Role of TNFRSF1B polymorphisms in the response of Crohn's disease patients to infliximab.

Infliximab (IFX) is a valid treatment for Crohn's disease (CD), but a relevant percentage of patients do not benefit from this therapy. In the Japanese population, the response to IFX was associated with markers in the TNF receptor superfamily 1A (TNFRSF1A) and 1B (TNFRSF1B) genes. We aimed to replicate the association previously described in the Japanese population and to ascertain the role of TNF receptors as modulators of the response to IFX. We studied 297 white Spanish CD patients with a known response to IFX: 238 responders and 59 primary nonresponders. Four single nucleotide polymorphisms (SNPs) were analyzed: rs767455 in TNFRSF1A and rs1061622, rs1061624, and rs3397 in TNFRSF1B. Comparisons between groups were performed with chi-square tests or the Fisher's exact test. Different features (sex, age, disease duration, smoking among others) were evaluated as possible confounding factors. No significant association was found between the studied TNFRSF1A polymorphisms and response to IFX. In the TNFRSF1B gene, the haplotype rs1061624_A-rs3397_T was significantly increased in nonresponders: p = 0.015, OR = 1.78, 95% CI 1.09-2.90; and an increased frequency of rs1061622_G carriers was observed in patients with remission: p = 0.033 vs nonresponders and p = 0.023 vs patients with a partial response. Our results support a role of TNFRSF1B gene variants in the response to IFX in CD patients.

The R30Q DLG5 variant is not associated with celiac disease or inflammatory bowel disease in the Spanish population.

Alterations in intestinal epithelial permeability could underlie inflammatory bowel disease (IBD) and celiac disease (CeD) etiology, as supported by previous association studies. One related gene, DLG5 [discs, large homologue 5 (Drosophila)], has been associated with IBD in several populations and with CeD in the Dutch population. We tried to confirm the involvement of DLG5 in CeD performing a case-control study (725 CeD patients and 803 controls) by analysing the R30Q variant (rs1248696). Genetic frequencies did not significantly differ between groups (P > 0.80) and the meta-analysis with the Dutch data did not show any association. Additionally, we evaluated the effect of R30Q in IBD risk (858 patients), as discordant results were previously obtained. No association was detected. Our study does not support the effect of the R30Q DLG5 variant in CeD or IBD predisposition in the Spanish population.

Members 6B and 14 of the TNF receptor superfamily in multiple sclerosis predisposition.

TNFRSF6B and TNFRSF14 genes were recently associated with Crohn's disease and rheumatoid arthritis. TNFRSF14 is known as herpes virus entry mediator (HVEM), and herpes viruses have been involved in the aetiology of multiple sclerosis (MS). MS patients present human herpes virus 6 (HHV6) in active plaques and increased antibody responses to HHV6. We aimed to ascertain the role of these genes in MS susceptibility and to investigate the relationship of the gene encoding the widely expressed HVEM receptor with the active replication of HHV6 found in some MS patients. Genotyping of 1370 Spanish MS patients and 1715 ethnically matched controls was performed. HHV6A DNA levels (surrogate of active viral replication) were analysed in serum of MS patients during a 2-year follow-up. Both polymorphisms were associated with MS predisposition, with stronger effect in patients with HHV6 active replication-TNFRSF6B-rs4809330(*)A: P=0.028, OR=1.13; TNFRSF14-rs6684865(*)A: overall P=0.0008, OR=1.2; and HHV6-positive patients vs controls: P=0.017, OR=1.69.

Association between idiopathic achalasia and IL23R gene.

