Effect of Early Versus Late Azathioprine Therapy in Pediatric Ulcerative Colitis

Thiopurines Maintenance Therapy in Children With Ulcerative Colitis: A Multicenter Retrospective Study

BACKGROUND AND AIMS

Thiopurines are an established treatment for pediatric ulcerative colitis (UC). However, data regarding safety and efficacy are lacking. We aimed to determine short and long-term outcome following thiopurines use in children with UC.

METHODS

We conducted a retrospective review of children (2-18 years) with UC treated with thiopurines between January 2008 and January 2019 at 7 medical centers in Israel. The primary outcome was corticosteroid (CS)-free clinical remission at week 52 following thiopurines initiation without the need for rescue therapy (infliximab, calcineurin inhibitors, or colectomy).

RESULTS

A total of 133 children were included [median age at diagnosis of 12.4 (interquartile range 11.0-15.8) years, 30 (23%) left-sided colitis, 113 (85%) with moderate or severe disease at diagnosis]. At diagnosis 58 patients (44%) were treated with 5-aminosalicylates and 72 (54%) with CS. Sixty patients (45%) received thiopurines as 1st line maintenance therapy. Seventy-four patients (56%) had CS-free clinical remission at week 52 without rescue therapy. Predictors of clinical remission were not identified. In a sub-analysis among patients with steroid-responsive moderate to severe UC, 59 (55%) patients achieved this outcome. The likelihood of remaining free of rescue therapy among thiopurines-treated patients was 83%, 62%, 45%, and 37% at 1, 2, 3, and 4 years, respectively.

CONCLUSION

More than half of children with UC starting thiopurines without previous or concomitant biologic therapy have CS-free clinical remission at 52 weeks later without the need for rescue therapy. Thiopurines are effective in pediatric UC and could be considered prior to biologics.

Hydrogel-encapsulation to enhance bacterial diagnosis of colon inflammation

Bacteria can be genetically programmed to sense and report the presence of disease biomarkers in the gastrointestinal (GI) tract. However, diagnostic bacteria are typically delivered via oral administration of liquid cultures, resulting in poor survival and high dispersal in vivo. These limitations confound recovery and analysis of engineered bacteria from GI or stool samples. Here, we demonstrate that encapsulating bacteria inside of alginate core-shell particles enables robust survival, containment, and diagnostic function in vivo. We demonstrate these benefits by encapsulating a strain engineered to report the presence of the biomarker thiosulfate via fluorescent protein expression in order to diagnose dextran sodium sulfate-induced colitis in rats. Hydrogel-encapsulated bacteria engineered to sense and respond to physiological stimuli should enable minimally invasive monitoring of a wide range of diseases and have applications as next-generation smart therapeutics.

Choosing the Right Therapy at the Right Time for Pediatric Inflammatory Bowel Disease: Does Sequence Matter

Despite the enlarging therapeutic armamentarium, IBD is still plagued by a therapeutic ceiling. Precision medicine, with the selection of the "rights," may present a solution, and this review will discuss the critical process of pairing the right patient with right therapy at the right time. Firstly, the review will discuss the shift to and evidence behind early effective therapy. Then, it delves into promising future strategies of patient profiling to identify a patients' biological pathway(s) and prognosis. Finally, the review lays out practical considerations that drive treatment selection, particularly the impact of the therapeutic sequence.

Thiopurines in Pediatric Inflammatory Bowel Disease: Current and Future Place

Thiopurines have been widely used to maintain steroid-free remission in children with inflammatory bowel disease (IBD). However, within the expanding treatment armamentarium, the role of these non-selective immunomodulators has been questioned, especially in pediatric patients, who often present with a more aggressive disease course, which can impact growth and development. The less favorable safety but also inferior efficacy profile associated with thiopurines, in contrast to the newer biological therapies, has interfered with their use. The future place of thiopurines in the management of childhood IBD, therefore, needs revisiting. This review provides a practical overview on the historical and current use of thiopurines in pediatric IBD with specific attention for thiopurine S-methyltransferase testing and monitoring of thiopurine metabolite levels as an approach to improve outcomes. We also give a personal expert opinion on the future role of these drugs in childhood IBD.

Prevalence and duration of gastrointestinal symptoms before diagnosis of Inflammatory Bowel Disease and predictors of timely specialist review: a population-based study

BACKGROUND AND AIMS

Lack of timely referral and significant waits for specialist review amongst individuals with unresolved gastrointestinal (GI) symptoms can result in delayed diagnosis of Inflammatory Bowel Disease (IBD).

