Association of autoantibody concentrations and trajectories with lupus nephritis histological features and treatment response.

OBJECTIVE: Autoantibodies are a hallmark of lupus nephritis (LN), but their association with LN classes and treatment response are not adequately known. In this study, we quantified circulating autoantibodies in the Accelerating Medicines Partnership (AMP) LN longitudinal cohort to identify serological biomarkers of LN histological classification and treatment response, and how these biomarkers change over time based on treatment response. METHODS: Peripheral blood samples were collected from 279 SLE patients undergoing diagnostic kidney biopsy based on proteinuria. Of these, 268 were diagnosed with LN. Thirteen autoantibody specificities were measured by bead-based assays (Bio-Rad Bioplex 2200) and anti-C1q by ELISA at the time of biopsy (baseline) and at 3-, 6-, and 12-months post-biopsy. Clinical response was determined at 12 months. RESULTS: Proliferative LN (ISN/RPS class III/IV+V, n=160) was associated with higher concentrations of anti-C1q, -chromatin, -dsDNA, and -ribosomal P autoantibodies compared to non-proliferative LN (classes I/II/V/VI, n=108). Anti-C1q and-dsDNA were independently associated with proliferative LN. In proliferative LN, higher baseline anti-C1q levels predicted complete response (AUC, 0.72; p, 0.002) better than baseline proteinuria (0.59; 0.21). Furthermore, all autoantibody levels, except for anti-La/SSB, decreased over 12 months in proliferative, but not membranous, LN patients with a complete response. CONCLUSIONS: Baseline levels of anti-C1q and -dsDNA may serve as noninvasive biomarkers of proliferative LN, and anti-C1q may predict complete response at the time of kidney biopsy. In addition, tracking autoantibodies over time may provide further insights into treatment response and pathogenic mechanisms in proliferative LN patients.

Extrarenal symptoms associate with worse quality of life in patients enrolled in the AMP RA/SLE Lupus Nephritis Network.

OBJECTIVE: Lupus nephritis (LN) can occur as an isolated component of disease activity or be accompanied by diverse extrarenal manifestations. Whether isolated renal disease is sufficient to decrease health related quality of life (HRQOL) remains unknown. This study compared Patient-Reported Outcomes Measurement Information System 29-Item (PROMIS-29) scores in LN patients with isolated renal disease to those with extrarenal symptoms to evaluate the burden of LN on HRQOL and inform future LN clinical trials incorporating HRQOL outcomes. METHODS: A total of 181 LN patients consecutively enrolled in the multicentre multi-ethnic/racial Accelerating Medicines Partnership completed PROMIS-29 questionnaires at the time of a clinically indicated renal biopsy. Raw PROMIS-29 scores were converted to standardized T scores. RESULTS: Seventy-five (41%) patients had extrarenal disease (mean age 34, 85% female) and 106 (59%) had isolated renal (mean age 36, 82% female). Rash (45%), arthritis (40%) and alopecia (40%) were the most common extrarenal manifestations. Compared with isolated renal, patients with extrarenal disease reported significantly worse pain interference, ability to participate in social roles, physical function, and fatigue. Patients with extrarenal disease had PROMIS-29 scores that significantly differed from the general population by > 0.5 SD of the reference mean in pain interference, physical function, and fatigue. Arthritis was most strongly associated with worse scores in these three domains. CONCLUSION: Most patients had isolated renal disease and extrarenal manifestations associated with worse HRQOL. These data highlight the importance of comprehensive disease management strategies that address both renal and extrarenal manifestations to improve overall patient outcomes.

Mycophenolate mofetil withdrawal in patients with systemic lupus erythematosus: a multicentre, open-label, randomised controlled trial.

