Risk factors for malignancy and serious infection in patients with inflammatory bowel disease: a retrospective analysis

BACKGROUND

Patients with inflammatory bowel disease (IBD) are at increased risk of malignancy and infection compared to the general population.

AIMS

We aim to identify risk factors for malignancy or serious infection in our IBD cohort.

METHODS

Patients with IBD from a single tertiary referral centre were included. Demographic and clinical details, including immunosuppressant exposure, were collected and medical records retrospectively screened for adverse events, including malignancy or infection requiring hospitalisation. Logistic regression was used to evaluate risk factors for adverse events.

RESULTS

Five hundred and forty-nine patients with IBD (340 Crohn disease (CD) and 209 ulcerative colitis (UC)) were studied. Forty-eight malignancies, including 39 (81.3%) non-melanoma skin cancers, 3 (6.3%) haematologic malignancies and 6 (15.4%) solid-organ malignancies, were identified, and 92 cases of serious infection were detected. IBD duration (odds ratio (OR) = 1.08; 95% confidence interval (CI) = 1.03-1.13) and ileocolonic CD (OR = 4.96; 95% CI = 1.13-21.71) were associated with increased odds of overall cancer. Compared with patients not previously exposed to the given class of immunosuppression assessed, the development of overall malignancy was not higher with thiopurine exposure (OR = 1.00; 95% CI = 0.50-2.24) or anti-tumour necrosis factor-alpha (TNF-α) exposure (OR = 0.78; 95% CI = 0.37-1.64). Similarly, compared with patients not exposed, infection risk was not affected by thiopurine (OR = 0.74; 95% CI = 0.46-1.20) or anti-TNF exposure (OR = 0.60; 95% CI = 0.38-0.95).

CONCLUSIONS

Factors including ileocolonic CD and increasing IBD duration were associated with higher malignancy risk in this cohort. Compared with non-exposure, patients exposed to thiopurines were not at increased risk of malignancy or serious infection. Similarly, patients exposed to anti-TNF treatment did not experience increased rates of malignancy or serious infection compared to patients not exposed to this treatment.

Thiopurine metabolite shunting in late pregnancy increases the risk of intrahepatic cholestasis of pregnancy in women with inflammatory bowel disease, and can be managed with split-dosing

BACKGROUND AND AIMS

The risk of intrahepatic cholestasis of pregnancy (ICP) is increased in thiopurine exposed pregnancies. Thiopurine 'shunting', with a 6-methylmecrcaptopurine (MMP) to 6-thioguanine (TGN) ratio of >11, progresses over pregnancy, and may promote ICP development. We aimed to explore the association between thiopurine exposure and ICP, including the hypothesized impact of thiopurine shunting, and identify risk minimization strategies.

METHODS

This prospective multi-centre cohort study compared thiopurine and biologic monotherapy exposed pregnant participants. Disease activity and obstetric outcome data, thiopurine metabolites, bile acids and transaminases were obtained preconception, in each trimester, at delivery, and post-partum. Thiopurine dose management was at the discretion of the treating physician.

RESULTS

131 thiopurine and 147 biologic monotherapy exposed pregnancies were included. MMP/TGN ratio increased from preconception to third trimester (p<0.01), with approximately 25% of participants shunting in pregnancy. Second trimester split-dosing led to a decrease in the median MMP/TGN ratio from 18 (IQR 6-57) to 3 (IQR 2-3.5) at delivery (p=0.04). The risk of ICP was increased in thiopurine exposed pregnancies (6.7% (7/105) vs 0% (0/112), p<0.001), with all ICP cases occurring in the setting of antenatal thiopurine shunting. Thiopurine dose increases (RR 8.10 [95% CI 1.88-34.85] p=0.005) and shunting in third trimester (6.20 [1.21-30.73] p=0.028) and at delivery (14.18 [1.62-123.9] p=0.016) were associated with an increased risk of ICP.

CONCLUSIONS

Thiopurine exposure is associated with an increased risk of ICP, particularly following dose increases antenatally and with shunting in late pregnancy. The latter may be effectively managed with split dosing, although further studies are warranted.

Thrombocytosis and Transaminitis in Infants Born to Women With Inflammatory Bowel Disease Is Associated With Exposure to Maternal Inflammation In Utero

BACKGROUND

Despite reassuring clinical safety data, thrombocytosis, anemia, lymphopenia, and liver function derangements have been observed in infants born to women with inflammatory bowel disease (IBD) treated with thiopurines and biologics. We aimed to define the prevalence, course, associations, and clinical impact of hematological and biochemical abnormalities in such infants.

METHODS

This multicenter prospective cohort study assessed clinical, hematologic, and biochemical outcomes of infants exposed to thiopurines or biologics in utero for management of maternal IBD. Liver transaminases, full blood examination, and infant thiopurine metabolites (where exposed) were taken at delivery and 6 weeks of age. Abnormal results were repeated until normalization. Infants were followed clinically by a pediatric gastroenterologist up to 2 years of age.

RESULTS

A total of 130 infants were included. Thrombocytosis and elevated alanine transaminase (ALT) were seen in over half of infants up to 6 months of age with no significant clinical impact. Elevated ALT was associated with increasing maternal C-reactive protein in second trimester, while thrombocytosis was associated with increasing maternal C-reactive protein and fecal calprotectin in third trimester. Preceding infection and vaccination were associated with an increased risk of elevated alkaline phosphatase at 3 months. In those exposed to thiopurines, increasing maternal 6-methylmercaptopurine at delivery was associated with increased ALT to 6 months.

