Quality of reporting inflammatory bowel disease randomised controlled trials: a systematic review

OBJECTIVE

Our objective was to perform a systemic evaluation of the risk of bias in randomised controlled trial (RCT) reports published on inflammatory bowel disease (IBD).

DESIGN

We assessed the risk of bias using the Cochrane tool, as indicators of poor methodology or subsequently poor reporting. We systematically selected, with dual independent judgements, all studies published on IBD with no time limits and assessed the methodological quality of included studies again using independent dual ratings.

RESULTS

563 full texts were included after selection and review. No abstract publications were free of any source of bias. Full-text publications still fared badly, as only 103 full-text papers exhibited a low risk of bias in all reporting domains when excluding blinding. RCTs published in journals with higher impact factor (IF) were associated with an overall reduced rate of being at high risk. However, only 6% of full RCT publications in journals with an IF greater than 10, published in the past 5 years, were free of bias.The trend over time is towards improved reporting in all areas. Trials published by larger author teams, in full-text form and by industry and public sponsorship were positively correlated with a lower risk of bias. Only allocation concealment showed a statistically significant improvement with time (p=0.037).

CONCLUSION

These findings are consistent with those of other specialties in the literature. While this unclear risk of bias may represent poor reporting of methods instead of poor methodological quality, it leaves readers and future secondary researchers with significant questions regarding such key issues.

Early-life exposures and the microbiome: implications for IBD prevention

The early-life period is one of microbiome establishment and immune maturation. Early-life exposures are increasingly being recognised to play an important role in IBD risk. The composition of functions of the gut microbiome in the prenatal, perinatal, and postnatal period may be crucial towards development of health or disease, including IBD, later in life. We herein present a comprehensive summary of the interplay between early-life factors and microbiome perturbations, and their association with risk of IBD. In addition, we provide an overview of host and external factors in early life that are known to impact gut microbiome maturation and exposures implicated in IBD risk. Considering the emerging concept of IBD prevention, we propose strategies to minimise maternal and offspring exposure to potentially harmful variables and recommend protective measures during pregnancy and the postpartum period. This holistic view of early-life factors and microbiome signatures among mothers and their offspring will help frame our current understanding of their importance towards IBD pathogenesis and frame the roadmap for preventive strategies.

Biological therapy for inflammatory bowel disease: cyclical rather than lifelong treatment?

Inflammatory bowel disease (IBD) treatment was revolutionised with the arrival of biological therapy two decades ago. There are now multiple biologics and increasingly novel small molecules licensed for the treatment of IBD. Treatment guidelines highlight the need for effective control of inflammation and early escalation to advanced therapies to avoid long-term complications. Consequently, a large proportion of patients with IBD receive advanced therapies for a long time. Despite their beneficial risk-benefit profile, these treatments are not without risk of side effects, are costly to healthcare providers and pose a burden to the patient. It is, therefore, paramount to examine in which circumstances a temporary cessation of therapy can be attempted without undue clinical risk. Some patients may benefit from cyclical rather than continuous treatment. This review examines the risk of relapse after discontinuation of advanced therapies, how to identify patients at the lowest risk of relapse and the chance of recapturing response when flaring after discontinuation.

Determining the optimal treatment target in patients with ulcerative colitis: rationale, design, protocol and interim analysis for the randomised controlled VERDICT trial

INTRODUCTION

Symptoms, endoscopy and histology have been proposed as therapeutic targets in ulcerative colitis (UC). Observational studies suggest that the achievement of histologic remission may be associated with a lower risk of complications, compared with the achievement of endoscopic remission alone. The actiVE ulcerative colitis, a RanDomIsed Controlled Trial (VERDICT) aims to determine the optimal treatment target in patients with UC.

METHODS AND ANALYSIS

In this multicentre, prospective randomised study, 660 patients with moderate to severe UC (Mayo rectal bleeding subscore [RBS] ≥1; Mayo endoscopic score [MES] ≥2) are randomly assigned to three treatment targets: corticosteroid-free symptomatic remission (Mayo RBS=0) (group 1); corticosteroid-free endoscopic remission (MES ≤1) and symptomatic remission (group 2); or corticosteroid-free histologic remission (Geboes score <2B.0), endoscopic remission and symptomatic remission (group 3). Treatment is escalated using vedolizumab according to a treatment algorithm that is dependent on the patient's baseline UC therapy until the target is achieved at weeks 16, 32 or 48. The primary outcome, the time from target achievement to a UC-related complication, will be compared between groups 1 and 3 using a Cox proportional hazards model.

ETHICS AND DISSEMINATION

The study was approved by ethics committees at the country level or at individual sites as per individual country requirements. A full list of ethics committees is available on request. Study results will be disseminated in peer-reviewed journals and at scientific meetings.

TRIAL REGISTRATION NUMBER

EudraCT: 2019-002485-12; NCT04259138.

Controversies in the management of anti-TNF therapy in patients with Crohn's disease: a Delphi consensus

BACKGROUND

Despite research, there are still controversial areas in the management of Crohn's disease (CD).

OBJECTIVE

To establish practical recommendations on using anti-tumour necrosis factor (TNF) drugs in patients with moderate-to-severe CD.

METHODS

Clinical controversies in the management of CD using anti-TNF therapies were identified. A comprehensive literature review was performed, and a national survey was launched to examine current clinical practices when using anti-TNF therapies. Their results were discussed by expert gastroenterologists within a nominal group meeting, and a set of statements was proposed and tested in a Delphi process.

RESULTS

Qualitative study. The survey and Delphi process were sent to 244 CD-treating physicians (response rate: 58%). A total of 14 statements were generated. All but two achieved agreement. These statements cover: (1) use of first-line non-anti-TNF biological therapy; (2) role of HLA-DQA1*05 in daily practice; (3) attitudes in primary non-response and loss of response to anti-TNF therapy due to immunogenicity; (4) use of ustekinumab or vedolizumab if a change in action mechanism is warranted; (5) anti-TNF drug level monitoring; (6) combined therapy with an immunomodulator.

CONCLUSION

This document sought to pull together the best evidence, experts' opinions, and treating physicians' attitudes when using anti-TNF therapies in patients with CD.

