What can epidemiology tell us about systemic lupus erythematosus?

Cutaneous Lupus Erythematosus: Review and Considerations for Older Populations

Though more common earlier in life, increasing attention is being focused on the development of cutaneous lupus erythematosus (CLE) in patients with advancing age. Studies show that CLE is more common in older populations than previously thought, and all CLE subtypes are possible in this group. Just like patients in the third or fourth decade of life, CLE may appear alongside or independent of systemic lupus erythematosus. Older populations manifesting CLE for the first time seem to have a lower risk of progression to systemic disease than younger peers, and are more commonly White. CLE must be carefully distinguished from other skin conditions that have a predilection for presentation in older populations, including rosacea, lichen planus, and other autoimmune conditions such as dermatomyositis or pemphigus/pemphigoid. It is thought that most CLE in older populations is drug-induced, with drug-induced subacute cutaneous lupus erythematosus being the most common subtype. Management of CLE in older patients focuses on eliminating unnecessary medications known to induce CLE, and otherwise treatment proceeds similarly to that in younger patients, with a few special considerations.

Increased risk of rheumatoid arthritis among patients with endometriosis: a nationwide population-based cohort study

OBJECTIVES

Autoimmunity may play a role in endometriosis. The association between endometriosis and RA remains unknown. This study was conducted to identify any evidence for this relationship.

METHODS

This 13-year, nationwide, population-based, retrospective cohort study analysed the risk of RA in a cohort of individuals with endometriosis. We investigated the incidence of RA among patients with endometriosis using data from the Longitudinal Health Insurance Database 2000, which is maintained by the Taiwan National Health Research Institutes. We used propensity scores to match comorbidities in the two cohorts. Kaplan-Meier analysis and Cox proportional hazard model were employed to analyse the association between endometriosis and RA among patients with different potential risks.

RESULTS

Patients with endometriosis [adjusted hazard ratio (HR) 1.75, 95% CI 1.27, 2.41], aged ≥45 years (adjusted HR 1.50, 95% CI 1.06-2.13) and with autoimmune disease (adjusted HR 6.99, 95% CI 2.84-17.21) had a significantly higher risk of RA. The analyses also showed that when stratified by age, comorbidities and medication use, the risk of RA in patients with endometriosis was also higher than in those without endometriosis.

CONCLUSIONS

This 14-year, nationwide, population-based retrospective cohort study revealed that patients with endometriosis have a higher risk of RA. In the clinical management of patients with RA, rheumatologists should be especially mindful of the possibility of underlying endometriosis.

Contribution of mouse models in our understanding of lupus

Laboratory animal models are beneficial when they recapitulate all or just some of the clinical and immunological manifestations of the disease. Various animals such as cats, rats, dogs, hamsters, guinea pigs, rabbits, horses, minks, pigs, and primates have been described lupus-like phenotype. However, a mouse has remained the preferable animal for scientific investigations as a result of their reduced lifespan, easy reproduction, markedly low costs, public acceptance, ease of genetic management, and the probability to stay under standardized conditions. It is highly challenging to establish a mouse model with all features of lupus because of the difficulty and the heterogeneity of the clinical features in systemic lupus erythematous (SLE). Additionally, due to the multiple differences between the mouse and human immune system, the direct translation usually fails. Each mouse model has specific characteristics and shares many subsets of aspects with the disease observed in humans, which gives researchers a tool to select their particular needs. Over 50 years, many mice models have been developed and used to dissect the pathogenesis of lupus, also to test novel drugs and therapies. In general, mice models that contribute considerably in SLE understanding can be divided into four groups: Spontaneous models, induced models, genetically modified models, along with humanizing mouse models that are the link between the mouse and human immune system. In this updated review, we will present what has been learned from different lupus mice models and how these models have contributed to a better understanding of lupus pathogenesis and treatment.

Influence of Alcohol Consumption on the Risk of Systemic Lupus Erythematosus Among Women in the Nurses' Health Study Cohorts

OBJECTIVE

Moderate alcohol consumption has antiinflammatory properties and is associated with reduced cardiovascular disease and rheumatoid arthritis risks. We investigated the association between alcohol consumption and systemic lupus erythematosus (SLE) risk among women followed in the Nurses' Health Study (NHS) cohorts.

METHODS

We conducted a prospective cohort analysis among 204,055 women in NHS (1980-2012) and NHSII (1989-2011) who were free of connective tissue disease and provided alcohol information at baseline. Alcohol consumption was assessed using a semiquantitative food frequency questionnaire every 2-4 years. We validated incident SLE through medical record review after self-report. Cox proportional hazards models estimated hazard ratios (HRs) for SLE based on cumulative average alcohol intake, adjusting for potential confounders. Results were meta-analyzed using DerSimonian and Laird random-effects models. We further investigated SLE risk associated with wine, beer, and liquor intake.

