Association of TNF-alpha gene polymorphisms with systemic lupus erythematosus in Taiwanese patients

Tumor necrosis factor‑α in systemic lupus erythematosus: Structure, function and therapeutic implications (Review)

Tumor necrosis factor‑α (TNF‑α) is a pleiotropic pro‑inflammatory cytokine that contributes to the pathophysiology of several autoimmune diseases, such as multiple sclerosis, inflammatory bowel disease, rheumatoid arthritis, psoriatic arthritis and systemic lupus erythematosus (SLE). The specific role of TNF‑α in autoimmunity is not yet fully understood however, partially, in a complex disease such as SLE. Through the engagement of the TNF receptor 1 (TNFR1) and TNF receptor 2 (TNFR2), both the two variants, soluble and transmembrane TNF‑α, can exert multiple biological effects according to different settings. They can either function as immune regulators, impacting B‑, T‑ and dendritic cell activity, modulating the autoimmune response, or as pro‑inflammatory mediators, regulating the induction and maintenance of inflammatory processes in SLE. The present study reviews the dual role of TNF‑α, focusing on the different effects that TNF‑α may have on the pathogenesis of SLE. In addition, the efficacy and safety of anti‑TNF‑α therapies in preclinical and clinical trials SLE are discussed.

Correlation between TNF-α -308 and +489 Gene Polymorphism and Acute Exacerbation of Chronic Obstructive Pulmonary Diseases

Acute exacerbation of chronic obstructive pulmonary disease (AECOPD) is becoming a common respiratory disease, leading to increased morbidity and mortality worldwide. Tumor necrosis factor-alpha (TNF-α) is a powerful proinflammatory cytokine involved in the pathogenesis of AECOPD. Therefore, we proposed a close correlation between the TNF-α polymorphism [-308G/A (rs1800629), +489G/A (rs1800610)] and the disease progress of patients with AECOPD. Comparison of the TNF-α genotypes between the 198 AECOPD diagnosed patients groups and 195 healthy peoples suggested their significant differences of the three genotypes (AA, GA, GG) distribution for TNF-α -308 (P < 0.05), but no differences of that for TNF-α +489. We found that patients with TNF-α -308 GA/AA genotypes showed smaller adjacent arterial diameter, thicker bronchial wall, higher bronchial artery ratio, higher bronchial wall grading, and higher frequency of acute exacerbations than those with TNF-α -308 GG genotype. Patients with TNF-α +489 GA/AA genotypes showed the same AECOPD properties as patients with TNF-α -308 except for the high frequency of acute exacerbations. Further experiment showed that the TNF-α -308 and+489 gene polymorphisms could affect the expression level of TNF-α in macrophages, suggesting the involvement of the macrophage population in disease regulation of AECOPD patients with TNF-α -308G/A and+489G/A genotype heterogeneity. In conclusion, the TNF-α -308 G/A genotype was related to AECOPD susceptibility and progress, while the TNF-α +489G/A genotype was related to AECOPD progress, but not AECOPD susceptibility.

Synergetic Interaction of HLA-DRB1*07 Allele and TNF-Alpha - 863 C/A Single Nucleotide Polymorphism in the Susceptibility to Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is an inflammatory autoimmune disease which is characterized by dysregulation of various cytokines propagating the inflammatory processes that is responsible for tissue damage. Tumor necrosis factor alpha (TNF-α) is one of the most important immunoregulatory cytokines that has been implicated in the different autoimmune diseases including SLE. Two hundred and two patients with SLE and 318 controls were included in the study. The TNF-α gene promoter region (from - 250 to - 1000 base pairs) was analyzed by direct Sanger's DNA sequencing method to find promoter variants associated with South Indian SLE patients. We have analyzed six TNF-α genetic polymorphisms including, - 863C/A (rs1800630), - 857C/T (rs1799724), - 806C/T (rs4248158), - 646G/A (rs4248160), - 572A/C (rs4248161) and - 308G/A (rs1800629) in both SLE patients and controls. We did not find association of TNF-α gene promoter SNPs with SLE patients. However, the - 863A (rs1800630) allele showed association with lupus nephritis phenotype in patients with SLE (OR: 1.62, 95%CI 1.04-2.53, P = 0.034). We found serum TNF-α level was significantly elevated in SLE cases as compared to control and found no association with any of the polymorphisms. The haplotype analysis revealed a significant protective association between the wild TNF-α alleles at positions - 863C, - 857C, - 806C, - 646G, - 572A and - 308G (CCCGAG) haplotype with lupus nephritis phenotype (OR 0.53, 95% CI 0.35-0.82, P = 0.004). Additionally, the TNF-α - 863 C/A (rs1800630) polymorphism and HLA-DRB1*07 haplotype showed significant differences between SLE patients and controls (OR 4.79, 95% CI 1.73-13.29, P = 0.0009). In conclusion, TNF-α - 863A allele (rs1800630) polymorphism is associated with increased risk of nephritis in South Indian SLE patients. We also found an interaction between HLA-DRB1*07 allele with TNF-α - 863 C/A promoter polymorphism giving supportive evidence for the tight linkage disequilibrium between TNF-α promoter SNPs and MHC class II DRB1 alleles.

