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

Environmental risk factors for multiple sclerosis: a review with a focus on molecular mechanisms

Multiple sclerosis (MS) is a chronic disabling disease of the central nervous system commonly affecting young adults. Pathologically, there are patches of inflammation (plaques) with demyelination of axons and oligodendrocyte loss. There is a global latitude gradient in MS prevalence, and incidence of MS is increasing (particularly in females). These changes suggest a major role for environmental factors in causation of disease. We have reviewed the evidence and potential mechanisms of action for three exposures: vitamin D, Epstein Barr virus and cigarette smoking. Recent advances supporting gene-environment interactions are reviewed. Further research is needed to establish mechanisms of causality in humans and to explore preventative strategies.

Smoking and early pregnancy thyroid hormone and anti-thyroid antibody levels in euthyroid mothers of the Northern Finland Birth Cohort 1986

BACKGROUND

Smokers in the general population have lower thyrotropin (TSH) and higher free triiodothyronine (fT3) and free thyroxine (fT4) concentrations, but the results in pregnant population vary from no effect to a decrease in TSH and fT4 concentrations and an increase in fT3 levels. Our objective was to further evaluate the question of whether there is an association between smoking, before and during pregnancy, with maternal thyroid function during pregnancy and with the risk for subsequent hypothyroidism.

METHODS

Our study population was a prospective population-based cohort (N=9362), the Northern Finland Birth Cohort 1986, with extensive data throughout gestation. The mothers underwent serum sampling in early pregnancy. The samples were assayed for TSH, fT3, fT4, thyroid-peroxidase antibodies (TPO-Ab), and thyroglobulin antibodies (TG-Abs) (n=5805). Mothers with thyroid dysfunction diagnosed before or during pregnancy were excluded, leaving 4837 euthyroid mothers. The smoking status of mothers and fathers were requested by questionnaires during pregnancy. Subsequent maternal morbidity relating to hypothyroidism 20 years after the index pregnancy was evaluated using national registers.

RESULTS

Euthyroid mothers who smoked before, or continued smoking during first trimester of pregnancy, had higher serum fT3 (p<0.001) and lower fT4 (p=0.023) concentrations than nonsmokers. Smoking in the second trimester was associated with higher fT3 (p<0.001) concentrations, but no difference in fT4 concentrations compared with nonsmokers. TG-Abs were less common among smoking than nonsmoking mothers (2.5% vs. 4.7%, p<0.001), but the prevalence of TPO-Ab was similar. Paternal smoking had no independent effect on maternal early pregnancy thyroid hormone or antibody concentrations. The risk of subsequent maternal hypothyroidism after follow-up of 20 years was similar among prepregnancy smokers and nonsmokers.

CONCLUSIONS

In euthyroid women, smoking during pregnancy was associated with higher fT3 levels and lower fT4 levels; possibly reflecting smoking-induced changes in peripheral metabolism of thyroid hormones. No differences were found in TSH concentrations between smokers and nonsmokers. Our results differ from those of the general population, which usually have shown smoking-induced thyroidal stimulation. This is possibly due to pregnancy-induced changes in thyroid function. Decreases in fT4 levels among smokers might predispose to hypothyroidism or hypothyroxinemia during pregnancy. Despite these changes in thyroid function, smoking did not increase the woman's risk of subsequent hypothyroidism.

Autoimmunity and environment: am I at risk?

The complex interplay between environmental factors and genetic susceptibility plays an essential role in disease pathogenesis. This is especially true for autoimmunity, where clinical reports, genomic and epidemiological studies, as well as animal models have identified several environmental and genetic risk factors associated with autoimmune disease. The complexity of this relationship is demonstrated by the vast array of environmental factors that have now been implicated in the induction, and possibly the maintenance of autoimmune disease. The multitude of environmental factors implicated includes both infectious and non-infectious agents. Here, we review one specific autoimmune disease, primary biliary cirrhosis (PBC), as a model for environmental risk factors acting in concert with genetic susceptibility in the disease pathogenesis. PBC is an ideal model, as both infectious and non-infectious environmental agents have been identified as risk factors, and their study provides clues for unravelling the pathogenesis of the disease.

Low-dose smoking resumption in ex-smokers with refractory ulcerative colitis

BACKGROUND AND AIM

Ulcerative colitis (UC) is primarily a disease of non-smokers. Ex-smokers may have a more refractory disease course and anecdotal evidence in non-controlled clinical trials have suggested that smoking resumption, or the administration of nicotine, may ameliorate signs and symptoms of UC in ex-smokers. We report outcomes of ex-smokers with refractory UC who resumed low-dose cigarette smoking.

METHODS

17 ex-smokers with refractory UC were identified. Clinical remission was defined as a disease activity index score of 0.

RESULTS

Two out of 17 patients refused the recommendation to resume smoking. Of the 15 patients who resumed smoking, the mean daily number of cigarettes was 8.6. Fourteen out of those 15 patients who resumed smoking were able to maintain prolonged clinical remission off steroids. One out of the 15 patients failed to improve and required oral steroids. Another patient was compelled to quit smoking since he became addicted. His disease flared after maintaining a prolonged remission of 3 years and he eventually underwent surgery. Three out of these 15 patients switched from cigarettes smoking to nicotine compounds and continued to maintain remission.

CONCLUSION

Resumption of low dose smoking in a selected group of ex-smokers with refractory UC may ameliorate signs and symptoms. Quality of life, medication side effects, and smoking risk factors should all be considered and discussed with patients. Smokers should be meticulously followed for compliance with "low-dose" regimen and all associated smoking risks.

Can supplementation with vitamin D reduce the risk or modify the course of autoimmune diseases? A systematic review of the literature

OBJECTIVE

To evaluate whether vitamin D levels are related to the risk of developing autoimmune diseases and whether supplementation with vitamin D can modify the course of the diseases.

METHODS

We reviewed the most relevant papers published from January 1973 to October 2011, using Medline and EMBASE and the search terms "vitamin D"; "autoimmune disease"; "autoimmunity"; "rheumatoid arthritis"; "systemic lupus erythematosus"; "scleroderma"; "systemic sclerosis"; "type 1 diabetes"; "multiple sclerosis"; and "undifferentiated connective tissue disease". We selected studies on the environmental, genetic and epidemiologic association of vitamin D with autoimmune diseases. Using the strategy described, we identified 1268 articles. 331 articles were eliminated on the basis of the title and another 703 on the basis of the abstract, since they were considered irrelevant for the purposes of the study. Full-text examination was performed on the remaining 234 studies, and a further 15 studies were excluded from the review, since the results had been confirmed or superseded by more recent research. Finally, a systematic review was conducted on 219 articles concerning cross-sectional data on: vitamin D levels and autoimmune diseases; interventional data on vitamin D supplementation in autoimmune diseases; prospective data linking vitamin D level or intake to autoimmune disease risk.

