Are genetic variations in IL-21–IL-23R–IL-17A cytokine axis involved in a pathogenic pathway of rheumatoid arthritis? Bayesian hierarchical meta-analysis

Inflammatory cytokines have been established to be involved in the pathogenesis of rheumatoid arthritis (RA). The genetic polymorphisms in the interleukin (IL) 23 receptor (IL23R), IL21, and IL17 have been associated with RA risk. However, there is no conclusive understanding of the genes encoding the immunoinflammatory IL-21–IL-23R–IL-17A pathway in RA aetiopathogenesis. This meta-analysis was conducted to attain this goal. A comprehensive literature search was conducted in Scopus and PubMed to look for the relevant case–control studies up until 2018. A Bayesian hierarchical meta-analysis was carried out to assess the association between the polymorphisms and the risk of RA. The association was estimated by calculating the logarithm of odds ratio (Log OR) and 95% credible interval (95% CI). In this meta-analysis, 37 case–control studies comprising 23,506 RA patients and 25,984 healthy individuals were found for analyzing the IL23R, IL21, and IL1A gene polymorphism and risk of RA. In the IL23R gene rs1343151 SNP, the minor A allele significantly increased the risk of RA (Log OR = 0.085, 95% CI = 0.008, 0.156). Moreover, the minor AA genotype was significantly associated with increased RA risk (Log OR = 0.176, 95% CI = 0.028, 0.321). In addition, the C allele of the IL23R gene rs2201841 SNP significantly decreased the disease risk (Log OR = −0.544, 95% CI = −1.0, −0.065). Since Bayesian meta-analysis is a powerful strategy to pool the data, it can be mentioned that genetic polymorphisms of IL23R, but not IL21 and IL17A, are involved in susceptibility to RA.     

Association of a BTLA gene polymorphism with the risk of rheumatoid arthritis

Summary B and T lymphocyte attenuator (BTLA) is an immuno-inhibitory receptor with the ability to deliver inhibitory signal for suppressing lymphocyte activation. To test the potential association of the human BTLA gene with the development of rheumatoid arthritis (RA), a genetic case-control association study was conducted, by using a single nucleotide polymorphism (SNP), C+800T SNP, in the exon 5 of the human BTLA gene for genotyping 93 RA patients and 294 normal control individuals. The results showed that there is statistically significant difference in the genotype distributions between RA and control groups (p = 0.022). When compared with the heterozygous genotype (C/T genotype), the homozygous genotype (C/C or T/T genotype) appears to confer the increased risk of the RA susceptibility with the odds ratio of 1.88 (p = 0.015). These data indicate the significant association between the C+800T SNP in the BTLA gene with the RA susceptibility.     

MMP-2和TIMP-2基因启动子区多态性与卵巢上皮性癌关系的研究

为探讨MMP-2和TIMP-2基因启动子区单核苷酸多态性(SNPs)与卵巢上皮性癌发病风险的关系, 采用聚合酶链反应-限制性片段长度多态性(PCR-RFLP)方法检测了246例卵巢上皮性癌患者和324例对照妇女的MMP-2 C-1306T、C-735T和TIMP-2 G-418C 3个SNPs的基因型。结果显示, MMP-2 C-1306T SNP的等位基因及基因型频率分布在卵巢癌与对照组间无显著差异(P=0.55和P=0.42); 但卵巢癌组MMP-2 C-735T SNP的C等位基因和C/C基因型频率(80.7%和66.7%)明显高于对照组(75.5%和55.9%), 与T/T+C/T基因型比较, 携带C/C基因型可以显著增加卵巢癌的发病风险(OR=1.58, 95% CI=1.12~2.23), 进一步分层分析显示, C/C基因型主要与宫内膜样癌和年龄≥50岁妇女的发病风险显著相关, OR值分别为1.69(95%CI=1.03~2.79)和1.71(95% CI=1.14~2.57); 对MMP-2 C-1306T、C-735T 2个SNPs的单体型分析显示, 4种单体型频率(T_-1306-T_-735、T_-1306-C_-735、C_-1306-T_-735和C_-1306-C_-735)在两组间分布无显著差异(P=0.24); 虽然TIMP-2 G-418C SNP的等位基因及基因型频率在卵巢癌组与对照组间分布无显著性差异(P=0.33和P=0.47), 但以病理类型分层分析显示, 携带TIMP-2 G-418G/G基因型有增加宫内膜样癌发病风险的趋势(OR=1.62, 95%CI=0.94~2.78)。以上结果提示, MMP-2基因启动子区C-735T SNP的C/C基因型可能是卵巢上皮性癌发病的潜在危险因素, 而C-1306T SNP可能与卵巢上皮性癌的发病风险无关; TIMP-2 G-418C SNP可能与不同病理类型的卵巢上皮性癌发病风险有关。     

