Eotaxin gene single nucleotide polymorphisms in the promoter and exon regions are not associated with susceptibility to atopic dermatitis,but two of them in the promoter region are associated with serum IgE levels in patients with atopic dermatitis

Eotaxin is believed to play an important role in atopic dermatitis (AD) as a potent chemoattractant and activator of eosinophils and Th2 lymphocytes. The eotaxin gene is located at chromosome 17q21.1-q21.2, and linkage findings of AD on chromosome 17 were reported. Recently we have identified single nucleotide polymorphisms (SNPs) of eotaxin gene (-426C > T, -384A > G, 67G > A). To learn whether eotaxin gene SNPs are associated with susceptibility to AD or phenotypes of AD, we investigated the genotype frequencies at each SNP of the gene in AD patients and in controls. We examined 140 Japanese AD patients and 140 healthy Japanese individuals. Genotyping was performed using the polymerase chain reaction-restriction fragment length polymorphism method. No significant difference was observed in allele or genotype frequencies of any SNP between AD patients and controls. Serum immunoglobulin E (IgE) levels were significantly lower in CT and TT genotype than in CC (P = 0.038) in -426C > T SNP, and lower in GG than in AA and AG with borderline significance (P = 0.053) in -384A > G SNP in AD patients. Eotaxin gene SNPs in the promoter and exon regions are not associated with susceptibility to AD, but two of them in the promoter region are associated with phenotype of AD.     

Systematic linkage disequilibrium analysis of SLC12A8 at PSORS5 confirms a role in susceptibility to psoriasis vulgaris

The gene for solute carrier family 12 member A8 has recently been proposed as a candidate gene for psoriasis susceptibility (PSORS5) on chromosome 3q based on association of five single nucleotide polymorphisms (SNP) in Swedish patients. To investigate whether this locus is relevant for German psoriasis vulgaris (PsV) patients, we analyzed a group of 210 trios and a case-control group including 375 patients. Based on our investigation of the linkage disequilibrium (LD) structure of SLC12A8, we assayed 35 haplotype tag SNP and grouped them into nine LD-blocks. In the case-control study, we detected an association for six SNP and three LD-based haplotypes. Association was strongest for ss35527511 (chi2 = 11.224, p = 0.0008) and haplotype E-2 (chi2 = 11.788, p = 0.00059) and independent of the presence of an HLA-associated PSORS1 risk allele. Through extended haplotype analysis, we could show that two independent association signals exist in SLC12A8, suggesting allelic heterogeneity. None of the SNP showed association in trios, apart from a weak association of rs2228674 (transmission disequilibrium test statistics p = 0.048), probably due to insufficient power. We conclude that SLC12A8 is a susceptibility locus for PsV. In order to establish the exact nature of this association, efforts to identify the disease-causing variants are ongoing.     

Psoriasis is not associated with IL-12p70/IL-12p40 production and IL12B promoter polymorphism

Psoriasis is a type-1 T cell-mediated, chronic inflammatory disease. Since interleukin (IL)-12p70 promotes the development of type-1 T cells, we investigated whether psoriasis is associated with an increased production of this cyctokine by blood cells. Results revealed that the production of IL-12p70 by cells of psoriasis patients stimulated by 1 and 10 ng per mL, but not 100 ng per mL of lipopolysaccharide (LPS) was higher (p=0.03) than that by cells of healthy volunteers. The production of IL-12p40 by patients cells upon stimulation with 0.1 ng per mL LPS, but not higher concentrations, was higher (p=0.02) than that by cells of healthy volunteers. No association between IL-12p70 production by blood cells and the severity of psoriasis was observed, nor was there a difference in the LPS-stimulated production of this cytokine between cells of the early and late onset type of patients. The frequencies of the various genotypes for the promoter region of the gene encoding IL-12p40 (IL12B) did not differ between psoriasis patients and controls. No association was observed between the various IL12B promoter genotypes and the LPS-stimulated production of IL-12p70 or IL-12p40 by blood cells. Together, psoriasis is not associated with a promoter polymorphism in the IL12B gene nor with the production of IL-12p70 by LPS-stimulated blood cells.     