CONCLUSIONS

Infants born to women with IBD commonly developed thrombocytosis, elevated alkaline phosphatase, and elevated ALT. These findings were associated with exposure to maternal inflammation, elevated 6-methylmercaptopurine at delivery, and infant vaccinations and infections, and had minimal clinical consequence.

Thermo-optic VO2-based silicon waveguide mid-infrared router with asymmetric activation thresholds and large bi-stability: errata

The authors report an error in the phrasing and citation of the reference to simulation model input data in [Opt. Express31(14), 23260202310.1364/OE.493895]. The original phrasing misplaced "heat capacity" after the in-text citation, where the intended phrase was "electrical conductivity," and heat capacity was intended to be cited with thermal conductivity as external measured data. In the reference itself, the source cited for thermal conductivity and heat capacity was errantly cited as H. Kizuka, et al., Jpn. J. Appl. Phys.54, 053201 (2015)10.7567/JJAP.54.053201. The JJAP paper shows data for both thermal properties of VO2; however, the data utilized for our model input parameters are found in [J. Miranda, et al., Phys. Rev. B 98, 075144 (2018)], including heat capacity data reproduced therein from [T. Kawakubo and T. Nakagawa, J. Phys. Soc. Jap. 19, 4 (1964)]. There are no effects on the simulated data nor conclusions of this article due to the error.

Clinical outcomes amongst elderly patients with inflammatory bowel disease

BACKGROUNDS AND AIMS

Inflammatory bowel disease (IBD) affects a growing cohort of elderly patients. Our aim was to compare the quality of care received by elderly patients with IBD with a nonelderly adult IBD population using clinical markers including steroid-free clinical remission.

METHOD

Retrospective audit of all consecutive patients attending a specialist IBD centre over a 1-year period aged >60 (elderly cohort [EC]) and 50 consecutive patients aged 30-45 years (control cohort [CC]). A follow-up survey was completed assessing current symptoms and perceptions of care.

RESULTS

One hundred thirty-nine patients were evaluated (89 EC, 50 CC). Steroid-free clinical remission was observed less commonly in the EC (58, 64%) compared with the CC (40, 80%) (P < 0.05). Biologics such as infliximab (15% EC vs 36% CC; P < 0.01) and adalimumab (14% EC vs 30% CC; P = 0.02) were used less frequently in the EC, whilst vedolizumab (6% EC vs 6% CC; P = 1) and ustekinumab (3% EC vs 2% CC; P = 1) were used at a similar frequency. Patients in the EC were less likely to have specialist IBD nursing contact (P < 0.01), smoking screening (P < 0.011) or influenza vaccinations (P < 0.006). IBD nurse contact was associated with significantly greater provision of the preventative care measures.

CONCLUSION

Elderly patients with IBD were less likely to experience steroid-free clinical remission or be prescribed biologics. Elderly patients were less likely to receive education with respect to preventative medicine. The models of care for the elderly need re-evaluation and greater incorporation with the multidisciplinary IBD team.

Outcomes of a Comprehensive Specialist Inflammatory Bowel Disease Nursing Service

BACKGROUND

Inflammatory bowel disease (IBD) is best managed by a multidisciplinary team within a dedicated IBD service. IBD nurses play an important role within this team. We aimed to evaluate the contribution of our comprehensive outpatient IBD nursing service on patient outcomes, quality of care, and healthcare costs.

METHODS

We performed a retrospective review of all IBD nurse encounters with patients over a 12-month period from October 2020 to September 2021 at a tertiary IBD referral center. Each nurse encounter was classified with respect to its clinical context, activities, and outcomes. Descriptive statistics were used to characterize these encounters and an economic analysis was performed to estimate the cost savings to the hospital.

RESULTS

A total of 2537 nurse encounters occurred with 682 patients; 41% of encounters were nurse-initiated contacts with patients and 34% were patient-initiated contacts with the nurse helpline (26% via email, 8% via telephone). Most encounters involved clinical assessments (66%), providing education, counseling or updates (47%), and reviewing investigation results (38%). A gastroenterologist was consulted for advice in 35% of contacts. An estimated 29 emergency department visits, 1925 outpatient clinic visits, and 137 general practitioner visits were avoided. After deducting costs incurred, a net estimated annual saving of up to AUD $570 838 was achieved. Nurses commonly facilitated faster access to investigations (29%), education provision (28%), delivery of biologic services (25%), and medication changes (19%).

CONCLUSIONS

A comprehensive IBD nursing service is associated with improved patient outcomes and quality of care, and reduced healthcare costs. This study supports the expanding role of IBD nurses in a modern multidisciplinary IBD service and the need for greater funding and integration of IBD nurses into IBD services.