RESULTS

Physiopathology studies confirm that hypovitaminosis D, in genetically predisposed subjects, can impair self tolerance by compromising the regulation of dendritic cells, of regulatory T-lymphocytes and of Th1 cells. Cross-sectional studies show that levels of vitamin D <30 ng/mL are present in a significant percentage, not only in patients with autoimmune disease, but also in healthy subjects (30-77%), and link profound deficiency (<10 ng/mL) with aggravation of symptomatology, while genetic studies associate polymorphism of vitamin D receptors to various autoimmune diseases. Among experimental studies on humans, only those on type-1 diabetes prove that the risks are significantly reduced in infants treated with vitamin D after the 7th month (OR 0.71, 95% CI, 0.60 to 0.84) and that a dose-response effect exists.

CONCLUSIONS

Basic, genetic, and epidemiological studies indicate a potential role of vitamin D in the prevention of autoimmune diseases, but randomized and controlled trials are necessary to establish the clinical efficacy of vitamin D supplementation in ill or at-risk subjects.

Risk of asthma and autoimmune diseases and related conditions in patients hospitalized for obesity

BACKGROUND

Although there are putative mechanistic links between obesity and autoimmune diseases, obesity is not considered a risk factor for most autoimmune diseases.

METHODS

Using the nation-wide Hospital Discharge Register we defined a cohort of 29,665 patients hospitalized for obesity since year 1964. The patients were followed for hospitalization for any of 34 autoimmune or related conditions through year 2007. Standardized incidence ratios (SIRs) were calculated for autoimmune diseases in obese individuals compared to those who had not been hospitalized for obesity.

RESULTS

Among 22 immune diseases diagnosed after hospitalization for obesity and in at least 5 patients, the overall SIR was 2.05. Of the individual diseases studied, the risk of 16 was significantly increased; none displayed a decreased risk. Psoriasis (4.54) and Behçet's disease (4.49) exhibited the highest risks, followed by Hashimoto's disease/hypothyroidism (4.12) and asthma (3.39). Small but significant increases in SIRs were also noted for the common autoimmune diseases Graves's disease/hyperthyroidism (1.28) and rheumatoid arthritis (1.37).

CONCLUSIONS

The present population of obese individuals, subsequently diagnosed with a number of autoimmune diseases and related conditions, was hospitalized at a relatively young age. Further studies are needed to describe the morbidity in the obese population at large.

Hair dyes as a risk for autoimmunity: from systemic lupus erythematosus to primary biliary cirrhosis

Environmental and genetic factors appear to be involved in the pathogenesis of primary biliary cirrhosis (PBC), a chronic cholestatic liver disease characterized by immune-mediated destruction of the small and medium sized intrahepatic bile ducts. Environmental factors include exposure to various infectious, xenobiotic and chemical compounds. These exposures may occur occupationally, through water or air contamination, pharmacological administration or by elective exposure, to name a few. Hair dyes are compounds that have been implicated in the development of several autoimmune diseases, including systemic lupus erythematosus (SLE) and PBC. So far, only epidemiological studies have addressed the role of hair dyes in PBC, with limited results. Hair dyes in SLE have been examined, and have recently demonstrated an association, both epidemiologically and immunologically. This follows a series of negative studies, which may not have taken into account several features of hair dye use. This review will examine the literature surrounding hair dye use and SLE, and compare this to data surrounding PBC. Treating physicians should be prepared for questions surrounding the need to take precautions against repeated hair dye use and this topic is discussed further.

Smoking as an independent risk factor of liver fibrosis in primary biliary cirrhosis

BACKGROUND & AIMS

Smoking has been identified as a potential predisposition factor for primary biliary cirrhosis (PBC). However, it remains unclear whether it is associated with more active and severe disease. Our aim was to assess the relationships between smoking and the severity of the elementary histological lesions, as well as the biochemical and immunological features of PBC.

METHODS

Smoking history data were collected from 223 PBC patients using a standardized questionnaire. Histological data were available in 164 patients at presentation. Liver fibrosis and histological inflammatory activity were semi-quantified according to a METAVIR-based classification system. Odds ratios (OR) were assessed using a logistic regression analysis.

RESULTS

Smoking history prior to diagnosis was reported in 58 patients (26%). Twenty-five patients (11%) were active smokers at diagnosis. Male gender (OR, 4.5), alcohol intake >20 g/d (OR, 4.2), and F3-F4 fibrosis stage (OR, 2.7), but not inflammatory grade, bile duct changes, biochemical or immunological features, were associated with smoking history. Smoking intensity was significantly higher in patients with F3-F4 stage (8.1±14.2 pack-years vs. 3.0±7.0 pack-years; p=0.01). Adjusted logistic regression identified smoking history and smoking intensity as independent risk factors of advanced fibrosis. Each pack-year of increase in smoking intensity was associated with a 5.0% (95% CI, 1.3-8.7%) increased likelihood of advanced fibrosis.

CONCLUSIONS

Smoking increases, in a dose-dependent fashion, the risk of liver fibrosis in PBC without apparent increase in the histological inflammatory activity, bile duct lesions, biochemical, and immunological features of the disease. PBC patients should be strongly encouraged not to smoke.

Gender differences in autoimmunity associated with exposure to environmental factors

Autoimmunity is thought to result from a combination of genetics, environmental triggers, and stochastic events. Gender is also a significant risk factor with many diseases exhibiting a female bias. Although the role of environmental triggers, especially medications, in eliciting autoimmunity is well established less is known about the interplay between gender, the environment and autoimmunity. This review examines the contribution of gender in autoimmunity induced by selected chemical, physical and biological agents in humans and animal models. Epidemiological studies reveal that environmental factors can be associated with a gender bias in human autoimmunity. However many studies show that the increased risk of autoimmunity is often influenced by occupational exposure or other gender biased activities. Animal studies, although often prejudiced by the exclusive use of female animals, reveal that gender bias can be strain specific suggesting an interaction between sex chromosome complement and background genes. This observation has important implications because it argues that within a gender biased disease there may be individuals in which gender does not contribute to autoimmunity. Exposure to environmental factors, which encompasses everything around us, adds an additional layer of complexity. Understanding how the environment influences the relationship between sex chromosome complement and innate and adaptive immune responses will be essential in determining the role of gender in environmentally-induced autoimmunity.

