Faculty Bibliography

Despite rapid accumulation of knowledge about complex immune dysregulation in systemic lupus erythematosus (SLE) and major primary lupus syndromes, and a plethora of promising new treatments reaching preclinical and early clinical studies, advanced-phase trials of new biologic agents have repeatedly failed to achieve their clinical end points. It is possible that none of these agents work, but the accuracy of this suggestion is as unclear as the case for efficacy, owing to issues in the design of studies and the opacity of the data that have resulted. Disease heterogeneity and complexity might be a hurdle that is simply too high to overcome by existing methodological approaches, and the way forward to interpretable trial results remains unclear. Nonetheless, well-characterized patterns of immune pathology are shared by substantial subsets of patients, and selective targeting of one or more relevant immune system molecules seems to offer the promise of safer and more effective treatments. Evolution dictates a more personalized approach to therapy and trial design, but this option seems challenging in the current economic, regulatory and scientific environment. This Review addresses these concerns by considering the progress of some of the investigational treatments targeting key physiological abnormalities in lupus.

Objective. Accurate assessment of lupus flares is critical but problematic in clinical trials. This study examined the impact of modifications to the classic Safety of Estrogens in Lupus Erythematosus National Assessment (SELENA)-SLEDAI flare index (cSFI).Methods. Ninety-one SLE patient records were evaluated at two visits at which the SLEDAI and BILAG had been scored prospectively. The cSFI was compared with an experimental version (eSFI) that eliminated medication criteria and separated the mild/moderate flare category into its components by clinical judgement based on records. The revised SFI (SFI-R) and some physician's global assessments (PGAs) were also scored using chart notes.Results. eSFI-rated moderate flares had higher PGA and BILAG scores than those rated as mild. When medication criteria were excluded, 42 of 55 cSFI severe flares and 15 of 49 mild/moderate flares were downgraded in severity. Comparing flares that remained severe with those that were downgraded, disease activity was higher by PGA (P < 0.001), SLEDAI (P < 0.001), BILAG (P < 0.001), number of active BILAG organs (P < 0.04) and flaring SFI-R organs (P < 0.01). PGA (P < 0.001) and the number of SFI-R domains flaring (P < 0.001) were higher in mild/moderate eSFI flares than in those that were downgraded. Twenty-one of 83 (25%) medication changes occurred with no flare. Forty-six of 52 (88%) medication changes defining severe flare by cSFI involved patients rated by physicians with no, mild or moderate flares.Conclusion. A deconstructed flare index improves the discrimination of mild from moderate flares and selects more ill patients with true clinical worsening for each category of flare.

OBJECTIVE: To evaluate the efficacy/safety of belimumab plus standard therapy in patients (n = 449) with active systemic lupus erythematosus (SLE) treated up to 7 years (n = 177 currently ongoing). METHODS: Patients (n = 345) who completed a double-blind, placebo-controlled, 52-week study of belimumab 1, 4, or 10 mg/kg and 24-week extension of belimumab (placebo switched to 10 mg/kg; belimumab same dose or switched to 10 mg/kg) could receive belimumab 10 mg/kg in an open-label continuation study (n = 296). Disease activity was analyzed in patients with active SLE at baseline of the initial study. Biomarker and SLE medication changes were evaluated, and adverse events (AE) were monitored throughout the study. RESULTS: Total belimumab exposure over 7 years (double-blind and open-label periods): 1746 patient-years. SLE Responder Index (SRI) response rates at Week 52 in autoantibody-positive patients: placebo, 29%; belimumab, 46% (p < 0.05). In the continuation study, 57% of auto-antibody-positive patients had an SRI response by Year 2 and 65% by Year 7; severe flares occurred in 19% with placebo and 17% with belimumab during the first year, with the annual rate declining to 2%-9% during years 2-7. Anti-dsDNA autoantibodies in patients positive for them at baseline had a progressive decline of 40%-60% from baseline over 2-7 years with belimumab. Corticosteroid use decreased over time with >/= 50-55% reduction in median dose during years 5-7. Serious and overall annual AE rates, including infections, were generally stable or decreased during 7-year treatment. CONCLUSION: Disease control and safety profile were maintained in patients with active SLE taking belimumab plus standard therapy for up to 7 years. [ClinicalTrials.gov numbers: NCT00071487 and NCT00583362].