BACKGROUND: Idiopathic achalasia is a primary esophageal motor disorder of unknown etiology. Different evidences have been reported in support of achalasia as the result of an autoimmune and inflammatory process leading to neuronal cell loss. According to this, idiopathic achalasia has been significantly associated with specific alleles of the human leukocyte antigen system class II, although few reports studying association with other loci can be found in the literature. Recent studies have shown association of a non-synonymous polymorphism within the IL23R gene with different chronic inflammatory disorders, including Barrett's esophagus. The purpose of this study was to assess whether the IL23R coding variant Arg381Gln polymorphism is involved in susceptibility to idiopathic achalasia. METHODS: We performed a case-control study including 262 patients with idiopathic achalasia and 802 healthy subjects, all of them white Spaniards. Achalasia patients were diagnosed on the basis of clinical, radiographic, endoscopic, and manometric criteria. All samples were genotyped for the IL23R Arg381Gln polymorphism using TaqMan technology. KEY RESULTS: The minor allele of the Arg381Gln polymorphism was significantly increased in patients compared with healthy controls (OR = 1.46, 95% CI = 1.01-2.11, P = 0.036). This association seems to be specific to male patients with disease onset after 40 years (OR = 2.33, 95% CI = 1.29-4.16, P = 0.002). CONCLUSIONS & INFERENCES: Our results suggest a role of IL23R in idiopathic achalasia predisposition and extend the evidence of the general influence of this gene in autoimmune and inflammatory diseases.

STAT3 locus in inflammatory bowel disease and multiple sclerosis susceptibility.

STAT3 (signal transducer and activator of transcription 3) signaling is a critical component of Th17-dependent autoimmune processes. Genome-wide association studies (GWAS) have revealed the role of the STAT3 gene in inflammatory bowel disease (IBD) susceptibility, although confirmation in clinical subphenotypes is warranted. Mice with targeted deletion of Stat3 in T cells are resistant to experimental autoimmune encephalomyelitis, which is a multiple sclerosis (MS) model. Moreover, increased phosphorylated STAT3 was reported in T cells of patients evolving from clinically isolated syndrome to defined MS and in relapsing patients. These evidences led us to analyze the role of STAT3 in Crohn's disease (CD), ulcerative colitis (UC) and MS risk. Polymorphisms in the STAT3 region (rs3809758/rs744166/rs1026916/rs12948909) were genotyped and the inferred haplotypes were subsequently analyzed in 860 IBD and 1540 MS Spanish patients and 1720 ethnically matched controls. The haplotype conformed by the risk alleles of each polymorphism was significantly associated with both clinical phenotypes of IBD (CD: P=0.005, odds ratio 1.25, 95% confidence interval 1.06-1.46; and UC: P=0.002, odds ratio 1.19, 95% confidence interval 1.02-1.38). No evidence of association was detected for MS. The originally described association of IBD with STAT3 polymorphisms is corroborated for the two clinical phenotypes, CD and UC, in an independent population. A major role of this gene in MS seems unlikely.

Effect of BSN-MST1 locus on inflammatory bowel disease and multiple sclerosis susceptibility.

Genome-wide studies highlighted the effect in Crohn's disease (CD) and ulcerative colitis (UC) susceptibility of single nucleotide polymorphisms (SNPs) in 3p21, where BSN (bassoon), MST1 (macrophage stimulating-1) and MST1R (MST1 Receptor) genes map. MST1R expression was significantly downregulated in multiple sclerosis (MS) compared with control brains, resembling findings in the MS mouse model. We pursued to replicate the effect of this locus on inflammatory bowel diseases and to evaluate its contribution to MS risk. Polymorphisms rs9858542, rs2131109 and rs1128535 were analysed by TaqMan assays in Spanish patients (370 CD, 405 UC and 415 MS) and 800 ethnically matched controls. Allele frequencies of these SNPs were significantly different in CD patients compared with controls [rs9858542: P=0.001, Odds ratio (OR)=1.35; rs2131109: P=0.0005, OR=1.37; rs1128535: P=0.007, OR=0.78] and, specifically, in the ileal phenotype [rs9858542: P=0.0004, OR=1.47; rs2131109: P=0.00009, OR=1.52; rs1128535: P=0.02, OR=0.69]. No differences were detected between UC or MS patients and control individuals. The effect of this locus on CD predisposition was replicated, but no influence on UC or MS predisposition could be detected. This susceptibility locus seems to affect mainly to the ileal CD subphenotype, although this point awaits further corroboration in independent cohorts.

