A142 IMPACT OF HLADQA1*05G>A GENETIC-SCREENING FOR OPTIMAL ANTI-TNF THERAPY IN INFLAMMATORY BOWEL DISEASE: A PRELIMINARY REPORT

Background

Genetic variation in the human leukocyte antigen ( HLA) gene is strongly associated with the formation of anti-drug antibodies to tumor necrosis factor-alpha antagonists (anti-TNF) in inflammatory bowel disease (IBD). It is also associated anti-TNF loss of response and treatment discontinuation.

Aims

We aimed to evaluate the utility of preemptive HLADQA1*05G>A screening to reduce the incidence of treatment-related adverse events in an IBD population by lessening the need for combination therapy in those who do not carry the risk allele. We also assessed for the occurrence of anti-TNF anti-drug antibody (ADA) formation, anti-TNF loss of response, treatment discontinuation compared to an unscreened population.

Methods

A non-randomized open label study is ongoing in IBD patients being considered for anti-TNF therapy. Participants received either pre-treatment HLADQA1*05G>A screening (prospective-screening group, n=25/110 recruited), with the addition of one of azathioprine or methotrexate to anti-TNF therapy (combination therapy) if identified as a high risk variant carrier (G/A or A/A) or received combination therapy without undergoing prospective HLADQA1*05A>G screening (control group, n=25/110 recruited). All participants will be followed for up to 1 year and observed for the occurrence of any adverse drug events, formation of anti-TNF drug antibodies (ADA), anti-TNF loss of response and anti-TNF discontinuation.

Results

To date, the prevalence of HLADQA1*05 G/A and A/A was 20% in the prospective-screening group and thus 20% (n=5/25) received combination therapy and 80% (n=20) received anti-TNF monotherapy. All participants in the control group (n=25/25) received combination therapy. Considering all groups, 78% (n=39/50) received infliximab, while 22% (n=11/50) received adalimumab. To date, the median follow-up period is 5 (IQR=4) months. Fewer adverse drug events have been reported in the prospective-screening group versus the control group (16.7% vs 33.3%, odds ratio 0.40, 95%CI=0.12–1.56, p=0.18). Anti-TNF ADA formation and treatment discontinuation were similar between groups (prospective-screening, 0% versus control, 4.2%). A higher proportion of controls experienced anti-TNF loss of response (16.7% vs 8.3%, p=0.38).

Conclusions

Preemptive HLADQA1*05G>A screening appears to reduce the need for combination therapy when using anti-TNF agents in an IBD population. Fewer drug-related adverse events are reported to date in the screened cohort without a concomitant increase in deleterious outcomes such as ADA formation or anti-TNF discontinuation. Completion of this study will help define whether or not HLADQA1*05G>A-screening is a clinically-actionable and relevant tool for guiding the application of combination therapy in IBD.

Funding Agencies

Lawson Health Research Institute

A12 PRE-TREATMENT HLADQA1-HLADRB1 TESTING FOR THE PREVENTION OF AZATHIOPRINE-INDUCED PANCREATITIS IN INFLAMMATORY BOWEL DISEASE: A PROSPECTIVE COHORT STUDY

Background

Azathioprine (AZA) therapy has a long history of use in IBD. The need to promote its safe use in this population is ensured by governmental health policy requiring IBD patients to fail low cost drugs, such as AZA, prior to approving funding for more potent biologic therapies. AZA-induced pancreatitis is an idiosyncratic and unpredictable response, occurring in up to 7% of AZA-exposed patients that can lead to patient morbidity, hospitalization, delay in effective IBD management, as well as result in substantial additional health-related costs. There are no tools in clinical practice to identify individuals at risk of AZA-induced pancreatitis. Genetic variation in the HLADQA1-HLADRB1*07:01 haplotype is strongly associated with azathioprine (AZA)-induced pancreatitis in inflammatory bowel disease (IBD).