Association between single-nucleotide polymorphisms in selectin genes and immunoglobulin A nephropathy

Although intensive efforts have been undertaken to elucidate the genetic background of immunoglobulin A nephropathy (IgAN), genetic factors associated with the pathogenesis of this disease are still not well understood. We designed a case-control association study that was based on linkage disequilibrium among single-nucleotide polymorphisms (SNPs) in the selectin gene cluster on chromosome 1q24-25, and we found two SNPs in the E-selectin gene (SELE8 and SELE13) and six SNPs in the L-selectin gene (SELL1, SELL4, SELL5, SELL6, SELL10, and SELL11) that were significantly associated with IgAN in Japanese patients. All eight SNPs were in almost complete linkage disequilibrium. SELE8 and SELL10 caused amino acid substitutions from His to Tyr and from Pro to Ser (chi2=9.02, P=.0026, odds ratio = 2.73 [95% confidence interval [CI] 1.38--5.38] for His-to-Tyr substitutions; chi2=17.4, P=.000031, odds ratio = 3.61 [95% CI 1.91--6.83] for Pro-to-Ser substitutions), and SELL1 could affect promoter activity of the L-selectin gene (chi2=19.5, P=.000010, odds ratio = 3.77 [95% CI 2.02--7.05]). The TGT haplotype at these three loci was associated significantly with IgAN (chi2=18.67, P=.000016, odds ratio = 1.88 [95% CI 1.41--2.51]). Our results suggest that these eight SNPs in selectin genes may be useful for screening populations susceptible to the IgAN phenotype that involves interstitial infiltration.     

Analysis of the RNASEL gene in familial and sporadic prostate cancer

The RNASEL gene on chromosome 1q25 was recently identified as a candidate gene for hereditary prostate cancer (PC). To confirm these findings, we screened 326 patients from 163 families with familial PC for potential germline mutations, by use of conformation-sensitive gel electrophoresis, followed by direct sequence analysis. A total of six variants were identified, including one intronic and five exonic changes (three missense and two silent alterations). There were no unequivocal pathogenic changes. To further test for potential associations between genes and increased risk for disease, the three missense polymorphisms (Ile97Leu, Arg462Gln, and Glu541Asp) were genotyped in 438 patients with familial PC and in 510 population-based control subjects. Association testing revealed no significant differences between patients and control subjects for either the Leu97 variant (chi(2) trend test = 1.42; P=.23) or the Asp541 variant (chi2=1.52; P=.22). However, significant differences were detected for the Arg462Gln genotypes (chi2=5.20; P=.02; odds ratio [OR] = 0.54; 95% confidence interval [CI] 0.32-0.91) when the genotype Gln/Gln was compared with Arg/Arg. In subset analyses, associations were also observed in the younger group (age at diagnosis 相似文献   

Alleles distribution of polymorphic promoter region C-590T in interleukin-4 genes and Q-576r and Ile-50Val regions in IL-4 receptor gene IL-4RA in patients with HCV-infection