Lack of replication of celiac disease risk variants reported in a Spanish population using an independent Spanish sample.

Celiac disease (CD) is an inflammatory condition affecting small bowel and triggered by gluten (or related proteins) ingestion in genetic susceptible individuals. Polymorphisms in three genes, SERPINE2, PPP6C and PBX3, have recently been associated with CD in the Spanish population. However, this association could not be replicated in the UK population using imputed data. As this second study analyzed a different population, we aimed at reevaluating the role of those polymorphisms using an independent Spanish sample. We genotyped three single nucleotide polymorphisms: rs6747096 in SERPINE2, rs458046 in PPP6C and rs7040561 in PBX3, in 417 CD patients, 527 ethnically matched healthy controls and parents of 304 CD patients. A case-control study using the chi(2)-test and a familial study using the transmission disequilibrium test were performed. No association was detected in those analyses. Therefore, our results seem to discard the role of the previously described polymorphisms in SERPINE2, PPP6C and PBX3 in CD susceptibility.

Role of polymorphisms in the TNFRSF13B (TACI) gene in Spanish patients with immunoglobulin A deficiency.

Mutations in the TNFRSF13B (TACI) gene have been associated with common variable immunodeficiency, and a role in immunoglobulin A deficiency (IgAD) has also been suggested. We aimed at studying the role of several polymorphisms along this gene in IgAD susceptibility. Three TNFRSF13B mutations (C104R, A181E and R202H) and eight additional single nucleotide polymorphisms in the gene were genotyped in 338 Spanish IgAD patients and 553 ethnically matched healthy controls and tested for association. Data from parents of 114 IgAD patients were also collected and used for additional analysis. No statistically significant differences were observed after comparing patients and controls for any single nucleotide polymorphism analysed. Therefore, our work seems to discard a role of TNFRSF13B mutations in IgAD, concordantly with the most recent published studies.

Association of MYO9B haplotype with type 1 diabetes.

MYO9B (myosin IXB) polymorphisms were associated with celiac disease and ulcerative colitis susceptibility, presumably through alteration of the intestinal permeability. Recently this gene was also associated with several diseases with an autoimmune component, such as rheumatoid arthritis and systemic lupus erythematosus. We aimed to test, for the first time, the potential role of MYO9B polymorphisms in type 1 diabetes (T1D), an autoimmune condition preceded by changes in intestinal barrier integrity. Three previously associated MYO9B polymorphisms (rs962917, rs2279003, and rs2305764) were studied in 316 T1D patients and 706 ethnically matched controls. Minor alleles of those polymorphisms were more frequent in diabetic patients than in controls and the haplotype carrying major alleles in those positions, rs962917*G/rs2279003*C/rs2305764*G, significantly reduced the risk of T1D in the Spanish population (p = 0.004; OR [95% confidence interval] = 0.68 [0.52-0.90]). Our data suggest an involvement of this MYO9B chromosomal region in T1D predisposition, indicating extensive influence on autoimmune diseases.

No evidence of association of the MYO9B polymorphisms with celiac disease in the Spanish population.

Inconsistent results concerning the association of polymorphisms in the MYO9B gene with celiac disease (CD) have been recently published. This gene encodes a myosin with a guanosine-triphosphatase (GTPase)-activating protein domain for the Rho-family of small G proteins, which are involved in cytoskeleton remodeling and therefore potentially involved in intestinal permeability. Functional and positional reasons led us to investigate the role of MYO9B polymorphisms in the Spanish CD population. A case-control study, including 415 CD patients and 433 ethnically matched healthy controls, and a familial study, including parents of 145 of those CD patients, was performed. Six MYO9B variants previously associated with CD were analyzed: rs2305767, rs2279003, rs962917, rs1457092, rs2305765 and rs2305764. No MYO9B variants or MYO9B haplotypes were found associated with CD, either before or after stratification of the patients for the human leucocyte antigen (HLA)-DQ2-positive risk factor. The family study revealed no distorted transmission of the aforementioned MYO9B polymorphisms or haplotypes. Our results support a negligible influence of this gene on CD predisposition.

