Necrotic cell death increases the release of macrophage migration inhibitory factor by monocytes/macrophages

Macrophage migration inhibitory factor (MIF) is a pleiotropic inflammatory molecule with both cytokine and noncytokine activity. MIF is constitutively released from multiple cell types via an unconventional secretory pathway that is not well defined. Here, we looked at MIF release from human and mouse monocytes/macrophages in response to different stimuli. While MIF release was not significantly altered in response to lipopolysaccharide or heat-killed Escherichia coli, cytotoxic stimuli strongly promoted release of MIF. MIF release was highly upregulated in cells undergoing necrosis, necroptosis and NLRP3 inflammasome-dependent pyroptosis. Our data suggest that cell death represents a major route for MIF release from myeloid cells. The functional significance of these findings and their potential importance in the context of autoimmune and inflammatory diseases warrant further investigation.

Utility of repeated antinuclear antibody tests: a retrospective database study

BACKGROUND

Anti-nuclear antibody (ANA) testing is frequently used as a diagnostic or screening test in patients with inflammatory or musculoskeletal symptoms. The value of repeat testing is unclear. We sought to evaluate the frequency, utility, and cost of repeat ANA testing. The main objective was to assess the positive predictive value of a repeat ANA test for the diagnosis of rheumatological conditions associated with ANA.

METHODS

In this retrospective cohort study, we analysed data from a single, multisite tertiary health network in Australia across a 7-year period. ANA and other autoimmune test results were obtained from the hospital pathology system with a positive ANA titre cutoff set at 1:160. Clinical information was sourced from clinical information systems on any patient who had a change in ANA result from negative to positive on repeat testing. The cost of repeated ANA testing was calculated using the Australian Government Medicare Benefits Schedule.

FINDINGS

From March 19, 2011, to July 23, 2018, a total of 36 715 ANA tests were done in 28 840 patients at a total cost of US$675 029 (2018 equivalent). 14 058 (38·3%) of these ANA tests were positive. 7875 (21·4%) of the ordered tests were repeats in 4887 (16·9%) of the patients, among whom 2683 (54·9%) had initially negative tests, and 2204 (45·1%) had initially positive tests. 511 (19·0%) of the 2683 patients with initially negative tests had a positive result on at least one repeat test, with a median time to first positive result of 1·74 years (IQR 0·54-3·60). A change from negative to positive ANA was associated with a new diagnosis in only five (1·1%) of the 451 patients with clinical information available and no previous diagnosis of an ANA-associated rheumatological condition, yielding a positive predictive value of 1·1% (95% CI 0·4-2·7).

INTERPRETATION

Repeat ANA testing after a negative result has low utility and results in high cost.

FUNDING

Monash Health.

Glucocorticoid-induced leucine zipper modulates macrophage polarization and apoptotic cell clearance

Macrophages are professional phagocytes that display remarkable plasticity, with a range of phenotypes that can be broadly characterized by the M1/M2 dichotomy. Glucocorticoid (GC)-induced leucine zipper (GILZ) is a protein known to mediate anti-inflammatory and some pro-resolving actions, including as neutrophil apoptosis. However, the role of GILZ in key macrophage function is not well understood. Here, we investigated the role of GILZ on macrophage reprogramming and efferocytosis. Using murine bone-marrow-derived macrophages (BMDMs), we found that GILZ was expressed in naive BMDMs and exhibited increased expression in M2-like macrophages (IL4-differentiated). M1-like macrophages (IFN/LPS-differentiated) from GILZ^-/- mice showed higher expression of the M1 markers CD86, MHC class II, iNOS, IL-6 and TNF-α, associated with increased levels of phosphorylated STAT1 and lower IL-10 levels, compared to M1-differentiated cells from WT mice. There were no changes in the M2 markers CD206 and arginase-1 in macrophages from GILZ^-/- mice differentiated with IL-4, compared to cells from WT animals. Treatment of M1-like macrophages with TAT-GILZ, a cell-permeable GILZ fusion protein, decreased the levels of CD86 and MHC class II in M1-like macrophages without modifying CD206 levels in M2-like macrophages. In line with the in vitro data, increased numbers of M1-like macrophages were found into the pleural cavity of GILZ^-/- mice after LPS-injection, compared to WT mice. Moreover, efferocytosis was defective in the context of GILZ deficiency, both in vitro and in vivo. Conversely, treatment of LPS-injected mice with TAT-GILZ promoted inflammation resolution, associated with lower numbers of M1-like macrophages and increased efferocytosis. Collectively, these data indicate that GILZ is a regulator of important macrophage functions, contributing to macrophage reprogramming and efferocytosis, both key steps for the resolution of inflammation.

