Inflammatory Bowel Disease and Cardiovascular Diseases

BACKGROUND

Emerging data showed patients with chronic inflammatory disorders, including inflammatory bowel disease, are more likely to develop atherosclerotic cardiovascular diseases, heart failure, and atrial fibrillation. This article aims to review the evidence of those associations.

METHODS

PubMed was searched from inception to January 2022 using the keywords, including inflammatory bowel diseases, Crohn disease, ulcerative colitis, atherosclerotic cardiovascular disease, coronary artery disease, cardiovascular disease, atrial fibrillation, heart failure, and premature coronary artery disease. Relevant literature, including retrospective/prospective cohort studies, clinical trials, meta-analyses, and guidelines, were reviewed and summarized.

RESULTS

Both ulcerative colitis and Crohn disease are associated with an increased risk of atherosclerotic cardiovascular diseases, cerebrovascular accidents, premature coronary artery disease, and atrial fibrillation. Ulcerative colitis is associated with an increased risk of heart failure. The increased atrial fibrillation occurred during inflammatory bowel disease flares and persistent activity but not during periods of remission. Hypotheses for the mechanism underlying the association of inflammatory bowel disease and atherosclerotic cardiovascular diseases include shared risk factors (ie, obesity, diabetes, smoking, diet) and pathophysiology (gut microbiome dysfunction) or adverse effects from inflammatory bowel disease itself or its treatment (ie, chronic inflammation, dyslipidemia, thrombocytosis, steroids).

CONCLUSION

Inflammatory bowel disease is associated with an increased risk of atherosclerotic cardiovascular diseases, heart failure, and atrial fibrillation. A multidisciplinary team with gastroenterologists and cardiologists is needed to optimize the care for patients with inflammatory bowel disease and associated cardiac diseases.

Single-Cell Analysis Reveals Unexpected Cellular Changes and Transposon Expression Signatures in the Colonic Epithelium of Treatment-Naïve Adult Crohn's Disease Patients

BACKGROUND & AIMS

The intestinal barrier comprises a monolayer of specialized intestinal epithelial cells (IECs) that are critical in maintaining mucosal homeostasis. Dysfunction within various IEC fractions can alter intestinal permeability in a genetically susceptible host, resulting in a chronic and debilitating condition known as Crohn's disease (CD). Defining the molecular changes in each IEC type in CD will contribute to an improved understanding of the pathogenic processes and the identification of cell type-specific therapeutic targets. We performed, at single-cell resolution, a direct comparison of the colonic epithelial cellular and molecular landscape between treatment-naïve adult CD and non-inflammatory bowel disease control patients.

METHODS

Colonic epithelial-enriched, single-cell sequencing from treatment-naïve adult CD and non-inflammatory bowel disease patients was investigated to identify disease-induced differences in IEC types.

RESULTS

Our analysis showed that in CD patients there is a significant skew in the colonic epithelial cellular distribution away from canonical LGR5+ stem cells, located at the crypt bottom, and toward one specific subtype of mature colonocytes, located at the crypt top. Further analysis showed unique changes to gene expression programs in every major cell type, including a previously undescribed suppression in CD of most enteroendocrine driver genes as well as L-cell markers including GCG. We also dissect an incompletely understood SPIB+ cell cluster, revealing at least 4 subclusters that likely represent different stages of a maturational trajectory. One of these SPIB+ subclusters expresses crypt-top colonocyte markers and is up-regulated significantly in CD, whereas another subcluster strongly expresses and stains positive for lysozyme (albeit no other canonical Paneth cell marker), which surprisingly is greatly reduced in expression in CD. In addition, we also discovered transposable element markers of colonic epithelial cell types as well as transposable element families that are altered significantly in CD in a cell type-specific manner. Finally, through integration with data from genome-wide association studies, we show that genes implicated in CD risk show heretofore unknown cell type-specific patterns of aberrant expression in CD, providing unprecedented insight into the potential biological functions of these genes.

CONCLUSIONS

Single-cell analysis shows a number of unexpected cellular and molecular features, including transposable element expression signatures, in the colonic epithelium of treatment-naïve adult CD.

Increased colonic expression of ACE2 associates with poor prognosis in Crohn's disease

The host receptor for SARS-CoV-2, angiotensin-converting enzyme 2 (ACE2), is highly expressed in small intestine. Our aim was to study colonic ACE2 expression in Crohn's disease (CD) and non-inflammatory bowel disease (non-IBD) controls. We hypothesized that the colonic expression levels of ACE2 impacts CD course. We examined the expression of colonic ACE2 in 67 adult CD and 14 NIBD control patients using RNA-seq and quantitative (q) RT-PCR. We validated ACE2 protein expression and localization in formalin-fixed, paraffin-embedded matched colon and ileal tissues using immunohistochemistry. The impact of increased ACE2 expression in CD for the risk of surgery was evaluated by a multivariate regression analysis and a Kaplan–Meier estimator. To provide critical support for the generality of our findings, we analyzed previously published RNA-seq data from two large independent cohorts of CD patients. Colonic ACE2 expression was significantly higher in a subset of adult CD patients which was defined as the ACE2-high CD subset. IHC in a sampling of ACE2-high CD patients confirmed high ACE2 protein expression in the colon and ileum compared to ACE2-low CD and NIBD patients. Notably, we found that ACE2-high CD patients are significantly more likely to undergo surgery within 5 years of CD diagnosis, and a Cox regression analysis found that high ACE2 levels is an independent risk factor for surgery (OR 2.17; 95% CI, 1.10–4.26; p = 0.025). Increased intestinal expression of ACE2 is associated with deteriorated clinical outcomes in CD patients. These data point to the need for molecular stratification that can impact CD disease-related outcomes.

Whole-genome sequencing of African Americans implicates differential genetic architecture in inflammatory bowel disease

Whether or not populations diverge with respect to the genetic contribution to risk of specific complex diseases is relevant to understanding the evolution of susceptibility and origins of health disparities. Here, we describe a large-scale whole-genome sequencing study of inflammatory bowel disease encompassing 1,774 affected individuals and 1,644 healthy control Americans with African ancestry (African Americans). Although no new loci for inflammatory bowel disease are discovered at genome-wide significance levels, we identify numerous instances of differential effect sizes in combination with divergent allele frequencies. For example, the major effect at PTGER4 fine maps to a single credible interval of 22 SNPs corresponding to one of four independent associations at the locus in European ancestry individuals but with an elevated odds ratio for Crohn disease in African Americans. A rare variant aggregate analysis implicates Ca²⁺-binding neuro-immunomodulator CALB2 in ulcerative colitis. Highly significant overall overlap of common variant risk for inflammatory bowel disease susceptibility between individuals with African and European ancestries was observed, with 41 of 241 previously known lead variants replicated and overall correlations in effect sizes of 0.68 for combined inflammatory bowel disease. Nevertheless, subtle differences influence the performance of polygenic risk scores, and we show that ancestry-appropriate weights significantly improve polygenic prediction in the highest percentiles of risk. The median amount of variance explained per locus remains the same in African and European cohorts, providing evidence for compensation of effect sizes as allele frequencies diverge, as expected under a highly polygenic model of disease.