白介素12B基因rs6887695多态性与汉族人寻常性银屑病临床表型的相关性

目的 探讨白介素12B（IL-12B）基因多态性位点rs6887695与汉族人寻常性银屑病临床表型（发病年龄、家族史、临床类型、性别）的相关性。 方法　采用ABI Taqman探针荧光PCR技术,对575例寻常性银屑病患者和1403例健康对照的DNA样本进行IL-12B基因多态位点rs6887695的基因分型。使用SPSS14.0分析软件,χ2检验比较患者组和健康对照组间、不同临床表型组间的基因型和等位基因频率分布的差异性。 结果 IL-12B基因多态性位点rs6887695三种基因型（GG、GC、CC）频率在寻常性银屑病患者组分别为42.61%、45.39%和12.0%,健康对照组分别为34.42%、47.83%和17.75%;等位基因频率（G、C）患者组分别为65.30%和34.70%,健康对照组分别为58.34%和41.66%,基因型和等位基因频率分布在患者组和健康对照组间差异均有统计学意义（χ2值分别为16.31和16.54,P值均 < 0.01）,在慢性斑块状（543例）和急性滴状银屑病患者（32例）组间的差异均有统计学意义（χ2值分别为18.11和12.19,P值均 < 0.01）。等位基因G和基因型GG在患者组中的频率明显高于健康对照组,等位基因G和基因型GG在斑块状患者中的频率高于滴状患者。少儿发病组（35例）与成人发病组（540例）、家族史阳性组（102例）与家族史阴性组（440例）、男性患者组（341例）与女性患者组（234例）的基因型和等位基因频率分布差异均无统计学意义（P值均 > 0.05）。 结论 IL-12B（rs6887695）基因多态性与汉族人寻常性银屑病易感性相关联,特别是与斑块状银屑病相关,但与患者的发病年龄、家族史及性别可能无关联。     

Interleukin-13 gene polymorphism G4257A is associated with atopic dermatitis in Japanese patients

Interleukin (IL)-13 plays an important role in the induction of immunoglobulin E (IgE) and in the pathogenesis of atopic dermatitis (AD). We investigated the allele and genotype frequencies of three IL-13 single nucleotide polymorphisms (SNPs) (A704C and C1103T in the promoter region and G4257A in exon 4) in Japanese patients with AD. For A704C and C1103T SNPs, there were no significant differences in allele or genotype frequencies between AD patients and controls. For G4257A SNP, A allele was significantly increased in AD patients (39.5%) compared with controls (29.4%) (P = 0.016). The same proportion of each genotype and allele was observed in the patient subgroup with and without asthma. Serum IgE levels and peripheral eosinophil counts were not significantly different among genotypes in G4257A SNP. There was also no significant difference in allele or genotype frequencies between AD patients with mild disease and those with severe disease, between those with family history of AD and those without it, or between those with family history of atopic disorders and those without it. This result suggests that 4257A allele is associated with susceptibility to AD and that it may function in the pathogenesis of AD itself, presumably by other mechanisms than inducing IgE production.     

The -431C>T polymorphism of thymus and activation-regulated chemokine increases the promoter activity but is not associated with susceptibility to atopic dermatitis in Japanese patients

BACKGROUND: Thymus and activation-regulated chemokine (TARC) plays an important role in the pathogenesis of atopic dermatitis (AD). We recently detected the single nucleotide polymorphism (SNP) (-431C>T) in the 5'-flanking region of TARC gene. OBJECTIVES: To examine whether the -431C>T SNP of the TARC gene is associated with susceptibility to AD and whether it affects the promoter activity of the TARC gene. METHODS: We investigated the genotype and allele frequencies of the SNP in 193 AD patients and 158 healthy controls by polymerase chain reaction-restriction fragment length polymorphism method. We compared the promoter activities between TARC promoter carrying 431C and that carrying -431T by transient-transfection assay in DJM-1 cell line. RESULTS: There were no significant differences in genotype or allele frequencies between AD patients and controls (genotype: P = 0.38, allele: P = 0.22). Luciferase activity was higher in -431T constructs than in -431C constructs (2.3-fold, P = 9.5 x 10(-6)). CONCLUSION: These results suggest that the -431C>T SNP of the TARC gene enhances the promoter activity of TARC gene but is not associated with susceptibility to AD in Japanese population.     

