Association of FcgR2a, but not FcgR3a, with inflammatory bowel diseases across three Caucasian populations.

BACKGROUND: The Fc receptors II and III (FcgR2a, and FcgR3a) play a crucial role in the regulation of the immune response. The FcgR2a*519GG and FcgR3a*559CC genotypes have been associated with several autoimmune diseases including systemic lupus erythematosus, rheumatoid arthritis, nephritis, and possibly to type I diabetes, and celiac disease. In a large multicenter, two-stage study of 6570 people, we tested whether the FcgR2a and FcgR3a genes were also involved in inflammatory bowel disease (IBD), which includes Crohn's disease (CD) and ulcerative colitis (UC). METHODS: We genotyped the FcgR2a*A519G and FcgR3a*A559C functional variants in 4205 IBD patients in six well-phenotyped Caucasian IBD cohorts and 2365 ethnically matched controls recruited from the Netherlands, Spain, and New Zealand. RESULTS: In the initial Dutch study we found a significant association of FcgR2a genotypes with IBD (P-genotype = 0.02); while the FcgR2a*519GG was more common in controls (23%) than in IBD patients (18%; odds ratio [OR] = 0.75; 95% confidence interval [CI] 0.61-0.92; P = 0.004). This association was corroborated by a combined analysis across all the study populations (Mantel-Haenszel [MH] OR = 0.84; 0.74-0.95; P = 0.005) in the next stage. The Fcgr2a*GG genotype was associated with both UC (MH-OR = 0.84; 0.72-0.97; P = 0.01) and CD (MH-OR = 0.84; 0.73-0.97; P = 0.01), suggesting that this genotype confers a protective effect against IBD. There was no association of FcgR3a*A559C genotypes with IBD, CD, or UC in any of the three studied populations. CONCLUSIONS: The FcgR2a*519G functional variant was associated with IBD and reduced susceptibility to UC and to CD in Caucasians. There was no association between FcgR3a*5A559C and IBD, CD or UC.

Decreased circulating iNKT cell numbers in refractory coeliac disease.

INTRODUCTION: A small proportion of coeliac disease (CD) patients become refractory (RCD) to a gluten-free diet (GFD) showing uncontrolled immune-mediated enteropathy. Some of these patients exhibit a high risk to develop enteropathy-associated T-cell lymphoma (EATL). AIM: The aim of the study was to find whether a lack of circulating homeostatic T cells, such as Treg, Tgammadelta(+) or iNKT cells would be associated with the development of RCD or EATL. PATIENTS AND METHODS: We investigated in a total of 137 CD patients [28 untreated, 80 responsive to GFD and 29 RCD (14 type I and 15 type II)] and 73 age-matched healthy volunteers the frequency of Treg, Tgammadelta(+) and iNKT lymphocytes by flow cytometric analysis of peripheral blood. RESULTS: Circulating Tgammadelta(+) cell and Treg frequencies in RCD were comparable to those in healthy controls. However, RCD patients had significantly reduced numbers of circulating iNKT cells, as compared to age-matched patients responding to a GFD. This reduction was similar in RCD patients with and without aberrant intraepithelial lymphocytes and in patients with EATL. Circulating iNKT cell numbers were not reduced in untreated coeliac patients. GFD treated patients had a significantly increased proportion of CD4(+) iNKT cells. CONCLUSION: Follow-up studies are necessary to determine whether CD4(+) iNKT cells control the immune response against gluten and their absence contributes to the progression to RCD and EATL.

Increasing prevalence of advanced colonic polyps in young patients undergoing colonoscopy in a referral academic hospital in Hong Kong.

AIM: To investigate the distribution and frequency of advanced polyps over eight years. METHODS: 6424 colonoscopies were reviewed during the study period 1998 to 2005. The study period was subdivided into period I: 1998 to 2001 and period II: 2002-2005. RESULTS: 1856 polyps (33% advanced polyps) and 328 CRCs were detected. The mean ages of the patients with advanced polyps and cancer were 69.2 +/- 12.0 and 71.6 +/- 13.8 years, respectively. Advanced polyps were mainly left sided (59.5%). Advanced polyps were found in patients 0.05). CONCLUSION: Advanced polyps increased significantly in the younger male group in the most recent period and there seems to be a shift towards a proximal location.