The functional genetic variation in the PTPN22 gene has a negligible effect on the susceptibility to develop inflammatory bowel disease.

The aim of this study was to assess the possible association between the protein tyrosine phosphatase non-receptor 22 (PTPN22) gene 1858C-->T (rs2476601, encoding R620W) polymorphism and inflammatory bowel disease (IBD). Our study population consisted of 1113 IBD [544 ulcerative colitis (UC) and 569 Crohn's disease (CD)] patients and 812 healthy subjects. All the individuals were of Spanish white origin. Genotyping of the PTPN22 gene 1858C-->T polymorphism was performed by real time polymerase chain reaction technology, using TaqMan 5'-allelic discrimination assay. The frequency of the PTPN22 1858T allele in healthy subjects was 6.2% compared with 6.7% in the UC patients and 5.1% in Crohn's patients. No statistically significant differences were observed when the PTPN22 1858C-->T allele and genotype distribution among CD patients, UC patients and healthy controls were compared. These results indicate that the PTPN22 1858C-->T polymorphism does not appear to play a major role in IBD predisposition in our population.

DRB1-TNF-alpha-TNF-beta haplotype is strongly associated with severe aortoiliac occlusive disease, a clinical form of atherosclerosis.

Severe aortoiliac occlusive disease (AOD) is a clinical manifestation of peripheral arteriosclerosis. Atherosclerosis has been associated with some human leukocyte antigen (HLA)-DRB1 alleles, stressing its relationship with autoimmune or inflammatory disorders. Additionally, in rheumatoid arthritis patients, the DRB1*0404 allele is specifically associated with endothelial dysfunction. Our objective was to assess the role of class II HLA alleles in the susceptibility to AOD; a combined study of the nearby tumor necrosis factor (TNF) locus was also performed. We included 104 AOD patients and 504 healthy controls from Madrid. DRB1 typing and DRB1*04 subtyping was done by polymerase chain reaction amplification followed by hybridization with specific oligonucleotides. TNF-alpha and TNF-beta microsatellites were studied by polymerase chain reaction and capillary electrophoresis. None of the markers was associated with AOD, although a trend was observed for DRB1*0404 (OR = 2.18; p = 0.05). However, among DRB1*0404 individuals, the TNFa11-b4 pair was present more frequently in patients than in controls (OR = 16.0; p = 0.007). The combined appearance of TNFa11-b4 and DRB1*0404 was much more frequent in patients than in controls (OR = 5.92; p = 0.0013), a result enhanced by haplotypic estimates (OR = 10.0; p = 0.00017). Our results show that the HLA region modulates the predisposition to AOD. More specifically, they suggest that an extended haplotype encompassing DRB1*0404 and TNFa11-b4 carries a genetic factor conferring susceptibility to AOD.

TNF-376A marks susceptibility to MS in the Spanish population: A replication study.

This study was designed as a reappraisal of the association between the TNF-376A promoter polymorphism and susceptibility to multiple sclerosis found in the Spanish population but not in other populations. With a new dataset of patients (n = 241) and control subjects (n = 288), the association was confirmed (p = 0.018). The authors' data suggest that this association is specific of the Spanish white (or related) population or, alternatively, that only studies in their population have the adequate statistical power because of the higher frequency of an extended, conserved haplotype carrying the TNF-376A allele.

Prevalence of mutations of the NOD2/CARD15 gene and relation to phenotype in Spanish patients with Crohn disease.