Increased Colonic Expression of ACE2 Associates with Poor Prognosis in Crohn's disease

Background and Aims

The host receptor for SARS-CoV-2, angiotensin-converting enzyme 2 (ACE2), is highly expressed in small intestine. Our aim was to study colonic ACE2 expression in Crohn's disease (CD) and non-inflammatory bowel disease (non-IBD) controls. We hypothesized that the colonic expression levels of ACE2 impacts CD course.

Methods

We examined the expression of colon ACE2 using RNA-seq and quantitative (q) RT-PCR from 69 adult CD and 14 NIBD control patients. In a subset of this cohort we validated ACE2 protein expression and localization in formalin-fixed, paraffin-embedded matched colon and ileal tissues using immunohistochemistry. The impact of increased ACE2 expression in CD for the risk of surgery was evaluated by a multivariate regression analysis and a Kaplan-Meier estimator. To provide critical support for the generality of our findings, we analyzed previously published RNA-seq data from two large independent cohorts of CD patients.

Results

Colonic ACE2 expression was significantly higher in a subset of adult CD patients (ACE2-high CD). IHC in a sampling of ACE2-high CD patients confirmed high ACE2 protein expression in the colon and ileum compared to ACE2-low CD and NIBD patients. Notably, we found that ACE2-high CD patients are significantly more likely to undergo surgery within 5 years of diagnosis, with a Cox regression analysis finding that high ACE2 levels is an independent risk factor (OR 2.18; 95%CI, 1.05-4.55; p=0.037).

Conclusion

Increased intestinal expression of ACE2 is associated with deteriorated clinical outcomes in CD patients. These data point to the need for molecular stratification that may impact CD disease-related outcomes.

Decreased Colonic Activin Receptor-Like Kinase 1 Disrupts Epithelial Barrier Integrity in Patients With Crohn's Disease

BACKGROUND & AIMS

Intestinal epithelial cell (IEC) barrier dysfunction is critical to the development of Crohn's disease (CD). However, the mechanism is understudied. We recently reported increased microRNA-31-5p (miR-31-5p) expression in colonic IECs of CD patients, but downstream targets and functional consequences are unknown.

METHODS

microRNA-31-5p target genes were identified by integrative analysis of RNA- and small RNA-sequencing data from colonic mucosa and confirmed by quantitative polymerase chain reaction in colonic IECs. Functional characterization of activin receptor-like kinase 1 (ACVRL1 or ALK1) in IECs was performed ex vivo using 2-dimensional cultured human primary colonic IECs. The impact of altered colonic ALK1 signaling in CD for the risk of surgery and endoscopic relapse was evaluated by a multivariate regression analysis and a Kaplan-Meier estimator.

RESULTS

ALK1 was identified as a target of miR-31-5p in colonic IECs of CD patients and confirmed using a 3'-untranslated region reporter assay. Activation of ALK1 restricted the proliferation of colonic IECs in a 5-ethynyl-2-deoxyuridine proliferation assay and down-regulated the expression of stemness-related genes. Activated ALK1 signaling increased colonic IEC differentiation toward colonocytes. Down-regulated ALK1 signaling was associated with increased stemness and decreased colonocyte-specific marker expression in colonic IECs of CD patients compared with healthy controls. Activation of ALK1 enhanced epithelial barrier integrity in a transepithelial electrical resistance permeability assay. Lower colonic ALK1 expression was identified as an independent risk factor for surgery and was associated with a higher risk of endoscopic relapse in CD patients.

CONCLUSIONS

Decreased colonic ALK1 disrupted colonic IEC barrier integrity and was associated with poor clinical outcomes in CD patients.

Chronic Antibiotic Dependent Pouchitis Is Associated With Older Age at the Time of Ileal Pouch Anal Anastomosis (J-pouch) Surgery

BACKGROUND

Risk factors for the development of chronic antibiotic dependent pouchitis (CADP) are not well understood.

METHODS

Using multivariable logistic regression, we compared clinical factors between 194 patients with acute antibiotic responsive pouchitis or CADP.

RESULTS

Individuals with CADP were significantly older (40.9 vs 30.8 years, P < 0.001) and demonstrated a longer disease duration before IPAA (10.3 vs 7.0 years, P = 0.004). Age ≥55 years at the time of IPAA was significantly associated with CADP (adjusted odds ratio = 4.35, 95% confidence interval = 1.01-18.7).

CONCLUSIONS

Although older age should not represent a barrier to IPAA, further studies evaluating etiologies of this association are warranted.

Combined Endoscopic and Oral Fecal Microbiota Transplantation in Patients with Antibiotic-Dependent Pouchitis: Low Clinical Efficacy due to Low Donor Microbial Engraftment

Background and Objective

A significant number of pouch patients develop antibiotic-dependent pouchitis (ADP). Microbial dysbiosis is thought to be a major driver of clinical symptoms in ADP. The objective of this proof of concept study was to evaluate safety, efficacy, and donor microbial engraftment of an intensified fecal microbiota transplant (FMT) consisting of a single endoscopic FMT followed by daily oral FMT for 2 weeks in patients with ADP.

Methods

We performed a prospective placebo-controlled double-blind FMT trial in patents with established ADP and planned to enroll 20 patients in this proof of concept study. In case of non-response, patients were offered an optional open label active FMT treatment. The endpoints were safety, clinical remission without need for antibiotics during 16 weeks of follow-up, quantitative changes of fecal calprotectin (FCP), and engraftment of donor FMT as determined by metagenomic sequencing of the V4 region of the 16S rRNA gene.

Results

Due to a lower than expected clinical remission rate and low FMT engraftment, enrollment in the study was stopped prematurely after 6 patients were included. All 6 patients enrolled in the placebo-controlled portion failed to respond and needed antibiotic rescue therapy shortly after FMT. FCP increased in the majority of patients in the setting of relapse after FMT. In the active open label FMT extension study 1 out of 5 patients achieved antibiotic-free clinical remission. FMT engraftment after active FMT was observed only in this single patient, whereas engraftment of donor FMT occurred in none of the other patients receiving active FMT, paralleling the lack of clinical response.

Conclusions

Low donor FMT engraftment resulted in low clinical efficacy of FMT in patients with ADP. Before embarking on larger clinical trials with FMT in patients with ADP or other forms of pouchitis, it is mandatory to explore approaches for superior FMT engraftment.

Bariatric Surgery Is a Safe and Effective Option for Patients with Inflammatory Bowel Diseases: A Case Series and Systematic Review of the Literature

Background

Questions remain regarding both the safety and efficacy of bariatric surgery in patients with inflammatory bowel diseases (IBD), including the effects of bariatric surgery on the course of disease. We report a case series from a tertiary care IBD referral center and review the existing literature regarding the safety and efficacy of bariatric surgery in IBD patients.

Objectives

Examine the safety and efficacy of bariatric surgery in IBD patients. Explore possible effects of weight loss on postoperative IBD course.

Method

We performed a retrospective review of patients at our center undergoing bariatric surgery with a concurrent IBD diagnosis, collecting baseline characteristics, surgery type, and postoperative course (including IBD outcomes and weight loss). Data from these patients were combined with available data from the existing literature to calculate standardized means with standard error, variance, and confidence intervals (CI).

