Familial aggregation in inflammatory bowel disease: Is it genes or environment?

Differences of clinical phenotype between familial and sporadic Crohn's disease in East China

PURPOSE

Family history is one of the strongest risk factors for inflammatory bowel diseases (IBD) while studies about the clinical phenotype of familial IBD are limited. This study aimed to compare the phenotypic features of familial Crohn's disease (CD) with sporadic CD.

METHODS

Familial CD was defined as CD patients having one or more first, second, third, fourth degree, or above relatives with CD. Sporadic CD patients hospitalized during the same period were matched 1:3 by age and gender. Differences in clinical characteristics, phenotype distribution, extraintestinal manifestations, and complications at diagnosis, as well as treatment regimen and surgery, were compared between familial and sporadic CD.

RESULTS

The familial CD was associated with a higher rate of past appendectomy history (P = 0.009), more intestinal perforation at onset (P = 0.012), more MRI results of anal lesion (P = 0.023), and gastrointestinal perforation (P = 0.040) at diagnosis, higher rate of past intestinal surgery history (P = 0.007), more number of intestinal surgeries (P = 0.037), longer duration of follow-up (P = 0.017), lower rate of taking biologicals for current maintenance (P = 0.043), lower tendency to upgrade to biologicals during follow-up (P = 0.013), higher possibility to experience gastrointestinal obstruction (P = 0.047), and abdominal abscess during follow-up (P = 0.045).

CONCLUSION

Familial CD is associated with a more aggressive clinical phenotype.

Bidirectional association between inflammatory bowel disease and depression among patients and their unaffected siblings

BACKGROUND AND AIM

Approximately 30% of inflammatory bowel disease (IBD) patients develop depression. Conversely, several studies reported increased IBD risk among patients with depression. Such bidirectional relationship has not been reported within one representative cohort, nor investigated among patients' family members. These associations may further implicate the gut-brain axis in IBD.

METHODS

We conducted parallel retrospective cohort analyses to investigate depression risk among IBD patients and their unaffected siblings, and IBD risk among patients with depression and their unaffected siblings using the Taiwanese National Health Insurance Research Database. Individuals were followed up to 11 years for new-onset depression or IBD. Controls were matched to unaffected siblings based on predefined characteristics.

RESULTS

To investigate depression risk among IBD - 422 IBD patients, 537 unaffected siblings, and 2148 controls were enrolled. During follow-up, 78 (18.5%) IBD patients, 26 (4.8%) unaffected siblings, and 54 (2.5%) controls developed depression. Adjusted odds ratios (ORs) for depression among IBD patients and unaffected siblings were 9.43 (95% CI 6.43-13.81; P < 0.001) and 1.82 (95% CI 1.14-2.91; P = 0.013), respectively. To investigate IBD risk among depression - 25 552 patients with depression, 26 147 unaffected siblings, and 104 588 controls were enrolled. During follow-up, 18 (0.70/1000) depression patients, 25 (0.96/1000) unaffected siblings, and 58 (0.55/1000) controls developed IBD. ORs for IBD among depression patients and unaffected siblings were 1.87 (95% CI 1.07-3.26; P = 0.028) and 1.69 (95% CI 1.05-2.69; P = 0.029), respectively.

CONCLUSIONS

This population-based study elucidates bidirectional association between IBD and depression. Elevated risks for either disease among patients and their unaffected siblings suggest shared etiologic contributors, offering novel insight into the gut-brain axis' influence in IBD pathophysiology.

Detecting pathogenic variants in autoimmune diseases using high-throughput sequencing

Sequencing the first human genome in 2003 took 15 years and cost $2.7 billion. Advances in sequencing technologies have since decreased costs to the point where it is now feasible to resequence a whole human genome for $1000 in a single day. These advances have allowed the generation of huge volumes of high‐quality human sequence data used to construct increasingly large catalogs of both population‐level and disease‐causing variation. The existence of such databases, coupled with a high‐quality human reference genome, means we are able to interrogate and annotate all types of genetic variation and identify pathogenic variants for many diseases. Increasingly, sequencing‐based approaches are being used to elucidate the underlying genetic cause of autoimmune diseases, a group of roughly 80 polygenic diseases characterized by abnormal immune responses where healthy tissue is attacked. Although sequence data generation has become routine and affordable, significant challenges remain with no gold‐standard methodology to identify pathogenic variants currently available. This review examines the latest methodologies used to identify pathogenic variants in autoimmune diseases and considers available sequencing options and subsequent bioinformatic methodologies and strategies. The development of reliable and robust sequencing and analytic workflows to detect pathogenic variants is critical to realize the potential of precision medicine programs where patient variant information is used to inform clinical practice.

Characteristics of inflammatory bowel disease in patients of Roma/Gypsy ethnicity. A case-control study

BACKGROUND

Peculiarities of inflammatory bowel disease (IBD) have been explored in ethnic groups, such as Asians, Hispanics, and Afro-Americans, but not in other ethnic minorities, such as Roma/Gypsies.

METHODS

In a retrospective, hospital-based study, all adult Roma/Gypsy patients included in the IBD databases of seven Spanish centres were identified as cases. For each Roma/Gypsy patient, a Caucasian patient, matched for several demographic features, was searched as a control. Data on phenotypic features, therapeutic requirements, and familial aggregation were recorded.

RESULTS

Sixty-eight Roma/Gypsy patients were identified, 29 of them being women. The mean age at diagnosis of IBD was 24.9±9.5years, and the mean time elapsed since diagnosis was 96.6±72.2months. Roma/Gypsy IBD patients showed a significantly higher rate of familial aggregation (43%) than their Caucasian controls (9%) (p=0.00001). CD in Roma/Gypsies had more often a complicated pattern (mainly penetrating) while UC patients showed a marked trend to more often developing extraintestinal manifestations. In addition, Roma/Gypsy IBD patients had a somewhat greater need for immunosuppressants, biological agents or surgery.

CONCLUSIONS

These are the first data on IBD in Roma/Gypsy patients. Familial aggregation is the most prominent feature in these patients, suggesting a predominant role of genetics in its pathogenesis.