JAK inhibitors for inflammatory bowel disease: recent advances

Inflammatory bowel disease (IBD) commonly requires immunosuppressive treatments to induce and maintain durable remission. Janus kinase inhibitors (JAKis) are a novel group of orally administered, small molecule drugs that work by attenuating multiple cytokine signalling pathways to mediate dysregulated immune responses involved in the pathogenesis of IBD. Tofacitinib, filgotinib and upadacitinib have demonstrated efficacy against placebo and are licensed for the treatment of moderate to severe ulcerative colitis; upadacitinib is the only JAKi also currently approved for the treatment of Crohn's disease. Safety concerns stratified by age have led to class-wide regulatory restrictions for JAKi use across all inflammatory diseases. It is important for gastroenterologists managing patients with IBD to be aware of the key pivotal trial outcomes, to identify appropriate patients in whom to commence a JAKi, and to understand the safety considerations and ways to mitigate these risks in the patients they treat. This review provides a contemporaneous overview of this emerging therapeutic class and provides a practical guide for healthcare practitioners for initiating and monitoring JAKi in IBD.

People with IBD evidence more microarousals during sleep architecture assessments

OBJECTIVE

Poor sleep is common in inflammatory bowel disease (IBD) and may be associated with overall worse disease outcomes. While the sleep/IBD literature is growing, the data are often self-reported. Further, much of the research using objective measures of sleep architecture, or the overall pattern of sleep depth, rely on single-night assessments, which can be of questionable validity.

DESIGN

Participants with IBD and healthy controls were recruited from Dartmouth-Hitchcock Medical Center as part of a two-phase clinical trial. Sleep architecture was assessed using three nights of in-home electroencephalographic monitoring and scored according to the American Academy of Sleep Medicine guidelines.

RESULTS

Our sample included 15 participants with IBD and 8 healthy controls. Participants with IBD were more psychiatrically complex, with more self-reported insomnia, anxiety and depression. Participants with IBD evidenced greater microarousals than healthy controls. In participants with IBD, microarousals were associated with lower insomnia and greater depression scores. Within IBD, participants with clinically significant insomnia evidenced trend towards lower sleep efficiency, while self-reported disease activity did not significantly impact findings.

CONCLUSIONS

The methodology of past research may have impacted findings, including the reliance on single-night assessments and limited generalisability. Future research that uses robust, multinight assessments of sleep architecture in large, diverse samples is clearly warranted, as is research exploring the impact of cognitive and behavioural factors on sleep architecture and arousal.

TRIAL REGISTRATION NUMBER

NCT04132024.

Chronic abdominal pain in inflammatory bowel disease: a practical guide

Pain is common in inflammatory bowel disease (IBD), yet many patients feel their pain is not addressed by healthcare professionals. Listening to a patient's concerns about pain, assessing symptoms and acknowledging the impact these have on daily life remain crucial steps in addressing pain in IBD. While acute pain may be effectively controlled by pain medication, chronic pain is more complex and often pharmacological therapies, particularly opioids, are ineffective. Low-dose tricyclic antidepressants and psychological approaches, including cognitive-behavioural therapy, have shown some promise in offering effective pain management while lifestyle changes such as a trial of low-fermentable oligosaccharides, disaccharides, monosaccharides and polyols diet in those with overlapping irritable bowel syndrome may also reduce pain. Patients benefit from a long-term, trusting relationship with their healthcare professional to allow a holistic approach combining pharmacological, psychological, lifestyle and dietary approaches to chronic pain. We present a practical review to facilitate management of chronic abdominal pain in IBD.

The first international Rome consensus conference on gut microbiota and faecal microbiota transplantation in inflammatory bowel disease

BACKGROUND

Several randomised clinical trials (RCTs) performing faecal microbiota transplantation (FMT) for the management of inflammatory bowel disease (IBD), particularly for ulcerative colitis, have recently been published, but with major variations in study design. These include differences in administered dose, route and frequency of delivery, type of placebo and evaluated endpoints. Although the overall outcomes appear to be promising, they are highly dependent on both donor and recipient factors.

OBJECTIVE

To develop concensus-based statements and recommendations for the evaluation, management and potential treatment of IBD using FMT in order to move towards standardised practices.

DESIGN

An international panel of experts convened several times to generate evidence-based guidelines by performing a deep evaluation of currently available and/or published data. Twenty-five experts in IBD, immunology and microbiology collaborated in different working groups to provide statements on the following key issues related to FMT in IBD: (A) pathogenesis and rationale, (B) donor selection and biobanking, (C) FMT practices and (D) consideration of future studies and perspectives. Statements were evaluated and voted on by all members using an electronic Delphi process, culminating in a plenary consensus conference and generation of proposed guidelines.

RESULTS AND CONCLUSIONS

Our group has provided specific statements and recommendations, based on best available evidence, with the end goal of providing guidance and general criteria required to promote FMT as a recognised strategy for the treatment of IBD.

Delphi consensus survey: the opinions of patients living with refractory ulcerative proctitis and the health care professionals who care for them

BACKGROUND

Refractory ulcerative proctitis presents a huge clinical challenge not only for the patients living with this chronic, progressive condition but also for the professionals who care for them. Currently, there is limited research and evidence-based guidance, resulting in many patients living with the symptomatic burden of disease and reduced quality of life. The aim of this study was to establish a consensus on the thoughts and opinions related to refractory proctitis disease burden and best practice for management.

METHODS

A three-round Delphi consensus survey was conducted among patients living with refractory proctitis and the healthcare experts with knowledge on this disease from the UK. A brainstorming stage involving a focus group where the participants came up with an initial list of statements was completed. Following this, there were three rounds of Delphi surveys in which the participants were asked to rank the importance of the statements and provide any additional comments or clarifications. Calculation of mean scores, analysis of comments and revisions were performed to produce a final list of statements.

RESULTS

In total, 14 statements were suggested by the focus group at the initial brainstorming stage. Following completion of three Delphi survey rounds, all 14 statements reached consensus following appropriate revision.

CONCLUSIONS

We established consensus on the thoughts and opinions related to refractory proctitis from both the experts who manage this disease and the patients living with it. This represents the first step towards developing clinical research data and ultimately the evidence needed for best practice management guidance of this condition.

Generalised urticaria and angioedema complicating switch back from subcutaneous to intravenous vedolizumab therapy

We report a unique case of a 34-year-old man with ulcerative colitis, previously in complete remission with intravenous vedolizumab monotherapy, who developed an urticarial injection-site reaction on switching to a subcutaneous preparation and thereafter experienced a new hypersensitivity reaction on switch back to intravenous vedolizumab, necessitating complete discontinuation from this drug. This case highlights the need for vigilance on switching back to intravenous preparations of vedolizumab, in response to injection-site reactions with a subcutaneous preparation, even if the intravenous preparation had been previously well tolerated by the patient.