Thermo-optic VO2-based silicon waveguide mid-infrared router with asymmetric activation thresholds and large bi-stability

We report a novel four-port optical router that exploits non-linear properties of vanadium dioxide (VO₂) phase-change material to achieve asymmetrical power threshold response with power limiting capability. The scope of this study lies within the concept, modeling, and simulation of the device, with practical considerations in mind for future experimental devices. The waveguide structure, designed to operate at the wavelength of 5.0 µm, is composed of a silicon core with air and silicon dioxide forming the cladding layers. Two ring resonators are employed to couple two straight waveguides, thus four individual ports. One of the ring resonators has a 100-nm-thick VO₂ layer responsible for non-linear behavior of the device. The router achieves 56.5 and 64.5 dB of power limiting at the forward and reverse operating modes, respectively. Total transmission in the inactivated mode is 75%. Bi-stability and latching behavior are demonstrated and discussed.

Relationship Between Serum Ustekinumab Trough Concentration and Clinical and Biochemical Disease Activity: A Real-World Study in Adult Patients with Crohn's Disease

BACKGROUND AND OBJECTIVES

The role of therapeutic drug monitoring for ustekinumab in the treatment of Crohn's disease has not been defined. This study aimed to explore the relationship of serum ustekinumab trough concentration (UTC) with clinical and biochemical disease outcomes in a real-world setting.

METHODS

We performed a retrospective analysis of Crohn's disease patients treated at a single tertiary centre. Ustekinumab was given as a single intravenous induction dose, followed by maintenance subcutaneous injections every 4 to 8 weeks. Rates of clinical remission (Harvey-Bradshaw Index ≤ 4), biochemical remission (C-reactive protein < 5 mg/l and faecal calprotectin < 150 μg/g) and complete remission were assessed at baseline and at the time of UTC testing during maintenance therapy. The association between baseline variables and UTC was tested using linear regression. We also performed an external validation analysis of UTC cut-offs established in four previously published studies.

RESULTS

This study included 43 patients. Compared to 8-weekly dosing, a 2.49- and 2.65-fold increase in UTC was associated with 6-weekly and 4-weekly dosing respectively. However, there was no significant difference in clinical, biochemical or complete remission among the dosing groups. An external validation of previously published optimal UTC cut-offs found low predictive value for our patient population.

CONCLUSIONS

In this study, dosing interval was the only determinant significantly associated with a higher UTC for patients on maintenance ustekinumab therapy. While a higher UTC may be achieved with dose escalation, it was not associated with improved rates of clinical or biochemical response in our cohort.

Interventions to Improve Adherence to Preventive Care in Inflammatory Bowel Disease: A Systematic Review

BACKGROUND

Preventive health measures reduce treatment and disease-related complications including infections, osteoporosis, and malignancies in patients with inflammatory bowel disease (IBD). Although guidelines and quality measures for IBD care highlight the importance of preventive care, their uptake remains variable. This systematic review evaluates interventions aimed at improving the rates of provision and uptake of preventive health measures, including vaccinations, bone density assessment, skin cancer screening, cervical cancer screening, and smoking cessation counseling.

METHODS

We searched PubMed, MEDLINE, EMBASE, and CENTRAL for full text articles published until March 2021. Studies were included if they evaluated interventions to improve the provision or uptake of 1 or more preventive health measures in adult IBD patients and if they reported pre- and postintervention outcomes.

RESULTS

In all, 4655 studies were screened, and a total of 17 studies were included, including 1 randomized controlled trial, 1 cluster-controlled trial, and 15 prospective interventional studies. A variety of interventions were effective in improving the rates of adherence to preventive health measures. The most common interventions targeted gastroenterologists, including education, electronic medical records tools, and audit feedback. Other interventions targeted patients, such as education, questionnaires, and offering vaccine administration at clinic visits. Few interventions involved IBD nurses or primary care physicians.

CONCLUSIONS

A range of interventions-targeted at gastroenterologists, patients, or both-were effective in improving the provision and uptake of preventive care. Future studies should involve randomized controlled trials evaluating multifaceted interventions that target barriers to adherence and involve IBD nurses and primary care physicians.

Isolated esophageal IgG4-related disease presenting with progressive dysphagia and weight loss in a middle-aged man

Immunoglobulin G4-related disease (IgG4-RD) is an increasingly recognized immune-mediated condition that results in inflammation, stricturing and mass formation. It causes a wide spectrum of disease and clinical presentations depending on the organ system involved. Isolated esophageal IgG4-RD is rare and diagnosis can be difficult. It is highly responsive to corticosteroids, and early identification and instigation of management is key.We describe the case of a 47-year-old man who presented with a food bolus obstruction on a background of progressive dysphagia and weight loss. Imaging and gastroscopy demonstrated diffuse esophageal thickening with a benign appearing stricture. Following non-specific histologic findings on biopsy and a non-diagnostic endoscopic ultrasound guided fine needle aspiration, he underwent video-assisted thoracoscopic surgery with esophageal core biopsy. This confirmed the diagnosis of IgG4-RD. Initial treatment was with corticosteroids. However, due to recurrence of symptoms upon weaning of corticosteroids, azathioprine maintenance therapy was instituted. Azathioprine has previously been used in systemic cases of IgG4-RD but has not been reported for isolated esophageal disease.This case highlights the difficulties in the diagnosis and treatment of esophageal IgG4-RD and the need to consider it as a differential diagnosis when histology reveals esophagitis with lymphoplasmacytic infiltration.