The oral microbiome

The human microbiome is receiving a great deal of attention as its role in health and disease becomes ever more apparent. The oral microbiome, perhaps due to the ease with which we can obtain samples, is arguably the most well-studied human microbiome to date. It is obvious, however, that we have only just begun to scratch the surface of the complex bacterial and bacterial–host interactions within this complex community. Here, we describe the factors which are known to influence the development of the seemingly globally conserved, core, oral microbiome and those which are likely to be responsible for the observed differences at the individual level. We discuss the paradoxical situation of maintaining a stable core microbiome which is at the same time incredibly resilient and adaptable to many different stresses encountered in the open environment of the oral cavity. Finally, we explore the interactions of the oral microbiome with the host and discuss the interactions underlying human health and disease.

The Human Salivary Microbiome Is Shaped by Shared Environment Rather than Genetics: Evidence from a Large Family of Closely Related Individuals

The human microbiome is affected by multiple factors, including the environment and host genetics. In this study, we analyzed the salivary microbiomes of an extended family of Ashkenazi Jewish individuals living in several cities and investigated associations with both shared household and host genetic similarities. We found that environmental effects dominated over genetic effects. While there was weak evidence of geographical structuring at the level of cities, we observed a large and significant effect of shared household on microbiome composition, supporting the role of the immediate shared environment in dictating the presence or absence of taxa. This effect was also seen when including adults who had grown up in the same household but moved out prior to the time of sampling, suggesting that the establishment of the salivary microbiome earlier in life may affect its long-term composition. We found weak associations between host genetic relatedness and microbiome dissimilarity when using family pedigrees as proxies for genetic similarity. However, this association disappeared when using more-accurate measures of kinship based on genome-wide genetic markers, indicating that the environment rather than host genetics is the dominant factor affecting the composition of the salivary microbiome in closely related individuals. Our results support the concept that there is a consistent core microbiome conserved across global scales but that small-scale effects due to a shared living environment significantly affect microbial community composition.

Previous research shows that the salivary microbiomes of relatives are more similar than those of nonrelatives, but it remains difficult to distinguish the effects of relatedness and shared household environment. Furthermore, pedigree measures may not accurately measure host genetic similarity. In this study, we include genetic relatedness based on genome-wide single nucleotide polymorphisms (SNPs) (rather than pedigree measures) and shared environment in the same analysis. We quantify the relative importance of these factors by studying the salivary microbiomes in members of a large extended Ashkenazi Jewish family living in different locations. We find that host genetics plays no significant role and that the dominant factor is the shared environment at the household level. We also find that this effect appears to persist in individuals who have moved out of the parental household, suggesting that aspects of salivary microbiome composition established during upbringing can persist over a time scale of years.

Gastrointestinal neuroendocrine peptides/amines in inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic recurrent condition whose etiology is unknown, and it includes ulcerative colitis, Crohn’s disease, and microscopic colitis. These three diseases differ in clinical manifestations, courses, and prognoses. IBD reduces the patients’ quality of life and is an economic burden to both the patients and society. Interactions between the gastrointestinal (GI) neuroendocrine peptides/amines (NEPA) and the immune system are believed to play an important role in the pathophysiology of IBD. Moreover, the interaction between GI NEPA and intestinal microbiota appears to play also a pivotal role in the pathophysiology of IBD. This review summarizes the available data on GI NEPA in IBD, and speculates on their possible role in the pathophysiology and the potential use of this information when developing treatments. GI NEPA serotonin, the neuropeptide Y family, and substance P are proinflammatory, while the chromogranin/secretogranin family, vasoactive intestinal peptide, somatostatin, and ghrelin are anti-inflammatory. Several innate and adaptive immune cells express these NEPA and/or have receptors to them. The GI NEPA are affected in patients with IBD and in animal models of human IBD. The GI NEPA are potentially useful for the diagnosis and follow-up of the activity of IBD, and are candidate targets for treatments of this disease.

Abnormal differentiation of stem cells into enteroendocrine cells in rats with DSS-induced colitis

The present study aimed to determine whether there is an association between abnormalities in enteroendocrine cells in dextran sulfate sodium (DSS)-induced colitis and the clonogenic and/or proliferative activities of stem cells. A total of 48 male Wistar rats were divided into four groups. Animals in the control group were provided with normal drinking water, whereas DSS colitis was induced in the remaining three groups. The rats with DSS-induced colitis were randomized into the following three groups: i) DSS group, which received 0.5 ml 0.5% carboxymethyl cellulose (CMC; vehicle); ii) DSS-G group, which was treated with 3-[(dodecylthiocarbonyl)-methyl]-glutarimide at 20 mg/kg body weight in 0.5% CMC; and iii) DSS-Q group, which was treated with dehydroxymethylepoxyquinomicin at 15 mg/kg body weight in 0.5% CMC. Treatments were administered intraperitoneally twice daily for 5 days in all groups. Subsequently, tissue samples from the colon were stained with hematoxylin-eosin, or immunostained for chromogranin A (CgA), Musashi 1 (Msi1), Math-1, neurogenin 3 (Neurog3) and neurogenic differentiation D1 (NeuroD1). The densities of CgA, Msi1-, Math-1-, Neurog3- and NeuroD1-immunoreactive cells were determined. DTCM-G, and DHMEQ ameliorated the inflammation in DSS-induced colitis. The density of CgA-, Neurog3- and NeuroD1-immunoreactive cells was significantly higher in the DSS group compared with in the control group, and the density of CgA cells was correlated with the densities of Neurog3- and NeuroD1-immunoreactive cells. There were no significant differences in the densities of Msi1- and Math-1-immunoreactive cells among the four experimental groups. The elevated densities of enteroendocrine cells detected in DSS-induced colitis may be due to the increased differentiation of early enteroendocrine progenitors during secretory lineage. It is probable that the DSS-induced inflammatory processes trigger certain signaling pathways, which control differentiation of the stem-cell secretory lineage into mature enteroendocrine cells.

A cross-sectional survey of multi-generation inflammatory bowel disease consanguinity and its relationship with disease onset

Background\Aim: Consanguinity influences the phenotypic variations of some hereditary and immune-mediated disorders, including inflammatory bowel disease. This study estimated the prevalence of consanguinity among the ancestors of patients with inflammatory bowel disease and examined the effect of various consanguinity levels on inflammatory bowel disease onset.

