The association of -627 interleukin-10 promoter polymorphism in Chinese patients with systemic lupus erythematosus

rs1800890 Polymorphism of IL-10 and Susceptibility to Idiopathic Thrombocytopenic Purpura

Immune thrombocytopenic purpura (ITP) is an immune bleeding disorder that is reported in approximately 2 out of every 100,000 adults with a mean age of 50 years. Several factors such as various genetic backgrounds are associated with the pathogenesis of ITP. Interleukin (IL)-10 is a complicated cytokine that has a role in tumor progression, antitumor immunity, and immune system regulation. rs1800890 is an IL-10 single nucleotide polymorphism linked to lower levels of IL-10. A total of 67 patients with ITP and 70 healthy individuals (controls) were considered in this study. The IL-10 polymorphism was detected by the amplification refractory mutation system-polymerase chain reaction technique. According to our analysis, individual carriers of the AA genotype were less likely to develop ITP. The AT genotype was more common in patients with ITP in comparison to the control group. However, there was no significant association between rs1800890 genotypes ( p  = 0.775, odds ratio =1.517, 95%) in the acute and chronic groups. We observed that women had a higher mean frequency of this polymorphism ( p  = 0.0012). The rs1800890 AA genotype was associated with the highest platelet counts. However, the mean platelet volume and platelet distribution width values among alleles of the polymorphisms did not vary significantly. The IL-10 rs1800890 polymorphism may have a role in idiopathic thrombocytopenic purpura etiology. As a result, more research with a larger number of sample sizes is suggested.

Genetic polymorphisms of interleukin 6 and interleukin 10 in Egyptian patients with systemic lupus eythematosus

Systemic lupus erythematosus (SLE) is a complex autoimmune disease. Cytokine gene polymorphisms play an important role in SLE. Thus, this study aimed to investigate the associations between interleukin 6 (IL-6) and interleukin 10 (IL-10) promoter single-nucleotide polymorphisms (SNPs) and their susceptibility to SLE and the implications for plasma levels. We genotyped IL-6-174G/C (rs1800795) using mutagenically separated polymerase chain reaction (MS-PCR) and IL-10-1082G/A (rs1800896) and -819C/T (rs1800871) using sequence specific primer polymerase chain reaction (SSP-PCR) in 100 Egyptian patients and 119 controls. The plasma levels of IL-6 and IL-10 were measured by enzyme-linked immunosorbent assay (ELISA). There was significant increase in the frequency of IL-6 (-174) GG genotype ( P < 0.05) and G allele ( P < 0.01) compared to controls. A significant increase in the distribution of IL-10 (-1082G/A) GG ( P < 0.05) and AA ( P < 0.05) genotypes and a significant reduction in the frequency of GA genotype ( P < 0.05) was found in SLE patients. The mean serum concentration of IL-6 ( P < 0.001) and IL-10 ( P < 0.001) was significantly elevated in SLE patients compared to healthy controls. There was no  significant association of the most common clinical findings and IL-6 and IL-10 gene polymorphisms in SLE patients. In conclusion, our preliminary study indicated that both GG genotype and G allele of IL-6 (-174G/C) could be considered as risk factors for SLE. In addition, the polymorphisms at IL-10 (-1082 G/G and AA) may play a role in SLE susceptibility in Egyptian patients. Larger prospective studies are needed to confirm our findings.

Role of interleukin-10 and interleukin-10 receptor in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a prototypic autoimmune disease characterized by excessive production of a variety of autoantibodies, accumulation of immune complexes, and multiple organ systems involvement. Interleukin-10 (IL-10) has an important role in the growth, survival, differentiation, and function of B cells. Abnormally increased IL-10 synthesis seems contributing to the spontaneous hyperactivity of the B cell compartment, so that it can directly result in autoantibody production by committed plasma cells, circulating immune complexes formation, and eventually in tissue and organ damage, suggesting it might associate with the development of SLE. A better understanding of the regulation of IL-10 and its receptors (IL-10R) can likely provide more valuable clues to the pathogenic mechanisms underlying specific forms of SLE, so as to pave the way toward more effective therapeutics.

Associations between interleukin-10 polymorphisms and susceptibility to systemic lupus erythematosus: a meta-analysis

OBJECTIVE

The study determined whether interleukin-10 (IL-10) polymorphisms confer susceptibility to systemic lupus erythematosus (SLE).

METHODS

A meta-analysis was conducted on the associations between the IL-10-1082 G/A, -819 C/T, -592 C/A polymorphisms and the haplotype of the IL-10-1082 G/A, -819 C/T, -592 C/A polymorphisms and SLE.