Evaluation of TNF-α genetic polymorphisms as predictors for sepsis susceptibility and progression

Background

The goal of the study was to evaluate a potential role for tumor necrosis factor alpha (TNF-α) genetic variability as biomarker in sepsis. In particular, we aimed to determine if single nucleotide polymorphisms (SNPs) of TNF-α gene are associated with sepsis in terms of risk, severity and outcome.

Methods

We performed a prospective study on 163 adult critically ill septic patients (septic shock 65, sepsis 98, further divided in 40 survivors and 123 deceased) and 232 healthy controls. Genotyping of TNF-α SNPs (-308G/A, -238G/A, -376G/A and +489G/A) was performed for all patients and controls and plasma cytokine levels were measured during the first 24 h after sepsis onset.

Results

TNF-α +489G/A A-allele carriage was associated with significantly lower risk of developing sepsis and sepsis shock (AA+AG vs GG: OR = 0.53; p = 0.004; 95% CI = 0.34–0.82 and OR = 0.39; p = 0.003; 95% CI = 0.21–0.74, respectively) but not with sepsis-related outcomes. There was no significant association between any of the other TNF-α promoter SNPs, or their haplotype frequencies and sepsis or septic shock risk. Circulating TNF-α levels were higher in septic shock; they were not correlated with SNP genotype distribution; GG homozygosity for each polymorphism was correlated with higher TNF-α levels in septic shock.

Conclusions

TNF-α +489G/A SNP A-allele carriage may confer protection against sepsis and septic shock development but apparently does not influence sepsis-related mortality. Promoter TNF-α SNPs did not affect transcription and were not associated with distinct sepsis, septic shock risk or outcomes.

Cytotoxic Function and Cytokine Production of Natural Killer Cells and Natural Killer T-Like Cells in Systemic Lupus Erythematosis Regulation with Interleukin-15

Natural killer cells and NKT-like cells are the first line immune defense against tumor and virus infection. Deficient NK and NKT-like cell effector function may contribute to increased susceptibility to infection in SLE patients. We sought to examine the perforin and granzyme B expression, interferon-gamma (IFN-γ), and tumor-necrosis factor-alpha (TNF-α) production and CD107a degranulation of NK and NKT-like cells from SLE patients and their regulation by IL-15. We established that (1) perforin expression on SLE NK cells was decreased but unrelated to disease activity; (2) the MFI of granzyme B was increased in NK cells from SLE patients with active disease, associated with increased percentages of granzyme B⁺ CD56^bright NK cells; (3) NK cells from active SLE patients, both CD56^dim and CD56^bright NK subsets, produced higher IFN-γ compared to controls; (4) CD56^dim, but not CD56^bright NK cells from active SLE patients, produced lower TNF-α, compared to inactive SLE patients and controls; (5) CD107a degranulation of SLE NK cells was comparable to controls; (6) IL-15 enhanced perforin/granzyme B expression, IFN-γ/TNF-α production, and CD107a degranulation of NK cells from SLE patients; and (7) similar observations were found for CD56⁺CD3⁺ NKT-like cells. Taken together, we demonstrated the differential expression of the heightened granzyme B and decreased TNF-α in NK and NKT-like cells in SLE patients. Higher granzyme B expression of NK and NKT-like cells in active SLE patients, further enhanced by circulating IL-15, may contribute to the maintenance of inflammation in SLE.

