Infections in Vasculitis: Can We Create an Epidemic of Change?

In the article entitled "Prevalence, Predictors, and Prognosis of Serious Infections in Takayasu Arteritis: A Cohort Study" by Misra and colleagues in this issue of The Journal of Rheumatology, the authors examine the incidence of serious infections in a Takayasu arteritis (TA) patient cohort; analyze associated demographic, clinical, angiographic, and treatment-related factors; and evaluate their impact on serious infections and mortality in TA.1 They found that serious infections in patients with TA were prevalent, occurring in one-sixth of their cohort, with pneumonia (38%) and tuberculosis (TB; 24%) as the most common infections identified.1.

Safety and tolerability of hydroxychloroquine in health care workers and first responders for the prevention of COVID-19: WHIP COVID-19 Study.

BACKGROUND: Health care workers (HCW) are among the highest risk groups for acquisition of COVID-19 because of occupational exposures. The WHIP COVID-19 Study aimed to evaluate the safety and efficacy of hydroxychloroquine (HCQ) as chemoprophylaxis for SARS-CoV-2 infection in this population. METHODS: HCW, first responders, and other occupationally high-risk participants were enrolled in a randomized, placebo-controlled clinical study of HCQ from April to October 2020. The trial compared daily versus weekly HCQ with placebo and with a prospective cohort on HCQ for autoimmune diseases. Participants were followed for 8 weeks. Serology or a positive polymerase chain reaction test was used to determine laboratory confirmed clinical cases. RESULTS: A total of 624 participants were randomized to placebo (n = 200), weekly HCQ (n = 201), daily HCQ (n = 197). For the primary safety end point, 279 (44.7%) participants experienced adverse event (AE) level II or lower (total AEs n = 589), similar rates in all randomized groups (P = .188) with no hospitalizations or interventions required. Only 4 laboratory confirmed COVID-19 cases occurred, with 2 in the placebo arm and one in each HCQ randomized arm. CONCLUSIONS: This randomized placebo-controlled trial was able to demonstrate the safety of HCQ outpatient chemoprophylaxis in high-risk groups against COVID-19. Future studies of chemoprophylaxis for SARS-CoV-2 are needed as the epidemic continues worldwide.

Phase III/IV, Randomized, Fifty-Two-Week Study of the Efficacy and Safety of Belimumab in Patients of Black African Ancestry With Systemic Lupus Erythematosus.

OBJECTIVE: Enrollment of patients of Black African ancestry with systemic lupus erythematosus (SLE) in phase II and phase III of the belimumab trials was not reflective of the racial distribution observed in the lupus population. This study was undertaken to assess the efficacy and safety of intravenous (IV) belimumab plus standard therapy in patients of self-identified Black race. METHODS: EMBRACE (GSK Study BEL115471; ClinicalTrials.gov identifier: NCT01632241) was a 52-week multicenter, double-blind, placebo-controlled trial in adults of self-identified Black race with active SLE who received monthly belimumab 10 mg/kg IV, or placebo, plus standard therapy. The optional 26-week open-label extension phase included patients who completed the double-blind phase. The primary end point of the study was SLE Responder Index (SRI) response rate at week 52 with modified proteinuria scoring adapted from the SLE Disease Activity Index 2000 (SLEDAI-2K) (SRI-SLEDAI-2K). Key secondary end points included SRI response rate at week 52, time to first severe SLE flare, and reductions in prednisone dose. RESULTS: The modified intent-to-treat population comprised 448 patients, of whom 96.9% were women and the mean ± SD age was 38.8 ± 11.42 years. The primary end point (improvement in the SRI-SLEDAI-2K response rate at week 52) was not achieved (belimumab 48.7%, placebo 41.6%; odds ratio 1.40 [95% confidence interval 0.93, 2.11], P = 0.1068); however, numerical improvements favoring belimumab were observed, in which the SRI-SLEDAI-2K response rates were higher in those who received belimumab compared with those who received placebo, especially in patients with SLE who had high disease activity or renal manifestations at baseline. The safety profile of belimumab was generally consistent with that observed in previous SLE trials. Adverse events were the primary reasons for double-blind phase withdrawals (belimumab 5.4%, placebo 6.7%). CONCLUSION: The primary end point of this study was not achieved, but improvement with belimumab versus placebo was observed, suggesting that belimumab remains a suitable treatment option for SLE management in patients of Black African ancestry.