AIMS

To determine the frequency and duration of GI symptoms and predictors of timely specialist review before the diagnosis of both Crohn's Disease (CD) and ulcerative colitis (UC).

METHODS

Case-control study of IBD matched 1:4 for age and sex to controls without IBD using the Clinical Practice Research Datalink from 1998-2016.

RESULTS

We identified 19,555 cases of IBD, and 78,114 controls. 1 in 4 cases of IBD reported gastrointestinal symptoms to their primary care physician more than 6 months before receiving a diagnosis. There is a significant excess prevalence of GI symptoms in each of the 10 years before IBD diagnosis. GI symptoms were reported by 9.6% and 10.4% at 5 years before CD and UC diagnosis respectively compared to 5.8% of controls. Amongst patients later diagnosed with IBD, <50% received specialist review within 18 months from presenting with chronic GI symptoms. Patients with a previous diagnosis of irritable bowel syndrome or depression were less likely to receive timely specialist review (IBS: HR=0.77, 95%CI 0.60-0.99, depression: HR=0.77, 95%CI 0.60-0.98).

CONCLUSIONS

There is an excess of GI symptoms 5 years before diagnosis of IBD compared to the background population which are likely attributable to undiagnosed disease. Previous diagnoses of IBS and depression are associated with delays in specialist review. Enhanced pathways are needed to accelerate specialist referral and timely IBD diagnosis.

Long-term outcome of immunomodulator use in pediatric patients with inflammatory bowel disease

OBJECTIVES

In the era where new biologicals are entering the market, the place of immunomodulators in the treatment of pediatric inflammatory bowel disease (IBD) needs to be reassessed.

METHODS

All children with Crohn's disease (CD) or ulcerative colitis (UC) followed at our center over the last 10 years were reviewed. Children who received conventional therapy (including 5-aminosalicylates, steroids, thiopurines and methotrexate) since diagnosis were included. Primary outcome was steroid-free clinical remission without need for rescue therapy (biologics or surgery) at 6 and 12 months after diagnosis and at last follow-up. Cox proportional hazard modelling was performed to determine variables at diagnosis associated with outcomes.

RESULTS

In total, 176 IBD patients (121 CD, 55 UC) were identified with a median follow-up of 4.6 [2.0-8.1] years. Remission rates were 79.6% at month 6, but decreased to 60.2% at month 12, and 31.8% at last follow-up. Higher CRP [1.006 (1.001-1.011)], lower albumin [1.050 (1.012-1.086)] and growth impairment [1.214 (1.014-1.373)] in CD patients and higher PUCAI score [1.038 (1.006-1.072)] and low iron [1.023 (1.003-1.043)] in UC patients were associated with treatment failure (all p < 0.05).

CONCLUSION

Only 32% pediatric IBD patients will remain free of biologics or surgery 5-years after diagnosis. Especially children with a high disease burden at diagnosis were more likely to fail conventional therapy.

Impact of Changing Treatment Strategies on Outcomes in Pediatric Ulcerative Colitis

BACKGROUND

In recent years, treatment strategies for ulcerative colitis have evolved with an early step-up approach, the availability of biologicals, and therapeutic drug monitoring.We carried out this study to evaluate the effect of these changes on disease outcomes.

METHODS

In this retrospective review, 2 time periods were defined: Group 1 (2005-2010) and Group 2 (2011-2016). Baseline demographic, endoscopic parameters, and medication use were compared. Overall colectomy rate, number of disease flares per year, and number of hospital admissions per year were compared between the 2 groups.

RESULTS

Group 1 had 71 children, and in children in Group 2. The use of 5-ASA increased in Group 2 (Group 2, 99.2% vs. Group 1, 84.5%, P = 0.0007). In addition, infliximab and thiopurines were introduced earlier in the disease course.The 2-year cumulative probability of colectomy decreased from 14% to 3% (P = 0.02) between the 2 periods. No change in median number of flares per year [Group 1, 0.41 (IQR 0.6) vs. Group 2, 0.62 (IQR 0.91), P = 0.28] or median number of hospital admissions per year [Group 1, 0.30 (IQR 0.77) vs. Group 2, 0.21 (IQR 0.75), P = 0.52] was seen.Thereafter, we proceeded to identify the changes in treatment strategies that were responsible for the reduction in colectomy and we found that the use of infliximab OR 3.7 (95% CI 1.1-11.7), P = 0.02, was independently associated with it.

CONCLUSIONS

A reduction in 2-year colectomy rates has been observed in patients with pediatric ulcerative colitis since biologics have become available for its treatment. The numbers of disease-flares rates and hospital admissions remain unchanged.