Maternal allergy acts synergistically with cigarette smoke exposure during pregnancy to induce hepatic fibrosis in adult male offspring

Maternal environmental exposures during pregnancy are known to affect disease onset in adult offspring. For example, maternal asthma exacerbations during pregnancy can worsen adult asthma in the offspring. Cigarette smoking during pregnancy is associated with future onset of cardiovascular disease, obesity and diabetes. However, little is known about the effect of maternal environmental exposures on offspring susceptibility to liver disease. This pilot study examined the long-term effect of maternal allergen challenge and/or cigarette smoking during pregnancy on hepatic inflammation and fibrosis in adult mouse offspring. Ovalbumin (OVA) or phosphate-buffered saline (PBS)-sensitized/challenged CD-1 dams were exposed to mainstream cigarette smoke (MCS) or filtered air from gestational day 4 until parturition. Eight weeks postnatally, offspring were sacrificed for comparison of hepatic histology and mRNA expression. Adult male offspring of OVA-sensitized/challenged dams exposed to MCS (OSM) displayed significantly increased liver fibrosis (9.2% collagen content vs. <4% for all other treatment groups). These mice also had 1.8-fold greater collagen 1A1 mRNA levels. From the results here, we concluded that maternal allergen challenge in combination with cigarette smoke exposure during pregnancy may be an important risk factor for liver disease in adult male offspring.

Citrullination of autoantigens: upstream of TNFα in the pathogenesis of rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic autoimmune disease characterised by synovial inflammation and destruction of joints. Over 20 years ago, tumour necrosis factor alpha (TNFα) was identified as a key player in a cytokine network, whose multifunctional effects could account for both the inflammation and destruction in RA. The remarkable efficacy of TNF inhibitors in the treatment of RA has resulted in extensive research addressing the regulation of TNFα production responsible for this excessive production. The discovery of autoimmunity to citrullinated protein/peptide antigens (ACPA) has led the concept that ACPA may be the essential link between disease susceptibility factors and the production of TNFα, which ultimately accounts for the disease phenotype. In this review we will consider (1) the mechanisms of citrullination, both physiological and pathological, (2) how known genetic and environmental factors could drive this peculiar form of autoimmunity and (3) how the immune response could lead to excessive production of TNFα by the synovial cells and ultimately to the disease phenotype (Fig. 1).

Systemic lupus erythematosus and cardiac risk factors: medical record documentation and patient adherence

This study explores patients' knowledge of cardiac risk factors (CRFs), analyses how information and advice about CRFs are documented in clinical practice, and assesses patient adherence to received instructions to decrease CRFs. Systemic lupus erythematosus (SLE) patients with ≥ 4 ACR criteria participated through completing a validated cardiovascular health questionnaire (CHQ). Kappa statistics were used to compare medical records with the self-reported CHQ (agreement) and to evaluate adherence. Two hundred and eleven (72%) of the known patients with SLE participated. The mean age of the patients was 55 years. More than 70% of the SLE patients considered hypertension, obesity, smoking and hypercholesterolaemia to be very important CRFs. The agreement between medical record documentation and patients' reports was moderate for hypertension, overweight and hypercholesterolaemia (kappa 0.42-0.60) but substantial for diabetes (kappa 0.66). Patients' self-reported adherence to advice they had received regarding medication was substantial to perfect (kappa 0.65-1.0). For lifestyle changes in patients with hypertension and overweight, adherence was only fair to moderate (kappa 0.13-0.47). Swedish SLE patients' awareness of traditional CRFs was good in this study. However, the agreement between patients' self-reports and medical record documentation of CRF profiles, and patients' adherence to medical advice to CRF profiles, could be improved.

Smoking and increased risk of multiple sclerosis: parallel trends in the sex ratio reinforce the evidence

PURPOSE

Smoking behavior in industrialized nations has changed markedly over the second half of the 20th century, with diverging patterns in male and female smoking rates. We examined whether the female/male incidence of multiple sclerosis (MS) changed concomitantly with smoking, as would be expected if smoking truly increased MS risk.

METHODS

We identified relevant studies reporting male and female age-specific incidence of MS throughout the world using within-country birth cohorts as units of observation. We then correlated the male/female ratio of MS incidence in each birth cohort with the corresponding male/female ratios in smoking behavior obtained from national statistics. We also examined in depth the within-country trends of smoking and MS in Canada and Denmark, two populations in which statistics on MS are readily available.

RESULTS

We show that, on the natural log scale, the gender ratio of MS is correlated with the gender ratio of smoking (r = 0.16; 95% confidence interval [CI]: 0.06, 0.26; p = 0.002). Additionally, we estimated an overall incidence rate ratio of 1.50 (95% CI: 1.17, 2.01) of MS for ever-smokers as compared with never-smokers. The trend in the gender ratio of smoking, however, is driven by a decline in smoking among men, rather than by an increase in women as observed for MS incidence.

CONCLUSIONS

Our results are consistent with the hypothesis that smoking increases the risk of MS and explains in part the divergence in MS incidence rates in men and women. Some other factor, however, must account for the increasing MS incidence among women.

Small-cell lung cancer-associated autoantibodies: potential applications to cancer diagnosis, early detection, and therapy

Small-cell lung cancer (SCLC) is the most aggressive lung cancer subtype and lacks effective early detection methods and therapies. A number of rare paraneoplastic neurologic autoimmune diseases are strongly associated with SCLC. Most patients with such paraneoplastic syndromes harbor high titers of antibodies against neuronal proteins that are abnormally expressed in SCLC tumors. These autoantibodies may cross-react with the nervous system, possibly contributing to autoimmune disease development. Importantly, similar antibodies are present in many SCLC patients without autoimmune disease, albeit at lower titers. The timing of autoantibody development relative to cancer and the nature of the immune trigger remain to be elucidated. Here we review what is currently known about SCLC-associated autoantibodies, and describe a recently developed mouse model system of SCLC that appears to lend itself well to the study of the SCLC-associated immune response. We also discuss potential clinical applications for these autoantibodies, such as SCLC diagnosis, early detection, and therapy.

