day 7 after vaccination, with an increase in RBD-specific CD27⁺⁺CD38⁺ plasmablasts. Whereas overall proportions of spike-reactive CD4⁺ T cells remained unaltered after the fourth dose, frequencies were positively correlated with specific IgG levels. Importantly, antigen-specific proliferating Ki67⁺ and in vivo–activated programmed cell death 1–positive T cells significantly increased after revaccination during MPA hold, whereas cytokine production and memory differentiation remained unaffected. In summary, antimetabolite hold augmented all arms of immunity during booster vaccination. These data suggest further studies of antimetabolite hold in kidney transplant recipients.

Phase 2 Trial of Iberdomide in Systemic Lupus Erythematosus

BACKGROUND

Iberdomide, a cereblon modulator promoting degradation of the transcription factors Ikaros and Aiolos, which affect leukocyte development and autoimmunity, is being evaluated for the treatment of systemic lupus erythematosus (SLE).

METHODS

In this phase 2 trial, we randomly assigned patients in a 2:2:1:2 ratio to receive oral iberdomide (at a dose of 0.45, 0.30, or 0.15 mg) or placebo once daily for 24 weeks, in addition to standard medications. The primary end point at week 24 was a response on the SLE Responder Index (SRI-4), which was defined as a reduction of at least 4 points in the Systemic Lupus Erythematosus Disease Activity Index 2000 score (a 24-item weighted score of lupus activity that ranges from 0 to 105, with higher scores indicating greater disease activity), no new disease activity as measured on the British Isles Lupus Assessment Group 2004 index, and no increase of 0.3 points or more in the Physician's Global Assessment score (on a visual-analogue scale ranging from 0 [no disease activity] to 3 [maximal disease]).

RESULTS

A total of 288 patients received the assigned intervention: 81 received iberdomide at a dose of 0.45 mg, 82 received iberdomide at a dose of 0.30 mg, 42 received iberdomide at a dose of 0.15 mg, and 83 received placebo. At week 24, the percentages of patients with an SRI-4 response were 54% in the iberdomide 0.45-mg group, 40% in the iberdomide 0.30-mg group, 48% in the iberdomide 0.15-mg group, and 35% in the placebo group (adjusted difference between the iberdomide 0.45-mg group and the placebo group, 19.4 percentage points; 95% confidence interval, 4.1 to 33.4; P = 0.01), with no significant differences between the groups that received the lower doses of iberdomide and the group that received placebo. Iberdomide-associated adverse events included urinary tract and upper respiratory tract infections and neutropenia.

CONCLUSIONS

In this 24-week, phase 2 trial involving patients with SLE, iberdomide at a dose of 0.45 mg resulted in a higher percentage of patients with an SRI-4 response than did placebo. Data from larger, longer trials are needed to determine the efficacy and safety of iberdomide in SLE. (Funded by Bristol Myers Squibb; ClinicalTrials.gov number, NCT03161483; EudraCT number, 2016-004574-17.).

Resident memory CD4+ T lymphocytes mobilize from bone marrow to contribute to a systemic secondary immune reaction

Resident memory T lymphocytes (T_RM ) of epithelial tissues and the bone marrow protect their host tissue. To what extent these cells are mobilized and contribute to systemic immune reactions is less clear. Here we show that in secondary immune reactions to the measles-mumps-rubella (MMR) vaccine, CD4⁺ T_RM are mobilized into the blood within 16 to 48 hours after immunization in humans. This mobilization of T_RM is cognate: T_RM recognizing other antigens are not mobilized, unless they cross-react with the vaccine. We also demonstrate through methylome analyses that T_RM are mobilized from the bone marrow. These mobilized cells make significant contribution to the systemic immune reaction, as evidenced by their T-cell receptor Vβ clonotypes represented among the newly generated circulating memory T-cells, 14 days after vaccination. Thus, T_RM of the bone marrow confer not only local, but also systemic immune memory. This article is protected by copyright. All rights reserved.

B cells in systemic lupus erythematosus

PURPOSE OF REVIEW

New insight into altered B cell distribution including newly identified subsets and abnormalities in systemic lupus erythematosus (SLE) as well as their role in immune protection are summarized in this review.