Association between use of azathioprine and risk of acute pancreatitis in children with inflammatory bowel disease: a Swedish-Danish nationwide cohort study

BACKGROUND

Studies have shown an association between use of azathioprine and increased risk of acute pancreatitis in adult inflammatory bowel disease. However, whether an association exists among paediatric patients is not known. We aimed to investigate whether use of azathioprine is associated with the risk of acute pancreatitis in children with inflammatory bowel disease.

METHODS

We did a nationwide register-based cohort study in Sweden (2006-16) and Denmark (2000-16). All paediatric patients (<18 years of age) with inflammatory bowel disease during the study period were identified through hospital records. Episodes of incident azathioprine use and no use of any thiopurine were matched (1:1) using propensity scores, controlling for sociodemographic characteristics, comorbidities, previous treatment, indicators of disease severity, and health care use. Incident acute pancreatitis (physician-assigned diagnosis with ICD-10 code K85) occurring in the 90 days following treatment initiation were identified through outpatient and inpatient hospital records.

FINDINGS

We identified 3574 azathioprine episodes and 18 700 no-use episodes, which resulted in 3374 pairs after propensity score matching; baseline characteristics in the matched cohort were well balanced. Among the matched azathioprine episodes, mean age was 14·3 years (SD 3·1), 1854 (54·9%) were male, 1923 (57·0%) had Crohn's disease, and 1451 (43·0%) had ulcerative colitis or unclassified inflammatory bowel disease. Within the first 90 days following initiation of azathioprine, 40 acute pancreatitis events occurred (incidence rate 49·1 events per 1000 person-years) compared with six events in the no-use group (8·4 events per 1000 person-years). Azathioprine use was associated with an increased risk of acute pancreatitis (incidence rate ratio 5·82 [95% CI 2·47-13·72]; absolute difference 1·0 [95% CI 0·3-2·6] events per 100 patients) during the 90-day risk period.

INTERPRETATION

Use of azathioprine was associated with an increased risk of acute pancreatitis in children with inflammatory bowel disease during the first 90 days following treatment initiation, suggesting the need for regular and rigorous monitoring. The risk of acute pancreatitis needs to be considered when deciding on optimal treatment strategies.

FUNDING

Swedish Research Council, Frimurare Barnhuset Foundation, and the Åke Wiberg Foundation.

Management of Paediatric Ulcerative Colitis, Part 1: Ambulatory Care-An Evidence-based Guideline From European Crohn's and Colitis Organization and European Society of Paediatric Gastroenterology, Hepatology and Nutrition

BACKGROUND

The contemporary management of ambulatory ulcerative colitis (UC) continues to be challenging with ∼20% of children needing a colectomy within childhood years. We thus aimed to standardize daily treatment of pediatric UC and inflammatory bowel diseases (IBD)-unclassified through detailed recommendations and practice points.

METHODS

These guidelines are a joint effort of the European Crohn's and Colitis Organization (ECCO) and the Paediatric IBD Porto group of European Society of Paediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN). An extensive literature search with subsequent evidence appraisal using robust methodology was performed before 2 face-to-face meetings. All 40 included recommendations and 86 practice points were endorsed by 43 experts in Paediatric IBD with at least an 88% consensus rate.

RESULTS

These guidelines discuss how to optimize the use of mesalamine (including topical), systemic and locally active steroids, thiopurines and, for more severe disease, biologics. The use of other emerging therapies and the role of surgery are also covered. Algorithms are provided to aid therapeutic decision-making based on clinical assessment and the Paediatric UC Activity Index (PUCAI). Advice on contemporary therapeutic targets incorporating the use of calprotectin and the role of therapeutic drug monitoring are presented, as well as other management considerations around pouchitis, extraintestinal manifestations, nutrition, growth, psychology, and transition. A brief section on disease classification using the PIBD-classes criteria and IBD-unclassified is also part of these guidelines.

CONCLUSIONS

These guidelines provide a guide to clinicians managing children with UC and IBD-unclassified management to provide modern management strategies while maintaining vigilance around appropriate outcomes and safety issues.

Risk of Colectomy in Patients With Pediatric-onset Ulcerative Colitis

OBJECTIVES

Data describing the incidence and risk factors for colectomy in pediatric ulcerative colitis (UC) is inconsistent. Our aim was to describe the colectomy rate and to identify risk factors associated with colectomy in a large cohort of children with UC with long-term follow-up.

MATERIALS AND METHODS

We performed a retrospective chart review of pediatric UC cases that were diagnosed at Schneider Children's Medical Center of Israel between 1981 and 2013. Potential predictors for colectomy including age at diagnosis, sex, disease extent, severity indices, and different therapeutic regimens during disease course were assessed.