Aims

To evaluate whether HLA DQA1-HLADRB1*07:01A>C pre-treatment genotype testing in an adult IBD population prior to AZA therapy to guide AZA selection would result in a lower incidence of AZA-induced pancreatitis.

Methods

Participants with IBD (n=599) were screened for HLADQA1-HLADRB1*07:01A>C and participants with a variant genotype were excluded from azathioprine treatment (n=271). Wildtype participants (n=328) were started on azathioprine and followed for 3 months. The incidence of pancreatitis was compared to unscreened historical controls (n=373).

Results

The minor allele frequency of HLADQA1-HLADRB1*07:01 was 30.4% and 30.0% in the screened and unscreened populations respectively. Up to 45.2% of participants were excluded from AZA therapy based on genotype in the HLADQA1-HLADRB1*07:01A>C screened cohort. HLADQA1-HLADRB1*07:01A>C screening resulted in an 11-fold reduction in the odds of azathioprine-induced pancreatitis (0.30% versus 3.4%, OR=0.085, 95%CI=0.011–0.651, p=0.002).

Conclusions

HLA DQA1-HLADRB1*07:01A>C screening substantially reduced the risk of pancreatitis during AZA treatment in patients with IBD. However, using this strategy as a tool for guiding the use of AZA therapy in IBD may eliminate a large proportion of patients from being eligible for treatment with AZA. In regions, where there is access to other IBD therapies, and given the short and long term toxicities associated with AZA, HLA DQA1-HLADRB1*07:01A>C screening may be a clinically-relevant strategy for enhancing the safe use of AZA in IBD. Additionally, cost-effectiveness analyses are needed to further solidify the utility of HLA DQA1-HLADRB1*07:01A>C-screening in IBD populations.

Funding Agencies

Academic Medical Organization of Southwestern Ontario Innovation Fund

Screening and Treatment Outcomes in Adults and Children With Type 1 Diabetes and Asymptomatic Celiac Disease: The CD-DIET Study

OBJECTIVE

To describe celiac disease (CD) screening rates and glycemic outcomes of a gluten-free diet (GFD) in patients with type 1 diabetes who are asymptomatic for CD.

RESEARCH DESIGN AND METHODS

Asymptomatic patients (8-45 years) were screened for CD. Biopsy-confirmed CD participants were randomized to GFD or gluten-containing diet (GCD) to assess changes in HbA_1c and continuous glucose monitoring over 12 months.

RESULTS

Adults had higher CD-seropositivity rates than children (6.8% [95% CI 4.9-8.2%, N = 1,298] vs. 4.7% [95% CI 3.4-5.9%, N = 1,089], P = 0.035) with lower rates of prior CD screening (6.9% vs. 44.2%, P < 0.0001). Fifty-one participants were randomized to a GFD (N = 27) or GCD (N = 24). No HbA_1c differences were seen between the groups (+0.14%, 1.5 mmol/mol; 95% CI -0.79 to 1.08; P = 0.76), although greater postprandial glucose increases (4-h +1.5 mmol/L; 95% CI 0.4-2.7; P = 0.014) emerged with a GFD.

CONCLUSIONS

CD is frequently observed in asymptomatic patients with type 1 diabetes, and clinical vigilance is warranted with initiation of a GFD.

Equity and Gender Issues Among Members of the Canadian Association of Gastroenterology

Background

Gender equity has historically been a challenge within gastroenterology.

Aims

The Canadian Association of Gastroenterology (CAG) developed a survey to identify issues pertaining to equity and gender faced by its membership and to determine areas of action.

Methods

In 2014, the survey was emailed to all 1155 CAG members, and the data were analyzed using statistical methods.

Results

One hundred eleven CAG members responded to the survey. Of those, 52% were male, 75% were between 26 and 45 years of age, and 55% were in their first decade of practice. More males held the status of full professor (21% versus 0%; P=0.022). Male CAG members reported working more hours per week than their female counterparts (58.3 ± 15.4 versus 52.3 ± 11.8, P=0.025). Regarding commitments outside the workplace, 81% of respondents had a spouse/partner, and 52% had children under 18 years of age, both of which did not significantly differ based on gender. Overall, 70% were satisfied or very satisfied with their career path. However, significantly more females felt their age/ethnicity/gender/marital status hindered career advancement (36% versus 14%; P=0.008). Furthermore, more females reported difficulties attaining work-life balance (45% versus 22%; P=0.015).