Cigarette smoking in primary Sjögren's syndrome: positive association only with ANA positivity

Smoking is well known to contribute to the pathogenesis and severity of some systemic autoimmune rheumatic diseases and especially to the production of certain autoantibodies. Primary Sjögren's syndrome (pSS) is an autoimmune disease, affecting primarily the exocrine glands. It may also cause extraglandular involvement in some cases. In this study, we aimed to determine the frequency of smoking habits in our cohort of pSS patients and to investigate whether the frequencies of autoantibody positivity and extraglandular involvement were significantly different between patients with and without smoking. In this cross-sectional study, 207 patients with pSS (F/M 203/4), fulfilling the United States-European Consensus Criteria, and 602 healthy controls (F/M 534/68) were included. Patients and controls were classified into five groups: never smokers, current smokers, former smokers; ever smokers, and passive smokers. The χ(2) and Kruskal-Wallis tests were used for statistical analysis; a p value of less than 0.05 was accepted as statistically significant. While the frequency of current smokers was significantly lower in the pSS group compared with the healthy controls (11.6 vs 22.3%), the frequencies of former smokers (30.4 vs 11.8%), ever smokers (42.0 vs 34.1%), and passive smokers (47.3 vs 37.5%) were significantly higher in the pSS group compared with the healthy controls. In pSS patients, only antinuclear antibody (ANA) positivity was significantly associated with smoking habits, while there was no significant association with other autoantibodies or with the presence of extraglandular involvement. We found that in pSS patients smoking was significantly associated only with ANA positivity. Unlike the deleterious effects of smoking upon disease severity and anti-cyclic citrullinated protein (CCP) antibody production in rheumatoid arthritis, we could not find any association of smoking with extraglandular involvement and/or anti-Ro/anti-La antibody positivity in pSS. These results are indeed in line with the limited number of previous studies reported in the literature. Further studies with higher numbers of pSS patients are required to confirm the seemingly negative association of smoking with pSS.

The ocular surface in thyroid diseases

PURPOSE OF REVIEW

The purpose of the present review is to describe recent insights into the pathomechanism of ocular surface impairment in the course of thyroid dysfunctions. The review focuses in particular on Graves' ophthalmopathy as the majority of the literature is published on this topic.

RECENT FINDINGS

Mechanical factors were thought, until now, to be the indirect causes of ocular surface function failure. In particular, eyeglobe bulging and upper eyelid retraction with consequent eyelid fissure width increase were mainly considered responsible for increased exposed area and ocular surface impairment. Recent evidence demonstrated that ocular surface tissues are direct targets for autoantibodies in either hypothyroid or hyperthyroid states. A set of tear protein biomarkers were identified and shown to have high diagnostic performance.

SUMMARY

New horizons can be displayed on the basis of these new findings, in particular, as referred earlier, Graves' ophthalmopathy diagnosis. A detailed slit-lamp examination and a careful medical history by validated questionnaires in patients with ocular surface discomfort symptoms are now recommended to investigate early manifestations of an underlying thyroid dysfunction. Ocular surface signs should also be included in professional guidelines. Autoantibody assays in tears and proteomic analysis of tear protein expression could be important further steps in early diagnosis and posttherapy control of thyroid dysfunction.

Cigarette smoke inhibits recruitment of bone-marrow-derived stem cells to the uterus

Cigarette smoking leads to female infertility and a decreased incidence of endometriosis. Bone marrow derived stem cells are recruited to uterine endometrium and endometriosis. The effect of cigarette smoking on stem cell recruitment to any organ is uncharacterized. We hypothesized that bone marrow-derived mesenchymal stem cell recruitment to the uterus and differentiation would be diminished by cigarette smoke. We used human mesenchymal stem cells (hMSC) in vitro and a mouse model of cigarette smoke exposure. After myeloablation female C57BL/6J received bone marrow cells from males. Mice were exposed to room air or smoke from unfiltered cigarettes. Immunofluorescence and Y-FISH was performed on uterine sections. In vitro hMSCs were treated with 8-Br-cAMP to induce endometrial cell differentiation with or without cigarette smoke extract (CSE) and decidualization assessed morphologically and by prolactin expression. After 4 weeks the total number of Y-chromosome cells in the uterus was reduced by 68% in the smoke exposed mice. Both leukocytes and bone marrow derived endometrial cells were reduced by 60% and 73%, respectively. Differentiation of bone marrow derived cell to endometrial epithelial cells was reduced by 84%. hMSC treated with CSE failed to show cytological characteristics of decidualization. mRNA levels of the decidualization marker prolactin were decreased by 90% in CSE treated cells. Smoking inhibits both recruitment of bone marrow derived stem cells to uterus and stem cell differentiation. Inhibition of stem cells recruitment may be a general mechanism by which smoking leads to long term organ damage through inability to repair or regenerate multiple tissues.

Smokers with multiple sclerosis are more likely to report comorbid autoimmune diseases

BACKGROUND/AIMS

Smoking is a risk factor for multiple sclerosis (MS) and autoimmune disease, and might explain an increased risk of comorbid autoimmune disease (CAD) in MS. We compared the risk of CAD in smokers and nonsmokers with MS.

METHODS

Participants enrolled in the North American Research Committee on Multiple Sclerosis Registry reported their smoking status, the presence of CAD and the year of diagnosis. We used multivariable logistic regression to determine the independent association between smoking and CAD. We also compared the risk of developing a CAD in current smokers versus never-smokers who did not report any CAD at MS onset, using a proportional hazards model.

RESULTS

Among 8,875 participants reporting comorbidities and smoking status, 1,649 (18.5%) reported a CAD. In a multivariable logistic model, ever-smokers had increased odds of reporting a CAD (odds ratio: 1.22; 95% CI: 1.08-1.38). Among the 7,830 participants without a CAD at onset of MS who reported their smoking status, including the age at which they started smoking, 3,035 (36.8%) currently smoked, while 3,805 (48.6%) never smoked. After adjustment, smokers had an increased risk of developing any autoimmune disease (hazard ratio: 1.23; 95% CI: 1.08-1.41) after MS onset.

CONCLUSION

Smoking is associated with an increased risk of CAD in MS.

Inflammation: good or bad for ADHD?

Attention deficit hyperactivity disorder (ADHD) is characterised by the typical behavioural core symptoms of inattentiveness, hyperactivity and impulsiveness. ADHD is a usually chronic health conditions, mostly diagnosed in childhood, creating a significant challenge for youth, their families and professionals who treat it. This disorder requires long-term treatments, including psychotherapeutic and pharmacological interventions, which in some cases may lead to adverse effects. Understanding the mechanism by which ADHD risk factors affect the biochemical processes in the human brain and consequentially the behaviour will help to identify novel targets for the development of therapeutics with less adverse results and better efficacy including higher responder rates. Although inflammatory responses in the brain have been recognised for years as critical in neurodegeneration and behaviour in a number of neurological and psychiatric disorders, their role for the development, treatment and prevention of ADHD has been so far largely overlooked, although historically, ADHD symptoms were initially observed in patients who survived an ONJ infection, i.e. inflammation. In this review, we discuss the interrelationship between different ADHD risk factors and inflammation with respect to the triggered molecular mechanisms and the contribution they are likely to have to this disorder. This paper provides a rationale for future studies on ADHD with an intent to inspiring the development of new agents for a more efficient management of this disorder.

