Cigarette smoking and autoimmune disease: what can we learn from epidemiology?

Hydroquinone exposure worsens the symptomatology of rheumatoid arthritis

The genesis of rheumatoid arthritis (RA) is complex and dependent on genetic background and exposure to environmental xenobiotic. Indeed, smoking is associated to developing and worsening pre-existing RA. Nevertheless, the mechanisms and cigarette compounds involved in the harmful processes have not been elucidated. Here, we investigated if the exposure to hydroquinone (HQ), an abundant pro-oxidative compound of cigarette and benzene metabolite, could worsen the ongoing RA. Hence, collagen-induced arthritis (CIA) was induced in male Wistar rats by s.c. injection of 400 μg (200 μL) of bovine collagen type II emulsified in complete Freund's adjuvant on day 1, and a booster injection was performed on day 7. Exposures to nebulized HQ (25 ppm), saline solution or HQ vehicle solution (5% ethanol in saline) were carried out for 1 h, once a day, on days 21-27 after CIA induction. On day 27, animals were euthanized and samples were collected for further analyses. Exposure to HQ caused loss of weight, intensified paw edema, enhanced levels of tumor necrosis factor-α (TNF-α) and anti-citrullinated protein antibody (ACPA) in the serum; augmented synoviocyte proliferation and influx of aril hydrocarbon receptor (AhR) positive cells into the synovial membrane, altered collagen fibre rearrangement in the synovia, and synoviocytes isolated from HQ exposed rats secreted higher levels of pro-inflammatory cytokines, TNF-α and interleukin-1β. Associated, we point out HQ as an environmental pollutant that aggravates RA, suggesting its participation on worsening RA in smoking patients.

An observation on the severity of periodontal disease in past cigarette smokers suffering from rheumatoid arthritis- evidence for a long-term effect of cigarette smoke exposure?

Background

Rheumatoid arthritis (RA) and cigarette smoking are both risk factors for periodontal disease (PD). Previous research suggests that systemic inflammatory conditions and cigarette smoking may act in synergy, and their co-occurrence leads to a much higher risk of developing severe stage PD than what the combination of their individual risks would suggest. We originally sought to test this in the case of RA, but it turned out that the majority of our patients were former smokers, who smoked for prolonged periods in the past. For that reason, we decided to shift our focus toward the possible effects of past chronic cigarette smoke exposure.

Methods

The data of 73 RA patients and 77 healthy controls were analyzed. The participants received a full-mouth periodontal examination to determine their periodontal status. Rheumatological indices and data on past tobacco use were also recorded. Both the patient and the control groups were divided into former smoker and non-smoker subgroups for the analyses. Non-smoker controls were used as the reference group.

Results

In the control group, smoking in history increased the odds of developing both the moderate and the severe stages of PD, but the change was not statistically significant. RA significantly, increased the odds of developing both stages in itself, but the highest odds were seen in the former smoker RA group.

Conclusion

Based on this surprising observation of ours, we hypothesize that chronic cigarette smoke might bring about permanent changes in the periodontal tissues, leading to their hypersensitivity to inflammatory challenges.

Epigenetic changes and their implications in autoimmune hepatitis

BACKGROUND

The genetic risk of autoimmune hepatitis is insufficient to explain the observed risk, and epigenetic changes may explain disparities in disease occurrence in different populations within and between countries. The goal of this review was to examine how epigenetic changes induced by the environment or inherited as a phenotypic trait may affect autoimmune hepatitis and be amenable to therapeutic intervention.

MATERIALS AND METHODS

Pertinent abstracts were identified in PubMed by multiple search terms. The number of abstracts reviewed was 1689, and the number of full-length articles reviewed exceeded 150.

RESULTS

Activation of pro-inflammatory genes in autoimmune disease is associated with hypomethylation of deoxyribonucleic acid and modification of histones within chromatin. Organ-specific microribonucleic acids can silence genes by marking messenger ribonucleic acids for degradation, and they can promote inflammatory activity or immunosuppression. High circulating levels of the microribonucleic acids 21 and 122 have been demonstrated in autoimmune hepatitis, and they may increase production of pro-inflammatory cytokines. Microribonucleic acids are also essential for maintaining regulatory T cells. Drugs, pollutants, infections, diet and ageing can induce inheritable epigenetic changes favouring autoimmunity. Reversal is feasible by manipulating enzymes, transcription factors, gene-silencing molecules and toxic exposures or by administering methyl donors and correcting vitamin D deficiency. Gene targets, site specificity, efficacy and consequences are uncertain.

CONCLUSIONS

Potentially reversible epigenetic changes may affect the occurrence and outcome of autoimmune hepatitis, and investigations are warranted to determine the nature of these changes, key genomic targets, and feasible interventions and their consequences.

Anti-phospholipid Antibodies and Smoking: An Overview

Antiphospholipid syndrome is characterized by the presence of antiphospholipid antibodies, specifically lupus anticoagulant, anticardiolipin antibodies, and anti-β2 glycoprotein-I antibodies. Antiphospholipid syndrome can occur on its own or in association with other autoimmune diseases, most commonly systemic lupus erythematosus (SLE). A connection between cigarette smoking and anti-phospholipid antibodies (aPL) was first reported in the late1980s. Systemic lupus erythematosus patients with aPL are more likely to be smokers than those without aPL. These patients have a particularly high frequency of vascular events. Recently, a potential link between periodontitis, tobacco, and aPL has been proposed. Research has also suggested that periodontitis and Porphyromonas gingivalis infection are associated with citrullination through the action of peptidylarginine deiminase. A strong correlation between smoking and the presence of citrillunated autoantibodies, which are characteristic of rheumatoid arthritis, has also been observed. While many studies have investigated possible links between infection and aPL in patients with autoimmune diseases, the association of smoking with aPL has not been systematically examined. The fact that both aPL and tobacco are risk factors for thrombosis has complicated efforts to evaluate these factors separately. Also, there has been great variability in measurement techniques, and laboratories lack routine methods for differentiating transient and persistent aPL; both of these factors can make interpretation of autoantibody results quite challenging. This review summarizes the clinical evidence supporting a posited link between aPL and smoking, both in patients with a systemic autoimmune disease and in patients with other medical conditions.

