Established Systemic Lupus Erythematosus Research Articles

Retrospective cohort study identifying pulmonary complications in a cohort of patients with systemic lupus erythematosus.

Systemic lupus erythematosus (SLE) is a systemic autoimmune disease with multi organ involvement. One of the most common manifestations is pulmonary disease with a reported prevalence between 5%-90%. Given this wide range of prevalence, there is a need to more closely define types of pulmonary disease in SLE and associated risk factors. We sought to characterize the presentation of pulmonary manifestations in an established SLE cohort using electronic health record data. All patients were >18 years of age and had confirmed SLE by a rheumatologist using SLICC or 2019 ACR/EULAR classification criteria. 220 patients with imaging were included in this study; average age was 42.5 years, 86.7% identified as female, 60.5% identified as white, 37.3% as Black, and 1.82% as Asian. Generalized estimating equations were utilized to analyze the data, accounting for its repeated measured nature. We found an association between smoking (present/prior smoker) and radiologist reported disease on computerized tomography (CT) scan, as well as an association between smoking (present/prior smoker), older age, and male sex with having pulmonary disease identified on chest X-ray. The most common findings on CT and X-ray were increased lung density (24%, 12%) and atelectasis (18%, 10%). The most common disease found on CT was pleural effusion (24%) and mediastinal/axillary lymphadenopathy (16%). While our study is limited by the retrospective nature, our results show that certain factors, namely smoking, older age, or male sex should prompt clinicians to have a higher suspicion for lung disease in SLE patients.

Comparison of Attainment and Protective Effects of Lupus Low Disease Activity State in Patients With Newly Diagnosed Versus Established Systemic Lupus Erythematosus.

To assess whether Lupus Low Disease Activity State (LLDAS) attainment is associated with favorable outcomes in patients with recent onset systemic lupus erythematosus (SLE). Data from a 13-country longitudinal SLE cohort were collected prospectively between 2013 and 2020. An inception cohort was defined based on disease duration < 1 year at enrollment. Patient characteristics between inception and noninception cohorts were compared. Survival analyses were performed to examine the association between LLDAS attainment and damage accrual and flare. Of the total 4106 patients, 680 (16.6%) were recruited within 1 year of SLE diagnosis (inception cohort). Compared to the noninception cohort, inception cohort patients were significantly younger, had higher disease activity, and used more glucocorticoids, but had less organ damage at enrollment. Significantly fewer inception cohort patients were in LLDAS at enrollment than the noninception cohort (29.6% vs 52.3%, P < 0.001), but three-quarters of both groups achieved LLDAS at least once during follow-up. Limiting analysis only to patients not in LLDAS at enrollment, inception cohort patients were 60% more likely to attain LLDAS (hazard ratio 1.37, 95% CI 1.16-1.61, P < 0.001) than noninception cohort patients and attained LLDAS significantly faster. LLDAS attainment was significantly protective against flare in both the inception and noninception cohorts. A total of 88 (13.6%) inception cohort patients accrued organ damage during a median 2.2 years of follow-up. LLDAS attainment is protective from flare in recent onset SLE. Significant protection from damage accrual was not observed because of low rates of damage accrual in the first years after SLE diagnosis. (ClinicalTrials.gov: NCT03138941).

Performance of a New Instrument for the Measurement of Systemic Lupus Erythematosus Disease Activity: The SLE-DAS.