Intensive drug therapy versus standard drug therapy for symptomatic intestinal Crohn's disease strictures (STRIDENT): an open-label, single-centre, randomised controlled trial

BACKGROUND

Strictures are the most common structural complication of Crohn's disease. Surgery and endoscopic balloon dilation are the main treatments; drug therapy has been considered contraindicated. Given that most strictures have an inflammatory component, we aimed to find out whether strictures are responsive to drug treatment and whether intensive drug therapy is more effective than standard drug therapy.

METHODS

This open-label, single-centre, randomised controlled trial was performed in one specialist inflammatory bowel disease centre in Australia. Patients aged 18 years or older with Crohn's disease were included. Eligible patients had a de novo or postoperative anastomotic intestinal stricture on MRI or ileocolonoscopy, symptoms consistent with chronic or subacute intestinal obstruction (postprandial abdominal pain in the presence of a confirmed stricture), and evidence of active intestinal inflammation. Patients were randomly assigned (2:1) to receive intensive high-dose adalimumab (160 mg adalimumab once per week for 4 weeks followed by 40 mg every 2 weeks, with escalation of dose at 4 months and 8 months if assessment of disease activity indicated active inflammation) plus thiopurine (initial dose of azathioprine 2·5 mg/kg or mercaptopurine 1·5 mg/kg, with dose adjustment based on thiopurine metabolite testing) or standard adalimumab monotherapy (160 mg at week 0, 80 mg at week 2, then 40 mg every 2 weeks) using stratified fixed block randomisation. Stratification factors were stricture dilation at study baseline colonoscopy and current biologic drug use. The primary endpoint was improvement (decrease) in the 14-day obstructive symptom score at 12 months by one or more points compared with baseline. This trial is registered with ClinicalTrials.gov, NCT03220841, and is completed.

FINDINGS

Between Sept 10, 2017, and Sept 6, 2019, 123 patients were screened and 77 randomly assigned to intensive adalimumab plus thiopurine treatment (n=52) or standard adalimumab treatment (n=25). At 12 months, improvement in obstructive symptom score was noted in 41 (79%) of 52 patients in the intensive treatment group and 16 (64%) of 25 in the standard treatment group (odds ratio [OR] 2·10 [95% CI 0·73-6·01]; p=0·17). Treatment failure occurred in five (10%) patients in the intensive treatment group versus seven (28%) in the standard treatment group (OR 0·27 [95% CI 0·08-0·97]; p=0·045); four patients in each group required stricture surgery (0·44 [0·10-1·92]; p=0·27). Crohn's Disease Activity Index was less than 150 in 36 (69%) patients in the intensive treatment group versus 15 (60%) in the standard treatment group (1·50 [0·56-4·05]; p=0·42). MRI at 12 months showed improvement using the stricture MaRIA score (≥25%) in 31 (61%) of 51 versus seven (28%) of 25 patients (3·99 [1·41-11·26]; p=0·0091). MRI complete stricture resolution was seen in ten (20%) versus four (16%) patients (1·28 [0·36 to 4·57]; p=0·70). Intestinal ultrasound at 12 months showed improvement (>25%) in bowel wall thickness in 22 (51%) of 43 versus seven (33%) of 21 patients (2·10 [0·71 to 6·21]; p=0·18). Faecal calprotectin normalised in 32 (62%) versus 11 (44%) patients (2·04 [0·77-5·36]; p=0·15). Normalisation of CRP was seen in 32 (62%) versus 11 (44%) patients (2·04 [0·77-5·36]; p=0·15). Eight (15%) patients in the intensive treatment group and four (16%) in the standard treatment group reported serious adverse events. No deaths occurred during the study.

INTERPRETATION

Crohn's disease strictures are responsive to drug treatment. Most patients had improved symptoms and stricture morphology. Treat-to-target therapy intensification resulted in less treatment failure, a reduction in stricture-associated inflammation, and greater improvement in stricture morphology, although these differences were not significantly different from standard therapy.

FUNDING

Australian National Health and Medical Research Council, Gastroenterological Society of Australia Ferring IBD Clinician Establishment Award, Australasian Gastro Intestinal Research Foundation, AbbVie, and the Spotlight Foundation.

Systematic review: efficacy of escalated maintenance anti-tumour necrosis factor therapy in Crohn's disease

BACKGROUND

Loss of response to anti-TNF agents is a common clinical problem. Dose escalation may be effective for reestablishing clinical response in Crohn's disease (CD).

AIMS

To perform a systematic review assessing the efficacy of escalated maintenance anti-TNF therapy in CD.

METHODS

EMBASE, MEDLINE, Web of Science, and CENTRAL databases were searched for English language publications through to April 25, 2021. Full-text articles evaluating escalated maintenance treatment (infliximab or adalimumab) in adult CD patients were included.

RESULTS

A total of 4733 records were identified, and 68 articles met eligibility criteria. Rates of clinical response (33%-100%) and remission (15%-83%) after empiric dose escalation for loss of response to standard anti-TNF therapy were high but varied across studies. Dose intensification strategies (doubling the dose versus shortening the therapeutic interval) were similarly efficacious. Dose-escalated patients tended to have higher serum drug levels compared to those on standard dosing. An exposure-response relationship following dose escalation was found in a number of observational studies. Randomised controlled trials comparing therapeutic drug monitoring (TDM) to empiric treatment intensification have failed to reach their primary end-points. Strategies including Bayesian dashboard-dosing and early treatment escalation targeting biomarker normalisation were found to be associated with improved long-term outcomes.

