A Systematic Review on Long-Term Efficacy Outcome Measures in Crohn's Disease Patients

BACKGROUND

The traditional long-term treatment goal of Crohn's disease [CD] is maintenance of corticosteroid-free clinical remission. Additional treatment targets, such as biochemical, endoscopic and patient-reported remission, are advocated. The relapsing-remitting nature of CD provides a challenge to the timing of target assessment. Cross-sectional assessment at predetermined moments disregards the health state in between measurements. In this systematic review, we provide an overview of outcomes used to assess long-term efficacy in clinical trials in CD.

METHODS

A systematic search of the PubMed and EMBASE databases was performed to identify clinical trials in luminal CD reporting on maintenance treatment [strategies] since 1995. Two independent reviewers selected eligible articles for full text retrieval, and assessed if long-term corticosteroid-free clinical, biochemical, endoscopic or patient-reported efficacy outcomes were used.

RESULTS

The search resulted in 2452 hits and 82 articles were included. Clinical activity was used in 80 studies [98%] as the long-term efficacy outcome, and in 21 [26%] of these concomitant corticosteroid use was taken into account. C-reactive protein was used in 32 studies [41%], faecal calprotectin in 15 studies [18%], endoscopic activity in 34 studies [41%] and patient-reported outcome in 32 studies [39%]. In seven studies, clinical, biochemical, endoscopic activity and the patient's perspective were measured. In most studies cross-sectional measures or multiple measurements over time were used.

CONCLUSION

In none of the published clinical trials in CD was sustained remission on all treatment targets reported. Cross-sectional outcomes at predetermined times were widely applied, leading to lack of information regarding sustained corticosteroid-free remission for this relapsing-remitting chronic disease.

Implications of Tioguanine Dosing in IBD Patients with a TPMT Deficiency

Tioguanine is metabolised by fewer enzymatic steps compared to azathioprine and mercaptopurine, without generating 6-methylmercaptopurine ribonucleotides. However, thiopurine S-methyl transferase (TPMT) plays a role in early toxicity in all thiopurines. We aimed to describe the hazards and opportunities of tioguanine use in inflammatory bowel disease (IBD) patients with aberrant TPMT metabolism and propose preventative measures to safely prescribe tioguanine in these patients. In this retrospective cohort study, all determined TPMT genotypes (2016-2021) were evaluated for aberrant metabolism (i.e., intermediate and poor TPMT metabolisers). Subsequently, all IBD patients on tioguanine with aberrant TPMT genotypes were evaluated for tioguanine dosages, adverse drug events, lab abnormalities, treatment duration and effectiveness. TPMT genotypes were determined in 485 patients, of whom, 50 (10.3%) and 4 patients (0.8%) were intermediate and poor metabolisers, respectively. Of these patients, 12 intermediate and 4 poor TPMT metabolisers had been prescribed tioguanine in varying doses. In one poor TPMT metaboliser, tioguanine 10 mg/day induced delayed pancytopenia. In general, reduced tioguanine dosages of 5 mg/day for intermediate TPMT metabolisers, and 10 mg two-weekly for poor TPMT metabolisers, resulted in a safe, long-term treatment strategy. Diminished or absent TPMT enzyme activity was related with a pharmacokinetic shift of tioguanine metabolism which is associated with relatively late-occurring myelotoxicity in patients on standard tioguanine dose. However, in strongly reduced dose regimens with strict therapeutic drug and safety monitoring, tioguanine treatment remained a safe and effective option in IBD patients with dysfunctional TPMT.

Superior Effectiveness of Tofacitinib Compared to Vedolizumab in Anti-TNF-experienced Ulcerative Colitis Patients: A Nationwide Dutch Registry Study

BACKGROUND & AIMS

Clinicians face difficulty in when and in what order to position biologics and Janus kinase inhibitors in patients with anti-tumor necrosis factor-alpha (TNF) refractory ulcerative colitis (UC). We aimed to compare the effectiveness and safety of vedolizumab and tofacitinib in anti-TNF-exposed patients with UC in our prospective nationwide Initiative on Crohn and Colitis Registry.

METHODS

Patients with UC who failed anti-TNF treatment and initiated vedolizumab or tofacitinib treatment were identified in the Initiative on Crohn and Colitis Registry in the Netherlands. We selected patients with both clinical as well as biochemical or endoscopic disease activity at initiation of therapy. Patients previously treated with vedolizumab or tofacitinib were excluded. Corticosteroid-free clinical remission (Simple Clinical Colitis Activity Index ≤2), biochemical remission (C-reactive protein ≤5 mg/L or fecal calprotectin ≤250 μg/g), and safety outcomes were compared after 52 weeks of treatment. Inverse propensity score-weighted comparison was used to adjust for confounding and selection bias.

RESULTS

Overall, 83 vedolizumab- and 65 tofacitinib-treated patients were included. Propensity score-weighted analysis showed that tofacitinib-treated patients were more likely to achieve corticosteroid-free clinical remission and biochemical remission at weeks 12, 24, and 52 compared with vedolizumab-treated patients (odds ratio [OR], 6.33; 95% confidence interval [CI], 3.81-10.50; P < .01; OR, 3.02; 95% CI, 1.89-4.84; P < .01; and OR, 1.86; 95% CI, 1.15-2.99; P = .01; and OR, 3.27; 95% CI, 1.96-5.45; P < .01; OR, 1.87; 95% CI, 1.14-3.07; P = .01; and OR, 1.81; 95% CI, 1.06-3.09; P = .03, respectively). There was no difference in infection rate or severe adverse events.

