Hydroxychloroquine treatment downregulates systemic interferon activation in primary Sjögren's syndrome in the JOQUER randomized trial

Update on the pathophysiology and treatment of primary Sjögren syndrome

Sjögren syndrome or Sjögren disease is a chronic form of autoimmune epithelitis characterized by lymphocytic infiltration of the exocrine glands, particularly the salivary and lacrimal glands, leading to progressive glandular dysfunction and subsequent xerostomia and xerophthalmia. Other common manifestations include pain and fatigue, various systemic manifestations and non-Hodgkin's lymphoma. Sjögren syndrome is therefore a complex and disabling disease associated with a reduced quality of life and with considerable long-term damage. Most of the available treatments are merely symptomatic with limited efficacy in both preventing glandular damage and suppressing systemic disease activity. In the past 10 years, great progress has been made in understanding the pathophysiology of Sjögren syndrome, opening new avenues towards a more targeted and individualized therapeutic approach to the disease. Indeed, several randomized controlled trials have just been completed or are poised to commence evaluating the effectiveness of novel drugs targeting both innate and adaptive immune pathways, including pro-inflammatory cytokines, the type I interferon system, B cell activation, B cell and T cell co-stimulation pathway, and ectopic germinal centre formation. Novel clinical trials are also ongoing exploring various targeted approaches (that is, IgG recycling inhibition, nuclease therapy and CAR-T cell therapy) for Sjögren syndrome.

Assessment of hydroxychloroquine blood levels in Sjögren's disease patients: drug adherence and clinical associations

Hydroxychloroquine (HCQ) has been used to treat Sjögren's disease (SjD) patients. However, there are no studies evaluating drug adherence through HCQ blood levels, pharmacy refill (PR) and medication adherence questionnaires. The relationship of HCQ blood levels with glandular/extraglandular disease parameters was also poorly assessed. This cross-sectional observational study included 74 adult SjD patients, who were receiving a stable HCQ dose (4-5.5 mg/kg/day, actual weight) for at least 3 months before study inclusion. HCQ blood levels were quantified by high-performance liquid chromatography coupled to mass spectrometry. Adherence was assessed by PR and Medida de Adesão aos Tratamentos (MAT) questionnaire. The following parameters were evaluated: Xerostomia Inventory, Ocular Surface Disease Index, EULAR (European League Against Rheumatism) Sjögren's Syndrome Disease Activity Index, EULAR Sjögren's Syndrome Patient Reported Index, Schirmer's I test and non-stimulated/stimulated salivary flow rates. HCQ blood levels were 775.3(25.0-2,568.6)ng/mL. Eleven patients (14.9%) had HCQ blood levels < 200ng/mL (non-adherent group); 11(14.9%), 200-499ng/mL (sub-therapeutic levels group); and 52(70.2%), ≥ 500ng/mL (adherent group). PR classified incorrectly all non-adherent/sub-therapeutic patients and 2/52(3.9%) adherent patients. Using MAT, the overall misclassification was 24/52(46.2%) in the adherent group, and were correctly identified 9/11(81.8%) patients in non-adherent and 7/11(63.6%) in sub-therapeutic groups. MAT sensitivity and specificity to identify non-adherent/sub-therapeutic patients were 72.7% and 53.9%, respectively. The three groups were comparable regarding glandular/extraglandular disease parameters (p > 0.05). The assessment of HCQ blood levels is a promising tool for evaluating drug adherence in SjD. This is particularly crucial as one-third of patients exhibited non-adherence/sub-therapeutic levels, and neither PR nor MAT reliably identified these patients.

Central sensitization significantly deteriorates functionality and the interpretation of self-reported disease activity in primary Sjögren's syndrome

BACKGROUND

Central sensitization has a major role in health-related parameters in musculoskeletal conditions. There is still a lack of understanding regarding the impact of central sensitization on the interpretation of disease activity and functional disability in primary Sjögren's syndrome (pSS).

METHODS

The Central Sensitization Inventory (CSI) was used to screen for central sensitization. Disease-related parameters, including objective tests, medication use, the EULAR SS Patient Reported Index (ESSPRI), and the EULAR SS Disease Activity Index (ESSDAI), were assessed. Functionality, quality of life, sleep, and mental health were evaluated by the Health Assessment Questionnaire-Disability Index (HAQ-DI), Medical Outcomes Study 36-Item Short Form Health Survey (SF-36), Jenkins Sleep Evaluation Scale (JSS), and Hospital Anxiety and Depression Scale (HADS), respectively. The effect of central sensitization on functionality and disease activity measures was assessed by regression analyses.

RESULTS

The frequency of central sensitization was 65% in patients with pSS (n = 60). Patients with central sensitization had higher HAQ-DI, ESSPRI, HADS, and JSS and lower SF-36 subdomain scores (p < 0.05 for all). A significant positive correlation was observed between the CSI score and the ESSPRI, JSS, HAQ-DI, and HADS scores (Spearman's rho ranging from 0.342 to 0.739). The multiple regression analysis indicated that CSI was independently associated with HAQ-DI (adjusted R2 = 0.19, B = 0.01) and ESSPRI (adjusted R2 = 0.45, B = 0.08) (p < 0.001 for all).

CONCLUSION

This study confirms that central sensitization has a major impact on functionality and the interpretation of self-reported disease activity in pSS. When devising strategies for the management of patients with pSS, it is crucial to consider these close relationships. Key Points • The frequency of central sensitization accompanying primary Sjögren's syndrome is considerable. • Central sensitization was independently associated with functionality and self-reported disease activity assessment. • This close association leads to challenges in functionality, evaluating treatment response, and planning or switching between therapies in primary Sjögren's syndrome.

Effect of acupuncture on regulating IL-17, TNF-ɑ and AQPs in Sjögren's syndrome

AIM

The aim of the study was to observe the effect of acupuncture on regulating interleukin (IL)-17, tumor necrosis factor (TNF)-ɑ, and aquaporins (AQPs) in Sjögren's syndrome (SS) on patients and on non-obese diabetic (NOD) models.

METHODS

Levels of anti-AQP 1, 5, 8, and 9 antibodies, IL-17, and TNF-ɑ in the serum of SS patients were compared prior and following 20 acupuncture treatment visits during 8 weeks. While in murine model, five groups were divided to receive interventions for 4 weeks, including control, model, acupuncture, isoflurane, and hydroxychloroquine. The submaxillofacial gland index, histology, immunohistochemistry of AQP1, 5, salivary flow, together with IL-17, and TNF-ɑ expression in peripheral blood were compared among the groups.

RESULTS

Acupuncture reduced IL-17, TNF-ɑ, and immunoglobin A levels, and numeric analog scale of dryness in 14 patients with SS (p < 0.05). The salivary flow was increased, and the water intake decreased in NOD mice receiving acupuncture treatments. IL-17 and TNF-ɑ levels in peripheral serum were down-regulated (p < 0.05) and AQP1, 5 expression in the submandibular glands up-regulated in mice.

CONCLUSION

The effect on relieving xerostomia with acupuncture may be achieved by up-regulating the expression of AQP1. AQP5, down-regulating levels of IL-17 and TNF-ɑ, and a decrease in inflammation of glands.

