Extraintestinal manifestations and complications in inflammatory bowel disease: from shared genetics to shared biological pathways

Serum urate is associated with an increased risk of inflammatory bowel disease: A bidirectional Mendelian randomization study

BACKGROUND

Previous studies have indicated bidirectional associations between urate levels and inflammatory bowel disease (IBD), including ulcerative colitis (UC) and Crohn's disease (CD). However, it remains unclear whether the observations are causal because of confounding factors.

AIM

To investigate the causal associations between urate levels and IBD using bidirectional Mendelian randomization (MR).

METHODS

Independent genetic variants for urate levels and IBD were selected as instrumental variables from published genome-wide association studies (GWASs). Summary statistics for instrument-outcome associations were retrieved from three separate databases for IBD (the UK Biobank, the FinnGen database and a large GWAS meta-analysis) and one for urate levels (a large GWAS meta-analysis). MR analyses included the inverse-variance-weighted method, weighted-median estimator, MR-Egger and sensitivity analyses (MR-PRESSO). A meta-analysis was also conducted to merge the data from separate outcome databases using a fixed-effects model.

RESULTS

Genetically higher serum urate levels were strongly associated with an increased risk of UC [odds ratio (OR): 1.95, 95% confidence interval (CI): 1.86-2.05] after outlier correction, and the ORs (95%CIs) for IBD and CD were 0.94 (95%CI: 0.86-1.03) and 0.91 (95%CI: 0.80-1.04), respectively. Animal studies have confirmed the positive association between urate levels and UC. Moreover, genetically predicted IBD was inversely related to urate levels (OR: 0.97, 95%CI: 0.94-0.99). However, no association was observed between genetically influenced UC or CD and urate levels.

CONCLUSION

Urate levels might be risk factors for UC, whereas genetically predicted IBD was inversely associated with urate levels. These findings provide essential new insight for treating and preventing IBD.

Renal manifestations in inflammatory bowel disease: a systematic review

As extra-intestinal manifestations (EIMs) are frequent in inflammatory bowel disease (IBD) and affect morbidity and sometimes even mortality, vigilance in the surveillance of EIMs and installing the appropriate treatment are essential. Data on renal manifestations in patients with IBD are however rare. Nevertheless, up to 5-15% of adult patients with IBD will develop chronic kidney disease over time. The pathophysiology of renal involvement in patients with IBD is complex and poorly understood, with a wide range of renal disorders affecting the glomeruli and/or the tubular structure. Furthermore, medication used to treat IBD can be potentially nephrotoxic and metabolic complication due to the disease itself can furthermore cause renal damage. The aim of this systematic review is to provide an overview of the existing data in literature on these renal manifestations and complications in patients with IBD.

[Systemic manifestations of inflammatory bowel diseases]

The article is devoted to the current data regarding the pathogenesis, classification and frequency of extraintestinal manifestations (EIMs) in inflammatory bowel diseases. We discuss two distinct theories of EIMs pathogenesis. First, EIMs arise from an extension of antigen-specific immune responses from the intestine to non-intestinal sites. Second, EIMs are independent inflammatory events initiated or perpetuated by the presence of IBD or by shared genetic or environmental risk factors in the host. These mechanisms are not mutually exclusive and may contribute to varying degrees in different EIMs. Early diagnosis of EIMs contributes to prevention disability and enhancement of quality of life of IBD patients. It is concluded that treatment of extraintestinal manifestations should be carried out taking into account the course of the IBD and the multidisciplinary approach, which requires close cooperation of doctors of various specialties. Assessment of prognostic markers and predictors for EIM in IBD will be part of a future investigation.

ATG16L1 T300A polymorphism is associated with Crohn's disease in a Northwest Greek cohort, but ECM1 T130M and G290S polymorphisms are not associated with ulcerative colitis

Background:

Crohn’s disease (CD) and ulcerative colitis (UC) are well-described disease entities with unknown etiopathogenesis. Environmental, genetic, gut microbiota, and host immune response correlations have been implicated. The role of susceptibility gene polymorphisms, such as ATG16L1 T300A and ECM1 T130M and G290S, is well-described, although controversial findings have been reported.

Methods:

Two hundred five patients with inflammatory bowel disease (108 CD and 97 UC), and 223 healthy blood donors (control group) from the Northwest Greece region were genotyped for rs2241880 (T300A), rs3737240 (T130M) and rs13294 (G290S) single nucleotide polymorphisms. Genotyping was performed using the real-time polymerase chain reaction method.

Results:

The frequency of G allele was significantly higher in CD patients compared to the control group (P=0.029; odds ratio [OR] 1.45, 95% confidence interval [CI] 1.04-2.03). Carriers of two G alleles (T300A), compared to those carrying only one, were 1.3 times more susceptible to CD (P=0.022; OR 2.45, 95%CI 1.14-5.27). In CD patients, the presence of the T300A polymorphism indicates a possible protective effect against developing a penetrating (B3) phenotype, while in UC patients, presence of the T300A polymorphism, indicates a possible protective effect against developing joint-involving extraintestinal manifestations.

