Serum and Tissue Biomarkers Associated With Composite of Relevant Endpoints for Sjögren Syndrome (CRESS) and Sjögren Tool for Assessing Response (STAR) to B Cell-Targeted Therapy in the Trial of Anti-B Cell Therapy in Patients With Primary Sjögren Syndrome (TRACTISS)

OBJECTIVE

This study aimed to identify peripheral and salivary gland (SG) biomarkers of response/resistance to B cell depletion based on the novel concise Composite of Relevant Endpoints for Sjögren Syndrome (cCRESS) and candidate Sjögren Tool for Assessing Response (STAR) composite endpoints.

METHODS

Longitudinal analysis of peripheral blood and SG biopsies was performed pre- and post-treatment from the Trial of Anti-B Cell Therapy in Patients With Primary Sjögren Syndrome (TRACTISS) combining flow cytometry immunophenotyping, serum cytokines, and SG bulk RNA sequencing.

RESULTS

Rituximab treatment prevented the worsening of SG inflammation observed in the placebo arm, by inhibiting the accumulation of class-switched memory B cells within the SG. Furthermore, rituximab significantly down-regulated genes involved in immune-cell recruitment, lymphoid organization alongside antigen presentation, and T cell co-stimulatory pathways. In the peripheral compartment, rituximab down-regulated immunoglobulins  and auto-antibodies together with pro-inflammatory cytokines and chemokines. Interestingly, patients classified as responders  according to STAR displayed significantly higher baseline levels of C-X-C motif chemokine ligand-13 (CXCL13), interleukin (IL)-22, IL-17A, IL-17F, and tumor necrosis factor-α (TNF-α), whereas a longitudinal analysis of serum T cell-related cytokines showed a selective reduction in both STAR and cCRESS responder patients. Conversely, cCRESS response was better associated with biomarkers of SG immunopathology, with cCRESS-responders showing a significant decrease in SG B cell infiltration and reduced expression of transcriptional gene modules related to T cell costimulation, complement activation, and Fcγ-receptor engagement. Finally, cCRESS and STAR response were associated with a significant improvement in SG exocrine function linked to transcriptional evidence of SG epithelial and metabolic restoration.

CONCLUSION

Rituximab modulates both peripheral and SG inflammation, preventing the deterioration of exocrine function with functional and metabolic restoration of the glandular epithelium. Response assessed by newly developed cCRESS and STAR criteria was associated with differential modulation of peripheral and SG biomarkers, emerging as novel tools for patient stratification.

High BMI is associated with lower TNF-α inhibitor serum trough levels and higher disease activity in patients with axial spondyloarthritis

BACKGROUND

TNF-α inhibitor (TNFi) serum trough levels have previously been found to be related to disease activity in axial spondyloarthritis (axSpA). However, most research regarding serum trough levels has been conducted in patients who only recently started TNFi therapy. Therefore, our objective was to explore TNFi serum trough level measurements in relation to disease activity and BMI in the total axSpA population in daily clinical practice, also including patients on long-term TNFi therapy.

METHODS

Consecutive patients from the Groningen Leeuwarden Axial Spondyloarthritis (GLAS) cohort were approached for a TNFi serum trough level measurement during their regular outpatient visit at the UMCG. Spearman's correlation coefficient was used to analyse the relation of serum trough levels with disease activity and BMI. Logistic regression was performed to analyse the relation between therapeutic drug levels and disease activity, corrected for potential confounders, including BMI.

RESULTS

Thirty-four patients on adalimumab and 21 patients on etanercept were included. Mean age was 45 ± 12 years, 47% were male, median BMI was 26.4 (IQR 23.9-32.5) and median treatment duration was 41 months (range 2-126). According to definitions of Sanquin, 47% of patients had therapeutic serum trough levels. No significant correlations were found between TNFi levels and disease activity (ASDAS-CRP: adalimumab: ρ = -0.16, p = 0.39; etanercept: ρ = -0.29, p = 0.20). TNFi levels were moderately correlated with BMI (adalimumab: ρ = -0.48, p = 0.004; etanercept: ρ = -0.50, p = 0.021). Patients with active disease (ASDAS ≥ 2.1) showed higher BMI than patients with inactive disease (median 29.7 vs. 24.6, p = 0.015). In multivariable regression analyses, BMI was identified as the only confounder for the relationship between therapeutic drug levels and ASDAS.

CONCLUSION

In this cross-sectional, observational study of axSpA patients mainly on long-term treatment with TNFi, higher BMI was significantly associated with lower adalimumab and etanercept serum trough levels and higher disease activity.