BACKGROUND: Mycophenolate mofetil is an immunosuppressant commonly used to treat systemic lupus erythematosus (SLE) and lupus nephritis. It is a known teratogen associated with significant toxicities, including an increased risk of infections and malignancies. Mycophenolate mofetil withdrawal is desirable once disease quiescence is reached, but the timing of when to do so and whether it provides a benefit has not been well-studied. We aimed to determine the effects of mycophenolate mofetil withdrawal on the risk of clinically significant disease reactivation in patients with quiescent SLE on long-term mycophenolate mofetil therapy. METHODS: This multicenter, open-label, randomised trial was conducted in 19 centres in the USA. Eligible patients were aged between 18 and 70 years old, met the American College of Rheumatology (ACR) 1997 SLE criteria, and had a clinical SLEDAI score of less than 4 at screening. Mycophenolate mofetil therapy was required to be stable or decreasing for 2 years or more if initiated for renal indications, or for 1 year or more for non-renal indications. Participants were randomly allocated in a 1:1 ratio to a withdrawal group, who tapered off mycophenolate mofetil over 12 weeks, or a maintenance group who maintained their baseline dose (1-3g per day) for 60 weeks. Adaptive random allocation ensured groups were balanced for study site, renal versus non-renal disease, and baseline mycophenolate mofetil dose (≥2 g per day vs <2 g per day). Clinically significant disease reactivation by week 60 following random allocation, requiring increased doses or new immunosuppressive therapy was the primary endpoint, in the modified intention-to-treat population (all randomly allocated participants who began study-provided mycophenolate mofetil). Non-inferiority was evaluated using an estimation-based approach. The trial was registered at ClinicalTrials.gov (NCT01946880) and is completed. FINDINGS: Between Nov 6, 2013, and April 27, 2018, 123 participants were screened, of whom 102 were randomly allocated to the maintenance group (n=50) or the withdrawal group (n=52). Of the 100 participants included in the modified intention-to-treat analysis (49 maintenance, 51 withdrawal), 84 (84%) were women, 16 (16%) were men, 40 (40%) were White, 41 (41%) were Black, and 76 (76%) had a history of lupus nephritis. The average age was 42 (SD 12·7). By week 60, nine (18%) of 51 participants in the withdrawal group had clinically significant disease reactivation, compared to five (10%) of 49 participants in the maintenance group. The risk of clinically significant disease reactivation was 11% (95% CI 5-24) in the maintenance group and 18% (10-32) in the withdrawal group. The estimated increase in the risk of clinically significant disease reactivation with mycophenolate mofetil withdrawal was 7% (one-sided upper 85% confidence limit 15%). Similar rates of adverse events were observed in the maintenance group (45 [90%] of 50 participants) and the withdrawal group (46 [88%] of 52 participants). Infections were more frequent in the mycophenolate mofetil maintenance group (32 [64%]) compared with the withdrawal group (24 [46%]). INTERPRETATIONS: Mycophenolate mofetil withdrawal is not significantly inferior to mycophenolate mofetil maintenance. Estimates for the rates of disease reactivation and increases in risk with withdrawal can assist clinicians in making informed decisions on withdrawing mycophenolate mofetil in patients with stable SLE. FUNDING: The National Institute of Allergy and Infectious Diseases and the National Institute of Arthritis and Musculoskeletal and Skin Diseases.

Longitudinal patterns and predictors of response to standard-of-care therapy in lupus nephritis: data from the Accelerating Medicines Partnership Lupus Network.

BACKGROUND: Leveraging the Accelerating Medicines Partnership (AMP) Lupus Nephritis (LN) dataset, we evaluated longitudinal patterns, rates, and predictors of response to standard-of-care therapy in patients with lupus nephritis. METHODS: Patients from US academic medical centers with class III, IV, and/or V LN and a baseline urine protein/creatinine (UPCR) ratio ≥ 1.0 (n = 180) were eligible for this analysis. Complete response (CR) required the following: (1) UPCR < 0.5; (2) normal serum creatinine (≤ 1.3 mg/dL) or, if abnormal, ≤ 125% of baseline; and (3) prednisone ≤ 10 mg/day. Partial response (PR) required the following: (1) > 50% reduction in UPCR; (2) normal serum creatinine or, if abnormal, ≤ 125% of baseline; and (3) prednisone dose ≤ 15 mg/day. RESULTS: Response rates to the standard of care at week 52 were CR = 22.2%; PR = 21.7%; non-responder (NR) = 41.7%, and not determined (ND) = 14.4%. Only 8/180 (4.4%) patients had a week 12 CR sustained through week 52. Eighteen (10%) patients attained a week 12 PR or CR and sustained their responses through week 52 and 47 (26.1%) patients achieved sustained PR or CR at weeks 26 and 52. Week 52 CR or PR attainment was associated with baseline UPCR > 3 (ORadj = 3.71 [95%CI = 1.34-10.24]; p = 0.012), > 25% decrease in UPCR from baseline to week 12 (ORadj = 2.61 [95%CI = 1.07-6.41]; p = 0.036), lower chronicity index (ORadj = 1.33 per unit decrease [95%CI = 1.10-1.62]; p = 0.003), and positive anti-dsDNA antibody (ORadj = 2.61 [95%CI = 0.93-7.33]; p = 0.069). CONCLUSIONS: CR and PR rates at week 52 were consistent with the standard-of-care response rates observed in prospective registrational LN trials. Low sustained response rates underscore the need for more efficacious therapies and highlight how critically important it is to understand the molecular pathways associated with response and non-response.