The role of tocilizumab therapy in critically ill patients with severe acute respiratory syndrome coronavirus 2.

CONTEXT: Tocilizumab (TCZ), an interleukin-6 (IL-6) receptor antagonist, has been approved for use in rheumatoid arthritis and cytokine storm syndrome (CSS) associated with chimeric antigen receptor T cells treatment. Although TCZ is currently utilized in the treatment of critically ill coronavirus 2019 (COVID-19) patients, data on survival impact is minimal. OBJECTIVES: To assess the mortality rate of patients presenting with COVID-19 who received TCZ for suspected CSS. METHODS: This retrospective cohort study was conducted at Henry Ford Health System between March 10, 2020 and May 18, 2020. Data collection began in May 2020 and was completed in June 2020. Patients included in the study required hospital admission and had positive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) polymerase chain reaction on nasopharyngeal swab. Eligibility criteria to receive TCZ, per hospital protocol, included any of the following: persistent fever, defined as 38.0 °C for at least 6 hours; a diagnosis of the acute respiratory distress syndrome (ARDS); serum ferritin ≥1,000 (ng/mL) or doubling within 24 hours; D-Dimer ≥ 5 (mg/L); serum lactate dehydrogenase ≥500 (IU/L); or interlukin-6 level ≥5 times the upper limit of normal. Dosing was initially determined by weight, then changed to a fixed 400 mg per hospital protocol. A comparator cohort was created from patients with COVID-19 and ARDS who did not receive TCZ. Patient survival was analyzed using the Kaplan-Meier method and compared by log rank test. A multivariable cox regression was applied to evaluate the association between TCZ and mortality. RESULTS: One hundred and thirty patients were evaluated in the study, 54 (41.5%) of whom received TCZ. Patients who received TCZ were younger (mean age, 63.8 vs. 69.4 years; p=0.0083) and had higher body mass indices (mean, 33.9 vs. 30.4; p=0.005). Of the comorbid conditions evaluated, heart disease was more common in the comparator group than the TCZ group (27 patients [35.5%] vs. 10 patients [18.5%]; p=0.034). A Kaplan-Meier survival curve demonstrated no difference in survival between TCZ and comparator patients (log rank p=0.495). In the multivariable Cox regression model for mortality at 30 days, treatment with TCZ was not associated with decreased mortality (hazard ratio, 1.1; 95% confidence interval, 0.53-2.3; p=0.77). Lower mean C-reactive protein (CRP) levels were demonstrated within 48 hours of disposition in the TCZ group (mean TCZ, 4.9 vs. mean comparator, 13.0; p=<0.0001). CONCLUSIONS: In this cohort study, no difference in survival was observed in critically ill patients treated with TCZ.

Subclinical CMV viremia is associated with increased nosocomial infections and prolonged hospitalization in patients with systemic autoimmune diseases.

OBJECTIVE: Subclinical cytomegalovirus (CMV) viremia has been associated with other infections, prolonged hospitalization, and mortality in select immunosuppressed populations. We examined the incidence and outcomes of subclinical CMV viremia in hospitalized patients with systemic autoimmune diseases (AD) [systemic lupus erythematosus (SLE) or anti-neutrophil cytoplasmic antibody-associated vasculitis (AAV)] using a highly sensitive CMV assay. METHODS: Prospectively collected samples were obtained from AD hospitalized patients at study entry with a second sample collected 1 week later or at hospital discharge. Controls included age- and gender- matched inpatients without AD and outpatients with AD. All samples were tested in batch using the Abbott RealTime CMV for investigational use assay (RT assay), with a LLOD (LLOQ) at 21 IU/mL (32 IU/mL). RESULTS: Twenty-three inpatients (10 SLE, 8 AAV, 5 controls), and 31 outpatient controls were recruited. Subclinical CMV viremia was found in 61% (11/18) of inpatient AD subjects, 3% (1/31) of outpatient AD subjects, and in none of the five inpatient controls (p < 0.001). CMV viremia was associated with increased median length of ICU stay (13 vs. 4 days, p = 0.033), hospital stay (17 vs. 9 days, p = 0.014) and increased nosocomial infections (7 vs. 1, p = 0.007). CMV viremia was not associated with overall severity of illness nor with disease-specific activity or damage. CONCLUSION: Over one-half of hospitalized AD patients in our cohort had detectable CMV viremia, which was associated with increased length of hospital stay and nosocomial infections. These data suggest that further study of the immunomodulatory effects of subclinical CMV viremia in AD is warranted.