CONCLUSIONS

Empiric escalation of maintenance anti-TNF therapy can recapture clinical response in a majority of patients with secondary loss of response to standard maintenance doses. Proactive optimisation of maintenance dosing might prolong time to loss of response in some patients.

Telehealth model of care for outpatient inflammatory bowel disease care in the setting of the COVID-19 pandemic

Background

Advances in inflammatory bowel disease (IBD) monitoring, greater number of available treatments and a shift towards tight disease control, IBD care has become more dynamic with regular follow ups.

Aims

We assessed the impacts of the COVID‐19 pandemic on outpatient IBD patient care at a tertiary centre in Melbourne. More specifically, we assessed patient satisfaction with a telehealth model of care, failure to attend rates at IBD clinics and work absenteeism prior to and during the pandemic.

Methods

We conducted a retrospective, qualitative analysis to assess our aims through an online survey. We invited patients who attended an IBD outpatient clinic from April to June 2020 to participate. This study was conducted at a single, tertiary referral hospital in Melbourne. The key data points that we analysed were patient satisfaction with a telehealth model of care and the effect of telehealth clinics on work absenteeism.

Results

One hundred and nineteen (88.1%) patients were ‘satisfied’ or ‘very satisfied’ with the care received in the telehealth clinic. Eighty‐four (60.4%) patients reported needing to take time off work to attend a face‐to‐face appointment, compared to 29 (20.9%) patients who needed to take time off work to attend telehealth appointments (P < 0.001). Clinic non‐attendance rates were similar prior to and during the pandemic with rates of 11.4% and 10.4% respectively (P = 0.840).

Conclusions

Patients report high levels of satisfaction with a telehealth model of care during the COVID‐19 pandemic, with clinic attendance rates not being affected. Telehealth appointments significantly reduced work absenteeism when compared to traditional face‐to‐face clinics.

Long-term outcomes of perianal fistulizing Crohn's disease in the biologic era

Background and Aim

While the advent of biologic therapy has led to improved outcomes in perianal fistulizing Crohn's disease (pfCD), loss of response is common. Previous studies suggest that patients who achieve radiological healing (with healing of underlying tracts on magnetic resonance imaging [MRI]) have a longer duration of response. The aim of this study was to characterize MRI outcomes of pfCD at a specialist inflammatory bowel disease (IBD) unit and compare the long-term clinical outcomes between patients achieving MRI and clinical healing.

Methods

A retrospective analysis of perianal fistulizing Crohn's patients treated at one specialist IBD unit was performed. Records were reviewed for patient demographics, disease history, clinical assessments, investigation results, and disease flares. Clinical remission was defined as closure of all baseline fistula openings. Radiological healing was defined as the absence of any T2-hyperintense sinuses, tracts, or collections. The primary end-point was rate of MRI healing. The secondary outcome was defined as flare-free period (time between clinical or radiological healing and patients' first signs/symptoms requiring therapy escalation).

Results

A total of 93 patients were included, with a median follow-up of 4.8 years (interquartile range, 2.4-6 years). Of 44 patients, 22 (50%) achieved clinical remission, while 15 of 93 (16%) achieved radiological healing. Of 22 patients, 10 (45%) with clinical remission had a subsequent disease flare (median time of 7 months) compared with 3 of 15 (20%) patients with MRI healing (median time of 3.6 years). Radiological healing was associated with a significantly longer flare-free period (P = 0.01).

Conclusion

Radiological healing occurs less commonly but represents a deeper form of healing, associated with improved long-term clinical outcomes.

Magnetic resonance enterography for predicting the clinical course of Crohn's disease strictures

BACKGROUND AND AIMS

Strictures are the most common Crohn's disease complication, but their natural history is unknown. This study aimed to characterize inflammation, predict prognosis, and understand the impact of drug therapy using magnetic resonance enterography (MRE).

METHODS

Patients with a stricture diagnosed on MRE over a 5-year period were reviewed for MRE disease extent and inflammation, clinical course, C-reactive protein, response to anti-TNF therapy, endoscopic dilatation, hospitalization, and surgery.

RESULTS

136 patients had 235 strictures (77, one and 59, ≥ 2 strictures).

TREATMENT

46% of patients underwent surgery after a median 6 months; median follow-up for those not requiring surgery was 41 months. Predictors of surgery: Hospitalization because of obstruction predicted subsequent surgery (OR 2.50; 95% CI 1.06-5.90) while anti-TNF therapy commenced at stricture diagnosis was associated with a reduced risk (OR 0.23; 95% CI 0.05-0.99). MRE characteristics associated with surgery were proximal bowel dilatation ≥ 30-mm diameter (OR 2.98; 95% CI 1.36-6.55), stricture bowel wall thickness ≥ 10-mm (OR 2.42; 95% CI 1.11-5.27), and stricture length > 5-cm (OR 2.56; 95% CI 1.21-5.43). 81% of patients with these three adverse MRE features required surgery versus 17% if none were present (P < 0.001). Accuracy for these three MRE variables predicting surgery was high (AUC 0.76).

CONCLUSION

Magnetic resonance enterography findings in Crohn's disease strictures are highly predictive of the disease course and the need for future surgery. MRE may also identify who would benefit from treatment intensification. Anti-TNF therapy is associated with reduced risk of surgery and appears to alter the natural history of this complication.

