Polimorfismos de la región promotora del gen de la IL-10 y artritis reumatoide en una población colombiana

Pro-inflammatory cytokine response pre-dominates immuno-genetic pathway in development of rheumatoid arthritis

Rheumatoid arthritis (RA) is a crucial inflammatory joint disease characterized by loss of self-tolerance and severe cartilage loss, autoimmune, and subchondral bone erosions. Cytokines are the key regulators of inflammatory responses. Homeostatic imbalances in pro- and anti-inflammatory cytokine activities can result in pathogenic inflammatory reactions. These imbalances could be initiated by environmental factors but the ability to define the threshold of environmental impact relies on the genetic background of the pro- and anti-inflammatory cytokines. To address this a case-control association study was carried out in 429 individuals from Malayalam speaking ethnic population from South India. Functionally relevant SNPs from IL-10, IL-6, IL-1β and IL-1RN were genotyped using PCR -RFLP and sequencing. Meta-analysis was performed for the associated variants of IL-10, IL-1β. Significant association with RA was observed with IL-1β rs1143634, rs1143627, IL-10 rs1800896, IL-6 rs1800796, rs1800797. The associated SNPs are likely to impact transcriptional activity of a gene. Meta-analysis with global populations also provide evidence that IL-10 and IL-1β could be a global marker for RA. The functional significance of associated risk variants of IL-1β and IL-6 indicate increased production of the pro-inflammatory cytokines while IL-10 risk allele suggest reduced production of anti- inflammatory cytokines. The study concludes that increased production of pro-inflammatory cytokines and reduced production of anti- inflammatory cytokines may influence the Th1/Th2 equilibrium resulting in a triggering of Th1 mediated inflammatory responses in development of RA.

Interleukin10-1082 A/G polymorphism: Allele frequency, correlation with disease markers, messenger RNA and serum levels in North Indian rheumatoid arthritis patients

BACKGROUND

Rheumatoid arthritis (RA) is an autoimmune inflammatory disorder of unknown etiology. IL-10 stimulates B cell survival and is involved in antibody isotype switching. The serum IL-10 levels are increased in RA patients. Ethnicity influences polymorphisms in cytokine genes. Therefore, this study was designed to explore possible association, if any, between polymorphism of IL10-1082 A/G, serum cytokine levels, inflammatory markers and gene expression in RA patients of North India.

METHODOLOGY

A total of 187 RA patients classified according to American college of rheumatology 2010 criteria and 214 controls were included in the study. Levels of serum IL-10 and inflammatory markers were estimated by ELISA. PCR-RFLP was used to analyze IL10-1082 A/G polymorphism. Quantitative real time PCR was used to measure the mRNA expression of IL-10 gene.

RESULTS

The serum inflammatory markers were significantly higher in RA patients. Circulating IL-10 levels were positively and significantly correlated with RF (r = 0.28), anti-CCP (r = 0.26), CRP (r = 0.17) and mRNA expression levels (r = 0.59) among RA patients. Homozygous mutant variant (GG) and heterozygous mutant variant (AG) were associated with patients of RA (OR = 2.87 and 1.55, p < 0.05) as compared to controls. The association still persisted when the heterozygous and homozygous mutants (AG + GG) were clubbed together (OR = 1.67, p < 0.05). The mRNA expression of IL-10 was found to be 3.63 folds higher (housekeeping gene, β-actin) and 2.42 folds higher (housekeeping gene, 18S rRNA) in RA patients as compared to controls.

CONCLUSION

The results indicate that IL10-1082 A/G polymorphism is associated with genetic susceptibility/predisposition to RA in North Indian population.

Association of interleukin-10 gene single nucleotide polymorphisms with rheumatoid arthritis in a Chinese population

PURPOSE OF THE STUDY

Increasing numbers of studies show that interleukin (IL)-10 plays a key role in the pathogenesis of autoimmune diseases including rheumatoid arthritis (RA) and acts as an immunomodulatory cytokine. The purpose of the present study was to analyse the relationship between gene single nucleotide polymorphisms (SNPs) in the IL-10 gene and RA susceptibility.

STUDY DESIGN

We genotyped three SNPs (rs1800890, rs3024495, rs3024505) of the IL-10 gene in a Chinese population of 354 RA patients and 367 controls. Genotyping was conducted using TaqMan SNP genotyping assays. Plasma IL-10 levels were measured by ELISA.