Mortality and adverse events of special interest with intravenous belimumab for adults with active, autoantibody-positive systemic lupus erythematosus (BASE): a multicentre, double-blind, randomised, placebo-controlled, phase 4 trial.

BACKGROUND: Belimumab is approved for the treatment of active systemic lupus erythematosus (SLE). Although clinical trials showed a favourable benefit-risk profile, numerical differences in the incidence of mortality and adverse events of special interest (AESIs) have been reported. We assessed the frequency of these events in patients with SLE receiving belimumab or placebo plus standard therapy. METHODS: BASE was a double-blind, randomised, placebo-controlled, phase 4 trial done in 33 countries. Adults with active SLE were randomly assigned (1:1) to receive intravenous belimumab (10 mg/kg) or placebo, plus standard therapy, for 48 weeks. The primary endpoints were incidences of all-cause mortality and AESIs during the on-treatment period (first-to-last study drug dose + 28 days). Safety analyses were done in the as-treated population (patients grouped by actual treatment received >50% of the time). This study was registered with ClinicalTrials.gov (NCT01705977). FINDINGS: Between Nov 27, 2012, and July 28, 2017, we randomly assigned 4018 patients. The as-treated population included 2002 patients in the belimumab group versus 2001 in the placebo group. Ten (0·50%) patients in the belimumab group died versus eight (0·40%) in the placebo group (difference 0·10%, 95% CI -0·31 to 0·51). Incidences were similar in the belimumab and placebo groups for serious infections (75 [3·75%] of 2002 vs 82 [4·10%] of 2001; difference -0·35%, 95% CI -1·55 to 0·85), opportunistic infections and other infections of interest (36 [1·80%] vs 50 [2·50%]; -0·70%, -1·60 to 0·20), non-melanoma skin cancers (4 [0·20%] vs 3 [0·15%]; 0·05%, -0·21 to 0·31) and other malignancies (5 [0·25%] vs 5 [0·25%]; 0·00%, -0·31 to 0·31). A higher proportion of patients in the belimumab group than in the placebo group had infusion and hypersensitivity reactions (8 [0·40%] vs 2 [0·10%]; 0·30%, -0·01 to 0·61), serious depression (7 [0·35%] vs 1 [0·05%]; 0·30%, 0·02 to 0·58), treatment-emergent suicidality (28 [1·42%] of 1972 patients vs 23 [1·16%] of 1986; 0·26%, -0·44 to 0·96), and sponsor-adjudicated serious suicide or self-injury (15 [0·75%] of 1972 patients vs 5 [0·25%] of 1986; post hoc difference 0·50%, 0·06 to 0·94). INTERPRETATION: In line with previously published data, incidences of all-cause mortality and AESIs were similar in patients given belimumab and placebo, except for serious infusion or hypersensitivity reactions, serious depression, treatment-emergent suicidality, and sponsor-adjudicated serious suicide or self-injury events. FUNDING: GSK.

A longitudinal and transancestral analysis of DNA methylation patterns and disease activity in lupus patients.