Why do drug treatments fail in Sjögren's disease? Considerations for treatment, trial design and interpretation of clinical efficacy

INTRODUCTION

Despite ongoing efforts to develop effective therapeutics, no disease-modifying drugs have been officially licensed for the indication of Sjögren's disease (SjD). This is partly due to heterogeneity in disease manifestations, which complicates drug target selection, trial design and interpretation of clinical efficacy in SjD.

AREAS COVERED

Here, we summarize developments and comment on challenges in 1) identifying the right target for treatment, 2) selection of the primary study endpoint for trials and definition of clinically relevant response to treatment, 3) inclusion criteria and patient stratification, 4) distinguishing between disease activity and damage and 5) establishing the effect of treatment considering measurement error, natural variation, and placebo or nocebo responses.

EXPERT OPINION

Targets that are involved in both the immune cell response and dysregulation of glandular epithelial cells (e.g. B-lymphocytes, type-I interferon) are of particular interest to treat both glandular and extra-glandular manifestations of SjD. The recent development of composite study endpoints (CRESS and STAR) may be a crucial step forward in the search for clinically effective systemic treatment of patients with SjD. Important additional areas for future research are symptom-based and/or molecular pathway-based patient stratification, prevention of irreversible damage, and establishing the effect of treatment.

Association of Circulating Antibody-Secreting Cell Maturity With Disease Features in Primary Sjögren's Syndrome

OBJECTIVE

B cell hyperactivity plays an important role in primary Sjögren's syndrome (SS). We undertook this study to better understand the B cell effector branch, namely antibody-secreting cells (ASCs) in primary SS, and to examine the quantity, maturity, and inflammatory properties of ASCs in primary SS patients.

METHODS

Circulating ASCs, defined as CD3-CD14-CD27+CD38++ cells, from 21 primary SS patients and 10 healthy controls were assessed using spectral flow cytometry. Expression levels of relevant ASC markers relating to maturity, survival, and inflammatory status were analyzed using a t-distributed stochastic neighbor embedding approach. Correlation of ASC properties with primary SS disease parameters was assessed.

RESULTS

ASCs were more abundant in peripheral blood from primary SS patients than from healthy controls (mean ± SD 3.1 ± 5.1 cells/μl versus 1.1 ± 1.0 cells/μl, respectively; P = 0.048) and displayed a more mature phenotype (mean ± SD CD19- ASCs 0.37 ± 1.21 cells/μl versus 0.06 ± 0.11 cells/μl, respectively; P = 0.005). An inflammatory CXCR3+ phenotype of ASCs correlated positively with our newly developed ASC maturity index (r = 0.568, P = 0.007) but correlated negatively with antiinflammatory interleukin-10 expression (r = -0.769, P < 0.001). ASCs with a higher maturity index also demonstrated higher levels of the pro-survival protein myeloid cell leukemia 1 (r = 0.567, P = 0.007). Frequency and/or maturity of ASCs correlated with several primary SS disease parameters, such as antinuclear antibody and anti-La/SSB titers, salivary gland focus scores, and ocular staining scores.

CONCLUSION

Quantity and maturity of ASCs in primary SS patients are increased and correlate with disease parameters. A higher maturity index of ASCs marks a pro-survival and proinflammatory phenotype. Altogether, B cell hyperactivity in primary SS extends to the peripheral ASC compartment, raising potential for ASCs as future biomarkers or targets for primary SS treatment.

Safety and efficacy of SARS-CoV-2 vaccination in 1237 patients with primary Sjögren syndrome

OBJECTIVES

To investigate the safety and efficacy of SARS-Cov-2 vaccination in patients with primary Sjögren syndrome (pSS) due to scarcity of data in this population.

METHODS

By the first week of May 2021, all Big Data SS Consortium centres patients who had received at least one dose of any SARS-CoV-2 vaccine were included in the study. The in-charge physician asked patients about local and systemic reactogenicity to collect SARS-CoV-2 vaccination data.

RESULTS

The vaccination data of 1237 patients were received. A total of 835 patients (67%) reported any adverse events (AEs), including local (53%) and systemic (50%) AEs. Subjective symptoms (63%) were the most common local AEs, followed by objective signs at the injection site (16%), and general symptoms were the most commonly reported systemic AEs (46%), followed by musculoskeletal (25%), gastrointestinal (9%), cardiopulmonary (3%), and neurological (2%). In addition, 141 (11%) patients reported a significant worsening/exacerbation of their pre-vaccination sicca symptoms and fifteen (1.2%) patients reported active involvement in the glandular (n=7), articular (n=7), cutaneous (n=6), pulmonary (n=2), and peripheral nervous system (n=1) domains due to post-vaccination SS flares. In terms of vaccination efficacy, breakthrough SARS-CoV-2 infection was confirmed after vaccination in three (0.24 %) patients, and positive anti-SARS-Cov-2 antibodies were detected in approximately 95% of vaccinated SS patients, according to data available.

