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

Interleukin 1α and 1β gene variations are associated with tuberculosis in silica exposed subjects

INTRODUCTION

Silicosis is a fibrotic lung disease resulting from the inhalation of crystalline silica and can be classified as simple or complicated according to the International Labour Organization criteria. Furthermore, individuals exposed to crystalline silica also have a higher risk for the development of tuberculosis (Tb). The contribution of inflammatory cytokines to the risk of silicosis and Tb in different populations has previously been reported. Since genetic background might be related to susceptibility to silicosis and Tb, the study of polymorphisms within IL-1α, IL-1β, and tumor necrosis factor protein-coding genes may contribute to elucidating the genetic basis of these diseases.

METHODS

Single nucleotide polymorphisms (SNPs) were genotyped by polymerase chain reaction using restriction fragment length polymorphism or by Taqman methodology, in a sample of 102 silica-exposed patients from Brazil.

RESULTS

No significant associations were observed between the SNPs studied and the severity of silicosis. However, significant associations were found between Tb and the C allele (odds ratio [OR] = 1.93, 95% confidence interval [CI], 1.01-3.73) and the CC genotype (OR = 2.34, 95% CI, 1.04-5.31) of IL1A -899C>T. The IL1B +3954C>T polymorphism also showed an association with Tb (T allele dominant model OR = 2.38, 95% CI, 1.04-5.41).

CONCLUSION

These preliminary results demonstrate that the IL1A and IL1B gene variations may contribute to some extent to susceptibility to Tb, but not silicosis. However, additional studies are still needed to confirm these results.

Th1, Th2, and Th17 cytokines in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by the breakdown of immune tolerance leading to excessive inflammation and tissue damage. Imbalance in the levels of cytokines represents one of the multifactorial causes of SLE pathogenesis and it contributes to disease severity. Deregulated levels of T helper type 1 (Th1), type 2 (Th2), and type 17 (Th17) cytokines have been associated with autoimmune inflammation. Growing evidence has shown deregulated levels of Th1, Th2, and Th17 cytokines in SLE patients compared to healthy controls associated with disease activity and severity. In this review, we describe and discuss the levels of Th1, Th2, and Th17 cytokines in SLE patients, and clinical trials involving Th1, Th2, and Th17 cytokines in SLE patients. In particular, with the exception of IL-2, IL-4, and TGF-β1, the levels of Th1, Th2, and Th17 cytokines are increased in SLE patients associated with disease severity. Current phase II or III studies involve therapeutic antibodies targeting IFN-α and type I IFN receptor, while low-dose IL-2 therapy is assessed in phase II clinical trials.

Malar rash is a predictor of subclinical airway inflammation in patients with systemic lupus erythematosus: a pilot study

BACKGROUND

Systemic lupus erythematosus (SLE) is a chronic, auto-immune, multi-organ disease that can affect both the skin and the lungs. Malar rash is a common skin manifestation of SLE and is linked to SLE disease activity, whereas lung involvement is a generally negative prognostic factor for these patients. However, a sensitive and non-invasive screening tool for potential lung involvement in SLE patients is still not available.

METHODS

This study aimed to investigate the relationship between malar rash and airway inflammation in adult SLE patients who were not known to have any lung involvement (clinical or radiologic). The study comprised of the measurement of the concentration of NO in exhaled breath or fraction of exhaled nitric oxide (FeNO) and levels were compared between those with and without malar rash. This tool is considered as a sensitive and non-invasive method that is routinely used in patients with asthma or other respiratory diseases to identify airway inflammation.

RESULTS

A total of 125 patients (100 females, 25 males) were enrolled during the study period from January 2011 to December 2014. Patients with malar rash (N = 35) had a significant decrease in serum levels of C4 (p < 0.05) compared to patients without malar rash (N = 90). The mean levels of FeNO in overall patients were 36.44 ± 8.87 ppb. A statistically significant difference in FeNO₅₀ values between patients with malar rash (43.46 ± 6.72 ppb) and without (29.43 ± 3.64 ppb) was found (p < 0.001). FeNO₅₀ values were inversely correlated only with serum C4 (p < 0.01). However, no correlation between FeNO₅₀ values and SLE clinical disease activity scores was found.

CONCLUSIONS

The presence of a malar rash may predict sub-clinical airway inflammation in SLE patients. Further prospective studies are needed to confirm the usefulness of FeNO measurements in monitoring SLE-associated airway inflammation.