Systemic lupus erythematosus (SLE) is a chronic systemic autoimmune disease that affects multiple organ systems and manifests in a relapsing-remitting pattern. Consequently, it is paramount for rheumatologists to assess disease activity, identify flare-ups, and establish treatment goals for patients with SLE. In 2019, the Systemic Lupus Erythematosus Disease Activity Score (SLE-DAS) was introduced as a novel tool for measuring disease activity. This tool refines the parameters of the established SLE Disease Activity Index 2000 (SLEDAI-2K) to enhance the assessment process. This review aims to provide an introduction to the Systemic Lupus Erythematosus Disease Activity Score (SLE-DAS) and summarizes research on its development, its comparison with existing disease activity measures, and its performance in clinical settings. Literature searches on PubMed using the keyword "SLE-DAS" were conducted, covering publications from March 2019 to September 2023. Studies that compared SLE-DAS with other SLE disease activity measurement tools were reviewed. Findings indicated that SLE-DAS consistently performs on par with, and sometimes better than, traditional measures in assessing clinically meaningful changes, patient improvement, disease activity, health-related quality of life, hospitalization rates, and disease flare-ups. The association between SLE-DAS and mortality rates among patients with SLE, however, remains to be further explored. Although SLE-DAS is a promising and potentially effective tool for measuring SLE disease activity, additional research is needed to confirm its effectiveness and broaden its clinical use.

Genome-wide DNA methylation analysis implicates enrichment of interferon pathway in African American patients with Systemic Lupus Erythematosus and European Americans with lupus nephritis

Systemic Lupus Erythematosus (SLE) is a chronic, multisystem, inflammatory autoimmune disease that disproportionately affects women. Trends in SLE prevalence and clinical course differ by ancestry, with those of African American ancestry presenting with more active, severe and rapidly progressive disease than European Americans. Previous research established altered epigenetic signatures in SLE patients compared to controls. However, the contribution of aberrant DNA methylation (DNAm) to the risk of SLE by ancestry and differences among patients with SLE-associated Lupus Nephritis (LN) has not been well described. We evaluated the DNA methylomes of 87 individuals including 41 SLE patients, with and without LN, and 46 controls enrolled in an ancestry diverse, well-characterized cohort study of established SLE (41 SLE patients [20 SLE-LN+, 21 SLE-LN-] and 46 sex-, race- and age-matched controls; 55% African American, 45% European American). Participants were genotyped using the Infinium Global Diversity Array (GDA), and genetic ancestry was estimated using principal components. Genome-wide DNA methylation was initially measured using the Illumina MethylationEPIC 850K Beadchip array followed by methylation-specific qPCR to validate the methylation status at putative loci. Differentially Methylated Positions (DMP) were identified using a case-control approach adjusted for ancestry. We identified a total of 51 DMPs in CpGs among SLE patients compared to controls. Genes proximal to these CpGs were highly enriched for involvement in type I interferon signaling. DMPs among European American SLE patients with LN were similar to African American SLE patients with and without LN. Our findings were validated using an orthogonal, methyl-specific PCR for three SLE-associated DMPs near or proximal to MX1, USP18, and IFITM1. Our study confirms previous reports that DMPs in CpGs associated with SLE are enriched in type I interferon genes. However, we show that European American SLE patients with LN have similar DNAm patterns to African American SLE patients irrespective of LN, suggesting that aberrant DNAm alters activity of type I interferon pathway leading to more severe disease independent of ancestry.

Phenotype Risk Score but Not Genetic Risk Score Aids in Identifying Individuals With Systemic Lupus Erythematosus in the Electronic Health Record.

Systemic lupus erythematosus (SLE) poses diagnostic challenges. We undertook this study to evaluate the utility of a phenotype risk score (PheRS) and a genetic risk score (GRS) to identify SLE individuals in a real-world setting. Using a de-identified electronic health record (EHR) database with an associated DNA biobank, we identified 789 SLE cases and 2,261 controls with available MEGAEX genotyping. A PheRS for SLE was developed using billing codes that captured American College of Rheumatology SLE criteria. We developed a GRS with 58 SLE risk single-nucleotide polymorphisms (SNPs). SLE cases had a significantly higher PheRS (mean ± SD 7.7 ± 8.0 versus 0.8 ± 2.0 in controls; P < 0.001) and GRS (mean ± SD 12.2 ± 2.3 versus 11.0 ± 2.0 in controls; P < 0.001). Black individuals with SLE had a higher PheRS compared to White individuals (mean ± SD 10.0 ± 10.1 versus 7.1 ± 7.2, respectively; P = 0.002) but a lower GRS (mean ± SD 9.0 ± 1.4 versus 12.3 ± 1.7, respectively; P < 0.001). Models predicting SLE that used only the PheRS had an area under the curve (AUC) of 0.87. Adding the GRS to the PheRS resulted in a minimal difference with an AUC of 0.89. On chart review, controls with the highest PheRS and GRS had undiagnosed SLE. We developed a SLE PheRS to identify established and undiagnosed SLE individuals. A SLE GRS using known risk SNPs did not add value beyond the PheRS and was of limited utility in Black individuals with SLE. More work is needed to understand the genetic risks of SLE in diverse populations.

