Food groups associated with immune-mediated inflammatory diseases: a Mendelian randomization and disease severity study.

BACKGROUND/OBJECTIVES: Immune-mediated inflammatory diseases (IMIDs) are prevalent diseases. There is, however, a lack of understanding of the link between diet and IMIDs, how much dietary patterns vary between them and if there are food groups associated with a worsening of the disease. SUBJECTS/METHODS: To answer these questions we analyzed a nation-wide cohort of n = 11,308 patients from six prevalent IMIDs and 2050 healthy controls. We compared their weekly intake of the major food categories, and used a Mendelian randomization approach to determine which dietary changes are caused by disease. Within each IMID, we analyzed the association between food frequency and disease severity. RESULTS: After quality control, n = 11,230 recruited individuals were used in this study. We found that diet is profoundly altered in all IMIDs: at least three food categories are significantly altered in each disease (P < 0.05). Inflammatory bowel diseases showed the largest differences compared to controls (n ≥ 8 categories, P < 0.05). Mendelian randomization analysis supported that some of these dietary changes, like vegetable reduction in Crohn's Disease (P = 2.5 × 10-10, OR(95% CI) = 0.73(0.65, 0.80)), are caused by the disease. Except for Psoriatic Arthritis and Systemic Lupus Erythematosus, we have found ≥2 food groups significantly associated with disease severity in the other IMIDs (P < 0.05). CONCLUSIONS: This cross-disease study demonstrates that prevalent IMIDs are associated to a significant change in the normal dietary patterns. This variation is highly disease-specific and, in some cases, it is caused by the disease itself. Severity in IMIDs is also associated with specific food groups. The results of this study underscore the importance of studying diet in IMIDs.

Expression patterns common and unique to ulcerative colitis and celiac disease.

Autoimmune diseases like celiac disease (CeD) and ulcerative colitis (UC) show a common genetic background defined by the existence of shared susceptibility loci. We aimed to go deeper into this common genetic background through performing a cross-disease study based on gene expression. We measured the expression of 21 genes located in 13 CeD-UC susceptibility regions, and 10 genes in five CeD risk regions. Determinations were carried out in colon/rectum samples from 13 UC patients (inflamed and uninflamed tissue) and four colon samples from controls. Duodenal samples from 19 CeD patients and 12 controls were used for comparisons. Differences were analyzed using the Bayesian method. The shared chromosomal regions containing TNFAIP3, PTPN2, ICOSLG, C1orf106, and IL21 showed similar results in both diseases. FASLG, PLEK, CCR4, and TAGAP, all located in CeD risk loci, were up-regulated in both CeD and UC patients. Finally, ZFP36L1, ZMIZ1, PUS10, UBE2L3, and BACH2 showed opposite results in CeD and UC. A high complexity underlies autoimmune common susceptibility loci, as the expression pattern of the studied genes does not always correlate with the one expected attending to the apparent genetic background. Differentially expressed genes such as ZFP36L1, ZMIZ1, PUS10, and BACH2 deserve further research in autoimmune diseases.

Response to Infliximab in Crohn's Disease: Genetic Analysis Supporting Expression Profile.

Substantial proportion of Crohn's disease (CD) patients shows no response or a limited response to treatment with infliximab (IFX) and to identify biomarkers of response would be of great clinical and economic benefit. The expression profile of five genes (S100A8-S100A9, G0S2, TNFAIP6, and IL11) reportedly predicted response to IFX and we aimed at investigating their etiologic role through genetic association analysis. Patients with active CD (350) who received at least three induction doses of IFX were included and classified according to IFX response. A tagging strategy was used to select genetic polymorphisms that cover the variability present in the chromosomal regions encoding the identified genes with altered expression. Following genotyping, differences between responders and nonresponders to IFX were observed in haplotypes of the studied regions: S100A8-S100A9 (rs11205276* G/rs3014866* C/rs724781* C/rs3006488* A; P = 0.05); G0S2 (rs4844486* A/rs1473683* T; P = 0.15); TNFAIP6 (rs11677200* C/rs2342910* A/rs3755480* G/rs10432475* A; P = 0.10); and IL11 (rs1126760* C/rs1042506* G; P = 0.07). These differences were amplified in patients with colonic and ileocolonic location for all but the TNFAIP6 haplotype, which evidenced significant difference in ileal CD patients. Our results support the role of the reported expression signature as predictive of anti-TNF outcome in CD patients and suggest an etiological role of those top-five genes in the IFX response pathway.