PATIENTS AND METHODS

Patients with inflammatory bowel disease who were seen at two gastroenterology outpatient clinics were consecutively recruited and surveyed for demographics, disease onset, and presence of ancestral consanguinity within three generations. The prevalence of different consanguinity levels was calculated. The association between age at inflammatory bowel disease onset and consanguinity was examined.

RESULTS

Two hundred seventeen patients were recruited. The mean age, mean age at diagnosis, and mean illness duration were 32.9 ± 13.4, 18.6 ± 11.5, and 8.6 ± 7.7 years, respectively. Of the cohort, 53.5% were women, and 74.2% were native Saudis. Cigarette smoking was reported in 17.1%; 51% had Crohn's disease, while the remaining patients had ulcerative colitis. A family history of inflammatory bowel disease was reported in 29.5% of patients; consanguinity within three generations was reported in 57.6%. Consanguinity in more than one generation was reported in 38.7%; 17.5% had consanguinity in three consecutive generations. There was no association between inflammatory bowel disease onset and multi-generation consanguinity, but there was an association with disease subtype in favor of ulcerative colitis (b coefficient = 7.1 [95% confidence interval = 4.1, 10]).

CONCLUSIONS

Consanguinity is extremely common among Saudi patients with inflammatory bowel disease but does not seem to influence age at disease onset. Genetic studies are needed to further clarify the effect of consanguinity on disease behavior.

Abnormalities in endocrine and immune cells are correlated in dextran‑sulfate‑sodium‑induced colitis in rats

The interaction between the gut hormones and the immune system has been suggested to serve an important role in the pathophysiology of inflammatory bowel disease. The aims of the present study were to elucidate the possible abnormalities in the colonic endocrine cells in rats with dextran sodium sulfate (DSS)-induced colitis, and to determine whether they are correlated with alterations in the immune cells. A total of 24 male Wistar rats were divided into two groups: Control and DSS-induced colitis. Colonic tissues were harvested via postmortem laparotomy from all of the animals at the end of the experimental period, and fixed and sectioned for histology. The colonic endocrine and immune cells in those tissue samples were immunostained and their densities quantified by computerized image analysis. The densities of chromogranin A, serotonin, peptide YY and oxyntomodulin cells were significantly higher, and those of pancreatic peptide and somatostatin cells were lower in rats with DSS-induced colitis than in the controls. The densities of mucosal leukocytes, T and B lymphocytes, macrophages/monocytes, and mast cells were significantly higher than in the controls, and these changes were closely associated with the aforementioned changes in all endocrine cell types. These observations indicate an interaction between intestinal hormones and the immune system as represented by immune cells.

Associations of fucosyltransferase 2 gene polymorphism with susceptibility to inflammatory bowel disease: A meta-analysis

AIM

To explore the relationship between fucosyltransferase 2 (FUT2) A385T and G428A gene polymorphisms and susceptibility to inflammatory bowel disease(IBD).

METHODS

Databases including Embase, PubMed, EBM Reviews, Ovid, Springer, CNKI, and WanFang were searched for articles evaluating the relationship between FUT2 gene polymorphism and susceptibility to IBD. Available data were extracted and quality of the included studies was evaluated. Meta-analysis was conducted by using Review Manager 5.3 and Stata 12.0. Begg's funnel plot was used to assess the published bias of articles.

RESULTS

Totally 10 articles were included, including 3682 cases and 5470 controls. Each genetic model in ulcerative colitis (UC) was as follows: dominant model [(AA + AT) vs TT: OR = 0.60 (95%CI: 0.43-0.85); (GG + GA) vs AA: OR = 0.51 (95%CI: 0.38-0.70)]; recessive model [(AT + TT) vs AA: OR = 0.96 (95%CI: 0.73-1.25); (GA + AA) vs GG: OR = 0.70 (95%CI: 0.36-1.36)]; codominant model [AA vs TT: OR = 1.02 (95%CI: 0.82-1.27); GG vs AA: OR = 1.23 (95%CI: 0.93-1.63)]; allele genetic model [A vs T: OR = 1.06 (95%CI: 0.95-1.17); G vs A: OR = 1.18 (95%CI: 0.68-2.04)]. Each genetic model in Crohn's disease (CD) was as follows: dominant model [(AA + AT) vs TT: OR = 0.60 (95%CI: 0.43-0.85); (GG + GA) vs AA: OR = 0.51 (95%CI: 0.38-0.70)]; recessive model [(AT + TT) vs AA]: OR = 0.99 (95%CI: 0.73-1.35); (GA + AA) vs GG: OR = 1.49 (95%CI: 1.17-1.91)]; codominant model [AA vs TT: OR = 1.37 (95%CI: 0.95-1.98); GG vs AA: OR = 0.46 (95%CI: 0.33-0.65)]; allele genetic model [G vs A: OR = 0.67 (95%CI: 0.57-0.79); G vs A: OR = 0.67 (95%CI: 0.57-0.79)].

CONCLUSION

FUT2 A385T and G428A polymorphisms are not significantly related with IBD. In Asians, the TT on A385T confers a significant risk for developing CD. FUT2 G428A polymorphism is related with CD, and the allele gene A confers a risk for developing CD.

Influence of a Positive Family History on the Clinical Course of Inflammatory Bowel Disease

BACKGROUND AND AIMS

Previous studies on the difference in phenotypes and disease course between familial and sporadic inflammatory bowel disease (IBD) have been controversial, although family history is considered to increase the risk of developing IBD.

METHODS

The influence of family history on phenotype and disease course of IBD was analysed in 2805 Korean patients with Crohn's disease (CD) and 3266 with ulcerative colitis (UC). Familial IBD was defined as the existence of one or more first-, second- and/or third-degree relatives affected with CD or UC.

RESULTS

A positive family history of IBD was noted in 191 patients with CD (6.8%) and 212 patients with UC (6.5%). In the patients with CD, the probability of anti-TNF use was higher in the familial cases than in the sporadic cases (56.3 vs 43.4%, respectively, at 10 years, p = 0.019). When analysed after excluding patients who had undergone intestinal resection within 1 year of diagnosis, the cumulative probability of intestinal resection was higher in the familial cases than in the sporadic cases (55.0 vs 32.2%, respectively, at 10 years; p = 0.007). In multivariate analysis, family history was an independent risk factor for the time to first intestinal resection in patients with CD (hazard ratio: 1.61, 95% confidence interval: 1.13-2.29; p = 0.009). In patients with UC, younger age at diagnosis and more females were observed in the familial cases (p < 0.001).