MICa/b-dependent activation of natural killer cells by CD64+ inflammatory type 2 dendritic cells contributes to autoimmunity

Primary Sjögren's syndrome (pSS) is an inflammatory autoimmune disorder largely mediated by type I and II interferon (IFN). The potential contribution of innate immune cells, such as natural killer (NK) cells and dendritic cells (DC), to the pSS pathology remains understudied. Here, we identified an enriched CD16+ CD56hi NK cell subset associated with higher cytotoxic function, as well as elevated proportions of inflammatory CD64+ conventional dendritic cell (cDC2) subtype that expresses increased levels of MICa/b, the ligand for the activating receptor NKG2D, in pSS individuals. Circulating cDC2 from pSS patients efficiently induced activation of cytotoxic NK cells ex vivo and were found in proximity to CD56+ NK cells in salivary glands (SG) from pSS patients. Interestingly, transcriptional activation of IFN signatures associated with the RIG-I/DDX60 pathway, IFN I receptor, and its target genes regulate the expression of NKG2D ligands on cDC2 from pSS patients. Finally, increased proportions of CD64hi RAE-1+ cDC2 and NKG2D+ CD11b+ CD27+ NK cells were present in vivo in the SG after poly I:C injection. Our study provides novel insight into the contribution and interplay of NK and cDC2 in pSS pathology and identifies new potential therapy targets.

Combined use of total glucosides of paeony and hydroxychloroquine in primary Sjögren's syndrome: A systematic review

OBJECTIVE

To assess the effectiveness and safety of the total glucosides of paeony (TGP) combined with hydroxychloroquine (HCQ) on the treatment of primary Sjögren's syndrome (pSS) by conducting a meta-analysis.

METHODS

Eight databases were searched for randomized controlled trials (RCTs) reporting the use of TGP combined with HCQ for pSS, which are before May 10, 2022. Meta-analyses were performed on disappeared clinical symptoms (dry mouth and dry eyes), Schirmer's test, saliva flow test, erythrocyte sedimentation rate (ESR), index of immunoglobulin G (IgG), immunoglobulin M (IgM), immunoglobulin A (IgA), and adverse events (AEs). The Revman 5.4 software was used for this meta-analysis.

RESULTS

Seven RCTs which included 632 participants were identified. The pooled results showed significant differences in clinical symptoms disappear (dry mouth and dry eyes) (p = .0004), IgM (p < .00001), IgA (p < .00001), salivary flow rate (p < .00001) and Schirmer's test (p = .02) in the comparison of TGP combined with HCQ and HCQ alone. For the IgG and ESR, both pooled and subgroup analyses showed that TGP + HCQ was superior to HCQ alone. For the safety analysis, no significant differences in AEs (p = .39) was revealed. The more frequently seen adverse reactions were diarrhea, vomit and there was no severe adverse events were reported in TGP + HCQ group.

CONCLUSION

Therefore, TGP + HCQ can be considered to be a potentially valid and safe combination for the treatment of pSS in the clinic.

Type I Interferons in Autoimmunity: Implications in Clinical Phenotypes and Treatment Response

Type I interferon (IFN-I) is thought to play a role in many systemic autoimmune diseases. IFN-I pathway activation is associated with pathogenic features, including the presence of autoantibodies and clinical phenotypes such as more severe disease with increased disease activity and damage. We will review the role and potential drivers of IFN-I dysregulation in 5 prototypic autoimmune diseases: systemic lupus erythematosus, dermatomyositis, rheumatoid arthritis, primary Sjögren syndrome, and systemic sclerosis. We will also discuss current therapeutic strategies that directly or indirectly target the IFN-I system.

Leflunomide/hydroxychloroquine combination therapy targets type I IFN-associated proteins in patients with Sjögren's syndrome that show potential to predict and monitor clinical response

OBJECTIVES

To assess to what extent leflunomide (LEF) and hydroxychloroquine (HCQ) therapy in patients with primary Sjögren's syndrome (RepurpSS-I) targets type I IFN-associated responses and to study the potential of several interferon associated RNA-based and protein-based biomarkers to predict and monitor treatment.

METHODS

In 21 patients treated with LEF/HCQ and 8 patients treated with placebo, blood was drawn at baseline, 8, 16 and 24 weeks. IFN-signatures based on RNA expression of five IFN-associated genes were quantified in circulating mononuclear cells and in whole blood. MxA protein levels were measured in whole blood, and protein levels of CXCL10 and Galectin-9 were quantified in serum. Differences between responders and non-responders were assessed and receiver operating characteristic analysis was used to determine the capacity of baseline expression and early changes (after 8 weeks of treatment) in biomarkers to predict treatment response at the clinical endpoint.

RESULTS

IFN-signatures in peripheral blood mononuclear cell and whole blood decreased after 24 weeks of LEF/HCQ treatment, however, changes in IFN signatures only poorly correlated with changes in disease activity. In contrast to baseline IFN signatures, baseline protein concentrations of galectin-9 and decreases in circulating MxA and Galectin-9 were robustly associated with clinical response. Early changes in serum Galectin-9 best predicted clinical response at 24 weeks (area under the curve 0.90).

CONCLUSIONS

LEF/HCQ combination therapy targets type-I IFN-associated proteins that are associated with strongly decreased B cell hyperactivity and disease activity. IFN-associated Galectin-9 is a promising biomarker for treatment prediction and monitoring in pSS patients treated with LEF/HCQ.

Chloroquine and Hydroxychloroquine in the Treatment of Dry Eye Disease

The role of chloroquine (CQ) and hydroxychloroquine (HCQ) in the management of dry eye disease is still unclear. This systematic review and meta-analysis investigates the efficacy and feasibility of CQ and HCQ in patients with dry eye disease. In February 2023, PubMed, Embase, Google Scholar, and Web of Science were accessed. Data from 462 patients (mean age 54.4 ± 2.8 years) were collected. Compared to baseline, the tear breakup time (p < 0.0001) and Schirmer I test (p < 0.0001) were significantly increased, and the Ocular Surface Disease Index (OSDI, p < 0.0001) and corneal staining (p < 0.0001) were significantly decreased at the last follow-up in the CQ/HCQ group. At the last follow-up, the OSDI was significantly lower in the CQ/HCQ group compared to the control group (p < 0.0001). Corneal staining was significantly greater in the control group compared to the CQ/HCQ group (p < 0.0001). The Schirmer I test showed no significant difference between the groups (p = 0.2). Altogether, CQ and HCQ improved the symptoms and signs of dry eye disease.

Rheumatologic immune checkpoint inhibitor-related adverse events

PURPOSE OF REVIEW

Immune check point inhibitors (ICIs) are a unique class of cancer treatments that harness the body's innate antitumor response. Although these medications have transformed oncology care, they also lead to generalized immune activation that can result in toxicities across a spectrum of organ systems called immune-related adverse events. This article reviews the most common rheumatologic immune-related adverse events and their management.

RECENT FINDINGS

Inflammatory arthritis, polymyalgia rheumatic, sicca symptoms, systemic sclerosis, myositis, and vasculitis have all been reported as ICI adverse events. Treatment includes nonsteroidal anti-inflammatory drugs, glucocorticoids, traditional DMARDs, and biologics.

SUMMARY

Rheumatologists have an important role in the management of patients with rheumatologic immune-related adverse events. Working with our oncology colleagues, we can help manage rheumatologic immune-related adverse events while optimally preserving ICI's antitumor effects.

Type I interferon pathway assays in studies of rheumatic and musculoskeletal diseases: a systematic literature review informing EULAR points to consider

OBJECTIVES

To systematically review the literature for assay methods that aim to evaluate type I interferon (IFN-I) pathway activation and to harmonise-related terminology.

METHODS

Three databases were searched for reports of IFN-I and rheumatic musculoskeletal diseases. Information about the performance metrics of assays measuring IFN-I and measures of truth were extracted and summarised. A EULAR task force panel assessed feasibility and developed consensus terminology.