Does vitamin D affect risk of developing autoimmune disease?: a systematic review

OBJECTIVES

We evaluated the epidemiologic evidence that vitamin D may be related to human autoimmune disease risk.

METHODS

PubMed, limited to English from inception through April 2010, was searched using keywords: "vitamin D," "autoimmune," and autoimmune disease names. We summarized in vitro, animal, and genetic association studies of vitamin D in autoimmune disease pathogenesis. We sorted epidemiologic studies by design and disease and performed a systematic review of (a) cross-sectional data concerning vitamin D level and autoimmune disease; (b) interventional data on vitamin D supplementation in autoimmune diseases; and (c) prospective data linking vitamin D level or intake to autoimmune disease risk.

RESULTS

Vitamin D has effects on innate and acquired immune systems, and vitamin D receptor polymorphisms have been associated with various autoimmune diseases. In experimental animal models, vitamin D supplementation can prevent or forestall autoimmune disease. Of 1446 studies identified and screened, 76 studies examined vitamin D levels in autoimmune disease patients, particularly with active disease, and compared with controls. Nineteen observational or interventional studies assessed the effect of vitamin D supplementation as therapy for various autoimmune diseases (excluding psoriasis and vitiligo) with a range of study approaches and results. The few prospective human studies performed conflict as to whether vitamin D level or intake is associated with autoimmune disease risk. No interventional trials have investigated whether vitamin D affects human autoimmune disease risk.

CONCLUSIONS

Cross-sectional data point to a potential role of vitamin D in autoimmune disease prevention, but prospective interventional evidence in humans is still lacking.

The effect of smoking on the symptoms and progression of multiple sclerosis: a review

Multiple sclerosis (MS) is a chronic inflammatory neurodegenerative disorder of the central nervous system with characteristic demyelinating lesions and axonal loss. MS accounts for the most common cause of neurological disability in young adults in the Western world. The clinical manifestations and the course of MS are highly variable. The early stage of the disease is usually characterized by attacks of neurological dysfunction with complete or incomplete recovery, however, with time disability accumulates in many patients. MS is believed to result from an interplay between susceptibility genes and environmental factors, one of which is smoking. Smoking, a worldwide epidemic, can be regarded as an important risk factor for MS particularly because of its modifiable nature in the quest to prevent or temper the disease course in MS as well as providing possible insights into MS pathogenesis. There are also reports that smoking may influence the symptoms and disease progression in patients with MS. The purpose of this article is to review the effects of smoking on MS symptoms and progression. We conclude that (1) although there are some early reports on worsening of MS symptoms by smoking, the existing evidence is insufficient to thoroughly assess the effects of smoking on the myriad of MS symptoms and (2) smoking seems to adversely influence disease progression in MS patients. We also discuss the potential biological mechanisms linking smoking and MS.

Adverse effects of smoking on patients with ocular inflammation

BACKGROUND

To evaluate how smoking affects the time to disease quiescence and time to disease recurrence in patients with ocular inflammation.

METHODS

A retrospective cohort study of patients with ocular inflammation who were followed longitudinally and had smoking information available in the Systemic Immunosuppressive Therapy for Eye Diseases Cohort Study database.

RESULTS

Among 2676 patients with active ocular inflammation, smokers were more likely to have bilateral ocular disease and poorer visual acuity on presentation compared with non-smokers and previous smokers. In a multivariate analysis, there was no statistically significant difference in the time to disease quiescence between groups. However, the median time to recurrence of ocular inflammation was statistically significantly longer for non-smokers (9.4 months) and for previous smokers (10.7 months) than for current smokers (7.8 months) (p=0.02). The RR of ocular inflammation recurrence was higher for smokers than for non-smokers (adjusted HR=1.19, 95% CI 1.03 to 1.37) and tended towards significance in previous smokers (adjusted HR=1.11, 95% CI 0.93 to 1.35).

CONCLUSIONS

Smoking was associated with an increased likelihood of bilateral ocular inflammation and reduced vision upon presentation, and an increased risk of recurrence compared with not smoking. These results suggest that patients with ocular inflammation should be counselled to stop smoking as part of routine management.

Lung myeloid dendritic cells coordinately induce TH1 and TH17 responses in human emphysema

Exposure to tobacco smoke activates innate and adaptive immune responses that in long-term smokers have been linked to diseases of the lungs, cardiovascular system, joints, and other organs. The destruction of lung tissue that underlies smoking-induced emphysema has been associated with T helper 1 cells that recognize the matrix protein elastin. Factors that result in the development of such autoreactive T cells in smokers remain unknown but are crucial for further understanding the pathogenesis of systemic inflammatory diseases in smokers. Here, we show that lung myeloid dendritic cells were sufficient to induce T helper 1 and T helper 17 responses in CD4 T cells. T helper 1 and 17 cells are invariably present in lungs from patients with emphysema but not in lungs from normal individuals. Interleukin-17A, a canonical T helper 17 cytokine, enhanced secretion of CCL20, a chemoattractant for dendritic cells, and matrix metalloproteinase 12, a potent elastolytic proteinase, from lung macrophages. Thus, although diverse lung factors potentially contribute to T helper effector differentiation in vivo, lung myeloid dendritic cells direct the generation of pathogenic T cells and support a feedback mechanism that sustains both inflammatory cell recruitment and lung destruction. This mechanism may underlie disease in other elastin-rich organs and tissues.

Anti-apoA-1 IgG and oxidized LDL are raised in rheumatoid arthritis (RA): potential associations with cardiovascular disease and RA disease activity

OBJECTIVE

To determine whether emerging cardiovascular risk factors such as anti-apolipoprotein A-1 (anti-apoA-1) immunoglobulin (Ig)G and oxidized low density lipoprotein (oxLDL) are associated with cardiovascular disease (CVD), carotid intima-media thickness (IMT), and disease activity in rheumatoid arthritis (RA).

METHOD

We determined the aforementioned associations in 69 RA patients with disease duration of 5 years and 46 controls matched by age, sex, and smoking status. Anti-apoA-1 IgG and oxLDL were measured by enzyme-linked immunosorbent assay (ELISA). Carotid arteries were examined by ultrasound. Disease Activity Score calculated on 28 joints (DAS28) was used to assess disease activity.

