Allele frequencies of polymorphisms of TNFA, IL-6, IL-10 and IFNG in an Italian Caucasian population.

Polymorphisms in the regulatory and intronic regions of several cytokines have been associated with differential cytokine production. In this paper we genotyped, using the polymerase chain reaction-sequence-specific primers (PCR-SSP) method, a series of 363 healthy Italian Caucasians with the aim of obtaining a reference population for further studies on the role of cytokines in the inflammatory and immune responses. We also compared the results to those for other populations. The polymorphisms analysed were those of tumour necrosis factor alpha (TNFA), interleukin 6 (IL-6), interleukin 10 (IL-10) and interferon gamma (IFNG). We found that the frequency of allele TNFA*1 at position -380 was 87.7% and that of TNFA*2 was 12.4%, significantly different from those of the UK and Japanese populations but not different from that of a population in Gambia. For IL-10 the frequencies of alleles -1082A and -1082G were 63.0% and 37.0% and those of alleles -819C, - 819T, -592C and -592A were 70.8, 29.2, 70.8 and 29.2%, respectively, significantly different from those observed in south-east England, in Manchester and in an Oriental population from southern China. The frequencies of IL-6 alleles - 174C and -174G were 29.0 and 71.0%, respectively; for IFNG polymorphisms at position -874, in the population under evaluation, the alleles -874T and -874A were present in 44.7 and 55.3% of the subjects, respectively. Genotype frequencies of IL-6 were significantly different from those observed in populations from Germany and from the UK. The analysis carried out by our group indicates that there is heterogeneity in the frequencies of the cytokine polymorphisms among the different Caucasian populations, and this underlines the importance of a 'local' reference population when evaluating the clinical relevance of cytokine gene polymorphisms.     

Distribution of cytokine gene polymorphisms in Thai population

The distribution of 21 cytokine polymorphisms within 13 cytokine and cytokine receptor genes was analyzed in 102 healthy Thai individuals using the LIFECODES Cytokine SNP Typing kit. The TGFB codon25 marker is monomorphic in the Thai population. The IL1B+3962, IL6-174, and TNFA-238 are very rare polymorphisms, with only 0.01-0.04 minor allele frequency (MAF). The IL4-1098, IL1A-889, and IL10-1082 are found only 0.06-0.08 in Thai. Other cytokine polymorphisms (IL1B-511, IL1R pst1 1970, IL1RN mspa1 11100, IL4RA+1902, IL12B-1188, IFNG+874, TGFB codon10, TNFA-308, IL2-330, IL2+166, IL4-590, IL4-33, IL10-819, and IL10-592) in Thai have MAFs more than 0.10, ranging between 0.13 and 0.47. When comparing the allele and genotype frequencies with public single nucleotide polymorphism (SNP) database, most cytokine polymorphisms in Thai show similar distribution to Han Chinese and Japanese, but significantly different from Caucasian and African populations. Only a few markers, including IL4A+1902, TNFA-308, IL1B+3962, and IL2+166 show statistically different distribution among Thai and other Asian populations especially with the Japanese.     

Allele frequencies of polymorphisms of the tumour necrosis factor‐α, interleukin‐10, interferon‐γ and interleukin‐2 genes in a North European Caucasoid group from the UK

Cytokine gene polymorphisms affecting cytokine production may influence rejection and graft‐versus‐host disease following solid organ and haemopoietic stem cell (HSC) transplantation, respectively. Polymorphisms in the regulatory regions of several cytokine genes have been described; for example, tumour necrosis factor‐α (TNF‐α) has a G/A substitution at position ?308, interleukin‐2 (IL‐2) has a T/G substitution at position ?330 and interleukin‐10 (IL‐10) has substitutions at positions ?1082(G/A), ?819(C/T) and ?592(C/A). Microsatellites associated with cytokine production have been detected in the first intron of the IFN‐γ gene and flanking the TNF‐α gene. In this study, we have genotyped a single panel of healthy Northern European Caucasoids living in the south‐east of England for the above‐mentioned polymorphisms and compared the results to those published for other populations. A PCR method using sequence‐specific primers (SSP) was developed for genotyping the IL‐2 polymorphism, and the ABI PRISM? 310 genetic analyser was used to detect the TNF‐α and IFN‐γ microsatellites. The allele frequencies of all the studied polymorphisms were consistent with those reported for other UK Caucasoid populations, but differences were observed when compared to other Oriental, African and Caucasoid groups. If these cytokine polymorphisms prove to have functional consequences, then any differences across population groups may have significant clinical relevance in disease and in the outcome of solid organ and HSC transplantation.     