RESULTS

Of 10 037 abstracts, 276 fulfilled eligibility criteria for data extraction. Some reported more than one technique to measure IFN-I pathway activation. Hence, 276 papers generated data on 412 methods. IFN-I pathway activation was measured using: qPCR (n=121), immunoassays (n=101), microarray (n=69), reporter cell assay (n=38), DNA methylation (n=14), flow cytometry (n=14), cytopathic effect assay (n=11), RNA sequencing (n=9), plaque reduction assay (n=8), Nanostring (n=5), bisulphite sequencing (n=3). Principles of each assay are summarised for content validity. Concurrent validity (correlation with other IFN assays) was presented for n=150/412 assays. Reliability data were variable and provided for 13 assays. Gene expression and immunoassays were considered most feasible. Consensus terminology to define different aspects of IFN-I research and practice was produced.

CONCLUSIONS

Diverse methods have been reported as IFN-I assays and these differ in what elements or aspects of IFN-I pathway activation they measure and how. No 'gold standard' represents the entirety of the IFN pathway, some may not be specific for IFN-I. Data on reliability or comparing assays were limited, and feasibility is a challenge for many assays. Consensus terminology should improve consistency of reporting.

Association between type I interferon pathway activation and clinical outcomes in rheumatic and musculoskeletal diseases: a systematic literature review informing EULAR points to consider

BACKGROUND

Type I interferons (IFN-I) contribute to a broad range of rheumatic and musculoskeletal diseases (RMDs). Compelling evidence suggests that the measurement of IFN-I pathway activation may have clinical value. Although several IFN-I pathway assays have been proposed, the exact clinical applications are unclear. We summarise the evidence on the potential clinical utility of assays measuring IFN-I pathway activation.

METHODS

A systematic literature review was conducted across three databases to evaluate the use of IFN-I assays in diagnosis and monitor disease activity, prognosis, response to treatment and responsiveness to change in several RMDs.

RESULTS

Of 366 screened, 276 studies were selected that reported the use of assays reflecting IFN-I pathway activation for disease diagnosis (n=188), assessment of disease activity (n=122), prognosis (n=20), response to treatment (n=23) and assay responsiveness (n=59). Immunoassays, quantitative PCR (qPCR) and microarrays were reported most frequently, while systemic lupus erythematosus (SLE), rheumatoid arthritis, myositis, systemic sclerosis and primary Sjögren's syndrome were the most studied RMDs. The literature demonstrated significant heterogeneity in techniques, analytical conditions, risk of bias and application in diseases. Inadequate study designs and technical heterogeneity were the main limitations. IFN-I pathway activation was associated with disease activity and flare occurrence in SLE, but their incremental value was uncertain. IFN-I pathway activation may predict response to IFN-I targeting therapies and may predict response to different treatments.

CONCLUSIONS

Evidence indicates potential clinical value of assays measuring IFN-I pathway activation in several RMDs, but assay harmonisation and clinical validation are urged. This review informs the EULAR points to consider for the measurement and reporting of IFN-I pathway assays.

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.

The inflammatory signature in monocytes of Sjögren's syndrome and systemic lupus erythematosus, revealed by the integrated Reactome and drug target analysis

BACKGROUND

The innate immune regulation, especially by the type I IFN signature in the CD14+ monocytes, is known to be critical in the pathogenesis of autoimmune Sjögren's syndrome (SjS) and systemic lupus erythematosus (SLE).

OBJECTIVE

Since patients with one condition can be overlapped with another, this study is to identify shared differentially expressed genes (DEGs) in SjS and SLE compared to healthy controls (HCs) and refine transcriptomic profiles with the integrated Reactome and gene-drug network analysis for an anti-inflammation therapy.

METHODS

CD14+ monocytes were purified from whole blood of SjS and SLE patients (females, ages from 32 to 62) and subject to bulk RNA-sequencing, followed by data analyses for comparison with HC monocytes (females, ages 30 and 33). Functional categorizations, using Gene Ontology (GO) and the Reactome pathway analysis, were performed and DEGs associated with therapeutic drugs were identified from the Drug Repurposing Hub (DHUB) database.

RESULTS

The GO analysis revealed that DEGs in the inflammatory response and the cellular response to cytokine were highly enriched in both conditions. A propensity toward M1 macrophage differentiation appears to be prominent in SjS while the Response to Virus was significant in SLE monocytes. Through the Reactome pathway analysis, DEGs in the IFN signaling and the cytokine signaling in immune system were most significantly enriched in both. Upregulation of NGF-induced transcription activity in SjS and the complement cascade activity in SLE were also noted. Multiple anti-inflammatory drugs, such as prostaglandin-endoperoxide synthase and angiotensin-I-converting- enzyme were associated with the DEGs in these conditions.

CONCLUSIONS

Taken together, our analysis indicates distinct inflammatory transcriptomic profiles shared in SjS and SLE monocytes. Comprehensive characterizations of the data from these conditions will ultimately allow differential diagnosis of each condition and identification of therapeutic targets.

Efficacy and Safety of Acupuncture on Symptomatic Improvement in Primary Sjögren's Syndrome: A Randomized Controlled Trial

Aim

We sought to evaluate the efficacy of acupuncture in treating the main symptoms of primary Sjögren's syndrome, specifically dryness, pain, and fatigue.

Methods

A total of 120 patients with primary Sjögren's syndrome were randomized in a parallel-group, controlled trial. Participants received acupuncture or sham acupuncture for the first 8 weeks, then were followed for 16 weeks thereafter. The primary outcome was the proportion of participants with a ≥ 30% reduction in ≥ 2 of 3 numeric analog scale scores for dryness, pain, and fatigue. The secondary outcomes included the European League Against Rheumatism (EULAR) Sjögren's Syndrome Patient-reported Index (ESSPRI); the EULAR Sjögren's Syndrome Disease Activity Index; the Schirmer test score; unstimulated saliva flow; serum immunoglobulin G, A, and M concentrations; the Medical Outcome Study Short Form 36 score; salivary gland ultrasound imaging; and the Hospital Anxiety and Depression Scale score.

Results

The proportions of patients meeting the primary endpoint were 28.33% (17/60) in the acupuncture group and 31.66% (19/60) in the sham group, without a statistically significant difference (P = 0.705). The IgG concentration at week 16 and the homogeneity in ultrasonography of the salivary glands at week 8 showed significant differences between the 2 groups (P = 0.0490 and P = 0.0334, respectively). No other differences were observed between the 2 groups. ESSPRI and unstimulated saliva flow were improved in both groups compared to baseline, albeit with a significant difference between them.

Conclusion

In patients with primary Sjögren's syndrome, acupuncture did not satisfactorily improve symptoms compared to placebo. However, interesting discoveries and possible underlying reasons were demonstrated and discussed, which may be useful to studies in the future.

Clinical Trial Registration

[www.ClinicalTrials.gov], identifier [NCT02691377].