Epigenetic dysregulation is implicated in the pathogenesis of lupus. We performed a longitudinal analysis to assess changes in DNA methylation in lupus neutrophils over 4 years of follow-up and across disease activity levels using 229 patient samples. We demonstrate that DNA methylation profiles in lupus are partly determined by ancestry-associated genetic variations and are highly stable over time. DNA methylation levels in 2 CpG sites correlated significantly with changes in lupus disease activity. Progressive demethylation in SNX18 was observed with increasing disease activity in African American patients. Importantly, demethylation of a CpG site located within GALNT18 was associated with the development of active lupus nephritis. Differentially methylated genes between African American and European American lupus patients include type I IFN-response genes such as IRF7 and IFI44, and genes related to the NF-κB pathway. TREML4, which plays a vital role in TLR signaling, was hypomethylated in African American patients and demonstrated a strong cis-methylation quantitative trait loci (cis-meQTL) effect among 8855 cis-meQTL associations identified in our study.

Patterns of Arterial Disease in Takayasu Arteritis and Giant Cell Arteritis.

OBJECTIVE: To identify and validate, using computer-driven methods, patterns of arterial disease in Takayasu arteritis (TAK) and giant cell arteritis (GCA). METHODS: Patients with TAK or GCA were studied from the Diagnostic and Classification Criteria for Vasculitis (DCVAS) cohort and a combined North American cohort. Case inclusion required evidence of large-vessel involvement, defined as stenosis, occlusion, or aneurysm by angiography/ultrasonography, or increased 18 F-fluorodeoxyglucose (FDG) uptake by positron emission tomography (PET) in at least 1 of 11 specified arterial territories. K-means cluster analysis identified groups of patients based on the pattern of arterial involvement. Cluster groups were identified in the DCVAS cohort and independently validated in the North American cohort. RESULTS: A total of 1,068 patients were included (DCVAS cohort: TAK = 461, GCA = 217; North American cohort: TAK = 225, GCA = 165). Six distinct clusters of patients were identified in DCVAS and validated in the North American cohort. Patients with TAK were more likely to have disease in the abdominal vasculature, bilateral disease of the subclavian and carotid arteries, or focal disease limited to the left subclavian artery than GCA (P < 0.01). Patients with GCA were more likely to have diffuse disease, involvement of bilateral axillary/subclavian arteries, or minimal disease without a definable pattern than TAK (P < 0.01). Patients with TAK were more likely to have damage by angiography, and patients with GCA were more likely to have arterial FDG uptake by PET without associated vascular damage. CONCLUSION: Arterial patterns of disease highlight both shared and divergent vascular patterns between TAK and GCA and should be incorporated into classification criteria for large-vessel vasculitis.

Derivation of an angiographically based classification system in Takayasu's arteritis: an observational study from India and North America.

OBJECTIVES: To develop and replicate, using data-driven methods, a novel classification system in Takayasu's arteritis based on distribution of arterial lesions. METHODS: Patients were included from four international cohorts at major academic centres: India (Christian Medical College Vellore); North America (National Institutes of Health, Vasculitis Clinical Research Consortium and Cleveland Clinic Foundation). All patients underwent whole-body angiography of the aorta and branch vessels, with categorization of arterial damage (stenosis, occlusion or aneurysm) in 13 territories. K-means cluster analysis was performed to identify subgroups of patients based on pattern of angiographic involvement. Cluster groups were identified in the Indian cohort and independently replicated in the North American cohorts. RESULTS: A total of 806 patients with Takayasu's arteritis from India (n = 581) and North America (n = 225) were included. Three distinct clusters defined by arterial damage were identified in the Indian cohort and replicated in each of the North American cohorts. Patients in cluster one had significantly more disease in the abdominal aorta, renal and mesenteric arteries (P < 0.01). Patients in cluster two had significantly more bilateral disease in the carotid and subclavian arteries (P < 0.01). Compared with clusters one and two, patients in cluster three had asymmetric disease with fewer involved territories (P < 0.01). Demographics, clinical symptoms and clinical outcomes differed by cluster. CONCLUSION: This large study in Takayasu's arteritis identified and replicated three novel subsets of patients based on patterns of arterial damage. Angiographic-based disease classification requires validation by demonstrating potential aetiological or prognostic implications.

Role of Macrophage Migration Inhibitory Factor in Granulomatosis With Polyangiitis.