Laboratory investigation results influence Physician’s Global Assessment (PGA) of disease activity in SLE

Objective

To evaluate the impact of laboratory results on scoring of the Physician Global Assessment (PGA) of disease activity in systemic lupus erythematosus.

Methods

Fifty clinical vignettes were presented via an online survey to a group of international lupus experts. For each case, respondents scored the PGA pre and post knowledge of laboratory test results (pre-lab and post-lab PGAs). Agreement between individual assessors and relationships between pre-lab and post-lab PGAs, and PGAs and Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K) were determined. Respondents were also asked about factors they incorporate into their PGA determinations.

Results

Sixty surveys were completed. The inter-rater PGA reliability was excellent (pre-lab intraclass correlation coefficient (ICC) 0.98; post-lab ICC 0.99). Post-lab PGAs were higher than pre-lab PGAs: median (IQR) pre-lab PGA 0.5 (1.05), post-lab PGA 1 (1.3) (p<0.001), with a median (IQR) difference of 0.2 (0.45). In general, all abnormal labs including elevated anti-double stranded DNA antibody level (dsDNA) and low complement impacted PGA assessment. Cases with weakest correlations between pre-lab and post-lab PGA were characterised by laboratory results revealing nephritis and/or haematological manifestations. Both pre-lab and post-lab PGAs correlated with SLEDAI-2K. However, a significantly stronger correlation was observed between post-lab PGA and SLEDAI-2K. Multiple factors influenced PGA determinations. Some factors were considered by an overwhelming majority of lupus experts, with less agreement on others.

Conclusions

We found excellent inter-rater reliability for PGAs in a group of international lupus experts. Post-lab PGA scores were higher than pre-lab PGA scores, with a significantly stronger correlation with the SLEDAI-2K. Our findings indicate that PGA scoring should be performed with knowledge of pertinent laboratory results.

Plasmacytoid dendritic cells from parent strains of the NZB/W F1 lupus mouse contribute different characteristics to autoimmune propensity

The NZB/W F1 (F1) mice develop severe disease that is similar to human systemic lupus erythematosus. By contrast, each parent strain, NZB or NZW, has limited autoimmunity, suggesting traits of both strains contribute to pathogenesis. Although many of the contributing genes have been identified, the contributing cellular abnormality associated with each parent strain remains unresolved. Given that plasmacytoid dendritic cells (pDCs) are key to the pathogenesis of lupus, we investigated the properties of pDCs from NZB and NZW mice. We found that NZB mouse had higher numbers of pDCs, with much of the increase being contributed by a more abundant CD8⁺ pDC subset. This was associated with prolonged survival and stronger proliferation of CD4⁺ T cells. By contrast, NZW pDCs had heightened capacity to produce interferon-α (IFNα) and IFNλ, and promoted stronger B-cell proliferation upon CpG stimulation. Thus, our data reveal the different functional and numerical characteristics of pDCs from NZW and NZB mouse.

Connexin-Dependent Transfer of cGAMP to Phagocytes Modulates Antiviral Responses

Activation of cyclic GMP-AMP (cGAMP) synthase (cGAS) plays a critical role in antiviral responses to many DNA viruses. Sensing of cytosolic DNA by cGAS results in synthesis of the endogenous second messenger cGAMP that activates stimulator of interferon genes (STING) in infected cells. Critically, cGAMP can also propagate antiviral responses to uninfected cells through intercellular transfer, although the modalities of this transfer between epithelial and immune cells remain poorly defined. We demonstrate here that cGAMP-producing epithelial cells can transactivate STING in cocultured macrophages through direct cGAMP transfer. cGAMP transfer was reliant upon connexin expression by epithelial cells and pharmacological inhibition of connexins blunted STING-dependent transactivation of the macrophage compartment. Macrophage transactivation by cGAMP contributed to a positive-feedback loop amplifying antiviral responses, significantly protecting uninfected epithelial cells against viral infection. Collectively, our findings constitute the first direct evidence of a connexin-dependent cGAMP transfer to macrophages by epithelial cells, to amplify antiviral responses.IMPORTANCE Recent studies suggest that extracellular cGAMP can be taken up by macrophages to engage STING through several mechanisms. Our work demonstrates that connexin-dependent communication between epithelial cells and macrophages plays a significant role in the amplification of antiviral responses mediated by cGAMP and suggests that pharmacological strategies aimed at modulating connexins may have therapeutic applications to control antiviral responses in humans.