RESULTS

CVD prevalence was higher among RA patients than controls (17% vs. 2%, p = 0.01) but there was no difference in IMT (median: 0.67 vs. 0.66, p = 0.33). RA patients had a higher anti-apoA-1 IgG prevalence than controls (20% vs. 0%, p = 0.001). Anti-apoA-1 IgG and oxLDL levels were higher in cases than controls [median: 0.33 vs. 0.175 optical density (OD), p = 0.03; and 121 vs. 37.2 U/L, p = 0.0001, respectively]. Anti-apoA-1 IgG-positive patients had higher levels of oxLDL (median: 140.5 vs. 112 U/L, p = 0.01) than those tested negative. Receiver operating characteristic (ROC) curve analysis showed that only anti-apoA-1 IgG was a modest but significant predictor of CVD [area under the curve (AUC) = 0.65, p = 0.03] in RA patients. oxLDL was significantly associated with RA disease activity, whereas anti-apoA-1 IgG was not.

CONCLUSIONS

Anti-apoA-1 IgG could be a marker of CVD in RA, whereas oxLDL levels seem to reflect RA disease activity. Other causes of CVD than a general increase in atherosclerosis (as determined by IMT measurements) including plaque stability may therefore be of importance to explain the increased incidence of CVD in RA.

Immunosuppressive disorders and risk of anal squamous cell carcinoma: a nationwide cohort study in Denmark, 1978-2005

Compromised immune function may increase the risk of anal squamous cell carcinoma (SCC). We examined the risk of anal SCC in patients with HIV infection and other chronic disorders associated with immunosuppression. A population-based cohort study was conducted using the Danish National Patient Registry and the Danish Cancer Registry (DCR). We identified all patients with a first-time hospital contact or procedure for HIV infection, solid organ transplantation or autoimmune disease or a first-time record of haematologic malignancy in the DCR, 1978-2005, and followed these for a subsequent anal SCC, starting follow-up 1 year after diagnosis of the index disease. Standardised incidence ratios (SIRs) were computed as the ratio of observed to expected numbers of anal SCCs, based on national age-, sex- and period-specific rates. Among 4,488 patients with HIV, we observed 21 anal SCCs with 0.3 expected (SIR: 81.1 (95% confidence interval (CI): 51.6-121.9)). Risk of anal SCC was markedly increased among 5,113 solid organ recipients (SIR: 14.4 (CI: 7.0-26.4)) and 30,165 patients with haematologic malignancies (SIR: 2.3 (CI: 1.1-4.2)) but only moderately increased among 242,114 patients with autoimmune diseases (SIR: 1.3 (CI: 1.0-1.6)). SIRs varied according to type of autoimmune disease and were high in patients with Crohn's disease (SIR: 3.1 (CI: 1.2-6.4)), psoriasis (SIR: 3.1 (CI: 1.8-5.1)), polyarteritis nodosa (SIR: 8.8 (CI: 1.5-29.0)) and Wegener's granulomatosis (SIR: 12.4 (CI: 2.1-40.8)). In conclusion, we found HIV infection, solid organ transplantation, haematologic malignancies and a range of specific autoimmune diseases strongly associated with increased risk of anal SCC.

[Pathogenesis of parodontitis in rheumatic diseases]

Inflammatory periodontal disease (PD) is a common disease worldwide that has a primarily bacterial aetiology and is characterized by dysregulation of the host inflammatory response. The degree of inflammation varies among individuals with PD independently of the degree of bacterial infection, suggesting that alteration of the immune function may substantially contribute to its extent. Factors such as smoking, education, and body mass index (BMI) are discussed as potential risk factors for PD. Most PD patients respond to bacterial invaders by mobilizing their defensive cells and releasing cytokines such as interleukin (IL)-1beta, tumour necrosis factor (TNF)-alpha, and IL-6, which ultimately causes tissue destruction by stimulating the production of collagenolytic enzymes, such matrix metalloproteinases. Recently, there has been growing evidence suggesting an association between PD and the increased risk of systemic diseases, such ateriosclerosis, diabetes mellitus, stroke, and rheumatoid arthritis (RA). PD and rheumatologic diseases such as RA share many pathological aspects and immunological findings.

Autoimmunity to specific citrullinated proteins gives the first clues to the etiology of rheumatoid arthritis

Rheumatoid arthritis (RA) is now clearly a true autoimmune disease with accumulating evidence of pathogenic disease-specific autoimmunity to citrullinated proteins. Citrullination, also termed deimination, is a modification of arginine side chains catalyzed by peptidylarginine deiminase (PAD) enzymes. This post-translational modification has the potential to alter the structure, antigenicity, and function of proteins. In RA, antibodies to cyclic citrullinated peptides are now well established for clinical diagnosis, though we argue that the identification of specific citrullinated antigens, as whole proteins, is necessary for exploring pathogenic mechanisms. Four citrullinated antigens, fibrinogen, vimentin, collagen type II, and alpha-enolase, are now well established, with others awaiting further characterization. All four proteins are expressed in the joint, and there is evidence that antibodies to citrullinated fibrinogen and collagen type II mediate inflammation by the formation of immune complexes, both in humans and animal models. Antibodies to citrullinated proteins are associated with HLA 'shared epitope' alleles, and autoimmunity to at least one antigenic sequence, the CEP-1 peptide from citrullinated alpha-enolase (KIHAcitEIFDScitGNPTVE), shows a specific association with HLA-DRB1*0401, *0404, 620W PTPN22, and smoking. Periodontitis, in which Porphyromonas gingivalis is a major pathogenic bacterium, has been linked to RA in epidemiological studies and also shares similar gene/environment associations. This is also the only bacterium identified that expresses endogenous citrullinated proteins and its own bacterial PAD enzyme, though the precise molecular mechanisms of bacterial citrullination have yet to be explored. Thus, both smoking and Porphyromonas gingivalis are attractive etiological agents for further investigation into the gene/environment/autoimmunity triad of RA.

Cancer risk in patients hospitalised for Graves' disease: a population-based cohort study in Sweden

Background:

The possibility of an association of Graves’ disease (GD) with subsequent cancers raised by certain studies.

Methods:

Using a database on 18 156 hospitalised GD patients, subsequent cancers were ascertained.

Results:

Increased risks of thyroid and parathyroid tumours were limited to the early follow-up period, which is probably a surveillance bias. Cancer sites with observed excess included the mouth and breast, in contrast to decreased risks of colon cancer, melanoma and non-Hodgkin's lymphoma.