IL-1RN gene polymorphism is associated with peri-implantitis.

OBJECTIVES: Interleukin (IL)-1alpha, IL-1beta and their natural specific inhibitor IL-1 receptor antagonist (IL-1ra) play a key role in the regulation of the inflammatory response in periodontal tissues. Polymorphisms in the IL-1 gene cluster have been associated with severe adult periodontitis. We aimed to investigate the IL-1 gene cluster polymorphisms in patients with peri-implantitis. MATERIAL AND METHODS: The study included 120 North Caucasian individuals. A total of 71 patients (mean age 68 years, 76% smokers) demonstrating peri-implantitis at one or more implants as evidenced by bleeding and/or pus on probing and bone loss amounting to >3 threads on Brånemark implants and 49 controls (mean age 66 years, 45% smokers) with clinical healthy mucosa and no bone loss around the implants were recruited for the study. The titanium implants, ad modum Brånemark, had been in function for at least 2 years. Mouthwash samples were collected and used for genotyping of the bi-allelic polymorphisms IL-1A(-889), IL-1B(+3953), IL-1B(-511) and a variable number of tandem repeat IL-1RN gene polymorphisms using PCR technique. RESULTS: Significant differences were found in the carriage rate of allele 2 in the IL-1RN gene between peri-implantitis patients and controls (56.5% vs. 33.3%, respectively; odds ratios (OR) 2.6; 95% confidence interval (CI) 1.2-5.6; P=0.015). Logistic regression analysis taking smoking, gender and age into account confirmed the association between the IL-1RN allele 2 carriers and peri-implantitis (OR 3; 95% CI 1.2-7.6; P=0.02). CONCLUSIONS: Our results provide evidence that IL-1RN gene polymorphism is associated with peri-implantitis and may represent a risk factor for this disease.

TNF-857 polymorphism in Israeli Jewish patients with inflammatory bowel disease.

Tumour necrosis factor (TNF)-alpha is an important pro-inflammatory cytokine that has been implicated in the pathogenesis of inflammatory bowel disease (IBD). The promoter TNF-857 C-->T single nucleotide polymorphism (SNP) is functional through the binding to the transcription factor octamer transcription factor-1 (OCT-1). In order to investigate the frequency of this SNP in Israeli Jewish IBD patients, we analysed a cohort of well-characterized patients, 153 with Crohn's disease (CD) and 78 with ulcerative colitis (UC) and 188 healthy controls individually matched for age, sex and ethnicity. Forty-one per cent of the patients were of Ashkenazi and 48% were of non-Ashkenazi background. The remaining 11% were of mixed Ashkenazi-non-Ashkenazi background. Patients and controls were genotyped for the TNF-857 SNP by Taqman technology. Stratification for the CARD15 Arg702Trp, Gly908Arg and Leu1007fsinsC mutations took place in 136 CD patients. Carrier frequency of TNF-857T between CD and controls (36% vs. 40%; P = 0.556; OR: 1.18, 95% CI 0.74-1.88), or between UC and controls (41% vs. 37%; P = 0.743; OR: 0.85, 95% CI 0.45-1.62) did not differ significantly. Neither did stratifying for the presence of at least one of the common CARD15 mutations result in a significant difference between CD and controls. No associations were found between TNF-857T and CD phenotype as defined by the Vienna classification, perianal disease or extra-intestinal disease irrespective of CARD15 carrier status. In conclusion, it appears that TNF-857 SNP does not contribute to susceptibility of IBD, neither does it define the phenotype of CD in Israeli Jewish IBD patients.

Human leukocyte antigen-DQ2 homozygosity and the development of refractory celiac disease and enteropathy-associated T-cell lymphoma.

