Risk modification byCYP1A1andGSTM1polymorphisms in the association of cigarette smoking and systemic lupus erythematosus in a Japanese population

Genetic Polymorphisms of GSTM1 and GPX1 Genes and Smoking Susceptibility in the Saudi Population

Background/Objective/Methods

Glutathione-S-transferase Mu1 (GSTM1) and glutathione peroxidase 1 (GPX1) are known antioxidant enzymes that help protect cells from the oxidative damage that occurs from smoking. This study explored the correlation between GSTM1 and GPX1 levels between a group of smokers with the GSTM1 and GPX1 genes in the Saudi population and a control group and investigated the genetic risk factors in the group of smokers.

Results

The control and smokers' group (n = 50; aged 22.3 ± 3.1 years; BMI 24.6 ± 5.9 kg/m2) were genotyped using quantitative polymerase chain reaction (qPCR). In comparison with the control group, the smokers' group displayed a different genotype disruption of GSTM1 and GPX1. Carriers of the homozygous (TT) genotype of GSTM1 had more than a twofold (OR = 2.71, 95% CI = 0.10-70.79, P = 1.000) smoking risk than the carriers of the heterozygous (CT) genotype. Those with the GPX1 gene showed no risk in the control and smokers' groups. Smokers with the TT/GG combination (homozygous for GPX1 and normal for GPX1) were identified as high risk (OR = 2.58, 95% CI = 0.096-69.341).

Conclusion

The main outcomes showed no significant association between genetic polymorphism of the GSTM1 and GPX1 genes and cigarette smoking in the Saudi Arabian population. However, the results showed a slight decrease in the number of GSTM1 and GPX1 gene modifications among smokers.

Life factors acting on systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a highly heterogeneous autoimmune disease that primarily affects women. Currently, in the search for the mechanisms of SLE pathogenesis, the association of lifestyle factors such as diet, cigarette smoking, ultraviolet radiation exposure, alcohol and caffeine-rich beverage consumption with SLE susceptibility has been systematically investigated. The cellular and molecular mechanisms mediating lifestyle effects on SLE occurrence, including interactions between genetic risk loci and environment, epigenetic changes, immune dysfunction, hyper-inflammatory response, and cytotoxicity, have been proposed. In the present review of the reports published in reputable peer-reviewed journals and government websites, we consider the current knowledge about the relationships between lifestyle factors and SLE incidence and outline directions of future research in this area. Formulation of practical measures with regard to the lifestyle in the future will benefit SLE patients and may provide potential therapy strategies.

Genetic variation in CYP1A1 and AHRR genes increase the risk of systemic lupus erythematosus and exacerbate disease severity in smoker patients

BACKGROUND

Genetic variations of aryl hydrocarbon receptor (AHR) pathway genes could influence the imbalanced immune response to xenobiotics. Therefore, we aimed to investigate the polymorphism of AHR pathway genes in systemic lupus erythematosus (SLE) patients in association with smoking.

METHODS

Genomic DNA from patients (N = 107) and controls (N = 105) of a population from northeast of Iran was used for genotyping of CYP1A1 T>C (rs4646903) and AHRR C>G (rs2292596) variants. The SLEDAI score and smoking status of the patients were registered. The AHR activity was estimated by CYP1A1 and CYP1B1 gene expression in peripheral blood mononuclear cells (PBMC).

RESULTS

The C allele in rs4646903 (odds ratio [OR] = 2.67) and G allele in rs2292596 (OR = 1.79) SNPs were significantly associated with the increased risk of SLE. The AHR pathway was more active in high-risk CYP1A1/AHRR: C/G haplotype. The most severe disease was observed in smoker patients with high-risk haplotype and both smoking (Exp (β) = 9.5) and high-risk CYP1A1/AHRR (C/G) haplotype (Exp (β) = 3.7) can significantly increase the likelihood of having severe (SLEDAI ≥ 20) SLE disease activity.

CONCLUSION

Our findings indicated the association of xenobiotic-metabolizing genes (CYP1A1, AHRR) polymorphisms with the susceptibility to SLE and disease severity regarding the smoking background, suggesting the interaction of gene and environmental risk factors in SLE pathogenesis.