Trial of Anifrolumab in Active Systemic Lupus Erythematosus

BACKGROUND

Anifrolumab, a human monoclonal antibody to type I interferon receptor subunit 1 investigated for the treatment of systemic lupus erythematosus (SLE), did not have a significant effect on the primary end point in a previous phase 3 trial. The current phase 3 trial used a secondary end point from that trial as the primary end point.

METHODS

We randomly assigned patients in a 1:1 ratio to receive intravenous anifrolumab (300 mg) or placebo every 4 weeks for 48 weeks. The primary end point of this trial was a response at week 52 defined with the use of the British Isles Lupus Assessment Group (BILAG)-based Composite Lupus Assessment (BICLA). A BICLA response requires reduction in any moderate-to-severe baseline disease activity and no worsening in any of nine organ systems in the BILAG index, no worsening on the Systemic Lupus Erythematosus Disease Activity Index, no increase of 0.3 points or more in the score on the Physician Global Assessment of disease activity (on a scale from 0 [no disease activity] to 3 [severe disease]), no discontinuation of the trial intervention, and no use of medications restricted by the protocol. Secondary end points included a BICLA response in patients with a high interferon gene signature at baseline; reductions in the glucocorticoid dose, in the severity of skin disease, and in counts of swollen and tender joints; and the annualized flare rate.

RESULTS

A total of 362 patients received the randomized intervention: 180 received anifrolumab and 182 received placebo. The percentage of patients who had a BICLA response was 47.8% in the anifrolumab group and 31.5% in the placebo group (difference, 16.3 percentage points; 95% confidence interval, 6.3 to 26.3; P = 0.001). Among patients with a high interferon gene signature, the percentage with a response was 48.0% in the anifrolumab group and 30.7% in the placebo group; among patients with a low interferon gene signature, the percentage was 46.7% and 35.5%, respectively. Secondary end points with respect to the glucocorticoid dose and the severity of skin disease, but not counts of swollen and tender joints and the annualized flare rate, also showed a significant benefit with anifrolumab. Herpes zoster and bronchitis occurred in 7.2% and 12.2% of the patients, respectively, who received anifrolumab. There was one death from pneumonia in the anifrolumab group.

CONCLUSIONS

Monthly administration of anifrolumab resulted in a higher percentage of patients with a response (as defined by a composite end point) at week 52 than did placebo, in contrast to the findings of a similar phase 3 trial involving patients with SLE that had a different primary end point. The frequency of herpes zoster was higher with anifrolumab than with placebo. (Funded by AstraZeneca; ClinicalTrials.gov number, NCT02446899.).

Assays for Inducing and Measuring Cell Death to Detect Macrophage Migration Inhibitory Factor (MIF) Release

Cell death is a vital process for maintaining tissue homeostasis and removing potentially harmful cells. Cell death can be both programmed and non-programmed and is commonly divided into two main forms, termed apoptotic and necrotic death modes. In this chapter cell death is classified into apoptosis, primary necrosis, pyroptosis, and necroptosis. This chapter outlines the measurement of these different types of cell death and the relationship of measuring MIF release in these assays.

Machine learning applied to whole-blood RNA-sequencing data uncovers distinct subsets of patients with systemic lupus erythematosus

Objectives

Systemic lupus erythematosus (SLE) is a heterogeneous autoimmune disease that is difficult to treat. There is currently no optimal stratification of patients with SLE, and thus, responses to available treatments are unpredictable. Here, we developed a new stratification scheme for patients with SLE, based on the computational analysis of patients’ whole‐blood transcriptomes.

Methods

We applied machine learning approaches to RNA‐sequencing (RNA‐seq) data sets to stratify patients with SLE into four distinct clusters based on their gene expression profiles. A meta‐analysis on three recently published whole‐blood RNA‐seq data sets was carried out, and an additional similar data set of 30 patients with SLE and 29 healthy donors was incorporated in this study; a total of 161 patients with SLE and 57 healthy donors were analysed.