Thiopurine metabolite testing in inflammatory bowel disease

BACKGROUND

Thiopurine use in inflammatory bowel disease (IBD) is limited by drug toxicity and lack of therapeutic efficacy. We assessed the utility of thiopurine metabolite testing and the relationship between disease activity, dose, and metabolite levels in a real world setting.

METHODS

Patients identified from pathology databases (2007-2012) at two tertiary IBD centers were included if they had thiopurines for at least four weeks. Demographics, dose, test indication, clinical status, action taken, and outcome were obtained by retrospective medical record review.

RESULTS

A total of 169 patients were included. 6-Thioguanine (TGN) levels were sub-therapeutic in 52%, therapeutic in 34%, and supratherapeutic in 14%. Test indication was active disease (79%), adverse effect (11%), or adherence assessment (7%). TGN trended lower in the active disease group compared to those with adverse effects (273 (+/- 23.2) versus 447 (+/- 117.7) pmol/8 × 10(8) RBC, P = 0.05). Weight-based dosing did not improve rates of therapeutic TGN levels (under-dosed 31.5% vs standard dose 35.4%), but was significantly associated with shunting toward 6-MMP (23.1% vs 6.8%, P = 0.008, OR = 4.1). Testing resulted in a change in patient treatment in 86% of patients with active disease and subtherapeutic levels and in 68% of tested patients overall.

CONCLUSIONS

Metabolite testing resulted in a change in management in most patients not responding to thiopurines or experiencing adverse events. Weight-based dosing did not increase rates of therapeutic levels but was associated with increased 6MMP shunting.

Inflammatory bowel disease cancer surveillance in a tertiary referral hospital: attitudes and practice

BACKGROUND

Physician adherence to guidelines for colorectal cancer (CRC) surveillance in inflammatory bowel disease (IBD) is often poor. This may lead to adverse patient outcomes and excess endoscopic workload.

AIMS

To assess the attitudes and practice of IBD specialists in a tertiary centre towards colonoscopic surveillance.

METHODS

First, a questionnaire evaluating attitudes and approach to CRC surveillance was issued to 36 clinicians at one tertiary referral hospital. Second, a retrospective audit of IBD surveillance colonoscopy practice over a 2-year period was performed.

RESULTS

Questionnaire response rate was 97%. Sixty-nine per cent of respondents were aware of, and used, Australian guidelines. Surveillance was undertaken by all clinicians in patients with extensive colitis, 83% in patients with left-sided colitis and 51% in patients with proctitis. Seventy-six per cent used chromoendoscopy, and 47% took 10 to 20 random biopsies. Colectomy was considered appropriate in 0% for unifocal low-grade dysplasia, 35% for multifocal low-grade dysplasia and 83% for high-grade dysplasia. Sixty-six per cent would remove elevated dysplastic lesions endoscopically. The audit identified 103 surveillance colonoscopies in 81 patients. Chromoendoscopy was used in 21% of cases, and the median number of random biopsies was 13. Sixty-two per cent of colonoscopies were performed outside the guidelines in relation to colonoscopic frequency. Following colonoscopy, an appropriate recommendation for subsequent surveillance was documented in 40% of cases.

CONCLUSIONS

Knowledge and practice of CRC surveillance in IBD vary among specialist clinicians and often deviate from guidelines. Many clinicians perform surveillance earlier and more frequently than recommended. These findings have implications for patient outcomes and workload.

Addition of thiopurines can recapture response in patients with Crohn's disease who have lost response to anti-tumor necrosis factor monotherapy

BACKGROUND AND AIM

Anti-tumor necrosis factor (TNF) antibodies are effective in maintaining remission in Crohn's disease. However, a significant proportion of patients lose response to these agents with time. This study aimed to determine whether the introduction of a thiopurine in patients who have lost response to anti-TNF monotherapy results in regained response.

METHODS

Five patients (four males; aged 22-38 years) with active Crohn's disease, who had an initial response to anti-TNF therapy but had lost response, were commenced on azathioprine or mercaptopurine at standard doses while continuing anti-TNF therapy. All had previously failed thiopurine therapy prior to starting anti-TNF treatment.

RESULTS

All patients experienced improved clinical symptoms within 2-6 months, with benefit sustained over a mean follow-up of 19 months. Two patients with an elevated C-reactive protein at the time of thiopurine addition demonstrated a fall in C-reactive protein. Colonoscopy before and after thiopurine addition in four patients showed improvement in all, with mucosal healing achieved in two. No adverse effects of treatment were noted.

CONCLUSIONS

Addition of a thiopurine in patients who have lost response to anti-TNF monotherapy is an effective strategy to recapture response even if the patient has previously failed thiopurine therapy. Thiopurines may reduce immunogenicity or act synergistically with anti-TNF therapy.