BACKGROUND & AIMS: Celiac disease (CD) is a common gluten-sensitive enteropathy associated with human leukocyte antigen (HLA)-DQ2 and HLA-DQ8. The aim of this study was to determine if a particular HLA-DQ subtype predisposes to complications such as refractory CD with (RCD II) or without aberrant T cells (RCD I), and enteropathy-associated T-cell lymphomas (EATL). METHODS: Molecular HLA-DQ typing was performed on 43 RCD I, 43 RCD II, and 30 EATL patients, and compared with age-matched groups of 121 patients with histologically defined uncomplicated CD and 183 healthy controls. All individuals were Dutch Caucasians and were at least 21 years of age. RESULTS: HLA-DQ2 was present in 79% of RCD I, 97.7% of RCD II, and 96.6% of EATL patients. The differences were significant when compared with 28.9% in controls but not with 91.7% in uncomplicated CD. Homozygosity for HLA-DQ2 was observed in 25.5% of RCD I, 44.1% of RCD II, and 53.3% of EATL patients vs 20.7% of uncomplicated CD patients and 2.1% of controls. HLA-DQ8 was present in 10.7% of CD, 16.2% of RCD I, 9.3% of RCD II, and 6.6% of EATL patients vs 20.2% of controls. CONCLUSIONS: Homozygosity for HLA-DQ2 is associated with RCD II and EATL. Early identification of HLA-DQ2 homozygous CD patients may help to recognize CD patients at risk for developing these severe complications.

Haplotype of prostaglandin synthase 2/cyclooxygenase 2 is involved in the susceptibility to inflammatory bowel disease.

AIM: Prostaglandin G/H synthase 2 (PTGS2 or COX2) is one of the key factors in the cellular response to inflammation. PTGS2 is expressed in the affected intestinal segments of patients with inflammatory bowel diseases (IBD). In IBD patients, non-steroidal anti-inflammatory drugs, which have been shown to reduce both the production and activity of PTGS2, may activate IBD and aggravate the symptoms. We aimed at examining genetic variants of PTGS2 that may be risk factors for IBD. METHODS: We have genotyped 291 individuals diagnosed with IBD and 367 controls from the Dutch population for the five most frequent polymorphisms of the PTGS2 gene. Clinical data were collected on all patients. DNA was extracted via normal laboratory methods. Genotyping was carried out using multiplex PCR followed by the Invader Assay and the 5' exonuclease assay (TaqMan). New polymorphism screening was performed by pre-screening with denaturing high-performance liquid chromatography, followed by fluorescent sequencing. RESULTS: Allele 5209G was weakly associated with Crohn's disease (odds ratio (OR) 1.63, 95% confidence interval (CI) 1.03-2.57), and allele 8473T with ulcerative colitis (OR 1.50, 95%CI 1.00-2.27). The haplotype including both alleles showed a strong association with IBD (OR 13.15, 95%CI 3.17-116.15). This haplotype, while rare (-0.3%) in the general population, is found more frequently in the patients (3.5%). CONCLUSION: Our data suggest that this haplotype of PTGS2 contributes to the susceptibility of IBD.

Probiotics (VSL#3) in arthralgia in patients with ulcerative colitis and Crohn's disease: a pilot study.

Arthralgia is a common extraintestinal manifestation of inflammatory bowel disease (IBD). Alterations of the immunologic regulation in the gut may contribute to the pathogenesis of arthralgia. Probiotics (VSL#3) have proven effective in the treatment of pouchitis in patients with ileal pouch anal anastomosis after panproctocolectomy for ulcerative colitis both in maintaining remission and in preventing a flare-up without side effects. The aim of this study was to determine the safety and efficacy of VSL#3 in patients with quiescent IBD who suffered from arthralgia for more than two weeks. An open-label trial was conducted using VSL#3. Pre- and post-treatment joint pain intensity were measured on the Ritchie Articular Index and visual analog scale. Disease activity of the bowel was assessed by the Truelove-Witts and the Harvey-Bradshaw scores. Sixteen of 29 patients completed the trial; in 10 of the 16 patients a statistically significant improvement was documented by the Ritchie Articular Index. No one of the patients had a relapse of intestinal disease while on probiotics. These preliminary results suggest that the probiotic mixture VSL#3 may be an alternative treatment for arthralgia in patients with IBD without inducing exacerbation of the disease. Because probiotics may be effective in the treatment of IBD as well, our results suggest that patients with active disease and arthralgia may also derive benefit from this treatment. Proper randomized controlled studies are indicated.