Changes in health-related quality of life and associations with improvements in clinical efficacy: a Phase 2 study of mirikizumab in patients with ulcerative colitis

OBJECTIVE

Mirikizumab, a monoclonal antibody targeting the interleukin-23 p19 subunit, was effective in a Phase 2 study (NCT02589665) of moderately-to-severely active ulcerative colitis (UC). We studied mirikizumab's impact on health-related quality of life (HRQoL).

DESIGN

HRQoL was evaluated using the Inflammatory Bowel Disease Questionnaire (IBDQ) and 36-Item Short Form Health Survey (SF-36) Physical Component Score (PCS) and Mental Component Score (MCS). Mixed effects models for repeated measures compared score changes between mirikizumab and placebo groups. Additional analyses evaluated associations between HRQoL score changes and achievement of efficacy endpoints at weeks 12 and 52.

RESULTS

At week 12, IBDQ improved compared with placebo for all mirikizumab groups except mirikizumab 50 mg (50 mg, p=0.073; 200 mg, p<0.001; 600 mg, p<0.001). SF-36 PCS was significantly higher in all mirikizumab groups at week 12 (50 mg, p=0.011; 200 mg, p=0.022; 600 mg, p=0.002); MCS was significantly higher in mirikizumab 200 and 600 mg groups compared with placebo (50 mg, p=0.429; 200 mg, p=0.028; 600 mg, p<0.001). Achievement of clinical response and remission were associated with greater HRQoL improvements at week 12. Improvements in HRQoL scores were sustained through week 52. Of the clinical symptoms evaluated, reduction in rectal bleeding was associated with greater improvements in IBDQ and SF-36 scores.

CONCLUSION

Mirikizumab improved HRQoL in patients with moderately-to-severely active UC.

Autologous regulatory T-cell transfer in refractory ulcerative colitis with concomitant primary sclerosing cholangitis

OBJECTIVE

Ulcerative colitis (UC) is a chronic, debilitating immune-mediated disease driven by disturbed mucosal homeostasis, with an excess of intestinal effector T cells and an insufficient expansion of mucosal regulatory T cells (Tregs). We here report on the successful adoptive transfer of autologous, ex vivo expanded Tregs in a patient with refractory UC and associated primary sclerosing cholangitis (PSC), for which effective therapy is currently not available.

DESIGN

The patient received a single infusion of 1×10⁶ autologous, ex vivo expanded, polyclonal Tregs per kilogram of body weight, and the clinical, biochemical, endoscopic and histological responses were assessed 4 and 12 weeks after adoptive Treg transfer.

RESULTS

The patient showed clinical, biochemical, endoscopic and histological signs of response until week 12 after adoptive Treg transfer, which was associated with an enrichment of intestinal CD3⁺/FoxP3⁺ and CD3⁺/IL-10⁺ T cells and increased mucosal transforming growth factor beta and amphiregulin levels. Moreover, there was marked improvement of PSC with reduction of liver enzymes. This pronounced effect lasted for 4 weeks before values started to increase again.

CONCLUSION

These findings suggest that adoptive Treg therapy might be effective in refractory UC and might open new avenues for clinical trials in PSC.

TRIAL REGISTRATION NUMBER

NCT04691232.

Obesity among those newly diagnosed with Crohn's disease and ulcerative colitis compared with the general population

Objective

Obesity is a potentially modifiable risk factor for inflammatory bowel disease (IBD). We aimed to evaluate the body mass index (BMI) of those diagnosed with IBD early versus late in life in the context of age-adjusted background population.

Design/method

Patients with a new diagnosis of IBD from 2000 to 2021 were included. Early-onset IBD was classified as age <18 and late-onset IBD classified as age ≥65. Obesity was classified as BMI ≥30 kg/m2. Population data were obtained from community surveys.

Results

Included were 1573 patients (56.0%) with Crohn's disease (CD) and 1234 (44.0%) with ulcerative colitis (UC). Overall, the median BMI at IBD diagnosis was 20 kg/m2 (IQR 18-24) among those diagnosed at age <18 vs 26.9 kg/m2 (IQR 23.1-30.0) among those diagnosed at age ≥65 (rank-sum p<0.01). In all age groups, BMI was stable during the 1-year preceding IBD diagnosis. At age <18, 11.5% of the background population was obese compared with 3.8% of those with newly diagnosed CD (p<0.01) and 4.8% of those with newly diagnosed UC (p=0.05). At age ≥65, 23.6% of the population was obese compared with 24.3% of those with newly diagnosed CD (p=0.78) and 29.5% of those with newly diagnosed UC (p=0.01).

Conclusion

Patients with IBD diagnosed at age <18 were less likely to be obese compared with the age-adjusted background population whereas those diagnosed at age ≥65 were more likely to be obese. Future prospective studies should investigate obesity as a modifiable risk factor for late-life IBD.

Association between socioeconomic status and mucosal healing in Japanese patients with ulcerative colitis: a cross-sectional study

Objective

Socioeconomic status is a risk factor for worse outcomes in many diseases. However, evidence on the association between socioeconomic status and clinical outcome in patients with ulcerative colitis (UC) is limited. In the clinical setting, the therapeutic goal for UC is to achieve mucosal healing (MH). Thus, the aim of this study is to examine the association between socioeconomic status and MH in patients with UC.

Methods

The study population consisted of 298 patients with UC. Education status and household income were divided into three groups based on a self-administered questionnaire. MH and complete MH were defined as a Mayo endoscopic subscore of 0–1 and 0, respectively. The association of socioeconomic status with MH and complete MH was assessed by multivariate logistic regression analysis. Patients with UC were divided into a younger group (<51 years old) and an older group (≥51 years old) based on median age.

Results

The percentage of MH and complete MH was 62.4% and 25.2%, respectively. In all patients, socioeconomic status was not associated with MH and complete MH, respectively. In the older group, education but not household income was independently positively associated with MH and complete MH. In contrast, in the younger group, no association between socioeconomic status and MH and complete MH was found.

Conclusion

In older Japanese patients with UC, education status but not household income was independently positively associated with MH and complete MH.