Interaction between the STAT4 rs11889341(T) risk allele and smoking confers increased risk of myocardial infarction and nephritis in patients with systemic lupus erythematosus

Objective

To investigate how genetics influence the risk of smoking-related systemic lupus erythematosus (SLE) manifestations.

Methods

Patients with SLE (n_{discovery cohort}=776, n_{replication cohort}=836) were genotyped using the 200K Immunochip single nucleotide polymorphisms (SNP) Array (Illumina) and a custom array. Sixty SNPs with SLE association (p<5.0×10⁻⁸) were analysed. Signal transducer and activator of transcription 4 (STAT4) activation was assessed in in vitro stimulated peripheral blood mononuclear cells from healthy controls (n=45).

Results

In the discovery cohort, smoking was associated with myocardial infarction (MI) (OR 1.96 (95% CI 1.09 to 3.55)), with a greater effect in patients carrying any rs11889341 STAT4 risk allele (OR 2.72 (95% CI 1.24 to 6.00)) or two risk alleles (OR 8.27 (95% CI 1.48 to 46.27)).

Smokers carrying the risk allele also displayed an increased risk of nephritis (OR 1.47 (95% CI 1.06 to 2.03)). In the replication cohort, the high risk of MI in smokers carrying the risk allele and the association between the STAT4 risk allele and nephritis in smokers were confirmed (OR 6.19 (95% CI 1.29 to 29.79) and 1.84 (95% CI 1.05 to 3.29), respectively).

The interaction between smoking and the STAT4 risk allele resulted in further increase in the risk of MI (OR 2.14 (95% CI 1.01 to 4.62)) and nephritis (OR 1.53 (95% CI 1.08 to 2.17)), with 54% (MI) and 34% (nephritis) of the risk attributable to the interaction. Levels of interleukin-12-induced phosphorylation of STAT4 in CD8+ T cells were higher in smokers than in non-smokers (mean geometric fluorescence intensity 1063 vs 565, p=0.0063).

Lastly, the IL12A rs564799 risk allele displayed association with MI in both cohorts (OR 1.53 (95% CI 1.01 to 2.31) and 2.15 (95% CI 1.08 to 4.26), respectively).

Conclusions

Smoking in the presence of the STAT4 risk gene variant appears to increase the risk of MI and nephritis in SLE. Our results also highlight the role of the IL12−STAT4 pathway in SLE-cardiovascular morbidity.

Interactions Between Genome-Wide Genetic Factors and Smoking Influencing Risk of Systemic Lupus Erythematosus

OBJECTIVE

To identify interactions between genetic factors and current or recent smoking in relation to risk of developing systemic lupus erythematosus (SLE).

METHODS

For the study, 673 patients with SLE (diagnosed according to the American College of Rheumatology 1997 updated classification criteria) were matched by age, sex, and race (first 3 genetic principal components) to 3,272 control subjects without a history of connective tissue disease. Smoking status was classified as current smoking/having recently quit smoking within 4 years before diagnosis (or matched index date for controls) versus distant past/never smoking. In total, 86 single-nucleotide polymorphisms and 10 classic HLA alleles previously associated with SLE were included in a weighted genetic risk score (wGRS), with scores dichotomized as either low or high based on the median value in control subjects (low wGRS being defined as less than or equal to the control median; high wGRS being defined as greater than the control median). Conditional logistic regression models were used to estimate both the risk of SLE and risk of anti-double-stranded DNA autoantibody-positive (dsDNA+) SLE. Additive interactions were assessed using the attributable proportion (AP) due to interaction, and multiplicative interactions were assessed using a chi-square test (with 1 degree of freedom) for the wGRS and for individual risk alleles. Separate repeated analyses were carried out among subjects of European ancestry only.