RESULTS

We identified 125 incident SLE cases in NHS and 119 in NHSII. Mean ± SD age at SLE diagnosis was 55.8 ± 9.5 years in NHS and 43.4 ± 7.7 years in NHSII. Compared to no alcohol intake, the meta-analyzed multivariable HR for cumulative alcohol consumption ≥5 gm/day was 0.61 (95% confidence interval [95% CI] 0.41-0.89). When limiting alcohol exposure to >4 years prior to SLE diagnosis, the multivariable HR was similar: 0.61 (95% CI 0.41-0.91). Women who drank ≥2 servings/week of wine had significantly decreased SLE risk (HR 0.65, 95% CI 0.45-0.96) compared to women who did not drink wine.

CONCLUSION

In these large prospective cohorts, we demonstrated an inverse association between moderate alcohol consumption (≥5 grams or 0.5 drink/day) and SLE risk in women.

Understanding the role of environmental factors in the development of systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a multisystem disease with a complex etiology. Its risk is higher among women, racial and ethnic minorities, and individuals with a family history of SLE or related autoimmune diseases. It is believed that genetic factors interact with environmental exposures throughout the lifespan to influence susceptibility to developing SLE. The strongest epidemiologic evidence exists for increased risk of SLE associated with exposure to crystalline silica, current cigarette smoking, use of oral contraceptives, and postmenopausal hormone replacement therapy, while there is an inverse association with alcohol use. Emerging research results suggest possible associations of SLE risk with exposure to solvents, residential and agricultural pesticides, heavy metals, and air pollution. Ultraviolet light, certain infections, and vaccinations have also been hypothesized to be related to SLE risk. Mechanisms linking environmental exposures and SLE include epigenetic modifications resulting from exposures, increased oxidative stress, systemic inflammation and inflammatory cytokine upregulation, and hormonal effects. Research needs to include new studies of environmental risk factors for SLE in general, with a focus on lifetime exposure assessment. In addition, studies in susceptible subgroups, such as family members, studies based on genetic risk profiles, and studies in individuals with evidence of pre-clinical autoimmunity based on the detection of specific auto-antibodies are also required. Understanding the role of environmental exposures in the development of SLE may help identify modifiable risk factors and potential etiological mechanisms.

Incidence and prevalence of systemic lupus erythematosus among the native Arab population in UAE

Background and objectives There is a paucity of information about the epidemiology of systemic lupus erythematosus (SLE) amongst Arabs. The objective of this study was to determine the incidence and prevalence of SLE among the native Arab population of United Arab Emirates (UAE). Methods Patients with SLE were identified from three sources: medical records of two local tertiary hospitals (four years; 2009 to 2012), laboratory requests for serum double stranded deoxyribonucleic acid and serum anti-nuclear antibody and confirmed histopathologic diagnosis of SLE (skin and kidney biopsy specimens). All the patients identified with SLE met the criteria of the American College of Rheumatology. Incidence and prevalence were calculated using the state records of the UAE native population as the denominator. The age-adjusted incidence was calculated by direct standardization using the World Health Organization world standard population 2000-2025. Results Sixteen new cases (13 females and three males) fulfilled the American College of Rheumatology SLE criteria. The mean (±SD) age at time of diagnosis was 28.6 ± 12.4 years. The crude incidence ratio (per 100,000 population) was 3.5, 1.1, 2.1 and 2.1 in years 2009, 2010, 2011, 2012, respectively. The age-standardized incidence per 100,000 population for the four years was 8.6 (95% confidence interval 4.2-15.9). The age-standardized prevalence of SLE among the native population according to the 2012 population consensus was 103/100,000 population (95% confidence interval 84.5-124.4). Conclusion The age-adjusted incidence and prevalence among UAE Arabs is higher than has been reported among most other Caucasian populations. Furthermore, the prevalence of SLE in UAE seems much higher than other similar Arab countries in the Gulf region.

Immunology of neuromyelitis optica during pregnancy

Anti–aquaporin-4 (AQP4) autoantibody plays a key role in the pathogenesis of neuromyelitis optica (NMO). Studies have shown increased relapse rates in patients with NMO during pregnancy and postpartum. High estrogen levels during pregnancy can increase activation-induced cytidine deaminase expression, which is responsible for immunoglobulin production. Additionally, sex hormones may influence antibody glycosylation, with effects on antibody function. Estrogen decreases apoptosis of self-reactive B cells, through upregulation of antiapoptotic molecules. Furthermore, high estrogen levels during pregnancy can boost B-cell activating factor and type 1 interferon (IFN) production, facilitating development of self-reactive peripheral B cells in association with increased disease activity. Elevated levels of estrogen during pregnancy decrease IFN-γ generation, which causes a shift toward T helper (Th) 2 immunity, thereby propagating NMO pathogenesis. Women with NMO have an elevated rate of pregnancy complications including miscarriage and preeclampsia, which are associated with increased Th17 cells and reduction of T-regulatory cells. These in turn can enhance inflammation in NMO. Increased regulatory natural killer cells (CD56⁻) during pregnancy can enhance Th2-mediated immunity, thereby increasing inflammation. In the placenta, trophoblasts express AQP4 antigen and are exposed to maternal blood containing anti-AQP4 antibodies. Animal models have shown that anti-AQP4 antibodies can bind to AQP4 antigen in placenta leading to complement deposition and placental necrosis. Reduction of regulatory complements has been associated with placental insufficiency, and it is unclear whether these are altered in NMO. Further studies are required to elucidate the specific mechanisms of disease worsening, as well as the increased rate of complications during pregnancy in women with NMO.