RESULTS

Of 188 patients with pediatric onset UC, 34 (18%) underwent colectomy. Median follow-up was 6.9 years (range, 1-30). Kaplan-Meier survival estimates of the cumulative probability for colectomy were 4% at 1 year and 17% at 10 years from diagnosis. Multivariate Cox models showed that male sex (hazard ratio 4.2, P = 0.001) and severe disease at diagnosis reflected by Pediatric Ulcerative Colitis Activity Index score ≥65 (hazard ratio 8.9, P < 0.001) were associated with increased risk for colectomy. Age, disease extent, ethnicity, family history of inflammatory bowel disease, early introduction of immunomodulators, or treatment with antitumor necrosis factor α agent did not affect the risk of colectomy.

CONCLUSIONS

Male sex and higher Pediatric Ulcerative Colitis Activity Index score at diagnosis are independent risk factors for colectomy.

Multicentric Case-Control Study on Azathioprine Dose and Pharmacokinetics in Early-onset Pediatric Inflammatory Bowel Disease

BACKGROUND

Early-onset inflammatory bowel disease (IBD) is generally aggressive, with a high probability of complications and need of surgery. Despite the introduction of highly effective biological drugs, treatment with azathioprine continues to be important even for early-onset IBD; however, in these patients azathioprine response seems to be reduced. This study evaluated azathioprine doses, metabolite concentrations, and their associations with patients' age in children with IBD treated at 6 tertiary pediatric referral centers.

METHODS

Azathioprine doses, metabolites, and clinical effects were assessed after at least 3 months of therapy in 17 early-onset (age < 6 yr, cases) and 51 nonearly-onset (aged > 12 and <18 yrs, controls) patients with IBD. Azathioprine dose was titrated on therapeutic efficacy (response and adverse effects). Azathioprine metabolites and thiopurine methyltransferase activity were determined by high-performance liquid chromatography with ultra violet-vis detection (HPLC-UV) methods.

RESULTS

Frequency of patients in remission was similar among early-onset and control groups, respectively (82% and 84%, P value = 0.72). Early-onset patients required higher doses of azathioprine (median 2.7 versus 2.0 mg·kg·d, P value = 1.1 × 10). Different doses resulted in comparable azathioprine active thioguanine nucleotide metabolite concentrations (median 263 versus 366 pmol/8 × 10 erythrocytes, P value = 0.41) and methylmercaptopurine nucleotide concentrations (median 1455 versus 1532 pmol/8 × 10 erythrocytes, P value = 0.60). Lower ratios between thioguanine nucleotide metabolites and azathioprine doses were found in early-onset patients (median 98 versus 184 pmol/8 × 10 erythrocytes·mg·kg·d, P value = 0.017). Interestingly, early-onset patients presented also higher thiopurine methyltransferase activity (median 476 versus 350 nmol methylmercaptopurine/mg hemoglobin/h, P-value = 0.046).

CONCLUSIONS

This study demonstrated that patients with early-onset IBD present increased inactivating azathioprine metabolism, likely because of elevated activity of the enzyme thiopurine methyltransferase.

Mucosal Healing in Ulcerative Colitis: A Comprehensive Review

Ulcerative colitis (UC) is a chronic inflammatory bowel disease characterized by periods of remission and periods of relapse. Patients often present with symptoms such as rectal bleeding, diarrhea and weight loss, and may require hospitalization and even colectomy. Long-term complications of UC include decreased quality of life and productivity and an increased risk of colorectal cancer. Mucosal healing (MH) has gained progressive importance in the management of UC patients. In this article, we review the endoscopic findings that define both mucosal injury and MH, and the strengths and limitations of the scoring systems currently available in clinical practice. The basic mechanisms behind colonic injury and MH are covered, highlighting the pathways through which different drugs exert their effect towards reducing inflammation and promoting epithelial repair. A comprehensive review of the evidence for approved drugs for UC to achieve and maintain MH is provided, including a section on the pharmacokinetics of anti-tumor necrosis factor (TNF)-α drugs. Currently approved drugs with proven efficacy in achieving MH in UC include salicylates, corticosteroids (induction only), calcineurin inhibitors (induction only), thiopurines, vedolizumab and anti-TNFα drugs (infliximab, adalimumab, and golimumab). MH is of crucial relevance in the outcomes of UC, resulting in lower incidences of clinical relapse, the need for hospitalization and surgery, as well as reduced rates of dysplasia and colorectal cancer. Finally, we present recent evidence towards the need for a more strict definition of complete MH as the preferred endpoint for UC patients, using a combination of both endoscopic and histological findings.