Conclusions

This survey highlights that gender and equity challenges continue to exist within gastroenterology. The needs assessment highlights that work-life balance, physician well-being, negotiation skills and mentorship are areas of importance to many CAG members.

Apixaban and Rosuvas--tatin Pharmacokinetics in Nonalcoholic Fatty Liver Disease

There is little known about the impact of nonalcoholic fatty liver disease (NAFLD) on drug metabolism and transport. We examined the pharmacokinetics of oral apixaban (2.5 mg) and rosuvastatin (5 mg) when administered simultaneously in subjects with magnetic resonance imaging-confirmed NAFLD (N = 22) and healthy control subjects (N = 12). The area under the concentration-time curve to the last sampling time (AUC_0-12) values for apixaban were not different between control and NAFLD subjects (671 and 545 ng/ml × hour, respectively; P = 0.15). Similarly, the AUC_0-12 values for rosuvastatin did not differ between the control and NAFLD groups (25.4 and 20.1 ng/ml × hour, respectively; P = 0.28). Furthermore, hepatic fibrosis in NAFLD subjects was not associated with differences in apixaban or rosuvastatin pharmacokinetics. Decreased systemic exposures for both apixaban and rosuvastatin were associated with increased body weight (P < 0.001 and P < 0.05, respectively). In multivariable linear regression analyses, only participant weight but not NAFLD, age, or SLCO1B1/ABCG2/CYP3A5 genotypes, was associated with apixaban and rosuvastatin AUC_0-12 (P < 0.001 and P = 0.06, respectively). NAFLD does not appear to affect the pharmacokinetics of apixaban or rosuvastatin.

Sitagliptin in patients with non-alcoholic steatohepatitis: A randomized, placebo-controlled trial

AIM

To evaluate the effect of sitagliptin vs placebo on histologic and non-histologic parameters of non-alcoholic steatohepatitis (NASH).

METHODS

Twelve patients with biopsy-proven NASH were randomized to sitagliptin (100 mg daily) (n = 6) or placebo (n = 6) for 24 wk. The primary outcome was improvement in liver fibrosis after 24 wk. Secondary outcomes included evaluation of changes in NAFLD activity score (NAS), individual components of NAS (hepatocyte ballooning, lobular inflammation, and steatosis), glycemic control and insulin resistance [including measurements of glycated hemoglobin (HbA1C) and adipocytokines], lipid profile including free fatty acids, adipose distribution measured using magnetic resonance imaging (MRI), and thrombosis markers (platelet aggregation and plasminogen activator inhibitor 1 levels). We also sought to determine the correlation between changes in hepatic fat fraction (%) [as measured using the Iterative Decomposition of water and fat with Echo Asymmetry and Least-squares estimation (IDEAL) MRI technique] and changes in hepatic steatosis on liver biopsy.

RESULTS

Sitagliptin was not significantly better than placebo at reducing liver fibrosis score as measured on liver biopsy (mean difference between sitagliptin and placebo arms, 0.40, P = 0.82). There were no significant improvements evident with the use of sitagliptin vs placebo for the secondary histologic outcomes of NAS total score as well as for the individual components of NAS. Compared to baseline, those patients who received sitagliptin demonstrated improved HbA1C (6.7% ± 0.4% vs 7.9% ± 1.0%, P = 0.02), and trended towards improved adiponectin levels (4.7 ± 3.5 μg/mL vs 3.9 ± 2.7 μg/mL, P = 0.06) and triglyceride levels (1.26 ± 0.43 mmol/L vs 2.80 ± 1.64 mmol/L, P = 0.08). However, when compared with placebo, sitagliptin did not cause a statistically significant improvement in HbA1C (mean difference, -0.7%, P = 0.19) nor triglyceride levels (mean difference -1.10 mmol/L, P = 0.19) but did trend towards improved adiponectin levels only (mean difference, 0.60 μg/mL, P = 0.095). No significant changes in anthropometrics, liver enzymes, other adipocytokines, lipid profile, thrombosis parameters, or adipose distribution were demonstrated. The MRI IDEAL procedure correlated well with steatosis scores obtained on liver biopsy in both groups at baseline and post-treatment, and the Spearman correlation coefficients ranged from r = 0.819 (baseline) to r = 0.878 (post-treatment), P = 0.002.