Satisfaction with telemedicine-delivered inflammatory bowel disease care depends on disease activity, personality and economic factors

Objective

Patients with inflammatory bowel disease (IBD) traditionally receive follow-up care at face-to-face outpatient clinics. During the COVID-19 pandemic, gastroenterology societies recommended IBD clinics to be carried out remotely where possible using telephone or telemedicine-delivered virtual clinics. Previous studies have demonstrated patient satisfaction with virtual clinics but few studies have examined factors that impact satisfaction or assessed patient's personal perception of the virtual clinic experience.

Design/method

Patients who had their IBD clinic appointment changed from face-to-face to telephone virtual clinic completed a questionnaire relating to their clinical experience and preference for future care. Qualitative data were also collected and evaluated using content analysis to identify major themes associated with the patient experience.

Results

141 patients were included for analysis. The virtual clinic satisfaction questionnaire was found to be valid while patients expressed high-satisfaction levels with virtual clinics (median satisfaction score 18, range 0-20). Multivariate analysis identified open personality type (p=0.004), short disease duration (p=0.047) and higher cost to attend clinic (p=0.047) as predictors of high-satisfaction levels, with active disease (p=0.035) and an agreeable personality type (p=0.042) associated with low satisfaction levels. Content analysis of the qualitative data identified three major themes connected to virtual clinic convenience, lack of physical interaction and disease activity.

Conclusion

Patients expressed high levels of satisfaction with telemedicine-delivered IBD clinics, with most wishing to continue their use. Personality type should be recognised as an important variable affecting clinical satisfaction, in addition to socioeconomic and disease-related factors.

Decreased risk of treatment failure with vedolizumab and thiopurines combined compared with vedolizumab monotherapy in Crohn's disease

OBJECTIVE

While infliximab combined to thiopurines is more effective than infliximab monotherapy in patients with Crohn's disease (CD) and UC, the impact of adding thiopurines to vedolizumab remains controversial. We emulated two target trials comparing the effectiveness of combination therapy versus vedolizumab monotherapy in CD and UC.

DESIGN

Based on two US and the French nationwide healthcare databases, patients with CD and UC who initiated vedolizumab were identified. The study methodology, including confounding adjustment and outcome definitions, were previously validated in successful emulations of the SONIC and SUCCESS trials. Risk ratios for treatment failure based on hospitalisation or surgery related to disease activity, treatment switch, or prolonged corticosteroids use, were estimated after 1:1 propensity score (PS) matching.

RESULTS

Among a total of 10 299 vedolizumab users, 804 CD and 1088 UC pairs of combination therapy versus vedolizumab monotherapy users were PS matched. Treatment failure occurred at week 26 in 236 (29.3%) and 376 (34.3%) patients with CD and at week 16 in 236 (21.7%) and 263 (24.2%) patients with UC initiating combination therapy and vedolizumab monotherapy, respectively. The risk of treatment failure was decreased with combination therapy compared with vedolizumab monotherapy in CD (RR 0.85, 95% CI: 0.74 to 0.98) and to a lesser extent in UC (RR 0.90, 95% CI: 0.77 to 1.05). Findings were consistent across databases.

CONCLUSION

Using validated methodologies, combination therapy with vedolizumab and thiopurines was associated with lower treatment failure compared with vedolizumab monotherapy in CD but not UC across the USA and France.

Clinical procedures used to diagnose inflammatory bowel disease: real-world evidence from a Danish nationwide population-based study

Objective

Although clinical guidelines exist, the diagnostic work-up for diagnosing inflammatory bowel disease (IBD) is complex and varies in clinical practice. This study used real-life data to characterise the current diagnostic procedures used to establish IBD diagnoses in a Danish nationwide setting.

Design

Person-level data on patients diagnosed with IBD between 1 January 2014 and 30 June 2018 were linked between Danish health registers. Information on age, sex, registration of other gastrointestinal diseases, and diagnostic procedures (endoscopies, biopsies, and imaging) performed in relation to the first IBD hospital admission was analysed for the total study population and was stratified by IBD type, sex, and age.

Results

The majority of the 12 871 patients with IBD included underwent endoscopy (84%), had a biopsy taken (84%), and/or underwent imaging procedures (44%). In total, 7.5% of the population (6% for Crohn’s disease and 8% for ulcerative colitis) were diagnosed with IBD despite not undergoing any of these diagnostic procedures. Patients with Crohn’s disease underwent more procedures than patients with ulcerative colitis (94% vs 92%, p<0.001). Children underwent slightly fewer diagnostic procedures than adults (92% vs 93%, p=0.004). Slightly more men underwent at least one procedure than women (92% vs 94%, p<0.001).

Conclusion

For 7.5% of patients with IBD, this study did not detect any registrations of the recommended diagnostic procedures for establishing an IBD diagnosis. Further research is needed to examine whether these findings are mainly explained by limitations of the register data or also indicate shortcomings of the general approach to IBD.

Development and test-retest reliability of a new, self-report questionnaire assessing healthcare use and personal costs in people with inflammatory bowel disease: the Inflammatory Bowel Disease Resource Use Questionnaire (IBD-RUQ)

BACKGROUND AND AIMS

The increasing prevalence of inflammatory bowel disease (IBD) poses a substantial economic burden globally on health systems and societies. Validated instruments to collect data on healthcare and other service utilisation by patients with IBD are lacking. We developed a self-report patient questionnaire to capture key resource utilisation from health services, patient and societal perspectives.

METHODS

The IBD Resource Use Questionnaire (IBD-RUQ), developed by a multidisciplinary team, including patients, comprises 102 items across the six categories of outpatient visits, diagnostics, medication, hospitalisations, employment and out-of-pocket expenses over the past three months. The test-retest reliability of the IBD-RUQ was studied by administering it twice among patients with IBD with a 2-week time gap. The intraclass correlation coefficients and the average cost from the healthcare, societal and patient perspectives, between test and retest assessments, overall and by service category, were summarised.

RESULTS

The IBD-RUQ captures health service use, employment and out-of-pocket expenses. Of 55 patients who completed the first questionnaire, 48 completed the retest questionnaires and were included in the analyses. Test-retest reliability for categories of medications, diagnostics, specialist outpatient and inpatient services, and days off work due to IBD ranged from moderate to excellent; primary care visits showed more limited reliability. The annualised average self-reported health service, out-of-pocket and loss of productivity costs were £4844, £320 and £545 per patient, respectively.