RESULTS

The mean ± SD age of the SLE patients at the time of diagnosis was 36.4 ± 15.3 years. Among the 673 SLE patients included, 92.3% were female and 59.3% were dsDNA+. Ethnic distributions were as follows: 75.6% of European ancestry, 4.5% of Asian ancestry, 11.7% of African ancestry, and 8.2% classified as other ancestry. A high wGRS (odds ratio [OR] 2.0, P = 1.0 × 10^-51 versus low wGRS) and a status of current/recent smoking (OR 1.5, P = 0.0003 versus distant past/never smoking) were strongly associated with SLE risk, with significant additive interaction (AP 0.33, P = 0.0012), and associations with the risk of anti-dsDNA+ SLE were even stronger. No significant multiplicative interactions with the total wGRS (P = 0.58) or with the HLA-only wGRS (P = 0.06) were found. Findings were similar in analyses restricted to only subjects of European ancestry.

CONCLUSION

The strong additive interaction between an updated SLE genetic risk score and current/recent smoking suggests that smoking may influence specific genes in the pathogenesis of SLE.

Association Between Cigarette Smoking and Systemic Lupus Erythematosus: An Updated Multivariate Bayesian Metaanalysis

OBJECTIVE

The association between cigarette smoking and the risk of systemic lupus erythematosus (SLE) remains a matter for debate. Additionally, the effect of the change of smokers' demographics on the risk of development of SLE over time has not been formally addressed. We aimed to examine the association between cigarette smoking and the risk of SLE by performing an updated metaanalysis.

METHODS

A literature search using keywords including "lupus," "smoking," "cigarette," "environmental," "autoimmune," and "connective tissue disease" was performed in computerized databases to identify studies addressing the relationship between cigarette smoking and SLE occurrence. A Bayesian metaanalysis was conducted by computing the log-OR between current and never smokers, and between former and never smokers. The average log-OR (subsequently converted to OR) and their corresponding 95% credible intervals (CrI) were calculated. The effect of publication time, sex, and age of patients with SLE on the effect sizes was examined by multivariate metaregression.

RESULTS

Data aggregation of 12 eligible studies comprising 3234 individuals who developed SLE and 288,336 control subjects revealed a significant association between SLE occurrence and current smoking status (OR 1.54, 95% CrI 1.06-2.25), while only a non-significant trend was demonstrated between SLE occurrence and former smoking status (OR 1.39, 95% CrI 0.95-2.08). Publication time, sex, and the mean age of patients with SLE did not explain the heterogeneity of the effect sizes.

CONCLUSION

Current smoking status is associated with risk of SLE. Sex and age of patients with SLE had no significant effect on the risk of SLE over time.

Uncovering potential lncRNAs and nearby mRNAs in systemic lupus erythematosus from the Gene Expression Omnibus dataset

Aim: The aim of this study was to find potential differentially expressed long noncoding RNAs (lncRNAs) and mRNAs in systemic lupus erythematosus. Materials & methods: Differentially expressed lncRNAs and mRNAs were obtained in the Gene Expression Omnibus dataset. Functional annotation of differentially expressed mRNAs was performed, followed by protein-protein interaction network analysis. Then, the interaction network of lncRNA-nearby targeted mRNA was built. Results: Several interaction pairs of lncRNA-nearby targeted mRNA including NRIR-RSAD2, RP11-153M7.5-TLR2, RP4-758J18.2-CCNL2, RP11-69E11.4-PABPC4 and RP11-496I9.1-IRF7/HRAS/PHRF1 were identified. Measles and MAPK were significantly enriched signaling pathways of differentially expressed mRNAs. Conclusion: Our study identified several differentially expressed lncRNAs and mRNAs. And their interactions may play a crucial role in the process of systemic lupus erythematosus.

p53 protein expression affected by TP53 polymorphism is associated with the biological behavior and prognosis of low rectal cancer

Low rectal cancer is a subtype of colorectal cancer at a special anatomic site with distinct biological behavior. TP53 is one of the most important cancer suppressor genes, and its structural variation and abnormal expression has been revealed to be associated with multiple cancer types. However, to the best of our knowledge, the association of p53 protein expression with its gene polymorphism, biological behavior and prognosis in low rectal cancer has not been clarified. Therefore, the current study aimed to explore these associations. In the present study, 347 patients with low rectal cancer and 353 controls were enrolled. Kompetitive Allele-Specific Polymerase Chain Reaction was used to detect five polymorphic sites of the TP53 gene (rs1042522, rs12947788, rs1625895, rs2909430 and rs12951053), while immunohistochemistry was used to detect the protein expression of TP53. The associations between p53 protein expression and TP53 polymorphism, biological behavior and prognosis in low rectal cancer were systematically analyzed. In low rectal cancer, p53 protein expression was markedly higher in TP53 rs1042522 mutant carriers compared with that in other genotypes where expression was higher in poorly differentiated, III-IV phase and T3-4 phase tumors, and in III-IV phase female patients. The survival time of patients with low p53 protein expression was evidently longer in females, non-smokers and patients >60 years old. In summary, p53 protein expression was identified to be affected by TP53 rs1042522 polymorphism, and was associated with the biological behavior and prognosis of low rectal cancer. TP53 rs1042522 and the associated protein expression could be used as indicators for biological behavior and prognosis in low rectal cancer.