CONCLUSION

Sitagliptin does not improve fibrosis score or NAS after 24 wk of therapy. The MRI IDEAL technique may be useful for non-invasive measurement of hepatic steatosis.

A Fibroblast Growth Factor 21-Pregnane X Receptor Pathway Downregulates Hepatic CYP3A4 in Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) alters drug response. We previously reported that NAFLD is associated with reduced in vivo CYP3A drug-metabolism activity and hepatic CYP3A4 expression in humans as well as mouse and human hepatoma models of the disease. Here, we investigated the role of the lipid- and glucose-modulating hormone fibroblast growth factor 21 (FGF21) in the molecular mechanism regulating CYP3A4 expression in NAFLD. In human subjects, mouse and cellular NAFLD models with lower CYP3A4 expression, circulating FGF21, or hepatic FGF21 mRNA levels were elevated. Administration of recombinant FGF21 or transient hepatic overexpression of FGF21 resulted in reduced liver CYP3A4 luciferase reporter activity in mice and decreased CYP3A4 mRNA expression and activity in cultured Huh7 hepatoma cells. Blocking canonical FGF21 signaling by pharmacological inhibition of MEK1 kinase in Huh7 cells caused de-repression of CYP3A4 mRNA expression with FGF21 treatment. Mice with high-fat diet-induced simple hepatic steatosis and lipid-loaded Huh7 cells had reduced nuclear localization of the pregnane X receptor (PXR), a key transcriptional regulator of CYP3A4 Furthermore, decreased nuclear PXR was observed in mouse liver and Huh7 cells after FGF21 treatment or FGF21 overexpression. Decreased PXR binding to the CYP3A4 proximal promoter was found in FGF21-treated Huh7 cells. An FGF21-PXR signaling pathway may be involved in decreased hepatic CYP3A4 metabolic activity in NAFLD.

Management of non-alcoholic fatty liver disease in 2015

There is no single pharmacologic therapy that has been approved to treat nonalcoholic fatty liver disease in the general population. The backbone of therapy currently includes intensive lifestyle modification with established targets for diet and weight loss. The use of unsweetened, unfiltered coffee along with limiting high fructose corn syrup have emerged as beneficial dietary recommendations. The use of empiric oral hypoglycemic agents and vitamin E, however, has not been widely accepted. Developing bariatric surgical techniques are promising, but additional studies with long-term follow up are needed before it can be widely recommended. Finally, liver transplantation is an increasingly frequent consideration once complications of end-stage disease have developed. The future treatment of those with nonalcoholic fatty liver disease will likely involve a personalized approach. The importance of the gut microbiome in mediating hepatocyte inflammation and intestinal permeability is emerging and may offer avenues for novel treatment. The study of anti-fibrotic agents such as pentoxifylline and FXR agonists hold promise and new pathways, such as hepatocyte cannabinoid receptor antagonists are being studied. With the incidence of obesity and the metabolic syndrome increasing throughout the developed world, the future will continue to focus on finding novel agents and new applications of existing therapies to help prevent and to mediate the progression of nonalcoholic fatty liver disease.