Endometriosis and the risks of systemic lupus erythematosus and rheumatoid arthritis in the Nurses' Health Study II

OBJECTIVES

The aetiologies of endometriosis, systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA) are all characterised by immune dysfunction. SLE and RA occur more often in women, and reproductive and hormonal factors have been shown to be related to increased risk. However, only one previous study has evaluated the temporal association between endometriosis and SLE or RA. We sought to investigate the association between laparoscopically confirmed endometriosis and subsequently diagnosed SLE and RA.

METHODS

We analysed data from the Nurses' Health Study II (n=114 453 women) over a 22-year follow-up period. Multivariable, time-varying Cox proportional hazards models were used to calculate HRs and 95% CIs for the association between laparoscopically confirmed endometriosis and confirmed incident SLE or RA.

RESULTS

From 1989 to 2011, 103 incident cases of SLE and 390 cases of RA were confirmed. Laparoscopically confirmed endometriosis was significantly associated with subsequent SLE diagnosis (HR=2.03; CI 1.17 to 3.51) and RA diagnosis (HR=1.41; CI 1.05 to 1.89). These associations were robust to adjustment for SLE or RA risk factors and for potential confounders; however, adjustment for hysterectomy and oophorectomy attenuated both relations such that they were no longer significant. No significant differences by infertility status or age (<45 years) were observed.

CONCLUSIONS

Our findings suggest an association between endometriosis and risk of SLE and RA. It remains to be understood whether and how endometriosis itself, or hysterectomy or other factors associated with endometriosis, is related to risk of SLE or RA.

Association between rs2431697 T allele on 5q33.3 and systemic lupus erythematosus: case-control study and meta-analysis

rs2431697 is located on 5q33.3, between pituitary tumor-transforming gene 1 and miR-146a. Several studies have estimated the association between rs2431697 and systemic lupus erythematosus risk. However, the results were inconsistent. A case-control study was carried out to explore the association between rs2431697 and systemic lupus erythematosus risk in a central Chinese population. Meta-analyses combining present with previous studies were conducted to further explore the association. Our case-control study included 322 cases and 353 controls. rs2431697 T allele was associated with increased risk of systemic lupus erythematosus (odds ratios (ORs) = 1.461, 95 % confidence intervals (CI) 1.091–1.957, P = 0.011). The association was stronger between T allele and the risk of anti-double-stranded DNA (dsDNA)-positive systemic lupus erythematosus (OR = 2.510, 95 % CI 1.545–4.077, P < 0.001). The meta-analyses included 8648 systemic lupus erythematosus patients and 10947 controls. rs2431697 T allele had an overall OR of 1.262 (95 % CI 1.205–1.323, P < 0.001) under fixed-effects model. After stratified by ethnicity, I² reduced from 24.3 to 0 %. T allele had an OR of 1.213 (95 % CI 1.145–1.284, P < 0.001) in European descendant and 1.365 (95 % CI 1.259–1.480, P < 0.001) in Asian under fixed-effects model. Data on women were also extracted, and T allele had an OR of 1.337 (95 % CI 1.162–1.539, P < 0.001) under random-effects model. The pooled ORs were not influenced by each study in sensitivity analyses. There were no publication biases observed in these analyses. The results from our case-control study and the meta-analyses indicate that rs2431697 T allele significantly associates with the increased risk of systemic lupus erythematosus.

Cigarette smoking, antiphospholipid antibodies and vascular events in Systemic Lupus Erythematosus

OBJECTIVE

Smoking can induce autoantibodies in persons who are genetically predisposed to rheumatoid arthritis. We investigated the association between smoking and antiphospholipid antibodies (aPL) in systemic lupus erythematosus (SLE), a question not previously addressed. Further, we explored the relationship between smoking, aPL and vascular events (arterial and venous, VE).

METHODS

In this cross-sectional study, clinical evaluation and questionnaire data were collected from 367 prevalent SLE patients. At the same time, we measured aPL (anticardiolipin (aCL), anti-β2 glycoprotein-1 (aβ2GP1) antibodies IgG/IgM/IgA, and lupus anticoagulant (LA)), and a large set of other SLE-associated autoantibodies for comparison. Association analyses using logistic regression models with smoking, (ever, former and current with never as reference) and antibody status as outcome variable were performed. As a secondary outcome, we investigated the associations between aPL, smoking and VE.

RESULTS

In multivariable-adjusted models ever, and in particular former, cigarette smoking was associated with the most pathogenic aPL; LA, aCL IgG and aβ2GP1 IgG. Other SLE-associated autoantibodies were not associated with smoking. The combination of smoking and aPL was strongly associated with VE. We noted a positive interaction between smoking-LA and smoking-'triple aPL' positivity for previous VE.