CONCLUSIONS

The present study suggests the possibility of a more aggressive clinical course of CD in familial compared with sporadic cases.

Susceptibility to Ulcerative Colitis and Genetic Polymorphisms of A251G SOD1 and C-262T CAT

BACKGROUND

Reactive oxygen species can attack and damage almost every molecule found in living cells, including proteins, carbohydrates, lipids, and DNA. For this reason, their production is normally tightly controlled. Among the most important defenses against these radicals are the superoxide dismutase (SOD) enzymes and catalase (CAT). Increasing attention has been given to the role of reactive oxygen metabolites in the pathogenesis of ulcerative colitis (UC), which is defined as an idiopathic and chronic intestinal inflammation. Accordingly, we hypothesized a relation between genetic polymorphisms in the two antioxidant enzymes SOD1 A251G (rs2070424) and CAT C-262T (rs1001179) and the risk of UC.

METHODS

The present case-control study included 109 UC patients (46 males and 50 females) and 186 (67 males and 119 females) gender-matched healthy controls. Genotyping was done by the PCR-RFLP method.

RESULTS

After adjusting for age and gender, a significant association was observed between the AG+GG genotypes of SOD1 A251G polymorphism (vs. AA genotype) and risk of UC (OR=0.29, 95% CI: 0.10-0.86, P= 0.025) after adjusting for age and gender. Our statistical analysis revealed that the CAT C-262T polymorphism did not associate with the risk of UC before and/or after adjusting for age and gender.

CONCLUSIONS

Based on the present statistical analysis, the G allele of the SOD1 A251G polymorphism decreases the risk of UC, thus it might be assumed that the G allele has a protective role.

The role of the neuropeptide Y (NPY) family in the pathophysiology of inflammatory bowel disease (IBD)

Inflammatory bowel disease (IBD) includes three main disorders: ulcerative colitis, Crohn's disease, and microscopic colitis. The etiology of IBD is unknown and the current treatments are not completely satisfactory. Interactions between the gut neurohormones and the immune system are thought to play a pivot role in inflammation, especially in IBD. These neurohormones are believed to include members of the neuropeptide YY (NPY) family, which comprises NPY, peptide YY (PYY), and pancreatic polypeptide (PP). Understanding the role of these peptides may shed light on the pathophysiology of IBD and potentially yield an effective treatment tool. Intestinal NPY, PYY, and PP are abnormal in both patients with IBD and animal models of human IBD. The abnormality in NPY appears to be primarily caused by an interaction between immune cells and the NPY neurons in the enteric nervous system; the abnormalities in PYY and PP appear to be secondary to the changes caused by the abnormalities in other gut neurohormonal peptides/amines that occur during inflammation. NPY is the member of the NPY family that can be targeted in order to decrease the inflammation present in IBD.

LOWER LEVELS OF VITAMIN D CORRELATE WITH CLINICAL DISEASE ACTIVITY AND QUALITY OF LIFE IN INFLAMMATORY BOWEL DISEASE

Background - Inflammatory bowel disease, comprising Crohn's disease and ulcerative colitis, is a group of debilitating conditions associated with deregulated mucosal immune response. Vitamin D has been implicated in immune response and gastrointestinal function. Objectives - To investigate the correlation between serum vitamin D levels and disease activity and quality of life in patients with inflammatory bowel disease. Methods - This cross-sectional study enrolled ambulatory patients with inflammatory bowel disease and assessed clinical disease activity and quality of life (Short Inflammatory Bowel Disease Questionnaire [SIBDQ]). Vitamin D levels were determined via serum 25-hydroxyvitamin D measurement; deficiency was defined as values <20 ng/mL. Statistical analysis was performed with SPSS vs 20.0. Results - A total of 76 patients were enrolled, 19 with ulcerative colitis (25%) and 57 with Crohn's disease (75%). Overall, mean serum 25-hydroxyvitamin D levels were low (26.0±10.0 ng/mL), while those in patients with Crohn's disease were significantly lower than ulcerative colitis (24.6±8.0 vs 30.0±12.5 ng/mL; P=0.032). Vitamin D deficiency was found in 30% of patients. Patients who were in clinical remission were found to have higher levels of vitamin D than those who were not in remission (28.0±10.3 vs 21.6±6.0 ng/mL, P=0.001). Inflammatory bowel disease patients with SIBDQ scores <50 were found to have significantly lower mean vitamin D levels compared with patients who had SIBDQ scores ≥50 (23.4±6.9 vs 27.9±10.8 ng/mL, P=0.041). Conclusions - A high proportion of patients with inflammatory bowel disease were vitamin D deficient, particularly patients with Crohn's disease. Both clinical disease activity and quality of life correlated significantly with lower levels of vitamin D, illustrating a clear need for supplementation in patients with inflammatory bowel disease.

Genetic sharing and heritability of paediatric age of onset autoimmune diseases

Autoimmune diseases (AIDs) are polygenic diseases affecting 7-10% of the population in the Western Hemisphere with few effective therapies. Here, we quantify the heritability of paediatric AIDs (pAIDs), including JIA, SLE, CEL, T1D, UC, CD, PS, SPA and CVID, attributable to common genomic variations (SNP-h(2)). SNP-h(2) estimates are most significant for T1D (0.863±s.e. 0.07) and JIA (0.727±s.e. 0.037), more modest for UC (0.386±s.e. 0.04) and CD (0.454±0.025), largely consistent with population estimates and are generally greater than that previously reported by adult GWAS. On pairwise analysis, we observed that the diseases UC-CD (0.69±s.e. 0.07) and JIA-CVID (0.343±s.e. 0.13) are the most strongly correlated. Variations across the MHC strongly contribute to SNP-h(2) in T1D and JIA, but does not significantly contribute to the pairwise rG. Together, our results partition contributions of shared versus disease-specific genomic variations to pAID heritability, identifying pAIDs with unexpected risk sharing, while recapitulating known associations between autoimmune diseases previously reported in adult cohorts.