The Celiac Disease and Diabetes-Dietary Intervention and Evaluation Trial (CD-DIET) protocol: a randomised controlled study to evaluate treatment of asymptomatic coeliac disease in type 1 diabetes

INTRODUCTION

Coeliac disease (CD) is an autoimmune condition characterised by gluten-induced intestinal inflammation, and observed at a 5-10 fold greater prevalence in type 1 diabetes. While universal screening for CD in patients with diabetes is frequently advocated, objective data is limited as to benefits on diabetes control, bone health or quality of life related to the adoption of a gluten-free diet (GFD) in the large proportion of patients with diabetes with asymptomatic CD. The Celiac Disease and Diabetes-Dietary Intervention and Evaluation Trial (CD-DIET) study is a multicenter, randomised controlled trial to evaluate the efficacy and safety of a GFD in patients with type 1 diabetes with asymptomatic CD.

METHODS AND ANALYSIS

Children and adults (8-45 years) with type 1 diabetes will be screened for asymptomatic CD. Eligible patients with biopsy-proven CD will be randomly assigned in a 1:1 ratio to treatment with a GFD for 1 year, or continue with a gluten-containing diet. The primary outcome will evaluate the impact of the GFD on change in glycated haemoglobin. Secondary outcomes will evaluate changes in bone mineral density, blood glucose variability and health-related quality of life between GFD-treated and the regular diet group over a 1-year period. The study was initiated in 2012 and has subsequently expanded to multiple paediatric and adult centres in Ontario, Canada.

ETHICS AND DISSEMINATION

The findings from this study will provide high-quality evidence as to the impact of GFD treatment on glycaemic control and complications in asymptomatic children and adults with CD and type 1 diabetes.

TRIAL REGISTRATION NUMBER

NCT01566110.

Inflammation is not the cause of an elevated serum ferritin in non-alcoholic fatty liver disease

BACKGROUND

In non-alcoholic fatty liver disease (NALFD), it has often been assumed that an elevation in serum ferritin is likely related to inflammation rather than iron overload.

MATERIAL AND METHODS

Patients referred with NAFLD were entered into a clinical study of phlebotomy therapy. A liver biopsy with liver iron concentration was done at entry and 6 months after phlebotomy (n = 56) until the patient had a low serum ferritin or developed anemia. Serum ferritin was compared to liver iron concentration, ESR, CRP, BMI and grade of inflammation on liver biopsy.

RESULTS

Iron removed by phlebotomy in NAFLD correlated with the decrease in serum ferritin (r = 0.57, p = 0.0014) and liver iron concentration (r = 0.57, p = 0.0013). There was no significant correlations between serum ferritin and ESR, CRP or grade of liver inflammation.

CONCLUSIONS

Serum ferritin is related to liver iron storage in NAFLD and decreasing body iron stores by phlebotomy is reflected by an appropriate decrease in serum ferritin. Inflammation is not the cause of the elevated serum ferritin in fatty liver disease.

Phase II clinical trial of phlebotomy for non-alcoholic fatty liver disease

BACKGROUND

Elevated iron indices are described in non-alcoholic fatty liver disease and iron reduction has been suggested as a potential therapy.

AIM

To determine whether phlebotomy is an effective therapy for non-alcoholic fatty liver disease.

METHODS

Patients with biopsy proven non-alcoholic fatty liver disease underwent baseline evaluation to determine severity of metabolic and liver disease. A Phase II trial of phlebotomy was carried out to achieve near-iron depletion (serum ferritin ≤50 μg/L or haemoglobin 100 g/L). Repeat liver biopsy, anthropometric and biochemical measurements were performed 6 months following the end of treatment. Primary outcome was improvement in liver histology, assessed using the non-alcoholic fatty liver disease activity score.

RESULTS

Thirty-one patients completed follow-up. Iron reduction resulted in a significant improvement in the non-alcoholic fatty liver disease activity score (-0.74 ± 1.83, P = 0.019). Reductions in individual histological features of lobular inflammation (-0.29 ± 1.07, P = 0.182), steatosis (-0.26 ± 0.82, P = 0.134), hepatocyte ballooning (-0.19 ± 0.70, P = 0.213) did not achieve significance nor did the score for fibrosis (-0.32 ± 0.94, P = 0.099).