Conclusion:

Our study found a significant association of the T300A polymorphism with CD susceptibility, suggesting that CD occurrence in our population has a strong genetic background, with the T300A G allele having an additive effect.

Extraintestinal Manifestations of Inflammatory Bowel Disease: Epidemiology, Etiopathogenesis, and Management

PURPOSE OF REVIEW

Extraintestinal manifestations (EIMs) of inflammatory bowel disease (IBD) represent a complex array of disease processes with variable epidemiologic penetrance, genetic antecedents, and phenotypic presentations. The purpose of this review is to provide an overview of primary and secondary EIMs as well as salient treatment strategies utilized.

RECENT FINDINGS

While the genetic antecedents remain incompletely understood, the treatment armamentarium for EIMs has expanded with new pharmaceutical drug classes that effectively treat IBD. EIMs are an increasingly recognized complication of IBD that require prompt recognition, multidisciplinary management, and a multifaceted therapeutic approach. This review highlights the complexities and ramifications of EIM management and offers therapeutic guidance.

Adalimumab Reduces Extraintestinal Manifestations in Patients with Crohn's Disease: A Pooled Analysis of 11 Clinical Studies

Introduction

Extraintestinal manifestations (EIMs) in patients with Crohn’s disease (CD) are common and associated with additional morbidity. This study aimed to evaluate the effect of adalimumab therapy on EIM resolution and identify potential predictors of EIM resolution in adult and pediatric patients with moderate to severe CD.

Methods

EIM data were pooled from 11 induction, maintenance, and open-label extension studies of adalimumab. Resolution of EIMs was evaluated at approximately 6 months and 1 year. Median time to initial EIM resolution and first EIM recurrence (reflecting durable resolution) of any EIM and specific categories of EIMs (arthritis/arthralgia, ocular, cutaneous) were calculated. A Cox model was used to determine predictors of initial and durable EIM resolution.

Results

At baseline, 54% (1137/2094) of patients receiving adalimumab and 51% (297/586) receiving placebo had EIMs. EIM resolution occurred in a significantly greater proportion of adalimumab versus placebo patients at 6 months (54% vs 31%; P < .001) and 1 year (60% vs 42%; P = .008). Median time to initial resolution of any EIM, arthritis/arthralgia, and cutaneous EIMs was significantly shorter in patients receiving adalimumab versus placebo. Durable resolution of any EIM and arthritis/arthralgia was significantly longer for patients receiving adalimumab versus placebo. Clinically meaningful predictors of EIM resolution included adalimumab treatment, male sex, and moderate (versus severe) disease activity at baseline.

Conclusion

Adalimumab is effective for achieving initial and durable resolution of any EIM and, in particular, arthritis/arthralgia in patients with moderate to severe CD. Predictors of EIM resolution included adalimumab treatment and moderate disease severity.

Funding

AbbVie.

Electronic supplementary material

The online version of this article (10.1007/s12325-018-0678-0) contains supplementary material, which is available to authorized users.

Age and fecal microbial strain-specific differences in patients with spondyloarthritis

Background

Prior studies have demonstrated abnormalities in the composition of the gastrointestinal microbiota in pediatric and adult patients with spondyloarthritis (SpA). In particular, diminished fecal abundance of Faecalibacterium prausnitzii and abnormalities in both directions in the abundance of the Bacteroides genus have been identified.

Methods

We obtained fecal specimens from 30 children with treatment-naïve enthesitis-related arthritis (ERA) and 19 healthy controls, as well as specimens from 11 adult patients with longstanding SpA and 10 adult healthy controls. All of the samples underwent sequencing of the 16S ribosomal DNA. A subset of the pediatric fecal samples was subjected to shotgun metagenomics sequencing.

Results

ERA patients had decreased abundance of the anti-inflammatory F. prausnitzii A2-165 strain (41 ± 28% versus 54 ± 20% of all sequences matching F. prausnitzii, p = 0.084) and an increased abundance of the control F. prausnitzii L2/6 strain (28 ± 28% versus 15 ± 15%, p = 0.038). Similar trends were observed in adults with longstanding SpA (n = 11) and controls (n = 10). In contrast, the fecal abundance of Bacteroides fragilis was increased in ERA subjects (2.0 ± 4.0% versus 0.45 ± 0.7% of all sequences, p = 0.045), yet was diminished in adult subjects (0.2 ± % versus 1.0 ± % of all sequences, p = 0.106). Shotgun metagenomics sequencing of the fecal DNA in the pediatric subjects revealed diminished coverage of the butanoate pathway (abundance normalized to controls of 1 ± 0.48 versus 0.72 ± 0.33 in ERA, p = 0.037).