Hydroxychloroquine Therapy and Serum Immunoglobulin Levels in Women with IgG Subclass Deficiency and Systemic Lupus Erythematosus, Sjögren Syndrome, and Rheumatoid Arthritis: A Retrospective Study

Hydroxychloroquine (HCQ) therapy decreased immunoglobulin (Ig) levels in patients with Sjögren syndrome (SS) and rheumatoid arthritis (RA) in previous studies. We found no report of Ig levels of women with IgG subclass deficiency (IgGSD) and systemic lupus erythematosus (SLE), SS, or RA treated with HCQ. We retrospectively evaluated IgG, IgG subclass, IgA, and IgM levels and other characteristics of women at IgGSD diagnosis who did and did not take HCQ for SLE, SS, or RA. There were 132 women (48 subnormal IgG1 only, 49 combined subnormal IgG1/IgG3, and 35 subnormal IgG3 only). Mean age was 49 ± 13 years. Twenty-two women with SLE, SS, RA, or combination thereof reported HCQ ≥ 200 mg/day ≥ 6 months. In each IgGSD subtype, median Ig levels of women who took HCQ were not significantly lower than those of women who did not take HCQ. Women with combined subnormal IgG1/IgG3 who took HCQ had greater median IgG2 than women who did not take HCQ (4.89 g/L (range 4.43, 4.94) vs. 2.57 g/L (1.21, 6.44), respectively; p = 0.0123). Regressions on IgG1, IgG2, and IgG3 revealed positive associations with HCQ therapy (p = 0.0043, 0.0037, and 0.0139, respectively). There were no significant Ig associations with age, SLE, SS, or RA as independent variables. HCQ therapy of SLE, SS, or RA in women with IgGSD was not associated with significantly lower IgG, IgG subclass, IgA, or IgM levels. IgG1, IgG2, and IgG3 were positively associated with HCQ therapy, after adjustment for other variables.

Abnormal Changes of Monocyte Subsets in Patients With Sjögren’s Syndrome

Background

Recent studies have proven the existence of distinct monocyte subsets, which play a significant role in the development of some rheumatic diseases such as systemic lupus erythematosus (SLE). This study was performed to define the changes of monocyte subsets in patients with Sjögren’s Syndrome (SjS).

Methods

Single cell RNA-sequencing (scRNA-seq) data of monocytes from SjS patients and controls were analyzed. The transcriptomic changes in monocyte subsets between SjS and controls were identified and potential key functional pathways involved in SjS development were also explored.

Results

A total of 11 monocyte subsets were identified in the scRNA-seq analyses of monocytes. A new monocyte subset characterized by higher expression of VNN2 (GPI-80) and S100A12 (Monocyte cluster 3) was identified, and it was increased in SjS patients. Compared with controls, almost all monocyte subsets from SjS patients had increased expression of TNFSF10 (TRAIL). Moreover, interferon (IFN)-related and neutrophil activation-associated pathways were main up-regulated pathways in the monocytes of SjS patients.

Conclusion

This study uncovered the abnormal changes in monocyte subsets and their transcriptomic changes in SjS patients, and identified TNFSF10 ^high/+ monocytes as a potential key player in SjS pathogenesis and a promising target for SjS treatment.

Hyperresponsive cytosolic DNA-sensing pathway in monocytes from primary Sjögren's syndrome

Objectives

Cytosolic DNA-sensing pathway stimulation prompts type I IFN (IFN-I) production, but its role in systemic IFN-I pathway activation in primary SS (pSS) is poorly studied. Here we investigate the responsiveness of pSS monocytes and plasmacytoid dendritic cells (pDCs) to stimulator of interferon genes (STING) activation in relation to systemic IFN-I pathway activation and compare this with SLE.

Methods

Expression of DNA-sensing receptors cGAS, IFI16, ZBP-1 and DDX41, signalling molecules STING, TBK1 and IRF3, positive and negative STING regulators, and IFN-I-stimulated genes MxA, IFI44, IFI44L, IFIT1 and IFIT3 was analysed in whole blood, CD14⁺ monocytes, pDCs, and salivary glands by RT-PCR, monocyte RNA sequencing data, flow cytometry and immunohistochemical staining. Peripheral blood mononuclear cells (PBMCs) from pSS, SLE and healthy controls (HCs) were stimulated with STING agonist 2′3′-cGAMP. STING phosphorylation (pSTING) and intracellular IFNα were evaluated using flow cytometry.

Results

STING activation induced a significantly higher proportion of IFNα-producing monocytes, but not pDCs, in both IFN-low and IFN-high pSS compared with HC PBMCs. Additionally, a trend towards more pSTING⁺ monocytes was observed in pSS and SLE, most pronounced in IFN-high patients. Positive STING regulators TRIM38, TRIM56, USP18 and SENP7 were significantly higher expression in pSS than HC monocytes, while the dual-function STING regulator RNF26 was downregulated in pSS monocytes. STING was expressed in mononuclear infiltrates and ductal epithelium in pSS salivary glands. STING stimulation induced pSTING and IFNα in pSS and SLE pDCs.

Conclusion

pSS monocytes and pDCs are hyperresponsive to stimulation of the STING pathway, which was not restricted to patients with IFN-I pathway activation.

The interferon gene signature as a clinically relevant biomarker in autoimmune rheumatic disease

The interferon gene signature (IGS) is derived from the expression of interferon-regulated genes and is classically increased in response to type I interferon exposure. A raised whole blood IGS has increasingly been reported in rheumatic diseases as sequencing technology has advanced. Although its role remains unclear, we explore how a raised IGS can function as a clinically relevant biomarker, independent of whether it is a bystander effect or a key pathological process. For example, a raised IGS can act as a diagnostic biomarker when predicting rheumatoid arthritis in patients with arthralgia and anti-citrullinated protein antibodies, or predicting systemic lupus erythematous (SLE) in those with antinuclear antibodies; a theragnostic biomarker when predicting response for patients receiving disease modifying therapy, such as rituximab in rheumatoid arthritis; a biomarker of disease activity (early rheumatoid arthritis, dermatomyositis, systemic sclerosis, SLE); or finally a predictor of clinical characteristics, such as lupus nephritis in SLE or disease burden in primary Sjögren's syndrome. A high IGS does not uniformly predict worse clinical phenotypes across all diseases, as demonstrated by a reduced disease burden in primary Sjögren's syndrome, nor does it predict a universally poorer response to all therapies, as shown in rheumatoid arthritis. This dichotomy highlights both the complexity of type I interferon signalling in vivo and the current lack of standardisation when calculating the IGS. The IGS as a biomarker warrants further exploration, with beneficial clinical applications anticipated in multiple rheumatic diseases.

The Clinical and Immunological Activity Depending on the Presence of Interferon γ in Primary Sjögren’s Syndrome—A Pilot Study

The upregulation of IFN pathways and their stimulated genes is associated with primary Sjögren’s syndrome (pSS). The recent studies also indicate the involvement of interferon γ (IFNγ) in the pathogenesis of pSS. The study aimed to assess the clinical and immunological activity depending on the concentration of IFNγ in the peripheral blood in pSS patients. Methods: The study group consisted of patients over 18 years of age with a confirmed diagnosis of pSS. Based on the collected data, disease activity was assessed using the EULAR Sjögren’s syndrome disease activity index (ESSDAI) and the EULAR Sjögren’s syndrome patient reported index (ESSPRI). Results: Among 40 pSS patients, 33 (82%) showed increased levels of IFNγ. The group with positive IFNγ was younger (43 years) than the group with negative IFNγ (57 years) (p < 0.05). In the positive IFNγ group, the time to diagnosis was shorter (p < 0.05). There was a difference in ESSDAI among patients with and without IFNγ (p < 0.05). There were no differences between the groups in ESSPRI and the presence of cryoglobulins, specific anti-SSA, and anti-SSB antibodies and in C3 and C4 hypocomplementemia. RF occurred in both groups with a similar frequency (p = 0.6), but in patients with IFNγ presence, significantly higher RF titers were observed (34.9 vs. 10.5; p < 0.05). Conclusion: In the group of patients with positive IFNγ, the mean value of RF and ESSDAI was higher. This group was also younger than patients with pSS without IFNγ.