CONCLUSIONS

We investigated a large set of commonly occurring autoantibodies in SLE, but only aPL were positively associated with a history of smoking. This association was especially apparent in former smokers. Among ever regular smokers who were aPL positive, we observed a strikingly high frequency of former VE. The underlying mechanisms and temporality between smoking, aPL and VE need further investigations.

Epidemiology research in rheumatology-progress and pitfalls

Epidemiology research is a vital component of clinical studies in all medical fields. This Review provides a brief introduction to the methodology and interpretation of population and clinical epidemiology studies of musculoskeletal disorders. Data sources (including 'big data' and the issue of missing data), study design (cross-sectional, case-control and cohort studies, including clinical trial design) and the interpretation of study results are discussed with examples from the field of rheumatology, particularly using findings in patients with rheumatoid arthritis. Two or more treatments can be compared in clinical trials using a variety of study designs including superiority, noninferiority or equivalence. The different types of risk in epidemiological studies-absolute, attributable, background and relative-are important concepts in epidemiological research and their relative usefulness to clinicians and patients should be considered carefully. The potential pitfalls and challenges of generalizing the results of epidemiological studies to understanding disease aetiology and to clinical practice are also emphasized. The aim of the Review is to help readers to critically appraise published articles that use epidemiological designs or methods.

Puberty and perimenopause: reproductive transitions and their implications for women's health

This scoping review synthesizes existing research on two major transitions in females' lives: puberty and perimenopause. These two periods of vast physiological change demarcate the beginning and the end of the reproductive life cycle and are associated with major neuroendocrine reorganization across two key systems, the hypothalamic-pituitary-gonadal (HPG) axis the hypothalamus-pituitary-adrenal (HPA) axis. Despite growing evidence suggesting that the timing and experience of puberty and perimenopause are related to various physical and mental health outcomes (e.g., mood disorders, metabolism, cardiovascular health, autoimmune conditions, and cancer), these two processes are rarely examined together. In this paper, we bridge these disparate literatures to highlight similarities, isolate inconsistencies, and identify important areas for future research in women's health.

EBV and Autoimmunity

Although a role of EBV in autoimmunity is biologically plausible and evidence of altered immune responses to EBV is abundant in several autoimmune diseases, inference on causality requires the determination that disease risk is higher in individuals infected with EBV than in those uninfected and that in the latter it increases following EBV infection. This determination has so far been possible only for multiple sclerosis (MS) and, to some extent, for systemic lupus erythematosus (SLE), whereas evidence is either lacking or not supportive for other autoimmune conditions. In this chapter, we present the main epidemiological findings that justify the conclusion that EBV is a component cause of MS and SLE and possible mechanisms underlying these effects.

Genetics, environment, and gene-environment interactions in the development of systemic rheumatic diseases

Rheumatic diseases offer distinct challenges to researchers because of heterogeneity in disease phenotypes, low disease incidence, and geographic variation in genetic and environmental factors. Emerging research areas, including epigenetics, metabolomics, and the microbiome, may provide additional links between genetic and environmental risk factors in the pathogenesis of rheumatic disease. This article reviews the methods used to establish genetic and environmental risk factors and studies gene-environment interactions in rheumatic diseases, and provides specific examples of successes and challenges in identifying gene-environment interactions in rheumatoid arthritis, systemic lupus erythematosus, and ankylosing spondylitis. Emerging research strategies and future challenges are discussed.

The expression of renal Epstein-Barr virus markers in patients with lupus nephritis

The aim of this study was to investigate the role of renal Epstein-Barr virus (EBV) infection in the pathogenesis of lupus nephritis (LN). A total of 58 renal tissue samples from patients with LN, seven normal renal tissue samples from patients with non-glomerular hematuria and 37 renal tissue samples from patients with minimal change nephropathy were collected. The expression of EBV-latent membrane protein-1 (EBV-LMP1) and EBV-encoded RNA 1 (EBER-1) in the renal tissue was examined by immunohistochemistry (IHC) and in situ hybridization (ISH), respectively. The sera levels of anti-nuclear antibody as well as antibodies to extractable nuclear antigen in patients with LN were also measured. An equivalence test showed that the results from the IHC and the ISH analyses had strong agreement. The positive rates of renal EBER-1 and EBV-LMP1 in the LN patients were significantly higher than those of the normal and minimal change nephropathy patients (P<0.001), while no significant difference was identified between those of the normal and minimal change nephropathy groups (P>0.05). The positive rates of EBV-LMP1 and EBER-1 in the renal tissues of patients with LN were not determined to be significantly different between the relapse (immunosuppressant-treated) and initial onset (non-treated) patients, between the patients with and without concurrent infection, and among the patients with different age ranges (P>0.05). The proportion of LN patients positive for anti-Sm antibody was significantly higher in the renal EBV-positive group than in the EBV-negative group (P<0.05), while the proportions of LN patients positive for the other autoantibodies that were examined were not identified to be significantly different between these two groups (P>0.05). The present study shows that renal EBV infection may contribute to the pathogenesis of LN by inducing anti-Sm antibody production.