Results

Data from 13 patients who had undergone bariatric surgery at our facility were combined with data from 8 other studies to create a study population of 101 patients. Of these, 61 had Crohn's disease, 37 ulcerative colitis, and 3 IBD-unspecified, with a mean preoperative BMI of 44.2 (95% CI 42.9-45.7). Following surgery, a mean excess weight loss of 68.4% was demonstrated (95% CI, 65.7-71.2). Of the 101 patients, 22 experienced early and 20 experienced late postoperative complications. Postoperatively, 10 patients experienced a flare of IBD, 20 remained in remission, and 7 patients were able to discontinue immunosuppressive therapy.

Conclusions

Based on available studies, bariatric surgery appears to be both an effective and safe option for weight loss in patients with IBD.

Ustekinumab Is Effective for the Treatment of Crohn's Disease of the Pouch in a Multicenter Cohort

BACKGROUND

Crohn's disease (CD) of the pouch and chronic pouchitis occur in approximately 10% of patients after ileal pouch-anal anastomosis (IPAA) for refractory ulcerative colitis (UC) or UC-related dysplasia. The efficacy of anti-tumor necrosis factor (anti-TNF) agents and vedolizumab have been reported for the treatment of CD of the pouch and chronic pouchitis, but little is known regarding the use of ustekinumab in these settings. Our primary aim was to evaluate the efficacy of ustekinumab for these conditions.

METHODS

This is a retrospective, multicenter cohort study evaluating the efficacy of ustekinumab in patients with CD of the pouch and chronic pouchitis. Clinical response or remission was judged by the treating physician's assessment at 6 months.

RESULTS

Fifty-six patients (47 with CD of the pouch and 9 with chronic pouchitis) were included the study. Of these, 73% had previously been treated with either anti-TNF therapy, vedolizumab, or both after IPAA. Among patients with CD of the pouch and chronic pouchitis, 83% demonstrated clinical response 6 months after induction with ustekinumab. Responders demonstrated significantly less pouch inflammation on endoscopy when compared with nonresponders (29% vs 100%; P = 0.023). Higher mean body mass index at induction (26.3 vs 23.7; P = 0.033) and male sex (83% vs 30%; P = 0.014) were significant predictors of nonresponse to ustekinumab in those with CD of the pouch.

CONCLUSION

In this refractory patient population, ustekinumab appears to be a safe and effective treatment for chronic pouchitis and CD of the pouch in biologic-naïve patients and those with prior anti-TNF or vedolizumab therapy failure. 10.1093/ibd/izx005_video1 izy302.video1 5844889626001.

Methotrexate Is Not Superior to Placebo in Maintaining Steroid-Free Response or Remission in Ulcerative Colitis

BACKGROUND & AIMS

Parenteral methotrexate induces clinical remission but not endoscopic improvement of mucosal inflammation in patients with ulcerative colitis (UC). We performed a randomized, placebo-controlled trial to assess the efficacy of parenteral methotrexate in maintaining steroid-free response or remission in patients with UC after induction therapy with methotrexate and steroids.

METHODS

We performed a 48-week trial, from February 2012 through May 2016, of 179 patients with active UC (Mayo score of 6-12 with endoscopy subscore ≥ 2) despite previous conventional or biological therapy. The study comprised a 16-week open label methotrexate induction period followed by a 32-week double-blind, placebo-controlled maintenance period. Patients were given subcutaneous methotrexate (25 mg/wk) and a 12-week steroid taper. At week 16, steroid-free responders were randomly assigned to groups that either continued methotrexate (25 mg/wk, n = 44) or were given placebo (n = 40) until week 48. We compared the efficacy of treatment by analyzing the proportion of patients who remained relapse free and were in remission at week 48 without use of steroids or other medications to control disease activity.

RESULTS

Ninety-one patients (51%) achieved response at week 16, and 84 patients were included in the maintenance period study. During this period, 60% of patients in the placebo group (24/40) and 66% in the methotrexate group (29/44) had a relapse of UC (P = .75). At week 48, 30% of patients in the placebo group (12/40) and 27% of patients in the methotrexate group (12/44) were in steroid-free clinical remission without need for additional therapies (P = .86). No new safety signals for methotrexate were detected.

CONCLUSIONS

Parenteral methotrexate (25 mg/wk) was not superior to placebo in preventing relapses of UC in patients who achieved steroid-free response during induction therapy. ClinicalTrials.gov, Number: NCT01393405.

Correction: ACG Clinical Guideline: Management of Crohn's Disease in Adults

Since the publication of these Guidelines, the authors have noticed an error in the text on page 15. The incorrect statement is.

ACG Clinical Guideline: Management of Crohn's Disease in Adults

Crohn's disease is an idiopathic inflammatory disorder of unknown etiology with genetic, immunologic, and environmental influences. The incidence of Crohn's disease has steadily increased over the past several decades. The diagnosis and treatment of patients with Crohn's disease has evolved since the last practice guideline was published. These guidelines represent the official practice recommendations of the American College of Gastroenterology and were developed under the auspices of the Practice Parameters Committee for the management of adult patients with Crohn's disease. These guidelines are established for clinical practice with the intent of suggesting preferable approaches to particular medical problems as established by interpretation and collation of scientifically valid research, derived from extensive review of published literature. When exercising clinical judgment, health-care providers should incorporate this guideline along with patient's needs, desires, and their values in order to fully and appropriately care for patients with Crohn's disease. This guideline is intended to be flexible, not necessarily indicating the only acceptable approach, and should be distinguished from standards of care that are inflexible and rarely violated. To evaluate the level of evidence and strength of recommendations, we used the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system. The Committee reviews guidelines in depth, with participation from experienced clinicians and others in related fields. The final recommendations are based on the data available at the time of the production of the document and may be updated with pertinent scientific developments at a later time.

Re: Genome-Wide Association Study Identifies African-Specific Susceptibility Loci in African Americans With Inflammatory Bowel Disease

BACKGROUND & AIMS

The inflammatory bowel diseases (IBD) ulcerative colitis (UC) and Crohn’s disease (CD) cause significant morbidity and are increasing in prevalence among all populations, including African Americans. More than 200 susceptibility loci have been identified in populations of predominantly European ancestry, but few loci have been associated with IBD in other ethnicities.

METHODS

We performed 2 high-density, genome-wide scans comprising 2345 cases of African Americans with IBD (1646 with CD, 583 with UC, and 116 inflammatory bowel disease unclassified) and 5002 individuals without IBD (controls, identified from the Health Retirement Study and Kaiser Permanente database). Single-nucleotide polymorphisms (SNPs) associated at P < 5.0 × 10⁻⁸ in meta-analysis with a nominal evidence (P < .05) in each scan were considered to have genome-wide significance.

RESULTS

We detected SNPs at HLA-DRB1, and African-specific SNPs at ZNF649 and LSAMP, with associations of genome-wide significance for UC. We detected SNPs at USP25 with associations of genome-wide significance for IBD. No associations of genome-wide significance were detected for CD. In addition, 9 genes previously associated with IBD contained SNPs with significant evidence for replication (P < 1.6 × 10⁻⁶): ADCY3, CXCR6, HLA-DRB1 to HLA-DQA1 (genome-wide signifi-cance on conditioning), IL12B, PTGER4, and TNC for IBD; IL23R, PTGER4, and SNX20 (in strong linkage disequilibrium with NOD2) for CD; and KCNQ2 (near TNFRSF6B) for UC. Several of these genes, such as TNC (near TNFSF15), CXCR6, and genes associated with IBD at the HLA locus, contained SNPs with unique association patterns with African-specific alleles.