Toward an integrated clinical, molecular and serological classification of inflammatory bowel disease: report of a Working Party of the 2005 Montreal World Congress of Gastroenterology.

The discovery of a series of genetic and serological markers associated with disease susceptibility and phenotype in inflammatory bowel disease has led to the prospect of an integrated classification system involving clinical, serological and genetic parameters. The Working Party has reviewed current clinical classification systems in Crohn's disease, ulcerative colitis and indeterminate colitis, and provided recommendations for clinical classification in practice. Progress with respect to integrating serological and genetic markers has been examined in detail, and the implications are discussed. While an integrated system is not proposed for clinical use at present, the introduction of a widely acceptable clinical subclassification is strongly advocated, which would allow detailed correlations among serotype, genotype and clinical phenotype to be examined and confirmed in independent cohorts of patients and, thereby, provide a vital foundation for future work.

A major quantitative trait locus on mouse chromosome 3 is involved in disease susceptibility in different colitis models.

BACKGROUND & AIMS: Mice with a disrupted gene for the G-protein alpha inhibitory 2 chain ( Gnai2 -/- ) develop a spontaneous colitis resembling human inflammatory bowel disease. Disease expression differs markedly between inbred strains of mice, indicating genetic control of disease susceptibility. We performed a genome-wide screen to localize the chromosomal regions regulating disease expression. METHODS: A total of 284 F2 mice derived from resistant C57BL/6J Gnai2 -/- mice and susceptible C3H/HeN Gnai2 -/- mice were analyzed in a genome-wide screen for colitis susceptibility and severity. RESULTS: A highly significant locus on chromosome 3 (Gpdc1) contributed to colitis susceptibility and severity (likelihood ratio statistics [LRS] = 32.4; LOD score = 7; P < 1.0 x 10(-5)). The peak linkage of this locus at 62 cM colocalizes exactly with a previously identified locus controlling colitis susceptibility in interleukin-10-deficient mice. In addition, evidence for linkage with a locus on chromosome 1 (Gpdc2 ; LRS = 19.7; LOD = 4.3) was found, and the 2 loci interacted epistatically (combined LRS = 68.2). A third locus (Gpdc3) was found on chromosome 9 and this locus interacted epistatically with a locus on chromosome 7, which by itself did not have an effect on the trait. CONCLUSIONS: The identification of a major locus on chromosome 3 that controls susceptibility to spontaneous colitis in 2 different gene-knockout models indicates that this locus harbors a gene(s) that plays a key role in maintaining mucosal homeostasis. Identification of this gene(s) may contribute to further understanding of the mechanisms underlying human inflammatory bowel disease.

CARD15 mutations in patients with Crohn's disease in a homogeneous Spanish population.

OBJECTIVES: Three mutations in CARD15 have been repeatedly shown to be involved in Crohn's disease susceptibility, mainly in Caucasian individuals. However, those findings were not replicated in all populations studied so far. In this work, we studied the role of CARD15 mutations in a relatively homogeneous population from the Northwest of Spain, Galicia. METHODS: One hundred and sixty-five patients with Crohn's disease and a similar number of healthy controls were recruited from a single center in Galicia. All individuals were genotyped for the three main Crohn's disease associated CARD15 variants (R702W, G908R, and 1007fs). Association analyses were performed to study the influence of those mutations on Crohn's disease overall and on clinical subphenotypes. RESULTS: The allele frequencies of CARD15 variants were lower in this population than in most of the European populations studied so far. G908R and 1007fs were significantly associated with overall susceptibility to Crohn's disease. However, these associations were lost after stratification to clinical subgroups, probably due to the small number of cases in these subgroups. Significant associations were found between G908R and 1007fs and the behavior of Crohn's disease, but they were due to the influence of years of disease on the behavior of the disease rather than being the result of a direct effect of these mutations on disease behavior. CONCLUSIONS: The CARD15 variants G908R and 1007fs, but not R702W, are associated with susceptibility to Crohn's disease in Galicia. Interestingly, the frequency of these mutations appears to be lower than in other Caucasian populations studied so far.

Association of tumor necrosis factor genetic polymorphism with chronic atrophic gastritis and gastric adenocarcinoma in Chinese Han population.