Serum IP-10 is useful for identifying renal and overall disease activity in pediatric systemic lupus erythematosus

BACKGROUND

Traditional serological biomarkers often fail to assess systemic lupus erythematosus (SLE) disease activity and discriminate lupus nephritis (LN). The aim of this study was to identify novel markers for evaluating renal and overall disease activity in Chinese patients with pediatric systemic lupus erythematosus (pSLE).

METHODS

The study included 46 patients with pSLE (35 girls, 11 boys; average age 13.3 ± 2.6 years) and 31 matched healthy controls (22 girls, 9 boys; average age 12.3 ± 2.4 years). The SLE Disease Activity Index (SLEDAI) and renal SLEDAI were used to assess disease activity. Nine different soluble mediators in plasma, including tumor necrosis factor alpha (TNF-α), platelet-derived growth factor-BB (PDGF-BB), interferon (IFN) gamma inducible protein 10 (IP-10), interleukin (IL)-1β, IFN-γ, IL-17A, IL-2, Fas and Fas ligand, were measured by Luminex assay and compared between patients with active and inactive pSLE as well as between patients with pSLE with active and inactive renal disease. Receiver operating characteristic curve analysis was used to measure the discrimination accuracy.

RESULTS

Of the 46 patients with pSLE, 30 (65.2%) had LN. These patients had significantly elevated levels of serum TNF-α, PDGF-BB, IP-10 and Fas. The serum levels of IP-10 were also significantly higher in patients with active pSLE. We found that IP-10 was also more sensitive and specific than conventional laboratory parameters, including anti-double-stranded DNA and complement components C3 and C4, for distinguishing active lupus from quiescent lupus. The serum level of IP-10 was also significantly increased in children with pSLE with active renal disease relative to those with inactive renal disease. There was also a positive correlation between serum IP-10 levels and renal SLEDAI scores as well as with 24 h urine protein.

CONCLUSIONS

Serum IP-10 is useful for identifying renal and overall disease activity in children with pSLE.

TNF-α gene polymorphisms and expression

Tumor necrosis factor alpha (TNF-α) is a proinflammatory cytokine with an important role in the pathogenesis of several diseases. Its encoding gene is located in the short arm of chromosome 6 in the major histocompatibility complex class III region. Most of the TNF-α gene polymorphisms are located in its promoter region and they are thought to affect the susceptibility and/or severity of different human diseases. This review summarizes the data related to the association between TNF-α gene and its receptor polymorphisms, and the development of autoimmune diseases. Among these polymorphisms the -308G/A TNF-α promotor polymorphism has been associated several times with the the development of autoimmune diseases, however some discrepant results have been recorded. The other TNF-α gene polymorphisms had little or no association with autoimmune diseases. Current results about the molecules controlling TNF-α expression are also presented. The discrepancy between different records could be related partly to either the differences in the ethnic origin or number of the studied individuals, or the abundance and activation of other molecules that interact with the TNF-α promotor region or other elements.

Genetic Variants That Are Associated with Neuropsychiatric Systemic Lupus Erythematosus

OBJECTIVE

While genetic risks have been implicated in systemic lupus erythematosus (SLE), the involvement of various genotypes in neuropsychiatric SLE (NPSLE) remains uncertain. The present metaanalysis aimed to combine data from different studies and evaluate the association between each genotype and the risk of developing NPSLE.

METHODS

Studies were searched and retrieved from online databases (PubMed, EMBASE, BIOSIS, and ScienceDirect). Case-control studies were chosen if they reported genotype frequencies of the γ Fc region (FCγR) receptors II-A, III-A, and III-B; tumor necrosis factor-α (TNF-α); mannan-binding lectin (MBL); integrin alpha M (ITGAM); interleukin (IL) 1, IL-1β, and IL-6; IL-10 promoter; and vitamin D genes. The OR were used to assess the strength of this association between patients with NPSLE and SLE.