Impact of tobacco smoking upon disease risk, activity and therapeutic response in systemic lupus erythematosus: A systematic review and meta-analysis

Systemic lupus erythematosus (SLE) is a complex disease with variable presentations, course and prognosis. Published studies present conflicting data regarding the impact of cigarette smoking on SLE risk, disease activity, clinical manifestations and treatment response. We performed a comprehensive literature search using Medline, EMBASE and the Cochrane Collaboration database, and hand searches of relevant bibliographies. All original studies investigating the relationship between smoking and SLE were included in TABALUP. Two investigators systematically extracted data from the relevant studies. When possible, meta-analyses were performed. The meta-analysis of 9 case-controls studies show an increased risk of SLE in current-smokers compared to never-smokers (OR: 1.49 [95%CI: 1.06-2.08]), while former-smokers were not at increased risk of SLE. Data on passive smoking remains scarce and controversial. Pooled analysis studies did not find an over-risk of anti-dsDNA, anti-Sm or anti-SSA positivity according to smoking status. Tobacco smoking significantly reduced the therapeutic effectiveness of hydroxychloroquine in cutaneous lesions (pooled OR 0.53; 95%CI: 0.305-0.927) and belimumab in systemic manifestations (HR 0.10; 95% CI 0.02-0.43). In addition to its usual adverse effects, cigarette smoking is a risk factor of SLE and negatively influences the course of the disease and its treatment. We believe that smoking cessation should be one of the main target of physicians treating SLE patients.

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

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

Cigarette smoking and the pathogenesis of systemic lupus erythematosus

INTRODUCTION

Systemic lupus erythematosus (SLE) is a multi-system inflammatory autoimmune disease of incompletely understood etiology. It is thought that environmental exposures 'trigger' or accelerate the disease in genetically-predisposed individuals. Areas covered: Substantial epidemiological evidence exists to support the association between cigarette smoking and the risk of incident SLE. Recent evidence points to current smoking as the specific risk factor, with decreasing risk 5 years after smoking cessation, and the greatest risk for disease characterized by the presence of SLE-specific autoantibodies. Research has begun to search for possible explanations for the temporal nature of the relationship between current smoking and autoantibody positive-SLE. Here we review potential biologic mechanisms linking smoking and SLE risk, including effects upon T and B cells, inflammatory cytokines, oxidative stress, and the formation of short-lived DNA adducts. Expert commentary: The directions for future research in this field include studies of gene-environment interactions, epigenetics, metabolomics and putative biologic mechanisms.

Estrogen receptor alpha gene (ESR1) polymorphism and its interaction with smoking and drinking contribute to susceptibility of systemic lupus erythematosus

The aim of this study is to investigate the association of estrogen receptor alpha gene (ESR1) polymorphisms, additional gene-gene, and gene-environment interaction with systemic lupus erythematosus (SLE) risk. SNPStats (available online at http://bioinfo.iconcologia.net/SNPstats ) was used to investigate the Hardy-Weinberg equilibrium (HWE) in controls and association between SNP and SLE risk. Generalized multifactor dimensionality reduction (GMDR) was used to screen the interactions among SNPs and environmental risk factors; SLE risk was significantly higher in carriers of rs2234693 C allele than those with TT (TC + CC versus TT), adjusted OR (95%CI) = 1.57 (1.21-2.06), and was also higher in carriers of rs9340799 G allele than those with AA (AG + GG versus AA), adjusted OR (95%CI) = 1.68 (1.24-2.13). However, we also find no association between rs2228480 and SLE risk after covariates adjustment. We found a significant two-locus model (p = 0.0010) involving rs2234693 and smoking; the cross-validation consistency of this model was 10/10, and the testing accuracy was 62.70%. Smokers with TC or CC of rs2234693 genotype have the highest SLE risk, compared to never-smokers with TT of rs2234693 genotype, OR (95%CI) was 2.50 (1.65-3.42), after covariates adjustment for gender, age, alcohol drinking, and BMI. We found that C allele of rs2234693 and G allele of rs9340799 within ESR1 gene, their interaction between rs2234693 and current smoking were all associated with increased SLE risk.