Limited Association between Antibodies to Oxidized Low-Density Lipoprotein and Vascular Affection in Patients with Established Systemic Lupus Erythematosus.

Patients with systemic lupus erythematosus (SLE) are at an increased risk of cardiovascular disease. We aimed to evaluate whether antibodies to oxidized low-density lipoprotein (anti-oxLDL) were associated with subclinical atherosclerosis in patients with different SLE phenotypes (lupus nephritis, antiphospholipid syndrome, and skin and joint involvement). Anti-oxLDL was measured by enzyme-linked immunosorbent assay in 60 patients with SLE, 60 healthy controls (HCs) and 30 subjects with anti-neutrophil cytoplasmic antibody-associated vasculitis (AAV). Intima-media thickness (IMT) assessment of vessel walls and plaque occurrence were recorded using high-frequency ultrasound. In the SLE cohort, anti-oxLDL was again assessed in 57 of the 60 individuals approximately 3 years later. The levels of anti-oxLDL in the SLE group (median 5829 U/mL) were not significantly different from those in the HCs group (median 4568 U/mL), while patients with AAV showed significantly higher levels (median 7817 U/mL). The levels did not differ between the SLE subgroups. A significant correlation was found with IMT in the common femoral artery in the SLE cohort, but no association with plaque occurrence was observed. The levels of anti-oxLDL antibodies in the SLE group were significantly higher at inclusion compared to 3 years later (median 5707 versus 1503 U/mL, p < 0.0001). Overall, we found no convincing support for strong associations between vascular affection and anti-oxLDL antibodies in SLE.

308 Machine learning to predict genetic variation and cardiovascular risk in Hispanic patients with Systemic lupus erythematosus

OBJECTIVES/GOALS: Cardiovascular disease (CVD) is the most common cause of death in systemic lupus erythematosus (SLE). Genome-wide association studies have identified single nucleotide polymorphisms linked with CVD risk, but the association with SLE is not well established. We aimed to determine associations using machine learning in a multi-ethnic lupus cohort. METHODS/STUDY POPULATION: We will use data from the established SLE cohort study named Genetic Profile Predicting the Phenotype (PROFILE). PROFILE was constituted in 1998 by combining existing cohorts at multiple sites which are also of defined ethnicity (Hispanics of Mexican ancestry and Puerto Rico, African American, and Caucasian). The cohort consists of 3,118 individuals and the database contains socioeconomic–demographic, clinical, laboratory, and genetic variables. Genetic data consist of 196,524 single nucleotide polymorphisms. To detect risk genes and predict an individual’s SLE risk will design a random forest classifier using SNP genotype data. Logistic regression models will be performed with CVD as the outcome, adjusted for age, sex, ethnicity, disease duration, and traditional and nontraditional risk factors for CVD. RESULTS/ANTICIPATED RESULTS: We expect to find several established and new susceptibility genes associated with CVD. DISCUSSION/SIGNIFICANCE: This approach offers an opportunity to characterize distinct genetic risk factors and the relationship of CVD with SLE. These data may be important in the identification of patients at high risk for such events and may allow the design of preventive strategies which may beneficially have an impact on the morbidity and mortality of SLE patients.