RESULTS

A total of 33 studies were considered in this metaanalysis. The results suggest that these genotypes demonstrated a significant association with NPSLE: the homozygous FCγR IIIa 158 FF genotype (OR 1.89, p = 0.03 for FF vs VV + FV), heterozygous FCγR IIIb NA1/2 genotype (OR 2.14, p = 0.03 for NA1/2 vs NA1/1; OR 1.81, p = 0.04 for NA1/2 vs NA1/1 + NA2/2), and homozygous ITGAM rs1143679 HH genotype (OR 3.39, p = 0.04 for HH vs RH; OR 3.11, p = 0.048 for HH vs RR + RH). Polymorphisms of the TNF-α, MBL2, IL-1, IL-1β, IL-6, IL-10 promoter, and vitamin D receptor genes did not show a statistically significant association with the risk of developing NPSLE (p > 0.05).

CONCLUSION

This metaanalysis indicates that polymorphisms in the pathways of immune complex clearance, such as the FcγRIIIa, FcγRIIIb, and ITGAM genotypes, are potential susceptibility genes for NPSLE.

Ovarian function and reproductive outcomes of female patients with systemic lupus erythematosus and the strategies to preserve their fertility

Systemic lupus erythematosus (SLE) is a chronic autoimmune systemic disease that mainly affects women of reproductive age. Emerging data from recent molecular studies show us that estrogen hormone plays a central role in the development of this disease. By acting via its cognate receptors ERα and ERβ expressed on immune cells, estrogen can modulate immune function in both the innate and adaptive immune responses. Interestingly, estrogen may also evoke autoimmune responses after binding to B lymphocytes leading to the generation of high-affinity autoantibodies and proinflammatory cytokines (so-called estrogen-induced autoimmunity). Unfortunately, reproductive function of young female patients with this disease is commonly compromised by different pathophysiologic processes. First, ovarian reserve is diminished even in the presence of mild disease suggesting a direct impact of the disease itself on ovarian function possibly due to ovarian involvement in the form of autoimmune oophoritis. Second, SLE patients with severe manifestations of the disease are treated with alkylating chemotherapy agent cyclophosphamide. Cyclophosphamide and other drugs of alkylating category have the highest gonadotoxicity. Therefore, SLE patients exposed to cyclophosphamide have a much higher risk of developing infertility and premature ovarian failure than do the counterparts who are treated with other less toxic treatments. Third, the functions of the hypothalamic pituitary ovarian axis are perturbed by chronic inflammatory state. And finally adverse pregnancy outcomes are more commonly observed in SLE patients such as fetal loss, preterm birth, intrauterine fetal growth restriction, preeclampsia-eclampsia, and fetal congenital heart block. We aimed in this review article to provide the readers an update on how estrogen hormone closely interacts with and induces lupus-prone changes in the immune system. We also discuss ovarian function and other reproductive outcomes in SLE patients and the current strategies to preserve their fertility in the light of the most recent evidence-based findings of the clinical trials and molecular studies.

Tumor necrosis factor-α -308G/A gene polymorphism in Egyptian children with immune thrombocytopenic purpura

Immune thrombocytopenic purpura (ITP) is an autoimmune disease characterized by increased platelet destruction. Although the cause of ITP remains unclear, it is accepted that both environmental and genetic factors play an important role in the development of the disease. Children with ITP have a T-helper 1-type cytokine pattern with elevated levels of tumor necrosis factor-alpha (TNF-α) as in most autoimmune diseases. Researchers have shown that polymorphism in the TNF-α gene at position -308 affects gene transcriptions with increased TNF-α production. The current case-control study aimed at detecting the frequency of TNF-α -308G/A gene polymorphism as genetic markers in Egyptian children with ITP, and to clear out their possible role in choosing the treatment protocols of therapy, using PCR restriction fragment length polymorphism assay. Ninety-two ITP patients and 100 age and sex-matched healthy controls were recruited in the study. The results obtained revealed that the frequency of TNF-α -308A/A homotype in ITP patients was significantly higher than that of the controls, and conferred almost six-fold increased risk of ITP acquisition. The polymorphic A allele frequency was significantly higher in ITP patients than in the controls, conferring almost two-fold increased ITP risk. In conclusion, our study suggests the possibility that TNF-α -308 gene polymorphism may contribute to the susceptibility of childhood ITP in Egyptian children.