Immune Dysregulation in Cancer Patients Undergoing Immune Checkpoint Inhibitor Treatment and Potential Predictive Strategies for Future Clinical Practice

Realization of the full potential of immune checkpoint inhibitor-targeted onco-immunotherapy is largely dependent on overcoming the obstacles presented by the resistance of some cancers, as well as on reducing the high frequency of immune-related adverse events (IRAEs) associated with this type of immunotherapy. With the exception of combining therapeutic monoclonal antibodies, which target different types of immune checkpoint inhibitory molecules, progress in respect of improving therapeutic efficacy has been somewhat limited to date. Likewise, the identification of strategies to predict and monitor the development of IRAEs has also met with limited success due, at least in part, to lack of insight into mechanisms of immunopathogenesis. Accordingly, considerable effort is currently being devoted to the identification and evaluation of strategies which address both of these concerns and it is these issues which represent the major focus of the current review, particularly those which may be predictive of development of IRAEs. Following an introductory section, this review briefly covers those immune checkpoint inhibitors currently approved for clinical application, as well as more recently identified immune checkpoint inhibitory molecules, which may serve as future therapeutic targets. The remaining and more extensive sections represent overviews of: (i) putative strategies which may improve the therapeutic efficacy of immune checkpoint inhibitors; (ii) recent insights into the immunopathogenesis of IRAEs, most prominently enterocolitis; and (iii) strategies, mostly unexplored, which may be predictive of development of IRAEs.

Anti-endothelial cell antibody rich sera from rheumatic heart disease patients induces proinflammatory phenotype and methylation alteration in endothelial cells

Rheumatic heart disease (RHD) is a major cause of cardiovascular morbidity and mortality in developing nations like India. RHD commonly affects the mitral valve which is lined by a single layer of endothelial cells (ECs). The role of ECs in mitral valve damage during RHD is not well elucidated. In here, anti-endothelial cell antibody from RHD patients has been used to stimulate the ECs (HUVECs and HMVECs). ECs proinflammatory phenotype with increased expression of TNFα, IL-6, IL-8, IFNγ, IL-1β, ICAM1, VCAM1, E-selectin, laminin B, and vimentin was documented in both ECs. The promoter hypomethylation of various key inflammatory cytokines (TNFα, IL-6, and IL-8), integrin (ICAM1) associated with leukocyte transendothelial migration, and extracellular matrix genes (vimentin, and laminin) were also observed. Further, the in-vitro data was in accordance with ex-vivo observations which correlated significantly with the etiological factors such as smoking, socioeconomic status, and housing. Thus, the study sheds light on the role of ECs in RHD which is a step forward in the elucidation of disease pathogenesis.

Is osteoporosis an autoimmune mediated disorder?

The last two decades have marked a growing understanding of the interaction occurring between bone and immune cells. The chronic inflammation and immune system dysfunction commonly observed to occur during the ageing process and as part of a range of other pathological conditions, commonly associated with osteoporosis has led to the recognition of these processes as important determinants of bone disease. This is further supported by the recognition that the immune and bone systems in fact share regulatory mechanisms and progenitor molecules. Research into this complex synergy has provided a better understanding of the immunopathogenesis underlying bone diseases such as osteoporosis. However, existing research has largely focussed on delineating the role played by inflammation in pathogenic bone destruction, despite increasing evidence implicating autoantibodies as important drivers of osteoporosis. This review shall attempt to provide a comprehensive overview of existing research examining the role played by autoantibodies in osteoporosis in order to determine the potential for further research in this area. Autoantibodies represent promising targets for the improved treatment and diagnosis of inflammatory bone loss.

Comorbidities of Atopic Dermatitis: Beyond Rhinitis and Asthma

PURPOSE OF REVIEW

In this review article, we summarize the current evidence about atopic dermatitis (AD)-associated comorbidities, beyond the traditional atopic and allergic conditions.

RECENT FINDINGS

Patients with AD may have an increased risk of cardiovascular diseases, certain malignancies, autoimmune diseases, and neuropsychiatric diseases. The causes of these associations are likely multifactorial and may include genetic predispositions, systemic low-grade inflammation, environmental exposures, medication, and lifestyle and behavioral risk factors. There appears to be geographical variations in prevalence of comorbidities in patients with AD, indicating that differences in ethnicity and lifestyle factors may significantly influence the risk of certain comorbidities.

SUMMARY

The reported comorbidities in recent literature emphasize the burden of disease in patients with AD. Early appropriate AD therapy, in combination with reduction of risk factors, may help prevention of certain comorbidities. The reported observations may generate hypotheses for future investigations in underlying risk factors for AD-associated comorbidities.

Evaluating the utility of serological testing in laryngotracheal stenosis

OBJECTIVES/HYPOTHESIS

Whereas mechanical (traumatic) causes of laryngotracheal stenosis (LTS) are identified based on history, autoimmune laryngotracheal stenosis (aLTS) and idiopathic laryngotracheal stenosis (iLTS) are often more difficult to differentiate. The objective of this study was to evaluate serologic testing in a large cohort of nonmechanical LTS patients to determine which tests, if any, lead clinicians to the etiology of the LTS.