CONCLUSIONS

The IBD-RUQ is a reliable and valid self-report measure of resource utilisation in adults with IBD and can be used to measure costs associated with IBD.

Microbial determinants of effective donors in faecal microbiota transplantation for UC

OBJECTIVE

Faecal microbiota transplantation (FMT) has variable efficacy in treating UC. Recently, oral lyophilised FMT was found to induce remission in patients with UC, with one donor having 100% efficacy compared with a second donor (36% efficacy). We characterised differences in the gut microbiota of these two donors with the aim of improving FMT donor selection.

DESIGN

Faecal samples from the two donors were collected over a period of 44 (donor 1) or 70 (donor 2) weeks. The microbiome and metabolome were profiled using shotgun metagenomics and untargeted metabolomics RESULTS: Gut microbiome long-term stability was highly evident in the effective donor. Donor microbiota species evenness was a robust feature associated with clinical efficacy across two clinical trials of FMT in UC, leading to increased donor species engraftment in patients. Alpha diversity and beta diversity of donor gut microbiotas significantly differed. 90 bacterial species and one archaeon were differentially abundant between donors, 44 of which were >0.1% in relative abundance. 17/44 species were enriched in the effective donor, 11 of which (64.7%) were assembled into high-quality genomes that were prevalent (≥75% samples) in that donor, and six showed evidence of engraftment in patients. Taxonomic differences between donors translated to substantial microbial functional differences that were validated using metabolomics.

CONCLUSION

Donor microbiota stability and species evenness were identified as novel metrics that were associated with therapeutic efficacy in UC, beyond individual microbial species or metabolites. These metrics may represent community resilience that translates to better engraftment in the host.

TRIAL REGISTRATION NUMBER

ACTRN12619000611123.

Appendectomy and risk for inflammatory bowel disease: effect of age and time post appendectomy - a cohort study

Background and objective

Appendectomy may modulate the risk of inflammatory bowel disease through an effect on the gut microbiota. This study investigated the associations between appendectomy and incidence of Crohn’s disease (CD) or ulcerative colitis (UC), with an emphasis on the influence of age and time post appendectomy.

Methods

This cohort study included 400 520 subjects born in Québec in 1970–1974 and followed until 2014. Administrative health data were used to ascertain appendectomy and cases of CD and UC. Cox proportional hazards models with time-dependent variables (appendectomy and time elapsed post appendectomy) allowed for the estimation of HRs and 95% CIs.

Results

A total of 2545 (0.6%) CD cases and 1134 (0.3%) UC cases were identified during follow-up. Appendectomy increased the risk of CD (HR=2.02; 95% CI: 1.66 to 2.44), especially when performed at 18–29 years of age. The risk of CD was increased in the first 2 years, and decreased significantly after ≥15 years post appendectomy. Appendectomy appeared to protect against UC (HR=0.39; 95% CI: 0.22 to 0.71). The risk of UC was not associated with age at appendectomy, but decreased with time elapsed post appendectomy (HR=0.21; 95% CI: 0.06 to 0.72, comparing ≥5 with 0–4 years after appendectomy).

Conclusions

The increased risk of CD related to appendectomy in young adults may result from detection bias, but physicians should have a low threshold for suspicion of CD in young symptomatic adults with a history of appendectomy. A strong protective effect of appendectomy against UC was observed after 5 years.

IBD therapeutics: what is in the pipeline?

Inflammatory bowel disease (IBD) is an idiopathic long-term relapsing and remitting disorder including ulcerative colitis and Crohn's disease. The aim of therapy is to induce and maintain remission. Anti-TNF therapies dramatically improved clinical outcomes but primary failure or secondary loss is a common problem as well as potential side effects potentially limiting efficacy and long-term use. The advent of new targeted agents with the potential for greater safety is welcomed in IBD and offers the potential for different agents as the disease becomes refractory or even combination therapies to maximise effectiveness without compromising safety in the future. More data are required to understand the best positioning in pathways and longer-term safety effects.

Ustekinumab for the treatment of moderate to severe ulcerative colitis: a multicentre UK cohort study

OBJECTIVE

Ustekinumab is an interleukin-12/interleukin-23 receptor antagonist licensed for the treatment of ulcerative colitis (UC). Clinical trial data were promising; however, real-world data are limited. We assessed the safety and effectiveness of ustekinumab in UC in a real-world setting.

DESIGN/METHOD

This was a multicentre, retrospective, observational cohort study between February 2020 and January 2022. Disease activity was assessed using the Simple Clinical Colitis Activity Index (SCCAI). Clinical remission was defined as a SCCAI≤2. The primary endpoints were rates of corticosteroid-free remission (CSFR) at week 16 and at week 26. Objective outcomes, including faecal calprotectin (FCAL), were also collected.

RESULTS

110 patients with UC (65% male; median age 40 (IQR range 29-59); 96% with prior biologic and/or tofacitinib exposure) had a median follow-up of 28 weeks (IQR 17-47). CSFR was 36% (18/50) at week 16% and 33% (13/39) at week 26, corresponding with a significant fall in SCCAI from 6 (IQR 4-8) at baseline to 3 (IQR 0-5) at week 26, p<0.001. By week 16, there was improvement of median FCAL measurements, which fell from a baseline of 610 µg/g (IQR 333-1100) to 102 µg/g (IQR 54-674) at week 16. At the end of follow-up, 15% (17/110) had discontinued treatment; 13 patients due to primary non-response or loss of response, and 1 patient for family planning. Treatment was discontinued in three patients due to adverse events.

CONCLUSION

In the largest real-world study to date, ustekinumab was effective with a reassuring safety profile in a refractory cohort of patients.

Are we addressing the top 10 research priorities in IBD?

BACKGROUND

Since publication of the top 10 research priorities in inflammatory bowel disease (IBD) based on the James Lind Alliance Priority Setting Partnership, the question remains whether this has influenced the IBD-research landscape. This study aimed to create an overview of the current distribution of research interests of trials in the UK.

METHODS

The ClinicalTrials.gov database and European Union Clinical Trials Register were screened for clinical trials set up from 9 August 2016 to 16 November 2019 in the UK involving adult patients with IBD.