INTRODUCTION/BACKGROUND:Systemic lupus erythematosus (SLE) is characterized by impaired efferocytosis and aberrant activation of innate immunity. We asked if shedding of MER receptor tyrosine kinase (MerTK) and AXL into soluble (s) ectodomains was related to immunological and clinical aspects of SLE. METHODS:Levels of sMER and sAXL in the plasma of 107 SLE patients and 45 matched controls were measured by ELISA. In 40 consecutive SLE patients, we examined potential correlations between either sMER or sAXL and plasma levels of sCD163, a marker of M2 activation. All three soluble receptors were measured in supernatants of monocytes/macrophages cultured in various immunological conditions. Membrane expression of MerTK, AXL and CD163 was assessed by flow cytometry. RESULTS:Both sMER and sAXL were associated with anti-chromatin and anti-phospholipid autoantibodies, and with hematological and renal involvement. However, sMER and sAXL did not significantly correlate with each other; sAXL correlated with growth arrest-specific 6 (Gas6), whereas sMER correlated with reduced free protein S (PROS) levels. Only sMER showed significant associations with lupus-specific anti-dsDNA, anti-Sm, anti-ribonucleoprotein (anti-RNP) and anti-Ro60 autoantibodies. Strong correlations with disease activity indices (Systemic Lupus Erythematosus Disease Activity Index (SLEDAI), complement reduction, titer of circulating anti-dsDNA) were found for sMER, not for sAXL. Patients with active SLEDAI, nephritis, anti-dsDNA and anti-Ro60 positivity showed higher levels of sMER compared to controls. Levels of sMER, not sAXL, correlated with sCD163 levels, and these correlated with SLEDAI. Production of sMER and sCD163 occurred under “M2c” polarizing conditions, whereas sAXL was released upon type-I IFN exposure. CONCLUSIONS:Alterations in homeostasis of anti-inflammatory and efferocytic “M2c” monocytes/macrophages may have a role in immunopathogenesis of SLE.

BACKGROUND: The metabolic syndrome (MetS) may contribute to increased cardiovascular risk in systemic lupus erythematosus (SLE). We aimed to examine the association of demographic factors, lupus phenotype and therapy exposure with the presence of MetS. METHODS: The Systemic Lupus International Collaborating Clinics Registry for Atherosclerosis inception cohort enrolled recently diagnosed (<15 months) SLE patients from 30 centres across 11 countries from 2000. Clinical, laboratory and therapeutic data were collected according to a standardised protocol. MetS was defined according to the 2009 consensus statement from the International Diabetes Federation. Univariate and backward stepwise multivariate logistic regression were used to assess the relationship of individual variables with MetS. RESULTS: We studied 1686 patients, of whom 1494 (86.6%) had sufficient data to determine their MetS status. The mean (SD) age at enrolment and disease duration was 35.2 years (13.4) and 24.1 weeks (18.0), respectively. MetS was present at the enrolment visit in 239 (16%). In backward stepwise multivariable regression analysis, higher daily average prednisolone dose (mg) (OR 1.02, 95% CI 1.00 to 1.03), older age (years) (OR 1.04, 95% CI 1.03 to 1.06), Korean (OR 6.33, 95% CI 3.68 to 10.86) and Hispanic (OR 6.2, 95% CI 3.78 to 10.12) ethnicity, current renal disease (OR 1.79, 95% CI 1.14 to 2.80) and immunosuppressant use (OR 1.81, 95% CI 1.18 to 2.78) were associated with MetS. CONCLUSIONS: Renal lupus, higher corticosteroid doses, Korean and Hispanic ethnicity are associated with MetS in SLE patients. Balancing disease control and minimising corticosteroid exposure should therefore be at the forefront of personalised treatment decisions in SLE patients.

OBJECTIVE: To evaluate the efficacy/safety of belimumab in patients with rheumatoid arthritis (RA). METHODS: Patients fulfilling American College of Rheumatology (ACR) criteria for RA for >/= 1 year who had at least moderate disease activity while receiving stable disease-modifying antirheumatic drug (DMARD) therapy and failed >/= 1 DMARD were randomly assigned to placebo or belimumab 1, 4, or 10 mg/kg, administered intravenously on Days 1, 14, and 28, and then every 4 weeks for 24 weeks (n = 283). This was followed by an optional 24-week extension (n = 237) in which all patients received belimumab. Primary efficacy endpoint was the Week 24 ACR20 response. RESULTS: Week 24 ACR20 responses with placebo and belimumab 1, 4, and 10 mg/kg were 15.9%, 34.7% (p = 0.010), 25.4% (p = 0.168), and 28.2% (p = 0.080), respectively. Patients taking any belimumab dose who continued with belimumab in the open-label extension had an ACR20 response of 41% at 48 weeks. A similar ACR20 response (42%) at 48 weeks was seen in patients taking placebo who switched in the extension to belimumab 10 mg/kg. Greater response rates were observed in patients who at baseline were rheumatoid factor-positive, anticitrullinated protein antibody-positive, or tumor necrosis factor inhibitor-naive, or had elevated C-reactive protein levels, Disease Activity Score 28 > 5.1, or low B lymphocyte stimulator levels (< 0.858 ng/ml). Adverse event rates were similar across treatment groups. CONCLUSION: In this phase II trial, belimumab demonstrated efficacy and was generally well tolerated in patients with RA who had failed previous therapies. [ClinicalTrials.gov identifier NCT00071812].