81 patients with confirmed HCV-infection and 48 healthy volunteers were examined. In healthy Caucasian participants living in Siberian region significant predominance of C/T genotype in promoter region C-590T of interleukin-4 (IL-4) gene and Q/Q and Ile/Val genotypes in points -50 and -576 of IL-4RA gene that codes alpha-chains of IL-4 receptor were revealed. In patients with HCV-infection predominance of C/T genotype in C-590T region in IL-4 gene (OR = 1.86), R/R genotype in Q-576R region of IL-4RA gene (OR=7.86), and Val/Val genotype in point Ile-50Val (OR = 2.6) of the same gene. Summary predictive coefficient of hepatitis C development in carriers of these genotypes approached to 95%. During analysis of role of allelic polymorphism of IL-4 genes in predisposition to hepatitis C development it is necessary to consider not only presence of allelic variants of promoter regions of the IL-4 genes, but also the polymorphism of genes coding molecules binding with this cytokine on target cells membranes and in its soluble form.     

Genetic variation in the base excision repair pathway and bladder cancer risk

Genetic polymorphisms in DNA repair genes may impact individual variation in DNA repair capacity and alter cancer risk. In order to examine the association of common genetic variation in the base-excision repair (BER) pathway with bladder cancer risk, we analyzed 43 single nucleotide polymorphisms (SNPs) in 12 BER genes (OGG1, MUTYH, APEX1, PARP1, PARP3, PARP4, XRCC1, POLB, POLD1, PCNA, LIG1, and LIG3). Using genotype data from 1,150 cases of urinary bladder transitional cell carcinomas and 1,149 controls from the Spanish Bladder Cancer Study we estimated odds ratios (ORs) and 95% confidence intervals (CIs) adjusting for age, gender, region and smoking status. SNPs in three genes showed significant associations with bladder cancer risk: the 8-oxoG DNA glycosylase gene (OGG1), the Poly (ADP-ribose) polymerase family member 1 (PARP1) and the major gap filling polymerase-β (POLB). Subjects who were heterozygous or homozygous variant for an OGG1 SNP in the promoter region (rs125701) had significantly decreased bladder cancer risk compared to common homozygous: OR (95%CI) 0.78 (0.63–0.96). Heterozygous or homozygous individuals for the functional SNP PARP1 rs1136410 (V762A) or for the intronic SNP POLB rs3136717 were at increased risk compared to those homozygous for the common alleles: 1.24 (1.02–1.51) and 1.30 (1.04–1.62), respectively. In summary, data from this large case-control study suggested bladder cancer risk associations with selected BER SNPs, which need to be confirmed in other study populations. Electronic Supplementary Material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Functional IL-23R rs10889677 Genetic Polymorphism and Risk of Multiple Solid Tumors: a Meta-Analysis

Interleukin-23 receptor (IL23R) can interact with IL-23 and, thus, is involved in the T-helper 17 (Th17) cell-mediated inflammatory process as well as tumorigenesis. Recently, a functional single nucleotide polymorphism (SNP) rs10889677 has been identified in the 3’-untranslated region of IL-23R. It has been showed that the rs10889677AC SNP could increase the binding affinity of microRNA let-7f and downregulate IL-23R expression. Several case-control studies have examined the association between this SNP and genetic susceptibility of multiple solid tumors. However, the conclusions are conflicting. Therefore, we conducted this meta-analysis to systematically study the role of this functional IL-23R SNP in development of multiple solid tumors. There are a total of 5 studies are eligible (6731 cases and 7296 healthy controls). Either fixed-effect model or random-effect model was used to calculate pooled odds ratios (ORs) and the 95% confidence interval (95% CI). Significant association between this functional rs10889677 genetic variant and risk of multiple solid tumors were observed (CC genotype vs. AA genotype: OR = 0.59, 95% CI = 0.53-0.66, P < 0.001). These findings demonstrated that the IL-23R rs10889677 genetic variant might play an important part during malignant transformation of multiple solid tumors.     