Autoantibodies identify primary Sjögren's syndrome in patients lacking serum IgG specific for Ro/SS-A and La/SS-B.

OBJECTIVE: Identify autoantibodies in anti-Ro/SS-A negative primary Sjögren's syndrome (SS). METHODS: This is a proof-of-concept, case-control study of SS, healthy (HC) and other disease (OD) controls. A discovery dataset of plasma samples (n=30 SS, n=15 HC) was tested on human proteome arrays containing 19 500 proteins. A validation dataset of plasma and stimulated parotid saliva from additional SS cases (n=46 anti-Ro+, n=50 anti-Ro-), HC (n=42) and OD (n=54) was tested on custom arrays containing 74 proteins. For each protein, the mean+3 SD of the HC value defined the positivity threshold. Differences from HC were determined by Fisher's exact test and random forest machine learning using 2/3 of the validation dataset for training and 1/3 for testing. Applicability of the results was explored in an independent rheumatology practice cohort (n=38 Ro+, n=36 Ro-, n=10 HC). Relationships among antigens were explored using Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) interactome analysis. RESULTS: Ro+ SS parotid saliva contained autoantibodies binding to Ro60, Ro52, La/SS-B and muscarinic receptor 5. SS plasma contained 12 novel autoantibody specificities, 11 of which were detected in both the discovery and validation datasets. Binding to ≥1 of the novel antigens identified 54% of Ro- SS and 37% of Ro+ SS cases, with 100% specificity in both groups. Machine learning identified 30 novel specificities showing receiver operating characteristic area under the curve of 0.79 (95% CI 0.64 to 0.93) for identifying Ro- SS. Sera from Ro- cases of an independent cohort bound 17 of the non-canonical antigens. Antigenic targets in both Ro+ and Ro- SS were part of leukaemia cell, ubiquitin conjugation and antiviral defence pathways. CONCLUSION: We identified antigenic targets of the autoantibody response in SS that may be useful for identifying up to half of Ro seronegative SS cases.

High incidence of proliferative and membranous nephritis in SLE patients with low proteinuria in the Accelerating Medicines Partnership.

OBJECTIVE: Delayed detection of LN associates with worse outcomes. There are conflicting recommendations regarding a threshold level of proteinuria at which biopsy will likely yield actionable management. This study addressed the association of urine protein:creatinine ratios (UPCR) with clinical characteristics and investigated the incidence of proliferative and membranous histology in patients with a UPCR between 0.5 and 1. METHODS: A total of 275 SLE patients (113 first biopsy, 162 repeat) were enrolled in the multicentre multi-ethnic/racial Accelerating Medicines Partnership across 15 US sites at the time of a clinically indicated renal biopsy. Patients were followed for 1 year. RESULTS: At biopsy, 54 patients had UPCR <1 and 221 had UPCR ≥1. Independent of UPCR or biopsy number, a majority (92%) of patients had class III, IV, V or mixed histology. Moreover, patients with UPCR <1 and class III, IV, V, or mixed had a median activity index of 4.5 and chronicity index of 3, yet 39% of these patients had an inactive sediment. Neither anti-dsDNA nor low complement distinguished class I or II from III, IV, V or mixed in patients with UPCR <1. Of 29 patients with baseline UPCR <1 and class III, IV, V or mixed, 23 (79%) had a UPCR <0.5 at 1 year. CONCLUSION: In this prospective study, three-quarters of patients with UPCR <1 had histology showing class III, IV, V or mixed with accompanying activity and chronicity despite an inactive sediment or normal serologies. These data support renal biopsy at thresholds lower than a UPCR of 1.

TLR engagement induces ARID3a in human blood hematopoietic progenitors and modulates IFNα production.