Imaging Crohn disease: MR enterography.

Magnetic resonance enterography in Crohn disease management has been rapidly growing in importance during recent years. Being familiar to this technique is essential for radiologists and also, to some extent, for gastroenterologists. Our aim is to study and describe the imaging findings in magnetic resonance enterography in Crohn disease to develop a comprehensive and useful review article and imaging atlas.

A genome-wide association study on a southern European population identifies a new Crohn's disease susceptibility locus at RBX1-EP300.

OBJECTIVE: Genome-wide association studies (GWAS) have identified multiple risk loci for Crohn's disease (CD). However, the cumulative risk exerted by these loci is low, and the likelihood that additional, as-yet undiscovered loci contribute to the risk of CD is very high. We performed a GWAS on a southern European population to identify new CD risk loci. DESIGN: We genotyped 620 901 genome markers on 1341 CD patients and 1518 controls from Spain. The top association signals representing new candidate risk loci were subsequently analysed in an independent replication cohort of 1365 CD patients and 1396 controls. RESULTS: We identified a genome-wide significant association on chromosome 22q13.2 in the intergenic region between the RBX1 and EP300 genes (single nucleotide polymorphism rs4820425, OR 1.27, 95% CI 1.17 to 1.38, p=3.42E-8). We also found suggestive evidence for the association of the IFNGR2 (21q22.11), FOXP2 (7q31), MACROD2 (20p12.1) and AIF1 (6p21.3) loci with CD risk. CONCLUSIONS: In this GWAS performed on a southern European cohort, we have identified a new risk locus for CD between RBX1 and EP300. This study demonstrates that using populations of different ancestry is a useful strategy to identify new risk loci for CD.

Methotrexate in inflammatory bowel disease: a multicenter retrospective study focused on long-term efficacy and safety. The Madrid experience.

BACKGROUND: Methotrexate is useful in inflammatory bowel disease (IBD), but its role is secondary because of its limited experience and a supposedly unfavorable safety profile. AIM: To describe the efficacy and safety of methotrexate in a long-term real clinical practice. METHODS: Retrospectively reviewed records of IBD patients treated with methotrexate in eight hospitals of Madrid (Spain). RESULTS: A total of 77 patients were included (80% Crohn's disease); 94% received methotrexate because of steroid dependency. Overall, 82% of the patients initially responded (28% remission). Eighty-eight percent of the patients followed maintenance treatment for a mean of 17 (range: 1-108) months. Forty percent of the patients lost response at a mean of 57 weeks after starting methotrexate. No statistically significant differences were found in the response rates in terms of the disease type, route of administration, or the Montreal Classification category. The mean methotrexate cumulative dose was 1108 mg (range: 25-6480). The main adverse events included 10 cases of gastrointestinal symptoms, four of myelotoxicity, and 10 of abnormal liver function tests, and led to methotrexate withdrawal in four (5%) patients. Transient elastography, performed in 46 patients, detected six additional cases with significant fibrosis and normal liver function tests. CONCLUSION: Methotrexate is useful in inducing a response in IBD, although its efficacy decreases frequently through the follow-up. Although methotrexate seems safe in the long term, in addition to biochemical controls, a more accurate method to detect liver damage should be considered.

Adalimumab reversed a severe lymphopenia in a patient with Crohn's disease.