Emerging concepts of type I interferons in SLE pathogenesis and therapy.

Type I interferons have been suspected for decades to have a crucial role in the pathogenesis of systemic lupus erythematosus (SLE). Evidence has now overturned several long-held assumptions about how type I interferons are regulated and cause pathological conditions, providing a new view of SLE pathogenesis that resolves longstanding clinical dilemmas. This evidence includes data on interferons in relation to genetic predisposition and epigenetic regulation. Importantly, data are now available on the role of interferons in the early phases of the disease and the importance of non-haematopoietic cellular sources of type I interferons, such as keratinocytes, renal tubular cells, glial cells and synovial stromal cells, as well as local responses to type I interferons within these tissues. These local effects are found not only in inflamed target organs in established SLE, but also in histologically normal skin during asymptomatic preclinical phases, suggesting a role in disease initiation. In terms of clinical application, evidence relating to biomarkers to characterize the type I interferon system is complex, and, notably, interferon-blocking therapies are now licensed for the treatment of SLE. Collectively, the available data enable us to propose a model of disease pathogenesis that invokes the unique value of interferon-targeted therapies. Accordingly, future approaches in SLE involving disease reclassification and preventative strategies in preclinical phases should be investigated.

Increased IL-23R+ Th Cells Population Exhibits Higher SLEDAI-2K Scores in Systemic Lupus Erythematosus Patients.

The IL-23/IL-17 axis plays causative roles in the development and progression of systemic lupus erythematosus (SLE). However, it remains unclear if the IL-17RA+ and IL-23R+ T helper (Th) cells populations are associated with the serum IL-17 and IL-23 levels, or with the immunological parameters and disease activities in SLE patients. Herein, we examined the proportion of IL-17RA+ and IL-23R+ Th cells and serum levels of IL-17 and IL-23 in established SLE patients (n = 50) compared with healthy controls (n = 50). The associations of these interleukins and their receptors with immunological parameters [anti-nuclear antibody (ANA), anti-dsDNA antibody, and C-reactive protein (CRP)] and SLE disease activity (SLEDAI-2K scores) in SLE patients were assessed. CD3+CD4+ Th cells of SLE patients demonstrated significantly elevated IL-17RA+ (p = 1.12 x 10-4) or IL-23R+ (p = 1.98 x 10-29) populations compared with the healthy controls. Serum IL-17 levels were significantly lower in SLE patients compared with the healthy controls (p = 8.32 x 10-5), while no significant difference was observed for the IL-23 serum levels between both groups. IL-23R+ Th cells population was significantly associated with higher SLEDAI-2K scores (p = 0.017). In multivariate analysis, the proportion of IL-23R+ Th cells remained significantly associated with higher SLEDAI-2K scores independent of prednisolone intake (p = 0.027). No associations were observed between the interleukin parameters (i.e., IL-17, IL-23, IL-17RA+ Th cells, and IL-23R+ Th cells) with ANA, anti-dsDNA, and CRP status, suggesting that the IL-17/IL-23 axis acts independently of these immunological parameters. In conclusion, our results support that therapeutic inhibition of the IL-23/IL-17 axis receptors on Th cells, particularly IL-23R, is potentially relevant in SLE patients.

Skin reaction to capsaicin in patients with systemic lupus erythematosus compared to healthy controls.