OBJECTIVE: To examine the association between macrophage migration inhibitory factor (MIF) promoter polymorphisms and granulomatosis with polyangiitis (GPA) in human subjects, and to assess the role of MIF in a murine model of granulomatous vasculitis. METHODS: The human study involved 1,077 patients with GPA and healthy controls whose serum was genotyped by capillary electrophoresis for the MIF -794 CATT5-8 promoter microsatellite (rs5844572). MIF promoter, CATT-length-dependent gene expression in response to ß-glucan was assessed by gene reporter assays. In mouse studies, granulomatous disease was induced by injection of Candida albicans ß-glucan into wild-type (WT) or Mif-knockout (Mif-KO) C57BL/6 mice and C57BL/6 mice transgenically overexpressing Mif in lung epithelium (Mif lung-Tg2.1). Mice were treated with a neutralizing anti-MIF antibody and analyzed for the density of pulmonary granulomas, expression of inflammatory chemokines, and frequency of mortality. RESULTS: The percentage of human subjects carrying >5 CATT repeats in each MIF allele (high genotypic MIF expressers) was 60.2% among patients with GPA and 53.9% among healthy controls (adjusted P = 0.049). In response to granulomatous stimulation, human MIF gene expression increased proportionally with CATT length. Mif lung-Tg2.1 mice exhibited more pulmonary granulomas than WT mice, which in turn showed more granulomas than Mif-KO mice. A significantly higher percentage of Mif lung-Tg2.1 mice, compared to Mif-KO or WT mice, died when injected with Candida albicans ß-glucan, and treatment of these mice with an anti-MIF monoclonal antibody protected against a lethal outcome. Levels of MIF-dependent neutrophil/macrophage chemokines were elevated in the bronchoalveolar lavage fluid or plasma of Mif lung-Tg2.1 mice. CONCLUSION: Patients with GPA have an increased frequency of high MIF expression CATT alleles. Higher Mif expression increases the incidence of mortality and pulmonary granulomas in Mif lung-Tg2.1 mice, while anti-MIF treatment protects these mice against death. Blockade of MIF in high genotypic MIF expressers may therefore offer a selective pharmacologic therapy for GPA.

Brief Report: Whole-Exome Sequencing to Identify Rare Variants and Gene Networks That Increase Susceptibility to Scleroderma in African Americans.

OBJECTIVE: Whole-exome sequencing (WES) studies in systemic sclerosis (SSc) patients of European American (EA) ancestry have identified variants in the ATP8B4 gene and enrichment of variants in genes in the extracellular matrix (ECM)-related pathway that increase SSc susceptibility. This study was undertaken to evaluate the association of the ATP8B4 gene and the ECM-related pathway with SSc in a cohort of African American (AA) patients. METHODS: SSc patients of AA ancestry were enrolled from 23 academic centers across the US under the Genome Research in African American Scleroderma Patients consortium. Unrelated AA individuals without serologic evidence of autoimmunity who were enrolled in the Howard University Family Study were used as unaffected controls. Functional variants in genes reported in the 2 WES studies in EA patients with SSc were selected for gene association testing using the optimized sequence kernel association test (SKAT-O) and pathway analysis by Ingenuity Pathway Analysis in 379 patients and 411 controls. RESULTS: Principal components analysis demonstrated that the patients and controls had similar ancestral backgrounds, with roughly equal proportions of mean European admixture. Using SKAT-O, we examined the association of individual genes that were previously reported in EA patients and none remained significant, including ATP8B4 (P = 0.98). However, we confirmed the previously reported association of the ECM-related pathway with enrichment of variants within the COL13A1, COL18A1, COL22A1, COL4A3, COL4A4, COL5A2, PROK1, and SERPINE1 genes (corrected P = 1.95 × 10-4 ). CONCLUSION: In the largest genetic study in AA patients with SSc to date, our findings corroborate the role of functional variants that aggregate in a fibrotic pathway and increase SSc susceptibility.

CD4+CD28+KIR+CD11ahi T cells correlate with disease activity and are characterized by a pro-inflammatory epigenetic and transcriptional profile in lupus patients.