Patients with Crohn's disease are frequently found to have low peripheral lymphocyte counts. Lymphopenia has been linked to disease activity, the effects of therapy and the presence of an abnormal T regulatory (T(reg)) function. We present a patient with Crohn's disease and a severe total and CD4 lymphopenia that did not resolve after discontinuation of immunosuppressive treatment and resective surgery. Complete clinical remission and persistent normal levels of total and CD4 lymphocytes were observed after starting therapy with the anti-tumor necrosis factor monoclonal antibody adalimumab.

Analysis of the influence of two CD24 genetic variants in Crohn's disease and ulcerative colitis.

The aim of this study was to evaluate the possible implication of CD24 gene in the genetic predisposition to inflammatory bowel disease (IBD). Our study population consisted of 1321 female Spanish individuals (369 Crohn's disease [CD] patients, 323 ulcerative colitis [UC] patients, and 629 healthy matched controls). Two putative functional polymorphisms, a C to T coding polymorphism (rs8734) and a TG deletion in the 3' untranslated region (rs3838646), were used as CD24 genetic markers and genotyped using a Taqman 5' allelic discrimination assay. The "del" allele of the dinucleotide deletion was associated with an increased risk of CD (odds ratio = 1.61, 95% confidence interval = 1.17-2.21, p(FDR) = 6.4E-03) but not with UC. Moreover, this allele was significant associated with the age of CD diagnosis between 17 and 40 years, the ileocolonic location, and the inflammatory behavior of CD. We observed no significant differences between the allelic or genotypic frequencies of the A57V polymorphism in our studied IBD cohort. Our results suggest that the rs3838646 CD24 polymorphism is part of the genetic background of CD.

Differential association of two PTPN22 coding variants with Crohn's disease and ulcerative colitis.

BACKGROUND: The PTPN22 gene is an important risk factor for human autoimmunity. The aim of this study was to evaluate for the first time the role of the R263Q PTPN22 polymorphism in ulcerative colitis (UC) and Crohn's disease (CD), and to reevaluate the association of the R620W PTPN22 polymorphism with both diseases. METHODS: A total of 1677 UC patients, 1903 CD patients, and 3111 healthy controls from an initial case-control set of Spanish Caucasian ancestry and two independent sample sets of European ancestry (Dutch and New Zealand) were included in the study. Genotyping was performed using TaqMan SNP assays for the R263Q (rs33996649) and R620W (rs2476601) PTPN22 polymorphisms. Meta-analysis was performed on 6977 CD patients, 5695 UC patients, and 9254 controls to test the overall effect of the minor allele of R620W and R263Q polymorphisms. RESULTS: The PTPN22 263Q loss-of-function variant showed initial evidence of association with UC in the Spanish cohort (P = 0.026, odds ratio [OR] = 0.61, 95% confidence interval [CI]: 0.39-0.95), which was confirmed in the meta-analysis (P = 0.013 pooled, OR = 0.69, 95% CI: 0.51-0.93). In contrast, the 263Q allele showed no association with CD (P = 0.22 pooled, OR = 1.16, 95% CI: 0.91-1.47). We found in the pooled analysis that the PTPN22 620W gain-of-function variant was associated with reduced risk of CD (P = 7.4E-06 pooled OR = 0.81, 95% CI: 0.75-0.89) but not of UC (P = 0.88 pooled, OR = 0.98, 95% CI: 0.85-1.15). CONCLUSIONS: Our data suggest that two autoimmunity-associated polymorphisms of the PTPN22 gene are differentially associated with CD and UC. The R263Q polymorphism only associated with UC, whereas the R620W was significantly associated with only CD.

Long-term durability of infliximab treatment in Crohn's disease and efficacy of dose "escalation" in patients losing response.