The DNA binding protein AT-rich interacting domain 3a (ARID3a)2 is expressed in healthy human hematopoietic cord blood progenitors where its modulation influences myeloid versus B lineage development. ARID3a is also variably expressed in subsets of adult peripheral blood hematopoietic progenitors where the consequences of ARID3a expression are unknown. In B lymphocytes, Toll-like receptor (TLR)3 signaling induces ARID3a expression in association with Type I interferon inflammatory cytokines. We hypothesized that TLR ligand stimulation of peripheral blood hematopoietic progenitors would induce ARID3a expression resulting in interferon production, and potentially influencing lineage decisions. Our data revealed that the TLR9 agonist CpG induces ARID3a expression with interferon alpha synthesis in human hematopoietic progenitors. However, ARID3a expression was not associated with increased B lineage development. These results demonstrate the need for further experiments to better define how pathogen-associated responses influence hematopoiesis.

Unique Sjögren's syndrome patient subsets defined by molecular features.

OBJECTIVE: To address heterogeneity complicating primary SS (pSS) clinical trials, research and care by characterizing and clustering patients by their molecular phenotypes. METHODS: pSS patients met American-European Consensus Group classification criteria and had at least one systemic manifestation and stimulated salivary flow of ⩾0.1 ml/min. Correlated transcriptional modules were derived from gene expression microarray data from blood (n = 47 with appropriate samples). Patients were clustered based on this molecular information using an unbiased random forest modelling approach. In addition, multiplex, bead-based assays and ELISAs were used to assess 30 serum cytokines, chemokines and soluble receptors. Eleven autoantibodies, including anti-Ro/SSA and anti-La/SSB, were measured by Bio-Rad Bioplex 2200. RESULTS: Transcriptional modules distinguished three clusters of pSS patients. Cluster 1 showed no significant elevation of IFN or inflammation modules. Cluster 2 showed strong IFN and inflammation modular network signatures, as well as high plasma protein levels of IP-10/CXCL10, MIG/CXCL9, BLyS (BAFF) and LIGHT. Cluster 3 samples exhibited moderately elevated IFN modules, but with suppressed inflammatory modules, increased IP-10/CXCL10 and B cell-attracting chemokine 1/CXCL13 and trends toward increased MIG/CXCL9, IL-1α, and IL-21. Anti-Ro/SSA and anti-La/SSB were present in all three clusters. CONCLUSION: Molecular profiles encompassing IFN, inflammation and other signatures can be used to separate patients with pSS into distinct clusters. In the future, such profiles may inform patient selection for clinical trials and guide treatment decisions.

Epstein Barr virus nuclear antigen 1 (EBNA-1) peptides recognized by adult multiple sclerosis patient sera induce neurologic symptoms in a murine model.

Multiple sclerosis (MS) is an autoimmune demyelinating disease with progressive neurodegeneration and complex etiology likely involving genetic and environmental factors. MS has been associated with Epstein Barr virus (EBV) infection, with patients often showing enhanced responses to EBV antigens. To determine whether abnormal EBV nuclear antigen-1 (EBNA-1) humoral immunity can serve as an initiator of autoimmune responses in MS, we investigated the fine specificities of the humoral immune response against EBNA-1 in MS patients using solid phase epitope mapping. Antibodies from MS patients recognized an EBNA-1 epitope spanning amino acids 411-426, previously unknown to be recognized specifically by untreated MS patients. Antibodies against this epitope cross-reacted to myelin basic protein (MBP). Furthermore, animals immunized with this EBNA-1 polypeptide mounted a response against MBP and developed signs of experimental autoimmune encephalitis (EAE). These data support a link between MS and EBV through antibodies that cross-react between EBV proteins and the MBP autoantigen.

PD-1hiCXCR5- T peripheral helper cells promote B cell responses in lupus via MAF and IL-21.

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by pathologic T cell-B cell interactions and autoantibody production. Defining the T cell populations that drive B cell responses in SLE may enable design of therapies that specifically target pathologic cell subsets. Here, we evaluated the phenotypes of CD4+ T cells in the circulation of 52 SLE patients drawn from multiple cohorts and identified a highly expanded PD-1hiCXCR5-CD4+ T cell population. Cytometric, transcriptomic, and functional assays demonstrated that PD-1hiCXCR5-CD4+ T cells from SLE patients are T peripheral helper (Tph) cells, a CXCR5- T cell population that stimulates B cell responses via IL-21. The frequency of Tph cells, but not T follicular helper (Tfh) cells, correlated with both clinical disease activity and the frequency of CD11c+ B cells in SLE patients. PD-1hiCD4+ T cells were found within lupus nephritis kidneys and correlated with B cell numbers in the kidney. Both IL-21 neutralization and CRISPR-mediated deletion of MAF abrogated the ability of Tph cells to induce memory B cell differentiation into plasmablasts in vitro. These findings identify Tph cells as a highly expanded T cell population in SLE and suggest a key role for Tph cells in stimulating pathologic B cell responses.