Experimental evidence of heparanase, Hsp70 and NF-κB gene expression on the response of anti-inflammatory drugs in TNBS-induced colonic inflammation

AIM

Etiopathogenesis of inflammatory bowel disease is unclear and results from a complex interplay of genetic, microbial, environmental and immune factors. Elucidating the mechanisms that drive IBD depends on the detailed characterization of human inflammatory mediators in animal models. Therefore, we studied how intestinal inflammation affects heparanase, NF-κB and Hsp70 gene expression in rats, and if current intestinal anti-inflammatory drugs (sulphasalazine, prednisolone and azathioprine) act on these expressions. Moreover, we investigated the relationships among these genes with colonic cytokines levels (IL-1β, TNF-α, IL-6, INF-γ and IL-10) and oxidative stress that have fundamental role in IBD.

MATERIAL AND METHODS

Macroscopic parameters (diarrhea, extension of lesion, colonic weight/length ratio and damage score), biochemical markers (myeloperoxidase and alkaline phosphatase activities, and glutathione, IL-1β, TNF-α, IL-6, INF-γ and IL-10 levels), gene expressions (heparanase, NF-κB and Hsp70), and microscopic evaluations (optic, electronic scanning and transmission microscopic) were performed in rats.

KEY FINDINGS

Expression of heparanase, Hsp70 and NF-κB and oxidative stress were increased by inflammatory process and differentially modulated by sulphasalazine, prednisolone and azathioprine treatments. Protective effects of drugs were also related to differential modulation of cytokine changes induced by inflammatory process, showing different mechanisms to control inflammation.

SIGNIFICANCE

Heparanase, NF-κB and Hsp70 gene expression participate in the inflammatory response induced by TNBS and represent pharmacological targets of the intestinal anti-inflammatory drugs. In addition, current drugs used to treat IBD (sulphasalazine, prednisolone and azathioprine) differentially modulate heparanase, NF-κB and Hsp70 gene expression, cytokine production and oxidative stress.

Contribution of the IL-17/IL-23 axis to the pathogenesis of inflammatory bowel disease

Inflammatory bowel diseases (IBDs) are chronic disorders of modern society, requiring management strategies aimed at prolonging an active life and establishing the exact etiology and pathogenesis. These idiopathic diseases have environmental, genetic, immunologic, inflammatory, and oxidative stress components. On the one hand, recent advances have shown that abnormal immune reactions against the microorganisms of the intestinal flora are responsible for the inflammation in genetically susceptible individuals. On the other hand, in addition to T helper cell-type (Th) 1 and Th2 immune responses, other subsets of T cells, namely regulatory T cells and Th17 maintained by IL-23 are likely to develop IBD. IL-23 acts on innate immune system members and also facilitates the expansion and maintenance of Th17 cells. The IL-17/IL-23 axis is relevant in IBD pathogenesis both in human and experimental studies. Novel biomarkers of IBD could be calprotectin, microRNAs, and serum proinflammatory cytokines. An efficient strategy for IBD therapy is represented by the combination of IL-17A and IL-17F in acute IL-17A knockout TNBS-induced colitis, and also definite decrease of the inflammatory process in IL-17F knockout, DSS-induced colitis have been observed. Studying the correlation between innate and adaptive immune systems, we hope to obtain a focused review in order to facilitate future approaches aimed at elucidating the immunological mechanisms that control gut inflammation.

Inflammatory bowel disease in an underdeveloped region of Northeastern Brazil

AIM: To evaluate the demographic characteristics and clinical phenotypes of inflammatory bowel disease (IBD) in a geographic area in Northeastern Brazil.

METHODS: This retrospective study was conducted at the Hospital of the Federal University of Piauí in Northeastern Brazil. Demographic characteristics and clinical phenotypes of IBD were analyzed in relation to the time of diagnostic confirmation, which was defined as the date of disease onset. Data were collected between January 2011 and December 2012 and included all census patients 18 years of age or older during that period for whom there was diagnostic confirmation of Crohn’s disease (CD), ulcerative colitis (UC), or unclassified colitis according to the Montreal criteria. We also analyzed the period of time between the onset of clinical manifestations and the diagnosis of IBD (delay in the diagnosis). Statistical analyses included means and standard deviations for numeric variables and the Pearson χ² adherence test for nominal variables. The annual index occurrence and overall prevalence of IBD at our institution were also calculated, with P values < 0.05 indicating statistical significance. This study was approved by the Institutional Ethics and Research Committee.

RESULTS: A total of 252 patients with IBD were included, including 152 (60.3%) UC patients and 100 (39.7%) CD patients. The clinical and demographic characteristics of all patients with IBD showed a female to male ratio of 1.3:1.0 and a mean age of 35.2 (SD = 14.5) years. In addition, the majority of patients were miscegenated (171, 67.9%), had received higher education (157, 62.4%), lived in urban areas (217, 86.1%), and were under the age of 40 years (97, 62.5%). For patients with CD, according to the Montreal classification, the predominant features present from the onset of disease were an age between 17 and 40 years (A2); colonic disease location (L2); and nonstricturing, nonfistulizing disease behavior (B1). However, approximately one-quarter of all CD patients demonstrated perineal involvement. We also observed considerable delay in the diagnosis of IBD throughout the entire study period (mean = 35.5 mo). In addition, the annual index occurrence rose from 0.08 to 1.53 cases/10⁵ inhabitants/year during the study period, and the prevalence rate was 12.8 cases/10⁵ inhabitants in 2012. Over the last two decades, there was a noted increase in the frequency of IBD in the study area.

CONCLUSION: In this study, there was a predominance of patients with UC, young people under 40 years of age, individuals with racial miscegenation, and low annual incomes.

Integrative Therapies and Pediatric Inflammatory Bowel Disease: The Current Evidence

Inflammatory bowel disease (IBD) primarily describes two distinct chronic conditions with unknown etiology, ulcerative colitis (UC) and Crohn’s disease (CD). UC is limited to the colon, while CD may involve any portion of the gastrointestinal tract from mouth to anus. These diseases exhibit a pattern of relapse and remission, and the disease processes are often painful and debilitating. Due to the chronic nature of IBD and the negative side effects of many of the conventional therapies, many patients and their families turn to complementary and alternative medicine (CAM) for symptom relief. This article focuses on the current available evidence behind CAM/integrative therapies for IBD.