Raf kinase inhibitor protein expression correlates with differentiation but not with ERK phosphorylation in cutaneous squamous cell carcinoma

BackgroundThe acute skin lesions of atopic dermatitis (AD) are associated with Th2 cells; however, the chronic skin lesions of AD are associated with Th1 cells via the action of IL-12.ObjectiveWe evaluated the associations of single nucleotide polymorphisms (SNPs) and haplotype in the IL-12 and IL-12 receptor genes, and determined the gene–gene interactions between the SNPs of these genes and the SNPs of the IL-18 gene that we previously reported.MethodWe genotyped 24 SNPs from 4 IL-12/IL-12R genes for 1089 case–control samples (631 AD patients and 458 normal controls). We measured the serum IL-12 concentrations in 89 individuals (79 AD patients and 10 controls) by ELISA. We analyzed the SNPs and haplotypes in each gene and also searched for the gene–gene interactions.ResultThe rs582504 (IVS ? 798A/T) SNP and the haplotype TA (rs582054 and rs2243151) in the IL-12A gene, and the rs438421 (IVS12 + 1266T/C) SNP and the haplotype CCA (rs375947, rs438421, and rs1870063) in the IL-12RB1 gene were significantly associated with the AD phenotype. We showed that the rs438421 polymorphism in the IL-12RB1 (TT) gene and the rs2066446 polymorphism in the IL-12RB2 (AA) gene had a significant interaction to develop the ADe phenotype (allergic type of AD), and those individuals with the risk alleles, TT/AA/CC (IL-12RB1/IL-12RB2/IL-18), have more than a 10-fold increased risk to develop ADe.ConclusionThis study provides evidence for a significant interaction between the IL-12RB1 and IL-12RB2 genes that contribute to a 4-fold increased risk for developing ADe. In addition to the IL-12R interaction, we suggest that the IL-18 gene can significantly interact with the IL-12R gene to develop ADe. In addition to the interaction, the SNPs and haplotypes in the IL-12A and IL-12RB1 genes are independently and significantly associated with the AD phenotype, and especially with the ADe phenotype. This data may contribute to our understanding of AD genetic interactions and account for the additional risk of certain patients to develop AD.     

关节病型银屑病与强直性脊柱炎易感基因关联研究

目的：对关节病型银屑病与强直性脊柱炎的易感基因进行关联分析,以期发现共同的易感基因。方法：以379例关节病型银屑病（PsA）、595例寻常型银屑病（PsV）及806例健康对照为样本,以Sequenom MassARRAY 系统为平台,对全基因组关联研究发现的强直性脊柱炎的9个易感基因SNP位点进行基因分型和数据分析。结果：ERAP1基因（rs27037,P=6.66×10-5,OR：1.43）、21q22.2（rs2242944,P =1.07×10-3, OR：0.73）及IL23R基因（rs1004819,P=4.58×10-3,OR：1.28）与PsA相关。ERAP1（ rs27037, P=1.56×10-4,OR：1.35）与PsV相关。ERAP1基因对于PsA和PsV的患病风险无差异。IL23R基因(rs1004819)及21q22.2（rs2242944）在PsA和PsV患病风险上存在中等程度的异质性（I2值分别为57.41和71.20）,但P值无明显差异（小于0.05）。 IL23R基因（rs11209032,p=1.57×10-3,OR:1.52）与PsA脊柱炎相关。结论：ERAP1基因、21q22.2区域及IL23R基因是PsA与强直性脊柱炎共有的易感基因。     

儿童特应性皮炎IL-18基因启动子多态性与相关性研究

目的 检测儿童特应性皮炎患者外周血DNA中IL-18基因第2外显子上游启动子1第137和第607位点多态性，探讨其与儿童特应性皮炎发病的相关性。方法 从82例重庆汉族儿童特应性皮炎患者及健康对照组100例的抗凝血中提取DNA，用序列特异性引物PCR扩增技术（PCR-SSP）及PCR产物直接测序法鉴定基因类型，对结果进行统计学分析处理。结果 IL-18基因第2外显子的第137位点核苷酸存在G、C二态性，可表现为GG纯合、CC纯合、GC杂合三种基因型；第607位点核苷酸存在C、A二态性，可表现为CC纯合、AA纯合、CA杂合三种基因型。IL-18-137G/C基因型分布在患者组和对照组间差异有统计学意义，患者组137C等位基因频率显著高于对照组（χ2 = 4.54，P = 0.033），137C等位基因在重度组中分布频率显著高于轻度组（χ2 = 3.93，P < 0.05）；IL-18-607位点等位基因频率在轻度、中度、重度组及对照组之间分布差异无统计学意义（P > 0.05）；IL-18-137G/C位点C等位基因在病例与对照组比较，优势比OR = 1.76，137G/C基因型的优势比OR = 2.33。结论 儿童IL-18基因第2外显子上游启动子1第137和第607位点存在单核苷酸多态性，IL-18-137G/C是特应性皮炎患儿的候选易感基因。     