RESULTS

The A allele of the rs1800890 variant was significantly related to decreased risk for RA compared with the T allele (A vs T: OR 0.580, 95% CI 0.345 to 0.975, P=0.038). No significant association between the genotype distribution of these SNPs and RA susceptibility was detected. The genotype effect of the dominant model was also evaluated, but no statistical difference was found. Further analysis in RA patients demonstrated that none of these SNPs were associated with rheumatoid factor (RF) or anti-citrullinated protein antibody (anti-CCP). In addition, no significant differences in plasma IL-10 levels were observed among RA patients with different genotypes.

CONCLUSIONS

The IL-10 rs1800890 variant might contribute to RA susceptibility in the Chinese population. Replication studies in different ethnic groups are required to further examine the critical role of IL-10 gene variation in the pathogenesis of RA.

Associations between interleukin-10 polymorphisms and susceptibility to rheumatoid arthritis: a meta-analysis

The aim of this study was to determine whether the interleukin-10 (IL-10) polymorphisms confer susceptibility to rheumatoid arthritis (RA). A meta-analysis was conducted on the associations between the IL-10 -1082 G/A, -592 C/A, -892 C/T and IL-10.R polymorphisms and RA using; (1) allele contrast, (2) the recessive model, (3) the dominant model, and (4) the additive model. A total of 16 studies (19 comparisons) involving 2647 RA patients and 3383 controls were considered in the meta-analysis. Meta-analysis of the IL-10 -1082 G/A polymorphism showed no association with RA in the study subjects, or in European or Asian subjects. However, meta-analysis of the -1082 G allele in 4 studies in Hardy-Weinberg equilibrium showed a significant association with RA (OR=1.217, 95% CI=1.027-1.442, P=0.0236). In contrast, meta-analysis of the C allele, the CC genotype, and of the CC versus the AA genotype of the IL-10 -592 C/A polymorphism showed significant associations with RA. The overall ORs of the associations between the C allele and RA were 0.684 and 0.758 (95% CI=0.494-0.946, P=0.022; 95% CI=0.475-1.210, P=0.045) in all study subjects and Asians. Meta-analysis of the CC+CT versus TT genotype and of the CC versus TT genotype of the IL-10 -892 C/T polymorphism revealed significant associations with RA. The overall OR of the association between the C allele carrier and RA was 0.552 (95% CI=0.375-0.812, P=0.003). No association was found between the IL10.R2 alleles and RA. This meta-analysis suggests that the IL-10 -592 C/A polymorphism confers susceptibility to RA in Asians and that the IL-10 -1082 G/A and -892 C/T polymorphisms are associated with RA susceptibility. These findings suggest the IL-10 genes confer susceptibility to RA.

Genetic susceptibility to different clinical forms of tuberculosis in the Peruvian population

Racial variation, twin studies, segregation analyses, linkage and association studies all suggest that genetic factors play an important role in predisposition to tuberculosis. Many previous studies have been performed with pulmonary TB patients, as the most prevalent form of clinical TB (nearly 95%), and very few of them have considered extrapulmonary TB. The present study evaluates the effects of variation in eight candidate genes (LTA, TNF, IL1B, IL1RN, IL10, TGFB1, TIRAP and P2X7) with pulmonary, pleural, miliary and other extrapulmonary forms of TB in a Peruvian population from the North of Lima. 626 TB cases and 513 healthy controls were enrolled in this study. LTA(+368) and IL10(-592) were associated with different clinical forms of TB (P<0.05). LTA(+368) genotype A/A was protective for pleural TB, LTA(+368) G/A was correlated with susceptibility to miliary TB. Genotypes A/A and G/A were associated with protection and susceptibility respectively when considering all extrapulmonary TB forms versus either healthy controls or pulmonary TB patients. Carriers of IL10(-592)*C were under-represented among those with pulmonary TB and all TB forms (P<0.001). IL10(-1082)-IL10(-592) haplotypes showed different distributions among patients with pulmonary TB and all TB forms (P<0.01) when compared to healthy controls. In addition, IL10(-1082)-IL10(-592) haplotypes showed differences between pleural, miliary and all forms of extrapulmonary TB when compared with pulmonary TB (P<0.05). All findings are consistent with an under-representation of the IL10(-1082)*A-IL10(-592)*A haplotype in pulmonary TB patients. These results suggest that the polymorphisms LTA(+368) and IL10(-592), or variants in strong linkage disequilibrium, variably affect susceptibility to the differing clinical forms of TB in Peruvians.