Replication of putative candidate-gene associations with rheumatoid arthritis in >4,000 samples from North America and Sweden: association of susceptibility with PTPN22, CTLA4, and PADI4

Candidate-gene association studies in rheumatoid arthritis (RA) have lead to encouraging yet apparently inconsistent results. One explanation for the inconsistency is insufficient power to detect modest effects in the context of a low prior probability of a true effect. To overcome this limitation, we selected alleles with an increased probability of a disease association, on the basis of a review of the literature on RA and other autoimmune diseases, and tested them for association with RA susceptibility in a sample collection powered to detect modest genetic effects. We tested 17 alleles from 14 genes in 2,370 RA cases and 1,757 controls from the North American Rheumatoid Arthritis Consortium (NARAC) and the Swedish Epidemiological Investigation of Rheumatoid Arthritis (EIRA) collections. We found strong evidence of an association of PTPN22 with the development of anti-citrulline antibody-positive RA (odds ratio [OR] 1.49; P=.00002), using previously untested EIRA samples. We provide support for an association of CTLA4 (CT60 allele, OR 1.23; P=.001) and PADI4 (PADI4_94, OR 1.24; P=.001) with the development of RA, but only in the NARAC cohort. The CTLA4 association is stronger in patients with RA from both cohorts who are seropositive for anti-citrulline antibodies (P=.0006). Exploration of our data set with clinically relevant subsets of RA reveals that PTPN22 is associated with an earlier age at disease onset (P=.004) and that PTPN22 has a stronger effect in males than in females (P=.03). A meta-analysis failed to demonstrate an association of the remaining alleles with RA susceptibility, suggesting that the previously published associations may represent false-positive results. Given the strong statistical power to replicate a true-positive association in this study, our results provide support for PTPN22, CTLA4, and PADI4 as RA susceptibility genes and demonstrate novel associations with clinically relevant subsets of RA.     

Association of the gene encoding wingless-type mammary tumor virus integration-site family member 5B (WNT5B) with type 2 diabetes

Recent reports have suggested that WNT signaling is an important regulator for adipogenesis or insulin secretion and might be involved in the pathogenesis of type 2 diabetes. To investigate possible roles of the WNT genes in conferring susceptibility to type 2 diabetes, we examined the association of the genes that encode members of the WNT family with type 2 diabetes in the Japanese population. First, 40 single-nucleotide polymorphism (SNP) loci within 11 WNT genes were analyzed in 188 subjects with type 2 diabetes (case-1) and 564 controls (control-1). Among them, six SNP loci exhibited a significant difference (P<.05) in the allele and/or genotype distributions between case and control subjects. These SNP loci were further analyzed in another set of case (case-2; n=733) and control (control-2; n=375) subjects to confirm their statistical significance. As a result, one SNP locus in the WNT5B gene was strongly associated with type 2 diabetes ( chi 2=15.6; P=.00008; odds ratio=1.74; 95% confidence interval 1.32-2.29). Expression of the WNT5B gene was detectable in several tissues, including adipose, pancreas, and liver. Subsequent in vitro experiments identified the fact that expression of the Wnt5b gene was increased at an early phase of adipocyte differentiation in mouse 3T3-L1 cells. Furthermore, overexpression of the Wnt5b gene in preadipocytes resulted in the promotion of adipogenesis and the enhancement of adipocytokine-gene expression. These results indicate that the WNT5B gene may contribute to conferring susceptibility to type 2 diabetes and may be involved in the pathogenesis of this disease through the regulation of adipocyte function.     