No association of cytokine gene polymorphisms in Chinese patients with atopic dermatitis

BACKGROUND: Atopic dermatitis (AD) is a common chronically relapsing skin disease associated with the activation of T-helper 2 cells. Recent studies have shown that polymorphisms in the genes for interleukin (IL)-4, the IL-4 receptor, IL-13, and signal transducer and activator 6 (STAT6) may contribute to susceptibility of AD. To date, no cytokine gene polymorphism study has been conducted on Chinese patients with AD. AIMS: To determine whether genetic polymorphisms of the cytokine genes might influence the development of AD. METHODS: DNA samples were obtained from 94 patients and 186 control subjects. Using direct sequencing and microsatellite genotyping, we examined 22 polymorphisms in eight cytokine genes including the genes for IL-4, -10, -12B and -13, the IL-4 receptor, tumour necrosis factor (TNF)-alpha, STAT6, and interferon (IFN)-gamma. RESULTS: No significantly different allelic and genotypic distributions of the cytokine gene polymorphisms could be found between patients and controls. Moreover, no association was observed with disease onset, gender, the presence of elevated serum total IgE level or blood eosinophilia. CONCLUSION: Our study suggests that the analysed genetic polymorphisms of cytokine genes do not appear to be associated with AD susceptibility in our Chinese population.     

Association of IL-12B gene rs6887695 polymorphism with hereditary susceptibility and clinical characterization of psoriasis vulgaris in the Chinese Han population

We aimed to investigate the role of IL-12B gene polymorphism (rs6887695) in the disease susceptibility and clinical phenotypes of psoriasis vulgaris patients in the Chinese Han population. The genotype data of the IL-12B gene polymorphism (rs6887695) in 575 psoriasis patients and 1,403 normal controls were investigated using TaqMan technology. The Chi-square test was used to compare the genotype and allele frequency distribution among the groups. The genotypic and allelic frequencies of rs6887695 in the IL-12B gene between the cases and controls, as well as between the guttate and plaque psoriasis cases, were statistically significant (P _genotype <0.01, P _allele <0.01). However, the differences between the pediatric and adult onset psoriasis patients, between familial and sporadic cases, and between female and male cases were not statistically significant (P > 0.05). The genetic polymorphism of the IL-12B gene (rs6887695) may be associated with the psoriasis susceptibility in the Chinese Han population, especially for the plaque cases, but not associated with the age at onset, family history, or sex.     

IL-12B和IL-23R基因多态性与中国汉族人银屑病易感性关联研究

目的 探讨中国汉族人群中IL-12B和IL-23R基因多态性与银屑病易感性的关系。方法 在217例银屑病患者和288例正常人对照中,采用DNA直接测序法对IL-12B和IL-23R基因的多态性位点进行基因分型,并将阳性结果在一个更大的包括578例银屑病患者和1422例正常人对照的整合样本群中,使用Taqman探针荧光PCR技术进行重复检验。实验数据进行Hardy-Weinberg平衡检验、卡方检验、单倍型分析和Logistic回归模型分析。结果 IL-12B rs6887695位点等位基因频率在病例组与对照组之间差异有统计学意义,OR = 1.33（95% CI 1.03 ~ 1.73）,P = 0.028;IL-23R rs11465817和rs1343152位点等位基因频率在病例组与对照组之间差异无统计学意义（P > 0.05）。连锁不平衡分析发现,rs11465817和rs1343152位点之间有一定的连锁不平衡（D′ = 0.744,r2 = 0.281）。对2个位点进行单倍型分析发现,A-A ∶ OR = 2.890,P = 0.0018,提示这一单倍型具有显著的发病风险。结论 IL-12B基因rs6887695多态性与中国汉族人群银屑病易感性相关;IL-23R基因rs11465817、IL-23R基因rs1343152位点多态性与中国汉族人群银屑病易感性无显著相关性,但是,IL-23R基因rs11465817-rs1343152位点A-A单倍型的中国汉族人具有更高的银屑病发病风险。     

Macrophage-derived chemokine (MDC)/CCL22 produced by monocyte derived dendritic cells reflects the disease activity in patients with atopic dermatitis