STUDY DESIGN

Retrospective chart review.

METHODS

This study reviewed nonmechanical LTS patients seen at a tertiary medical center from 2007 to 2014. Data were obtained on patient demographics, associated preexisting autoimmune conditions, comorbidities, intubation history, and serologic testing.

RESULTS

Ninety-two records were reviewed. Twenty-three (25%) patients were found to have autoimmune disease; 69 (75%) met criteria for iLTS. A history of cigarette smoking was more significant in the aLTS group than the iLTS group (P < .001). Antineutrophil cytoplasmic antibody (ANCA) was positive only in patients with known granulomatosis with polyangiitis (GPA). All other serological testing was equivocal between the two cohorts.

CONCLUSIONS

Differentiating iLTS from aLTS has proven difficult. The lack of information about the two entities has resulted in variability in the diagnostic workup to distinguish them. This study's finding of a more significant smoking history in the aLTS group correlates with the literature, which suggests an inflammatory effect of smoking cigarettes and an association with autoimmune disease. The only significant cohort of patients in this study found to have positive serological testing correlated with a diagnosable condition responsible for LTS was GPA patients with positive ANCA.

LEVEL OF EVIDENCE

4. Laryngoscope, 127:1408-1412, 2017.

B cells in chronic obstructive pulmonary disease: moving to center stage

Chronic inflammatory responses in the lungs contribute to the development and progression of chronic obstructive pulmonary disease (COPD). Although research studies focused initially on the contributions of the innate immune system to the pathogenesis of COPD, more recent studies have implicated adaptive immune responses in COPD. In particular, studies have demonstrated increases in B cell counts and increases in the number and size of B cell-rich lymphoid follicles in COPD lungs that correlate directly with COPD severity. There are also increases in lung levels of mediators that promote B cell maturation, activation, and survival in COPD patients. B cell products such as autoantibodies directed against lung cells, components of cells, and extracellular matrix proteins are also present in COPD lungs. These autoantibodies may contribute to lung inflammation and injury in COPD patients, in part, by forming immune complexes that activate complement components. Studies of B cell-deficient mice and human COPD patients have linked B cells most strongly to the emphysema phenotype. However, B cells have protective activities during acute exacerbations of COPD by promoting adaptive immune responses that contribute to host defense against pathogens. This review outlines the evidence that links B cells and B cell-rich lymphoid follicles to the pathogenesis of COPD and the mechanisms involved. It also reviews the potential and limitations of B cells as therapeutic targets to slow the progression of human COPD.

Smoking and the Risk of LADA: Results From a Swedish Population-Based Case-Control Study

OBJECTIVE

Smoking is an established risk factor for type 2 diabetes. In contrast, it has been proposed that smoking may reduce the risk of latent autoimmune diabetes in adults (LADA), but studies are scarce. We aimed to study the impact of smoking on LADA and type 2 diabetes risks.

RESEARCH DESIGN AND METHODS

We used data from a Swedish case-control study including incident case patients with LADA (GAD antibody [GADA] positive, n = 377) and type 2 diabetes (GADA negative, n = 1,188) and control subjects randomly selected from the population (n = 1,472). We calculated odds ratios (ORs) with 95% CIs by logistic regression, adjusted for age, sex, BMI, family history of diabetes, and alcohol consumption.

RESULTS

There was no indication of reduced risk of LADA in smokers; instead, heavy smoking was associated with an increased risk of LADA (OR 1.37, 95% CI 1.02-1.84). Heavy smokers had higher levels of HOMA of insulin resistance (9.89 vs. 4.38, P = 0.0479) and HOMA of β-cell function (55.7 vs. 42.5, P = 0.0204), but lower levels of GADA (75 vs. 250, P = 0.0445), compared with never smokers. Smokers also displayed an increased risk of type 2 diabetes (OR in ever smokers 1.53, 95% CI 1.25-1.88).

CONCLUSIONS

In this large population of LADA patients, we did not observe a protective effect of smoking on autoimmunity and the risk of LADA. A protective effect could possibly be masked by a smoking-induced aggravation of insulin resistance, akin to the diabetogenic effect seen in individuals with type 2 diabetes.

Understanding the Relationship between Chronic Systemic Disease and Lichen Sclerosus Urethral Strictures

PURPOSE

Lichen sclerosus is a chronic, inflammatory skin condition of the genitalia of unknown origin that accounts for nearly 10% of urethral stricture disease. In this study we determine systemic comorbidities associated with lichen sclerosus in men.

MATERIALS AND METHODS

We analyzed data from 1,151 men who were enrolled in a multi-institutional prospective urethroplasty outcomes database. Individuals were grouped by stricture etiology, and baseline demographics, medical histories and patient reported outcome measures were retrospectively compared across groups.

RESULTS

Of the 1,151 men in the database 81 (7.0%) were noted to have lichen sclerosus related urethral stricture disease. Average patient age was 46.06 ± 16.52 years, with those with lichen sclerosus being significantly older than those without lichen sclerosus (51.26 ± 13.84 vs 45.68 ± 16.64, p = 0.0011). Men with lichen sclerosus were more likely to have hypertension, hyperlipidemia and diabetes, and to use tobacco products. Controlling for age, men with lichen sclerosus related urethral stricture disease had a higher body mass index (aOR 1.089, 95% CI 1.050-1.130), and were more likely to have hypertension (aOR 2.028, 1.21-3.41) and be active tobacco users (aOR 2.0, 1.36-3.40). Mean preoperative patient reported outcome measures scores for urinary and sexual function were similar. Controlling for stricture length and location, the adjusted odds of surgical failure were higher for lichen sclerosus related urethral stricture disease (aOR 1.9, 95% CI 0.9-4.2).