MyD88: At the heart of inflammatory signaling and cardiovascular disease

Cardiovascular disease is a leading cause of death worldwide and is associated with systemic inflammation. In depth study of the cell-specific signaling mechanisms mediating the inflammatory response is vital to improving anti-inflammatory therapies that reduce mortality and morbidity. Cellular damage in the cardiovascular system results in the release of damage associated molecular patterns (DAMPs), also known as "alarmins," which activate myeloid cells through the adaptor protein myeloid differentiation primary response 88 (MyD88). MyD88 is broadly expressed in most cell types of the immune and cardiovascular systems, and its role often differs in a cardiovascular disease context and cell specific manner. Herein we review what is known about MyD88 in the setting of a variety of cardiovascular diseases, discussing cell specific functions and the relative contributions of MyD88-dependent vs. independent alarmin triggered inflammatory signaling. The widespread involvement of these pathways in cardiovascular disease, and their largely unexplored complexity, sets the stage for future in depth mechanistic studies that may place MyD88 in both immune and non-immune cell types as an attractive target for therapeutic intervention in cardiovascular disease.

The Pathogenesis, Molecular Mechanisms, and Therapeutic Potential of the Interferon Pathway in Systemic Lupus Erythematosus and Other Autoimmune Diseases

Therapeutic success in treating patients with systemic lupus erythematosus (SLE) is limited by the multivariate disease etiology, multi-organ presentation, systemic involvement, and complex immunopathogenesis. Agents targeting B-cell differentiation and survival are not efficacious for all patients, indicating a need to target other inflammatory mediators. One such target is the type I interferon pathway. Type I interferons upregulate interferon gene signatures and mediate critical antiviral responses. Dysregulated type I interferon signaling is detectable in many patients with SLE and other autoimmune diseases, and the extent of this dysregulation is associated with disease severity, making type I interferons therapeutically tangible targets. The recent approval of the type I interferon-blocking antibody, anifrolumab, by the US Food and Drug Administration for the treatment of patients with SLE demonstrates the value of targeting this pathway. Nevertheless, the interferon pathway has pleiotropic biology, with multiple cellular targets and signaling components that are incompletely understood. Deconvoluting the complexity of the type I interferon pathway and its intersection with lupus disease pathology will be valuable for further development of targeted SLE therapeutics. This review summarizes the immune mediators of the interferon pathway, its association with disease pathogenesis, and therapeutic modalities targeting the dysregulated interferon pathway.

Serum IFNα2 measured by single-molecule array associates with systemic disease manifestations in Sjögren's syndrome

Objectives

Type I IFN (IFN-I) activation is a prominent feature of primary SS (pSS), SLE and SSc. Ultrasensitive single-molecule array (Simoa) technology has facilitated the measurement of subfemtomolar concentrations of IFNs. Here we aimed to measure IFN-α2 in serum from pSS, SLE and SSc using a Simoa immunoassay and correlate these levels to blood IFN-stimulated gene (ISG) expression and disease activity.

Methods

Serum IFN-α2 was measured in patients with pSS (n = 85 and n = 110), SLE (n = 24) and SSc (n = 23) and healthy controls (HCs; n = 68) using an IFN-α Simoa assay on an HD-X analyser. IFN-I pathway activation was additionally determined from serum by an IFN-I reporter assay and paired samples of whole blood ISG expression of IFI44, IFI44L, IFIT1, IFIT3 and MxA by RT-PCR or myxovirus resistance protein 1 (MxA) protein ELISA.

Results

Serum IFN-α2 levels were elevated in pSS (median 61.3 fg/ml) compared with HCs (median ≤5 fg/ml, P < 0.001) and SSc (median 11.6 fg/ml, P = 0.043), lower compared with SLE (median 313.5 fg/ml, P = 0.068) and positively correlated with blood ISG expression (r = 0.66–0.94, P < 0.001). Comparable to MxA ELISA [area under the curve (AUC) 0.93], IFN-α2 measurement using Simoa identified pSS with high ISG expression (AUC 0.90) with 80–93% specificity and 71–84% sensitivity. Blinded validation in an independent pSS cohort yielded a comparable accuracy. Multiple regression indicated independent associations of autoantibodies, IgG, HCQ treatment, cutaneous disease and a history of extraglandular manifestations with serum IFN-α2 concentrations in pSS.

Conclusion

Simoa serum IFN-α2 reflects blood ISG expression in pSS, SLE and SSc. In light of IFN-targeting treatments, Simoa could potentially be applied for patient stratification or retrospective analysis of historical cohorts.

Comparative analysis of the efficacy and safety of herbal decoction CheReCunJin alone and combined with hydroxychloroquine for treating primary Sjögren's syndrome: A randomized controlled trial

INTRODUCTION

There is currently no established effective treatment for primary Sjögren's syndrome (pSS). Traditional Chinese Medicine (TCM) is widely used in China and is reported to improve patient symptoms. This study compare the clinical efficacy and safety of herbal decoction CheReCunJin alone and combined with hydroxychloroquine for the treatment of pSS.

METHODS

Seventy pSS patients without visceral involvement were randomly assigned in equal numbers to oral administration of CheReCunJin decoction only (group 1) or CheReCunJin decoction combined with hydroxychloroquine (group 2), Efficacy was evaluated after 3 months of treatment by the TCM syndrome and total effectiveness scores, European League Against Rheumatism (EULAR) Sjögren's Syndrome Patient Reported Index (ESSPRI), and Sjögren's Syndrome Disease Activity Index (ESSDAI), Schirmer's test, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and immunoglobulin G (IgG) levels. Safety was assessed.

RESULTS

There were no differences in the baseline characteristics of the two groups. Compared with baseline values, the TCM syndrome, ESSPRI and ESSDAI scores, ESR, CRP, and Schirmer's test results improved significantly in both groups after treatment (p < 0.05). There was no significant difference in the TCM syndrome total effectiveness rate between the two groups (p = 0.31). Between-group differences in the changes in ESSPRI, ESSDAI, ESR, CRP, Schirmer's test, and IgG after treatment were not significant (all p> 0.05). Adverse reactions were reported in 5.88% of group 1 and 3.33% of group 2 participants (p = 0.83).

CONCLUSION

CheReCunJin decoction alone was effective and safe for the treatment of pSS.

TRIAL REGISTRATION

Chinese Clinical Trial Registry: ChiCTR1800016471.

Factors associated with IgG levels in adults with IgG subclass deficiency

Background

Factors associated with IgG levels in adults with IgG subclass deficiency (IgGSD) are incompletely understood. We studied adults with IgGSD with subnormal IgG1 only, subnormal IgG1/IgG3, or subnormal IgG3 only without other subnormal IgG subclasses, IgA, or IgM. We compiled: age; sex; autoimmune condition(s) (AC); atopy; IgG, IgG subclasses, IgA, IgM; IgGsum (IgG1 + IgG2 + IgG3 + IgG4); and D (percentage difference between IgGsum and IgG). We compared attributes of patients with/without subnormal IgG (< 7.00 g/L; subnormal IgG1 subclass groups only) and analyzed IgGsum and IgG relationships. We performed backward stepwise regressions on IgG using independent variables IgG subclasses, age, and sex and on D using independent variables age and sex.