CONCLUSIONS

We performed a genome-wide association study of African Americans with IBD and identified loci associated with UC in only this population; we also replicated IBD, CD, and UC loci identified in European populations. The detection of variants associated with IBD risk in only people of African descent demonstrates the importance of studying the genetics of IBD and other complex diseases in populations beyond those of European ancestry.

Genome-Wide Association Study Identifies African-Specific Susceptibility Loci in African Americans With Inflammatory Bowel Disease

BACKGROUND & AIMS

The inflammatory bowel diseases (IBD) ulcerative colitis (UC) and Crohn's disease (CD) cause significant morbidity and are increasing in prevalence among all populations, including African Americans. More than 200 susceptibility loci have been identified in populations of predominantly European ancestry, but few loci have been associated with IBD in other ethnicities.

METHODS

We performed 2 high-density, genome-wide scans comprising 2345 cases of African Americans with IBD (1646 with CD, 583 with UC, and 116 inflammatory bowel disease unclassified) and 5002 individuals without IBD (controls, identified from the Health Retirement Study and Kaiser Permanente database). Single-nucleotide polymorphisms (SNPs) associated at P < 5.0 × 10^-8 in meta-analysis with a nominal evidence (P < .05) in each scan were considered to have genome-wide significance.

RESULTS

We detected SNPs at HLA-DRB1, and African-specific SNPs at ZNF649 and LSAMP, with associations of genome-wide significance for UC. We detected SNPs at USP25 with associations of genome-wide significance for IBD. No associations of genome-wide significance were detected for CD. In addition, 9 genes previously associated with IBD contained SNPs with significant evidence for replication (P < 1.6 × 10^-6): ADCY3, CXCR6, HLA-DRB1 to HLA-DQA1 (genome-wide significance on conditioning), IL12B,PTGER4, and TNC for IBD; IL23R, PTGER4, and SNX20 (in strong linkage disequilibrium with NOD2) for CD; and KCNQ2 (near TNFRSF6B) for UC. Several of these genes, such as TNC (near TNFSF15), CXCR6, and genes associated with IBD at the HLA locus, contained SNPs with unique association patterns with African-specific alleles.

CONCLUSIONS

We performed a genome-wide association study of African Americans with IBD and identified loci associated with UC in only this population; we also replicated IBD, CD, and UC loci identified in European populations. The detection of variants associated with IBD risk in only people of African descent demonstrates the importance of studying the genetics of IBD and other complex diseases in populations beyond those of European ancestry.

Characterization of genetic loci that affect susceptibility to inflammatory bowel diseases in African Americans

BACKGROUND & AIMS

Inflammatory bowel disease (IBD) has familial aggregation in African Americans (AAs), but little is known about the molecular genetic susceptibility. Mapping studies using the Immunochip genotyping array expand the number of susceptibility loci for IBD in Caucasians to 163, but the contribution of the 163 loci and European admixture to IBD risk in AAs is unclear. We performed a genetic mapping study using the Immunochip to determine whether IBD susceptibility loci in Caucasians also affect risk in AAs and identify new associated loci.

METHODS

We recruited AAs with IBD and without IBD (controls) from 34 IBD centers in the United States; additional controls were collected from 4 other Immunochip studies. Association and admixture loci were mapped for 1088 patients with Crohn's disease, 361 with ulcerative colitis, 62 with IBD type unknown, and 1797 controls; 130,241 autosomal single-nucleotide polymorphisms (SNPs) were analyzed.

RESULTS

The strongest associations were observed between ulcerative colitis and HLA rs9271366 (P = 7.5 × 10(-6)), Crohn's disease and 5p13.1 rs4286721 (P = 3.5 × 10(-6)), and IBD and KAT2A rs730086 (P = 2.3 × 10(-6)). Additional suggestive associations (P < 4.2 × 10(-5)) were observed between Crohn's disease and IBD and African-specific SNPs in STAT5A and STAT3; between IBD and SNPs in IL23R, IL12B, and C2orf43; and between ulcerative colitis and SNPs near HDAC11 and near LINC00994. The latter 3 loci have not been previously associated with IBD, but require replication. Established Caucasian associations were replicated in AAs (P < 3.1 × 10(-4)) at NOD2, IL23R, 5p15.3, and IKZF3. Significant admixture (P < 3.9 × 10(-4)) was observed for 17q12-17q21.31 (IZKF3 through STAT3), 10q11.23-10q21.2, 15q22.2-15q23, and 16p12.2-16p12.1. Network analyses showed significant enrichment (false discovery rate <1 × 10(-5)) in genes that encode members of the JAK-STAT, cytokine, and chemokine signaling pathways, as well those involved in pathogenesis of measles.

CONCLUSIONS

In a genetic analysis of 3308 AA IBD cases and controls, we found that many variants associated with IBD in Caucasians also showed association evidence with these diseases in AAs; we also found evidence for variants and loci not previously associated with IBD. The complex genetic factors that determine risk for or protection against IBD in different populations require further study.

Accuracy of capsule colonoscopy in detecting colorectal polyps in a screening population

BACKGROUND & AIMS

Capsule colonoscopy is a minimally invasive imaging method. We measured the accuracy of this technology in detecting polyps 6 mm or larger in an average-risk screening population.

METHODS

In a prospective study, asymptomatic subjects (n = 884) underwent capsule colonoscopy followed by conventional colonoscopy (the reference) several weeks later, with an endoscopist blinded to capsule results, at 10 centers in the United States and 6 centers in Israel from June 2011 through April 2012. An unblinded colonoscopy was performed on subjects found to have lesions 6 mm or larger by capsule but not conventional colonoscopy.

RESULTS

Among the 884 subjects enrolled, 695 (79%) were included in the analysis of capsule performance for all polyps. There were 77 exclusions (9%) for inadequate cleansing and whole-colon capsule transit time fewer than 40 minutes, 45 exclusions (5%) before capsule ingestion, 15 exclusions (2%) after ingestion and before colonoscopy, and 15 exclusions (2%) for site termination. Capsule colonoscopy identified subjects with 1 or more polyps 6 mm or larger with 81% sensitivity (95% confidence interval [CI], 77%-84%) and 93% specificity (95% CI, 91%-95%), and polyps 10 mm or larger with 80% sensitivity (95% CI, 74%-86%) and 97% specificity (95% CI, 96%-98%). Capsule colonoscopy identified subjects with 1 or more conventional adenomas 6 mm or larger with 88% sensitivity (95% CI, 82%-93) and 82% specificity (95% CI, 80%-83%), and 10 mm or larger with 92% sensitivity (95% CI, 82%-97%) and 95% specificity (95% CI, 94%-95%). Sessile serrated polyps and hyperplastic polyps accounted for 26% and 37%, respectively, of false-negative findings from capsule analyses.

CONCLUSIONS

In an average-risk screening population, technically adequate capsule colonoscopy identified individuals with 1 or more conventional adenomas 6 mm or larger with 88% sensitivity and 82% specificity. Capsule performance seems adequate for patients who cannot undergo colonoscopy or who had incomplete colonoscopies. Additional studies are needed to improve capsule detection of serrated lesions. Clinicaltrials.gov number: NCT01372878.