CONCLUSIONS

Our data suggest that patients with pSS develop adequate humoral response and no severe AEs after SARS-CoV-2 vaccination and therefore raise no concerns about the vaccine's efficacy or safety profile in this population.

Immunisation with Coronavirus-2 vaccines induces potent antibody responses and does not aggravate the lymphocyte compartment of primary Sjögren's syndrome patients

OBJECTIVES

The peripheral lymphocyte compartment of patients with primary Sjögren's syndrome (pSS) differs strongly from healthy individuals. Whether this altered lymphocyte composition also changes abnormally during immune reactions, especially by novel CoV-2-vaccines, is unknown.

METHODS

Peripheral blood mononuclear cells (PBMC) from 26 pSS patients and 6 healthy controls were compared before Coronavirus-2 (CoV-2) vaccination (Pfizer/BNT162b2, Moderna/mRNA-1273, AstraZeneca/AZD122 ChAdOx1 nCoV-19) and 7 days after secondary vaccination. Spike 1 (S1)-receptor binding domain (RBD)-specific IgG antibodies were measured in serum samples. Among PBMCs, B and T cell subpopulations were phenotypically analysed and RBD-specific B and plasma cells were evaluated.

RESULTS

Immunisation induced CoV-2 specific serum antibodies in all pSS patients and healthy participants. When analysing pSS patients and controls together, frequencies of circulating IgG+ RBD-specific antibody-secreting cells (ASC) and anti-RBD serum titres correlated (r=0.42, p=0.022). Previously described alterations of peripheral B cells in pSS patients (e.g. reduced memory B cells, increased naive and transitional B cells and higher maturity of ASCs) remained stable during vaccination. The subset distribution of CD4+ and CD8+ T cells also stayed largely unchanged. However, frequencies of CD4+CXCR5-PD-1+ circulating peripheral helper T (cTPH)-like cells increased in pSS patients comparing pre- and post-vaccination (p=0.020), while circulating CD4+CXCR5+PD-1+ follicular helper T (cTFH)-like cells declined (p=0.024).

CONCLUSIONS

An immune reaction induced by vaccination with the novel CoV-2 vaccines yields adequate antibody production and vaccine specific lymphocytes in pSS patients and controls. Aberrant lymphocyte subset distribution in pSS patients persisted after vaccination and no major changes were induced despite small changes in cTPH and cTFH cells.

Immunogenicity and safety of COVID-19 vaccination in patients with primary Sjögren's syndrome

Objectives

To evaluate humoral and cellular immune responses and adverse events (AEs) after COVID-19 vaccination in patients with primary Sjögren’s syndrome (pSS) compared to healthy controls (HC), and disease activity following vaccination in patients with pSS.

Methods

67 patients with pSS and 33 HC (ratio 2:1) received COVID-19 vaccinations following the Dutch vaccination programme. Patients with pSS did not use immunomodulatory drugs, except hydroxychloroquine. Anti-spike 1 receptor binding domain IgG serum antibody levels were measured 28 days after complete vaccination. AEs were collected 7 days after vaccination. In a subgroup, salivary anti-SARS-CoV-2 antibodies and T-cell response by interferon-γ enzyme-linked immune absorbent spot was measured.

Results

47 patients with pSS (70%) and 14 HC (42%) received BNT162b2 (Pfizer-BioNtech), 13 (19%) and 5 (15%) received ChAdOx1 nCoV-19 (AstraZeneca), 6 (9%) and 8 (24%) received mRNA-1273 (Moderna), and 1 (1%) and 6 (18%) received Ad.26.COV2.S (Janssen). All participants had positive anti-SARS-CoV-2 antibody levels (>2500 AU/mL) postvaccination. No differences in anti-SARS-CoV-2 antibody levels were observed between patients with pSS and HC, for each vaccine type. Salivary anti-SARS-CoV-2 IgG antibodies also increased, and a T-cell response was observed in patients with pSS and HC. Frequencies of systemic AEs were comparable between patients with pSS and HC (first vaccination: 34/67 (51%) vs 16/33 (48%), p=0.83; second: 41/66 (62%) vs 14/25 (56%), p=0.59). No significant worsening was observed in patient-reported and systemic disease activity, including auto-antibodies.