OBJECTIVE: The goal of this study was to comprehensively characterize CD4+CD28+ T cells overexpressing CD11a and KIR genes, and examine the relationship between this T cell subset, genetic risk, and disease activity in lupus. METHODS: The size of the CD4+CD28+KIR+CD11ahi T cell subset was determined by flow cytometry, and total genetic risk for lupus was calculated in 105 female patients using 43 confirmed genetic susceptibility loci. Primary CD4+CD28+KIR+CD11ahi T cells were isolated from lupus patients or were induced from healthy individuals using 5-azacytidine. Genome-wide DNA methylation was analyzed using an array-based approach, and the transcriptome was assessed by RNA sequencing. Transcripts in the CDR3 region were used to assess the TCR repertoire. Chromatin accessibility was determined using ATAC-seq. RESULTS: A total of 31,019 differentially methylated sites were identified in induced KIR+CD11ahi T cells with >99% being hypomethylated. RNA sequencing revealed a clear pro-inflammatory transcriptional profile. TCR repertoire analysis suggests less clonotype diversity in KIR+CD11ahi compared to autologous KIR-CD11alow T cells. Similarly, primary KIR+CD11ahi T cells isolated from lupus patients were hypomethylated and characterized by a pro-inflammatory chromatin structure. We show that the genetic risk for lupus was significantly higher in African-American compared to European-American lupus patients. The demethylated CD4+CD28+KIR+CD11ahi T cell subset size was a better predictor of disease activity in young (age ≤ 40) European-American patients independent of genetic risk. CONCLUSION: CD4+CD28+KIR+CD11ahi T cells are demethylated and characterized by pro-inflammatory epigenetic and transcriptional profiles in lupus. Eliminating these cells or blocking their pro-inflammatory characteristics might present a novel therapeutic approach for lupus.

Age-associated DNA methylation changes in naive CD4+ T cells suggest an evolving autoimmune epigenotype in aging T cells.

AIM: We sought to define age-associated DNA methylation changes in naive CD4+ T cells. MATERIALS & METHODS: Naive CD4+ T cells were collected from 74 healthy individuals (age 19-66 years), and age-related DNA methylation changes were characterized. RESULTS: We identified 11,431 age-associated CpG sites, 57% of which were hypermethylated with age. Hypermethylated sites were enriched in CpG islands and repressive transcription factor binding sites, while hypomethylated sites showed T cell specific enrichment in active enhancers marked by H3K27ac and H3K4me1. Our data emphasize cancer-related DNA methylation changes with age, and also reveal age-associated hypomethylation in immune-related pathways, such as T cell receptor signaling, FCγR-mediated phagocytosis, apoptosis and the mammalian target of rapamycin signaling pathway. The MAPK signaling pathway was hypermethylated with age, consistent with a defective MAPK signaling in aging T cells. CONCLUSION: Age-associated DNA methylation changes may alter regulatory mechanisms and signaling pathways that predispose to autoimmunity.

Epigenetic Reprogramming in Naive CD4+ T Cells Favoring T Cell Activation and Non-Th1 Effector T Cell Immune Response as an Early Event in Lupus Flares.

OBJECTIVE: Systemic lupus erythematosus (SLE) is a relapsing autoimmune disease that affects multiple organ systems. T cells play an important role in the pathogenesis of lupus; however, early T cell events triggering disease flares are incompletely understood. This study was undertaken to examine DNA methylation in naive CD4+ T cells from lupus patients to determine if epigenetic remodeling in CD4+ T cells is an early event in lupus flares. METHODS: A total of 74 lupus patients with an SLE Disease Activity Index score of 0-18 were included. Naive CD4+ T cells were isolated from peripheral blood samples, and DNA was extracted for genome-wide methylation assessment. RNA was also extracted from a subset of patients to determine the relationship between epigenetic changes and transcription activity using RNA sequencing and microRNA arrays. RESULTS: We demonstrated that naive CD4+ T cells in lupus undergo an epigenetic proinflammatory shift, implicating effector T cell responses in lupus flare. This epigenetic landscape change occurs without changes in expression of the corresponding genes, poises naive CD4+ T cells for Th2, Th17, and follicular helper T cell immune responses, and opposes inhibitory transforming growth factor ß signaling. Bioinformatics analyses indicate that the epigenetic modulator EZH2 might play an important role in shifting the epigenetic landscape, with increased disease activity in lupus naive CD4+ T cells. Further, the expression of microRNA-26a, which is sensitive to glucose availability and targets EZH2, was negatively correlated with disease activity in lupus patients. CONCLUSION: An epigenetic landscape shift in naive CD4+ T cells that favors T cell activation and non-Th1 immune responses predates transcription activity and correlates with lupus activity. A role for EZH2 dysregulation in triggering lupus flares warrants further investigation.