Background:The interaction between nervous and immune systems has been under investigation. Transient receptor potential vanilloid type 1(TRPV1) is a ligand gated calcium channel expressed by sensory neurons which mediates neurogenic inflammatory response. Substance p which can be released following exposure to capsaicin is a TRPV1 inducer, shown to have altered concentration and function in mice with systemic lupus erythematosus (SLE). We evaluated skin reaction to capsaicin in newly diagnosed and established SLE patients compared to healthy controls.Methods:Twenty-nine SLE patients (12 newly diagnosed cases under treatment, and 17 established ones, not receiving medications) who referred to rheumatologic disease research center, and 33 healthy subjects of the control group were recruited in this study. A topical solution of capsaicin (0.075%) was applied on the volar forearm during skin test, and time to the tingling sensation, area of induration and area of redness (centimeters2) were recorded after 5, 10, and 20 minutes.Results:The area of redness and area of induration within 15 minutes, time to the tingling sensation (P=0.02), and the overall frequency of tingling sensation (P=0.01) after capsaicin skin test was considerably higher in SLE patients than the healthy controls. Redness, induration and tingling sensation were more frequent but not statistically significant among the established SLE group compared to the newly diagnosed patients.Conclusion:Since skin reaction to capsaicin is more prominent in SLE patients than the healthy individuals, neurogenic inflammation and the role of P substance should be investigated more in ongoing lupus. Capsaicin test can not predict lupus activity.

Generation of Systemic Lupus Erythematosus Patient-Derived Induced Pluripotent Stem Cells from Blood.

Systemic lupus erythematosus (SLE) is a chronic inflammatory autoimmune disease characterized by the production of multiple autoimmune antibodies and potentially involves any organ or tissue with a broad range of clinical manifestations. Conventional therapy still utilizes glucocorticoids and immunosuppressants. However, some patients show inadequate responses to glucocorticoids and immunosuppression, which may induce secondary immune dysfunction and severe infection as well as lead to an increased tumor risk. The lack of in vitro models has hampered progress in understanding and treating SLE. Patient-derived induced pluripotent stem cells (iPSCs) may provide a unique opportunity for modeling in vitro diseases as well as a platform for drug screening in individual patients. We isolated peripheral blood mononuclear cells from blood to explore the establishment of an in vitro model platform for SLE and directly purified CD34+ cells and seeded them for expansion. CD34+ cells were forced to express seven pluripotency factors, OCT4, SOX2, NANOG, LIN28, c-MYC, KLF4, and SV40LT, through transduction in lentiviral vectors. The morphological characteristics of induced pluripotent stem-like cells, such as prominent nucleoli and a high nucleus-to-cytoplasm ratio, were observed. The pluripotency of established SLE patient-derived iPSCs was confirmed by the expression of embryonic stem cell (ESC) markers and the ability of cells to differentiate into multiple cell lines. SLE patient-derived iPSCs exhibited human ESC properties, including morphology; growth characteristics; expression of pluripotency, genes, and surface markers; and teratoma formation. In conclusion, we generated SLE patient-derived iPSCs and validated their pluripotency. This study is a first but critical step that can provide a model platform for research aimed at understanding the SLE mechanism, which may lead to the discovery of new targets or compounds for the treatment of this disease.

Bullous systemic lupus erythematosus as a presenting manifestation of systemic lupus erythematosus in a child

Introduction: Bullous systemic lupus erythematosus (BSLE) is a rare blistering disorder seen in the background of systemic lupus erythematosus (SLE). It can either be a presenting feature or manifest later in an established case of SLE often accompanied by lupus nephritis. Case Report: We report a case of a 12-year-old girl in whom the presenting feature of SLE was BSLE, along with hemolytic anemia. Discussion: Bullous SLE should be considered in the differential diagnosis in children presenting with vesiculobullous lesions even in the absence of established SLE

Identification of Lupus Podocytopathy with Coexistent Glomerular Diseases – A Case Report