Gene Polymorphisms and Serum Levels of Pro- and Anti-Inflammatory Markers in Dengue Viral Infections

Pro- and anti-inflammatory markers (tumor necrosis factor [TNF]-α, TNF-β, interferon [IFN]-γ, interleukin [IL]-6, IL-8, IL-10, and C-reactive protein [CRP]) were investigated in 80 patients infected with dengue viruses, 100 patients presenting with febrile illness but negative for dengue, and 99 healthy subjects. Immunoenzyme methods were used for quantitative assays in the plasma. Polymorphisms of TNF-α, TNF-β, IL-6, IL-8, and IL-10 genes were assessed by polymerase chain reaction (PCR)-restriction fragment length polymorphism and allele-specific oligonucleotide (ASO)-PCR for the IFN-γ. The highest mean serum levels of TNF-α, IFN-γ, IL-8, and CRP were observed in dengue-positive individuals. TNF-β, IL-6, and IL-10 levels were significantly higher in the dengue-negative individuals. No cytokine expression pattern was evidenced according to virus serotype. Genotypic frequency distributions were statistically significant for the polymorphisms of TNF-α and IFN-γ among positive, negative, and control dengue groups and IFN-γ among groups DENV-1, DENV-2, DENV-3, and controls. Modulation of cytokine expression and polymorphisms is a complex matter and needs further explanation considering the ethnic origins of the Brazilian population.

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.

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.

Association of lymphotoxin alpha polymorphism with systemic lupus erythematosus and rheumatoid arthritis: a meta-analysis

AIM

The aim of this study was to perform a meta-analysis of eligible studies to derive precise estimation of the associations of lymphotoxin alpha (LTA) 252 A>G polymorphism (rs909253) with systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA) risk.

METHOD

Data were collected from the following electronic databases, including EMBASE, PubMed and China National Knowledge Infrastructure (CNKI). A total of 19 studies (13 studies involving 1346 SLE patients and 1951 controls, six studies involving 1079 RA patients and 1057 controls) were included.

RESULTS

This meta-analysis showed no evidence of significant association of the A allele with SLE susceptibility (odds ratio [OR] 1.26; 95% confidence interval [CI] 0.98-1.62, P = 0.073), but it showed a weaker association under an additive model (OR 1.63, 95%CI 1.01-2.65, P = 0.047). Stratification by ethnicity indicated that the variant A allele carriers increased the risk of SLE in Asians (OR 1.91, 95%CI 1.44-2.53, P < 0.001). However, we failed to reveal any association between LTA gene 252 A>G polymorphism and RA risk under all models (for A vs. G: OR 1.02, 95%CI 0.79-1.33, P = 0.853; for AA + AG vs. GG: OR 0.86, 95%CI 0.52-1.41, P = 0.542; for AA vs. AG + GG: OR 1.19, 95%CI 0.80-1.78, P = 0.394, for AA vs. GG: OR 1.03, 95%CI 0.58-1.84, P = 0.919). Similar results were obtained in the subgroup analysis based on ethnicity.

CONCLUSION

The present study suggests that LTA 252 A>G polymorphism is associated with SLE susceptibility in Asians, and there is no significant association between LTA 252 A>G polymorphism and RA.

Meta-analysis of tumor necrosis factor alpha -308 polymorphism and knee osteoarthritis risk

Background

Several case–control studies have been conducted to clarify the association between the tumor necrosis factor alpha (TNF-α) -G308A polymorphism and risk of osteoarthritis (OA); however, the results are inconsistent. This meta-analysis was performed to clarify this issue using all the available evidence.

Methods

Eligible articles were retrieved by searching PubMed, Web of science and Google scholar. The strength of the association between the TNF-α -G308A polymorphism and risk of OA was assessed by odds ratios (ORs) with the corresponding 95% confidence interval (CI) for each study.

Results

Seven studies were included in the meta-analysis, which included 983 OA cases and 1355 controls. The pooled analysis based on all included studies showed a significantly increased OA risk in the recessive genetic model analysis (OR = 11.08, 95% CI = 4.75-25.86, p < 0.001) and in the A allele vs. G allele analysis (OR = 2.30, 95% CI = 1.08-4.90). However, there was no statistical difference in the dominant genetic model analysis (OR = 2.45, 95% CI = 0.95-6.27, p = 0.06). Furthermore, we found that OA patients had a higher frequency of the AA genotype (OR = 10.49, 95% CI = 4.47-24.61) and GA genotype (OR = 1.78, 95% CI = 1.03-3.08) compared with the control population.

Conclusion

Our results suggested that the TNF-α -G308A polymorphism were associated with an increased risk of OA.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2474-15-373) contains supplementary material, which is available to authorized users.