Cigarette smoking and the risk of systemic lupus erythematosus, overall and by anti-double stranded DNA antibody subtype, in the Nurses' Health Study cohorts

OBJECTIVES

Systemic lupus erythematosus (SLE) is a heterogeneous autoimmune disease, subtyped according to clinical manifestations and autoantibodies. Evidence concerning cigarette smoking and SLE risk has been conflicting. We investigated smoking and SLE risk, overall and by anti-double stranded DNA (dsDNA) presence, in two prospective cohort studies.

METHODS

The Nurses' Health Study (NHS) enrolled 121 701 US female nurses in 1976; Nurses' Health Study II (NHSII) enrolled 116 430 in 1989. Lifestyle, environmental and medical data were collected through biennial questionnaires. Incident SLE was confirmed by medical record review. Cox regression models estimated HRs of SLE, overall and by dsDNA subtype, in association with time-varying smoking status and cumulative smoking pack-years through the 2-year cycle prior to diagnosis, controlling for potential confounders.

RESULTS

Among 286 SLE cases identified (159 in NHS (1978-2012) and 127 in NHSII (1991-2013)), mean age was 49.2 (10.3) years and 42% were dsDNA+ at SLE diagnosis. At baseline, 45% of women had ever smoked, 51% of whom currently smoked. Compared with never smokers, current smokers had increased dsDNA+ SLE risk (HR 1.86 (1.14-3.04)), whereas past smokers did not (HR 1.31 (0.85-2.00)). Women who smoked >10 pack-years (vs never) had an elevated dsDNA+ SLE risk (HR 1.60(95% CI 1.04 to 2.45)) compared with never smokers. No associations were observed between smoking status or pack-years and overall SLE or dsDNA- SLE.

CONCLUSION

Strong and specific associations of current smoking and >10 pack-years of smoking with dsDNA+ SLE were observed. This novel finding suggests smoking is involved in dsDNA+ SLE pathogenesis.

Environmental exposures and the development of systemic lupus erythematosus

PURPOSE OF REVIEW

This review examines evidence relating environmental factors to the development of systemic lupus erythematosus (SLE).

RECENT FINDINGS

The strongest epidemiologic evidence exists for the associations of silica, cigarette smoking, oral contraceptives, postmenopausal hormone therapy and endometriosis, with SLE incidence. Recent studies have also provided robust evidence of the association between alcohol consumption and decreased SLE risk. There are preliminary, conflicting or unsubstantiated data that other factors, including air pollution, ultraviolet light, infections, vaccinations, solvents, pesticides and heavy metals such as mercury, are related to SLE risk. Biologic mechanisms linking environmental exposures and SLE risk include increased oxidative stress, systemic inflammation and inflammatory cytokine upregulation, and hormonal triggers, as well as epigenetic modifications resulting from exposure that could lead to SLE.

SUMMARY

Identifying the environmental risk factors related to risk of SLE is essential as it will lead to increased understanding of pathogenesis of this complex disease and will also make risk factor modification possible for those at increased risk.

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

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

Healthy lifestyle habits for patients with systemic lupus erythematosus: A systemic review

OBJECTIVES

To assess the effects of lifestyle habits on the disease activity and damage, the occurrence of flares and quality of life of people with systemic lupus erythematosus (SLE).

METHODS

A systematic literature review was performed. MEDLINE, EMBASE, and SCI/SSCI were searched. Experimental and observational studies evaluating the effect of lifestyles for SLE patients were included. Two independent reviewers selected studies and extracted relevant data. Critical appraisal of the studies was assessed following SIGN criteria.