CONCLUSIONS

Lichen sclerosus related urethral stricture disease is associated with chronic systemic diseases. This association may implicate a systemic inflammatory and/or autoimmune pathophysiology. A 2-hit mechanism implicating local and systemic factors for lichen sclerosus related urethral stricture disease development and progression is hypothesized.

Relationship between soluble intercellular adhesion molecules and attention-deficit/hyperactivity disorder

OBJECTIVE

Attention-deficit/hyperactivity disorder (ADHD) is a common childhood-oneset psychiatric disease, characterized by excessive overactivity, inattention, and impulsiveness. In recent studies, it is emphasized that inflammation may have a role in ADHD. In this study, we aimed to investigate whether there are associations between ADHD and serum levels of soluble intercellular adhesion molecules (s-ICAMs) which have important role in inflammatory diseases. We also measured the levels of these molecules after treatment with oros-methylphenidate.

METHODS

Twenty-five patients diagnosed with ADHD according to Diagnostic and Statistical Manual of Mental Disorders-IV-TR criteria and 18 healthy volunteer controls were included in this study. The levels of sICAMs were measured in the serum of the patients and healthy volunteers by ELISA kit as described.

RESULTS

The levels of sICAM-1 and sICAM-2 were significantly higher in patients compared with controls. The level of sICAM-2 was decreased significantly in group treated with oros-methylphenidate.

CONCLUSIONS

This is the first study pointing out the relationship between sICAMs and ADHD. The changes in sICAM-2 level may have a role in the effect mechanism of oros-methylphenidate, used for the treatment of ADHD.

Cigarette Smoking and Activities of Daily Living in Ocular Myasthenia Gravis

BACKGROUND

Myasthenia gravis is an autoimmune disease of the neuromuscular junction, commonly affecting the ocular muscles. Cigarette smoking has been shown to influence many autoimmune diseases, including multiple sclerosis and rheumatoid arthritis, but its effect on myasthenia gravis has not been well studied. We sought to determine whether cigarette smoking influenced disease-related symptoms in ocular myasthenia gravis (OMG).

METHODS

We performed a prospective, clinic-based cross-sectional study in a single academic neuro-ophthalmology practice. All patients diagnosed with OMG between November 2006 and April 2014 were included. A prospective telephone survey was administered to determine smoking status and myasthenia gravis-related symptom severity. The main outcome measure was the myasthenia gravis-specific activities of daily living (MG-ADL) score, a well-validated marker of symptoms and quality of life in myasthenia gravis.

RESULTS

Forty-four patients were included in the analysis. Comparison of MG-ADL ocular subscores between current smokers (3.4 ± 2.6), former smokers (1.8 ± 2.1), and never smokers (1.1 ± 1.5) revealed a statistically significant relationship (P = 0.031) where current smokers had the highest MG-ADL ocular subscores and never smokers the lowest. Comparison of MG-ADL total scores revealed the same relationship (current 5.6 ± 4.5, former 2.9 ± 3.1, never 1.4 ± 2.5, P = 0.003). There were borderline significant correlations of pack years with MG-ADL ocular subscore (r = 0.27, P = 0.074) and MG-ADL total score (r = 0.30, P = 0.051).

CONCLUSIONS

Our findings indicate an association between cigarette smoking and symptom severity in OMG. This association suggests that smoking cessation in OMG patients may lead to improved symptom-related quality of life.

Autoimmune and Atopic Disorders and Risk of Classical Hodgkin Lymphoma

Results from previous investigations have shown associations between the risk of Hodgkin lymphoma (HL) and a history of autoimmune and atopic diseases, but it remains unknown whether these associations apply to all types of HL or only to specific subtypes. We investigated immune diseases and the risk of classical HL in a population-based case-control study that included 585 patients and 3,187 controls recruited from October 1999 through August 2002. We collected information on immune diseases through telephone interviews and performed serological analyses of specific immunoglobulin E reactivity. Tumor Epstein-Barr virus (EBV) status was determined for 498 patients. Odds ratios with 95% confidence intervals were calculated using logistic regression analysis. Rheumatoid arthritis was associated with a higher risk of HL (odds ratio (OR) = 2.63; 95% confidence interval (CI): 1.47, 4.70), especially EBV-positive HL (OR = 3.18; 95% CI: 1.23, 8.17), and with mixed-cellularity HL (OR = 4.25; 95% CI: 1.66, 10.90). HL risk was higher when we used proxies of severe rheumatoid arthritis, such as ever having received daily rheumatoid arthritis medication (OR = 3.98; 95% CI: 2.08, 7.62), rheumatoid arthritis duration of 6-20 years (OR = 3.80; 95% CI: 1.72, 8.41), or ever having been hospitalized for rheumatoid arthritis (OR = 7.36; 95% CI: 2.95, 18.38). Atopic diseases were not associated with the risk of HL. EBV replication induced by chronic inflammation in patients with autoimmune diseases might explain the higher risk of EBV-positive HL.