TNF, IFNG, IL6, IL10 and TGFB1 gene polymorphisms in South and Southeast Brazil

This study attempted to establish single nucleotide polymorphism frequencies of TNF, IL6, IFNG, IL10 and TGFB1 genes among healthy individuals from South and Southeast Brazil. The sample included 108 healthy individuals from South and 106 from Southeast Brazil. Polymerase chain reaction using sequence-specific primers genotyping was performed for these gene cytokines with Cytokine Genotyping Primers (One Lambda, Canoga Park, CA, USA). Differences in genotypic and allelic frequencies between the populations were assessed by chi-square with either Yates' correction or Fisher's exact test. Our investigations showed that there were not any significant differences between these two Brazilian populations for these polymorphisms. A statistically significant difference in the distribution of alleles and genotypes for both IL6 and IL10 genes was observed between the Brazilian population and the African-derived populations. IL6-174GG genotype and allele G and IL10-819CT/-592CA genotypes are more frequent in African-derived populations than in this mixed Brazilian population, while IL10-1082GG genotype is more frequent in our population. This mixed Brazilian population is closer to those of Joinville's, Santa Catarina, and Rio de Janeiro's, Rio de Janeiro (RJ), Euro-Brazilian populations than to those of Salvador's, Bahia, and Rio de Janeiro's, RJ, African-Brazilian populations. These findings have an enormous importance for experimental design and empowering future linkage and association mapping studies of the role of cytokines in human diseases and allotransplantation outcome in Brazil.     

Cytokine gene polymorphism and Chlamydia trachomatis-specific immune responses

Chlamydia trachomatis-induced fallopian tube damage leading to tubal factor infertility (TFI) is linked with TNF, IL-10, and probably IFNG gene polymorphisms. The aim of this study was to clarify the contribution of these cytokine gene polymorphisms to interindividual variation in C trachomatis-specific immune responses and the cross-regulation of secreted cytokines and single nucleotide polymorphisms (SNPs). Cytokine polymorphisms (IL-10 -1082A/G, -819T/C, and -592A/C, IFNG +874T/A, and TNF -308G/A) were genotyped by polymerase chain reaction in 139 women. C trachomatis-specific immune responses were measured using lymphocyte proliferation (LP) induced by C trachomatis E and F strains and chlamydial heat shock protein 60 antigens. Cytokine secretion was measured in culture supernatants of infected and uninfected mononuclear leukocytes. IL-10 -1082/-819/-592 and IFNG +874 SNPs were associated with the intensity of LP responses to C trachomatis antigens. These cytokines also interact with each other and a cumulative effect of IL-10 -1082 and IFNG +874 genotypes was seen in LP responses to C trachomatis antigens. Our data suggest that interleukin-10 and interferon-γ regulate C trachomatis-specific immune responses in humans and that genetic variation in the expression of their coding genes explains interindividual variation in host immune responses to C trachomatis infection.     

Interleukin 10 gene promoter polymorphisms (rs1800896, rs1800871 and rs1800872) and haplotypes are associated with the activity of systemic lupus erythematosus and IL10 levels in an Iranian population

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease with unknown aetiology. According to the role of interleukin 10 (IL10) in SLE pathogenesis, the genetic alterations in its promoter region could be associated with elevated IL10 levels and exacerbated disease. Here, we investigated the association of genotype and haplotype frequencies of three IL10 gene promoter polymorphisms with susceptibility to SLE, IL10 plasma levels and disease activity of patients in an Iranian population. A total of 116 SLE patients and 131 healthy subjects were enrolled. The PCR‐RFLP technique was used to detect IL10 promoter genotypes at the positions of ?1082 (G/A), ?819 (C/T) and ?592 (C/A) in association with IL10 plasma levels and SLEDAI scores. The GG genotype of ?1082 polymorphism was associated with the increased risk of SLE [OR = 2.65, 95% CI (1.21–5.82), p‐value = 0.046]. The CC genotype in ?819 region was associated with SLE susceptibility [OR = 3.38, 95% CI (1.26–9.07), p‐value = 0.034] and C allele was introduced as risk allele [OR = 1.86, 95% CI (1.15–3.01), p‐value = 0.009] in this region. IL10 plasma levels were overexpressed in CC genotype carriers of ?592 SNP and decreased in AA genotype carriers of ?1082. IL10 was also increased in SLE patients with CGT (?592/?1082/?819) haplotype. The SLEDAI score was higher among CC genotype carriers at the position of ?592 and TT genotype carriers at the region of ?819. SLEDAI was also elevated among patients with CGC (?592/?1082/?819) and CAC (p = 0.011) haplotypes. The present study suggests that the IL10 –819(C/T), ?1082(G/A) and ?592(C/A) polymorphisms and the haplotypes are associated with SLE susceptibility, increased disease activity and elevated IL10 levels. While this is the first time to report such an association in an Iranian population, further studies are needed to confirm these findings.     