BACKGROUND: The efficacy of infliximab therapy in patients with Crohn's disease (CD) is unknown beyond 12 months. For patients who lose their initial response, consideration can be given to dose "escalation" to regain therapeutic benefit. AIM: Our primary goal was to evaluate the long-term durability of maintenance infliximab treatment. The secondary goals were to identify potential predictors of loss of infliximab efficacy, to evaluate the response to infliximab escalation, and the safety of the treatment with infliximab with and without escalation of dose. METHODS: CD patients treated with infliximab with response to an induction regimen were evaluated. Maintenance of long-term response was estimated using Kaplan-Meier analysis. The effect of specific variables was calculated using logistic regression analysis. Efficacy of dose escalation in patients who lose response to infliximab was analyzed. RESULTS: Three hundred and nine CD patients were included. The mean follow-up time with infliximab treatment was 41 months, and the majority (95%) were on concomitant immunosuppressive therapy. The annual risk of loss of response to infliximab was 12% per patient-year of treatment. After loss of response, 41% of patients were managed with infliximab therapy escalation. After the first intensified dose, 56% of patients achieved remission and 40% partial response. Concurrent immunomodulators enhanced and smoking decreased the proportion of patients who maintained response (P<0.05). CONCLUSIONS: A relevant proportion of CD patients on long-term infliximab treatment loss response. After loss of response, a high proportion of these patients initially respond to infliximab dose escalation. Concurrent immunomodulators may increase and smoking may decrease maintenance of response.

Role of ATG16L1 Thr300Ala polymorphism in inflammatory bowel disease: a Study in the Spanish population and a meta-analysis.

BACKGROUND: Thr300Ala polymorphism in ATG16L1 was reported as a susceptibility factor to Crohn's disease (CD). Inconsistently replicated associations with ulcerative colitis (UC) and specifically with ileal CD were also reported. Our aims were: to replicate the ATG16L1 Thr300Ala association with inflammatory bowel disease (IBD) in the Spanish population, to perform a meta-analysis to determine the risk conferred to the different IBD subgroups, and to test for the interaction with CARD15 or IL23R risk loci. METHODS: Thr300Ala (rs2241880) single nucleotide polymorphism (SNP) was genotyped in 712 IBD patients and 745 controls by TaqMan technology. Genetic frequencies were compared with chi-square tests. Our findings were pooled in a meta-analysis. RESULTS: In Spain, we observed an association of rs2241880 with CD (P = 0.008; odds ratio [OR, 95% confidence interval, CI] = 1.28 [1.06-1.54]), but not with UC. No significant differences emerged when patients were stratified by clinical features. Similarly, the meta-analysis demonstrated a significant association only with CD (P < 10(-4); OR [95% CI] = 1.33 [1.28-1.38]). A significant difference between ileal CD patients and controls was observed, but heterogeneity was found in comparisons involving colonic CD patients and definite conclusions cannot be drawn. No interaction between rs2241880 and the established CARD15 or IL23R susceptibility variants was observed. CONCLUSIONS: The Thr300Ala polymorphism is associated with CD, regardless of the CARD15 or IL23R status, but not with UC. Stratification by clinical phenotypes did not show definitive results because of the existing heterogeneity among studies.

Novel association of the interleukin 2-interleukin 21 region with inflammatory bowel disease.

OBJECTIVES: Genome-wide association studies have reported the role of the interleukin (IL) 2-IL21 chromosomal region at 4q27 in several autoimmune conditions. Mice deficient in IL-2 develop a disease with clinical and histological similarity to ulcerative colitis (UC) in humans. Modest evidence of linkage with UC was tentatively proposed for the IL2 gene more than a decade ago. Therefore, we decide to investigate the association of polymorphisms in the IL-2 axis (IL2, IL2RA, and IL2RB genes) with inflammatory bowel diseases (IBDs). METHODS: Seven hundred and twenty-eight white Spanish unrelated IBD patients (356 Crohn's disease (CD) and 372 UC) and 549 ethnically matched controls were included in a case-control study. In addition, a Spanish replication cohort with 562 CD and 430 UC patients and 1,310 controls were analyzed. Eight single-nucleotide polymorphisms previously associated with different autoimmune diseases were analyzed using TaqMan chemistry. RESULTS: The IL2-rs6822844 polymorphism modified CD predisposition (P=0.002; odds ratio, OR (95% confidence interval, CI)=0.61 (0.44-0.84)); this was replicated in the other Spanish cohort, resulting in a strong protective effect of the minor allele in the merged samples (P=0.0002; OR (95% CI)=0.70 (0.58-0.85)). A similar effect of rs6822844 was detected for UC. Another marker, rs11938795, also showed evidence of an association with CD (P=0.006; OR (95% CI)=0.73 (0.58-0.92)). CONCLUSIONS: Polymorphisms within the IL2-IL21 linkage disequilibrium (LD) block show a novel association with IBD, this is concordant with suggestive previous results of whole genome analyses in CD and type 1 diabetes. Our data agree with the effect previously observed for other conditions and delineate a shared underlying mechanism.