RESULTS

Eligibility criteria were met by 21 studies, five analyzed the effect of tobacco consumption, nine the effect of physical exercise and seven the effect of diet. Three studies on tobacco observed an association with increased SLE activity and the onset of cutaneous damage. The studies on physical exercise, of heterogeneous quality, reported that aerobic activity is safe for SLE patients, leading to an increase of tolerance to exercise, physical and functional capacity for those with moderate or low activity. A reduction in fatigue, anxiety and depression, as well as improved quality of life, is also suggested though evidence for these outcomes is limited. Better-quality studies on diet analyzed the effect of polyunsaturated fatty acids on disease activity. Three of the four randomized placebo-controlled trials revealed a positive effect both on overall SLE indices and individual symptoms that affect patients.

CONCLUSIONS

Tobacco smoking increases the risk of skin damage and disease activity in patients with SLE. A diet rich in polyunsaturated fatty acids, avoiding a sedentary lifestyle and supervised exercise should be recommended for patients with stable SLE.

Environmental influences on systemic lupus erythematosus expression

The etiology of systemic lupus erythematosus (SLE) is unknown, but multiple genetic, epigenetic, and environmental risk factors have been implicated. The inheritance of genes alone is not sufficient for developing SLE, suggesting the influence of environmental triggers on disease expression. Despite the tremendous amount of progress in elucidating potential environmental risk factors for SLE, much more needs to be done. An interdisciplinary approach to studies of the causes and, ultimately, prevention of SLE is needed. This article reviews what is understood about the epidemiology of the relationship between environmental exposures and SLE, in addition to emerging areas of study.

The null polymorphism of the GSTM1/T1 gene is not associated with susceptibility to systemic lupus erythematosus: a meta-analysis

Previous studies have suggested that the null polymorphism of the glutathione S-transferases M1/T1 (GSTM1/T1) gene may be associated with the risk of developing systemic lupus erythematosus (SLE). We further explored this potential association using a meta-analysis. A systematic literature search was carried out in the scientific literature databases and we used odds ratios (OR) and 95 % confidence intervals (CIs) to evaluate the strength of this association. All statistical analyses were calculated using Stata software 11.0, and Bonferroni correction was used to adjust the p values. Nine eligible articles with 1,850 patients and 2,826 controls were identified. Our results showed the null polymorphism of the GSTM1 gene was associated with SLE in East Asians (OR 1.32, 95 % CI 1.04-1.69, p = 0.024), but not in Europeans and Africans. However, when Bonferroni corrections were applied (p = 0.05/2 = 0.025), we could not be sure of this association. We further analysed the associations between the GSTT1 gene null polymorphism and the risk of SLE. The results of this investigation showed that this null polymorphism was not associated with susceptibility to SLE in all included populations. In conclusion, the null polymorphism of GSTM1/T1 gene may not be associated with the risk of SLE. More studies are needed to confirm this lack of association between key oxidative defense genes and susceptibility to SLE in the future.

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.

The association among antioxidant enzymes, autoantibodies, and disease severity score in systemic lupus erythematosus: comparison of neuropsychiatric and nonneuropsychiatric groups

Background. Antioxidative capacity plays an important role in the severity of systemic lupus erythematosus (SLE), which is characterized by autoantibodies. This study aimed to determine the relationship among autoantibody titers, antioxidative stress reserve, and severity of SLE. Methods. The autoantibody titers, clinical markers, antioxidant enzyme levels, and disease activity index (SLEDAI-2k) of 32 SLE patients and 16 healthy controls were compared. We also compared both the neuropsychiatric (NPSLE) and nonneuropsychiatric (non-NPSLE) groups. Results. Superoxide dismutase in red blood cells was significantly lower in the SLE than in the control group. CRP levels are significant higher in SLE patients than in control group (P = 0.034). Among the autoantibodies, anti-U1RNP (P = 0.008), a-Sm (P = 0.027), and anti-ribosomal p (P = 0.028) significantly negatively correlated with glutathione levels. There has no significant correlation between SLE disease activity indexes (SLEDAI) and levels of C3, C4, and antioxidant enzymes. Conclusions. Erythrocyte superoxide dismutase is significantly lower in both NPSLE and non-NPSLE groups. SLE patients have both higher CRP and autoantibodies level and decreased superoxide dismutase level than the healthy control group.