RESULTS

Of 20 non-industry-sponsored studies, a quarter investigated treatment strategies considering efficacy, safety and cost-effectiveness (priority 1). Four evaluated the role of diet (priorities 3 and 7). Development/assessment of biomarkers for patient stratification (priority 2) and fatigue (priority 8) were subject of three studies. IBD-related pain and control of diarrhoea/incontinence were each subject of 2 studies (priorities 4 and 6). The effect of gut microbiota (priority 10) and optimal strategy for perianal Crohn's disease (priority 5) was the focus of 2 studies each. One study evaluated surgery for terminal ileal Crohn's disease (priority 9). Of 63 industry-sponsored studies, 59 focused on priority 1.

CONCLUSIONS

This study presents an impression of the breadth of the IBD-research landscape in the UK, in light of the top 10 research priorities published in 2016. Optimal treatment strategy has been the most studied research priority by academic and industry-sponsored trials. Fewer studies focused on patient-reported outcomes. It remains debatable to what extent the current research landscape adequately represents all stakeholders' viewpoints on needs for expanded knowledge in IBD, particularly the patients' perspective.

Vascular adhesion protein-1 is elevated in primary sclerosing cholangitis, is predictive of clinical outcome and facilitates recruitment of gut-tropic lymphocytes to liver in a substrate-dependent manner

OBJECTIVE

Primary sclerosing cholangitis (PSC) is the classical hepatobiliary manifestation of IBD. This clinical association is linked pathologically to the recruitment of mucosal T cells to the liver, via vascular adhesion protein (VAP)-1-dependent enzyme activity. Our aim was to examine the expression, function and enzymatic activation of the ectoenzyme VAP-1 in patients with PSC.

DESIGN

We examined VAP-1 expression in patients with PSC, correlated levels with clinical characteristics and determined the functional consequences of enzyme activation by specific enzyme substrates on hepatic endothelium.

RESULTS

The intrahepatic enzyme activity of VAP-1 was elevated in PSC versus immune-mediated disease controls and non-diseased liver (p<0.001). The adhesion of gut-tropic α4β7⁺lymphocytes to hepatic endothelial cells in vitro under flow was attenuated by 50% following administration of the VAP-1 inhibitor semicarbazide (p<0.01). Of a number of natural VAP-1 substrates tested, cysteamine-which can be secreted by inflamed colonic epithelium and gut bacteria-was the most efficient (yielded the highest enzymatic rate) and efficacious in its ability to induce expression of functional mucosal addressin cell adhesion molecule-1 on hepatic endothelium. In a prospectively evaluated patient cohort with PSC, elevated serum soluble (s)VAP-1 levels predicted poorer transplant-free survival for patients, independently (HR: 3.85, p=0.003) and additively (HR: 2.02, p=0.012) of the presence of liver cirrhosis.

CONCLUSIONS

VAP-1 expression is increased in PSC, facilitates adhesion of gut-tropic lymphocytes to liver endothelium in a substrate-dependent manner, and elevated levels of its circulating form predict clinical outcome in patients.

Practical guidance on the use of faecal calprotectin

Differentiation between inflammatory bowel disease (IBD) and functional gut disorders, and the determination of mucosal disease activity in established cases of IBD remain the cornerstones of disease diagnosis and management. Non-invasive, accurate biomarkers of gut inflammation are needed due to the variability of symptoms, the inaccuracies of currently available blood markers and the cost and invasive nature of endoscopy. Numerous biomarkers have been used and/or considered with some in current use. This article reviews the current evidence base around the indications for using biomarkers and their limitations, with a particular focus on faecal calprotectin.

Development of an index to define overall disease severity in IBD

BACKGROUND AND AIM

Disease activity for Crohn's disease (CD) and UC is typically defined based on symptoms at a moment in time, and ignores the long-term burden of disease. The aims of this study were to select the attributes determining overall disease severity, to rank the importance of and to score these individual attributes for both CD and UC.

METHODS

Using a modified Delphi panel, 14 members of the International Organization for the Study of Inflammatory Bowel Diseases (IOIBD) selected the most important attributes related to IBD. Eighteen IOIBD members then completed a statistical exercise (conjoint analysis) to create a relative ranking of these attributes. Adjusted utilities were developed by creating proportions for each level within an attribute.

RESULTS

For CD, 15.8% of overall disease severity was attributed to the presence of mucosal lesions, 10.9% to history of a fistula, 9.7% to history of abscess and 7.4% to history of intestinal resection. For UC, 18.1% of overall disease severity was attributed to mucosal lesions, followed by 14.0% for impact on daily activities, 11.2% C reactive protein and 10.1% for prior experience with biologics. Overall disease severity indices were created on a 100-point scale by applying each attribute's average importance to the adjusted utilities.

CONCLUSIONS

Based on specialist opinion, overall CD severity was associated more with intestinal damage, in contrast to overall UC disease severity, which was more dependent on symptoms and impact on daily life. Once validated, disease severity indices may provide a useful tool for consistent assessment of overall disease severity in patients with IBD.

Long-term outcome of patients with steroid-refractory acute severe UC treated with ciclosporin or infliximab

OBJECTIVE

Ciclosporin and infliximab have demonstrated short-term similar efficacy as second-line therapies in patients with acute severe UC (ASUC) refractory to intravenous steroids. The aim of this study was to assess long-term outcome of patients included in a randomised trial comparing ciclosporin and infliximab.

DESIGN

Between 2007 and 2010, 115 patients with steroid-refractory ASUC were randomised in 29 European centres to receive ciclosporin or infliximab in association with azathioprine. Patients were followed until death or last news up to January 2015. Colectomy-free survival rates at 1 and 5 years and changes in therapy were estimated through Kaplan-Meier method and compared between initial treatment groups through log-rank test.

RESULTS

After a median follow-up of 5.4 years, colectomy-free survival rates (95% CI) at 1 and 5 years were, respectively, 70.9% (59.2% to 82.6%) and 61.5% (48.7% to 74.2%) in patients who received ciclosporin and 69.1% (56.9% to 81.3%) and 65.1% (52.4% to 77.8%) in those who received infliximab (p=0.97). Cumulative incidence of first infliximab use at 1 and 5 years in patients initially treated with ciclosporin was, respectively, 45.7% (32.6% to 57.9%) and 57.1% (43.0% to 69.0%). Only four patients from the infliximab group were subsequently switched to ciclosporin. Three patients died during the follow-up, none directly related to UC or its treatment.

CONCLUSIONS

In this cohort of patients with steroid-refractory ASUC initially treated by ciclosporin or infliximab, long-term colectomy-free survival was independent from initial treatment. These long-term results further confirm a similar efficacy and good safety profiles of both drugs and do not favour one drug over the other.