Specific association of a CLEC16A/KIAA0350 polymorphism with NOD2/CARD15(-) Crohn's disease patients.

Independent genome-wide association studies highlighted the function of CLEC16A/KIAA0350 polymorphisms modifying the risk to either multiple sclerosis (rs6498169) or type 1 diabetes (rs2903692). This C-type lectin gene maps to a linkage disequilibrium block at 16p13 and a functional role of this gene could be envisaged for other immune-related conditions, such as inflammatory bowel disease (IBD). The present study, aimed at investigating the association of those two polymorphisms with IBD, included 720 IBD patients and 550 ethnically matched healthy controls. The effect of rs2903692 previously described in diabetes was observed specifically for Crohn's disease (CD) patients lacking the main susceptibility factor described to date, that is, three polymorphisms within another pattern recognition gene, NOD2/CARD15 (NOD2(-) vs NOD2(+) CD patients, G vs A: P=0.008; OR (95% CI)=1.54 (1.10-2.15); NOD2(-) CD patients vs controls: P=0.008; OR (95% CI)=1.37 (1.08-1.73)). Replication of these findings was performed in independent Spanish cohorts of 544 IBD patients and 340 controls and the combined data yielded significant differences (405 NOD2(-) vs 204 NOD2(+) CD patients, G vs A: P=0.0012; OR(M-H) (95% CI)=1.49 (1.17-1.90); NOD2(-) CD patients vs controls: P=0.0007; OR(M-H) (95% CI)=1.35 (1.13-1.60)). The pooled analysis of the ulcerative colitis patients vs controls also yielded a significant risk (P=0.0005; OR (95% CI)=1.52 (1.19-1.93)). These data would suggest that microbial recognition through different pathways seems to converge in the development of these polygenic bowel diseases.

Mycobacterium avium subspecies paratuberculosis and its relationship with Crohn's disease.

The hypothesis postulating that Mycobacterium avium paratuberculosis (MAP) is the cause of Crohn's disease (CD) has been circulating for many years. Advances in molecular techniques, such as polymerase chain reaction and culture methods, have enabled researchers to demonstrate that there is an association between MAP and CD. Recently, genome-wide association studies have identified novel susceptibility genes for CD, which are critical for generation of an adaptive immune response that is protective against intracellular pathogens, including M. tuberculosis infection. However, the role of MAP as a cause of CD suffered a setback with the report that administration of antimycobacterial therapy failed to lead to a sustained response in CD patients. Accordingly, this review sought neither to confirm nor refute this, but instead to survey recent literature on the role of MAP in CD.

[Influence of mutations of proteinase-activated receptors F2R/PAR1 and F2RL1/PAR2 on inflammatory bowel disease]. / Influencia de las mutaciones de los receptores activados por proteinasa F2R/PAR1 y F2RL1/PAR2 en la enfermedad inflamatoria intestinal.