Determination of dose rate from Chernobyl-derived radiocaesium in Estonian soil

The deposition and vertical depth distribution of 134Cs and 137Cs in the natural undisturbed soil profiles down to 20-25 cm were studied at locations in the North Eastern Estonia, which were most strongly affected by the Chernobyl fallout in 1986. The total depositions were estimated based on summing the sampled and measured activities of 134Cs and 137Cs in all sections of soil profiles. The Chernobyl 137Cs deposition values varied considerably from site to site and the range was from 3.9 kBq m(-2) to 50.2 kBq m(-2), with the average of 22.8 kBq m(-2) for the region (reference data May 1, 1986). The ratio of total activities, A(134Cs)/A(137Cs), varied in the range from 0.47 to 0.55. Using a compartment model and the observed data on the 134Cs and 137Cs activity concentrations (Bq m(-2)) in four compartments, 0-1 cm, 1-5 cm, 5-15 cm and 15-30 cm, of soil collected in 1991-2003, the approximate residence half-times of radiocaesium in soil were determined. The latter increased from 3.7 y in the top-most compartment to 8.6 y and 36.4 y in the deeper compartments, respectively. The time dependence of the external gamma-dose rate at the height of 1 m above a flat ground area arising from the deposited and migrating radiocaesium was calculated using the modeled data on the 134Cs and 137Cs activity in soil compartments. Considering the total depositions of radiocaesium in soil from the Chernobyl 1986 accident, the 50 year effective doses caused by external gamma exposure varied in the range from 0.13 mSv to 1.74 mSv, with the mean of 0.79 mSv in the region.

Comparison of clinical characteristics and management of inflammatory bowel disease in Hong Kong versus Melbourne

BACKGROUND AND AIM

Inflammatory bowel disease (IBD), common in Melbourne, was rare but is now increasing in incidence in Hong Kong (HK). To investigate whether these are the same diseases in the West and East, potential causes of changing incidence, and to plan resource needs, an appreciation of clinical characteristics in contrasting populations is essential.

METHODS

Disease characteristics were collected from prospectively populated IBD databases in two specialist centers in Melbourne, Australia and HK.

RESULTS

Of 795 patients (Crohn's disease [CD] : ulcerative colitis [UC] Melbourne 272:159 and HK 161:203), the age of diagnosis was higher, there were proportionally more male patients with CD but no UC sex difference, fewer patients were current or ex-smokers (CD 8% vs 50%; UC 17% vs 35%) and a family history of IBD was less common (2% vs 11%; P < 0.001) in HK compared to Melbourne. Stricturing and perianal CD were more common in HK (12% vs 6%; P < 0.001; and 29% vs 16%; P = 0.001, respectively). In HK for UC, more patients had extensive disease at diagnosis (42% vs 22%) but colectomy was less common (7% vs 20%; P < 0.001). In Melbourne there was greater steroid use at diagnosis and patients were more likely to receive an immunomodulator or anti-tumor necrosis factor agent.

CONCLUSIONS

IBD in HK was diagnosed at an older age, and had more complicated disease behavior than in Melbourne. Medical therapy, however, was less intense in HK. These differences may relate to real differences in disease or delayed diagnosis due to late presentation and less disease recognition in HK.

A unique clinical phenotype of primary sclerosing cholangitis associated with Crohn's disease

BACKGROUND AND AIMS

A distinct clinical phenotype has been demonstrated for ulcerative colitis with concomitant primary sclerosing cholangitis (PSC). The course and behaviour of Crohn's disease (CD) with PSC has, in contrast, never been defined. We aimed to define the characteristics of patients with concomitant PSC and CD.

METHODS

The Oxford PSC and IBD databases were abstracted for: PSC subtype, date of diagnosis, symptom onset, smoking history, Mayo Clinic PSC score and outcomes (hepatic failure, liver transplantation, Montréal CD classification, treatment, cancer and death). Patients with PSC/CD were matched 1:2 to two control groups: one with PSC/UC and one with isolated CD.

RESULTS

240 patients with PSC were identified; 32 (13%) with CD, 129 (54%) with co-existing UC, and 79 had PSC without IBD. For PSC/CD vs. CD controls, isolated ileal CD was less common (6% vs. 31%, p=0.03). Smoking was less common in PSC/CD (13% vs. 34%, p=0.045). No difference in the distribution of CD, or treatment required was observed. For PSC/CD vs. PSC/UC controls, more patients with PSC/CD were female (50% vs. 28%, p=0.021). 22% of PSC/CD patients had small duct PSC compared with 6% with PSC/UC, (p=0.038). Major event-free survival was prolonged in the PSC/CD group compared with PSC/UC, (Cox regression p=0.04).

CONCLUSION

Unlike PSC/UC, patients with PSC/CD were as likely to be female as male, more commonly had small duct PSC and less commonly progressed to cancer, liver transplantation, or death. Compared to patients with isolated CD, patients with PSC/CD were less likely to smoke or have ileal disease.

A mechanistic model for fate and removal of estrogens in biological nutrient removal activated sludge systems

Two estrogen fate and transformation models were integrated with a comprehensive activated sludge model (ASM) to predict estrogen removal based on biomass and solids production. Model predictions were evaluated against published full-scale plant data as well as results from a laboratory-scale sequencing batch reactor (SBR) fed synthetic wastewater. The estrogen fate model relating the rate of total estrogen degradation to soluble estrogen concentrations successfully predicted estrogen removals when compared with measured concentrations. Model fit 17α-ethinylestradiol (EE2) biodegradation rate constant was 19 to 43% of the estrone (E1) value and 31 to 72% of the 17β-estradiol (E2) value.