Abstract Introduction/Objective Lupus podocytopathy (LP), featured by nephrotic syndrome, is a unique subtype of lupus nephritis that mimics minimal change disease or primary focal segmental glomerulosclerosis (FSGS) on renal biopsy with diffuse podocyte foot process effacement and no capillary-loop immune deposits. LP usually presents on a background of ISN/RPS class I or class II lupus nephritis, and very rarely may present without immune deposits. Diagnosis of LP, when confounded by other glomerular diseases associated with nephrotic syndrome, can be very challenging and requires thorough clinical and pathology correlations. Methods Here we report a case of LP in a patient with nephrotic syndrome and multiple comorbidities affecting kidneys. A 24-year-old female with type-I diabetes, psoriasis, and intermittent arthritis/rash of unknown etiology, presented with abrupt onset of nephrotic proteinuria attributed to recent low dose prednisone therapy, and renal insufficiency. A renal biopsy showed nodular glomerulosclerosis and FSGS. No immune deposits were identified by immunofluorescence or electron microscopy. Ultrastructurally there was also diffuse glomerular basement membrane thickening and over 90% podocyte foot process effacement. With no established systemic lupus erythematosus (SLE), the case was initially diagnosed as diabetic nephropathy with coexistent FSGS as the etiologies for nephrotic proteinuria, and the patient was put on ACEI and diuretics. However, massive proteinuria persisted, and the patient also developed pancytopenia. Serology concurrent with the biopsy came out later showing positive autoantibodies against dsDNA, Smith, and Histone. With continued worsening of creatinine, a renal biopsy was repeated revealing essentially similar findings to the first biopsy. Results Integrating the serology results and clinical presentation, SLE was favored. The pathology findings were re- evaluated and considered to be most consistent with LP and coexistent diabetic nephropathy, with FSGS either a component of LP or an independent lesion secondary to diabetes or hypertension. The patient was started with high dose prednisone at 60 mg/day. One month later, her proteinuria, serum creatinine, pancytopenia, skin rash, and arthritis were all significantly improved. Conclusion LP can be easily masked by coexistent glomerular diseases. Sufficient awareness of the entity is necessary for the appropriate diagnosis and treatment.

SLE Plasma Profiling Identifies Unique Signatures of Lupus Nephritis and Discoid Lupus

Systemic lupus erythematosus (SLE) impacts multiple organ systems, although the causes of many individual SLE pathologies are poorly understood. This study was designed to elucidate organ-specific inflammation by identifying proteins that correlate with SLE organ involvement and to evaluate established biomarkers of disease activity across a diverse patient cohort. Plasma proteins and autoantibodies were measured across seven SLE manifestations. Comparative analyses between pathologies and correlation with the SLE Disease Activity Index (SLEDAI) were used to identify proteins associated with organ-specific and composite disease activity. Established biomarkers of composite disease activity, SLE-associated antibodies, type I interferon (IFN), and complement C3, correlated with composite SLEDAI, but did not significantly associate with many individual SLE pathologies. Two clusters of proteins were associated with renal disease in lupus nephritis samples. One cluster included markers of infiltrating leukocytes and the second cluster included markers of tissue remodelling. In patients with discoid lupus, a distinct signature consisting of elevated immunoglobulin A autoantibodies and interleukin-23 was observed. Our findings indicate that proteins from blood samples can be used to identify protein signatures that are distinct from established SLE biomarkers and SLEDAI and could be used to conveniently monitor multiple inflammatory pathways present in different organ systems.

Determinants of health-related quality of life in systemic lupus erythematosus: amonocentric, retrospective long-term observational study in Germany

Improvement of health-related quality of life (HRQoL) is aprioritized treatment target in systemic lupus erythematosus (SLE). Aretrospective chart review of patients with repeated HRQoL measurements from the outpatient department was conducted in order to better understand which factors drive HRQoL in established SLE. Of particular interest was the association between HRQoL and disease activity. The medical outcomes study short form36 (SF-36), systemic lupus activity measure (SLAM) and routine clinical data of 169 patients (83% female, mean age 40.3 ± 13years, disease duration 9.4 ± 7years) over an average of 7.1 ± 4.2years were available for analysis by linear mixed modelling. Factors associated with the physical component summary (PCS) and mental component summary (MCS) of the SF-36 were assessed. The proportion of HRQoL which could be explained by the variables was estimated by marginal R2 (mR2) and conditional R2 (cR2). At baseline, SLE patients showed a reduced HRQoL in all subscales of the SF-36 including PCS and MCS with the exception of vitality. A higher PCS over time was significantly associated with concurrent parameters, such as intake of antimalarial drugs, no glucocorticoid use, less fatigue, lower disease activity as well as to the baseline parameters of younger age and higher PCS (mR2 54.7%, cR2 59.9%). A higher MCS was associated with concurrent use of glucocorticoids and a higher baseline MCS (mR2 21.7%, cR2 25.1%). The use of antimalarial drugs and no glucocorticoid intake as well as low current disease activity are modifiable factors associated with a better physical HRQoL. The mental component of HRQoL was poorly represented by conventional parameters and not associated with parameters of disease activity in the present study cohort.