Results

Examination of SLE clusters, as opposed to unstratified SLE patients, revealed underappreciated differences in the pattern of expression of disease‐related genes relative to clinical presentation. Moreover, gene signatures correlated with flare activity were successfully identified.

Conclusion

Given that SLE disease heterogeneity is a key challenge hindering the design of optimal clinical trials and the adequate management of patients, our approach opens a new possible avenue addressing this limitation via a greater understanding of SLE heterogeneity in humans. Stratification of patients based on gene expression signatures may be a valuable strategy allowing the identification of separate molecular mechanisms underpinning disease in SLE. Further, this approach may have a use in understanding the variability in responsiveness to therapeutics, thereby improving the design of clinical trials and advancing personalised therapy.

Type I interferon inhibitor anifrolumab in active systemic lupus erythematosus (TULIP-1): a randomised, controlled, phase 3 trial

BACKGROUND

Type I interferons are involved in systemic lupus erythematosus (SLE) pathogenesis. In a phase 2 trial, anifrolumab, a human monoclonal antibody to type I interferon receptor subunit 1, suppressed interferon gene signatures and substantially reduced SLE disease activity. Here, we sought to confirm the efficacy of anifrolumab versus placebo in a phase 3 trial of adult patients with SLE and moderate-to-severe disease activity despite standard-of-care treatment.

METHODS

TULIP-1 was a double-blind, randomised, controlled, phase 3 trial done at 123 sites in 18 countries. Included patients were aged 18-70 years, with moderate-to-severe SLE, and ongoing stable treatment with either prednisone or equivalent, an antimalarial, azathioprine, mizoribine, mycophenolate mofetil or mycophenolic acid, or methotrexate. Patients were randomly assigned (2:1:2) to receive placebo, anifrolumab 150 mg, or anifrolumab 300 mg intravenously every 4 weeks for 48 weeks. Stable standard-of-care treatment continued except for mandatory attempts at oral corticosteroid tapering for patients receiving prednisone or equivalent of 10 mg/day or more at baseline. The primary outcome was the difference between the proportion of patients who achieved an SLE responder index-4 (SRI-4) response at week 52 with anifrolumab 300 mg versus with placebo. Key secondary outcomes were the difference between the anifrolumab 300 mg group and the placebo group in: proportion of patients in the interferon gene signature test-high subgroup who achieved SRI-4 at week 52; proportion of patients on 10 mg/day or more corticosteroids at baseline who achieved a sustained dose reduction to 7·5 mg/day or less from week 40 to 52; proportion of patients with a cutaneous lupus erythematosus disease area and severity index (CLASI) activity score of 10 or higher at baseline who achieved a 50% or more reduction in CLASI score by week 12; proportion of patients who achieved SRI-4 at week 24; and annualised flare rate through week 52. Other measures of disease activity were also assessed at week 52, including the British Isles Lupus Assessment Group-based composite lupus assessment (BICLA). Safety was also assessed. Efficacy and safety analyses were done in the population of patients who received at least one dose of study drug. This trial was registered at ClinicalTrials.gov (NCT02446912).

FINDINGS

Between June 9, 2015, and June 16, 2017, 457 patients were randomly assigned to the anifrolumab 300 mg group (n=180), the anifrolumab 150 mg group (n=93), or the placebo group (n=184). The proportion of patients at week 52 with an SRI-4 response was similar between anifrolumab 300 mg (65 [36%] of 180) and placebo (74 [40%] of 184; difference -4·2 [95% CI -14·2 to 5·8], p=0·41). Similarly, proportions of patients with an SRI-4 response at week 24, and at week 52 in patients in the interferon gene signature test-high subgroup, did not differ between the anifrolumab and placebo groups. In patients with baseline oral corticosteroids of at least 10 mg/day, sustained dose reduction to 7·5 mg/day or less was achieved by 42 (41%) of 103 patients in the anifrolumab 300 mg group and 33 (32%) of 102 patients in the placebo group (difference 8·9 [95% CI -4·1 to 21·9]). In patients with CLASI activity score of at least 10 at baseline, at least 50% reduction by week 12 was achieved by 24 (42%) of 58 patients in the anifrolumab 300 mg group and 14 (25%) of 54 in the placebo group (difference 17·0 [95% CI -0·3 to 34·3]). Annualised flare rates were 0·60 for anifrolumab and 0·72 for placebo (rate ratio 0·83 [95% CI 0·60 to 1·14]). BICLA response was achieved by 67 (37%) of 180 patients receiving anifrolumab 300 mg versus 49 (27%) of 184 receiving placebo (difference 10·1 [95% CI 0·6 to 19·7]). Anifrolumab's safety profile was similar to that observed in phase 2, with similar proportions of patients having a serious adverse event between groups (25 [14%] of 180 for anifrolumab 300 mg, ten [11%] of 93 for anifrolumab 150 mg, and 30 [16%] of 184 for placebo).