白细胞介素10基因启动子区多态性与乙型肝炎病毒感染预后的关联研究

目的探讨中国汉族人白细胞介素10基因(interleukin10gene,IL10)启动子区单核苷酸多态性与乙型肝炎病毒(hepatitisBvirus,HBV)感染、转归的关联。方法采用聚合酶链反应-限制性片段长度多态性分析方法,检测231例HBV感染者,165例HBV感染康复者和135名正常对照者IL10基因启动子-1082G/A、-819T/C、-592A/C位点基因型。结果IL10基因启动子-1082G/A、-819T/C、-592A/C位点基因型和等位基因在HBV感染组、HBV感染康复组和正常对照组之间的分布频率比较差异无统计学意义(P>0.05),在血清HBV-DNA<1×103拷贝/mL的HBV感染者组和HBV-DNA≥1×103拷贝/mL组之间的分布频率比较差异亦无统计学意义(P>0.05);但IL10基因启动子-819T/C和-592A/C位点基因型和等位基因在HBV无症状携带组和慢性乙型肝炎组之间的分布差异有统计学意义(P<0.05),-819T/C位点TT型和-592A/C位点AA型在慢性乙型肝炎组的频率明显较高。结论汉族人IL10基因启动子多态性可能与人群对HBV易感性及感染后的病毒血症水平无显著相关性;但IL10启动子-819T/C和-592A/C位点基因多态性与HBV感染后的肝脏炎症反应有关。     

Interleukin-10 Gene Polymorphisms in Recurrent Aphthous Stomatitis

Recurrent aphthous stomatitis (RAS) is a common oral inflammatory disease with unknown etiology in which the immune system seems to have a role in oral tolerance. Interleukin (IL)-10 is a cytokine synthesis inhibitory factor. Single nucleotide polymorphisms (SNPs) of IL10 gene could alter this cytokine production. The aim of this study was to investigate frequencies of IL10 alleles and genotypes in a group of individuals with RAS. Genomic DNA of 60 Iranian patients with RAS were typed for IL10 gene (C/A ?1082, C/T ?819, and C/A ?592), using PCR-SSP method. Frequency of each allele and genotype was compared to control group.

A significantly higher frequencies of the T allele at position ?819 (p?=?0.006) and the A allele at position of ?592 (p?<?0.001) were found in the patients with RAS group, when compared to the controls. IL10 GA genotype at position ?1082 (p?=?0.007), CA genotype at position ?592 (p?=?0.001), and CT genotype at position ?819 (p?=?0.001) were significantly higher in the RAS patients. The results of this study suggest that certain SNPs of IL10 gene have association with predisposition of individuals to RAS. However, further multicenter studies should be conducted to confirm the results of this study.     

Association of -592C/A, -819C/T and -1082A/G interleukin-10 promoter polymorphisms with idiopathic recurrent spontaneous abortion

Increasing evidence supports a role for altered T helper 1 (Th1)-Th2 cytokine balance in idiopathic recurrent spontaneous abortion (RSA). The aim of this study was to investigate the association of the interleukin 10 (IL-10) promoter polymorphisms -592C/A, -819C/T and -1082A/G with RSA. Women (n = 350) with at least three consecutive spontaneous abortions (RSA cases) and 200 control women with at least two successful pregnancies were included. The frequency of the -819T allele [P = 0.05, odds ratio (OR) = 1.51], but not other single-nucleotide polymorphisms (SNPs), was higher among RSA patients. Complete linkage disequilibrium (LD) was seen between -592C and -819C and -1082G alleles, as well as between -592A and -819T and between -819C and -1082G alleles only among patients. Although the genotype frequencies (except for -819C/C) of the three polymorphisms were comparable between patients and controls, higher frequency of -592A/-819T/-1082A haplotype (OR = 4.01, 95% CI = 1.83-7.95) was seen in cases versus controls. Regression analysis indicated that, after adjusting for potential variables, -592C/A (OR = 3.32, 95% CI = 1.76-6.27) and -819C/T (OR = 5.06, 95% CI = 2.59-9.91) were associated with exclusively early but not exclusively late RSA, where negative association for both was noted. This supports the notion of involvement of IL-10-592C/A and -819C/T polymorphisms as inherited risk factors of idiopathic RSA.     