Results

There were 39 patients with subnormal IgG1 only (89.7% women), 53 with subnormal IgG1/IgG3 (88.7% women), and 115 with subnormal IgG3 only (91.3% women). Fifteen patients (38.5%) and 32 patients (60.4%) in the respective subnormal IgG1 subclass groups had subnormal IgG. Attributes of patients with/without IgG < 7.00 g/L were similar, except that AC prevalence was lower in patients with subnormal IgG1 only and IgG < 7.00 g/L than ≥ 7.00 g/L (p = 0.0484). Mean/median IgG1 and IgG2 were significantly lower in patients with IgG < 7.00 g/L in both subnormal IgG1 subclass groups (p < 0.0001, all comparisons). Regressions on IgG in three subclass groups revealed positive associations with IgG1 and IgG2 (p < 0.0001 each association). Regressions on D revealed no significant association. IgG1 percentages of IgGsum were lower and IgG2 percentages were higher in patients with subnormal IgG1 subclass levels than subnormal IgG3 only (p < 0.0001 all comparisons).

Conclusions

We conclude that both IgG1 and IgG2 are major determinants of IgG in patients with subnormal IgG1, combined subnormal IgG1/IgG3, or subnormal IgG3 and that in patients with subnormal IgG1 or combined subnormal IgG1/IgG3, median IgG2 levels are significantly lower in those with IgG < 7.00 g/L than those with IgG ≥ 7.00 g/L.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12865-021-00447-3.

Association between increased Bcl-2, Fas and FasL levels and inflammation extent in labial salivary glands during primary Sjögren's syndrome

BACKGROUND

Primary Sjögren syndrome (pSS) is a chronic autoimmune disease characterized by epithelial atrophy, mononuclear infiltration in exocrine glands resulting in defective function of these glands. In pSS, atrophy of the epithelium is caused by an increased amount of apoptosis.

OBJECTIVE

The main aim of this study is to investigate the role of the apoptosis-related factors by studying Bcl-2, Fas and FasL expression in relation to the extent of inflammation as well as the effect of therapy on the expression of these mediators.

METHODS

In pSS patients (n=62) documented for their serological and clinical features, Fas, FasL and Bcl-2 plasma levels were assessed using enzyme-linked immunosorbent assays. In the same context, we investigated their expression by immunohistochemistry analysis in the labial salivary glands samples in association with the extent of inflammation.

RESULTS

Interestingly, our results indicated that in pSS patients, the plasmatic Bcl-2, Fas and FasL levels, which appear to be associated with the severity of inflammation and were significantly elevated in comparison to the healthy controls. Moreover, a significant decrease in all these factors was observed in patients after combined corticosteroids-hydroxychloroquine therapy. Importantly, we report a strong positive correlation between Bcl-2 and NO levels. The immunohistochemical staining reveals a strong Bcl-2 expression in infiltrating mononuclear cells and a total absence in the acinar cells. The Bcl-2 level varies according to the severity of the pathology. However, the expression of Fas and FasL was less important and predominantly localized in infiltrating mononuclear cells.

CONCLUSION

Our current study highlights the involvement of Bcl-2, Fas and FasL in pSS glands injury. These factors may act as useful predictor markers of a clinical course in pSS suggesting a novel approach in the pSS patients monitoring.

Current and future therapies for primary Sjögren syndrome

Primary Sjögren syndrome (pSS) is a systemic autoimmune disease that is characterized by a triad of symptoms that affect all patients (dryness, pain and fatigue). In addition, systemic involvement can affect between one-third and one-half of patients. The management of patients with pSS has been negatively affected by a lack of effective treatments; however, knowledge of the epidemiology of pSS has increased, and advances in developing classification criteria, systemic disease activity scoring and patient-reported outcomes have been made during the past decade. Progress has also been made in understanding the mechanisms that underlie the pathogenesis of pSS, which has enabled a more targeted therapeutic approach to be taken. At present, therapeutic decisions rely on the evaluation of symptoms and systemic manifestations and are mostly formed on the basis of experience rather than evidence, and on similarities with other autoimmune diseases, although the 2019 management recommendations from EULAR are now being used to inform clinical management of pSS. This Review summarizes the available evidence for systemic treatments for pSS and includes discussions of advances in outcome assessment, the current evidence for DMARD use and an overview of promising future therapeutics.

DNA Methylation-Based Interferon Scores Associate With Sub-Phenotypes in Primary Sjögren's Syndrome

Primary Sjögren’s syndrome (pSS) is an autoimmune inflammatory disease with profound clinical heterogeneity, where excessive activation of the type I interferon (IFN) system is considered one of the key mechanisms in disease pathogenesis. Here we present a DNA methylation-based IFN system activation score (DNAm IFN score) and investigate its potential associations with sub-phenotypes of pSS. The study comprised 100 Swedish patients with pSS and 587 Swedish controls. For replication, 48 patients with pSS from Stavanger, Norway, were included. IFN scores were calculated from DNA methylation levels at the IFN-induced genes RSAD2, IFIT1 and IFI44L. A high DNAm IFN score, defined as > mean_controls +2SD_controls (IFN score >4.4), was observed in 59% of pSS patients and in 4% of controls (p=1.3x10^-35). Patients with a high DNAm IFN score were on average seven years younger at symptom onset (p=0.017) and at diagnosis (p=3x10^-3). The DNAm IFN score levels were significantly higher in pSS positive for both SSA and SSB antibodies compared to SSA/SSB negative patients (p_discovery=1.9x10^-8, p_replication=7.8x10^-4). In patients positive for both SSA subtypes Ro52 and Ro60, an increased score was identified compared to single positive patients (p=0.022). Analyzing the discovery and replication cohorts together, elevated DNAm IFN scores were observed in pSS with hypergammaglobulinemia (p=2x10^-8) and low C4 (p=1.5x10^-3) compared to patients without these manifestations. Patients < 70 years with ongoing lymphoma at DNA sampling or lymphoma at follow-up (n=7), presented an increased DNAm IFN score compared to pSS without lymphoma (p=0.025). In conclusion, the DNAm-based IFN score is a promising alternative to mRNA-based scores for identification of patients with activation of the IFN system and may be applied for patient stratification guiding treatment decisions, monitoring and inclusion in clinical trials.

Revisiting the JOQUER trial: stratification of primary Sjögren's syndrome and the clinical and interferon response to hydroxychloroquine

To re-analyse the clinical outcomes and interferon (IFN) activity data from the JOQUER trial, a phase III trial investigating hydroxychloroquine (HCQ) in patients with primary Sjögren’s syndrome (pSS), after stratifying patients into putative pathobiological subgroups utilizing the Newcastle Sjögren’s Stratification Tool (NSST) based on patient-reported symptoms of dryness, pain, fatigue, anxiety and depression. 107 patients were assigned to one of four subgroups using NSST at baseline—the high symptom burden (HSB), pain dominant with fatigue (PDF), dryness dominant with fatigue (DDF) and low symptom burden (LSB). Endpoints were re-analysed after stratification, testing for treatment differences within subgroups and adjusting for baseline differences using a repeated measures covariate model. The HSB subgroup (n = 32) showed a relative improvement in ESSPRI of 1.49 points (95% CI 0.54–2.43; p = 0.002) within 12 weeks in patients taking HCQ compared to placebo, with no further changes after 24 weeks. For the LSB subgroup (n = 14), the ESSPRI worsened in the placebo but not the HCQ arm after 12 weeks (mean difference 1.44, 95% CI 0.05–2.83, p = 0.042). Neither the HSB nor the LSB patients showed significant changes in IFN activity at 24 weeks. There were no significant differences in ESSPRI in the PDF (n = 39) and DDF (n = 22) patients taking HCQ. However, significant reductions in overall IFN score at 24 weeks were seen in both PDF (difference at 24 weeks; 6.41, 95% CI, 2.48–10.34, p = 0.002) and DDF (difference at 24 weeks; 7.23, 95% CI, 1.85–12.6, p = 0.009) without improvement in ESSPRI. Although the JOQUER trial reported no overall benefit from HCQ in pSS patients, stratification suggests that both HSB and LSB subgroups may respond to HCQ. However, these patients may benefit through mechanisms other than the reduction of IFN activities.