Tumor necrosis factor-alpha single nucleotide polymorphisms in juvenile systemic lupus erythematosus

BACKGROUND

Juvenile systemic lupus erythematosus (JSLE) is a multi-system autoimmune disorder of unknown origin. Given the importance of the contribution of pro-inflammatory cytokines, including tumor necrosis factor-alpha (TNF-α), towards the pathogenesis of JSLE, this study was performed to assess TNFA gene polymorphisms in a case-control study.

METHODS

Fifty nine patients with JSLE were enrolled in this study as case group and compared with healthy control subjects. The frequency of alleles, genotypes, and haplotypes of TNFA single-nucleotide polymorphisms (SNPs) at positions -308 and -238 were evaluated, using polymerase chain reaction with sequence-specific primers method.

RESULTS

The G allele at position -238 in TNFA promoter region was significantly more frequent in patients with JSLE than in the healthy controls (P value<0.001), while the frequency of A allele at the same position was significantly lower than controls. Furthermore, a significant positive association for G/G genotype at the same position was detected in patients' group compared with control subjects (P value<0.001). The GA haplotype of TNFA (positions -308, -238) was significantly less frequent in case group than in controls (P value<0.001), while GG was the most frequent haplotype for TNFA in the patient group, compared to controls (P value<0.01).

CONCLUSIONS

Pro-inflammatory cytokine gene polymorphisms may influence susceptibility to JSLE. Particular TNFA gene variants are associated with JSLE and could be used as a genetic marker for susceptibility to JSLE.

TNF-308 G/A polymorphism and risk of systemic lupus erythematosus in the Polish population

OBJECTIVES

Numerous studies have been performed with TNF-α-308 G/A (rs1800629) single nuclear polymorphism (SNP) to evaluate the risk of SLE in various ethnicities. However, the significance of TNF-α-308 G/A in both clinical and laboratory studies of the disease remains unclear.

METHODS

Using a high-resolution melting curve analysis, we assessed the prevalence of TNF-α-308 G/A SNP in SLE patients (n = 262) and controls (n = 528) in a Polish population. We also assessed the contribution of this SNP to various clinical symptoms and the presence of autoantibodies in SLE patients.

RESULTS

The p-value obtained using a χ(2) test for the trend of TNF-α-308 G/A was statistically significant (ptrend = 0.0297). However, using logistic regression analysis for the presence of the HLA-DRB1*03:01 haplotype, we observed that the TNF-α-308 G/A SNP may be the DRB1*03:01-dependent risk factor of SLE in the Polish population. There was a significant contribution of TNF-α-308 A/A and A/G genotypes to arthritis OR = [2.692 (1.503-4.822, p = 0.0007, pcorr = 0.0119)] as well as renal SLE manifestation OR = [2.632 (1.575-4.397, p = 0.0002, pcorr = 0.0034)]. There was a significant association between TNF-α-308 A/A and A/G genotypes and the presence of anti-Ro antibodies (Ab) OR = 3.375(1.711-6.658, p = 0.0003, pcorr = 0.0051). However, the logistic regression analysis revealed that only renal manifestations and the presence of anti-anti-Ro antibodies remained significant after adjustment to the presence of the HLA-DRB1*03:01 haplotype.

CONCLUSION

Our studies indicate that the TNF-α-308 G/A polymorphism may be a DRB1*03:01 haplotype-dependent genetic risk factor for SLE. However, this SNP was independently associated with renal manifestations and production of anti-Ro Ab.

Th1 and Th2 polymorphisms in Sjögren's syndrome and rheumatoid arthritis

BACKGROUND

Sjogren's syndrome is characterized by T-cell infiltration of exocrine glands leading to parenchymal destruction and impaired glandular function. This process is orchestrated by cytokines, whose secretion can be regulated by genetic polymorphisms.

MATERIALS AND METHODS

The aim of this study was to investigate the influence of interleukin-6 -174G/C, interleukin-10 -1082G/A, tumor necrosis factor-α -308G/A, interferon-γ +874A/T gene polymorphisms in (RA) and secondary Sjögren's syndrome (sSS). A study sample that comprised of 138 Brazilian patients was divided into three groups: RA (n = 66), sSS (n = 20), and healthy controls - C (n = 52). Patients were subjected to Schirmer's test, unstimulated salivary flow rate, biopsy of minor salivary glands, and serological tests for diagnosing SS. Genomic DNA was obtained from saliva samples and submitted to genotyping. The association between genotypes/alelle frequency and SS susceptibility was tested, as well as their association with clinical features of SS.

