Faculty Bibliography

A classic T-cell phenotype in systemic lupus erythematosus (SLE) is the downregulation and replacement of the CD3zeta chain that alters T-cell receptor signaling. However, genetic associations with SLE in the human CD247 locus that encodes CD3zeta are not well established and require replication in independent cohorts. Our aim was therefore to examine, localize and validate CD247-SLE association in a large multiethnic population. We typed 44 contiguous CD247 single-nucleotide polymorphisms (SNPs) in 8922 SLE patients and 8077 controls from four ethnically distinct populations. The strongest associations were found in the Asian population (11 SNPs in intron 1, 4.99 x 10(-4) < P < 4.15 x 10(-2)), where we further identified a five-marker haplotype (rs12141731-rs2949655-rs16859085-rs12144621-rs858554; G-G-A-G-A; P(hap) = 2.12 x 10(-5)) that exceeded the most associated single SNP rs858554 (minor allele frequency in controls = 13%; P = 4.99 x 10(-4), odds ratio = 1.32) in significance. Imputation and subsequent association analysis showed evidence of association (P < 0.05) at 27 additional SNPs within intron 1. Cross-ethnic meta-analysis, assuming an additive genetic model adjusted for population proportions, showed five SNPs with significant P-values (1.40 x 10(-3) < P< 3.97 x 10(-2)), with one (rs704848) remaining significant after Bonferroni correction (P(meta) = 2.66 x 10(-2)). Our study independently confirms and extends the association of SLE with CD247, which is shared by various autoimmune disorders and supports a common T-cell-mediated mechanism.

Although hematopoietic stem/progenitor cells (HSPCs) are used for transplantation, characterization of the multiple subsets within this population in humans has lagged behind similar studies in mice. We found that expression of the DNA-binding protein, ARID3a, in mouse stem cells was important for normal development of hematopoietic lineages; however, progenitors expressing ARID3a in humans have not been defined. We previously showed increased numbers of ARID3a(+) B cells in nearly half of systemic lupus erythematosus (SLE) patients, and total numbers of ARID3a(+) B cells were associated with increased disease severity. Because expression of ARID3a in those SLE patients occurred throughout all B cell subsets, we hypothesized that ARID3a expression in patient HSPCs might also be increased relative to expression in healthy controls. Our data now show that ARID3a expression is not limited to any defined subset of HSPCs in either healthy controls or SLE patients. Numbers of ARID3a(+) HSPCs in SLE patients were increased over numbers of ARID3a(+) cells in healthy controls. Although all SLE-derived HSPCs exhibited poor colony formation in vitro compared with controls, SLE HSPCs with high numbers of ARID3a(+) cells yielded increased numbers of cells expressing the early progenitor marker, CD34. SLE HSPCs with high numbers of ARID3a(+) cells also more readily generated autoantibody-producing cells than HSPCs with lower levels of ARID3a in a humanized mouse model. These data reveal new functions for ARID3a in early hematopoiesis and suggest that knowledge regarding ARID3a levels in HSPCs could be informative for applications requiring transplantation of those cells.

Exploiting genotyping, DNA sequencing, imputation, and trans-ancestral mapping, we used Bayesian and frequentist approaches to model the IRF5-TNPO3 locus association, now implicated in two immunotherapies and seven autoimmune diseases. Specifically, in systemic lupus erythematosus (SLE) we resolved separate associations in the IRF5 promoter (all ancestries) and with an extended European haplotype. We captured 3,230 IRF5-TNPO3 high quality, common variants across five ethnicities in 8,395 SLE cases and 7,367 controls. The genetic effect from the IRF5 promoter can be explained by any one of four variants in 5.7 kb (p-valuemeta=6x10-49; OR=1.38-1.97). The second genetic effect spanned an 85.5 kb, 24 variant haplotype that included the genes IRF5 and TNPO3 (p-valuesEU=10-27-10-32, OR=1.7-1.81). Many variants at the IRF5 locus with previously assigned biological function are not members of either final credible set of potential causal variants identified herein. In addition to the known biologically functional variants, we demonstrated that the risk allele of rs4728142, a variant in the promoter among the lowest frequentist probability and highest Bayesian posterior probability, was correlated with IRF5 expression and differentially binds the transcription factor ZBTB3. Our analytical strategy provides a novel framework for future studies aimed at dissecting etiological genetic effects. Finally, both SLE elements of the statistical model appear to operate in Sjogren's syndrome and systemic sclerosis while only the IRF5-TNPO3 gene-spanning haplotype is associated in primary biliary cirrhosis, demonstrating the nuance of similarity and difference in autoimmune disease risk mechanisms at IRF5-TNPO3.