BACKGROUNDS: Atopic dermatitis (AD) is a recurrent inflammatory skin disease characterized by high serum levels of IgE and Th2-type cytokines such as IL-4, IL-5 or IL-13. Chemokines attract leukocytes in inflamed tissues. We have previously found that thymus and activation regulated chemokine (TARC)/CCL17 and macrophage-derived chemokine (MDC)/CCL22 are highly secreted in the plasma levels of AD patients. Dendritic cells (DCs) are antigen-presenting cells that are divided into two subgroups including monocyte derived DCs (MoDCs) and plasmacytoid DCs (pDCs). OBJECTIVES: The aim of the study was to elucidate CCL17 and CCL22 production by MoDCs in AD patients, psoriasis vulgaris (PsV) patients and healthy controls (HC). METHODS: MoDCs were obtained from AD patients, PsV patients or HC and were cultured. In addition, the chemokine levels were measured in the supernatants. RESULTS: We found that the CCL22 levels produced by MoDCs in AD patients to be significantly higher than those of PsV patients and HC. There was a significant correlation between the CCL22 levels produced by MoDCs and the SCORAD index. No significant difference in the CCL17 levels produced by MoDCs was detected among AD patients, PsV patients or HC. Immunosuppressive drugs such as dexamethasone (Dex), tacrolimus and cyclosporine (Cys) inhibited the CCL22 production by MoDCs in the AD patients. CONCLUSION: These data suggest that the CCL22 level produced by MoDCs thus reflects the disease activity of AD and it may also play an important role regarding the production of CCL22 in the pathogenesis of AD.     

IL-33和IL1RL1基因单核苷酸多态性与特应性皮炎相关性研究

目的：分析IL-33和IL1RL1基因单核苷酸多态性(SNPs)与特应性皮炎（AD）的相关性。方法：PCR-SSP方法检测89例AD患者和138名正常对照组受试者IL-33和IL1RL1编码基因的等位基因和基因型频率。结果：AD患者的IL-33 rs1800925 C等位基因的频率高于对照组，而T等位基因和rs764706552等位基因G低于对照组（均P＜0.001）。IL-33 rs1800925基因型CC和rs764706552基因型CG与AD显著正相关（均P＜0.001）。两组患者的IL1RL1基因的等位基因和基因型频率无明显差异（均P＞0.05）。结论：IL-33基因可能与AD的发病相关。     

Alteration in the production of IL-10 and IL-12 and aberrant expression of CD23, CD83 and CD86 by monocytes or monocyte-derived dendritic cells from atopic dermatitis patients

Atopic dermatitis (AD) is characterized by the presence of Th2-type cells in the skin infiltration as well as in the peripheral blood, although a predominant infiltration of interferon-gamma (IFN-gamma)-producing cells is also reported in the chronic skin lesions of AD. Recently it has become clear that the development of Th1 or Th2 is strongly influenced by factors produced by the antigen presenting cells (APCs). To clarify whether APCs from AD patients play a favorable role in the differentiation of Th2 cells, we compared the production of cytokines and the expression of co-stimulatory molecules by monocytes (MOs) and monocyte-derived DCs (MoDCs) after stimulations with various reagents between 13 AD patients and 13 age-matched healthy controls. We examined their production of IL-1 beta, IL-10, IL-12p40, and IL-12p70, and their expression of CD23, CD40, CD54, CD80, CD83, CD86 and HLA-DR. We stimulated them with superantigens, lipopolysaccharide (LPS), agonistic anti-CD40 antibody, phytohemagglutinins (PHA), IL-1beta/TNF-alpha, IL-4, or IFN-gamma. The following results were obtained (1): IL-10 production was significantly enhanced in AD MOs after LPS stimulation. In contrast, IL-12p40 production was significantly lower in AD MOs than in HC MOs after a variety of stimulations (2). IL-12p40 was also significantly lower in AD MoDCs after LPS stimulation (3). The induction of CD23 with IL-4 was significantly higher in AD MOs. and finally (4), AD MoDCs augmented the expression of CD83, CD86, and HLA-DR less significantly than HC MoDCs after anti-CD40 Ab stimulation. These data indicate that AD APCs show some responses different from those observed in HC APCs after several stimulations, such as LPS, IL-1 beta/TNF-alpha, IL-4, or anti-CD40 Ab, and that these responses might play a role in the polarizing process of helper T cells into Th2 cells as recognized in AD patients.     