Bayesian Network Inference Enables Unbiased Phenotypic Anchoring of Transcriptomic Responses to Cigarette Smoke in Humans

Microarray-based transcriptomic analysis has been demonstrated to hold the opportunity to study the effects of human exposure to, e.g., chemical carcinogens at the whole genome level, thus yielding broad-ranging molecular information on possible carcinogenic effects. Since genes do not operate individually but rather through concerted interactions, analyzing and visualizing networks of genes should provide important mechanistic information, especially upon connecting them to functional parameters, such as those derived from measurements of biomarkers for exposure and carcinogenic risk. Conventional methods such as hierarchical clustering and correlation analyses are frequently used to address these complex interactions but are limited as they do not provide directional causal dependence relationships. Therefore, our aim was to apply Bayesian network inference with the purpose of phenotypic anchoring of modified gene expressions. We investigated a use case on transcriptomic responses to cigarette smoking in humans, in association with plasma cotinine levels as biomarkers of exposure and aromatic DNA-adducts in blood cells as biomarkers of carcinogenic risk. Many of the genes that appear in the Bayesian networks surrounding plasma cotinine, and to a lesser extent around aromatic DNA-adducts, hold biologically relevant functions in inducing severe adverse effects of smoking. In conclusion, this study shows that Bayesian network inference enables unbiased phenotypic anchoring of transcriptomics responses. Furthermore, in all inferred Bayesian networks several dependencies are found which point to known but also to new relationships between the expression of specific genes, cigarette smoke exposure, DNA damaging-effects, and smoking-related diseases, in particular associated with apoptosis, DNA repair, and tumor suppression, as well as with autoimmunity.

Subsequent Type 2 Diabetes in Patients with Autoimmune Disease

Immunological data show that type 2 diabetes (T2D) manifests autoimmune features. We wanted to test the association epidemiologically by assessing subsequent diagnosis of T2D following diagnosis of autoimmune disease (AId) and subsequent AId after T2D in the same individuals. Patients were identified from three Swedish health databases. A total of 32 different AId were included. Standardized incidence ratios (SIRs) were calculated for T2D diagnosis in patients with previously diagnosed AId and compared to those without a previous AId. Among a total of 757,368 AId patients, 15,103 were diagnosed with T2D, giving an overall SIR for T2D of 1.66. T2D risks were increased after 27 AIds; the highest SIRs were noted for chorea minor (8.00), lupoid hepatitis (5.75), and Addison disease (2.63). T2D was increased after 27 of 32 AIds but we were unable to control for factors such as obesity and smoking. However, the clearly increased risks for T2D in most types of AId patients, and in reverse order increased risks for AId after T2D, do not support an overall confounding by life-style factors. Mechanistic links shared by T2D, AId and life-style factors such as obesity, perhaps through chronic inflammation, may drive autoimmune activation of T2D and many AIds.

Systemic Autoimmune, Rheumatic Diseases and Coinciding Psoriasis: Data from a Large Single-Centre Registry and Review of the Literature

Psoriasis is a systemic immune-inflammatory disease characterized by chronic or recurrent skin symptoms, psoriatic arthritis, enthesopathy, and uveitis. Psoriasis has recently been published to appear with various autoimmune disorders, but the coexistence has been systematically reviewed by only few studies until now. In the present study, charts and electronic database of 4344 patients with various systemic autoimmune disorders, under regular medical control at our department, were reviewed retrospectively searching for association with psoriasis. Hereby, we demonstrate 25 psoriatic patients coinciding with various systemic autoimmune diseases. The coexistence of psoriasis and autoimmune diseases resulted in the worsening of the clinical outcome of the autoimmune diseases as indicated by higher frequency and dosages of glucocorticoid use, need for biologicals, and other comorbidities. These results suggest common environmental and genetic background as well as therapeutic possibilities in the future.

Mercury Exposure and Antinuclear Antibodies among Females of Reproductive Age in the United States: NHANES

BACKGROUND

Immune dysregulation associated with mercury has been suggested, although data in the general population are lacking. Chronic exposure to low levels of methylmercury (organic) and inorganic mercury is common, such as through fish consumption and dental amalgams.

OBJECTIVE

We examined associations between mercury biomarkers and antinuclear antibody (ANA) positivity and titer strength.

METHODS

Among females 16-49 years of age (n = 1,352) from the National Health and Nutrition Examination Survey (NHANES) 1999-2004, we examined cross-sectional associations between mercury and ANAs (indirect immunofluorescence; cutoff ≥ 1:80). Three biomarkers of mercury exposure were used: hair (available 1999-2000) and total blood (1999-2004) predominantly represented methylmercury, and urine (1999-2002) represented inorganic mercury. Survey statistics were used. Multivariable modeling adjusted for several covariates, including age and omega-3 fatty acids.

RESULTS

Sixteen percent of females were ANA positive; 96% of ANA positives had a nuclear speckled staining pattern. Geometric mean (geometric SD) mercury concentrations were 0.22 (0.03) ppm in hair, 0.92 (0.05) μg/L blood, and 0.62 (0.04) μg/L urine. Hair and blood, but not urinary, mercury were associated with ANA positivity (sample sizes 452, 1,352, and 804, respectively), after adjusting for confounders: for hair, odds ratio (OR) = 4.10 (95% CI: 1.66, 10.13); for blood, OR = 2.32 (95% CI: 1.07, 5.03) comparing highest versus lowest quantiles. Magnitudes of association were strongest for high-titer (≥ 1:1,280) ANA: hair, OR = 11.41 (95% CI: 1.60, 81.23); blood, OR = 5.93 (95% CI: 1.57, 22.47).

CONCLUSIONS

Methylmercury, at low levels generally considered safe, was associated with subclinical autoimmunity among reproductive-age females. Autoantibodies may predate clinical disease by years; thus, methylmercury exposure may be relevant to future autoimmune disease risk.