Cell death and inflammatory bowel diseases: apoptosis, necrosis, and autophagy in the intestinal epithelium

Cell death mechanisms have been associated with the development of inflammatory bowel diseases in humans and mice. Recent studies suggested that a complex crosstalk between autophagy/apoptosis, microbe sensing, and enhanced endoplasmic reticulum stress in the epithelium could play a critical role in these diseases. In addition, necroptosis, a relatively novel programmed necrosis-like pathway associated with TNF receptor activation, seems to be also present in the pathogenesis of Crohn's disease and in specific animal models for intestinal inflammation. This review attempts to cover new data related to cell death mechanisms and inflammatory bowel diseases.

Genetic susceptibility and genotype-phenotype association in 588 Danish children with inflammatory bowel disease

AIM

To investigate the association between known inflammatory bowel disease (IBD)-associated genetic variants and development of paediatric IBD, and specific clinical sub-phenotypes.

MATERIAL AND METHODS

In this case-control study we included IBD patients <18 years of age at diagnosis from the Danish National Patient Registry and healthy children <18 years of age were randomly selected from the Danish Central Office of Civil Registration. The latter had filled out a questionnaire regarding health status, and DNA was obtained from blood samples and the buccal mucosa. Patient files were retrieved and clinical information was extracted. DNA was obtained from Guthrie cards from the Danish National Neonatal Screening Biobank (PKU-biobanken) at Statens Serum Institut and from blood samples.

RESULTS

A total of 588 IBD patients (244 Crohn's disease (CD), 318 ulcerative colitis (UC) and 26 IBD-unclassified (IBDU)) and 543 healthy controls were included. We found an association between CD and rs22411880 (ATG16L1, odds ratio (OR)=1.7 [1.1-1.7], p=0.003), rs5743289 (NOD2, OR=1.4 [1.1-1.9], p=0.009) and the paediatric specific rs1250550 (ZMIZ1, OR=0.7 [0.5-0.9], p=0.01). None of the investigated 41 SNPs were associated with disease localisation, medical treatment or surgery after correcting for multiple analyses.

CONCLUSION

We found an association between CD and three previously published genetic variants and replicated the association with the paediatric specific ZMIZ1 gene. No Bonferroni corrected significant genotype-phenotype associations were found. For future studies aimed at finding predictors for disease course in (paediatric) IBD, it will be worthwhile to include a combination of genetic, clinical and serological markers.

Phenotypic concordance in familial inflammatory bowel disease (IBD). Results of a nationwide IBD Spanish database

BACKGROUND & AIMS

Disease outcome has been found to be poorer in familial inflammatory bowel disease (IBD) than in sporadic forms, but assessment of phenotypic concordance in familial IBD provided controversial results. We assessed the concordance for disease type and phenotypic features in IBD families.

METHODS

Patients with familial IBD were identified from the IBD Spanish database ENEIDA. Families in whom at least two members were in the database were selected for concordance analysis (κ index). Concordance for type of IBD [Crohn's disease (CD) vs. ulcerative colitis (UC)], as well as for disease extent, localization and behaviour, perianal disease, extraintestinal manifestations, and indicators of severe disease (i.e., need for immunosuppressors, biological agents, and surgery) for those pairs concordant for IBD type, were analyzed.

RESULTS

798 out of 11,905 IBD patients (7%) in ENEIDA had familial history of IBD. Complete data of 107 families (231 patients and 144 consanguineous pairs) were available for concordance analyses. The youngest members of the pairs were diagnosed with IBD at a significantly younger age (p<0.001) than the oldest ones. Seventy-six percent of pairs matched up for the IBD type (κ=0.58; 95%CI: 0.42-0.73, moderate concordance). There was no relevant concordance for any of the phenotypic items assessed in both diseases.

CONCLUSIONS

Familial IBD is associated with diagnostic anticipation in younger individuals. Familial history does not allow predicting any phenotypic feature other than IBD type.

Significance of the genetic polymorphism of CYP2D6 and NAT2 in patients with inflammatory bowel diseases

BACKGROUND

The main types of inflammatory bowel diseases (IBD) are ulcerative colitis (UC) and Crohn's disease (CD). There is evidence that, in addition to immunological and environmental factors, genetic factors also play an important role in the pathogenesis of IBD. Determination of polymorphism of CYP2D6 and NAT2 genes encoding I and II phase enzymes of xenobiotic biotransformation may have clinical value as an indicator of individual predisposition to diseases, and also contribute to effective and safe pharmacotherapy. The aim of this study was to investigate the association between genetic polymorphism of CYP2D6 and NAT2 and the incidence of IBD, including UC and CD, among inhabitants of central Poland.

METHODS

The study was performed in 258 individuals from central Poland (115 patients with IBD, including 65 patients with UC and 50 with CD; and in 143 healthy controls). The CYP2D6 genotypes of oxidation and NAT2 genotypes of acetylation were analyzed using the PCR-RFLP method.

RESULTS

There were no statistically significant differences in the frequency of the CYP2D6 genotypes and alleles in patients with IBD, UC and CD in comparison with the control group. The relative risk (OR) of IBD, UC and CD was higher in carriers of the allele NAT2*7 and was OR=3.49 (p=0.0019), OR=3.86 (p=0.0019), and OR=3.02 (p=0.0247), respectively.

CONCLUSIONS

Polymorphism of the gene encoding CYP2D6 does not affect the incidence of inflammatory bowel diseases. The carriers of the NAT2*7 allele which determines slow acetylation may be more predisposed to inflammatory bowel diseases, including ulcerative colitis and Crohn's disease.

Interleukin-33 and inflammatory bowel diseases: lessons from human studies

Interleukin- (IL-) 33 is a widely expressed cytokine present in different cell types, such as epithelial, mesenchymal, and inflammatory cells, supporting a predominant role in innate immunity. IL-33 can function as a proinflammatory cytokine inducing Th2 type of immune response being involved with the defense against parasitic infections of the gastrointestinal tract. In addition, it has been proposed that IL-33 can act as a signaling molecule alerting the immune system of danger or tissue damage. Recently, in the intestinal mucosa, overexpression of IL-33 has been reported in samples from patients with inflammatory bowel diseases (IBD). This review highlights the available data regarding IL-33 in human IBD and discusses emerging roles for IL-33 as a key modulator of intestinal inflammation.