INTERPRETATION

The primary endpoint was not reached. However, several secondary endpoints, including reduction in oral corticosteroid dose, CLASI responses, and BICLA responses, suggest clinical benefit of anifrolumab compared with placebo. Conclusive evidence for the efficacy of anifrolumab awaits further phase 3 trial data. Despite the inherent limitations of a 1-year phase 3 study, such as incomplete knowledge of applicability to the general population and scarce detection of rare safety signals, in addition to complications from prespecified restricted medication rules, our results suggest that anifrolumab might have the potential to provide a treatment option for patients who have active SLE while receiving standard therapy.

FUNDING

AstraZeneca.

Lupus low disease activity state as a treatment endpoint for systemic lupus erythematosus: a prospective validation study

BACKGROUND

Treat-to-target strategies have improved outcomes in single-organ diseases with simple clinical or laboratory endpoints. A lack of validated endpoints has prevented adoption of treat to target for complex multiorgan conditions, such as systemic lupus erythematosus (SLE). We report the first prospective study undertaken to specifically validate a treat-to-target endpoint for SLE.

METHODS

In this prospective cohort study, patients aged 18 years or older with SLE were recruited from 13 centres in eight countries and followed prospectively. Patients with at least two visits over the study period no more than 6 months apart were included in the longitudinal analysis. Patients with no visits in the final year of the study were censored from their last visit. Attainment of the lupus low disease activity state (LLDAS) was assessed at each visit. The primary outcome measure was accrual of irreversible end-organ damage, defined as at least a 1-point increase in the Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index. We used time-dependent hazard regression models and generalised linear models to measure the association between LLDAS (attainment at any timepoint, cumulative time in LLDAS, and sustained LLDAS) with accrual of irreversible end-organ damage or flare (key secondary outcome). This study is registered with ClinicalTrials.gov, NCT03138941.

FINDINGS

Between May 1, 2013, and Dec 31, 2016, 1707 patients were recruited and followed for a mean of 2·2 years (SD 0·9), totalling 12 689 visits. Attainment of LLDAS at any timepoint was associated with reduction in damage accrual (hazard ratio 0·59, 0·45-0·76; p<0·0001) and subsequent flare (0·65, 95% CI 0·56-0·75; p<0·0001). Cumulative time in LLDAS was associated with improved outcomes: compared with patients with less than 50% of observed time in LLDAS, those with at least 50% of observed time in LLDAS had reduced risk of damage accrual (0·54, 0·42-0·70; p<0·0001) and flare (0·41, 0·35-0·48; p<0·0001). Similarly, increased durations of sustained LLDAS were associated with incremental reductions in the risk of damage accrual. The association of LLDAS with reduced damage accrual was observed regardless of pre-existing damage or disease activity at study entry.

INTERPRETATION

LLDAS attainment is associated with significant protection against flare and damage accrual in SLE. These findings validate LLDAS as an endpoint for clinical studies in SLE.

FUNDING

The Asia Pacific Lupus Collaboration received project support grants from UCB Pharma, GlaxoSmithKline, Janssen, Bristol-Myers Squibb, and AstraZeneca.

Evaluation of remission definitions for systemic lupus erythematosus: a prospective cohort study

BACKGROUND

Validated outcome measures are needed from which to derive treatment strategies for systemic lupus erythematosus (SLE). However, no definition of remission for SLE has been widely adopted. The Definitions of Remission in Systemic Lupus Erythematosus (DORIS) group has proposed a framework with multiple potential definitions of remission. In this study, we aimed to assess the attainability and effect on disease outcomes of the DORIS definitions of remission, compared with the lupus low disease activity state (LLDAS), in patients with SLE.