Comprehensive Longitudinal Surveillance of the IgG Autoantibody Repertoire in Established Systemic Lupus Erythematosus.

To investigate the role of epitope spreading in established systemic lupus erythematosus (SLE). IgG autoantibody reactivity with 398 distinct recombinant proteins was measured over a period of 6 years in 69 SLE patients and compared to that in 45 controls. Changes in mean fluorescence intensity (MFI), number of autoantibodies to distinct antigens, and reactivity with distinct clones of established antigenic targets (e.g., U1 RNP, Sm, and ribosomal P) representing epitope fine mapping were assessed. Linear mixed modeling, adjusted with Bonferroni correction for age and sex, was applied. The total number of autoantibodies, mean MFI, and number of autoantibodies in epitope fine mapping were higher in SLE patients compared to controls (P < 0.0001). The total number of antibodies to distinct autoantigens remained stable over time, while the mean MFI decreased over time in SLE (P < 0.021). SLE patients showed variable recognition of epitopes in fine mapping over time. In particular, in SLE patients, more clones of the U1 RNP complex were recognized at the time of new organ involvement (+0.65) (P = 0.007). Mean MFI was higher in patients with lupus nephritis (P = 0.047). The time-averaged MFIs of 22 individual autoantibodies (including double-stranded DNA [dsDNA]) were higher, after Bonferroni correction, in SLE (P < 0.0001). The MFIs of dsDNA and histone cluster 2 H3c were associated with scores on the Systemic Lupus Activity Measure (P < 0.0001). Longitudinal surveillance of the IgG autoantibody repertoire in established SLE reveals evidence of sustained breadth of autoantibody repertoire without significant expansion. Associations of disease activity with dsDNA and with histone H3 autoantibodies were confirmed.

The study of interactions between genome and exposome in the development of systemic lupus erythematosus.

Systemic lupus erythematosus (SLE) is a systemic inflammatory autoimmune disease characterized by a broad spectrum of clinical and serological manifestations. This may reflect a complex and multifactorial etiology involving several identified genetic and environmental factors, though not explaining the full risk of SLE. Established SLE risk genotypes are either very rare or with modest effect sizes and twin studies indicate that other factors besides genetics must be operative in SLE etiology. The exposome comprises the cumulative environmental influences on an individual and associated biological responses through the lifespan. It has been demonstrated that exposure to silica, smoking and exogenous hormones candidate as environmental risk factors in SLE, while alcohol consumption seems to be protective. Very few studies have investigated potential gene-environment interactions to determine if some of the unexplained SLE risk is attributable hereto. Even less have focused on interactions between specific risk genotypes and environmental exposures relevant to SLE pathogenesis. Cohort and case-control studies may provide data to suggest such biological interactions and various statistical measures of interaction can indicate the magnitude of such. However, such studies do often have very large sample-size requirements and we suggest that the rarity of SLE to some extent can be compensated by increasing the ratio of controls. This review summarizes the current body of knowledge on gene-environment interactions in SLE. We argue for the prioritization of studies that comprise the increasing details available of the genome and exposome relevant to SLE as they have the potential to disclose new aspects of SLE pathogenesis including phenotype heterogeneity.

Bone turnover markers in relation to vitamin D status and disease activity in adults with systemic lupus erythematosus.