No association of XRCC1 polymorphisms Arg194Trp and Arg399Gln with colorectal cancer risk

Background: X-ray repair cross complementation group 1 (XRCC1) plays a key role in base excision repair. The purpose of this study was to examine the association of two genetic polymorphisms in XRCC1 (rs1799782 and rs25487) with risk of colorectal polyps and colorectal cancer (CRC). Methods: In the ongoing colorectal cancer study of Austria (CORSA), a total of 3091 Caucasian participants was genotyped using 5′-nuclease TaqMan assays. Multiple logistic regression was applied to compare individuals of the control group against three different case groups namely CRC cases, high-risk and low-risk polyps. Results: The two investigated SNPs in XRCC1 were not found to be associated with neither CRC risk nor polyp risk. Comparing the CRC cases versus the controls the OR was 0.60 (95%CI 0.27–1.31) for the heterozygous polymorphic genotype of SNP rs1799782 and 1.47 (95%CI 0.81–2.65) for the homozygous polymorphic genotype of SNP rs25487. Comparing the high-risk polyp group versus the controls the OR was 2.64 (95%CI 0.61–11.42) for the homozygous polymorphic genotype of SNP rs1799782 and 0.89 (95%CI 0.60–1.33) for SNP rs25487, respectively. In an haplotype analysis also no statistically significant association was found. Conclusion: Our finding that none of the two investigated SNPs of XRCC1 were significantly associated with risk of CRC or polyps is consistent with the results of a recently published meta-analysis.     

Association between common genetic variants in pre-microRNAs and gastric cancer risk in Japanese population

Background: Common single‐nucleotide polymorphisms (SNPs) in microRNAs (miRNA) have been shown to be associated with susceptibility to several human cancers. We evaluated the associations of three SNPs (rs11614913, rs2910164, and rs3746444) in pre‐miRNAs (miR‐196a2, miR‐146a, and miR‐499) with the risk of gastric cancer (GC) and peptic ulcer diseases, and with the severity of Helicobacter pylori‐induced gastritis in Japanese population. Methods: The rs11614913 (C>T), rs2910164 (G>C), and rs3746444 (A>G) SNPs were genotyped in 552 GC, and 697 non‐cancer subjects, including 141 gastric and 73 duodenal ulcer, and 483 non‐ulcer subjects. The degree of histologic gastritis was classified according to the updated Sydney System, and the serum pepsinogen levels were measured in selected 579 and 204 cases. Results: The rs2910164 CC genotype held a significantly higher risk of GC when compared to non‐cancer subjects (adjusted odds ratio (OR) = 1.30, 95% confidence interval (CI) = 1.02–1.66, p =.03). Similarly, the rs2910164 C carrier was associated with higher risk of GC when compared to both non‐cancer and non‐ulcer subjects (OR = 1.39, 95%CI = 1.00–1.93, p =.05, adjusted OR = 1.57, 95%CI = 1.09–2.27, p =.016, respectively). The rs2910164 CC genotype was associated with non‐cardia and upper third, diffuse type and advanced stage GC. The rs11614913 TT genotype was associated with higher degree of mononuclear cell infiltration (score 0–1 vs 2～, adjusted OR = 1.62, 95%CI = 1.05–2.49, p =.03). Conclusions: The rs2910164 (G>C) SNP in the miR‐146a is associated with susceptibility to GC. In addition, the rs11614913 (C>T) SNP in the miR‐196a2 is associated with the degree of H. pylori‐induced mononuclear cell infiltration.     

A case-control study of rheumatoid arthritis identifies an associated single nucleotide polymorphism in the <Emphasis Type="Italic">NCF4</Emphasis> gene,supporting a role for the NADPH-oxidase complex in autoimmunity

Rheumatoid arthritis (RA) is a chronic inflammatory disease with a heritability of 60%. Genetic contributions to RA are made by multiple genes, but only a few gene associations have yet been confirmed. By studying animal models, reduced capacity of the NADPH-oxidase (NOX) complex, caused by a single nucleotide polymorphism (SNP) in one of its components (the NCF1 gene), has been found to increase severity of arthritis. To our knowledge, however, no studies investigating the potential role played by reduced reactive oxygen species production in human RA have yet been reported. In order to examine the role played by the NOX complex in RA, we investigated the association of 51 SNPs in five genes of the NOX complex (CYBB, CYBA, NCF4, NCF2, and RAC2) in a Swedish case-control cohort consisting of 1,842 RA cases and 1,038 control individuals. Several SNPs were found to be mildly associated in men in NCF4 (rs729749, P = 0.001), NCF2 (rs789181, P = 0.02) and RAC2 (rs1476002, P = 0.05). No associations were detected in CYBA or CYBB. By stratifying for autoantibody status, we identified a strong association for rs729749 (in NCF4) in autoantibody negative disease, with the strongest association detected in rheumatoid factor negative men (CT genotype versus CC genotype: odds ratio 0.34, 95% confidence interval 0.2 to 0.6; P = 0.0001). To our knowledge, this is the first genetic association identified between RA and the NOX complex, and it supports previous findings from animal models of the importance of reactive oxygen species production capacity to the development of arthritis.     