Tracing environmental markers of autoimmunity: introducing the infectome

We recently introduced the concept of the infectome as a means of studying all infectious factors which contribute to the development of autoimmune disease. It forms the infectious part of the exposome, which collates all environmental factors contributing to the development of disease and studies the sum total of burden which leads to the loss of adaptive mechanisms in the body. These studies complement genome-wide association studies, which establish the genetic predisposition to disease. The infectome is a component which spans the whole life and may begin at the earliest stages right up to the time when the first symptoms manifest, and may thus contribute to the understanding of the pathogenesis of autoimmunity at the prodromal/asymptomatic stages. We provide practical examples and research tools as to how we can investigate disease-specific infectomes, using laboratory approaches employed from projects studying the “immunome” and “microbiome”. It is envisioned that an understanding of the infectome and the environmental factors that affect it will allow for earlier patient-specific intervention by clinicians, through the possible treatment of infectious agents as well as other compounding factors, and hence slowing or preventing disease development.

Epigenetic modulation of RFC1, MHC2TA and HLA-DR in systemic lupus erythematosus: association with serological markers and six functional polymorphisms of one-carbon metabolic pathway

The current study was conducted to elucidate the effect of genetic variations in one-carbon metabolism on the epigenetic regulation of major histocompatibility complex II transactivator (MHC2TA), reduced folate carrier 1 (RFC1/SLC19A1) and human leukocyte antigen (HLA)-DR in systemic lupus erythematosus (SLE). PCR-RFLP/AFLP, bisulfite-sequencing and real-time PCR approaches were used for genetic, epigenetic and expression analysis respectively. SLE cases exhibited elevated plasma homocysteine levels compared to healthy controls (24.93 ± 1.3 vs. 11.67 ± 0.48 μmol/l), while plasma folate levels showed no association (7.10 ± 2.49 vs. 7.64 ± 2.09 ng/ml). The RFC1 80G>A polymorphism showed 1.32-fold risk (95% CI: 1.02-1.72) for SLE, while glutamate carboxypeptidase II (GCPII) 1561C>T showed reduced risk (OR: 0.47, 95% CI: 0.24-0.90). The expression of RFC1 (0.37 ± 0.09 vs. 0.60 ± 0.17) and HLA-DR (0.68 ± 0.17 vs. 0.98 ± 0.02) was down regulated in the SLE cases. The hypermethylation of RFC1 as observed in the current study may contribute for its down regulation. Plasma folate and thymidylate synthase (TYMS) 5'-UTR 28 bp tandem repeat showed an inverse association with methylation of RFC1 and MHC2TA. SLE cases with hypocomplementemia showed hypermethylation of RFC1, hypomethylation/up regulation of MHC2TA and down regulation of HLA-DR. The hypermethylation of MHC2TA and down regulation of RFC1, MHC2TA and HLA-DR were observed in anti-cardiolipin antibody positive SLE cases. The up regulation of RFC1 and HLA-DR was observed in anti-dsDNA antibody positive SLE cases. The hypomethylation/upregulation of RFC1 and MHC2TA was observed in anti-RNP antibody positive cases. To conclude, one-carbon genetic variants influence epigenetic of MHC2TA and RFC1, thus contributing to phenotypic heterogeneity of SLE.

Infectome: a platform to trace infectious triggers of autoimmunity

The "exposome" is a term recently used to describe all environmental factors, both exogenous and endogenous, which we are exposed to in a lifetime. It represents an important tool in the study of autoimmunity, complementing classical immunological research tools and cutting-edge genome wide association studies (GWAS). Recently, environmental wide association studies (EWAS) investigated the effect of environment in the development of diseases. Environmental triggers are largely subdivided into infectious and non-infectious agents. In this review, we introduce the concept of the "infectome", which is the part of the exposome referring to the collection of an individual's exposures to infectious agents. The infectome directly relates to geoepidemiological, serological and molecular evidence of the co-occurrence of several infectious agents associated with autoimmune diseases that may provide hints for the triggering factors responsible for the pathogenesis of autoimmunity. We discuss the implications that the investigation of the infectome may have for the understanding of microbial/host interactions in autoimmune diseases with long, pre-clinical phases. It may also contribute to the concept of the human body as a superorganism where the microbiome is part of the whole organism, as can be seen with mitochondria which existed as microbes prior to becoming organelles in eukaryotic cells of multicellular organisms over time. A similar argument can now be made in regard to normal intestinal flora, living in symbiosis within the host. We also provide practical examples as to how we can characterise and measure the totality of a disease-specific infectome, based on the experimental approaches employed from the "immunome" and "microbiome" projects.

Increased risk of systemic lupus erythematosus in 29,000 patients with biopsy-verified celiac disease

OBJECTIVE

To investigate a possible association between celiac disease (CD) and systemic lupus erythematosus (SLE). Case series have indicated a possible association, but population-based studies are lacking.

METHODS

We compared the risk of SLE in 29,048 individuals with biopsy-verified CD (villous atrophy, Marsh 3) from Sweden's 28 pathology departments with that in 144,352 matched individuals from the general population identified through the Swedish Total Population Register. SLE was defined as having at least 2 records of SLE in the Swedish Patient Register. We used Cox regression to estimate hazard ratios (HR) for SLE.