Patients with systemic lupus erythematosus (SLE) have altered bone metabolism and are at risk of osteoporosis. The aim of this study was to examine bone turnover markers in relation to vitamin D, disease activity, and clinical risk factors in patients with established SLE. Clinical registry and biorepository data of 42 SLE patients were assessed. Serum samples were analyzed for osteocalcin as a marker of bone formation, C-terminal telopeptide of type 1 collagen (CTX) as a marker for bone resorption, and 25-hydroxy vitamin D. Patients with a Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI) score of 3 or greater had a lower median osteocalcin level ( P = 0.02) and lower 25-hydroxy vitamin D levels ( P = 0.03) than those with a score of less than 3. No significant differences in bone turnover markers were observed between patients dichotomized into subgroups using a 25-hydroxy vitamin D cut-off of 30 ng/mL or by a daily prednisone dose greater than or 5 mg or less. Osteocalcin levels were negatively correlated with SLEDAI scores ( P = 0.034), and were positively correlated with the CTX index (a ratio of measured CTX value to the upper limit of the normal value for age and gender) ( P < 0.01). No association between the CTX index and SLEDAI scores was found. SLE disease activity may have direct effects on bone formation, but no effects on bone resorption in this cohort of established SLE patients, probably related to the inflammation-suppressing effects of glucocorticoids, thereby inhibiting cytokine-induced osteoclast activity. A fine balance exists between disease control and the use of glucocorticoids with regard to bone health.

Cluster analysis of autoimmune rheumatic diseases based on autoantibodies. New insights for polyautoimmunity

Autoimmune diseases (ADs) are a chronic and clinically heterogeneous group of diseases characterized by share common immunopathogenic mechanisms and risk factors (i.e., the autoimmune tautology), which explain the fact that one AD may coexist with others (i.e., polyautoimmunity - PolyA). In the present exploratory study, a mixed-cluster analysis of the most common autoimmune rheumatic diseases (ARDs) was done. A total of 187 consecutive women with established systemic lupus erythematosus (n = 70), rheumatoid arthritis (n = 51), systemic sclerosis (n = 35) and Sjögren's syndrome (n = 31) were included. A comprehensive clinical, autoantibody and cytokine assessment was simultaneously done. Total PolyA was registered in 142 (75.9%) patients. Six clusters were obtained, built mainly on autoantibodies: PolyA-I to -VI. The PolyA-III cluster showed the highest frequency of overt PolyA (p = 0.01), and the PolyA-I, -III, and -IV clusters exhibited the highest positivity for IL-12/23p40 (p = 0.015). These results provide new insights into the pathophysiology of PolyA and warrant prospective validation to enable development of a more accurate taxonomy of ARDs.

Multicenter Delphi Exercise to Identify Important Key Items for Classifying Systemic Lupus Erythematosus.

The American College of Rheumatology and the European League Against Rheumatism embarked on a project to reevaluate classification criteria for systemic lupus erythematosus (SLE). The first phase of the classification project involved generation of a broad set of items potentially useful for classification of SLE and their selection for use in a subsequent forced-choice decision analysis. A large international group of expert lupus clinicians was invited to participate in a 2-step process to generate, rate, and select items based on their importance in diagnosing early and established SLE, via a web-based survey. A total of 135 and 147 experts were invited to participate in the item-generation and item-reduction process, respectively. Of 145 items generated, item reduction resulted in 40 candidate items moving forward to the next phase. Key features for classifying both early and established SLE included characteristic autoantibodies, specific renal features, and skin manifestations. A small majority (51%) stated that 1 organ system would be sufficient for classifying SLE, but that additional typical laboratory features (antinuclear antibody, anti-double-stranded DNA) would be required. Notably, 85% of the expert group would positively classify SLE if renal pathology alone showed lupus nephritis. The Delphi exercise resulted in a set of 40 candidate criteria for the classification of SLE for subsequent assessment. This study comprised the largest panel ever involved in the development of SLE classification criteria, providing a broadly representative view of the current approach to classification of SLE.