Variants of MIRNA146A rs2910164 and MIRNA499 rs3746444 are associated with the development of cutaneous leishmaniasis caused by Leishmania guyanensis and with plasma chemokine IL-8

Leishmania are intracellular protozoan parasites that cause a wide spectrum of clinical manifestations in genetically susceptible individuals with an insufficient or balanced Th1 immune response to eliminate the parasite. MiRNAs play important regulatory role in numerous biological processes including essential cellular functions. miR146-a acts as an inhibitor of interleukin 1 receptor associated kinase 1 (IRAK1) and tumour necrosis factor (TNF) receptor associated factor 6 (TRAF6) present in the toll-like receptors pathway while miR499a modulates TGF-β and TNF signalling pathways. Here, we investigated whether MIRNA146A rs2910164 and MIRNA499 rs3746444 variants are associated with the development of L. guyanensis (Lg)-cutaneous leishmaniasis (CL). The variants MIR146A rs2910164 and MIR499A rs3746444 were assessed in 850 patients with Lg-CL and 891 healthy controls by polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP). Plasma cytokines were measured using the BioPlex assay. Carriers of rs2910164 CC genotype have 30% higher odds of developing CL (ORadj_age/sex = 1.3 [95%CI 0.9–1.8]; Padj_age/sex 0.14) compared to individuals with the genotype GG (ORadj_age/sex = 0.77 [95%CI 0.56–1.0]; Padj_age/sex 0.14) if exposed to Lg-infection. Heterozygous GC individuals also showed lower odds of developing CL (ORadj_age/sex = 0.77 [95%CI 0.5–1.1]; Padj_age/sex 0.09). Homozygosity for the allele C is suggestive of an association with the development of Lg-CL among exposed individuals to Lg-infection. However, the odds of developing CL associated with the CC genotype was evident only in male individuals (OR_adjage = 1.3 [95% CI = 0.9–2.0]; P_adjage = 0.06). Individuals homozygous for the G allele tend to have higher plasma IL-8 and CCL5. Similarly, for the MIR499A rs3746444, an association with the G allele was only observed among male individuals (OR = 1.4 [1.0–1.9]; P = 0.009). In a dominant model, individuals with the G allele (GG-GA) when compared to the AA genotype reveals that carriers of the G allele have 40% elevated odds of developing Lg-CL (ORadj_age = 1.4 [1.1–1.9]). Individuals with the GG genotype have higher odds of developing Lg-CL (ORadj_age/sex = 2.0 [95%CI 0.83–5.0]; P_adjage = 0.01. Individuals homozygous for the G allele have higher plasma IL-8. Genetic combinations of both variants revealed that male individuals exposed to Lg bearing three or four susceptible alleles have higher odds of developing Lg-CL (OR = 2.3 [95% CI 1.0–4.7]; p = 0.017). Both MIR146A rs2910164 and MIR499A rs3746444 are associated with the development of Lg-CL and this association is prevalent in male individuals.     