Low hygiene and exposure to infections may be associated with increased risk for ulcerative colitis in a North Indian population

BACKGROUND

Previous studies have attempted to link hygiene hypothesis with IBD. However most of these studies come from developed countries where the level of hygiene is high and universal. Very little data is available from developing countries. The present study explores the truth of hygiene hypotheses and other risk factors for ulcerative colitis (UC) in a North Indian population where the prevalence of UC has been increasing.

METHODS

A total of 518 patients diagnosed with UC and 188 age-matched controls were included in the study. A structured questionnaire concerning socio-demographics and level of hygiene was completed by all participants. Logistic regression analysis was used to study the association between hygiene-related factors and the risk for UC. Odds ratios and 95% confidence intervals were estimated.

RESULTS

There was a higher proportion of females (P<0.001), and a higher educational status (P=0.01) in UC patients compared with controls. A family history of IBD was present in 7.2% of cases and non-existent in controls. On multivariate analysis, after accounting for potential confounders, having a private bed (P<0.001), and having better toilet facilities [(RCA versus none, P=0.01; Flush toilet versus none, P=0.01), (RCA LATRINE as a toilet technology used in rural areas where no flush facility exists. It was developed under RCA project)] were inversely associated with risk for UC whereas owning a pet (P=0.01) and stressful events like a death in the family (P=0.01) were associated with greater risks for UC.

CONCLUSION

Our study does not provide definitive evidence to support hygiene hypothesis and rather suggests that the rising incidence of UC in North India may be attributable to inadequate sanitary measures or other as yet unidentified factors.

Inflammatory bowel disease: mechanisms, redox considerations, and therapeutic targets

Oxidative stress is thought to play a key role in the development of intestinal damage in inflammatory bowel disease (IBD), because of its primary involvement in intestinal cells' aberrant immune and inflammatory responses to dietary antigens and to the commensal bacteria. During the active disease phase, activated leukocytes generate not only a wide spectrum of pro-inflammatory cytokines, but also excess oxidative reactions, which markedly alter the redox equilibrium within the gut mucosa, and maintain inflammation by inducing redox-sensitive signaling pathways and transcription factors. Moreover, several inflammatory molecules generate further oxidation products, leading to a self-sustaining and auto-amplifying vicious circle, which eventually impairs the gut barrier. The current treatment of IBD consists of long-term conventional anti-inflammatory therapy and often leads to drug refractoriness or intolerance, limiting patients' quality of life. Immune modulators or anti-tumor necrosis factor α antibodies have recently been used, but all carry the risk of significant side effects and a poor treatment response. Recent developments in molecular medicine point to the possibility of treating the oxidative stress associated with IBD, by designing a proper supplementation of specific lipids to induce local production of anti-inflammatory derivatives, as well as by developing biological therapies that target selective molecules (i.e., nuclear factor-κB, NADPH oxidase, prohibitins, or inflammasomes) involved in redox signaling. The clinical significance of oxidative stress in IBD is now becoming clear, and may soon lead to important new therapeutic options to lessen intestinal damage in this disease.

New insights on the pathomechanisms of inflammatory bowel disease

Pathogenesis of inflammatory bowel disease (IBD) remains an enigma on whether germs, genes or a combination of these two with excessive immune responses to gut-associated bacteria explicates its pathomechanisms. The incidence of IBD is 0.76747 per 100,000 in Central Indonesia, as shown in the Project Indonesian IBD ACCESS 2012 progress report. This result, together with other epidemiological studies in Asia, may conclusively reflect increased rates of the disease, while its pathogenesis still undoubtedly obscured. However, knowledge of the pathophysiology of IBD is rapidly growing, abreast with new developments. A series of recent updates in core pathomechanisms such as bacterial, endoplasmic reticulum stress, new immune cell populations, T-cell differentiation and function, mucosal immune defenses and oxidative stress are relevant pathomechanism keypoints in IBD.

Evaluation of the usefulness of colonoscopy with mucosal biopsies in the follow-up of TNBS-induced colitis in rats

Animal models are required for research regarding the pathogenesis and efficacy of anti-inflammatory agents in inflammatory bowel disease (IBD). Trinitrobenzene sulfonic acid (TNBS)-induced colitis closely mimics Crohn's disease. The present study was undertaken in order to determine the reliability of following the inflammatory course of TNBS-induced colitis using colonoscopy together with biopsy samples obtained during the examination. In this study we used 20 adult male Wistar rats, with a mean weight of 201.9 g. The rats were divided into two groups, control and TNBS, with ten rats in each group. Following the induction of TNBS colitis, the rats underwent colonoscopy with mucosal biopsies. At the end of the experiment, the rats were sacrificed and whole-wall colonic samples were obtained. The degree of inflammation was assessed endoscopically, macroscopically and microscopically. There was no significant change in the body weight of the control group but significant weight loss was observed in the TNBS group. Examination of the control group did not reveal any inflammation. Severe colitis was observed in the TNBS-induced colitis rats, as assessed endoscopically, macroscopically and microscopically. The endoscopic inflammation score obtained through colonoscopy examinations correlated with that obtained macroscopically, and those obtained microscopically from the whole-wall colon and biopsy samples collected during the colonoscopy. Moreover, the inflammation scores obtained from the whole-wall colon and biopsy samples collected during colonoscopy correlated markedly. In conclusion, colonoscopy is a reliable method for following up the course of inflammation in experimentally induced colitis. Although biopsy samples collected during colonoscopies may be used to assess the degree of inflammation, whole-wall samples are superior in this regard.

High smoking cessation rate in Crohn's disease patients after physician advice--the TABACROHN Study

INTRODUCTION

Tobacco smoking has a significant impact on the development of Crohn's disease (CD) and its clinical course, making smoking cessation one of the main goals in CD therapeutic strategy.

AIMS

To evaluate the effectiveness of an advice-based smoking cessation strategy among CD patients.

METHODS

We have performed a prospective multicenter study which enrolled 408 CD smokers. At inclusion all patients were instructed about the risks of smoking and subsequently followed every 3 months. Each center used additional smoking cessation strategies based on available resources. Urinary cotinine and exhaled carbon monoxide levels were evaluated in a subgroup of patients.