The protein C pathway in inflammatory bowel disease: the missing link between inflammation and coagulation

Traditionally described as a major anti-coagulant system, the protein C (PC) pathway, consisting of thrombomodulin, the endothelial cell protein C receptor and activated PC (APC), is gaining increasing attention as an important regulator of microvascular inflammation. Although they possess several anti-inflammatory and cytoprotective functions, the expression and function of the components of the PC pathway is downregulated during inflammation. Recent evidence suggests that the PC pathway is defective in patients with inflammatory bowel disease (IBD) and that restoring its function has anti-inflammatory effects on cultured intestinal microvascular endothelial cells and in animal models of colitis. Here, we propose that the PC pathway has an important role in governing intestinal microvascular inflammation and might provide a novel therapeutic target in the management of IBD.

Glycosylation changes in hFUT1 transgenic mice increase TCR signaling and apoptosis resulting in thymocyte maturation arrest

Glycosylation of cell surface proteins is important in thymocyte maturation. In particular, the level of sialylation of key glycoproteins such as CD45 is believed to play a major role in regulating TCR signaling, adhesion and apoptosis of developing thymocytes. We show here that transgenic expression of human alpha1-2 fucosyltransferase (hFUT1) in mice resulted in a marked shift from sialylation to fucosylation of thymocyte glycoproteins. This was associated with a significant reduction in thymocyte number, an increased rate of apoptosis in double positive and single positive thymocytes, and a maturation arrest at TCR-dependent developmental transitions reminiscent of CD45 deficiency. Indeed, CD45RB dimerization was elevated in hFUT1 thymocytes, consistent with its hyposialylation, and there was a corresponding increase in phosphorylation of the TCR-associated protein Lck. However, contrary to the reduced TCR signaling in CD45 null mice, basal and stimulated TCR signaling was higher in hFUT1 thymocytes than in wild type thymocytes. Our results therefore demonstrate that aberrant expression of a single glycosyltransferase can profoundly affect thymopoiesis, although the relative involvement of CD45-dependent and -independent mechanisms is yet to be determined.

Measurement of faecal fat excretion: an evaluation of attitudes and practices of Australian gastroenterologists

BACKGROUND

Although faecal fat excretion over 72 h is the gold standard for quantifying fat malabsorption, there has been a push from chemical pathology laboratories to discontinue this test, arguing that it is unreliable and of limited clinical value.

AIMS

To assess attitudes, knowledge and practices of Australian gastroenterologists in relation to the test and to gauge opinion as to whether it should remain available.

METHODS

A self-administered questionnaire was developed to assess attitudes towards, patterns of use and understanding of 72-h faecal fat collections. This was posted to all members of the Gastroenterological Society of Australia.

RESULTS

Of 429 eligible gastroenterologists, 124 (29%) responded. Eighty-two per cent utilized the test; 62% at least once per year. Main indications were suspected steatorrhoea (55%), unexplained chronic diarrhoea (39%) or weight loss (29%). Thirty-eight per cent ordered the test to determine stool volume. Only 26% attempted to appropriately fat load patients and approximately half did not recognize the potential influence of medications and stool volume. This was also reflected in poor interpretation of results in specific clinical scenarios. Of those who use the test at least once per year, 97% wanted its continued availability and 51% felt their practice would be significantly affected if the test was discontinued.

CONCLUSIONS

Although continued availability of 72-h faecal fat estimation is supported by many Australian gastroenterologists, the test appears to be often performed and interpreted suboptimally. Rather than discard the test, efforts should more appropriately be directed to improving baseline knowledge to ensure its optimal performance and interpretation.

Effect of light and humus on survival and height growth of ash (Fraxinus excelsior L.) seedlings

In  1997, 300 3-month-old ash (Fraxinus excelsior L.) seedlings were removed out of the three    different humus types (100 seedlings from each humus type) in the  experimental forest of    Aelmoeseneie (University of Ghent) with a closed canopy, in north of  Belgium. Humus types were    described as active mull with pH of 5.3-6.5, acid mull with pH of 4.4-5.2  and moder mull with pH of    3.8-4.3. Seedlings were transplanted in plastic pots, filled by the  original soil, and placed under five    levels of light intensity (2.5, 10, 18,28 and 92%), inside and outside the  forest. Only with 92% light    intensity seedlings were watered as necessary to avoid any appreciable  water deficit.    The results after 1 growing season revealed that seedlings attained a very  high survival rate    (95.3%). Survival was the highest when seedlings grew under semi-closed  canopy (10, 18, and    28%) and also outside the forest at the 92% light intensity, compared with  those under closed    canopy (2.5%). It also confirmed that ash seedlings are shade tolerant, but  with little growth.    Height growth indicated an increasing growth response to nutrient  availability with increasing light    intensity. In fact, minimum height growth was observed in lower light  intensities (2.5 and 10%) and    the maximum value in higher light intensities (28 and 92%). Height growth  of ash seedlings    increased at humus types of active and acid mull, compared with moder  mull.    At the end of the first growing season, lack of differences in survival  rate and height growth,    produced under 18, 28 and 92% light intensity, revealed that training the  seedlings under semiclosed    canopy (18 and 26%) has a preference to those under relatively full  daylight (92%)    associated with watering. Therefore, the first year observations showed  that ash seedlings, either in    view of stem quality and growth or with regard to the facilities of  maintenance, are preferable to be    trained under intermediate light intensities (preferably 28%), at the high  nutritional humus (active    and acid mull).