Association of Epstein-Barr virus serological reactivation with transitioning to systemic lupus erythematosus in at-risk individuals.

OBJECTIVE: Systemic lupus erythematosus (SLE) is a systemic autoimmune disease with unknown aetiology. Epstein-Barr virus (EBV) is an environmental factor associated with SLE. EBV maintains latency in B cells with frequent reactivation measured by antibodies against viral capsid antigen (VCA) and early antigen (EA). In this study, we determined whether EBV reactivation and single nucleotide polymorphisms (SNPs) in EBV-associated host genes are associated with SLE transition. METHODS: SLE patient relatives (n=436) who did not have SLE at baseline were recontacted after 6.3 (±3.9) years and evaluated for interim transitioning to SLE (≥4 cumulative American College of Rheumatology criteria); 56 (13%) transitioned to SLE prior to the follow-up visit. At both visits, detailed demographic, environmental, clinical information and blood samples were obtained. Antibodies against viral antigens were measured by ELISA. SNPs in IL10, CR2, TNFAIP3 and CD40 genes were typed by ImmunoChip. Generalised estimating equations were used to test associations between viral antibody levels and transitioning to SLE. RESULTS: Mean baseline VCA IgG (4.879±1.797 vs 3.866±1.795, p=0.0003) and EA IgG (1.192±1.113 vs 0.7774±0.8484, p=0.0236) levels were higher in transitioned compared with autoantibody negative non-transitioned relatives. Increased VCA IgG and EA IgG were associated with transitioning to SLE (OR 1.28 95% CI 1.07 to 1.53, p=0.007, OR 1.43 95% CI 1.06 to 1.93, p=0.02, respectively). Significant interactions were observed between CD40 variant rs48100485 and VCA IgG levels and IL10 variant rs3024493 and VCA IgA levels in transitioning to SLE. CONCLUSION: Heightened serologic reactivation of EBV increases the probability of transitioning to SLE in unaffected SLE relatives.

Immunologic findings precede rapid lupus flare after transient steroid therapy.

Systemic lupus erythematosus (SLE) flares elicit progressive organ damage, leading to disability and early mortality. This study evaluated clinical and immunologic factors associated with impending flare in the Biomarkers of Lupus Disease study. Autoantibodies and 32 soluble mediators were measured by multiplex assays, immune pathway activation by gene expression module scores, and immune cell subset frequencies and activation states by flow cytometry. After providing baseline samples, participants received transient steroids to suppress disease and were followed until flare. Flare occurred early (within 60 days of baseline) in 21 participants and late (90-165 days) in 13. At baseline, compared to the late flare group, the early flare group had differential gene expression in monocyte, T cell, interferon, and inflammation modules, as well as significantly higher frequencies of activated (aCD11b+) neutrophils and monocytes, and activated (CD86hi) naïve B cells. Random forest models showed three subgroups of early flare patients, distinguished by greater baseline frequencies of aCD11b+ monocytes, or CD86hi naïve B cells, or both. Increases in these cell populations were the most accurate biomarkers for early flare in this study. These results suggest that SLE flares may arise from an overlapping spectrum of lymphoid and myeloid mechanisms in different patients.

Resequencing Study Confirms That Host Defense and Cell Senescence Gene Variants Contribute to the Risk of Idiopathic Pulmonary Fibrosis.