CONCLUSIONS

This prospective Phase II study of phlebotomy with paired liver biopsies evaluating phlebotomy therapy in non-alcoholic fatty liver disease patients suggests that iron reduction may improve liver histology. However, the effect size of phlebotomy raises questions of whether treatment could have sufficient clinical significance to justify a definitive Phase III trial. This trial has been registered with the US National Institute of Health (clinicaltrials.gov, Identifier NCT 00641524).

Treatment of hyperferritinemia

Elevated serum ferritin, or hyperferritinemia, is a common finding on routine bloodwork and often prompts referral for further evaluation. In the following review, we outline the various causes of hyperferritinemia and point out that, in the majority of cases, this does not represent true iron overload. Despite much research interest in this area, the precise mechanism of hyperferritinemia and its impact on disease severity in various clinical conditions continues to be debated. While some research suggests that iron reduction in cases of hyperferritinemia is of benefit, the decision to treat such patients should be individualized, and may be influenced by the presence of other features of iron overload.

Current treatment options for nonalcoholic fatty liver disease and nonalcoholic steatohepatitis

Nonalcoholic fatty liver disease is the leading cause of liver disease in western society. It is a cause of end-stage liver disease, with increased mortality secondary to cirrhosis and its complications. It is also recognized that cardiovascular disease is a significant cause of death in these patients. Significant work evaluating various treatments has been performed in recent years; however, to date, no ideal therapy exists. Lifestyle modification remains the cornerstone of management. The present article reviews the current status of various treatment modalities evaluated in nonalcoholic fatty liver disease.

The myths and realities of hemochromatosis

Hemochromatosis is a common genetic condition and yet there are still a number of misperceptions surrounding the diagnosis and management of this condition. Hemochromatosis affects both men and women. Typical patients do not have alcoholism or viral hepatitis, and often have normal liver enzymes. Clinical expression is highly variable. Genetic testing is widely available and particularly useful in family studies. Hemochromatosis can be readily diagnosed and treated. The purpose of the present review is to address the medical myths and misconceptions of hemochromatosis.

Prognostic factors and survival in patients with hereditary hemochromatosis and cirrhosis

OBJECTIVES

The survival of treated, noncirrhotic patients with hereditary hemochromatosis is similar to that of the general population. Less is known about the outcome of cirrhotic hereditary hemochromatosis patients. The present study evaluated the survival of patients with hereditary hemochromatosis and cirrhosis.

METHODS

From an established hereditary hemochromatosis database, all cirrhotic patients diagnosed from January 1972 to August 2004 were identified. Factors associated with survival were determined using univariate and multivariate regression. Survival differences were assessed using the Kaplan-Meier life table method.

RESULTS

Ninety-five patients were identified. Sixty patients had genetic testing, 52 patients (87%) were C282Y homozygotes. Median follow-up was 9.2 years (range 0 to 30 years). Nineteen patients (20%) developed hepatocellular carcinoma, one of whom was still living following transplantation. Cumulative survival for all patients was 88% at one year, 69% at five years and 56% at 20 years. Factors associated with death on multivariate analysis included advanced Child-Pugh score and hepatocellular carcinoma. Patients with hepatocellular carcinoma were older at the time of diagnosis of cirrhosis (mean age 61 and 54.6 years, respectively; P=0.03). The mean age at the time of diagnosis of hepatocellular carcinoma was 70 years (range 48 to 79 years). No other differences were found between the groups.

CONCLUSIONS

Patients with hereditary hemochromatosis and cirrhosis are at significant risk of developing hepatocellular carcinoma. These patients are older when diagnosed with carcinoma and may have poorer survival following transplantation than patients with other causes of liver disease. Early diagnosis and treatment of hereditary hemochromatosis by preventing the development of cirrhosis may reduce the incidence of hepatocellular carcinoma in the future.