Methotrexate: underused and ignored?

For more than a decade, methotrexate has been known to be an effective therapeutic agent in the treatment of steroid-dependent active Crohn's disease. However, international data on medication utilization suggest that this drug is rarely used in clinical practice for an indication of Crohn's disease. This review investigates the potential reasons for the underuse of methotrexate in patients with inflammatory bowel diseases.

Contribution of higher risk genes and European admixture to Crohn's disease in African Americans

BACKGROUND

African Americans (AAs) are an admixed population of West African (WA) and European ancestry (EA). Crohn's disease (CD) susceptibility genes have not been established. We therefore evaluated the contribution of European admixture and major established risk genes to AA CD.

METHODS

Ninety-seven admixture informative markers were genotyped for ancestry estimates using STRUCTURE. Overall, 354 AA CD cases and 354 ethnicity-matched controls were genotyped for total 21 single nucleotide polymorphisms (SNPs) in ATG16L1, NOD2, IBD5, IL23R and IRGM by TaqMan or direct sequencing. Association was evaluated by logistic regression, adjusted for ancestry.

RESULTS

Mean EA was similar among the CD cases and controls (20.9% and 20.4%, respectively, P = 0.58). No significant admixture differences were observed among 211 to 227 cases stratified by phenotypic subclassifications including onset, surgery, site, and behavior. CD was associated with NOD2 carrier (6.93% CD, 2.15% Controls, P = 0.007), ATG16L1 Thr300Ala (36.1% CD, 29.3% Controls, P = 0.003), SLC22A4 and SLC22A5 (IBD5 locus) functional SNPs (Leu503Phe [10.5% CD, 7.6% Controls, P = 0.05] and g-207c [41.3% CD, 35.7% Controls, P = 0.03], respectively), and IL23R rs2201841 (18.2% CD, 13.8% Controls, P = 0.03), but not IRGM variants, nor three African ancestral NOD2 nonsynonymous variants. IBD5 risk was recessive. An all-minor allele IBD5 haplotype from EA was associated (P = 0.05), whereas a more common haplotype isolating g-207c was not.

CONCLUSIONS

Specific functional gene variations contribute significantly to AA CD risk. Established NOD2, SLC22A4-A5, and ATG16L1 variants show increased CD risk, with IBD5 recessive. Although CD is more common in whites, European admixture is similar among AA cases and controls.

Conjugated linoleic acid modulates immune responses in patients with mild to moderately active Crohn's disease

BACKGROUND & AIMS

Conjugated linoleic acid (CLA) has demonstrated efficacy as an immune modulator and anti-inflammatory compound in mouse and pig models of colitis. We investigated the immunoregulatory efficacy of CLA in patients with mild to moderate Crohn's disease (CD).

METHODS

Thirteen patients with mild to moderately active CD were enrolled in an open-label study of CLA (6 g/d orally) for 12 weeks. Peripheral blood was collected at baseline, 6 and 12 weeks after treatment initiation for isolation of peripheral blood mononuclear cells for functional analyses of lymphoproliferation and cytokine production. Disease activity was calculated using the CD activity index (CDAI) and quality of life was assessed using the Inflammatory Bowel Disease Questionnaire (IBDQ).

RESULTS

CLA significantly suppressed the ability of peripheral blood CD4+ and CD8+ T cell subsets to produce IFN-γ, TNF-α and IL-17 and lymphoproliferation at week 12. There was a statistically significant drop in CDAI from 245 to 187 (P = 0.013) and increase in IBDQ from 141 to 165 (P = 0.017) on week 12.

CONCLUSION

Oral CLA administration was well tolerated and suppressed the ability of peripheral blood T cells to produce pro-inflammatory cytokines, decreased disease activity and increased the quality of life of patients with CD.

Crohn's disease of the esophagus

Esophageal damage is an uncommon manifestation of Crohn's disease. The diagnosis should be considered in patients who have other intestinal manifestations of Crohn's disease and present with esophageal symptoms. Diagnosis should be based on history, known extraesophageal Crohn's disease, endoscopic evaluation with biopsy, and exclusion of gastroesophageal reflux disease. Mild disease should be treated with acid suppression and a short course of steroids. 5-aminosalicylates are not likely to be effective due to drug release characteristics. Patients who have moderate to severe disease should be treated aggressively with acid suppression, a longer course of steroids, and consideration of immunosuppressive therapy with 6-mercaptopurine or azathioprine. Infliximab or other anti-tumor necrosis factor therapy also can be considered in refractory patients to try to prevent the complications of stricturing and fistula formation. In those patients who develop strictures of the esophagus, treatment with balloon dilatation of the stricture followed by injection of a long-acting steroid such as triamcinolone will help to alleviate symptoms. Surgery may be required for severe, refractory symptoms, but it has a high morbidity in this population.

How rapidly should remission be achieved?

The major goal of therapy in inflammatory bowel disease is to induce remission. Remission has multiple definitions - clinical remission, where the patient's symptoms have remitted, and endoscopic remission, in which there has been complete mucosal healing. Mucosal healing is a harder endpoint of remission but may be more difficult to achieve. In clinical trials we are forced to use activity indices such as the Crohn's disease activity index that may not completely reflect the endoscopic and histologic state of the bowel. Ideally we would like to see remission as quickly as possible to improve patient quality of life. The time to remission varies between different therapeutic approaches. Steroids tend to have a rapid clinical effect with remission seen in some patients as early as two weeks. In early anti-TNF trials, a single dose of infliximab lead to 27% remission at two weeks compared to 4% of placebo patients. Adalimumab and certolizumab have similar reports of early induction of remission. Mesalamine in Crohn's disease has inconsistent and delayed remission rates, whereas in ulcerative colitis, response and remission rates are more consistent in the three-week time frame. Azathioprine and 6-mercaptopurine have delayed onset of action but may induce remission as early as six weeks if dosing is optimized. In this presentation induction of clinical remission and mucosal healing in Crohn's disease and ulcerative colitis will be discussed. The impact of early remission on disease course will also be reviewed.

Efficacy of methotrexate in ulcerative colitis: failure or promise

BACKGROUND

Low-dose methotrexate is a widely used and efficacious therapy in chronic inflammatory disorders such as psoriasis and rheumatoid arthritis. Prospective randomized controlled trials have demonstrated the efficacy of parenteral methotrexate in Crohn's disease (CD). We performed a systematic review of the efficacy of methotrexate in ulcerative colitis (UC) and discuss the results in the context of the known pharmacokinetics and adverse events of methotrexate therapy in inflammatory bowel diseases and other inflammatory conditions.

MATERIALS AND METHODS

We performed a systematic review of the literature in Medline, Embase, and Web of Science. All publications describing patients with UC treated with methotrexate were included.

RESULTS

We identified 12 studies or retrospective case series and 5 meeting abstracts that met the inclusion criteria. Only 1 study reported a prospective randomized placebo-controlled trial using methotrexate at a dose of 12.5 mg orally with no significant clinical benefit. However, the majority of uncontrolled retrospective analyses suggest a clinical response to methotrexate therapy in a range of 30%-80% when the drug is applied by parenteral route in doses between 20-25 mg.