RESULTS

Median study follow up was 18 months. 31% of the patients achieved complete smoking cessation and 23% were smoking-free at the end of their follow up with 8% of smoking relapse. Most patients not achieving smoking cessation did not change their smoking habit with only 5% presenting a decrease in tobacco load. 63% of patients willing to quit smoking received help from another specialist, most frequently the pulmonologist (47%). Surprisingly, most patients (88%) tried to quit smoking with no pharmacological therapy and bupropion, varenicline and nicotine replacement treatment were used in few patients. Urinary cotinine and exhaled CO levels tested in a subgroup of patients proved to have a good correlation with the self-reported smoking habit. No predictors of successful smoking cessation were identified.

CONCLUSION

Our results underline that an anti-tobacco strategy mostly based on CD patients's education and counseling is feasible and effective in helping patients reach complete abstinence.

[Data for the decrease of "voluntary childlessness" in inflammatory bowel disease]

Inflammatory bowel disease is a chronic disorder affecting young adults in their reproductive years, hence its populational consequences are not negligible. While fertility in inflammatory bowel disease is the same as in the general population (except for male patients with sulphasalazine treatment and females with ileum-pouch anal anastomosis), "voluntary childlessness" is higher, 14-18%. Patients require accurate counseling addressing fertility, pregnancy course and outcome. They need to be informed appropriately about risks and benefits of medications in inflammatory bowel disease in order to assist their decision making, decrease "voluntary childlessness" and improve compliance. Authors review the issues related to fertility, outcome of pregnancy, medical treatment options before and during pregnancy as well as during breastfeeding in inflammatory bowel disease.

Association of fucosyltransferase 2 gene variants with ulcerative colitis in Han and Uyghur patients in China

AIM

To investigate the contribution of fucosyltransferase 2 (FUT2) variants to the genetic susceptibility and clinical heterogeneity of ulcerative colitis (UC) between Han and Uyghur patients in Xinjiang, China.

METHODS

A total of 102 UC patients (53 Han patients including 22 men and 31 women, and 49 Uyghur patients including 25 men and 24 women; aged 48 ± 16 years) and 310 age- and sex-matched healthy controls were enrolled from January 2010 to May 2011 in Xinjiang People's Hospital of China. UC was diagnosed based on the clinical, endoscopic and histological findings following Lennard-Jones criteria. Blood samples were collected and genomic DNA was extracted by the routine laboratory methods. Polymerase chain reaction-sequence-based typing method was used to identify FUT2 variants rs281377, rs1047781, rs601338 and rs602662. Genotypic and allelic frequencies were documented and compared between the UC patients and the healthy controls. Genotypic frequencies were also compared between Han and Uyghur patients. Potential association of genetic variation and UC between Han and Uyghur patients was examined.

RESULTS

rs281377 was found significantly associated with UC in the Han population as compared with the controls (P = 0.011) while rs281377 was not associated with UC in the Uyghur population (P = 0.06). TT homozygous rs281377 frequencies were higher in the UC groups than in the controls (88.7% vs 68.7% and 55.1% vs 50.3%). rs1047781 was specifically associated with UC in the Uyghur population (P = 0.001), but not associated with UC in the Han population (P = 0.13). TT homozygous rs1047781 frequencies were lower in the UC groups than in the controls (9.5% vs 11.8% and 4.0% vs 6.7%). rs601338 was statistically related to UC in both populations (Han, P = 0.025; Uyghur, P = 8.33 × 10(-5)). AA homozygous rs601338 frequencies were lower in the UC groups than in the controls (0% vs 1.8% and 12.2% vs 13.4%). No association was found between rs602662 and UC in both Han and the Uyghur populations. Allelic analysis showed that rs281377 allele was significantly associated with UC in the Han population as compared with the controls [P = 0.001, odd ratio (OR) = 0.26], however, it was not associated with UC in the Uyghur population (P = 0.603, OR = 1.14), and rs1047781 allele was associated with UC in the Uyghur population (P = 0.001, OR = 0.029) while it was not associated with UC in the Han population (P = 0.074, OR = 0.62). Moreover, rs601338 was associated with UC in both Han (P = 0.005, OR = 0.1) and Uyghur populations (P = 0.002, OR = 0.43). Meta analysis showed that rs1047781 and rs601338 conferred risk of UC as compared with the controls [P = 0.005, OR = 0.47; P = 0.0003, OR = 0.35; 95% confidence interval (CI) = 0.31-0.72 and 0.21-0.58], but rs281377 and rs602662 showed no statistically significant differences between patients with UC and controls (P = 0.10, OR = 0.71; P = 0.68, OR = 0.09; 95% CI = 0.47-1.07 and 0.56-1.47).

CONCLUSION

Functionally relevant FUT2 gene variants are associated with UC, suggesting that they play a potential role in the pathogenesis of UC and may contribute to the clinical heterogeneity of UC between Han and Uyghur patients.

Etiology of inflammatory bowel disease: a unified hypothesis

Inflammatory bowel disease (IBD), including both ulcerative colitis (UC) and Crohn's disease (CD), emerged and dramatically increased for about a century. Despite extensive research, its cause remains regarded as unknown. About a decade ago, a series of findings made me suspect that saccharin may be a key causative factor for IBD, through its inhibition on gut bacteria and the resultant impaired inactivation of digestive proteases and over digestion of the mucus layer and gut barrier (the Bacteria-Protease-Mucus-Barrier hypothesis). It explained many puzzles in IBD such as its emergence and temporal changes in last century. Recently I further found evidence suggesting sucralose may be also linked to IBD through a similar mechanism as saccharin and have contributed to the recent worldwide increase of IBD. This new hypothesis suggests that UC and CD are just two symptoms of the same morbidity, rather than two different diseases. They are both caused by a weakening in gut barrier and only differ in that UC is mainly due to increased infiltration of gut bacteria and the resultant recruitment of neutrophils and formation of crypt abscess, while CD is mainly due to increased infiltration of antigens and particles from gut lumen and the resultant recruitment of macrophages and formation of granulomas. It explained the delayed appearance but accelerated increase of CD over UC and many other phenomena. This paper aims to provide a detailed description of a unified hypothesis regarding the etiology of IBD, including the cause and mechanism of IBD, as well as the relationship between UC and CD.