Smoking and the risk of systemic lupus erythematosus: an updated systematic review and cumulative meta-analysis

Published articles reported controversial results about the association of smoking with the risk of systemic lupus erythematosus (SLE). A meta-analysis was performed to assess the aforementioned association and arrive at a more precise estimate of effect. A comprehensive search was performed to identify case-control or cohort studies (from 1990 to 2015) of the aforementioned association. The I (2) statistic was used to examine between-study heterogeneity. Fixed or random effect model was selected based on heterogeneity test among studies. Publication bias was estimated using Egger's regression asymmetry test. A total of 12 published articles with 13 studies were finally included in our meta-analysis. Results showed that the pooled odds ratio (OR) for SLE risk was 1.56 (95% confidence interval (CI) = 1.26-1.95) among current smokers compared with nonsmokers. For ex-smokers versus nonsmokers, the pooled OR for SLE risk was 1.23 (95% CI = 0.93-1.63). Subgroup analysis by geographic location and cumulative meta-analysis were also analyzed. In conclusion, our meta-analysis suggested that smoking increased the risk of SLE. Further studies are needed to confirm this result.

Sleep disorders and increased risk of autoimmune diseases in individuals without sleep apnea

STUDY OBJECTIVES

To explore the association between the non-apnea sleep disorder (NSD) and autoimmune diseases.

DESIGN

Cohort study.

SETTING

Nationwide database research.

PARTICIPANTS

84,996 adult patients with NSD diagnoses recorded in the Taiwan National Health Insurance Research Database between 2000 and 2003, after excluding those with antecedent autoimmune diseases. A comparison cohort of 84,996 participants was formed by age-, gender-, income-, and urbanization-matched controls.

INTERVENTIONS

None.

MEASUREMENTS AND RESULTS

The two cohorts were followed up for occurrence of autoimmune diseases, including rheumatoid arthritis (RA), ankylosing spondylitis (AS), systemic lupus erythematosus (SLE), Sjögren's syndrome (SS), and systemic sclerosis (SSc). A Cox proportional hazards regression model was used for muti-variate adjustment. In patients with NSD, the overall risk for incident autoimmune diseases was significantly higher than in controls (adjusted hazard ratio [HR] = 1.47, 95% confidence interval [CI] = 1.41-1.53). With regard to individual diseases, the risks for SLE, RA, AS and SS among NSD patients were also significantly higher than in controls (HR [95% CI] for SLE, RA, AS, and SS were 1.81 [1.50-2.18], 1.45 [1.36-1.54], 1.53 [1.38-1.70], and 1.51 [1.43-1.60], respectively), whereas the increased risk for SSc did not reach statistical significance (HR: 1.36 [0.82-2.26]).

CONCLUSION

Patients with non-apnea sleep disorder were associated with a higher risk for developing autoimmune diseases.

Modifiable environmental factors in multiple sclerosis

Potential environmental modifiable factors involved in multiple sclerosis (MS) include low adherence to treatment, smoking, obesity, low levels of liposoluble vitamins A and D, high consumption of salt, and a sedentary lifestyle. Chronic tobacco use, obesity, sedentarism and insufficient levels of these vitamins all contribute to maintenance of a proinflammatory state. It is unlikely that there will be noticeable improvement in the inflammatory condition of MS if stopping smoking, reducing weight, exercising, increasing vitamin levels are done in an isolated and erratic manner. Modification of each and every one of these environmental risk factors is likely to be an important approach in the management of MS. The present review presents the arguments for an association between these hazardous modifiable factors and the chronic inflammatory state observed in MS.

Free radicals: properties, sources, targets, and their implication in various diseases

Free radicals and other oxidants have gained importance in the field of biology due to their central role in various physiological conditions as well as their implication in a diverse range of diseases. The free radicals, both the reactive oxygen species (ROS) and reactive nitrogen species (RNS), are derived from both endogenous sources (mitochondria, peroxisomes, endoplasmic reticulum, phagocytic cells etc.) and exogenous sources (pollution, alcohol, tobacco smoke, heavy metals, transition metals, industrial solvents, pesticides, certain drugs like halothane, paracetamol, and radiation). Free radicals can adversely affect various important classes of biological molecules such as nucleic acids, lipids, and proteins, thereby altering the normal redox status leading to increased oxidative stress. The free radicals induced oxidative stress has been reported to be involved in several diseased conditions such as diabetes mellitus, neurodegenerative disorders (Parkinson's disease-PD, Alzheimer's disease-AD and Multiple sclerosis-MS), cardiovascular diseases (atherosclerosis and hypertension), respiratory diseases (asthma), cataract development, rheumatoid arthritis and in various cancers (colorectal, prostate, breast, lung, bladder cancers). This review deals with chemistry, formation and sources, and molecular targets of free radicals and it provides a brief overview on the pathogenesis of various diseased conditions caused by ROS/RNS.

Chinese Systemic Lupus Erythematosus Treatment and Research Group Registry VI: Effect of Cigarette Smoking on the Clinical Phenotype of Chinese Patients with Systemic Lupus Erythematosus

OBJECTIVES

Our study aimed to investigate the effect of cigarette smoking on the clinical phenotype of patients registered in the Chinese Systemic Lupus Erythematosus (SLE) Treatment and Research (CSTAR) group registry database, the first online registry of Chinese patients with SLE.

METHODS

A prospective cross-sectional study of Chinese SLE patients was conducted using the CSTAR. Our case-control analysis was performed on age- and gender-matched subjects to explore the potential effect of cigarette smoking on the clinical manifestation of SLE.