CONCLUSIONS

The only randomized controlled trial of methotrexate in UC employed oral dosing and doses lower than those shown to be effective in CD and did not demonstrate efficacy, whereas uncontrolled, retrospective studies using doses and routes of administration similar to those employed in CD suggest benefit. Well-designed, prospective, placebo-controlled trials of methotrexate in UC are needed.

NOD2 mutations and anti-Saccharomyces cerevisiae antibodies are risk factors for Crohn's disease in African Americans

OBJECTIVES

NOD2 mutations and anti-Saccharomyces cerevisiae antibodies (ASCAs) are established risk factors of Crohn's disease (CD) in whites but have not been assessed in African-American (AA) adults with CD.

METHODS

AAs with CD and controls were recruited by the Mid-Atlantic African-American IBD Study as part of the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) IBD Genetics Consortium. Genotyping for the three common CD NOD2 mutations (Leu1007fsinsC, G908R/2722g>c, and R702W/2104c>t) and ASCA enzyme-linked immunosorbent assays were performed in 183 AA CD patients and in 143 controls. Logistic regression was used to calculate adjusted odds ratios (ORs) for the association between ASCA and disease phenotype.

RESULTS

ASCA sensitivity and specificity values were 70.5 and 70.4%, respectively. On univariate analysis, ASCA was significantly associated with younger age at diagnosis, ileal involvement, and complicated (stricturing/penetrating) behavior. On multivariate analysis, ASCA titer (per 25 Units) was associated with ileal involvement (OR 1.18, 95% confidence interval (CI): 1.04-1.34), complicated behavior (OR 1.13, 95% CI: 1.01-1.28), and surgery (hazard ratio: 1.11, 95% CI: 1.02-1.21). Cigarette smoking and CD family history were also significantly associated with surgery. NOD2 carriers (all heterozygotes) were more common among CD cases than controls (8.2 vs. 2.1%; OR 4.17%, 95% CI: 1.18-14.69). The NOD2 mutation population attributable risk was 6.2%.

CONCLUSIONS

In comparison with whites, ASCA in AAs has a similar sensitivity but a lower specificity for CD. ASCA is associated with ileal involvement, complicated behavior, and surgery in AAs with CD. NOD2 is a risk gene for AA CD, although mutation frequency and population attributable risk are much lower than in whites.

Rifaximin for the treatment of active pouchitis: a randomized, double-blind, placebo-controlled pilot study

BACKGROUND

The efficacy of the nonabsorbable antibiotic rifaximin in patients with active acute or chronic pouchitis is unknown.

METHODS

We performed a placebo-controlled pilot trial to evaluate the efficacy and safety of rifaximin in patients with active pouchitis. Eighteen patients with active pouchitis were randomized to receive oral rifaximin 400 mg or placebo 3 times daily for 4 weeks. Active pouchitis was defined as a total Pouchitis Disease Activity Index (PDAI) score = 7 points. Clinical remission was defined as a PDAI score <7 points and a decrease in the baseline PDAI score = 3 points. The primary analysis was clinical remission at week 4.

RESULTS

Eight patients were randomized to rifaximin and 10 patients were randomized to placebo. One patient in the placebo group did not have a post-baseline efficacy evaluation and was excluded from the efficacy analysis. Two of 8 patients (25%) treated with rifaximin were in clinical remission at week 4 compared to 0 of 9 patients (0%) treated with placebo (P = 0.2059). None of 8 patients in the rifaximin group withdrew from the trial prior to week 4. Two of 9 patients in the placebo group withdrew prior to week 4 due to lack of efficacy and were categorized as treatment failures.

CONCLUSIONS

Clinical remission occurred more frequently in patients treated with rifaximin 400 mg 3 times daily but the difference was not significant in this pilot study. A larger trial would be required to determine if rifaximin is effective for the treatment of active pouchitis. Rifaximin was well tolerated.

A randomized, placebo-controlled, phase II study of tetomilast in active ulcerative colitis

BACKGROUND & AIMS

Tetomilast (OPC-6535), a novel thiazole compound, inhibits phosphodiesterase-4 and proinflammatory functions of leukocytes including superoxide production and cytokine release.

METHODS

One hundred eighty-six patients with mildly to moderately active ulcerative colitis (Disease Activity Index [DAI] 4-11 points) from 35 centers were randomized to receive an oral, once-daily dose of placebo or tetomilast 25 mg or 50 mg for 8 weeks.

RESULTS

Percentages of patients reaching the primary end point (improvement as defined by reduction in DAI > or =3 at week 8) were not significantly different between placebo (35%) and either the 25 mg tetomilast (52%) or the 50 mg tetomilast (39%) groups (intent-to-treat population). Remission rates (DAI 0-1) were 7%, 16%, and 21%, respectively (not significant). Mean reduction in DAI at week 8 was greater in the 25-mg group than under placebo (2.8 +/- 0.4 vs 1.7 +/- 0.36, respectively, P = .041) and approached statistical significance in the 50-mg group (2.8 +/- 0.46, P = .056). A post hoc analysis focusing on patients with high activity scores (baseline DAI 7-11) suggested differences between tetomilast and placebo that will require further investigation. No significant safety concerns were raised. Main adverse effects included gastrointestinal problems (nausea, vomiting) and were preferentially seen in the 50-mg tetomilast group.

CONCLUSIONS

This phase II trial of tetomilast in ulcerative colitis did not achieve statistical significance for the primary end point. Secondary end points indicate a potential clinical activity of tetomilast. The post hoc analysis suggests that further clinical development should focus on patients with objective parameters of inflammation.

State of the art: IBD therapy and clinical trials in IBD

Inflammatory bowel diseases (IBD) encompass Crohn's disease and ulcerative colitis, which are diseases characterized by chronic intestinal inflammation. IBD is believed to result from predisposing genetic and environmental factors (specific antigens and pathogen-associated molecular patterns) acting on the immunoregulatory system and causing inflammation of the gastrointestinal mucosa. IBD may be the result of an imbalance of effector (proinflammatory) and regulatory T-cell responses. Three scenarios indicative of the outcome of this balance exist in animal models: balanced effector and regulatory T cells resulting in a normal controlled inflammation; overactive effector T cells resulting in inflammation and disease; and an absence of regulatory T cells resulting in uncontrolled inflammation and severe, aggressive disease. The number of products under study for the treatment of IBD has increased from 3 products and 1 target in 1993 to more than 30 products and more than 10 targets in 2005. The number of products under development and continued investigations into the pathogenesis of IBD emphasize the need to expand clinical research efforts in IBD.

Ethical issues, safety, and data integrity in clinical trials

Published in 1974, the Belmont Report established the ethical principles for conducting clinical research in the United States. The essential concepts are respect for the research participant, beneficence for society at large, and justice (equal access to participation and equal treatment) toward subjects in a research study. These principles are applied through the use of informed consent, risk/benefit assessment, and the impartial selection of study subjects. Strict adherence to these criteria often results in conflicts of interest, which the investigator must anticipate and manage. Investigators must also be thoroughly acquainted with the principles of Good Clinical Practice and regulatory requirements. Recent implementation of the Privacy Rule now requires the investigator to protect not only the safety but the privacy of the research subject. While the regulatory obligations can appear onerous, strict compliance results in clinical research that is safe, scientifically sound, and ethical.