RESULTS

During followup, 54 individuals with CD had an incident SLE. This corresponded to an HR of 3.49 (95% CI 2.48-4.90), with an absolute risk of 17/100,000 person-years and an excess risk of 12/100,000. Beyond 5 years of followup, the HR for SLE was 2.54 (95% CI 1.57-4.10). While SLE was predominantly female, we found similar risk estimates in men and women. When we restricted our outcome to individuals who also had a dispensation for a medication used in SLE, the HR was 2.43 (95% CI 1.22-4.87). The HR for having 2 records of SLE diagnoses, out of which at least 1 had occurred in a department of rheumatology, nephrology/dialysis, internal medicine, or pediatrics, was 2.87 (95% CI 1.97-4.17).

CONCLUSION

Individuals with CD were at a 3-fold increased risk of SLE compared to the general population. Although this excess risk remained more than 5 years after CD diagnosis, absolute risks were low.

Health-related quality of life in patients with systemic lupus erythematosus and proliferative lupus nephritis

This study investigated the influence of two different treatments for a kidney inflammation (i.e. proliferative lupus nephritis) on health-related quality of life (HRQoL) in patients with the chronic auto-immune disease systemic lupus erythematosus (SLE). One treatment protocol, the National Institutes of Health (NIH) protocol, was characterized by a high dose of cyclophosphamide (CYC, an immunosuppressive drug), and the second treatment, the Euro-Lupus protocol, involved a low-dose CYC. Thirty-two SLE patients were included based on the received treatment for an episode of proliferative lupus nephritis, according to either the Euro-Lupus or the NIH protocol. The two groups were compared on HRQoL as measured by the SF-36 and the SLE Symptom Checklist (SSC). The Euro-Lupus group (N = 16) tended to show a higher HRQoL than the NIH group (N = 16) on four of seven scales of the SF-36. In addition, the Euro-Lupus group experienced less burden from nausea or vomiting than the NIH group as assessed by the SSC. Fatigue was the most disturbing symptom in both groups. The most burdensome aspects of treatment were related to chemotherapy (55.2%) and use of prednisone (34.5%). Patients with a low HRQoL and high levels of fatigue were more likely to have low levels of serum complement C4 (i.e. elevated immune activity). In conclusion, patients who are treated according to the Euro-Lupus protocol may experience a higher HRQoL than patients who receive the NIH treatment. However, chemotherapy remains burdensome in the low-dose treatment regimen. Potential interventions to further enhance the HRQoL in SLE patients with proliferative lupus nephritis are discussed.

Resistin levels in lupus and associations with disease-specific measures, insulin resistance, and coronary calcification

OBJECTIVE

To evaluate levels of resistin in female subjects with systemic lupus erythematosus (SLE) compared to age and race-matched controls and to determine the relationship between resistin and systemic inflammation, disease measures, and coronary artery calcification (CAC).

METHODS

Resistin levels were measured on stored samples from 159 women with SLE and 70 controls as an extension of a previous cross-sectional study. Spearman correlations and multivariable regressions were used to examine whether resistin levels were associated with SLE, disease-specific and inflammatory markers, insulin resistance, and CAC.

RESULTS

In a multivariable linear regression model, a diagnosis of SLE was significantly associated with higher resistin levels independent of age, race, renal function, body mass index (BMI), high-sensitivity CRP (hsCRP), hypertension, diabetes, and steroid use. In SLE, resistin levels correlated positively with Systemic Lupus International Collaborating Clinics Damage Index, glomerular filtration rate (GFR), hsCRP, erythrocyte sedimentation rate, homocysteine, and disease duration (all p < 0.03). Resistin level did not correlate with markers of insulin resistance or body adiposity, including homeostatic model assessment or BMI. Resistin levels were significantly elevated in SLE cases with CAC compared to cases without CAC (16.58 vs 13.10 ng/ml, respectively; p = 0.04). In multivariate logistic regression, the association was not present after adjustment for age, race, and GFR.

CONCLUSION

SLE was independently associated with higher resistin levels. Among subjects with SLE, higher resistin level correlated positively with renal dysfunction, inflammatory markers, and disease damage but not with insulin resistance or BMI. SLE cases with CAC had higher resistin levels than cases without CAC; however, this relationship was dependent on other established risk factors.

Social support and health in patients with systemic lupus erythematosus: A literature review

In the last decades, with the improvement of life expectancies for systemic lupus erythematosus (SLE) patients, the relationship between social support and health in this population has received a considerable amount of attention in behavioural medicine and health psychology. This paper is the first to review research studies which specifically investigated perceived social support in relation to SLE patients’ health outcomes (quality of life, disease activity and damage). Starting with a descriptive approach to social support perceived by patients with SLE, the research evidence on the impact of social support on health is presented. These studies demonstrate that the consideration of social support is critical in predicting disease activity, damage and quality of life (both physical and psychological components) although the precise ways in which social support contributes to health are not yet completely understood. Discussing the results, the authors offer some suggestions which could guide further research in this field. Finally, clinical and non-clinical implications of the findings are discussed.