RECENT FINDINGS

SLE carries characteristic B cell abnormalities, which offer new insights into B cell differentiation and their disturbances including discoveries of pathogenic B cell subsets and intrinsic B cell abnormalities. A recent study in SLE found that antigen-experienced B cell subsets lacking expression of CD27 and IgD defined by their lack of CXCR5 and CD19low expression are expanded in SLE and represent plasmablasts likely escaping proper selection. In terms of therapeutic targeting with broader coverage than rituximab, second-generation anti-CD20, anti-CD38 and CD19-CART treatment experiences have advanced our understanding recently. However, the key role of qualitative and quantitative B cell requirements in connection with T cells became apparent during SARS-Cov2 infection and vaccination, especially in patients with gradual B cell impairments by rituximab, mycophenolate mofetil and cyclophosphamide.

SUMMARY

Identification and characterization relevant B cell subsets together with altered regulatory mechanisms in SLE facilitates new approaches in targeting pathogenic B cells but require consideration of preservation of protection.

Safety and efficacy of subcutaneous ianalumab (VAY736) in patients with primary Sjögren's syndrome: a randomised, double-blind, placebo-controlled, phase 2b dose-finding trial

BACKGROUND

Sjögren's syndrome is an autoimmune disease characterised by dry eyes and mouth, systemic features, and reduced quality of life. There are no disease-modifying treatments. A new biologic, ianalumab (VAY736), with two modes of suppressing B cells, has previously shown preliminary efficacy. This dose-finding trial aimed to assess the safety and efficacy of different subcutaneous doses of ianalumab in patients with moderate to severe primary Sjögren's syndrome.

METHODS

VAY736A2201 was a randomised, parallel, double-blind, placebo-controlled, phase 2b dose-finding study done in 56 centres in 19 countries. Patients aged 18-75 years with primary Sjögren's syndrome with moderate to severe disease activity (European Alliance of Associations for Rheumatology [EULAR] Sjögren's Syndrome Disease Activity Index [ESSDAI] score ≥6) and symptom severity (EULAR Sjögren's Syndrome Patient Reported Index score ≥5) were eligible. Participants were randomly assigned (1:1:1:1) to receive subcutaneous placebo or ianalumab (5 mg, 50 mg, or 300 mg) every 4 weeks for 24 weeks using a secure, online randomisation system. Randomisation was stratified by the ESSDAI score at baseline (≥10 or <10). Study personnel and patients were masked to treatment assignment. The primary outcome was the change in ESSDAI score from baseline to 24 weeks in all randomly assigned patients. Dose-related change in disease activity (ESSDAI) from baseline at week 24 was assessed by multiple comparison procedure with modelling analysis. Safety was measured in all patients who received at least one dose of study drug. This trial is registered with ClinicalTrials.gov, NCT02962895.

FINDINGS

Between June 27, 2017, and Dec 06, 2018, 293 patients were screened, 190 of whom were randomly assigned (placebo n=49, ianalumab 5 mg n=47, ianalumab 50 mg n=47, ianalumab 300 mg n=47). Statistically significant dose-responses were seen for overall disease activity (ESSDAI score) in four of the five dose-response models tested (p<0·025 in four models, p=0·060 in one model). The ESSDAI score decreased from baseline in all ianalumab groups, with the maximal ESSDAI score change from baseline observed in the ianalumab 300 mg group: placebo-adjusted least-squares mean change from baseline -1·92 points (95% CI -4·15 to 0·32; p=0·092). There were four serious adverse events in three patients considered treatment-related (pneumonia [n=1] and gastroenteritis [n=1] in the placebo group; appendicitis plus tubo-ovarian abscess in the same patient in the ianalumab 50 mg group).

INTERPRETATION

The study met its primary objective, showing a dose-related decrease in disease activity as measured by ESSDAI at week 24. Overall, ianalumab was well tolerated and safe, with no increase in infections. To our knowledge, this is the first large, randomised, controlled trial in primary Sjögren's syndrome that met its primary endpoint, and its results mean there is potential for more studies of this mechanism in the future.

FUNDING

Novartis.

B cell numbers predict humoral and cellular response upon SARS-CoV-2 vaccination among patients treated with rituximab

OBJECTIVES

Patients with autoimmune inflammatory rheumatic diseases receiving rituximab (RTX) therapy are at higher risk for poor COVID-19 outcomes and show substantially impaired humoral anti-SARS-CoV-2 vaccine responses. However, the complex relationship between antigen-specific B and T cells and the level of B cell repopulation necessary to achieve anti-vaccine responses remain largely unknown.

METHODS

Antibody responses to SARS-CoV-2 vaccines and induction of antigen-specific B and CD4/CD8 T cell subsets were studied in 19 rheumatoid arthritis (RA) and ANCA-associated vasculitis (AAV) patients receiving RTX, 12 RA patients on other therapies and 30 healthy controls after SARS-CoV-2 vaccination with either mRNA or vector based vaccines.