Design issues and outcomes in IBD clinical trials

Successful clinical trials in inflammatory bowel disease are based on precise definitions of study populations, standardized and well-defined interventions, reliable indices of disease activity, and clearly stipulated outcome measures. Interpretation of research results is often complicated by the differentiation of goals of therapy (remission induction and maintenance, quality of life) and the multitude of patient subsets. Choosing the correct patient subtype to enroll in a clinical trial is critical to the results of a study, its conclusions, and its applicability to the clinical setting. Validated, easy-to-use disease activity indices allow interpretation of results across trials. The use of biomarkers as surrogate clinical endpoints provides reproducibility, ease of statistical handling as a continuous variable, and consistent measurement of response to treatment. Despite these potential advantages, biomarkers of disease activity lack specificity and will need to be validated against clinically meaningful outcomes. Careful subject selection, standardization of disease activity indices, and precise outcome measurement are the keys to continued improvement of the inflammatory bowel disease research process.

Treatment of inflammatory bowel disease with antibiotics

Although antibiotics are clearly recognized as having a role in treating the infectious complications of inflammatory bowel diseases (IBD), their impact in the primary treatment of IBD has long been an area of speculation. Over the past decade there is increasing evidence that luminal gut bacteria play a role in the pathogenesis of IBD, particularly Crohn's disease. Compelling evidence that normal commensal bacteria induce chronic intestinal inflammation in susceptible rodents provides an excellent rationale for treatment of human IBD with antibiotics. This article summarizes published studies of antibiotics in IBD patients and reviews available data for the use of antibiotic therapy in Crohn's disease and ulcerative colitis.

Tacrolimus for the treatment of fistulas in patients with Crohn's disease: a randomized, placebo-controlled trial

BACKGROUND & AIMS

This study determined the effectiveness of tacrolimus for the treatment of Crohn's disease fistulas.

METHODS

The study was a randomized, double-blind, placebo-controlled, multicenter clinical trial. Forty-eight patients with Crohn's disease and draining perianal or enterocutaneous fistulas were randomized to treatment with oral tacrolimus 0.2 mg. kg(-1). day(-1) or placebo for 10 weeks. The primary outcome measure was fistula improvement as defined by closure of >/=50% of particular fistulas that were draining at baseline and maintenance of that closure for at least 4 weeks. A secondary outcome measure was fistula remission as defined by closure of all fistulas and maintenance of that closure for at least 4 weeks.

RESULTS

Forty-three percent of tacrolimus-treated patients had fistula improvement compared with 8% of placebo-treated patients (P = 0.004). Ten percent of tacrolimus-treated patients had fistula remission compared with 8% of placebo-treated patients (P = 0.86). Adverse events significantly associated with tacrolimus, including headache, increased serum creatinine level, insomnia, leg cramps, paresthesias, and tremor, were managed with dose reduction.

CONCLUSIONS

Oral tacrolimus 0.2 mg. kg(-1). day(-1) is effective for fistula improvement, but not fistula remission, in patients with perianal Crohn's disease. Adverse events associated with tacrolimus can be managed by dose reduction. Lower doses of tacrolimus should be evaluated.

Repifermin (keratinocyte growth factor-2) for the treatment of active ulcerative colitis: a randomized, double-blind, placebo-controlled, dose-escalation trial

BACKGROUND

Repifermin (keratinocyte growth factor-2) has been shown to reduce inflammation in animal models of colitis.

AIM

To evaluate repifermin for the treatment of active ulcerative colitis.

METHODS

Eighty-eight patients with active ulcerative colitis were enrolled in a 6-week, double-blind trial. Patients were randomized to receive treatment for five consecutive days with intravenous repifermin at a dose of 1, 5, 10, 25 or 50 microg/kg, or placebo. The primary objective of the study was to evaluate the safety of repifermin. The primary efficacy outcome was clinical remission at week 4, defined as a score of zero on the endoscopic appearance and stool blood components of the Mayo score and a score of zero or unity on the stool frequency and physician's global assessment components.

RESULTS

At week 4, the rates of clinical remission in the 1, 5, 10, 25 and 50 microg/kg repifermin groups were 19%, 9%, 0%, 0% and 0%, respectively, and 11% for the placebo group (P = 0.32 for repifermin vs. placebo). The frequencies of commonly occurring adverse events and severe adverse events were similar in both groups.

CONCLUSIONS

Intravenous repifermin at a dose of 1-50 microg/kg was very well tolerated, but there was no evidence that repifermin was effective for the treatment of active ulcerative colitis at these doses. An additional study to determine the efficacy of repifermin at doses of > 50 microg/kg or for a longer treatment duration may be warranted, as the maximally tolerated dose was not reached in the present study.

Upper gastrointestinal tract endoscopy in inflammatory bowel disease

Upper gastrointestinal endoscopy is used to evaluate upper gastrointestinal symptoms in patients with inflammatory bowel disease. This article discusses the procedure, which may allow for the diagnosis of Crohn's disease of the esophagus, stomach, and/or duodenum. Biopsies of normal gastric mucosa in patients with indeterminate colitis may be helpful in making a diagnosis of Crohn's colitis. Upper gastrointestinal endoscopy may allow for therapeutic intervention in terms of bleeding and stricturing disease.

Hyoscyamine as a pharmacological adjunct in colonoscopy: a randomized, double blinded, placebo-controlled trial

OBJECTIVE

Investigators have assessed the utility of antispasmodic agents in colonoscopy, with conflicting results. The aim of this study is to determine the effects of premedication with hyoscyamine, an anticholinergic antispasmodic, on outcomes in colonoscopy.

METHODS

A total of 165 patients undergoing elective colonoscopy were randomized in a double blinded fashion to one of three arms: intravenous hyoscyamine (0.25 mg), oral hyoscyamine (0.25 mg), or placebo, administered 20-40 min before colonoscopy. Primary outcome measures included insertion time to cecum, patient's assessment of pain, and physician assessment of spasm. Secondary outcome measures included amount of analgesic medications used, total procedure time, amount and type of pathology visualized, and physician assessment of patient's pain.

RESULTS

Bivariate analysis showed no difference between the three groups in insertion time (13.8 min, 14.8 min, and 13.8 min for placebo, intravenous hyoscyamine, and oral hyocyamine, respectively), analgesic medication necessary, or any other primary or secondary outcome variable. Multivariate analysis controlling for potential confounders also failed to demonstrate any differences between the groups. Women had higher procedure duration and analgesic requirement, and reported more pain than did men.

CONCLUSIONS

This randomized, double blinded, placebo-controlled trial did not demonstrate efficacy of either intravenous or oral hyoscyamine as a premedication for colonoscopy.

Lack of effect of intravenous administration on time to respond to azathioprine for steroid-treated Crohn's disease. North American Azathioprine Study Group

BACKGROUND & AIMS

Azathioprine is effective for Crohn's disease but acts slowly. A loading dose may decrease the time to response.

METHODS

A placebo-controlled study was conducted in patients with active Crohn's disease despite prednisone treatment. Patients were randomized to a 36-hour infusion of azathioprine, 40 mg/kg (51 patients), or placebo (45 patients) followed by oral azathioprine, 2 mg/kg, for 16 weeks. Prednisone was tapered over 5 weeks. The primary outcome measure was complete remission at week 8, defined by discontinuation of prednisone and a Crohn's Disease Activity Index of </=150 points. Erythrocyte concentrations of the azathioprine active metabolite, 6-thioguanine nucleotide, were measured.