Oxidative stress and its biomarkers in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune inflammatory disease whose etiology remains largely unknown. The uncontrolled oxidative stress in SLE contributes to functional oxidative modifications of cellular protein, lipid and DNA and consequences of oxidative modification play a crucial role in immunomodulation and trigger autoimmunity. Measurements of oxidative modified protein, lipid and DNA in biological samples from SLE patients may assist in the elucidation of the pathophysiological mechanisms of the oxidative stress-related damage, the prediction of disease prognosis and the selection of adequate treatment in the early stage of disease. Application of these biomarkers in disease may indicate the early effectiveness of the therapy. This review is intended to provide an overview of various reactive oxygen species (ROS) formed during the state of disease and their biomarkers linking with disease. The first part of the review presents biochemistry and pathophysiology of ROS and antioxidant system in disease. The second part of the review discusses the recent development of oxidative stress biomarkers that relates pathogenesis in SLE patients and animal model. Finally, this review also describes the reported clinical trials of antioxidant in the disease that have evaluated the efficacy of antioxidant in the management of disease with ongoing conventional therapy.

Gene-environment interaction in autoimmune disease

Autoimmune disease manifests in numerous forms, but as a disease group is relatively common in the population. It is complex in aetiology, with genetic and environmental determinants. The involvement of gene variants in autoimmune disease is well established, and evidence for significant involvement of the environment in various disease forms is growing. These factors may act independently, or they may interact, with the effect of one factor influenced by the presence of another. Identifying combinations of genetic and environmental factors that interact in autoimmune disease has the capacity to more fully explain disease risk profile, and to uncover underlying molecular mechanisms contributing to disease pathogenesis. In turn, such knowledge is likely to contribute significantly to the development of personalised medicine, and targeted preventative approaches. In this review, we consider the current evidence for gene-environment (G-E) interaction in autoimmune disease. Large-scale G-E interaction research efforts, while well-justified, face significant practical and methodological challenges. However, it is clear from the evidence that has already been generated that knowledge on how genes and environment interact at a biological level will be crucial in fully understanding the processes that manifest as autoimmunity.

Clinical implications of shared genetics and pathogenesis in autoimmune diseases

Many endocrine diseases, including type 1 diabetes mellitus, Graves disease, Addison disease and Hashimoto disease, originate as an autoimmune reaction that affects disease-specific target organs. These autoimmune diseases are characterized by the development of specific autoantibodies and by the presence of autoreactive T cells. They are caused by a complex genetic predisposition that is attributable to multiple genetic variants, each with a moderate-to-low effect size. Most of the genetic variants associated with a particular autoimmune endocrine disease are shared between other systemic and organ-specific autoimmune and inflammatory diseases, such as rheumatoid arthritis, coeliac disease, systemic lupus erythematosus and psoriasis. Here, we review the shared and specific genetic background of autoimmune diseases, summarize their treatment options and discuss how identifying the genetic and environmental factors that predispose patients to an autoimmune disease can help in the diagnosis and monitoring of patients, as well as the design of new treatments.

Interaction between glutathione and apoptosis in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is characterized by imbalance redox state and increased apoptosis. The activation, proliferation and cell death of lymphocytes are dependent on intracellular levels of glutathione and controlled production of reactive oxygen species (ROS). Changes in the intracellular redox environment of cells, through oxygen-derived free radical production known as oxidative stress, have been reported to be critical for cellular immune dysfunction, activation of apoptotic enzymes and apoptosis. The shift in the cellular GSH-to-GSSG redox balance in favor of the oxidized species, GSSG, constitutes an important signal that can decide the fate of the abnormal apoptosis in the disease. The current review will focus on four main areas: (1) general description of oxidative stress markers in SLE, (2) alteration of redox state and complication of disease, (3) role of redox mechanisms in the initiation and execution phases of apoptosis, and (4) intracellular glutathione and its checkpoints with lymphocyte apoptosis which represent novel targets for pharmacological intervention in SLE.