RESULTS

A total of 19 studies involving 2828 SLE patients and 4008 controls were considered in the meta-analysis. Meta-analysis of the IL-10-1082 G/A polymorphism revealed an association between SLE and the IL-10-1082 G allele (odds ratio [OR] = 1.158, 95% confidence interval [CI] = 1.051-1.276, p = 0.003). Stratification by ethnicity indicated an association between the IL-10-1082 G allele and SLE in Europeans (OR=1.160, 95% CI = 1.039-1.296, p = 0.008). Meta-analysis stratified by ethnicity produced an association between the IL-10-819 C allele and SLE in Asians (OR = 1.308, 95% CI = 1.030-1.619, p = 0.027). Meta-analysis of the homozygous GCC/GCC haplotype failed to show a significant association with SLE in Europeans (OR = 1.223, 95% CI=0.981-1.526, p = 0.074). However, meta-analysis of the GCC haplotype revealed a significant association with RA in all study subjects (OR = 1.402, 95% CI = 1.001-1.964, p = 0.049). Stratification by ethnicity indicated an association between the GCC haplotype and SLE in Europeans (OR = 1.656, 95% CI = 1.087-2.523, p = 0.019), but not in Asians (OR = 1.100, 95% CI = 0.703-1.721, p = 0.677). Meta-analysis of homozygous ATA/ATA haplotype failed to show a significant association with SLE in overall and European groups. However, meta-analysis of the ATA haplotype revealed a significant association with SLE in all study subjects (OR = 1.516, 95% CI = 1.039-2.213, p = 0.031) and Asians (OR = 2.580, 95% CI = 2.086-3.192, p < 1 × 10(-9)), but not in Europeans (OR = 1.233, 95% CI = 0.816-1.862, p = 0.320).

CONCLUSIONS

This meta-analysis suggests that the IL-10 polymorphisms confer susceptibility to SLE in Europeans and in Asians.

Genetic risk factors of systemic lupus erythematosus in the Malaysian population: a minireview

SLE is an autoimmune disease that is not uncommon in Malaysia. In contrast to Malays and Indians, the Chinese seem to be most affected. SLE is characterized by deficiency of body's immune response that leads to production of autoantibodies and failure of immune complex clearance. This minireview attempts to summarize the association of several candidate genes with risk for SLE in the Malaysian population and discuss the genetic heterogeneity that exists locally in Asians and in comparison with SLE in Caucasians. Several groups of researchers have been actively investigating genes that are associated with SLE susceptibility in the Malaysian population by screening possible reported candidate genes across the SLE patients and healthy controls. These candidate genes include MHC genes and genes encoding complement components, TNF, FcγR, T-cell receptors, and interleukins. However, most of the polymorphisms investigated in these genes did not show significant associations with susceptibility to SLE in the Malaysian scenario, except for those occurring in MHC genes and genes coding for TNF-α, IL-1β, IL-1RN, and IL-6.

Monoclonal Antibodies for Systemic Lupus Erythematosus (SLE)

A number of monoclonal antibodies (mAb) are now under investigation in clinical trials to assess their potential role in Systemic Lupus Erythematosus (SLE). The most frequently used mAb is rituximab, which is directed against CD20, a membrane protein expressed on B lymphocytes. Uncontrolled trials reported an improvement of SLE activity in non-renal patients and other studies even reported an improvement of severe lupus nephritis unresponsive to conventional treatments. However two randomized trials failed to show the superiority of rituximab over conventional treatment in non renal SLE and in lupus nephritis. Preliminary trials reported promising results with epratuzumab, a humanized mAb directed against CD22, and with belimumab, a human mAb that specifically recognizes and inhibits the biological activity of BLyS a cytokine of the tumornecrosis-factor (TNF) ligand superfamily. Other clinical trials with mAb directed against TNF-alpha, interleukin-10 (Il-10), Il-6, CD154, CD40 ligand, IL-18 or complement component C5 are under way. At present, however, in spite of good results reported by some studies, no firm conclusion on the risk-benefit profile of these mAbs in patients with SLE can be drawn from the available studies.

Genetic variation in the interleukin-10 gene promoter in Polish patients with systemic lupus erythematosus

Identification of susceptibility genes in systemic lupus erythematosus (SLE) has recently become a topic of interest. The IL-10 promoter contains three single base-pair substitutions at -627C > A, -854C > T and -1117G > A. These single base-pair substitutions produce three different haplotypes, GCC, ACC and ATA, which affect IL-10 expression. We examined the distribution of -627C > A, -854C > T and -1117G > A IL-10 promoter polymorphisms in patients with SLE (n = 103, women only) and matched controls (n = 300). Despite the higher prevalence of the GCC/GCC, GCC/ATA and ATA/ATA genotypes in SLE patients than in controls, we observed that only GCC/GCC genotype frequency distribution was significant between these groups. We observed that women with the GCC/GCC genotype displayed an approximately twofold increased risk of SLE OR = 2.245 (95% CI = 1.354-3.721, P = 0.0022). We did not find any associations between various genotypes of IL-10 promoter haplotypes and clinical manifestations or autoantibody production in patients with SLE. Our observations indicate that the GCC/GCC promoter genotype may contribute to SLE incidence in Polish patients.