RESULTS

Tumor necrosis factorα (TNFα)-308GA polymorphisms differed significantly between AR, SS, and C patients (P = 0.008). IL-6 overall G carriers and TNFα A carriers had a higher risk of presenting SS (P = 0.021). IL-6 polymorphism distribution was also distinctive regarding lymphocytic infiltration at the minor salivary glands (P = 0.026) and Schirmer's test (P = 0.035).

CONCLUSION

These results suggest that IL-6 -174GC and TNFα-308GA gene polymorphisms are associated with susceptibility to SS. Additionally, IL-6 polymorphism could influence lymphocytic infiltration of salivary glands and diminish lachrymal gland function.

Tumour necrosis factor alpha (TNF-α) genetic polymorphisms and the risk of autoimmune liver disease: a meta-analysis

Epidemiological studies have evaluated the association between tumour necrosis factor alpha (TNF-α)- 308G/A and (TNF-α)- 238G/A polymorphisms, and the risk of autoimmune liver disease (AILD), yet the results are conflicting. To derive a more precise estimation of the relationship, we performed this meta-analysis. A systematic review was conducted to identify all eligible studies of TNF-α polymorphisms and AILD risk. We used odds ratios (ORs) with 95% confidence intervals (CIs) to assess the strength of the association between the two TNF-α polymorphisms and AILD risk. A total of 15 eligible studies were identified. Overall, positive associations of -308G/A polymorphism with AILD risk were found (A vs G allele: OR =1.45, 95%CI = 1.13- 1.86; AA vs GG: OR = 2.74, 95%CI = 1.51- 4.96; GA vs GG: OR = 1.46, 95%CI = 1.11- 1.92;dominant model: OR = 1.57, 95%CI = 1.18- 2.10; recessive model: OR = 2.22, 95%CI = 1.31- 3.76). In subgroup analysis by ethnicity, a significantly higher risk was found in Caucasians. In subgroup analysis by AILD category, significant association was observed in autoimmune hepatitis and primary sclerosing cholangitis, especially in Caucasians. Patients carrying TNF-α-238A allele had a slightly decreased risk of developing AILD (OR = 0.65, 95%CI = 0.48- 0.87). However, we found both TNF-α polymorphisms were not associated with primary biliary cirrhosis risk, even in subgroup analysis. Our meta-analysis suggests that the TNF-α-308G/A and -238G/A polymorphisms may contribute to AILD susceptibility in Caucasians,especially for autoimmune hepatitis and primary sclerosing cholangitis. Nevertheless, we found both TNF-α polymorphisms were unlikely to be associated with the risk of primary biliary cirrhosis

Association between TNF promoter -308 G>A and LTA 252 A>G polymorphisms and systemic lupus erythematosus

Tumor necrosis factor (TNF) and lymphotoxin alpha (LTA) are pivotal cytokines in the pathogenesis of systemic lupus erythematosus (SLE). To investigate the possible association of the polymorphism of the TNF promoter gene -308 and that of the LTA gene 252 with susceptibility to SLE and with phenotypic disease features in Egyptian patients. A case control study involving 100 SLE patients and 100 unrelated healthy controls. Polymerase chain reaction and restriction fragment length polymorphism methods were applied to detect genetic polymorphism. We found that TNF-308 genotype AA was significantly increase by 26 % in SLE patients compared to 10 % in the control group (p = 0.003; OR 3.16; CI 1.43-6.98) and the frequency of the A allele of the TNF promoter -308 was significantly higher in the SLE patients (42 %) than in the control subjects (24 %) (p < 0.001; OR 2.29; 95 % CI 1.49-3.52). Genotype LTA 252 GG showed a significant increase by 22 % in SLE patients compared to 6 % in the control group (p = 0.001; OR 4.42; 95 % CI 1.71-11.44), and the frequency of the G allele of the LTA was significantly higher in the SLE patients (38 %) than in the control subjects (21 %) (p < 0.001; OR 2.31; 95 % CI 1.48-3.6). Genotype (AA+GA) of TNF was significantly associated with clinical manifestations as malar rash, arthritis, oral ulcers, serositis and systemic lupus erythematosus disease activity index. Genotype (GG+GA) of LTA was significantly associated with arthritis. These results suggest that TNF and LTA genetic polymorphisms contribute to SLE susceptibility in the Egyptian population and are associated with disease characteristics. TNF-308 and LTA+252 polymorphic markers may be used for early diagnosis of SLE and early prediction of clinical manifestations, like arthritis.