Type I Interferons in the Pathogenesis and Treatment of Autoimmune Diseases

Type I interferons (IFN-Is) are a very important group of cytokines that are produced by innate immune cells but also act on adaptive immune cells. IFN-Is possess antiviral, antitumor, and anti-proliferative effects, as well are associated with the initiation and maintenance of autoimmune disorders. Studies have shown that aberrantly expressed IFN-Is and/or type I IFN-inducible gene signatures in the serum or tissues of patients with autoimmune disorders are linked to their pathogenesis, clinical manifestations, and disease activity. Type I interferonopathies with mutations in genes impacting the type I IFN signaling pathway have shown symptoms and characteristics similar to those of systemic lupus erythematosus (SLE). Furthermore, both interventions in animal models and clinical trials of therapies targeting the type I IFN signaling pathway have shown efficacy in the treatment of autoimmune diseases. Our review aims to summarize the functions and targeted therapies (as well as clinical trials) of IFN-Is in both adult and pediatric autoimmune diseases, such as SLE, pediatric SLE (pSLE), rheumatoid arthritis (RA), juvenile idiopathic arthritis (JIA), juvenile dermatomyositis (JDM), Sjögren syndrome (SjS), and systemic sclerosis (SSc), discussing the potential abnormal regulation of transcription factors and epigenetic modifications and providing a potential mechanism for pathogenesis and therapeutic strategies for future clinical use.

Effectiveness and Safety of Iguratimod in Treating Primary Sjögren's Syndrome: A Systematic Review and Meta-Analysis

Objectives: We aimed to assess the effectiveness and safety of iguratimod (IGU) in treating primary Sjögren’s syndrome (pSS) by meta-analysis.

Methods: Eight databases and two clinical trial websites were searched from conception to August 10, 2020, for relevant randomized controlled trials (RCTs) on outcomes of patients with pSS treated with IGU. Revman 5.4 was used for statistical analysis and creating plots.

Results: A total of 1,384 patients with pSS from 19 RCTs were included in this meta-analysis. Pooled results demonstrated that patients treated with IGU + hydroxychloroquine (HCQ) + glucocorticoid (GC) showed significant differences in erythrocyte sedimentation rate (ESR), rheumatoid factor (RF) level, platelet (PLT) count, immunoglobulin G (IgG) level, salivary flow rate, Schirmer’s test result, EULAR Sjögren’s Syndrome Patient Reported Index (ESSPRI), EULAR Sjögren’s Syndrome Disease Activity Index (ESSDAI), and efficacy rate (p ≤ 0.01) compared to patients treated with HCQ + GC. Compared to treatment with HCQ and GC, co-administration of IGU with GC showed significant differences in ESR and RF level (p ≤ 0.01); however, no significant differences were noted in IgG level. Conversely, the IgG level showed a significant improvement in the IGU + HCQ + GC group compared to the HCQ + GC group. The results of safety analysis revealed that seven trials showed no significant differences in adverse events (AEs) between the IGU + HCQ + GC and HCQ + GC groups (p = 0.15). Although no severe AEs were noted, gastrointestinal discomfort was the most common AE in the IGU group. No significant differences in AEs were observed between the IGU + GC and HCQ + GC groups.

Conclusion: IGU improved the clinical symptoms of patients with pSS, including inflammatory indicators (ESR, IgG, and RF levels), PLT count, secretion function of the salivary and lacrimal glands (salivary flow rate and Schirmer’s test result), and disease indexes (ESSDAI and ESSPRI), when co-administered with HCQ + GC therapy without increasing the risks of AEs. Therefore, IGU can be considered as an effective and safe drug for clinical therapy of pSS. Considering the limitations of the present trials, more long-term, multicenter, and high-quality RCTs are required to assess the effectiveness and safety of IGU for treating patients with pSS.

Hydroxychloroquine Effects on TLR Signalling: Underexposed but Unneglectable in COVID-19

The main basis for hydroxychloroquine (HCQ) treatment in COVID-19 is the compound's ability to inhibit viral replication in vitro. HCQ also suppresses immunity, mainly by interference in TLR signalling, but reliable clinical data on the extent and nature of HCQ-induced immunosuppression are lacking. Here, we discuss the mechanistic basis for the use of HCQ against SARS-CoV-2 in a prophylactic setting and in a therapeutic setting, at different stages of the disease. We argue that the clinical effect of prophylactic or therapeutic HCQ treatment in COVID-19 depends on the balance between inhibition of viral replication, immunosuppression, and off-target side effects, and that the outcome is probably dependent on disease stage and disease severity. This is supported by the initial outcomes of the well-designed randomized controlled trials: so far, evidence for a beneficial effect of HCQ treatment for COVID-19 is weak and conflicting.

Interleukin 6 receptor inhibition in primary Sjögren syndrome: a multicentre double-blind randomised placebo-controlled trial

OBJECTIVES

No immunomodulatory drug has been approved for primary Sjögren's syndrome, a systemic autoimmune disease affecting 0.1% of the population. To demonstrate the efficacy of targeting interleukin 6 receptor in patients with Sjögren's syndrome-related systemic complications.

METHODS

Multicentre double-blind randomised placebo-controlled trial between 24 July 2013 and 16 July 2018, with a follow-up of 44 weeks, involving 17 referral centres. Inclusion criteria were primary Sjögren's syndrome according to American European Consensus Group criteria and score ≥5 for the EULAR Sjögren's Syndrome Disease activity Index (ESSDAI, score of systemic complications). Patients were randomised to receive either 6 monthly infusions of tocilizumab or placebo. The primary endpoint was response to treatment at week 24. Response to treatment was defined by the combination of (1) a decrease of at least 3 points in the ESSDAI, (2) no occurrence of moderate or severe activity in any new domain of the ESSDAI and (3) lack of worsening in physician's global assessment on a Visual Numeric Scale ≥1/10, all as compared with enrolment.

RESULTS

110 patients were randomised, 55 patients to tocilizumab (mean (SD) age: 50.9 (12.4) years; women: 98.2%) and 55 patients to placebo (54.8 (10.7) years; 90.9%). At 24 weeks, the proportion of patients meeting the primary endpoint was 52.7% (29/55) in the tocilizumab group and 63.6% (35/55) in the placebo group, for a difference of -11.4% (95% credible interval -30.6 to 9.0) (Pr[Toc >Pla]=0.14).

CONCLUSION

Among patients with primary Sjögren's syndrome, the use of tocilizumab did not improve systemic involvement and symptoms over 24 weeks of treatment compared with placebo.

TRIAL REGISTRATION NUMBER

NCT01782235.

Improvement of Severe Fatigue Following Nuclease Therapy in Patients With Primary Sjögren's Syndrome: A Randomized Clinical Trial

OBJECTIVE

To assess the safety and efficacy of RSLV-132, an RNase Fc fusion protein, in a phase II randomized, double-blind, placebo-controlled clinical trial in patients with primary Sjögren's syndrome (SS).