RESULTS

A minimum of 10 B cells/μL (0,4% of lymphocytes) in the peripheral circulation appeared to be required in RTX patients to mount seroconversion to anti-S1 IgG upon SARS-CoV-2 vaccination. RTX patients lacking IgG seroconversion showed reduced RBD+ B cells, lower frequency of TfH-like cells as well as less activated CD4 and CD8 T cells compared to IgG seroconverted RTX patients. Functionally relevant B cell depletion resulted in impaired IFNγ secretion by spike-specific CD4 T cells. In contrast, antigen-specific CD8 T cells were reduced in patients, independently of IgG formation.

CONCLUSIONS

In patients receiving RTX, a minimum of 10 B cells/μl in the peripheral circulation candidates as biomarker for a high likelihood of an appropriate cellular and humoral response after SARS-CoV-2 vaccination. Mechanistically, the data emphasize the crucial role of co-stimulatory B cell functions for the proper induction of CD4 responses propagating vaccine-specific B and plasma cell differentiation.

B- and Plasma Cell Subsets in Autoimmune Diseases: Translational Perspectives

B lymphocytes play a central role in immunity owing to their unique antibody-producing capacity that provides protection against certain infections and during vaccination. In autoimmune diseases, B cells can gain pathogenic relevance through autoantibody production, antigen presentation, and proinflammatory cytokine secretion. Recent data indicate that B and plasma cells can function as regulators through the production of immunoregulatory cytokines and/or employing checkpoint molecules. In this study, we review the key findings that define subsets of B and plasma cells with pathogenic and protective functions in autoimmunity. In addition to harsh B-cell depletion, we discuss the strategies that have the potential to reinstall the balance of pathogenic and protective B cells with the potential of more specific and personalized therapies.

B and T Cell Responses after a Third Dose of SARS-CoV-2 Vaccine in Kidney Transplant Recipients

BACKGROUND

Accumulating evidence sugges ts solid organ transplant recipients, as opposed to the general population, show strongly impaired responsiveness toward standard SARS-CoV-2 mRNA-based vaccination, demanding alternative strategies for protectio n o f this vulnerable group.

METHODS

In line with recent recommendations, a third dose of either heterologous ChAdOx1 (AstraZeneca) or homologous BNT162b2 (BioNTech) was administered to 25 kidney transplant recipients (KTR) without humoral response after two doses of BNT162b2, followed by analysis of serological responses and vaccine-specific B- and T-cell immunity.

RESULTS

Nine out of 25 (36%) KTR under standard immunosuppressive treatment seroconverted until day 27 after the third vaccination, whereas one patient developed severe COVID-19 infection immediately after vaccination. Cellular analysis 7 days after the third dose showed significantly elevated frequencies of viral spike-protein receptor-binding domain-specific B cells in humor al responders as compared with nonresponders. Likewise, portions of spike-reactive CD4 + T helper cells were significantly elevated in patients who were seroconverting. Furthermore, overall frequencies of IL-2 + , IL-4 + , and polyfunctional CD4 + T cells significantly increased after the third dose, whereas memory/effector differentiation remained unaffected.

CONCLUSIONS

Our data suggest a fraction of transplant recipients benefit from triple vaccination, where seroconversion is associated with quantitative and qualitative changes of cellular immunity. At the same time, the study highlights that modified vaccination approaches for immunosuppressed patients remain an urgent medical need.

PODCAST

This article contains a podcast at https://www.asn-online.org/media/podcast/JASN/2021_11_23_briggsgriffin112321.mp3.

Guidelines for the use of flow cytometry and cell sorting in immunological studies (third edition)

The third edition of Flow Cytometry Guidelines provides the key aspects to consider when performing flow cytometry experiments and includes comprehensive sections describing phenotypes and functional assays of all major human and murine immune cell subsets. Notably, the Guidelines contain helpful tables highlighting phenotypes and key differences between human and murine cells. Another useful feature of this edition is the flow cytometry analysis of clinical samples with examples of flow cytometry applications in the context of autoimmune diseases, cancers as well as acute and chronic infectious diseases. Furthermore, there are sections detailing tips, tricks and pitfalls to avoid. All sections are written and peer-reviewed by leading flow cytometry experts and immunologists, making this edition an essential and state-of-the-art handbook for basic and clinical researchers.