BACKGROUND AND OBJECTIVE: Inflammatory bowel disease (IBD) is a polygenic complex trait. The expression and presence in biopsiae from IBD patients points to a putative role of these genes in genetic susceptibility to IBD. This is the first association study on these genes in relation with IBD. PATIENTS AND METHOD: Two polymorphisms were analyzed within F2R/PAR1 and another one mapping to F2RL1/PAR2 in 778 healthy controls and 943 IBD cases (Crohn's disease and ulcerative colitis patients from 2 cohorts from Madrid and Granada). RESULTS: No significant differences in the distribution of the PARs' polymorphisms were found. CONCLUSIONS: There is no evidence of association of the analyzed polymorphisms with IBD risk.

Open-label infliximab therapy in ulcerative colitis: a multicenter survey of results and predictors of response.

BACKGROUND/AIMS: Results of randomized controlled trials showing efficacy of infliximab in ulcerative colitis (UC) should be confirmed in clinical practice. We aimed to evaluate the efficacy and safety of infliximab in UC patients of the Madrid area, looking for clinical predictors of response. METHODOLOGY: Multicenter retrospective survey of all UC patients treated with infliximab in the region of Madrid (Spain). RESULTS: 47 UC patients were included (45% males, mean age 44 +/- 15 yrs), mean follow up of 4.7 months (range 0.5-21), and a total number of 211 infliximab infusions. Clinical response and steroid-free remission rates were, respectively, 97/42% in the 2nd week, 93/69% in the 6th week, and 80/65% at the long-term follow up (mean 8.2 months, range 3.5-21). Colectomy rate was 10.6% (five patients). Age, gender, disease duration, indication (steroid-resistance/dependence), disease severity, C-reactive protein, concomitant thiopurinic therapy or smoking habit did not influence on efficacy. Extent of the disease was the only predictive factor (p=0.02). Only 4 cases of mild adverse events were reported. CONCLUSIONS: Infliximab is effective and safe for UC. Real life clinical practice may have better outcome than showed in randomized controlled trials. Extent of the disease was the only predictive factor for clinical response in our experience.

Recomendaciones de actuación en pacientes con enfermedad de Crohn que empiezan tratamiento con adalimumab: una guía rápida / No disponible

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Influencia de las mutaciones de los receptores activados por proteinasa F2R/PAR1 y F2RL1/PAR2 en la enfermedad inflamatoria intestinal / Influence of mutations of proteinase activated receptors F2R/PAR1 and F2RL1/PAR2 on inflammatory bowel disease

FUNDAMENTO Y OBJETIVO: La enfermedad inflamatoriaintestinal (EII) es una enfermedadpoligénica compleja. Tanto la expresión dePAR1 y PAR2 como su presencia en biopsiasde pacientes con EII apuntan a un posiblepapel de estos genes en la susceptibilidadgenética a presentar EII. Éste es elprimer estudio de asociación genética quese realiza con estos genes en la EII.PACIENTES Y MÉTODO: Se analizaron mediantesondas TaqMan dos polimorfismos en el genF2R/PAR1 y otro más en el gen F2RL1/PAR2en 778 controles sanos y 943 afectados deEII (pacientes con enfermedad de Crohn ycolitis ulcerosa de Madrid y Granada).RESULTADOS: No se encontraron diferenciassignificativas en la distribución de alelosentre pacientes y controles.CONCLUSIONES: No hay evidencia de asociaciónde los polimorfismos analizados enF2R/PAR1 y F2RL1/PAR2 con modificacionesdel riesgo de presentar EII

BACKGROUND AND OBJECTIVE: Inflammatory boweldisease (IBD) is a polygenic complextrait. The expression and presence in biopsiaefrom IBD patients points to a putativerole of these genes in genetic susceptibilityto IBD. This is the first association study onthese genes in relation with IBD.PATIENTS AND METHOD: Two polymorphismswere analyzed within F2R/PAR1 and anotherone mapping to F2RL1/PAR2 in 778 healthycontrols and 943 IBD cases (Crohn’sdisease and ulcerative colitis patients from2 cohorts from Madrid and Granada).RESULTS: No significant differences in thedistribution of the PARs’ polymorphismswere found.CONCLUSIONS: There is no evidence of associationof the analyzed polymorphisms withIBD risk