METHODS

In this prospective cohort study, we enrolled patients with SLE from 13 international centres that are part of the Asia Pacific Lupus Collaboration. Eligible patients were older than 18 years and fulfilled one of two classification criteria for SLE (1997 American College of Rheumatology criteria or the 2012 Systemic Lupus International Collaborating Clinics criteria). Visits were according to clinical need, with a minimum frequency of one visit per 6 months. We assessed attainment of remission on the basis of the eight DORIS definitions of remission, which varied in terms of serological activity, glucocorticoid use, and use of immunosuppresive agents; attainment of LLDAS; and disease flares at each visit. Irreversible organ damage accrual was recorded annually. Our primary aim was to assess exposure of patients to each of the remission definitions or LLDAS, and the respective association of these states with accrual of irreversible organ damage as the primary outcome measure. Occurrence of disease flares was the key secondary outcome. We used time-dependent Cox proportional hazards models and generalised linear models to assess DORIS definitions of remission and LLDAS in terms of their association with damage accrual and disease flares.

FINDINGS

Between May 1, 2013, and Dec 31, 2016, 1707 patients with SLE were recruited and followed for a mean of 2·2 years (SD 0·9), totalling 12 689 visits. Remission, depending on DORIS definition, was achieved in 581 (4·6%) to 4546 (35·8%) of 12 689 visits. Spending 50% or more of observed time in any remission state was associated with a significant reduction in damage accrual, except for the two most stringent remission definitions, for which the frequency of attainment was lowest. Remission definitions disallowing serological activity were associated with the greatest reductions in disease flares. LLDAS was more attainable than any remission definition and was associated with a similar magnitude of protection from damage accrual and disease flares. Sustained remission and LLDAS were associated with a wider spread of effect sizes for reduction in risk of damage. By analysing patients who met the definition for LLDAS but not remission, we found that LLDAS was significantly associated with reduction in damage accrual, independent of all definitions of remission, except the least stringent.

INTERPRETATION

Attainment of remission was associated with significant reductions in damage accrual and disease flares. LLDAS was more achievable than remission based on the DORIS criteria, but was similarly protective. Remission definitions with less stringency might be insufficiently distinct from LLDAS to substantially affect outcome measures, and further studies are needed to distinguish the protective effects of the various remission definitions.

FUNDING

UCB, GlaxoSmithKline, Janssen, Bristol-Myers Squibb, and AstraZeneca.

Novel Methods of Incorporating Time in Longitudinal Multivariate Analysis Reveals Hidden Associations With Disease Activity in Systemic Lupus Erythematosus

Objective: Systemic lupus erythematosus (SLE) is a multisystem autoimmune disease. SLE is characterized by high inter-patient variability, including fluctuations over time, a factor which most biomarker studies omit from consideration. We investigated relationships between disease activity and biomarker expression in SLE, using novel methods to control for time-dependent variability, in a proof-of-concept study to evaluate whether doing so revealed additional information.

Methods: We measured 4 serum biomarkers (MIF, CCL2, CCL19, and CXCL10) and 13 routine clinical laboratory parameters, alongside disease activity measured by the SLE disease activity index-2k (SLEDAI-2k), collected longitudinally. We analyzed these data with unsupervised learning methods via ensemble clustering, incorporating temporal relationships using dynamic time warping for distance metric calculation.

Results: Data from 843 visits in 110 patients (median age 47, 83% female) demonstrated highly heterogeneous time-dependent relationships between disease activity and biomarkers. Unbiased magnitude-based hierarchical clustering of biomarker expression levels isolated a patient subset (n = 9) with distinctively heterogeneous expression of the 17 biological parameters, and who had MIF, CCL2, CCL19, and CXCL10 levels that were higher and more strongly associated with disease activity, based on leave-one-out cross-validated regression analysis. In the remaining subgroup, a time-dependent regression model revealed significantly stronger predictive power of biomarkers for disease activity, compared to a time-agnostic regression model. Despite no significant difference in simple magnitude, using dynamic time warping analysis to align longitudinal profiles revealed a large subset (n = 69) with significantly stronger associations between biological parameters and disease activity. This subgroup had significantly lower flare rates, disease activity and damage scores, suggesting this clustering is clinically meaningful.