Objective: To estimate the early prevalence of various electrocardiographic (ECG) abnormalities in patients with SLE and to evaluate possible associations between repolarization changes (increased corrected QT, QTc, and QT dispersion, QTd) and clinical and laboratory variables, including the anti-Ro/SSA level and specificity (52 or 60KDa). Methods: We studied adult SLE patients from 19 centers participating in the Systemic Lupus International Collaborating Clinics (SLICC) Inception Registry. Demographics, disease activity (SLEDAI-2K), disease damage (SLICC/ACR DI), and laboratory data from the baseline or first follow-up visit were assessed. Multivariate logistic and linear regression models were used to asses for any cross-sectional associations between anti-Ro/SSA and ECG repolarization abnormalities. Results: For the 779 patients included, mean age (SD) was 35.6 years (13.8), 88.4% were women, and mean disease duration was 10.5 months (14.4). Mean SLEDAI-2K was 5.4 (5.6) and mean SLICC/ACR DI was 0.5 (1.0). ECG abnormalities were frequent and included non-specific ST-T changes (30.9%), possible left ventricular hypertrophy (5.4%) and supraventricular arrhythmias (1.3%). A QTc >/= 440ms was found in 15.3%, while QTc >/= 460ms was found in 5.3%. Mean (SD) QTd was 34.2ms (14.7) and QTd >/= 40ms was frequent (38.1%). Neither the specificity, nor the level of anti-Ro/SSA was associated with QTc duration or QTd, although confidence intervals were wide. Total DI was significantly associated with a QTc interval exceeding 440 ms (OR 1.38 95% CI 1.06, 1.79). Conclusion: A substantial proportion of recent-onset SLE patients exhibit repolarization abnormalities although severe abnormalities were rare. (c) 2014 American College of Rheumatology.

OBJECTIVE: Anti-C1q has been associated with systemic lupus erythematosus (SLE) and lupus nephritis in previous studies. We studied anti-C1q specificity for SLE (vs rheumatic disease controls) and the association with SLE manifestations in an international multicenter study. METHODS: Information and blood samples were obtained in a cross-sectional study from patients with SLE (n = 308) and other rheumatologic diseases (n = 389) from 25 clinical sites (84% female, 68% Caucasian, 17% African descent, 8% Asian, 7% other). IgG anti-C1q against the collagen-like region was measured by ELISA. RESULTS: Prevalence of anti-C1q was 28% (86/308) in patients with SLE and 13% (49/389) in controls (OR = 2.7, 95% CI: 1.8-4, p < 0.001). Anti-C1q was associated with proteinuria (OR = 3.0, 95% CI: 1.7-5.1, p < 0.001), red cell casts (OR = 2.6, 95% CI: 1.2-5.4, p = 0.015), anti-dsDNA (OR = 3.4, 95% CI: 1.9-6.1, p < 0.001) and anti-Smith (OR = 2.8, 95% CI: 1.5-5.0, p = 0.01). Anti-C1q was independently associated with renal involvement after adjustment for demographics, ANA, anti-dsDNA and low complement (OR = 2.3, 95% CI: 1.3-4.2, p < 0.01). Simultaneously positive anti-C1q, anti-dsDNA and low complement was strongly associated with renal involvement (OR = 14.9, 95% CI: 5.8-38.4, p < 0.01). CONCLUSIONS: Anti-C1q was more common in patients with SLE and those of Asian race/ethnicity. We confirmed a significant association of anti-C1q with renal involvement, independent of demographics and other serologies. Anti-C1q in combination with anti-dsDNA and low complement was the strongest serological association with renal involvement. These data support the usefulness of anti-C1q in SLE, especially in lupus nephritis.