Rationale: Several common and rare genetic variants have been associated with idiopathic pulmonary fibrosis, a progressive fibrotic condition that is localized to the lung. Objectives: To develop an integrated understanding of the rare and common variants located in multiple loci that have been reported to contribute to the risk of disease. Methods: We performed deep targeted resequencing (3.69 Mb of DNA) in cases (n = 3,624) and control subjects (n = 4,442) across genes and regions previously associated with disease. We tested for associations between disease and 1) individual common variants via logistic regression and 2) groups of rare variants via sequence kernel association tests. Measurements and Main Results: Statistically significant common variant association signals occurred in all 10 of the regions chosen based on genome-wide association studies. The strongest risk variant is the MUC5B promoter variant rs35705950, with an odds ratio of 5.45 (95% confidence interval, 4.91-6.06) for one copy of the risk allele and 18.68 (95% confidence interval, 13.34-26.17) for two copies of the risk allele (P = 9.60 × 10-295). In addition to identifying for the first time that rare variation in FAM13A is associated with disease, we confirmed the role of rare variation in the TERT and RTEL1 gene regions in the risk of IPF, and found that the FAM13A and TERT regions have independent common and rare variant signals. Conclusions: A limited number of common and rare variants contribute to the risk of idiopathic pulmonary fibrosis in each of the resequencing regions, and these genetic variants focus on biological mechanisms of host defense and cell senescence.

Epstein Barr Virus Interleukin 10 Suppresses Anti-inflammatory Phenotype in Human Monocytes.

Epstein Barr virus (EBV) is a gamma herpes virus associated with certain malignancies and autoimmune diseases. EBV maintains latency in B cells with occasional reactivation, in part by overcoming the host immune response with viral homologs of several human proteins. EBV interleukin 10 (vIL-10), a lytic phase protein, is a homolog of human IL-10 (hIL-10). The effect of vIL-10 on human monocytes, which are one of the first immune cells to respond to infection, is not known. To understand the role of vIL-10, monocytes from peripheral blood mononuclear cells were stimulated with hIL-10 or vIL-10. Human IL-10 stimulated STAT3 phosphorylation, which is required for suppression of inflammatory responses. However, vIL-10 induced significantly lower phosphorylation of STAT3 compared to hIL-10, and was less efficient in downregulating inflammatory genes. vIL-10 significantly reduced the expression of scavenger receptor CD163 on monocytes, suggesting inhibition of M2 polarization. Furthermore, uptake of apoptotic cells was reduced in vIL-10-stimulated monocytes compared to hIL-10-stimulated monocytes. A neutralizing antibody to IL-10R1 inhibited STAT3 phosphorylation induced by either hIL-10 or vIL-10, suggesting that vIL-10 signals through IL-10R1. Interestingly, vIL-10 suppressed hIL-10-induced STAT3 phosphorylation and inhibited upregulation of suppressors of inflammatory response by hIL-10. We further show that vIL-10 levels were significantly higher in plasma samples from systemic lupus erythematosus (SLE) patients compared to matched unaffected controls. vIL-10 levels did not correlate with hIL-10 levels, but were associated with levels of IgA antibodies to EBV viral capsid antigen, which is an indirect measure of viral reactivation. We propose that the suppression of hIL-10- induced anti-inflammatory genes by vIL-10, together with an increase in inflammatory gene expression, may overcome the anti-inflammatory effects of hIL-10 and exacerbate autoimmune responses in systemic autoimmune diseases.

Clinical Efficacy and Safety of Baminercept, a Lymphotoxin ß Receptor Fusion Protein, in Primary Sjögren's Syndrome: Results From a Phase II Randomized, Double-Blind, Placebo-Controlled Trial.

OBJECTIVE: To evaluate the clinical efficacy and safety of baminercept, a lymphotoxin ß receptor IgG fusion protein (LTßR-Ig), for the treatment of primary Sjögren's syndrome (SS), and to explore the possible mechanisms of action of this treatment. METHODS: In this multicenter trial, 52 patients with primary SS were randomized in a 2:1 ratio to receive subcutaneous injections of 100 mg of baminercept every week for 24 weeks or matching placebo. The primary end point was the change between screening and week 24 in the stimulated whole salivary flow (SWSF) rate. Secondary end points included the European League Against Rheumatism Sjögren's Syndrome Disease Activity Index (ESSDAI), as well as measurements of select chemokines and cytokines and enumeration of peripheral blood B and T cell subsets. RESULTS: The change from baseline to week 24 in the SWSF rate was not significantly different between the baminercept and placebo treatment groups (baseline-adjusted mean change -0.01 versus 0.07 ml/minute; P = 0.332). The change in the ESSDAI during treatment was also not significantly different between the treatment groups (baseline-adjusted mean change -1.23 versus -0.15; P = 0.104). Although the incidence of adverse events was similar between the treatment groups, baminercept therapy was associated with a higher incidence of liver toxicity, including 2 serious adverse events. Baminercept also produced a significant decrease in plasma levels of CXCL13 and significant changes in the number of circulating B and T cells, consistent with its known inhibitory effects on LTßR signaling. CONCLUSION: In this trial, treatment with baminercept failed to significantly improve glandular and extraglandular disease in patients with primary SS, despite evidence from mechanistic studies showing that it blocks LTßR signaling.