Interleukin 10 and tumor necrosis factor-alpha genotypes in rheumatoid arthritis--association with clinical response to glucocorticoids

OBJECTIVE

There are dysregulated levels of interleukin 10 (IL-10) and tumor necrosis factor-alpha (TNF-alpha) in rheumatoid arthritis (RA), and their role in the disease is controversial. We analyzed the association of functional polymorphisms of IL-10 and TNF-alpha with susceptibility and disease characteristics at the time of diagnosis, and we also evaluated their possible use as predictors of clinical response to treatments.

METHODS

Patients with recent-onset RA (n = 162) and healthy controls (n = 373) were genotyped for -1082 IL-10 and -308 TNF-alpha polymorphisms and data were related to clinical and immunological measurements of patients at the time of diagnosis. Response to treatment after 6 months was determined in 125 patients by the absolute change in Disease Activity Score (DAS28) and the American College of Rheumatology criteria for improvement.

RESULTS

We found a reduced frequency of the low IL-10 producer genotype (-1082AA) in patients with RA compared to controls (26.5% vs 38.9%; p = 0.006), while it is a risk factor for anticyclic citrullinated peptide antibodies (anti-CCP) positivity (p = 0.028). Evaluation of clinical response to treatments indicated that carriage of the high IL-10 genotype was associated with a favorable outcome (p = 0.009), specifically to prednisone therapy (p = 0.0003). No significant effects were observed with TNF-alpha polymorphism alone; however, in combination with the IL-10 genotype, it increased the strength of these associations.

CONCLUSION

Results show an association between the low IL-10 producer genotype and protection from RA; nevertheless, when other specific genetic and/or environmental factors trigger onset of RA, this genotype may predispose to development of anti-CCP+ RA disease with reduced response to prednisone treatment.

Association of polymorphisms in interleukin-10 gene promoter with autoantibody production in patients with rheumatoid arthritis

Interleukin-10 (IL-10) is a major anti-inflammatory cytokine that plays a crucial role in the regulation of the immune system. Allelic polymorphisms in the IL-10 gene promoter may contribute to the regulation of autoantibody production. To examine the association between both individuals IL-10 single nucleotide polymorphisms and the production of autoantibodies and the radiographic progression of rheumatoid arthritis (RA), a total of 144 RA patients were recruited into the study. We found significant differences in genotype distribution of the -1082G/A polymorphism between IgG, IgA, and IgM rheumatoid factor(RF)-positive/negative RA patients. We also found significant differences in allelic frequencies of the -3575T/A, -819C/T, and -592A/C polymorphisms between anticyclic citrullinated peptide (anti-CCP)-positive/negative RA patients. The haplotype TGAATA was found to be less frequent within anti-CCP-positive RA patients. Results obtained in this study provide evidence of an association between polymorphisms in IL-10 gene promoter and the production of autoantibodies in RA patients.

Association of tumor necrosis factor alpha and IL-10 promoter polymorphisms with rheumatoid arthritis in North Indian population

Rheumatoid arthritis is a chronic autoimmune disorder associated with altered expression of pro- and anti-inflammatory cytokines in the affected tissues. The aim of this study was to investigate the association between promoter polymorphisms of TNFalpha and IL-10 gene with susceptibility, age of disease onset and disease severity in North Indian patients with rheumatoid arthritis (RA). SNPs at position -308 and -863 of TNF gene and -819/-592 and -1082 position of IL-10 gene were determined in 222 patients and 208 healthy controls using RFLP or ARMS method. Polymorphism TNF -308A was less prevalent among the patients (1.7%) than controls (4.9%; p = 0.01, OR: 0.32, 95% CI: 0.13-0.76). Among female patients, IL-10 -592A allele associated with higher baseline disease activity scores (5.77 +/- 1.99) than -592C (5.57 +/- 1.19; p = 0.04). Female patients carrying allele A of TNFalpha -863 had earlier age of onset of RA (33.99 +/- 9.6 years) than those with allele C (36.15 +/- 11.21 years; p = 0.043). In conclusion, allele A at TNFalpha -308 locus provides protection against RA in North Indian population while another TNF allele A at -863 position had weak association with earlier onset of disease in female patients. On the other hand promoter polymorphisms of IL-10 did not affect susceptibility but polymorphism at -819/-592A was associated with higher disease activity scores at baseline.