Interleukin-28B polymorphisms on the SVR in the treatment of naïve chronic hepatitis C with pegylated interferon-α plus ribavirin: A meta-analysis

There are accurate but inconclusive data on the association between single nucleotide polymorphisms (SNPs) of interleukin (IL)-28B and sustained virological response (SVR) in chronic hepatitis C (CHC). This meta-analysis aimed to derive a more precise estimation of the effects of IL-28B SNPs locus (rs12979860 and rs8099917) on SVR in naïve CHC patients receiving pegylated interferon alpha (PEG-IFN-α) plus ribavirin. Literature search was conducted up to June, 2011, in PubMed, EMBASE and Cochrane Database of Systematic Reviews. A total of 36 studies involving 10912 cases with CHC receiving PEG-IFN-α plus ribavirin met the inclusion criteria. Analyses were stratified either by ethnicity or genotype of hepatitis C virus. In genotype 1/4 patients, rs12979860 CC was associated with high SVR in CHC patients (Caucasian: odds ratio (OR), 4.567; 95% confidence interval (CI), 3.826–5.452; Asian: OR, 4.033; 95%CI, 3.050–5.333; African American: OR, 4.297; 95%CI, 2.168–8.515; Hispanics: OR, 4.350; 95%CI, 2.817–6.717) but had no effect in genotype 2/3. In Caucasian (genotype 1/4: OR, 2.542; 95%CI, 2.108–3.065; genotype 2/3: OR, 1.363; 95%CI, 1.020–1.820) and Asian (genotype 1/4: OR, 5.214; 95%CI, 3.694–7.360; genotype 2/3: OR, 1.785; 95%CI, 1.095–2.910), rs8099917 TT was associated with high SVR in both genotype 1/4 and 2/3. Meta-regression showed that in Caucasians with CHC genotype 1/4, gender male might contribute to the effect of rs12979860 on SVR but advanced fibrosis might weaken this effect. Furthermore, in Asians with CHC genotype 1/4, high baseline viral load and advanced fibrosis might also undermine the effect of rs8099917 on SVR. This meta-analysis suggested that IL-28B rs12979860 CC and rs8099917 TT were associated with high SVR rate in CHC genotype 1/4. In CHC genotype 2/3, rs8099917 TT carriers also had higher SVR.     

The BTNL2 gene and sarcoidosis susceptibility in African Americans and Whites

The BTNL2 gene is a member of the B7 receptor family that probably functions as a T-cell costimulatory molecule. It resides in the class II major histocompatibility complex (MHC) region of chromosome 6p and has recently been associated with sarcoidosis susceptibility in a white German population. We sought to replicate the BTNL2 association in an African American family-based study population (n=219 nuclear families) and two case-control populations--one African American (n=295 pairs) and one white (n=366 pairs). Ten SNPs were detected within a 490-bp region spanning exon/intron 5 of BTNL2. Haplotype variation within this region was significantly associated with sarcoidosis in all three study populations but more so in whites (P=.0006) than in the African American case-control (P=.02) or family-based (P=.03) samples. The previously reported BTNL2 SNP with the strongest sarcoidosis association, rs2076530, was also the SNP with the strongest association in our white population (P<.0001). The A allele of rs2076530 results in a premature exon-splice site and increases risk for sarcoidosis (odds ratio=2.03; 95% confidence interval 1.32-3.12). Although rs2076530 was not associated with sarcoidosis in either African American sample, a three-locus haplotype that included rs2076530 was associated with sarcoidosis across all three study samples. Multivariable logistic regression analyses showed that BTNL2 effects are independent of human leukocyte antigen class II genes in whites but may interact antagonistically in African Americans. Our results underscore the complexity of genetic risk for sarcoidosis emanating from the MHC region.     

Genetic association of the R620W polymorphism of protein tyrosine phosphatase PTPN22 with human SLE

We genotyped 525 independent North American white individuals with systemic lupus erythematosus (SLE) for the PTPN22 R620W polymorphism and compared the results with data generated from 1,961 white control individuals. The R620W SNP was associated with SLE (genotypic P=.00009), with estimated minor (T) allele frequencies of 12.67% in SLE cases and 8.64% in controls. A single copy of the T allele (W620) increases risk of SLE (odds ratio [OR]=1.37; 95% confidence interval [CI] 1.07-1.75), and two copies of the allele more than double this risk (OR=4.37; 95% CI 1.98-9.65). Together with recent evidence showing association of this SNP with type 1 diabetes and rheumatoid arthritis, these data provide compelling evidence that PTPN22 plays a fundamental role in regulating the immune system and the development of autoimmunity.     