This review describes eight 'great ideas' regarding bench-to-bedside considerations in systemic lupus erythematosus (SLE) presented at the second international LUPUS meeting in Quebec, September 2014. The topics included: correcting the impaired clearance of apoptotic fragments; optimisation of clinical trial design: the PERFECT (Pre Evaluation Reducing Frighteningly Elevated Coverable Targets) study; lipidomics and metabolomics in SLE; importance of the inflammasome; identification and treatment of asymptomatic autoimmunity: prevention of SLE; combining low doses of hydroxychloroquine and quinacrine for long-term maintenance therapy of SLE; reducing emergency room visits and the critical relevance of the autoantigen.

OBJECTIVE:Systemic lupus erythematosus (SLE) is a complex autoimmune disease characterised by heterogeneous clinical manifestations, autoantibody production and epigenetic dysregulation in T cells. We sought to investigate the epigenetic contribution to the development of cutaneous manifestations in SLE. METHODS:We performed genome-wide DNA methylation analyses in patients with SLE stratified by a history of malar rash, discoid rash or neither cutaneous manifestation, and age, sex and ethnicity matched healthy controls. We characterised differentially methylated regions (DMRs) in naïve CD4+ T cells unique to each disease subset, and assessed functional relationships between DMRs using bioinformatic approaches. RESULTS:We identified 36 and 37 unique DMRs that contribute to the epigenetic susceptibility to malar rash and discoid rash, respectively. These DMRs were primarily localised to genes mediating cell proliferation and apoptosis. Hypomethylation of MIR886 and TRIM69, and hypermethylation of RNF39 were specific to patients with SLE with a history of malar rash. Hypomethylation of the cytoskeleton-related gene RHOJ was specific to patients with SLE with a history of discoid rash. In addition, discoid rash-specific hypomethylated DMRs were found in genes involved in antigen-processing and presentation such as TAP1 and PSMB8. Network analyses showed that DMRs in patients with SLE with but not without a history of cutaneous manifestations are associated with TAP-dependent processing and major histocompatibility-class I antigen cross-presentation (p=3.66×10(-18) in malar rash, and 3.67×10(-13) in discoid rash). CONCLUSIONS:We characterised DNA methylation changes in naïve CD4+ T cells specific to malar rash and discoid rash in patients with SLE. These data suggest unique epigenetic susceptibility loci that predispose to or are associated with the development of cutaneous manifestations in SLE.

OBJECTIVE:Current disease activity measures for systemic lupus erythematosus (SLE) are difficult to score or interpret and problematic for use in clinical practice. Lupus Foundation of America (LFA)-Rapid Evaluation of Activity in Lupus (REAL) is a pilot application composed of anchored visual analogue scores (0-100 mm each) for each organ affected by lupus. This study evaluated the use of LFA-REAL in capturing SLE disease activity. METHODS:In a preliminary test of LFA-REAL, this simplified, organ-based system was compared with the most widely used outcome measures in clinical trials, the British Isles Lupus Assessment Group 2004 Index (BILAG), the SLE Disease Activity Index (SLEDAI) and the Safety of Estrogens in Lupus Erythematosus National Assessment (SELENA) SLEDAI Physician's Global Assessment (SS-PGA). The level of agreement was analysed using Spearman rank correlations. RESULTS:91 patients with SLE with mild to severe disease activity were evaluated, their median SLEDAI score was 4.0 (range 0-28) and BILAG score 8.0 (0-32). The median SS-PGA was 38 mm (4-92) versus the total REAL 50 mm (0-268), which expands in range by additive organ scores. Thirty-three patients had moderate to severe disease activity (≥1.5 on SS-PGA landmarks). The median SS-PGA score of this group was 66 mm (50-92) versus median REAL score of 100 mm (59-268), confirming ability to detect a wider distribution of scores at higher disease activity. Total REAL correlated with SLEDAI, BILAG and SS-PGA (correlation coefficient=0.816, 0.933 and 0.903, respectively; p<0.001 for all). Individual LFA-REAL organ scores for musculoskeletal and mucocutaneous also correlated with corresponding BILAG domain scores (correlation coefficient=0.925 and 0.934, p<0.001). CONCLUSIONS:In this preliminary exercise, there were strong correlations between LFA-REAL and validated lupus disease activity indices. Further development may be valuable for consistent scoring in clinical trials, grading optimal assessment of change in disease activity and reliable monitoring of patients in practice.