TRIAL REGISTRATION NUMBER

EudraCT: 2006-005299-42; ClinicalTrials.gouv number: NCT00542152; post-results.

Effect of vedolizumab (anti-α4β7-integrin) therapy on histological healing and mucosal gene expression in patients with UC

OBJECTIVE

Lymphocyte recruitment to the inflamed gut is increased in UC. Inhibition of this cell trafficking by vedolizumab (VDZ) was successful in inducing and maintaining remission and in induction of endoscopic mucosal healing. There are no data on histological healing with VDZ. We studied histological changes following VDZ therapy and compared gene expression in patients with UC before and after therapy.

DESIGN

Forty-one patients with UC from GEMINI I and LTS were studied before and at three time points (weeks 6/12/52) following VDZ therapy. Colonic biopsies were scored using the Geboes index and correlated with Mayo endoscopic subscore. Gene expression was analysed using Affymetrix gene arrays.

RESULTS

Fifty-five per cent of patients achieving endoscopic healing (= Mayo endoscopic subscore 0-1) with VDZ at the studied time points also had histological healing (= Geboes grade 0-1). In most healers, some residual histological changes (eg, disturbed architecture and increased mononuclear cell infiltrate) were still observed, although this was less at week 52. VDZ restored expression of many inflammatory genes in patients with endoscopic healing only at week 52 and not before. In VDZ healers, the expression of many genes remained dysregulated at weeks 6/12/52 compared with controls.

CONCLUSIONS

VDZ induces histological healing in >50% of patients with endoscopic healing, with maximal effect at week 52. VDZ also restored, although incompletely, the colonic expression of many immune-related genes in patients with UC achieving endoscopic healing at week 52. However, persistent histological and gene dysregulations did remain even in healers, suggesting that maintenance therapy will be necessary to control the intestinal inflammation.

TRIAL REGISTRATION NUMBERS

NCT00783718 and NCT00790933; post-results.

Real-life chromoendoscopy for neoplasia detection and characterisation in long-standing IBD

OBJECTIVE

Outside clinical trials, the effectiveness of chromoendoscopy (CE) for long-standing IBD surveillance is controversial. We aimed to assess the effectiveness of CE for neoplasia detection and characterisation, in real-life.

DESIGN

From June 2012 to 2014, patients with IBD were prospectively included in a multicentre cohort study. Each colonic segment was evaluated with white light followed by 0.4% indigo carmine CE. Specific lesions' features were recorded. Optical diagnosis was assessed. Dysplasia detection rate between expert and non-expert endoscopists and learning curve were ascertained.

RESULTS

Ninety-four (15.7%) dysplastic (1 cancer, 5 high-grade dysplasia, 88 low-grade dysplasia) and 503 (84.3%) non-dysplastic lesions were detected in 350 patients (47% female; mean disease duration: 17 years). Colonoscopies were performed with standard definition (41.5%) or high definition (58.5%). Dysplasia miss rate with white light was 40/94 (57.4% incremental yield for CE). CE-incremental detection yield for dysplasia was comparable between standard definition and high definition (51.5% vs 52.3%, p=0.30). Dysplasia detection rate was comparable between expert and non-expert (18.5% vs 13.1%, p=0.20). No significant learning curve was observed (8.2% vs 14.2%, p=0.46). Sensitivity, specificity, and positive and negative predictive values for dysplasia optical diagnosis were 70%, 90%, 58% and 94%, respectively. Endoscopic characteristics predictive of dysplasia were: proximal location, loss of innominate lines, polypoid morphology and Kudo pit pattern III-V.

CONCLUSIONS

CE presents a high diagnostic yield for neoplasia detection, irrespectively of the technology and experience available in any centre. In vivo, CE optical diagnosis is highly accurate for ruling out dysplasia, especially in expert hands. Lesion characteristics can aid the endoscopist for in situ therapeutic decisions.

TRIAL REGISTRATION NUMBER

NCT02543762.

Can faecal calprotectin predict relapse in inflammatory bowel disease: a mini review

Crohn's disease and ulcerative colitis are chronic inflammatory disorders affecting the gastrointestinal tract. Faecal calprotectin is a protein complex of the S-100 family of calcium-binding proteins present in inflammatory cells that can be measured in stool samples, which act as a biomarker for bowel inflammation. Elevated faecal calprotectin has been shown to reflect the presence of ongoing mucosal inflammation, which improves with mucosal healing. The aim of this review was to evaluate the available evidence on the ability of faecal calprotectin to predict a relapse in inflammatory bowel disease. Multiple retrospective studies have shown that patients who relapse have significantly higher levels of calprotectin in their stool compared with non-relapsers, especially in ulcerative colitis. Elevated faecal calprotectin postoperatively in Crohn's disease was also shown to be indicative of a relapse. However, the association of a raised faecal calprotectin and relapse is not universal and may be explained by the different patterns of mucosal inflammatory activity that exist. In conclusion, we put forward our hypothesis that changes such as a rise in faecal calprotectin levels may be more predictive of a relapse than absolute values.

Alterations in the epithelial stem cell compartment could contribute to permanent changes in the mucosa of patients with ulcerative colitis

OBJECTIVE

UC is a chronic inflammatory disease of the colonic mucosa. Growing evidence supports a role for epithelial cell defects in driving pathology. Moreover, long-lasting changes in the epithelial barrier have been reported in quiescent UC. Our aim was to investigate whether epithelial cell defects could originate from changes in the epithelial compartment imprinted by the disease.

DESIGN

Epithelial organoid cultures (EpOCs) were expanded ex vivo from the intestinal crypts of non-IBD controls and patients with UC. EpOCs were induced to differentiate (d-EpOCs), and the total RNA was extracted for microarray and quantitative real-time PCR (qPCR) analyses. Whole intestinal samples were used to determine mRNA expression by qPCR, or protein localisation by immunostaining.

RESULTS

EpOCs from patients with UC maintained self-renewal potential and the capability to give rise to differentiated epithelial cell lineages comparable with control EpOCs. Nonetheless, a group of genes was differentially regulated in the EpOCs and d-EpOCs of patients with UC, including genes associated with antimicrobial defence (ie, LYZ, PLA2G2A), with secretory (ie, ZG16, CLCA1) and absorptive (ie, AQP8, MUC12) functions, and with a gastric phenotype (ie, ANXA10, CLDN18 and LYZ). A high rate of concordance was found in the expression profiles of the organoid cultures and whole colonic tissues from patients with UC.