OBJECTIVES: The Xq28 region containing IRAK1 and MECP2 has been identified as a risk locus for systemic lupus erythematosus (SLE) in previous genetic association studies. However, due to the strong linkage disequilibrium between IRAK1 and MECP2, it remains unclear which gene is affected by the underlying causal variant(s) conferring risk of SLE. METHODS: We fine-mapped >/=136 SNPs in a approximately 227 kb region on Xq28, containing IRAK1, MECP2 and seven adjacent genes (L1CAM, AVPR2, ARHGAP4, NAA10, RENBP, HCFC1 and TMEM187), for association with SLE in 15 783 case-control subjects derived from four different ancestral groups. RESULTS: Multiple SNPs showed strong association with SLE in European Americans, Asians and Hispanics at p<5x10(-8) with consistent association in subjects with African ancestry. Of these, six SNPs located in the TMEM187-IRAK1-MECP2 region captured the underlying causal variant(s) residing in a common risk haplotype shared by all four ancestral groups. Among them, rs1059702 best explained the Xq28 association signals in conditional testings and exhibited the strongest p value in transancestral meta-analysis (p(meta )= 1.3x10(-27), OR=1.43), and thus was considered to be the most likely causal variant. The risk allele of rs1059702 results in the amino acid substitution S196F in IRAK1 and had previously been shown to increase NF-kappaB activity in vitro. We also found that the homozygous risk genotype of rs1059702 was associated with lower mRNA levels of MECP2, but not IRAK1, in SLE patients (p=0.0012) and healthy controls (p=0.0064). CONCLUSIONS: These data suggest contributions of both IRAK1 and MECP2 to SLE susceptibility.

Accurately measuring lupus disease activity has been a demanding and still unresolved task, considering the complex multisystem nature of the disease and its variability over time and between patients. Various available tools for measurement of lupus disease activity may detect clinical improvement and/or deterioration and can be global or organ-focused. Several measures have demonstrated validity, reliability, and sensitivity to change in observational studies, and some were found useful in randomized controlled trials. Evaluation of their content and metric properties and critical review of their strengths and weaknesses facilitates selection of the appropriate tool according to the outcome of interest, and forms the basis for their optimization. In this review, we highlight recent progress in lupus disease activity measures and point to future directions in this field, with a focus on novel composite measurements derived by combining outcome measures in ways that might compensate for their individual deficiencies.

Systemic lupus erythematosus (SLE) is an inflammatory autoimmune disease with a strong genetic component. African-Americans (AA) are at increased risk of SLE, but the genetic basis of this risk is largely unknown. To identify causal variants in SLE loci in AA, we performed admixture mapping followed by fine mapping in AA and European-Americans (EA). Through genome-wide admixture mapping in AA, we identified a strong SLE susceptibility locus at 2q22-24 (LOD=6.28), and the admixture signal is associated with the European ancestry (ancestry risk ratio ~1.5). Large-scale genotypic analysis on 19,726 individuals of African and European ancestry revealed three independently associated variants in the IFIH1 gene: an intronic variant, rs13023380 [P(meta) = 5.20x10(-14); odds ratio, 95% confidence interval = 0.82 (0.78-0.87)], and two missense variants, rs1990760 (Ala946Thr) [P(meta) = 3.08x10(-7); 0.88 (0.84-0.93)] and rs10930046 (Arg460His) [P(dom) = 1.16x10(-8); 0.70 (0.62-0.79)]. Both missense variants produced dramatic phenotypic changes in apoptosis and inflammation-related gene expression. We experimentally validated function of the intronic SNP by DNA electrophoresis, protein identification, and in vitro protein binding assays. DNA carrying the intronic risk allele rs13023380 showed reduced binding efficiency to a cellular protein complex including nucleolin and lupus autoantigen Ku70/80, and showed reduced transcriptional activity in vivo. Thus, in SLE patients, genetic susceptibility could create a biochemical imbalance that dysregulates nucleolin, Ku70/80, or other nucleic acid regulatory proteins. This could promote antibody hypermutation and auto-antibody generation, further destabilizing the cellular network. Together with molecular modeling, our results establish a distinct role for IFIH1 in apoptosis, inflammation, and autoantibody production, and explain the molecular basis of these three risk alleles for SLE pathogenesis.