Conclusion:

Increased subsequent cancers in GD patients appeared to be balanced by decreased risks at other sites; chance cannot be excluded.

Graves' ophthalmopathy

Graves’ ophthalmopathy, also called Graves’ orbitopathy, is a potentially sight-threatening ocular disease that has puzzled physicians and scientists for nearly two centuries.1 –3 Generally occurring in patients with hyperthyroidism or a history of hyperthyroidism due to Graves’ disease, Graves’ ophthalmopathy is also known as thyroid-associated ophthalmopathy or thyroid eye disease, because it sometimes occurs in patients with euthyroid or hypothyroid chronic autoimmune thyroiditis. The condition has an annual adjusted incidence rate of 16 women and 3 men per 100,000 population.4

This review explores the perplexing relationship between Graves’ ophthalmopathy, hyperthyroidism, and thyroid dermopathy, the associated skin condition. I examine clinical features, histologic findings, and laboratory studies, with an emphasis on mechanisms that could be targeted in the development of new treatments for this debilitating disease.

Effect of tobacco smoking on tissue protein citrullination and disease progression in patients with rheumatoid arthritis

The aim of the present work was to study the effect of tobacco smoking on disease progression in rheumatoid arthritis patients and its relation to anti-cyclical citrullinated peptide (anti-CCP) antibodies. The study included 54 patients; 20 non-smokers, 9 ex-smokers, 14 mild to moderate smokers and 11 heavy smokers. Fifteen normal volunteers were also studied as controls. Disease stage was clinically and radiologically determined, rheumatoid factor (RF) and anti-CCP antibodies were measured in serum. Higher percentage of severe disease (stage III) was seen in heavy smoker patients than mild to moderate smokers (54.6% versus 35.7%) and in moderate smokers than ex-smokers (35.7% versus 33.6%). Lowest percentage of severe disease was seen in non-smokers (15%). RF and anti-CCP were significantly higher in smoker than non-smoker and in heavy than mild to moderate smoker patients (p < 0.01, p < 0.05 and p < 0.01, p < 0.001, respectively). In smoker patients, both RF and anti-CCP antibodies correlated significantly and positively with smoking index (r = 0.581, p < 0.001; r = 0.661, p < 0.001). Also, smoking index and anti-CCP correlated significantly and positively with disease stage (r = 0.424, p < 0.05; r = 0.523, p < 0.01). It appears from our results that, tobacco smoking mostly play a role in progression of rheumatoid arthritis through tissue protein citrullination. So all rheumatoid arthritis patients must quit completely to achieve a good control.

No effect of supplementation with cholecalciferol on cytokines and markers of inflammation in overweight and obese subjects

Epidemiological studies indicate a relation between vitamin D status and autoimmune diseases, and in vitro studies demonstrate an effect of 1,25-dihydroxyvitamin D on immune activation. However, the relation between serum levels of 25-hydroxyvitamin D (25(OH)D) and the effect of vitamin D supplementation on serum levels of cytokines are not settled. In the present study interleukin (IL)-2, IL-4, IL-5, IL-10, IL-12, IL-13, IL-17, intercellular adhesion molecule-1, interferon-gamma, monocyte chemotactic protein-1, and high sensitivity C-reactive protein, were measured in 437 overweight subjects and 324 completed a one year intervention with 40,000 IU vitamin D per week (group DD), 20,000 IU vitamin D per week (group DP), or placebo (group PP). No consistent relations between serum levels of the cytokines and 25(OH)D were found at baseline. In the intervention study, there was no difference in delta values (value at end of study minus value at inclusion) between the three groups regarding the individual cytokines measured, nor was there any indication of a polarization of the T cells towards a Th2 dominant type. In conclusion, we were not able to demonstrate with certainty any significant relation between serum levels of 25(OH)D levels and a number of cytokines and markers of inflammation.

Smoking is associated with increased lesion volumes and brain atrophy in multiple sclerosis

BACKGROUND

Cigarette smoking has been linked to higher susceptibility and increased risk of progressive multiple sclerosis (MS). The effects of smoking on MRI characteristics of patients with MS have not been evaluated.

OBJECTIVES

To compare the MRI characteristics in cigarette smoker and nonsmoker patients with MS.

METHODS

We studied 368 consecutive patients with MS (age 44.0 +/-SD 10.2 years, disease duration 12.1 +/- 9.1 years) comprising 240 never-smokers and 128 (34.8%) ever-smokers (currently active and former smokers). The average number of packs per day smoked (+/-SD) was 0.95 +/- 0.65, and the mean duration of smoking was 18.0 +/- 9.5 years. All patients obtained full clinical and quantitative MRI evaluation. MRI measures included T1, T2, and gadolinium contrast-enhancing (CE) lesion volumes (LVs) and measures of central, global, and tissue-specific brain atrophy. The associations between smoking status and MRI measurements were assessed in regression analysis.

RESULTS

Smoking was associated with increased Expanded Disability Status Scale (EDSS) scores (p = 0.004). The median EDSS scores (interquartile range) in the ever-smoker group and the active-smoker group were both 3.0 (2.0), compared with 2.5 (2.5) in never-smokers. There were adverse associations between smoking and the lesion measures including increased number of CE lesions (p < 0.001), T2 LV (p = 0.009), and T1 LV (p = 0.003). Smoking was associated with decreased brain parenchymal fraction (p = 0.047) and with increases in the lateral ventricle volume (p = 0.001) and third ventricle width (p = 0.023).

CONCLUSIONS

Smoking is associated with increased blood-brain barrier disruption, higher lesion volumes, and greater atrophy in multiple sclerosis.

Rheumatoid arthritis and smoking: putting the pieces together

Besides atherosclerosis and lung cancer, smoking is considered to play a major role in the pathogenesis of autoimmune diseases. It has long been known that there is a connection between rheumatoid factor-positive rheumatoid arthritis and cigarette smoking. Recently, an important gene-environment interaction has been revealed; that is, carrying specific HLA-DRB1 alleles encoding the shared epitope and smoking establish a significant risk for anti-citrullinated protein antibody-positive rheumatoid arthritis. We summarize how smoking-related alteration of the cytokine balance, the increased risk of infections (the possibility of cross-reactivity) and modifications of autoantigens by citrullination may contribute to the development of rheumatoid arthritis.

Smoking and disease progression in multiple sclerosis

BACKGROUND

Although cigarette smokers are at increased risk of developing multiple sclerosis (MS), the effect of smoking on the progression of MS remains uncertain.