METHODS

Thirty patients with primary SS were randomized to receive treatment with RSLV-132 or placebo intravenously once per week for 2 weeks, and then every 2 weeks for 12 weeks. Eight patients received placebo and 20 patients received RSLV-132 at a dose of 10 mg/kg. Clinical efficacy measures included the European League Against Rheumatism (EULAR) Sjögren's Syndrome Disease Activity Index, EULAR Sjögren's Syndrome Patient Reported Index (ESSPRI), Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-F), Profile of Fatigue (ProF), and the Digit Symbol Substitution Test (DSST).

RESULTS

Patients randomized to receive RSLV-132 experienced clinically meaningful improvements in the ESSPRI score (P = 0.27), FACIT-F score (P = 0.05), ProF score (P = 0.07), and DSST (P = 0.02) from baseline to day 99, whereas patients who received placebo showed no changes in any of these clinical efficacy measures. This improvement was significantly correlated with increased expression of selected interferon-inducible genes (Pearson's correlations, each P < 0.05).

CONCLUSION

Administration of RSLV-132 improved severe fatigue, as determined by 4 independent patient-reported measures of fatigue, in patients with primary SS.

Can endolysosomal deacidification and inhibition of autophagy prevent severe COVID-19?

The possibility is examined that immunomodulatory pharmacotherapy may be clinically useful in managing the pandemic coronavirus disease 2019 (COVID-19), known to result from infection by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a positive-sense single-stranded RNA virus. The dominant route of cell entry of the coronavirus is via phagocytosis, with ensconcement in endosomes thereafter proceeding via the endosomal pathway, involving transfer from early (EEs) to late endosomes (LEs) and ultimately into lysosomes via endolysosomal fusion. EE to LE transportation is a rate-limiting step for coronaviruses. Hence inhibition or dysregulation of endosomal trafficking could potentially inhibit SARS-CoV-2 replication. Furthermore, the acidic luminal pH of the endolysosomal system is critical for the activity of numerous pH-sensitive hydrolytic enzymes. Golgi sub-compartments and Golgi-derived secretory vesicles also depend on being mildly acidic for optimal function and structure. Activation of endosomal toll-like receptors by viral RNA can upregulate inflammatory mediators and contribute to a systemic inflammatory cytokine storm, associated with a worsened clinical outcome in COVID-19. Such endosomal toll-like receptors could be inhibited by the use of pharmacological agents which increase endosomal pH, thereby reducing the activity of acid-dependent endosomal proteases required for their activity and/or assembly, leading to suppression of antigen-presenting cell activity, decreased autoantibody secretion, decreased nuclear factor-kappa B activity and decreased pro-inflammatory cytokine production. It is also noteworthy that SARS-CoV-2 inhibits autophagy, predisposing infected cells to apoptosis. It is therefore also suggested that further pharmacological inhibition of autophagy might encourage the apoptotic clearance of SARS-CoV-2-infected cells.

Oral disease-modifying antirheumatic drugs and immunosuppressants with antiviral potential, including SARS-CoV-2 infection: a review

There have been several episodes of viral infection evolving into epidemics in recent decades, and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the latest example. Its high infectivity and moderate mortality have resulted in an urgent need to find an effective treatment modality. Although the category of immunosuppressive drugs usually poses a risk of infection due to interference of the immune system, some of them have been found to exert antiviral properties and are already used in daily practice. Recently, hydroxychloroquine and baricitinib have been proposed as potential drugs for SARS-CoV-2. In fact, there are other immunosuppressants known with antiviral activities, including cyclosporine A, hydroxyurea, minocycline, mycophenolic acid, mycophenolate mofetil, leflunomide, tofacitinib, and thalidomide. The inherent antiviral activity could be a treatment choice for patients with coexisting rheumatological disorders and infections. Clinical evidence, their possible mode of actions and spectrum of antiviral activities are included in this review article.

LAY SUMMARY

Immunosuppressants often raise the concern of infection risks, especially for patients with underlying immune disorders. However, some disease-modifying antirheumatic drugs (DMARDs) with inherent antiviral activity would be a reasonable choice in the situation of concomitant viral infections and flare up of autoimmune diseases. This review covers DMARDs of treatment potential for SARS-CoV-2 in part I, and antiviral mechanisms plus trial evidence for viruses other than SARS-CoV-2 in part II.

Chinese herbal medicine SS-1 inhibits T cell activation and abrogates TH responses in Sjögren's syndrome

BACKGROUND/PURPOSE

Sjögren's syndrome (SS) is an autoimmune disease and its conventional treatment has exhibited limited therapeutic efficacy. Traditional Chinese medicine has been demonstrated to ameliorate the sicca symptoms of SS by decreasing the level of T_H1 and T_H2 cytokines and increasing salivary flow rate. A newly designed traditional Chinese medicine, SS-1, showed improved efficacy in alleviating the dryness symptoms of SS patients in the National Taiwan SS cohort investigation. Here, we investigated the effect of SS-1 on T cell responses.

METHODS

SS-1 was authenticated and its major compounds were verified by high-performance liquid chromatography. We examined the effects of SS-1 on the activation and T_H1, T_H2, and T_H17 polarization of murine T cells. We also determined the level of T_H1, T_H2, and T_H17 cytokine RNA in peripheral blood mononuclear cells of SS patients before and after SS-1 treatment.

RESULTS

SS-1 treatment inhibits the activation and T_H1, T_H2, and IL-17A⁺IFNγ⁺ T_H polarization of murine T cells. SS-1 treatment also significantly reduces IFN-γ, IL-4, and IL-13 expression, and moderately reduces IL-17A expression in peripheral blood mononuclear cells of SS patients.

CONCLUSION

Our results suggest that SS-1 inhibits T cell activation and diminishes T_H1, T_H2, and IL-17⁺IFN-γ⁺ T_H responses in SS patients.

Update on disease pathogenesis, diagnosis, and management of primary Sjögren's syndrome

Primary Sjögren's syndrome (pSS) is a typical multisystem disease, characterized by lymphocytic infiltration of the exocrine glands leading to glandular dysfunction. Multiple systemic manifestations occur in those of serious conditions, with different courses and outcomes. Its pathogenesis is complex, and its diagnosis and management are being constantly updated and improved. We have failed to have much progress in targeted immunotherapy for pSS, and as yet this is still based on empirical treatment. Many studies have tried to define pSS more accurately, to study its pathogenesis, to find effective treatment strategies, opening up new avenues for early diagnosis and precise management of pSS.

Equal rights in autoimmunity: is Sjögren’s syndrome ever ‘secondary’?

Sjögren’s syndrome (SjS) accompanied by other systemic autoimmune rheumatic connective tissue diseases has historically been termed ‘secondary’ in contrast to ‘primary’ SjS as a standalone entity. However, it is a matter of a long-standing debate whether the prefixes ‘primary’ and ‘secondary’, including a temporal component, are obsolete in the terminology of SjS. We review the history and the pathophysiological, chronological, genetic, histological and clinical data underlying the concept of ‘secondary’ SjS. There are important unintended consequences of the nomenclature; notably ‘secondary’ SjS has been much less researched and is often excluded from clinical trials. We argue for further research, a change in terminology and more stringent classification. Further we highlight possible opportunities for trials in SjS and other systemic autoimmune diseases that might contribute to an advance in care for all patients with SjS.

IMMUNOINFLAMMATORY RHEUMATIC DISEASES ASSOCIATED WITH TYPE I INTERFERON: NEW EVIDENCE

Immunoinflammatory rheumatic diseases (IIRDs) are a large group of pathological conditions with impaired immunological tolerance to autogenous tissues, leading to inflammation and irreversible organ damage. The review discusses current ideas on the role of type I interferons in the immunopathogenesis of IIRDs, primarily systemic lupus erythematosus, and new possibilities for personalized therapy.