Polymorphism of inflammatory genes and arsenic methylation capacity are associated with urothelial carcinoma

Chronic exposure to arsenic can generate reactive oxidative species, which can induce certain proinflammatory cytokines such as tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6) and interleukin-8 (IL-8). TNF-α, IL-6 and IL-8 have been shown to be involved in the development and progression of various cancers, including bladder cancer. This study aimed to investigate the joint effect of the polymorphism of TNF-α -308 G/A, IL-6 -174 G/C, IL-8 -251 T/A and urinary arsenic profiles on urothelial carcinoma (UC) risk. This study evaluated 300 pathologically-confirmed cases of UC and 594 cancer-free controls. Urinary arsenic species were detected using high-performance liquid chromatography-linked hydride generator and atomic absorption spectrometry. The polymorphism of TNF-α -308 G/A, IL-6 -174 G/C and IL-8 -251 T/A was determined using polymerase chain reaction-restriction fragment length polymorphism. The joint effects on UC risk were estimated by odds ratios and 95% confidence intervals using unconditional logistic regression. We found that the TNF-α -308 A/A and IL-8 -251 T/T polymorphisms were significantly associated with UC. Moreover, significant dose-response joint effect of TNF-α -308 A/A or IL-8 -251 T/T genotypes and arsenic methylation indices were seen to affect UC risk. The present results also showed a significant increase in UC risk in subjects with the IL-8 -251 T/T genotype for each SD increase in urinary total arsenic and MMA%. In contrast, a significant decrease in UC risk was found in subjects who carried the IL-8 -251 T/T genotype for each SD increase in DMA%.

Tumor necrosis factor alpha promoter polymorphism -308 G/A in Brazilian patients with systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by the production of antibodies to components of the cell nucleus in association with a diverse array of clinical manifestations. Polymorphisms in cytokines genes may play an important role in the development and clinical manifestation. Due to this, there is a great interest in the identification of biomarkers that which could quantify the susceptibility and disease activity. A case-control study of 98 lupus cases and 76 lupus-free adults controls, was performed to analyze whether or not the polymorphism of the TNF-α gene promoter at positions -308 G/A would alter the risk for SLE and clinical manifestations. Genotyping was carried out by polymerase chain reaction, PCR products were digested by NcoI restriction enzyme and fractionated after on 2% Agarose gel and visualized posteriorly staining by ethidium bromide. There were significant differences in the distribution of the TNF-α gene polymorphism between the SLE and control groups. Individual carriers of the variant allele A had a 3.29 (95% CI: 1.7738-6.1325)-fold increased risk for SLE. Moreover, association was observed between SLE patients and serositis (P=0.0228). This study presents a preliminary evidence of association between TNF-α polymorphism and SLE susceptibility in the Northeast population from Brazil.

Association of discoid lupus erythematosus with clinical manifestations and damage accrual in a multiethnic lupus cohort

OBJECTIVE

To determine the clinical manifestations and disease damage associated with discoid rash in a large multiethnic systemic lupus erythematosus (SLE) cohort.

METHODS

SLE patients (per American College of Rheumatology [ACR] criteria) ages ≥16 years with a disease duration of ≤10 years at enrollment and defined ethnicity (African American, Hispanic, or white) from a longitudinal cohort were studied. Socioeconomic-demographic features, clinical manifestations, and disease damage (per the Systemic Lupus International Collaborating Clinics/ACR Damage Index) were determined. The association of discoid lupus erythematosus (DLE) with clinical manifestations and disease damage was examined using multivariable logistic regression.

RESULTS

A total of 2,228 SLE patients were studied. The mean ± SD age at diagnosis was 34.3 ± 12.8 years and the mean ± SD disease duration was 7.9 ± 6.0 years; 91.8% were women. DLE was observed in 393 patients with SLE (17.6%). In the multivariable analysis, patients with DLE were more likely to be smokers and of African American ethnicity and to have malar rash, photosensitivity, oral ulcers, leukopenia, and vasculitis. DLE patients were less likely to be of Hispanic (from Texas) ethnicity and to have arthritis, end-stage renal disease, and antinuclear, anti-double-stranded DNA, and antiphospholipid antibodies. Patients with DLE had more damage accrual, particularly chronic seizures, scarring alopecia, scarring of the skin, and skin ulcers.