Mycoplasmal lipid-associated membrane proteins and Mycoplasma arthritidis mitogen recognition by serum antibodies from patients with rheumatoid arthritis

Mycoplasmal lipid-associated membrane proteins (LAMPs) and Mycoplasma arthritidis mitogen (MAM superantigen) are potent stimulators of the immune system. The objective of this work was to detect antibodies to MAM and LAMPs of Mycoplasma hominis and M. fermentans in the sera of patients affected by rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) to identify mycoplasmal products that can be involved in the etiopathogenesis of these autoimmune diseases. Serum samples from female RA and SLE patients and controls, recombinant MAM, and LAMPs of M. hominis PG21 and M. fermentans PG18 were used in Western blot assays. A similar frequency of sera from patients and controls reactive to MAM was detected. A larger number of M. hominis and M. fermentans LAMPs were recognized by sera from RA patients than controls, but no differences were detected between sera from SLE patients and controls. Among the LAMPs recognized by IgG antibodies from RA patients, proteins of molecular masses in a range of <49 and ≥20 KDa (M. hominis) and <102 and ≥58 KDa (M. fermentans) were the most reactive. These preliminary results demonstrate the strong reactivity of antibodies of RA patients with some M. hominis and M. fermentans LAMPs. These LAMPs could be investigated as mycoplasmal antigens that can take part in the induction or amplification of human autoimmune responses.

Lethal manifestations of systemic lupus erythematosus in a forensic context

Systemic lupus erythematosus is an autoimmune connective tissue disorder that affects multiple organs. While the clinical manifestations may vary in intensity over time and be associated with chronic disease, occasional cases occur where sudden and unexpected death has occurred. Cardiovascular disease is common, with accelerated atherosclerosis, intravascular thrombosis associated with antiphospholipid syndrome, and hypertensive cardiomegaly. Vasculitis with superimposed thrombosis may result in critical reduction in blood to vital organs, such as the heart and brain with infarction. Mesenteric ischemia may be caused by vasculitis, thrombosis, and accelerated atherosclerosis and may result in lethal intestinal infarction. Other diverse causes of sudden death include myocarditis, epilepsy, pulmonary hypertension, pulmonary thromboembolism, and sepsis. The autopsy evaluation of such cases requires careful examination of all organs with extensive histological sampling to include blood vessels, and microbiological sampling for bacteria, viruses, and fungi.

Autoimmune disease incidence among women prenatally exposed to diethylstilbestrol

OBJECTIVE

Animal studies have suggested that prenatal diethylstilbestrol (DES) exposure may alter immune system development and function including antigen self-recognition. A cohort study was conducted to investigate whether prenatal DES exposure might influence the incidence of at least some specific autoimmune diseases in women.

METHODS

A group of women who were and were not prenatally exposed to DES have been followed for more than 25 years for numerous health outcomes including autoimmune disease. To verify diagnoses, medical records or physician abstracts were requested for all women who reported a diagnosis of rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), optic neuritis (ON), and idiopathic thrombocytopenic purpura (ITP). Incidence rates of these autoimmune diseases were compared between women who were and who were not prenatally DES-exposed.

RESULTS

Overall, there was no increase in verified autoimmune disease among DES-exposed women relative to those who were not exposed (RR 1.2; 95% CI 0.7, 2.1). There was, however, a positive association between prenatal DES exposure and RA among women younger than 45 years (RR 4.9; 95% CI 1.1, 21.6) and an inverse association among women who were 45 years and older (RR 0.1; 95% CI 0.01, 0.7).

CONCLUSION

Overall, these data provide little support for an association between prenatal DES exposure and development of autoimmune disease. The implication that such exposure may be related to RA in an unusual age-related manner is based on small numbers of cases and warrants further study.

IFN regulatory factor 5 is required for disease development in the FcgammaRIIB-/-Yaa and FcgammaRIIB-/- mouse models of systemic lupus erythematosus

Polymorphisms in the transcription factor IFN regulatory factor 5 (IRF5) are strongly associated in human genetic studies with an increased risk of developing the autoimmune disease systemic lupus erythematosus. However, the biological role of IRF5 in lupus pathogenesis has not previously been tested in an animal model. In this study, we show that IRF5 is absolutely required for disease development in the FcgammaRIIB(-/-)Yaa and FcgammaRIIB(-/-) lupus models. In contrast to IRF5-sufficient FcgammaRIIB(-/-)Yaa mice, IRF5-deficient FcgammaRIIB(-/-)Yaa mice do not develop lupus manifestations and have a phenotype comparable to wild-type mice. Strikingly, full expression of IRF5 is required for the development of autoimmunity, as IRF5 heterozygotes had dramatically reduced disease. One effect of IRF5 is to induce the production of the type I IFN, IFN-alpha, a cytokine implicated in lupus pathogenesis. To address the mechanism by which IRF5 promotes disease, we evaluated FcgammaRIIB(-/-)Yaa mice lacking the type I IFN receptor subunit 1. Unlike the IRF5-deficient and IRF5-heterozygous FcgammaRIIB(-/-)Yaa mice, type I IFN receptor subunit 1-deficient FcgammaRIIB(-/-)Yaa mice maintained a substantial level of residual disease. Furthermore, in FcgammaRIIB(-/-) mice lacking Yaa, IRF5-deficiency also markedly reduced disease manifestations, indicating that the beneficial effects of IRF5 deficiency in FcgammaRIIB(-/-)Yaa mice are not due only to inhibition of the enhanced TLR7 signaling associated with the Yaa mutation. Overall, we demonstrate that IRF5 plays an essential role in lupus pathogenesis in murine models and that this is mediated through pathways beyond that of type I IFN production.