Mitochondrial polymorphisms significantly reduce the risk of Parkinson disease

Mitochondrial (mt) impairment, particularly within complex I of the electron transport system, has been implicated in the pathogenesis of Parkinson disease (PD). More than half of mitochondrially encoded polypeptides form part of the reduced nicotinamide adenine dinucleotide dehydrogenase (NADH) complex I enzyme. To test the hypothesis that mtDNA variation contributes to PD expression, we genotyped 10 single-nucleotide polymorphisms (SNPs) that define the European mtDNA haplogroups in 609 white patients with PD and 340 unaffected white control subjects. Overall, individuals classified as haplogroup J (odds ratio [OR] 0.55; 95% confidence interval [CI] 0.34-0.91; P=.02) or K (OR 0.52; 95% CI 0.30-0.90; P=.02) demonstrated a significant decrease in risk of PD versus individuals carrying the most common haplogroup, H. Furthermore, a specific SNP that defines these two haplogroups, 10398G, is strongly associated with this protective effect (OR 0.53; 95% CI 0.39-0.73; P=.0001). SNP 10398G causes a nonconservative amino acid change from threonine to alanine within the NADH dehydrogenase 3 (ND3) of complex I. After stratification by sex, this decrease in risk appeared stronger in women than in men (OR 0.43; 95% CI 0.27-0.71; P=.0009). In addition, SNP 9055A of ATP6 demonstrated a protective effect for women (OR 0.45; 95% CI 0.22-0.93; P=.03). Our results suggest that ND3 is an important factor in PD susceptibility among white individuals and could help explain the role of complex I in PD expression.     

Preterm birth in Caucasians is associated with coagulation and inflammation pathway gene variants

Spontaneous preterm birth (<37 weeks gestation-PTB) occurs in approximately 12% of pregnancies in the United States, and is the largest contributor to neonatal morbidity and mortality. PTB is a complex disease, potentially induced by several etiologic factors from multiple pathophysiologic pathways. To dissect the genetic risk factors of PTB a large-scale high-throughput candidate gene association study was performed examining 1536 SNP in 130 candidate genes from hypothesized PTB pathways. Maternal and fetal DNA from 370 US Caucasian birth-events (172 cases and 198 controls) was examined. Single locus, haplotype, and multi-locus association analyses were performed separately on maternal and fetal data. For maternal data the strongest associations were found in genes in the complement-coagulation pathway related to decidual hemorrhage in PTB. In this pathway 3 of 6 genes examined had SNPs significantly associated with PTB. These include factor V (FV) that was previously associated with PTB, factor VII (FVII), and tissue plasminogen activator (tPA). The single strongest effect was observed in tPA marker rs879293 with a significant allelic (p = 2.30x10(-3)) and genotypic association (p = 2.0x10(-6)) with PTB. The odds ratio (OR) for this SNP was 2.80 [CI 1.77-4.44] for a recessive model. Given that 6 of 8 markers in tPA were statistically significant, sliding window haplotype analyses were performed and revealed an associating 4 marker haplotype in tPA (p = 6.00x10(-3)). The single strongest effect in fetal DNA was observed in the inflammatory pathway at rs17121510 in the interleukin-10 receptor antagonist (IL-10RA) gene for allele (p = 0.01) and genotype (p = 3.34x10(-4)). The OR for the IL-10RA genotypic additive model was 1.92 [CI 1.15-3.19] (p = 2.00x10(-3)). Finally, exploratory multi-locus analyses in the complement and coagulation pathway were performed and revealed a potentially significant interaction between a marker in FV (rs2187952) and FVII (rs3211719) (p<0.001). These results support a role for genes in both the coagulation and inflammation pathways, and potentially different maternal and fetal genetic risks for PTB.