中国汉族人群白细胞介素10启动子区基因多态性的等位基因频率

目的：了解中国汉族人群中白细胞介素10（IL-10）启动子区基因多态性的等位基因频率。方法：应用聚合酶链-限制性片段长度多态性分析（PCR—RFLP）技术,对131例健康中国汉族受检样本进行IL-10592、819、-1082三个位点的基因型检测。结果：IL-10-592位点A／A、C／A、C／C基因型频率分别为42．7％、36．6％、20．7％,IL-10 -819位点T／T、T／C、C／C基因型频率分别为42．7％、36．6％、20．7%;其相关等位基因频率与意大利高加索人及英国曼彻斯特人相比有显著性差异,但与韩国人之间的差异无统计学意义。结论：不同国家人群间存在IL-10启动子区基因多态性的差异。     

IL10 -1082, IL10 -819 and IL10 -592 polymorphisms are associated with chronic periodontitis in a Macedonian population

Genetic polymorphisms in the interleukin 10 (IL10) gene have been reported to influence the host response to microbial challenge by altering levels of cytokine expression. We analyzed nucleotide polymorphisms in the promoter region of the IL10 gene and its relation with periodontal disease in a Macedonian population. The study population consisted of 111 unrelated subjects with chronic periodontitis and 299 healthy controls. DNA was isolated and IL10 genotyping performed by PCR-SSP (Heidelberg kit) for the alleles and genotypes of IL10 -1082, IL10 -819 and IL10 -592. Frequencies of IL10 haplotypes and the haplotype zygotes were also examined. Comparisons between groups were tested using the Pearson's p-value. After Bonferroni adjustment, significant associations were detected between subjects with chronic periodontitis and IL10 genotypes (IL10 -1082/A:G was negative or protective and IL10 -1082/G:G was positive or susceptible). Cytokine polymorphism on the IL10 gene appears to be associated with susceptibility to chronic periodontitis in Macedonians.     

Lack of evidence of association between IFNG and IL28B polymorphisms and QuantiFERON-CMV test results in seropositive transplant patients

The aim of this study was to analyze the relationship between the IFNG?+874 T/A and IL28B (rs12979860) C/T polymorphisms and the secretion of IFNG by CD8+ T cells after stimulation with cytomegalovirus (CMV) peptides, measured using QuantiFERON-CMV (QF-CMV) assay. A total of 184 CMV-seropositive solid organ transplant patients (108 kidney, 68 liver and 8 lung) were recruited. Of them, 151 patients were QF-CMV Reactive (IFNG?≥?0.2?UI/mL) and 33 were Non-reactive. Genotype frequencies in the study population were TT (26.6%), AT (50.0%) and AA (23.4%) for IFNG?+874 and CC (52.7%), CT (39.1%) and TT (8.2%) for IL28B (rs12979860). These frequencies did not significantly differ between QF-CMV Reactive and Non-reactive patients. Nor were any significant differences observed in the quantitative IFNG level among the genotypes in either the IFNG or the IL28 genes. When we analyzed whether these polymorphisms had any impact on the risk of CMV replication after transplantation, the adjusted analysis showed no association. In summary, our results showed that IFNG?+874 T/A and IL28B (rs12979860) C/T polymorphisms are not associated with the IFNG response to CMV measured by the QuantiFERON-CMV assay, although these results should be confirmed with a higher number of patients.     

Pro‐ and anti‐inflammatory cytokine gene single‐nucleotide polymorphisms in inflammatory bowel disease