Conclusions

Patients with pSS had similar humoral and cellular immune responses as HC, suggesting COVID-19 vaccination is effective in patients with pSS. AEs were also comparable, and no increase in disease activity was seen in patients with pSS.

Composite of Relevant Endpoints for Sjögren's Syndrome (CRESS): development and validation of a novel outcome measure

BACKGROUND

Recent randomised controlled trials (RCTs) in primary Sjögren's syndrome used the European League Against Rheumatism (EULAR) Sjögren's Syndrome Disease Activity Index (ESSDAI) as their primary endpoint. Given the heterogeneous and complex nature of primary Sjögren's syndrome, it might be more appropriate to also assess other clinically relevant disease features. We aimed to develop a novel composite endpoint for assessing treatment efficacy in patients with primary Sjögren's syndrome: the Composite of Relevant Endpoints for Sjögren's Syndrome (CRESS).

METHODS

A multidisciplinary expert team selected clinically relevant items and candidate measurements for inclusion in the composite score. For each measurement, cutoff points for response to treatment were chosen based on expert opinion, previously published data on minimal clinically important improvements, and trial data, primarily the week-24 data of the single-centre ASAP-III trial of abatacept versus placebo. CRESS was validated using data from three independent RCTs: one trial of rituximab (TRACTISS), one of abatacept (multinational trial), and one of tocilizumab (ETAP). We calculated the number and percentage of patients who were responders in the separate CRESS items, and the percentage of responders based on the total CRESS at the primary endpoint visits (week 48 for TRACTISS, week 24 for the other two trials). Patients with fewer than three items available for evaluating CRESS response were imputed as non-responders.

FINDINGS

Based on expert opinion, five complementary items were selected to assess response: (1) systemic disease activity by Clinical ESSDAI (less than 5 points); (2) patient-reported symptoms by EULAR Sjögren's Syndrome Patient Reported Index, assessed by a decrease of at least 1 point or at least 15% from baseline; (3) tear gland item by Schirmer's test and ocular staining score, assessed by an increase of at least 5 mm or decrease of at least 2 points, respectively, in patients with abnormal Schirmer's test or ocular staining score findings at baseline, or, in patients with normal baseline values, assessed by no change to abnormal for both; (4) salivary gland item, assessed by unstimulated whole saliva secretion (increase of at least 25%) and salivary gland ultrasonography (decrease of at least 25%); and (5) serology, assessed by rheumatoid factor (decrease of at least 25%) and IgG (decrease of at least 10%). Total CRESS response is defined as response on at least three of five items. Post-hoc assessment of phase 3 trial data showed that CRESS response rates at the primary endpoint visits were 60% (24 of 40) for abatacept versus 18% (seven of 39) for placebo (p<0·0001) in ASAP-III, 49% (33 of 67) for rituximab versus 30% (20 of 66) for placebo (p=0·026) in the TRACTISS trial, 45% (41 of 92) for abatacept versus 32% (30 of 95) for placebo (p=0·067) in the multinational abatacept trial, and 18% (10 of 55) for tocilizumab versus 24% (13 of 55) for placebo (p=0·48) in the ETAP trial.

INTERPRETATION

The CRESS is a feasible, well-balanced, composite endpoint for use in trials of primary Sjögren's syndrome. As a next step, the CRESS will require validation in a prospective RCT.

FUNDING

None.

TRANSLATION

For the Dutch translation of the abstract see Supplementary Materials section.

Ten years of the ESSDAI: is it fit for purpose?

Primary Sjögren's syndrome (pSS) is a very heterogeneous disease with systemic manifestations such as arthritis, skin, lung and renal involvement. To be able to assess systemic disease activity, the EULAR Sjögren's syndrome disease activity index (ESSDAI) was developed for use in daily clinical practice and in clinical trials. Since its development it has been widely used in cohort studies and clinical trials. The ESSDAI gives a systematic overview of a patient's systemic disease activity, which is very useful in daily clinical practice. However, using the ESSDAI as outcome measure in trials has been more challenging. Several RCTs with the ESSDAI as primary endpoint failed and showed large 'response rates' in placebo-treated patients as well. In this review, we discuss what we learned from using the ESSDAI in cohorts and clinical trials. We recommend to use the ESSDAI only in combination with other important outcome measures, such as patient-reported symptoms and glandular function as part of a composite endpoint in clinical trials in pSS patients.