AIM: To investigate the association of TNF polymorphisms with chronic atrophic gastritis (CAG) and gastric adenocarcinoma in Chinese Han patients. METHODS: The TNFa-e 5 microsatellites and 3 RFLP sites were typed using PCR technique, followed by high-voltage denaturing PAGE with silver staining and restriction enzyme digestion respectively in specimens from 53 patients with CAG and 56 patients with gastric adenocarcinoma and 164 healthy controls. The PCR products were cloned and sequenced. RESULTS: The frequency of TNF-beta Ncol*1/2 genotype was higher in patients with chronic atrophic gastritis than in healthy controls, but no significant difference was observed (60.38% vs 46.34%, P=0.076). The frequency of TNa10 allele was significantly higher in patients with chronic atrophic gastritis than in healthy controls (19.81% vs 11.89%, P=0.04). However, it did not relate to age, gender, atrophic degree or intestinal metaplasia in patients with chronic atrophic gastritis. The frequency of TNF-beta Ncol*1/2 and d2/d6 genotypes were significantly higher in patients with gastric adenocarcinoma than in healthy individuals (P>0.05). However, TNF-beta Ncol*1/2 and d2/d6 genotypes did not relate to age, gender, grade of differentiation and clinicopathologic stage in patients with gastric adenocarcinoma. The frequency of TNFa6b5c1 haplotype homozygote was significantly lower in patients with gastric adenocarcinoma than in healthy controls (1.79% vs 15.85%, P=0.006). CONCLUSION: TNFa10 allele may be a risk factor for chronic atrophic gastritis. TNF-beta Ncol*1/2 and d2/d6 genotypes are associated with the susceptibility to gastric adenocarcinoma, whereas TNFa6b5c1 haplotype homozygote may contribute to the resistance against gastric adenocarcinoma.

IBD1 and IBD3 determine location of Crohn's disease in the Spanish population.

BACKGROUND: Crohn's disease is a heterogeneous disease from both genetic and clinical points of view. AIMS: To look for associations between distinct genetic polymorphisms and clinical subgroups of the disease. SUBJECTS: A total of 210 patients and 343 healthy control subjects, all adult, unrelated, white, Spanish individuals. METHODS: DNA was purified from peripheral blood samples and was typed by sequence-specific oligonucleotide polymerase chain reaction (PCR) method for human leukocyte antigen (HLA)-DRB1 alleles (IBD3) and by allele-specific PCR for NOD2/CARD15 (IBD1) polymorphisms. RESULTS: NOD2/CARD15 mutations and HLA-DRB1*07 confer susceptibility only to the ileal location of the disease, whereas HLA-DRB1*0103 is associated only with the colonic location of the disease. The IBD3 effect was overshadowed by IBD1 mutations when present. CONCLUSION: The studied genetic polymorphisms of Crohn's disease basically determine the location of the disease and, only secondarily, the clinical form of the disease. This appears to be true for both inflammatory bowel diseases as HLA-DRB1*0103 is associated both with colonic Crohn's disease and ulcerative colitis.

Toll-like receptors and NOD/CARD proteins: pattern recognition receptors are key elements in the regulation of immune response.

The magnitude of the response to a specific immunogen such as an infectious agent is the result of a complex interaction between genetic and environmental factors. For example, in intestinal inflammation, the inflammatory response appears to be regulated by the indigenous microflora of the gut, by receptors in epithelial cells and antigen-presenting cells in the intestinal mucosa, and by immunologic factors. Recent evidence suggests that genetic variants of human immunomodulating genes influence the susceptibility to and severity of infectious diseases and the subsequent clinical outcome of disease. This review will focus on recently identified pattern recognition receptors which are located on innate immune and epithelial cells, and recognize pathogen-associated molecular patterns. The binding of specific pathogen-associated molecular patterns to these receptors results in the activation of a signal transduction pathway through nuclear factor (NF)-kappaB which leads to either enhanced or inhibited immune responses that modify the production of inflammatory effectors, such as cytokines. This article reports on the identification and functional characterization including the discovery of mutants which completely abolish NF-kappaB signal transduction of pattern recognition receptors, such as the extracellular Toll-like receptors and the intracellular nucleotide oligomerization domain/caspase recruitment domain (NOD/CARD) receptors, as well as their role in clinical disease. Knowledge of pattern recognition receptors such as Toll-like receptors and NOD/CARD intracytoplasmic proteins, including their functions and their downstream signaling pathways, may provide a new molecular basis for preventing or blocking inflammation associated with pathogenic microorganisms. This could direct a new focus for better and more specific therapeutic treatments based on immuno-intervention that can promise a better quality of life for those suffering from chronic disturbances of the immune response.