Conclusions: These results suggest associations between biological parameters and disease activity in SLE exist in a multi-dimensional time-dependent pattern, with implications for the analysis of biomarkers in SLE often used to identify therapeutic targets. Novel methods to analyse high-dimensional data and control for time-dependent variability may have broad utility in the study complex relationships between clinical and biological parameters.

Could GILZ Be the Answer to Glucocorticoid Toxicity in Lupus?

Glucocorticoids (GC) are used globally to treat autoimmune and inflammatory disorders. Their anti-inflammatory actions are mainly mediated via binding to the glucocorticoid receptor (GR), creating a GC/GR complex, which acts in both the cytoplasm and nucleus to regulate the transcription of a host of target genes. As a result, signaling pathways such as NF-κB and AP-1 are inhibited, and cell activation, differentiation and survival and cytokine and chemokine production are suppressed. However, the gene regulation by GC can also cause severe side effects in patients. Systemic lupus erythematosus (SLE or lupus) is a multisystem autoimmune disease, characterized by a poorly regulated immune response leading to chronic inflammation and dysfunction of multiple organs, for which GC is the major current therapy. Long-term GC use, however, can cause debilitating adverse consequences for patients including diabetes, cardiovascular disease and osteoporosis and contributes to irreversible organ damage. To date, there is no alternative treatment which can replicate the rapid effects of GC across multiple immune cell functions, effecting disease control during disease flares. Research efforts have focused on finding alternatives to GC, which display similar immunoregulatory actions, without the devastating adverse metabolic effects. One potential candidate is the glucocorticoid-induced leucine zipper (GILZ). GILZ is induced by low concentrations of GC and is shown to mimic the action of GC in several inflammatory processes, reducing immunity and inflammation in in vitro and in vivo studies. Additionally, GILZ has, similar to the GC-GR complex, the ability to bind to both NF-κB and AP-1 as well as DNA directly, to regulate immune cell function, while potentially lacking the GC-related side effects. Importantly, in SLE patients GILZ is under-expressed and correlates negatively with disease activity, suggesting an important regulatory role of GILZ in SLE. Here we provide an overview of the actions and use of GC in lupus, and discuss whether the regulatory mechanisms of GILZ could lead to the development of a novel therapeutic for lupus. Increased understanding of the mechanisms of action of GILZ, and its ability to regulate immune events leading to lupus disease activity has important clinical implications for the development of safer anti-inflammatory therapies.

Analysis of serum B cell-activating factor from the tumor necrosis factor family (BAFF) and its soluble receptors in systemic lupus erythematosus

Objectives

To determine the presence and clinical associations of the soluble receptors of B cell-activating factor from the tumor necrosis factor family (BAFF) in serum of patients with systemic lupus erythematosus (SLE).

Methods

Serum BAFF and soluble BAFF receptor (sBAFF-R) were quantified using ELISA, and soluble B cell maturation antigen (sBCMA) and transmembrane activator and cyclophilin ligand interactor (sTACI) by Luminex, in 87 SLE patients and 17 healthy controls (HC). Disease activity and organ damage were assessed using SLE Disease Activity Index 2000 (SLEDAI-2K) and Systemic Lupus International Collaborating Clinics (SLICC) SLE Damage Index (SDI), respectively.

Results

BAFF and all receptors were detectable in all serum samples. Serum sBCMA and sTACI, but not sBAFF-R, were significantly higher in SLE than in HC. Serum BAFF was also increased in SLE, but this association was attenuated after adjusting for age and ethnicity. Increased serum BAFF was associated with flare and organ damage. Increased serum sBCMA was associated with the presence of anti-dsDNA, but not with overall or organ-specific disease activity, flare or organ damage. Neither sTACI nor sBAFF-R was associated with any SLE clinical parameters in multivariable analysis. While serum BAFF correlated negatively with sBAFF-R in HC, no statistically significant correlations were observed between BAFF and its receptors in SLE patients.

Conclusion

Serum BAFF was associated with flare and organ damage independent of the presence of its soluble receptors. While sBCMA was associated with anti-dsDNA positivity, other soluble BAFF receptors were not associated with SLE clinical indicators.

Analysis of serum interleukin(IL)-1α, IL-1β and IL-18 in patients with systemic sclerosis

Objectives

Systemic sclerosis (SSc) is an autoimmune disease characterised by fibrosis, vascular dysfunction and immune dysregulation. The pathogenesis of SSc remains poorly understood, although studies have indicated a role for the innate immune response.