Induction of autoimmunity in Brown Norway rats by oral and parenteral administration of sodium silicate

Silica and silicate may disturb immune function such as autoimmunity and tumour immunity. The main objective of this study was to examine the relation between sodium silicate and induction of autoimmunity in genetically susceptible rats. In this study, thirty Brown Norway rats were randomised into four treatment groups, the first and second group receiving 3 mg of sodium silicate (NaSiO(4)) (equivalent to 2 mg silica) in 0.2 mL of normal saline either per oral or subcutaneously, and the third and fourth group (control) receiving 0.2 mL of normal saline (0.9%) through the same corresponding route. A significant number of rats (80%) (P < 0.05) which received sodium silicate by the subcutaneous route showed a high level of serum ANA compared with controls. In the oral, sodium silicate group showed high serum ANA in an insignificant number of rats. Other autoantibodies in both groups (anti-dsDNA, anti-Smith, anti-SSA, anti-SSB) showed gradual increased post exposure, but the numbers of rats with positive titres post exposure was statistically not significant. Silica exposure in rats appears to induce the development of autoimmunity. A longer duration post exposure to silicate seems to be associated with greater risks.

The role of B lymphocyte stimulator (BLyS) in systemic lupus erythematosus

SLE, a chronic, multisystem autoimmune disorder with a broad range of symptoms, involves defective B cell selection and elimination of self-reactive B cells. B lymphocyte stimulator (BLyS), a soluble ligand of the TNF cytokine family, is a prominent factor in B cell differentiation, homeostasis, and selection. BLyS levels affect survival signals and selective apoptosis of autoantibody-producing B cells. High levels of BLyS may relax B cell selection and contribute to autoantibody production, exacerbating the SLE disease state. This review discusses the mechanism of BLyS action on B cells, its role in SLE, and specific targeting of BLyS in the treatment of SLE.

Alcohol consumption is not protective for systemic lupus erythematosus

OBJECTIVE

Several studies have suggested that alcohol drinking is protective for the development and progression of systemic lupus erythematosus (SLE). However, a protopathic bias might also explain this apparent association. Our objective was to investigate the association between alcohol consumption and incidence of SLE in a data set that has information on both current and pre-diagnostic alcohol consumption.

METHODS

We performed an Internet-based case-control study of SLE. Cases were diagnosed within 5 years of the study and met > or =4 American College of Rheumatology criteria for SLE. The control participants were tightly matched to cases on demographic and socio-economic characteristics using a propensity score. Participants completed an online exposure assessment. We used conditional logistic regression analyses to test the association of current and pre-diagnostic alcohol consumption with SLE.

RESULTS

The sample comprised 114 cases with SLE and 228 matched controls. Current drinking (>2 days per week) was inversely associated with SLE (OR 0.35, 95% CI 0.13 to 0.98). Having more than two drinks per day was also inversely associated with SLE (OR 0.41, 95% CI 0.18 to 0.93). However, alcohol consumption before SLE diagnosis was not associated with the risk of SLE (p> or =0.4). Analysis of the change in drinking habits showed that people with lupus were more likely to quit drinking before (OR 2.25, 95% CI 0.96 to 5.28) or after (OR 2.38, 95% CI 0.88 to 6.49) being given the SLE diagnosis.

CONCLUSIONS

Our results show that alcohol consumption before SLE diagnosis is not associated with the risk for SLE, and that individuals who develop SLE are more likely to quit.

27-Hydroxycholesterol: a potential endogenous regulator of estrogen receptor signaling

The selective estrogen receptor modulators (SERMs) are synthetic pharmaceuticals, the relative agonist and antagonist activities of which are not equivalent in all cells. Their discovery has raised the possibility that endogenous small molecules might exist that have similar properties and could have important physiological roles. In support of this hypothesis is the recent demonstration that the oxysterol 27-hydroxycholesterol (27HC) interacts with and modulates the transcriptional activity of both estrogen receptor (ER) subtypes and that the relative agonist and antagonist activity of 27HC is influenced by both cell and promoter context. Although there is limited information available on the role of 27HC in classical estrogen-responsive tissues, that which is available in animal models of cardiovascular disease and cellular models of breast cancer support a role for this ligand in ER signaling. These results provide an interesting potential link between cholesterol (and cholesterol metabolism) and ER function, the physiological and pathological importance of which remains to be determined.