RESULTS

Smokers comprised 8.9% (65/730) of patients, and the ratio of females/males was 19/46. Thirty-nine patients were current smokers, and 26 were ex-smokers. Data showed significant differences between smokers and nonsmokers in the following areas: nephropathy (58.5% vs. 39.2%; p = 0.003), microscopic hematuria (30.8% vs. 19.1%; p = 0.025), proteinuria (53.8% vs. 34.4%; p = 0.002), and SLE Disease Activity Index(DAI) scores (12.38±8.95 vs. 9.83±6.81; p = 0.028). After adjusting for age and gender, significant differences between smokers and nonsmokers were found with photosensitivity (35.9% vs. 18%; p = 0.006), nephropathy (59.4% vs. 39.8%; p = 0.011), and proteinuria (54.7% vs. 35.2%). Although smokers tended to have greater disease severity compared with nonsmokers (SLEDAI scores: 12.58±8.89 vs.10.5±7.09), the difference was not significant (p = 0.081).

CONCLUSIONS

Cigarette smoking triggers the development and exacerbation of SLE, especially with respect to renal involvement. Chinese smokers with SLE should be advised to discontinue cigarette use.

Cigarette smoking, alcohol consumption and risk of systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a complex multisystem autoimmune disease whose pathogenesis is thought to involve both genetic and environmental factors. It is possible that common environmental exposures, such as cigarette smoking and alcohol consumption, might modify risk of disease development in certain individuals. Here we aim to review the epidemiologic evidence related to the association of cigarette smoking, alcohol consumption and the risk of developing SLE. A growing body of evidence suggests that cigarette smoking confers a short-term increased risk of SLE in genetically susceptible individuals. On the other hand, alcohol consumption in moderate doses may have a protective effect against the development of SLE, although this is still debated. We also have reviewed proposed mechanistic explanations underlying the role of cigarette smoking and alcohol consumption in SLE pathogenesis.

Predicting post-vaccination autoimmunity: who might be at risk?

Vaccinations have been used as an essential tool in the fight against infectious diseases, and succeeded in improving public health. However, adverse effects, including autoimmune conditions may occur following vaccinations (autoimmune/inflammatory syndrome induced by adjuvants--ASIA syndrome). It has been postulated that autoimmunity could be triggered or enhanced by the vaccine immunogen contents, as well as by adjuvants, which are used to increase the immune reaction to the immunogen. Fortunately, vaccination-related ASIA is uncommon. Yet, by defining individuals at risk we may further limit the number of individuals developing post-vaccination ASIA. In this perspective we defined four groups of individuals who might be susceptible to develop vaccination-induced ASIA: patients with prior post-vaccination autoimmune phenomena, patients with a medical history of autoimmunity, patients with a history of allergic reactions, and individuals who are prone to develop autoimmunity (having a family history of autoimmune diseases; asymptomatic carriers of autoantibodies; carrying certain genetic profiles, etc.).

The potential role of epigenetic modifications in the heritability of multiple sclerosis

It is now well established that both genetic and environmental factors contribute to and interact in the development of multiple sclerosis (MS). However, the currently described causal genetic variants do not explain the majority of the heritability of MS, resulting in 'missing heritability'. Epigenetic mechanisms, which principally include DNA methylation, histone modifications and microRNA-mediated post-transcriptional gene silencing, may contribute a significant component of this missing heritability. As the development of MS is a dynamic process potentially starting with inflammation, then demyelination, remyelination and neurodegeneration, we have reviewed the dynamic epigenetic changes in these aspects of MS pathogenesis and describe how environmental risk factors may interact with epigenetic changes to manifest in disease.

Digesting the emerging role for the gut microbiome in central nervous system demyelination

The fields of microbiology, immunology, neurology and nutrition are rapidly converging, as advanced sequencing and genomics-based methodologies have enabled the mapping out of the microbial diversity of humans for the first time. Bugs, guts, brains and behavior were once believed to be separate domains of clinical practice and research; however, recent observations in our understanding of the microbiome indicate that the boundaries between domains are becoming permeable. This permeability is multidirectional: Biological systems are operating simultaneously in a vastly complex and interconnected web. Understanding the microbiome-gut-brain axis will entail fleshing out the mechanisms by which transduction across each domain occurs, allowing us ultimately to appreciate the role of commensal organisms in shaping and modulating host immunity. This article will highlight animal and human research to date, as well as highlight directions for future research. We speculate that the gut microbiome is potentially the premier environmental risk factor mediating inflammatory central nervous system demyelination, in particular multiple sclerosis.

Role of "Western diet" in inflammatory autoimmune diseases

Developed societies, although having successfully reduced the burden of infectious disease, constitute an environment where metabolic, cardiovascular, and autoimmune diseases thrive. Living in westernized countries has not fundamentally changed the genetic basis on which these diseases emerge, but has strong impact on lifestyle and pathogen exposure. In particular, nutritional patterns collectively termed the "Western diet", including high-fat and cholesterol, high-protein, high-sugar, and excess salt intake, as well as frequent consumption of processed and 'fast foods', promote obesity, metabolic syndrome, and cardiovascular disease. These factors have also gained high interest as possible promoters of autoimmune diseases. Underlying metabolic and immunologic mechanisms are currently being intensively explored. This review discusses the current knowledge relative to the association of "Western diet" with autoimmunity, and highlights the role of T cells as central players linking dietary influences to autoimmune pathology.

Smoking reduces the risk of hypothyroidism and increases the risk of hyperthyroidism: evidence from 450,842 mothers giving birth in Denmark

OBJECTIVE

Smoking may influence on the occurrence of thyroid disease, but studies have led to inconsistent results. In Denmark, information on maternal smoking during pregnancy is registered by midwives, and we investigated the association between maternal smoking as reported during pregnancy and the subsequent maternal risk of having hyper- or hypothyroidism diagnosed.