Identification of a Sjögren's syndrome susceptibility locus at OAS1 that influences isoform switching, protein expression, and responsiveness to type I interferons.

Sjögren's syndrome (SS) is a common, autoimmune exocrinopathy distinguished by keratoconjunctivitis sicca and xerostomia. Patients frequently develop serious complications including lymphoma, pulmonary dysfunction, neuropathy, vasculitis, and debilitating fatigue. Dysregulation of type I interferon (IFN) pathway is a prominent feature of SS and is correlated with increased autoantibody titers and disease severity. To identify genetic determinants of IFN pathway dysregulation in SS, we performed cis-expression quantitative trait locus (eQTL) analyses focusing on differentially expressed type I IFN-inducible transcripts identified through a transcriptome profiling study. Multiple cis-eQTLs were associated with transcript levels of 2'-5'-oligoadenylate synthetase 1 (OAS1) peaking at rs10774671 (PeQTL = 6.05 × 10-14). Association of rs10774671 with SS susceptibility was identified and confirmed through meta-analysis of two independent cohorts (Pmeta = 2.59 × 10-9; odds ratio = 0.75; 95% confidence interval = 0.66-0.86). The risk allele of rs10774671 shifts splicing of OAS1 from production of the p46 isoform to multiple alternative transcripts, including p42, p48, and p44. We found that the isoforms were differentially expressed within each genotype in controls and patients with and without autoantibodies. Furthermore, our results showed that the three alternatively spliced isoforms lacked translational response to type I IFN stimulation. The p48 and p44 isoforms also had impaired protein expression governed by the 3' end of the transcripts. The SS risk allele of rs10774671 has been shown by others to be associated with reduced OAS1 enzymatic activity and ability to clear viral infections, as well as reduced responsiveness to IFN treatment. Our results establish OAS1 as a risk locus for SS and support a potential role for defective viral clearance due to altered IFN response as a genetic pathophysiological basis of this complex autoimmune disease.

The Biomarkers of Lupus Disease Study: A Bold Approach May Mitigate Interference of Background Immunosuppressants in Clinical Trials.

OBJECTIVE: Molecular medicine raised expectations for strategically targeted biologic agents in systemic lupus erythematosus (SLE), but clinical trial results have been disappointing and difficult to interpret. Most studies add investigational agents to various, often effective, standard therapy immunosuppressants used at baseline, with unknown treatment interactions. Eliminating polypharmacy in trials of active lupus remains controversial. We undertook the Biomarkers of Lupus Disease study to test withdrawal of immunosuppressants as a novel approach to rendering SLE trials interpretable. METHODS: In 41 patients with active, non-organ-threatening SLE flare (group A), temporary steroids were given while background immunosuppressants were withdrawn. Time to loss of disease suppression (time to disease flare) and safety were evaluated; standard therapy was immediately resumed when symptoms recurred. Immunologic impacts of standard therapy were studied at baseline by multiplex assay, enzyme-linked immunosorbent assay, and messenger RNA array in group A patients plus 62 additional patients donating a single sample (group B). RESULTS: Patients with lower or higher baseline disease activity had median times to flare of 71 or 45 days, respectively; 40 of 41 patients (98%) had disease flares by 6 months. All flares were treated and resolved within 6 weeks. No serious adverse events occurred from flare or infection. Type I interferon (IFN), Th17, and B lymphocyte stimulator pathways tracked together. Baseline immunosuppressants had distinct impacts on Th17 and B lymphocyte stimulator, depending on IFN signature. CONCLUSION: Trials in active, non-organ-threatening SLE can safely withdraw background treatments if patients who have disease flares are designated nonresponders and returned to standard therapy. Immunologic effects of standard therapy vary between IFN-defined subsets. These findings provide a strategy for minimizing or optimizing treatment combinations in lupus trials and clinical care.

Association of IFIH1 and pro-inflammatory mediators: Potential new clues in SLE-associated pathogenesis.