Methods

Here, we measured serum interleukin (IL)‐1α, IL‐1β and IL‐18 levels in 105 SSc patients and 47 healthy controls (HC) and analysed them with respect to multiple clinical parameters.

Results

Serum IL‐18 concentrations were significantly higher in SSc patients than in HC, while no significant differences in concentrations of IL‐1α and IL‐1β were observed between SSc and HC. In both SSc and HC serum, IL‐1α and IL‐1β were positively correlated, while in SSc, both cytokines negatively correlated with IL‐18. Serum IL‐18 was significantly negatively correlated with both carbon monoxide transfer coefficient (KCO) and diffusing capacity of the lungs for carbon monoxide (DLCO). Serum IL‐1β was positively correlated with the modified Rodnan skin score (mRSS), particularly in patients with limited subtype. DLCO, KCO and tricuspid regurgitation (TR) velocity were significantly higher in patients with high serum IL‐1β. Serum IL‐1α was significantly lower in SSc patients with low KCO and positively correlated with KCO. SSc patients with high serum IL‐1α concentrations were more likely to have digital ulcers.

Conclusions

Our data suggest that these IL‐1 family cytokines may have different roles in the pathogenesis of SSc fibrotic complications.

Lupus Low Disease Activity State (LLDAS) discriminates responders in the BLISS-52 and BLISS-76 phase III trials of belimumab in systemic lupus erythematosus

OBJECTIVE

We evaluated the discriminant capacity of the Lupus Low Disease Activity State (LLDAS) in post-hoc analysis of data from the BLISS-52 and BLISS-76 trials of belimumab in systemic lupus erythematosus (SLE).

METHODS

LLDAS attainment, discrimination between belimumab and placebo arms, and the effects in subgroups with high disease activity at recruitment were evaluated at week 52 using appropriate descriptive statistics, χ² test and logistic regression.

RESULTS

At week 52, for belimumab 10 mg/kg, 17.0% and 19.3% of patients who achieved a Systemic Lupus Erythematosus Responder Index-4 also attained LLDAS in BLISS-52 and BLISS-76, respectively. Significantly more patients attained LLDAS on belimumab 10 mg/kg compared with placebo (12.5% vs 5.8%, OR 2.32, p=0.02 for BLISS-52; 14.4% vs 7.8%, OR 1.98, p=0.04 for BLISS-76). In a subgroup analysis, the difference in week 52 LLDAS attainment between belimumab 10 mg/kg and placebo was greater in patients who had higher disease activity at baseline, compared with the overall group.

CONCLUSIONS

LLDAS was able to discriminate belimumab 10 mg/kg from placebo in the BLISS-52 and BLISS-76 trials. Our findings support the validity of LLDAS as an outcome measure in SLE clinical trials.

Analysis of serum macrophage migration inhibitory factor and D-dopachrome tautomerase in systemic sclerosis

Objectives

Macrophage migration inhibitory factor (MIF) and D‐dopachrome tautomerase (DDT), members of the same cytokine superfamily, are linked to the pathogenesis of a number of inflammatory diseases. The aim of this study was to investigate their clinical relevance in systemic sclerosis (SSc).

Methods

Serum MIF and DDT were quantified in 105 SSc patients by ELISA and levels compared to healthy controls (HC) (47) and patients with systemic lupus erythematosus (SLE) (184). Clinical parameters included organ involvement, serum laboratory markers and results of pulmonary function tests, and overall disease activity assessed using the European Scleroderma Trials and Research group (EUSTAR) activity index.

Results

There was no significant difference in serum DDT concentrations between patients with SSc and HC. However, serum MIF was significantly increased in SSc compared to both HC and SLE cohorts. Serum MIF was increased in SSc patients with low forced vital capacity (FVC) and was also associated with the use of angiotensin II receptor blockers and beta blockers in SSc, confirmed after adjusting for the presence of systemic hypertension and low FVC. Serum DDT was significantly higher in SSc patients with low FEV1 and negatively correlated with EUSTAR score, particularly in patients with limited disease.

Conclusion

Although not significantly linked to specific clinical parameters, serum MIF was significantly higher in SSc patients than in HC and SLE patients, suggesting a fundamental role for MIF in SSc. DDT, while closely related to MIF, did not show a similar expression profile, suggesting functional differences between these molecules.