Treatment of Extraintestinal Manifestations in Inflammatory Bowel Disease.

Extraintestinal manifestations (EIM) of inflammatory bowel disease (IBD) occur rather frequently and may be found in up to 30% of patients. However, surprisingly few randomized, controlled studies have been conducted that were specifically aimed at the treatment of EIM of IBD patients. Therefore, most therapies of EIM are empiric or deduced from studies in populations with other type of patients. EIM may be associated with active IBD. Treatment of active IBD is, therefore, the mainstay of treatment of EIM. Lifestyle modification as a means of therapy is a recent subject of study in chronic conditions, such as IBD. Based on epidemiologic and experimental findings, EIM of various tracts can be modified by optimizing alimentary intake, refraining from sedentary lifestyle, and adapting smoking habits. Not many new drugs for treatment of EIM have been developed during the past few years; the role of infliximab has been extended in particular in Crohn's disease-related EIM. Careful consideration of prescribed drugs remains necessary due to potential interaction with the course of IBD.

Polymorphisms at the TNF locus in Chinese Han population.

One hundred sixty-four unrelated healthy individuals from Chinese Han population were investigated in order to define the distribution of eight polymorphic loci within the tumor necrosis factor (TNF) gene cluster and determine their relationship between the high polymorphic microsatellite TNFa, b, d, and other elements. The cloning and sequencing for five microsatellites were simultaneously done. In this study, the distribution of TNF alleles apparently vary from other ethnic groups. A new allele was detected and confirmed. It should be emphasized that a very strong association between TNFd8 and TNFe4 is reported and d8e4 haplotype appears to be specific to the population studied. In addition, five extended haplotypes were established in this population: a6b5c1d8e4TNF308-1TNF-betaNco1-1TNFAspH1-2, a2b1c2d5e1TNF308-1TNF-betaNco1-2TNFAspH1-2, a11b4c1d4e3TNF308-1TNF-betaNco1-2TNFAspH1-1, a10b4c1d4e3TNF308-1TNF-betaNco1-2TNFAspH1-1, and a2b3c1d2e3TNF308-2TNFAspH1-2. Data suggest that important ethnic differences may exist and that it is a necessary initiative for further research.

CARD15 gene and the classification of Crohn's disease.

An insertion mutation at nucleotide 3020 (3020insC) in the CARD15 gene, originally reported as NOD2, has been strongly associated with Crohn's disease. The CARD15 G2722C missense mutation was also shown to be associated with this disease. We studied 130 Dutch Crohn's disease patients, with a median follow up of 9.2 years, in relation to the Vienna classification, and 152 ethnically matched healthy controls. We confirm reports that the CARD15 3020insC mutation increases the susceptibility to Crohn's disease, but we do not confirm this relationship for CARD15 G2722C. Our findings suggest that these mutations are not a marker of a particular form of Crohn's disease according to the Vienna classification. Whether the CARD153020insC and CARD15 G2722C mutations are responsible for a different etiopathogenic mechanism in a subgroup of patients remains to be studied.

Extraintestinal Complications of Inflammatory Bowel Disease.

Extraintestinal complications of inflammatory bowel disease (IBD) are often secondary to the underlying disease. Therefore, the first priority is to get active IBD into remission with medications, since surgery for IBD is not indicated for the treatment of extraintestinal complications. Symptoms of extraintestinal complications usually can be treated with simple agents; the treatment of patients with refractory symptoms and the use of more complex drug regimens should be done in cooperation with specialists on affected organ systems. Careful consideration of prescribed drugs is necessary because they may negatively influence the course of IBD.