Genome-wide meta-analysis of psoriatic arthritis identifies susceptibility locus at REL

Psoriatic arthritis (PsA) is a chronic inflammatory musculoskeletal disease affecting up to 30% of psoriasis vulgaris (PsV) cases and approximately 0.25 to 1% of the general population. To identify common susceptibility loci, we performed a meta-analysis of three imputed genome-wide association studies (GWAS) on psoriasis, stratified for PsA. A total of 1,160,703 single-nucleotide polymorphisms (SNPs) were analyzed in the discovery set consisting of 535 PsA cases and 3,432 controls from Germany, the United States, and Canada. We followed up two SNPs in 1,931 PsA cases and 6,785 controls comprising six independent replication panels from Germany, Estonia, the United States, and Canada. In the combined analysis, a genome-wide significant association was detected at 2p16 near the REL locus encoding c-Rel (rs13017599, P=1.18 × 10(-8), odds ratio (OR)=1.27, 95% confidence interval (CI)=1.18-1.35). The rs13017599 polymorphism is known to associate with rheumatoid arthritis (RA), and another SNP near REL (rs702873) was recently implicated in PsV susceptibility. However, conditional analysis indicated that rs13017599, rather than rs702873, accounts for the PsA association at REL. We hypothesize that c-Rel, as a member of the Rel/NF-κB family, is associated with PsA in the context of disease pathways that involve other identified PsA and PsV susceptibility genes including TNIP1, TNFAIP3, and NFκBIA.     

Polymorphisms of vitamin D receptor gene in Japanese patients with psoriasis vulgaris

We examined polymorphisms of vitamin D receptor (VDR) gene in Japanese patients with psoriasis vulgaris (PsV). We also studied the association between VDR gene polymorphisms and the response to vitamin D (VD) topical treatment in psoriatic patients. FokI, BsmI, ApaI and TaqI genotypes were determined by restriction fragment patterns in patients (n = 115) and controls (n = 69). In addition, 54 psoriatic patients were divided into two groups in terms of their response to VD (tacalcitol) topical treatment: non-responsive (n = 30) and responsive (n = 24) patients. The frequencies of B allele and t allele were lower in patients than in controls (9 vs. 19%: p < 0.01, 7 vs. 14%: p < 0.05, respectively). In regard to response to VD treatment, F allele was lower in non-responsive patients than in controls (47 vs. 64%, p < 0.05). We show that polymorphisms of VDR gene are associated with Japanese patients with PsV. Allelic variance in the VDR gene or other genes in linkage disequilibrium with this gene might predispose to the development of PsV.     

Genetic variants of the IL-23R pathway: association with psoriatic arthritis and psoriasis vulgaris, but no specific risk factor for arthritis

Variants in two genes of the IL-23 receptor (R) pathway have recently been shown to be associated with psoriasis vulgaris (PV). We were interested whether the risk conferred by these variants differs between psoriatic skin and joint disease. Four variants of the IL12B and IL23R genes were analyzed in 1,114 PV patients, 748 patients with psoriatic arthritis (PA) and 937 healthy controls before and after stratification for the major psoriasis risk allele at psoriasis susceptibility locus 1 (PSORS1). For both PA and PV, we detected the strongest association with two IL12B single-nucleotide polymorphisms and the corresponding haplotype as reflected by minimal P-values of 10(-7) and highest odds ratios of 1.50 (1.28-1.75) for rs6887695 in PA patients and 1.50 (1.27-1.76) for rs3212227 in the PV cohort, respectively. For IL23R, only rs11209026 showed an association. The results remained significant after correction for multiple testing. No difference was observed after stratification for the PSORS1 risk allele. While confirming recent reports on variants of the IL-23R pathway as susceptibility factors for PV, our study is the first to extend analysis of both genes to PA. However, our results indicate that these variants are not specific risk factors for arthritis, but relevant for susceptibility to psoriasis in general.     

Interleukin 4 receptor alpha chain polymorphism Gln551Arg is associated with adult atopic dermatitis in Japan

Localization of a locus for atopy to chromosome 16p12-p11 and reported associations of Ile50Val and Gln551Arg polymorphisms in interleukin-4 receptor alpha chain (IL 4R gene) with atopy prompted us to sequence the gene in 27 adult atopic dermatitis (AD) and 29 non-atopic (non-AD) subjects. Among six known polymorphisms, Gln551Arg was significantly associated with AD (P = 0.01). This polymorphism was found to be heterozygous in six of 27 patients with AD but none of the 28 non-AD controls. Ile50Val, which was previously reported to be associated with atopic asthma in Japan, showed no association with AD in our group. Glu375Ala and Cys406Arg also showed no association with AD. The IL 4R gene should thus be considered a compelling candidate gene for AD.