CONCLUSION

In this cohort of SLE patients, DLE was associated with several clinical features, including serious manifestations such as vasculitis and chronic seizures.

The role of Tumor Necrosis Factor-alpha (TNF-α) in the pathogenesis of systemic lupus erythematosus

The Tumor Necrosis Factor-alpha (TNF-α) is a pleiotropic cytokine that produces different stimuli in various physiological and pathological conditions. TNF-α contributes importantly to the development of T cells, B cells, and dendritic cells. However, TNF-α is also a potent inflammatory mediator and apoptosis inducer. The significance of the TNF-α involvement in the pathogenesis of systemic lupus erythematosus (SLE) remains controversial. From the genetic standpoint, a number of studies suggest that the TNF-α gene polymorphism is involved in the susceptibility of SLE. Moreover, there is a close association between the TNF-α gene expression and clinical manifestations. In addition, the increased serum level of TNF-α is observed in SLE patients and associated with disease activity and certain systemic manifestations. Treatment with anti-TNF agents is, however, controversial in SLE since induction of antinuclear antibodies, anti-dsDNA, anticardiolipin antibodies, and cases of drug-induced lupus have been observed in rheumatoid arthritis patients. In this context, this study reviewed the importance of TNF-α in the pathogenesis of SLE.

Association of TNF-α promoter-308 A/G polymorphism with susceptibility to systemic lupus erythematosus: a meta-analysis

Published data on the association between tumor necrosis factor-alpha (TNF-α) promoter-308 A/G polymorphism and systemic lupus erythematosus (SLE) risk are inconclusive. To derive a more precise estimation of the relationship, a meta-analysis was performed. A total of 28 studies including 2,992 cases and 4,326 controls (5,924 cases and 8,484 controls in A versus G comparison) were involved in this meta-analysis. Meta-analysis was performed for genotypes A/A (recessive effect), A/A+A/G (dominant effect), and A allele in fixed or random effects models. In addition, we also performed a "model-free" analysis by considering the G/G genotype as the reference and estimated the OR for the A/A versus G/G and A/G versus G/G genotype. Overall, an association of TNF-α promoter-308 A/G polymorphism with SLE was found (A versus G: OR = 1.686, 95% CI = 1.400-2.032, P < 0.001; A/A versus A/G+G/G: OR = 3.043, 95% CI = 2.185-4.238, P < 0.001; A/A+A/G versus G/G: OR = 1.822, 95% CI = 1.379-2.407, P < 0.001; A/A versus G/G: OR = 3.686, 95% CI = 2.628-5.172, P < 0.001; A/G versus G/G: OR = 1.691, 95% CI = 1.291-2.215, P < 0.001). However, stratification by ethnicity indicated that the risk A allele was not associated with SLE in Asian (A versus G: OR = 1.207, 95% CI = 0.856-1.702, P = 0.283) and African population (A versus G: OR = 1.225, 95% CI = 0.597-2.516, P = 0.580). In summary, this meta-analysis indicated that TNF-α promoter-308-A/G polymorphism is associated with susceptibility to SLE.

IL-10 and TNFalpha genotypes in SLE

The production of two regulators of the inflammatory response, interleukin 10 (IL-10) and tumor necrosis factor α (TNFα), has been found to be deeply deregulated in SLE patients, suggesting that these cytokines may be involved in the pathogenesis of the disease. Genetic polymorphisms at the promoter regions of IL-10 and TNFα genes have been associated with different constitutive and induced cytokine production. Given that individual steady-state levels of these molecules may deviate an initial immune response towards different forms of lymphocyte activation, functional genetic variants in their promoters could influence the development of SLE. The present review summarizes the information previously reported about the involvement of IL-10 and TNFα genetic variants on SLE appearance, clinical phenotype, and outcome. We show that, in spite of the heterogeneity of the populations studied, the existing knowledge points towards a relevant role of IL-10 and TNFα genotypes in SLE.