BACKGROUND: We assessed the prevalence of R702W, G908R, and L1007fs coding mutations in the NOD2/CARD15 gene and the genotype-phenotype relation in Spanish patients with Crohn disease. METHODS: A cohort of 204 unrelated patients with Crohn disease and 140 healthy controls were studied. The phenotype was established before commencement of genotyping. Genotyping of the R702W, G908R, and L1007fs gene polymorphisms of NOD2/CARD15 was performed by two independent laboratories using different techniques. In the case of discordant results, specific sequencing of DNA strands was performed. RESULTS: At least one mutation was present in 32.8% of patients compared to 10.7% in controls (OR = 4.08, 95% CI 2.21 to 7.50). In patients with Crohn disease, the frequency of R702W, G908R, and L1007fs carriers was 13.7%, 8.3%, and 14.2%, respectively. Compound heterozygotes and homozygotes occurred in 3.4% and 2.9% of patients and in none of the controls. The correlation of genotype-Vienna classification showed a significant association with ileal disease (RR = 1.61, 95% CI 1.21-2.15, P = 0.001) and an inverse association with colonic localization (RR = 0.29, 95% CI 0.11-0.80, P = 0.007). There was a significant association between G908R carriership and previous appendectomy, surgical interventions, and stricturing behavior. A gene-dosage effect on phenotypic characteristics was not observed. CONCLUSIONS: In a Spanish population from Madrid, mutations of the NOD2/CARD15 gene were a marker of susceptibility to Crohn disease and were associated with ileal disease. Carriers of the G908R mutation showed a stricturing disease behavior, history of appendectomy, and surgical interventions over the course of the disease.

Cloning and functional characterization of the 5' regulatory region of the human mitochondrial glycerol-3-phosphate dehydrogenase gene. Lack of 3,5,3'-triiodothyronine responsiveness in adipose tissue.

We report data on the structural and functional characterization of the 5' flanking region of the human mitochondrial glycerol-3-phosphate dehydrogenase (mtGPDH) gene. We found two regions upstream of 5'-untranslated sequences exhibiting promoter activity in transient transfection assays. Transcription start sites and potential regulatory sites in both promoter regions were defined. The proximal promoter was approximately sevenfold more active than the distal one in most cell lines, but it was only twice as active in a neuroblastoma cell line. These observations seem to indicate that the rate of transcription, as well as the tissue-specific expression of the human mtGPDH gene, is the result of a combinatorial effect of transcription factors on at least two promoters. 3,5,3'-Triiodothyronine failed to alter the transcriptional activity of human mtGPDH promoter(s) constructs in transient transfection assays. Although this finding seems to be in conflict with the reported effect of 3,5,3'-triiodothyronine in rodents, it is consistent with our observation of 3,5, 3'-triiodothyronine stimulation of mtGPDH activity in primary cultures of rat adipocytes, but not human cultured adipocytes, suggesting distinct regulation of this gene in both species.

High-efficiency transfer of the T cell co-stimulatory molecule B7-2 to lymphoid cells using high-titer recombinant adeno-associated virus vectors.

Adeno-associated virus (AAV) is a single-stranded DNA virus that can either integrate or replicate in host cells. Production of recombinant viral particles (rAAV) requires expression of the viral structural genes and the viral inverted terminal repeats in cis. By using an SV40 replicon to amplify the structural genes, the yield of recombinant viral particles was increased 60-fold over a nonreplicating helper plasmid. The rAAV particles produced by this system have similar physical properties to wild-type particles, including buoyant density, size, and morphology. This novel rAAV packaging system was used to produce rAAV particles that contain the gene for the T cell co-stimulatory protein B7-2. Transduction of the human nonadherent lymphoid cell line LP-1 with these particles significantly increased the percentage of cells expressing B7-2 from 6.8% to 78.0%. Expression of B7-2 in the human lymphoid cell line RPMI-8226 was also substantially increased. Targeting of tumor cells grown in suspension was hampered by low-efficiency transduction using other viral or nonviral vector systems. Our new packaging system for recombinant AAV should allow generation of sufficient quantities of B7-2 containing particles to develop tumor vaccines for non-Hodgkin's lymphoma.