Autoimmune disease and vaccination: impact on infectious disease prevention and a look at future applications.

Vaccines hold promise both for the prevention of infections and as potential immunologic therapy for patients with autoimmune disease (AD). These patients are at high risk for both common and opportunistic infections, but this risk can be significantly reduced and even obviated with the use of recommended available vaccines. Unfortunately, patients with ADs are not routinely offered or provided indicated vaccinations and have higher rates of complications from vaccine-preventable illnesses than patients without ADs. In addition, vaccine therapy is currently under study for the treatment of autoimmune disorders, with early studies demonstrating immunomodulatory effects that may counter undesired immune activation and alleviate disease activity.

Ethnicity-specific epigenetic variation in naïve CD4+ T cells and the susceptibility to autoimmunity.

BACKGROUND: Genetic and epigenetic variability contributes to the susceptibility and pathogenesis of autoimmune diseases. T cells play an important role in several autoimmune conditions, including lupus, which is more common and more severe in people of African descent. To investigate inherent epigenetic differences in T cells between ethnicities, we characterized genome-wide DNA methylation patterns in naïve CD4+ T cells in healthy African-Americans and European-Americans, and then confirmed our findings in lupus patients. RESULTS: Impressive ethnicity-specific clustering of DNA methylation profiling in naïve CD4+ T cells was revealed. Hypomethylated loci in healthy African-Americans were significantly enriched in pro-apoptotic and pro-inflammatory genes. We also found hypomethylated genes in African-Americans to be disproportionately related to autoimmune diseases including lupus. We then confirmed that these genes, such as IL32, CD226, CDKN1A, and PTPRN2 were similarly hypomethylated in lupus patients of African-American compared to European-American descent. Using patch DNA methylation and luciferase reporter constructs, we showed that methylation of the IL32 promoter region reduces gene expression in vitro. Importantly, bisulfite DNA sequencing demonstrated that cis-acting genetic variants within and directly disrupting CpG sites account for some ethnicity-specific variability in DNA methylation. CONCLUSION: Ethnicity-specific inherited epigenetic susceptibility loci in CD4+ T cells provide clues to explain differences in the susceptibility to autoimmunity and possibly other T cell-related diseases between populations.

DNA methylation patterns in naïve CD4+ T cells identify epigenetic susceptibility loci for malar rash and discoid rash in systemic lupus erythematosus.

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.

Renal involvement in lupus is characterized by unique DNA methylation changes in naïve CD4+ T cells.

Systemic lupus erythematosus is a multi-system disease characterized by wide-spread DNA methylation changes. To identify epigenetic susceptibility loci for lupus nephritis, genome-wide DNA methylation changes in naïve CD4+ T cells were compared between two sets of lupus patients with and without a history of renal involvement. A total of 56 lupus patients (28 with renal involvement and 28 without renal involvement), and 56 age-, sex-, and ethnicity-matched healthy controls were included in our study. We identified 191 CG sites and 121 genes that were only differentially methylated in lupus patients with but not without a history of renal involvement. The tyrosine kinase gene TNK2 involved in cell trafficking and tissue invasion, and the phosphatase gene DUSP5 which dephosphorylates and inhibits the ERK signaling pathway, were among the most hypomethylated. Independent of disease activity, renal involvement is characterized by more robust demethylation in interferon regulated genes differentially methylated in both sets of lupus patients with and without renal involvement (fold change 1.4, P = 0.0014). The type-I interferon master regulator gene IRF7 is only hypomethylated in lupus patients with renal involvement. IRF-7 is an upstream transcription factor that regulates several loci demethylated only with renal involvement such as CD80, HERC5, IFI44, IRF7, ISG15, ISG20, ITGAX, and PARP12 (P = 1.78 × 10(-6)). Among the CG sites only hypomethylated with renal involvement, CG10152449 in CHST12 has a sensitivity of 85.7% and a specificity of 64.3% for stratifying lupus patients for a history of renal involvement (P = 0.0029). Our data identified novel epigenetic susceptibility loci that are differentially methylated with renal involvement in lupus. These loci will help better understand lupus nephritis, and provide a proof of principle for the potential applicability of specific methylation changes as predictors for specific organ involvement in lupus.