Conclusions

The anti-inflammatory F. prausnitzii A2-165 strain appears to be depleted in both pediatric and adult SpA. In contrast, B. fragilis may be depleted in adult disease yet abundant in pediatric SpA, suggesting developmental effects on the immune system.

Electronic supplementary material

The online version of this article (10.1186/s13075-018-1510-6) contains supplementary material, which is available to authorized users.

Urolithiasis in inflammatory bowel disease and bariatric surgery

AIM

To analyse current literature focusing on pathogenesis and therapeutic aspects of urolithiasis with inflammatory bowel disease (IBD) and following bariatric surgery.

METHODS

A systematic literature search was performed using PubMed, supplemented with additional references. Studies assessing the association of IBD or bariatric surgery with renal stones in both paediatric and adulthood were included.

RESULTS

Certain types of stones are seen more frequently with IBD. Hyperoxaluria and hypocitraturia are the main metabolic changes responsible for urolithiasis. The incidence of renal stones in malabsorptive types of bariatric surgery such as gastric bypass is high; this is not as common in modern restrictive surgical methods. Preventative methods and urine alkalinisation have been shown to be beneficial.

CONCLUSION

Both conditions are associated with renal stones. Patients’ counselling and prevention strategies are the mainstay of urolithiasis management in these patients.

Validity, Reliability, and Responsiveness of the Brief Pain Inventory in Inflammatory Bowel Disease

Background and Aims. No patient-reported outcome measures targeting pain have yet been validated for use in IBD patients. Consequently, the aim of this study was to test the psychometrical properties of the brief pain inventory (BPI) in an outpatient population with IBD. Methods. Participants were recruited from nine hospitals in the southeastern and western parts of Norway. Clinical and sociodemographic data were collected, and participants completed the BPI, as well as the Short-Form 36 (SF-36). Results. In total, 410 patients were included. The BPI displayed high correlations with the bodily pain dimension of the SF-36, as well as moderate correlations with disease activity indices. The BPI also displayed excellent internal consistency (Cronbach's alpha value of 0.91, regardless of diagnosis) and good to excellent test-retest values (intraclass correlation coefficient (ICC) 0.84-0.90 and Kappa values > .70). In UC, calculation of responsiveness revealed that only BPI interference in patients reporting improvement reached the threshold of 0.2. In CD, Cohen's d ranged from 0.26 to 0.68. Conclusions. The BPI may serve as an important supplement in patient-reported outcome measurement in IBD. There is need to confirm responsiveness in future studies. Moreover, responsiveness should ideally be investigated using changes in objective markers of inflammation.

Advances in nutritional therapy in inflammatory bowel diseases: Review

Inflammatory bowel diseases (IBD), including ulcerative colitis and Crohn's disease are chronic, life-long, and relapsing diseases of the gastrointestinal tract. Currently, there are no complete cure possibilities, but combined pharmacological and nutritional therapy may induce remission of the disease. Malnutrition and specific nutritional deficiencies are frequent among IBD patients, so the majority of them need nutritional treatment, which not only improves the state of nutrition of the patients but has strong anti-inflammatory activity as well. Moreover, some nutrients, from early stages of life are suspected as triggering factors in the etiopathogenesis of IBD. Both parenteral and enteral nutrition is used in IBD therapy, but their practical utility in different populations and in different countries is not clearly established, and there are sometimes conflicting theories concerning the role of nutrition in IBD. This review presents the actual data from research studies on the influence of nutrition on the etiopathogenesis of IBD and the latest findings regarding its mechanisms of action. The use of both parenteral and enteral nutrition as therapeutic methods in induction and maintenance therapy in IBD treatment is also extensively discussed. Comparison of the latest research data, scientific theories concerning the role of nutrition in IBD, and different opinions about them are also presented and discussed. Additionally, some potential future perspectives for nutritional therapy are highlighted.

Extraintestinal manifestations of inflammatory bowel disease

Inflammatory bowel disease (IBD) is a systemic disease, and it not only affects the gastrointestinal tract, but also may show a variety of extraintestinal manifestations (EIMs). EIMs can involve multiple systems. This paper reviews the EIMs of IBD for a more comprehensive understanding of IBD to guide its clinical diagnosis and treatment.

The genomic landscape of human immune-mediated diseases

As the methodology of genetic detection has developed rapidly in recent years, through techniques such as genome-wide association studies (GWAS) and the secondary generation of sequencing, we are able to view the genomic landscape more clearly. It is well known that genes have a vital role in the pathogenesis of immune-mediated diseases (IMDs), which could provide important insight into new clinical therapeutic targets. Here, we review the genomic landscape of IMDs and analyse overlapping loci between diseases. There may be a need for more epigenetics studies to aid in the understanding of the transition from genotype to phenotype.