Antiviral defenses are inappropriately activated in systemic lupus erythematosus (SLE) and association between SLE and the antiviral helicase gene, IFIH1, is well established. We sought to extend the previously reported association of pathogenic soluble mediators and autoantibodies with mouse Mda5 to its human ortholog, IFIH1. To better understand the role this gene plays in human lupus, we assessed association of IFIH1 variants with soluble mediators and autoantibodies in 357 European-American SLE patients, first-degree relatives, and unrelated, unaffected healthy controls. Association between each of 135 genotyped SNPs in IFIH1 and four lupus-associated plasma mediators, IL-6, TNF-α, IFN-ß, and IP-10, were investigated via linear regression. No significant associations were found to SNPs orthologous to those identified in exon 13 of the mouse. However, outside of this region there were significant associations between IL-6 and rs76162067 (p = 0.008), as well as IP-10 and rs79711023 (p = 0.003), located in a region of IFIH1 previously shown to directly influence MDA-5 mediated IP-10 and IL-6 secretion. SLE patients and FDRs carrying the minor allele for rs79711023 demonstrated lower levels of IP-10, while only FDRs carrying the minor allele for rs76162067 demonstrated an increased level of IL-6. This would suggest that the change in IP-10 is genotypically driven, while the change in IL-6 may be reflective of SLE transition status. These data suggest that IFIH1 may contribute to SLE pathogenesis via altered inflammatory mechanisms.

Clinical and Serologic Features in Patients With Incomplete Lupus Classification Versus Systemic Lupus Erythematosus Patients and Controls.

OBJECTIVE: Incomplete lupus erythematosus (ILE) involves clinical and/or serologic manifestations consistent with but insufficient for systemic lupus erythematosus (SLE) classification. Because the nature of ILE is poorly understood and no treatment recommendations exist, we examined the clinical manifestations, medication history, and immunologic features in a diverse collection of ILE and SLE patients. METHODS: Medical records of subjects enrolled in the Lupus Family Registry and Repository were reviewed for medication history and American College of Rheumatology (ACR) classification criteria to identify ILE patients (3 ACR criteria; n = 440) and SLE patients (≥4 ACR criteria; n = 3,397). Participants completed the Connective Tissue Disease Screening Questionnaire. Anticardiolipin and plasma B lymphocyte stimulator (BLyS) were measured by enzyme-linked immunosorbent assay, antinuclear antibodies (ANAs) by indirect immunofluorescence, and 13 autoantibodies by bead-based assays. RESULTS: On average, ILE patients were older than SLE patients (46.2 years versus 42.0 years; P < 0.0001), and fewer ILE patients were African American (23.9% versus 32.2%; P < 0.001). ILE patients exhibited fewer autoantibody specificities than SLE patients (1.3 versus 2.6; P < 0.0001) and were less likely to have ANA titers ≥1:1,080 (10.5% versus 19.5%; P < 0.0001). BLyS levels were intermediate in ILE patients (controls < ILE; P = 0.016; ILE < SLE; P = 0.008). Pericarditis, renal, or neurologic manifestations occurred in 12.5% of ILE patients and were associated with non-European American race/ethnicity (P = 0.012). Hydroxychloroquine use increased over time, but was less frequent in ILE than SLE patients (65.2% versus 83.1%; P < 0.0001). CONCLUSION: Although usually characterized by milder symptoms, ILE manifestations may require immunomodulatory treatments. Longitudinal studies are necessary to understand how ILE affects organ damage and future SLE risk, and to delineate molecular pathways unique to ILE.

Human effector B lymphocytes express ARID3a and secrete interferon alpha.

Previously, we determined that enhanced disease activity in patients with systemic lupus erythematosus (SLE) was associated with dramatic increases in numbers of B lymphocytes expressing the transcription factor ARID3a. Our data now indicate ARID3a is important for interferon alpha (IFNa) expression and show a strong association between ARID3a expression and transcription of genes associated with lupus IFN signatures. Furthermore, both ARID3a and IFNa production were elicited in healthy control B cells upon stimulation with the TLR 9 agonist, CpG. Importantly, secretion of IFNa from ARID3a+ healthy B lymphocytes stimulated increased IFNa production in plasmacytoid dendritic cells. These data identify ARID3a+ B cells as a novel type of effector B cell, and link ARID3a expression in B lymphocytes to IFN-associated inflammatory responses in SLE.