DESIGN

Population-based cohort study.

PARTICIPANTS

Using Danish nationwide registers, we identified mothers giving birth in Denmark, 1996-2008, and studied their first pregnancy in the study period.

MEASUREMENTS

Information on maternal smoking during the pregnancy and maternal diagnosis of hyper- or hypothyroidism was obtained from the Danish National Hospital Register (DNHR) and prescription of thyroid medication from the Danish National Prescription Register (DNPR). Cox proportional hazards model was used to estimate hazard ratio (HR) with 95% confidence interval (95% CI) for onset of maternal hyper- or hypothyroidism after birth of the child in multivariate analyses adjusting for potential confounders.

RESULTS

Among mothers included (n = 450 842), altogether 89,022 (19·7%) reported that they were smokers during the first pregnancy in the study period, and 8905 (2·0%) developed hyper (n = 3389)- or hypothyroidism (n = 5516) after birth of the child. Maternal smoking was associated with a subsequent decreased risk of developing hypothyroidism (adjusted HR 0·75 (95% CI 0·70-0·81)) and an increased risk of hyperthyroidism (1·38 (1·27-1·49)).

CONCLUSIONS

Danish nationwide registration of maternal smoking during pregnancy adds further evidence to an association between smoking and thyroid dysfunction; smoking reduced the risk of hypothyroidism and increased the risk of hyperthyroidism.

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.

Management of cardiovascular risk in patients with rheumatoid arthritis: evidence and expert opinion

The risk of cardiovascular morbidity and mortality is increased in rheumatoid arthritis. The classical cardiovascular risk factors, including smoking, hypertension, dyslipidaemia, insulin resistance and diabetes mellitus, obesity and physical inactivity do not appear to explain the excess cardiovascular risk in rheumatoid arthritis, although they do contribute, albeit in a different way or to a lesser extent, to rheumatoid arthritis in comparison with the general population. A very important link between rheumatoid arthritis and cardiovascular disease is inflammation as it plays a key role in all stages of atherosclerosis: from endothelial dysfunction to plaque rupture and thrombosis. It also has an influence on and accentuates some traditional cardiovascular risk factors, such as dyslipidaemia, obesity and insulin resistance. To date, the exact pathophysiologic mechanism by which this relation between cardiovascular disease and rheumatoid arthritis can be explained is not completely clear. Cardiovascular risk management in rheumatoid arthritis is mandatory. Unfortunately, the way this should be done remains a point of discussion. In this review issues regarding cardiovascular risk in rheumatoid arthritis and its management will be addressed, according to evidence presented in the latest studies and our own experience-based opinion.

Questionnaire based assessment of risk factors for primary biliary cirrhosis

BACKGROUND

Primary biliary cirrhosis is a cholestatic liver disease characterized by immune-mediated destruction of bile ducts. Its pathogenesis is largely unknown, although complex interactions between environment and genetic predisposition are proposed.

AIMS

Identify disease risk factors using a detailed patient questionnaire and compare study findings to 3 published reports.

METHODS

Questionnaire data were prospectively collected from 522 cases and 616 controls of the Mayo Clinic Primary Biliary Cirrhosis Genetic Epidemiology Registry. Case and control responses were compared using logistic regression, adjusting for recruitment age, sex, and education level.

RESULTS

Cases reported ever regularly smoking cigarettes more frequently than controls (P < 0.001). History of urinary tract infection was similar between groups; however, cases reported multiple urinary tract infections more commonly than controls (P < 0.001). Frequency of other autoimmune disease was higher in cases than controls (P < 0.001). As well, prevalence of primary biliary cirrhosis among first-degree relatives was higher in case families than control families (P < 0.001).

CONCLUSIONS

Our study confirms prior reported risk factors associated with disease risk. Given the potential importance of gene and environment interactions, further examination of environmental risk factors considering genetic background may provide new insight into primary biliary cirrhosis pathogenesis.

Sex-specific environmental influences on the development of autoimmune diseases

Sex differences in autoimmune diseases are evolutionarily tied to the fact that the female immune system is confronted with intense alterations during menstrual cycles, pregnancy and childbirth. These events may be associated with breaches in the mucosal epithelial layers that are shielding us from environmental factors. Associations between environmental agents and autoimmune diseases have been described extensively in prior studies. Little evidence, however, exists for sex-specific environmental effects on autoimmune diseases. In this review, we summarize studies involving this often-neglected aspect. We give examples of environmental factors that may influence the sex bias in autoimmunity. We conclude that most studies do not give insight into sex-specific environmental effects due to the influence of gender-selective social, occupational or other exposures. Prospective studies are needed in order to determine true sex-biased environmental influences. Finally, humanized murine models might aid in better understanding the mechanisms involved in sex-specific environmental effects on autoimmune diseases.

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.

The role of autoimmunity in obliterative bronchiolitis after lung transplantation

First performed in the 1960s with long-term successes achieved in the 1980s, lung transplantation remains the only definitive treatment option for end-stage lung disease. Chronic lung rejection, pathologically classified as obliterative bronchiolitis (OB) with its clinical correlate referred to as bronchiolitis obliterans syndrome, is the limiting factor than keeps 5-yr survival rates for lung transplant significantly worse than for other solid organ transplants. Initially, OB was largely attributed to immune responses to donor antigens, alloimmunity. However, more recent work has demonstrated the role of autoimmunity in the process of lung transplant rejection. IL-17 and autoantigens such as collagen type V and K-α1 tubulin have been implicated in the development of chronic rejection. Ultimately, this translational review discusses the role that autoimmunity plays in the development of OB and lung transplant rejection and then discusses options for therapeutic intervention.