OBJECTIVE

To establish the relationship between cigarette smoking and progression of MS using clinical and magnetic resonance imaging outcomes

DESIGN

Cross-sectional survey and longitudinal follow-up for a mean of 3.29 years, ending January 15, 2008.

SETTING

Partners MS Center (Boston, Massachusetts), a referral center for patients with MS.

PATIENTS

Study participants included 1465 patients with clinically definite MS (25.1% men), with mean (range) age at baseline of 42.0 (16-75) years and disease duration of 9.4 (0-50.4) years. Seven hundred eighty patients (53.2%) were never-smokers, 428 (29.2%) were ex-smokers, and 257 (17.5%) were current smokers.

MAIN OUTCOME MEASURES

Smoking groups were compared for baseline clinical and magnetic resonance imaging characteristics as well as progression and sustained progression on the Expanded Disability Status Scale at 2 and 5 years and time to disease conversion to secondary progressive MS. In addition, the rate of on-study change in the brain parenchymal fraction and T2 hyperintense lesion volume were compared.

RESULTS

Current smokers had significantly worse disease at baseline than never-smokers in terms of Expanded Disability Status Scale score (adjusted P < .001), Multiple Sclerosis Severity Score (adjusted P < .001), and brain parenchymal fraction (adjusted P = .004). In addition, current smokers were significantly more likely to have primary progressive MS (adjusted odds ratio, 2.41; 95% confidence interval, 1.09-5.34). At longitudinal analyses, MS in smokers progressed from relapsing-remitting to secondary progressive disease faster than in never-smokers (hazard ratio for current smokers vs never-smokers, 2.50; 95% confidence interval, 1.42-4.41). In addition, in smokers, the T2-weighted lesion volume increased faster (P = .02), and brain parenchymal fraction decreased faster (P = .02).

CONCLUSION

Our data suggest that cigarette smoke has an adverse influence on the progression of MS and accelerates conversion from a relapsing-remitting to a progressive course.

An overview of gene-epigenetic-environmental contributions to MS causation

In this paper we review how environmental factors might interact with genes and epigenetic factors to trigger multiple sclerosis (MS), the latter probably by immune-mediated mechanisms.

Smoking is associated with progressive disease course and increased progression in clinical disability in a prospective cohort of people with multiple sclerosis

BACKGROUND

Multiple sclerosis has a variable disease course. The contribution of modifiable lifestyle factors to disease course has not been well studied, although one cohort has reported that smoking is associated with conversion to secondary progressive MS course and another that smoking is not.

METHODS

We conducted a prospective cohort study of people with MS in Southern Tasmania from 2002 to 2004 with 78% (203/259) of eligible participating and 198 with one or more reviews and confirmed MS. The cohort had a high retention rate (90% (183/203)). The median follow-up time was 909 days. Smoking data were collected at baseline and six-monthly reviews. Clinical disability assessments were conducted annually in conjunction with a real time clinical notification system for relapses. A repeated measures analysis and other statistical methods were used.

RESULTS

Cumulative pack-years (p-y) smoked after cohort entry was associated with an increase in longitudinal MSSS (p < 0.001). Relative to the 0 pack years (p-y) category (in the year prior to the MSSS measure) those in the 0 to 1 p-y category had an adjusted mean difference in MSSS of 0.34 (95% CI 0.28, 0.66); those in the 1 to 2 p-y category had a 0.41 (95% CI -0.03, 0.85) increase; and those in the 2 or more p-y category had a 0.99 (95% CI 0.41, 1.58) increase in MSSS. Similar results were found using a variety of statistical approaches or EDSS as a clinical outcome. Smoking during the cohort period was not associated with relapse (cumulative pack years smoked after cohort entry, HR 0.94 (0.69, 1.26) per pack year).

CONCLUSION

A better understanding of the mechanisms underlying smoking and multiple sclerosis, particularly progressive forms of the disease, may provide new insights for the eventual goal of better treatment and prevention of multiple sclerosis.

Aberrant tumor-associated antigen autoantibody profiles in healthy controls detected by multiplex bead-based immunoassay

There is an increasing amount of emphasis being placed on serological biomarkers as tools for early detection of various cancers. In addition to the tumor-related circulating antigens under current investigation, autoantibodies to tumor-associated antigens are emerging as alternative candidates due to their potential high sensitivity and specificity. Already a number of specific autoantibodies have been identified and several groups have reported on the ability of panels of autoantibodies to discriminate malignant from non-malignant conditions. In this investigation we evaluate tumor-associated antigen autoantibody profiles in a group of healthy individuals. We identify a subset of individuals that demonstrate high levels of autoantibody production across the spectrum of tumor-associated antigens tested. We conclude that this observation is a result of undefined non-malignant autoimmune stimulation. Our findings may be an indication of factors present in the general population that may confound multiplex autoantibody-based diagnostic tests by reducing assay specificity. Such factors will require further characterization and the development of adequate controls in order to improve the performance of diagnostic tests.

Associação entre lúpus eritematoso e tabagismo

FUNDAMENTOS: O lúpus eritematoso é doença crônica, auto-imune, que reúne manifestações exclusivamente cutâneas ou multissistêmicas, caracterizada pela produção de auto-anticorpos contra vários constituintes celulares. OBJETIVO: Avaliar aspectos epidemiológicos, clínicos e, em especial, tabagismo em um estudo envolvendo lúpus eritematoso. MÉTODOS: Foram estudados, retrospectivamente, 80 pacientes com lúpus eritematoso do ambulatório de Dermatologia do Hospital Universitário da Universidade Federal de Juiz de Fora no período de 2002 a 2006. RESULTADOS: A média de idade da instalação da doença foi 40 anos, com acometimento mais freqüente do sexo feminino em relação ao masculino (5,6:1) e a maioria dos pacientes era leucodérmica(60%). Quanto às variedades clínicas, houve predomínio do lúpus eritematoso cutâneo discóide(45%), seguido de lúpus eritematoso agudo (43,75%), lúpus eritematoso subagudo (6,25%), lúpus eritematoso profundo (1,25%), pérnio (1,25%) e túmido (2,5%). A maioria dos pacientes portadores de lúpus eritematoso, 57 (71,25%), era tabagista, 6,25% deles eram ex-tabagistas, e 22,5%, não fumantes. CONCLUSÃO: Corroboram-se as evidências de que o tabagismo seja fator de risco importante para o desenvolvimento de lúpus eritematoso cutâneo, com ou sem acometimento sistêmico, em indivíduos geneticamente predispostos.