CONCLUSIONS

Permanent changes in the colonic epithelium of patients with UC could be promoted by alterations imprinted in the stem cell compartment. These changes may contribute to perpetuation of the disease.

Discrepancies between patient-reported outcomes, and endoscopic and histological appearance in UC

OBJECTIVE

Both endoscopy and histology may be included in the definition of mucosal healing in UC. This study aimed to establish the association between patient-reported outcomes, specifically symptom measures, and the presence of inflammation as measured by endoscopy and histology in UC.

DESIGN

Using patient data from an observational multicentre study of UC (n=103), rectal bleeding (RB) and stool frequency (SF) symptom subscores of the Mayo Clinic Score (MCS) were compared with the endoscopic subscore (MCSe) and histology. Faecal calprotectin and biopsy cytokine expression were also evaluated.

RESULTS

When identifying UC patients with inactive disease, RB scores were superior to SF scores and the combination (sensitivity/specificity: MCSe=0/1, RB 77%/81%, SF 62%/95%, RB+SF 54%/95%; MCSe=0, RB 87%/66%, SF 76%/83%, RB+SF 68%/86%). Across different definitions of mucosal healing (MCSe≤1; 0; or 0 plus inactive histology), a larger subset of patients reported increased SF (39%, 25% and 27%, respectively) compared with RB (24%, 13% and 10%). Faecal calprotectin and inflammatory cytokine expression were higher in patients with active disease compared with patients with mucosal healing, but there were no differences between patients using increasingly stringent definitions of mucosal healing.

CONCLUSIONS

Endoscopically inactive disease is associated with absence of RB but not with complete normalisation of SF. Achieving histological remission did not improve symptomatic relief. In addition, in these patients, higher inflammatory biomarker levels were not observed. These data suggest that non-inflammatory changes, such as bowel damage, may contribute to SF in UC.

Ulcerative proctitis is a frequent location of paediatric-onset UC and not a minor disease: a population-based study

OBJECTIVE

Natural history of paediatric-onset ulcerative proctitis (UP) is poorly described. Our aim was to describe the phenotype and disease course of incident UP in a population-based study of paediatric-onset UC.

PATIENTS AND METHODS

All patients with UC diagnosed <17 years from 1988 to 2004, and followed during >2 years have been extracted from a population-based registry. UC location was defined according to the Paris classification. Cumulative risks for use of immunosuppressants (IS), anti-tumour necrosis factor alpha (TNF-α) therapy, colonic extension and colectomy were described using Kaplan-Meier method. Risk factors for colonic extension were assessed using Cox proportional hazards models.

RESULTS

158 patients with paediatric-onset UC (91 females) with a median age at diagnosis of 14.5 years (Q1: 11.4-Q3: 16.1) have been identified and followed during a median of 11.4 years (8.2-15.8). Among them, 25% had UP (E1) at diagnosis and 49% of them presented a colonic extension at maximal follow-up. In these children, the cumulative risk for colonic extension was 10% at 1 year, 45% at 5 years and 52% at 10 years. No parameter at diagnosis was associated with colonic extension in the UP (E1 group). IS use was significantly lower in patients with UP than in those with E2, E3 or E4 location (p=0.049). For the UP cohort, the cumulative risk for colectomy was 3% at 1 year, 10% at 5 years, 13% at 10 years and 13% at 15 years. Risks for colonic extension, treatment with anti-TNF-α and colectomy did not differ between the E1 group and the E2-E3-E4 group.

CONCLUSIONS

UP is frequent in paediatric-onset UC and should not be considered as a minor disease. Compared with more extensive UC locations, risks for colonic extension, anti-TNF-α therapy and colectomy were similar in UP, whereas the risk for use of IM was lower.

Assays for measurement of TNF antagonists in practice

Tumour necrosis factor (TNF) antagonist drug exposure is correlated with clinical, endoscopic and pathophysiological outcomes during induction and maintenance therapy. Measuring drug concentrations is therefore a useful tool when treating to target and optimising therapy. One of the main factors leading to suboptimal drug exposure is the formation of antidrug antibodies (ADAs), due to an immunogenic reaction of the immune system towards the non-self protein. The development of ADA does pose important concerns for drug efficacy and for safety as ADAs have been associated with acute infusion reactions, hypersensitivity reactions and serum sickness. Various assays exist to measure serum drug and ADA concentrations, either offered as a service in a specialised laboratory or commercially available as a kit. It is unclear how the performance of these assays relates to each other, until recently various comparative studies were carried out. The majority of these studies show that indeed a good correlation exists between the assays that measure drug, but that absolute concentrations can differ across tests. This is particularly relevant in clinical practice when a specific threshold or drug concentration range is targeted. For ADA assays, drug sensitivity or the ability of the assay to measure ADA in the presence of drug remains an important issue, especially for drugs with a higher dosing frequency. In addition, standardisation across ADA assays is difficult, making it hard to compare quantitative or semiquantitative (low/medium/high) results across assays and across studies.

Implementing a self-management strategy in inflammatory bowel disease (IBD): patient perceptions, clinical outcomes and the impact on service

INTRODUCTION

Patient self-management and its service integration is not a new concept but it may be a key component in the long-term sustainability of inflammatory bowel disease (IBD) service provision, when considering growing disease prevalence and limited resources.

METHODS

The IBD team at the Royal Alexandra and Vale of Leven Hospitals in the Clyde Valley region developed a self-management tool, called the 'flare card'. Patients were asked to complete a questionnaire which reflected their opinion on its viability as a self-management intervention. In addition, its utility in terms of service use over a 10-month period in 2016 was compared with a similar cohort of patients over 10 months in 2015.

RESULTS

Patients overall felt that the 'flare card' was a viable self-management tool. Positive feedback identified that the intervention could help them aid control over their IBD, improve medication adherence, reduce symptoms and reflected a feeling of patient-centred IBD care. The comparison between 2015 and 2016 service use revealed a significant reduction in IBD and non-IBD service usage, Steroid prescribing and unscheduled IBD care in the flare card supported cohort.

CONCLUSIONS

IBD services must continue to adapt to changes within the National Health Service bearing in mind long-term sustainability and continued care provision. The 'flare card' goes further in an attempt to optimise Crohn's disease and ulcerative colitis management by harmonising clinician evaluation and patient's self-initiation of therapy and investigation.