Disease Relapses among Patients with Giant Cell Arteritis: A Prospective, Longitudinal Cohort Study.

OBJECTIVE: To evaluate the frequency, timing, and clinical features of relapses in giant cell arteritis (GCA). METHODS: Patients with GCA enrolled in a prospective, multicenter, longitudinal study were included in the analysis. Relapse was defined as either new disease activity after a period of remission or worsening disease activity. RESULTS: The study included 128 subjects: 102 women (80%) and 26 men (20%). Mean ± SD age at diagnosis of GCA was 69.9 ± 8.6 years. Mean followup for the cohort was 21.4 ± 13.9 months. Median (interquartile range) duration of disease at study enrollment was 4.6 months (1.2, 16.8). During followup, 59 relapses were observed in 44 patients (34%). Ten patients (8%) experienced 2 or more relapses. The most common symptoms at relapse were headache (42%) and polymyalgia rheumatica (51%), but ischemic (some transient) manifestations (visual symptoms, tongue or jaw claudication, and/or limb claudication) occurred in 29% of relapses (12% cohort). Forty-three relapses (73%) occurred while patients were taking glucocorticoid therapy at a median (range) prednisone dose of 7.5 (0-35) mg. In 21% of relapses, both erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) were normal. Among 69 patients enrolled in the cohort with newly diagnosed disease, 24% experienced a first relapse within 12 months after diagnosis. CONCLUSION: Among patients with GCA, relapses are common, often occurring during treatment. ESR and CRP are frequently normal at times of clinical relapse, highlighting the need for better biomarkers to assess disease activity in GCA. There remains a need for effective therapeutic alternatives to glucocorticoids in GCA.

Identification of Susceptibility Loci in IL6, RPS9/LILRB3, and an Intergenic Locus on Chromosome 21q22 in Takayasu Arteritis in a Genome-Wide Association Study.

OBJECTIVE: Takayasu arteritis is a rare large vessel vasculitis with incompletely understood etiology. This study was undertaken to perform the first unbiased genome-wide association analysis of Takayasu arteritis. METHODS: Two independent cohorts of patients with Takayasu arteritis from Turkey and North America were included in our study. The Turkish cohort consisted of 559 patients and 489 controls, and the North American cohort consisted of 134 patients and 1,047 controls of European ancestry. Genotyping was performed using the Omni1-Quad and Omni2.5 genotyping arrays. Genotyping data were subjected to rigorous quality control measures and subsequently analyzed to discover genetic susceptibility loci for Takayasu arteritis. RESULTS: We identified genetic susceptibility loci for Takayasu arteritis with a genome-wide level of significance in IL6 (rs2069837) (odds ratio [OR] 2.07, P = 6.70 × 10(-9)), RPS9/LILRB3 (rs11666543) (OR 1.65, P = 2.34 × 10(-8)), and an intergenic locus on chromosome 21q22 (rs2836878) (OR 1.79, P = 3.62 × 10(-10)). The genetic susceptibility locus in RPS9/LILRB3 lies within the leukocyte receptor complex gene cluster on chromosome 19q13.4, and the disease risk variant in this locus correlates with reduced expression of multiple genes including the inhibitory leukocyte immunoglobulin-like receptor gene LILRB3 (P = 2.29 × 10(-8)). In addition, we identified candidate susceptibility genes with suggestive levels of association (P < 1 × 10(-5)) with Takayasu arteritis, including PCSK5, LILRA3, PPM1G/NRBP1, and PTK2B. CONCLUSION: Our findings indicate novel genetic susceptibility loci for Takayasu arteritis and uncover potentially important aspects of the pathophysiology of this form of vasculitis.