Anti‐inflammatory cytokines have an important role in disease, tumour and transplant processes. Alterations in the regulation of several cytokines have been implicated in a variety of inflammatory disorders, including IBD (inflammatory bowel disease) [Crohn′s disease (CD) and ulcerative colitis (UC)]. Cytokine polymorphisms are also known to affect the level of gene expression. Thus, the aim of this study was to determine the relationship between cytokine polymorphisms and the IBD pathologies in a Spanish population. Polymorphisms analysis was performed using PCR‐SSOP using a microbeads luminex assay. The following polymorphisms were determined: TNFα [?238G/A (rs361525) and ?308G/A (rs1800629)], IFNγ [+874A/T (rs62559044)], TGFβ [+869C/T (rs1982073) and +915G/C (rs1800471)], IL10 [?1082A/A (rs1800896), ?592A/C (rs1800872), ?819C/T (rs1800871)], IL6 [?174C/G (rs1800795)], IL12p40 [3′UTR ?1188A/C (rs3212227)], IL1α [?889C/T (rs1800587)], IL1β [?511C/T (rs1143634) and +3962C/T (rs1143633)], IL1R [Pst‐1 1970C/T] and IL1RA [Mspa‐1 11100C/T]. No statistical differences in TNFα, IFNγ, TGFβ, IL10, IL6, IL1α, IL1β, IL1R and IL1Ra genotypes and allele distributions between the IBD groups and healthy controls were found. However, we observed significant differences in the 3′UTR ?1188A/C polymorphism of IL12p40. So ?1188A allele was increased in patients with UC and the ?1188C allele (high IL12p40 production) was increased in patients with CD with respect to controls. These data are in concordance with the fact that CD has been shown to be associated with a Th1 T‐cell‐mediated inflammation model and high IL12/IFNγ production at histological affected sites. These data suggest that cytokine polymorphisms in TNFα, IFNγ, TGFβ, IL10, IL6 and IL1α, IL1β, IL1R and IL1Ra cytokine gene do not seem to be relevant in IBD susceptibility and IL12p40 3′UTR ?1188A/C polymorphism seems to be associated with a differential IBD development.     

Comparison of IL10 and IL2 genotypes of Turkish population with other populations

The human genome has been shaped by evolutionary and historical forces. Therefore, genetic polymorphisms are useful tools not only to understand the susceptibility to disease in modern populations, but the history of ancestral populations as well. For this purpose, data on genetic polymorphisms such as human leucocyte antigen, mitochondrial DNA sequence variability and the frequencies of TAP1 and TAP2 gene variants in Turkey have been reported previously. Here we have used interleukin (IL)‐10 (?592C/A, ?819T/C, ?1082G/A) and IL‐2 (?330T/G) as genetic markers to study the relationship between Turkish population and other populations.     

Association of cytokine genetic polymorphisms with the humoral immune response to recombinant vaccine against HBV in infants

The prevention of hepatitis B by vaccination is one the most efficient tools to avoid the transmission of the virus, although a considerable variability to the anti‐HBsAg antibody response has been described. Recently, polymorphisms of cytokine regulating genes have been described which seem to influence the immune response to various antigens. This article's objective was to evaluate the influence of cytokine genetic polymorphisms onto the humoral immune response to hepatitis B vaccine in infants. Vaccinated children were classified according to the level of anti‐HBsAg antibody titles. The genotyping for TNF (?308), TGFB1 (+869, +915), IL‐10 (?1082, ?819, ?592), IL‐6 (?174), and IFNG (+874) was accomplished by the PCR‐SSP technique. The TNF (?308) allele A presented a lower but not statistically significant frequency at 5% level in high responder patients (3.7% vs. 12.3%, P = 0.0919). The same was seen for the TNF (?308) genotype GA (7.4% vs. 24.5%, P = 0.0757). Further studies in other populations and evaluation of a greater number of individuals may contribute for a better understanding of the cytokine gene polymorphism influence in general and TNF polymorphism more specifically in the humoral immune response to the HBsAg vaccination in newborn children. J. Med. Virol. 82:929–933, 2010. © 2010 Wiley‐Liss, Inc.     

HLA class II polymorphisms and recurrent spontaneous abortion in a Southern Brazilian cohort

A high proportion of human recurrent spontaneous abortions (RSA) remain unexplained. The possible association between RSA and different genetic polymorphisms within the human leucocyte antigen system (HLA system, the human major histocompatibility complex) has been investigated with conflicting results since many decades. Here, we describe a case–control study with 136 Southern Brazilian women of predominantly European ancestry (75 control and 61 cases with unexplained RSA). We investigated the relationship between unexplained RSA and alleles and genotypes from two classical loci of the HLA: HLA‐DRB1 and HLA‐DQB1, as well as three loci related to cytokine production and their serum levels: TNFA (?308G>A), IL10 (?1082G>A, ?819T>C, ?592A>C) and IFNG (+874A>T). Genotyping was performed by an allele‐specific PCR method. While all results concerning cytokine‐related genes turned out to be negative, we found the genotype HLA‐DQB1*02:02, 03:01 to be significantly decreased and the allele HLA‐DRB1*11:04 to be significantly increased among patients.