RESULTS

At week 8, 13 patients (25%) were in complete remission in the azathioprine-loaded group compared with 11 patients (24%) in the placebo group. The frequency of complete remission did not increase after 8 weeks in either group. Both groups achieved steady state of 6-thioguanine nucleotide by week 2, and no differences were found in mean concentrations between the groups. There were no significant differences in the frequency of adverse events between the groups.

CONCLUSIONS

A loading dose does not decrease the time to response in patients with steroid-treated Crohn's disease beginning azathioprine therapy. Steady state of erythrocyte 6-thioguanine nucleotide and complete response occurred earlier than previously reported.

Severe bone pain as an adverse effect of cyclosporin therapy for Crohn's disease

A case of severe bone pain associated with cyclosporin therapy for Crohn's disease is reported. Severe leg pain developed in a 32-year-old man who was receiving cyclosporin for Crohn's disease that was refractory to medical management. Leg pain was related to the dose of cyclosporin, improved with calcium channel blockade, and resolved on discontinuation of cyclosporin. This syndrome has been described in the renal transplantation literature and may be related to vasoconstriction of bone vasculature.

Bioactive and immunoreactive FSH concentrations in ewe and ram lambs over the first year of life

Several studies suggest that the concentration of immunoreactive (I) FSH measured in peripheral plasma by radioimmunoassay does not always reflect the level of bioactive (B) hormone capable of eliciting a biological response (e.g. oestradiol synthesis by Sertoli cells in vitro). The aim of this study was to measure both B-FSH and I-FSH concentrations in male and female sheep during the first year of life, and to relate this to pubertal development. The hypothesis being tested was that B-FSH is present in both male and female sheep during the prepubertal period and that discrete changes in B-FSH are associated with the onset of puberty. Eight ewe lambs and eight rams lambs were blood sampled fortnightly form 2 to 52 weeks of age. All samples were assayed for B-FSH content. Pubertal development was monitored in ewe lambs from behavioural oestrus and from plasma progesterone concentrations, and in ram lambs from penile and testicular development and from plasma testosterone concentrations. Mean I-FSH concentrations varied significantly with time after birth, in both females and males (P < 0.01). In contrast, B-FSH was found to vary with time in females only (P < 0.01). Around the expected time of puberty in ram lambs (i.e. at 30-40 weeks of age), and thereafter, I-FSH concentrations were undetectable (< 0.2 ng ml-1), whereas the B-FSH concentrations were measurable at concentrations up to twice the assay detection limit (0.8 ng ml-1) until 38 weeks of age. In ewe lambs, but not ram lambs, there was a significant linear relationship between B-FSH and I-FSH values (R = 0.595; P < 0.005). When standardised about the time of puberty, B-FSH (P < 0.05) but not I-FSH was significantly higher in ewe lambs that failed to reach puberty. No differences for either B-FSH or I-FSH between pubertal and non-pubertal ram lambs were noted. In summary, B-FSH was soften measurable in plasma throughout prepubertal development in sheep and the concentrations often differed from those of I-FSH, especially in ram lambs. However, there appeared to be no discrete change in B-FSH that could be directly related to specific pubertal events. It is concluded that although FSH may be a prerequisite for prepubertal testicular development and/or ovarian follicular growth, it is not a critical factor in determining whether puberty is attained during the first year of life in this seasonally breeding species.

Pituitary and plasma levels of growth hormone in Booroola sheep that are either homozygous carriers or non-carriers of the FecBB fecundity gene

The aim of this study was to examine the effect of the FecBB fecundity gene on plasma concentrations and pituitary content of growth hormone (GH) in sheep. No differences were found between homozygous carriers (BB) and non carriers (++) of the FecBB gene with regard to pituitary GH contents in both ovariectomized and intact ewes. However, ovariectomized ewes had higher levels of pituitary GH than intact ewes (P < 0.01). There were no differences between FecBB genotypes with respect to plasma concentrations of GH in 6-year-old ovariectomized ewes bled every 10 min for 12 h or in ram lambs bled weekly during their first year of life. GH levels in the rams decreased until week 27, increased to a peak at week 31 then decreased before increasing again at week 43. Mean plasma GH concentrations in the ewe lambs bled weekly for a year decreased until week 19 then remained at approximately this level for the remainder of the year. Mean GH plasma concentrations in the ram lambs were higher than in the ewe lambs (P < 0.001). Ewe lambs that were homozygous for the FecBB gene had lower body weights (P < 0.05) and had higher levels of GH (P < 0.01) than non carrier ewe lambs during their first year. Before the average age of first behavioural oestrus (36 weeks) GH levels in the ewe lambs were negatively correlated with body weights (r = -0.69, P < 0.001, n = 22). When body weight was included as a covariate in analysis of variance the genotype difference in ewe lamb plasma GH concentrations was no longer significant.(ABSTRACT TRUNCATED AT 250 WORDS)

Plasma FSH, LH and immunoreactive inhibin concentrations in FecBB/FecBB and FecB+/FecB+ Booroola ewes and rams from birth to 12 months of age

Endocrine and developmental changes were examined in Booroola FecBB/FecBB (BB, n = 16) and FecB+/FecB+ (++, n = 20) ewe lambs, and BB (n = 17) and ++ (n = 19) ram lambs from 2 to 53 weeks of age. Blood samples were taken weekly for the measurement of plasma concentrations of FSH, LH, immunoreactive inhibin, progesterone (ewe lambs) and testosterone (ram lambs). Behavioural oestrus in the ewe lambs and testicular volume and the breakdown of foreskin adhesions in ram lambs were recorded. Blood samples were taken from another flock of BB (n = 134) and ++ (n = 109) ram lambs at 20 weeks of age for the analysis of immunoreactive inhibin. In ewe and ram lambs, there appeared to be genotype differences for FSH, LH and immunoreactive inhibin at specific times during the neonatal period. In BB and ++ ewe lambs, respectively, mean FSH concentrations were 4.3 and 2.0 ng ml-1 (SED 0.54) between 4 and 6 weeks, 2.6 and 3.4 ng ml-1 (SED 0.33) between 12 and 28 weeks, and 1.8 and 1.9 ng ml-1 (SED 0.18) between 34 and 53 weeks of age. Mean plasma LH concentrations were lower in BB than in ++ ewe lambs from 26 to 53 weeks of age (P < 0.05) but not earlier. Mean concentrations of immunoreactive inhibin were also lower in BB than in ++ ewe lambs between 2 and 11 weeks (16.0 and 27.4 iu ml-1, respectively; P < 0.01), but thereafter no differences were apparent.(ABSTRACT TRUNCATED AT 250 WORDS)

Severe gastrointestinal bleeding

Severe gastrointestinal bleeding is a common cause of admission of the elderly to intensive care units. Differentiation between upper and lower gastrointestinal bleeding is made on the basis of history, physical examination, and diagnostic tests. Therapy is based in part on the severity of the bleeding episode and on the cause of the hemorrhage. Therapeutic intervention may involve medical therapy, endoscopic therapy, angiographic therapy, and surgery. Patient outcome is often related to other underlying disease states.