CONCLUSIONS

Tofacitinib was associated with superior effectiveness outcomes compared with vedolizumab in anti-TNF-experienced patients with UC along with comparable safety outcomes.

Exposure to thioguanine during 117 pregnancies in women with inflammatory bowel disease

BACKGROUND

Safety of thioguanine in pregnant patients with inflammatory bowel disease (IBD) is sparsely recorded. This study was aimed to document the safety of thioguanine during pregnancy and in birth.

METHODS

In this multicenter case series, IBD patients treated with thioguanine during pregnancy were included. Data regarding disease and medication history, pregnancy course, obstetric complications and neonatal outcomes were collected.

RESULTS

Data on 117 thioguanine-exposed pregnancies in 99 women were collected. Most (78%) had Crohn's disease and the mean age at delivery was 31 years. In eighteen pregnancies (15%) IBD flared. Obstetric and infectious complications were seen in 15% (n=17) and 7% (n=8) of pregnancies, respectively. Ten pregnancies (8.5%) resulted in a first trimester miscarriage and one in a stillbirth at 22 weeks gestational age. Congenital abnormalities were observed in one induced abortion (trisomy 21) and in one of the live-born children (cleft palate) . In total 109 neonates were born from 101 singleton pregnancies and 4 twin pregnancies. In the singleton pregnancies, ten children were born prematurely and ten were born small for gestational age. Screening for myelosuppresion was performed in sixteen neonates (14.7%); two had anemia in umbilical cord blood. All outcomes were comparable to either the general Dutch population or to data from 3 Dutch cohort studies on the use of conventional thiopurines in pregnant IBD patients.

CONCLUSION

In this large case series the use of thioguanine during pregnancy is not associated in excess with adverse maternal or neonatal outcomes.

A report on the potential of Rac1/pSTAT3 protein levels in T lymphocytes to assess the pharmacodynamic effect of thiopurine therapy in Inflammatory Bowel Disease patients

The thiopurine derivatives azathioprine (AZA), mercaptopurine (MP) and tioguanine (TG) remain standard treatment of inflammatory bowel disease (IBD). The immune suppressive effect of thiopurines is primarily based on blocking the Ras-related C3 botulinum toxin substrate 1 (Rac1) causing apoptosis of T lymphocytes by inhibition of the phosphorylated downstream transcription factor Signal Transducer and Activator of Transcription 3 (pSTAT3). A functional pharmacodynamic marker in T lymphocytes may be useful to predict therapeutic outcome of thiopurine therapy. The aim of this study was to explore whether protein levels of Rac1 and pSTAT3 in T lymphocytes may be applied as a specific pharmacodynamic marker for thiopurine therapy in IBD patients. Rac1 and pSTAT3 protein levels in T lymphocytes were explored in 57 IBD patients (median age 51 years, 56% female), subdivided into six groups based on IBD activity and its treatment: patients with active disease without IBD maintenance medication (1) or patients in remission on AZA/MP (2), TG (3), infliximab (IFX) (4), thiopurine and IFX combination-treatment (5) or without IBD medication (6). Reference values were obtained from healthy subjects. Rac1 and pSTAT3 protein levels in T lymphocytes from patients on thiopurine monotherapy (group 2 and 3) were compared to the other groups, and to healthy subjects. Absolute Rac1 and pSTAT3 protein levels showed no differences between the thiopurine monotherapy groups when compared to patients with active disease. However, the ratio of Rac1 and pSTAT3 protein levels was lower in thiopurine patients groups compared to patients with active disease. Rac1-corrected pSTAT3 protein levels may serve as a pharmacodynamic marker of thiopurine monotherapy and may be a potential tool to predict therapeutic effectiveness in IBD patients.

Clinical Outcomes of Covid-19 in Patients With Inflammatory Bowel Disease: A Nationwide Cohort Study

BACKGROUND AND AIMS

The COVID-19 risk and disease course in inflammatory bowel disease [IBD] patients remains uncertain. Therefore, we aimed to assess the clinical presentation, disease course, and outcomes of COVID-19 in IBD patients. Second, we determined COVID-19 incidences in IBD patients and compared this with the general population.

METHODS

We conducted a multicentre, nationwide IBD cohort study in The Netherlands and identified patients with COVID-19. First, we assessed the COVID-19 disease course and outcomes. Second, we compared COVID-19 incidences between our IBD study cohort and the general Dutch population.

RESULTS

We established an IBD cohort of 34 763 patients. COVID-19 was diagnosed in 100/34 763 patients [0.29%]; 20/100 of these patients [20%] had severe COVID-19 defined as admission to the intensive care unit, mechanical ventilation, and/or death. Hospitalisation occurred in 59/100 [59.0%] patients and 13/100 [13.0%] died. All patients who died had comorbidities and all but one were ≥65 years old. In line, we identified ≥1 comorbidity as an independent risk factor for hospitalisation (odds ratio [OR] 4.20, 95% confidence interval [CI] 1.58-11.17,; p = 0.004). Incidences of COVID-19 between the IBD study cohort and the general population were comparable (287.6 [95% CI 236.6-349.7] versus 333.0 [95% CI 329.3-336.7] per 100000 patients, respectively; p = 0.15).

CONCLUSIONS

Of 100 cases with IBD and COVID-19, 20% developed severe COVID-19, 59% were hospitalised and 13% died. A comparable COVID-19 risk was found between the IBD cohort [100/34 763 = 0.29%] and the general Dutch population. The presence of ≥1 comorbidities was an independent risk factor for hospitalisation due to COVID-19.

Severe COVID-19 in inflammatory bowel disease patients in a population-based setting

OBJECTIVE

Data on the course of severe COVID-19 in inflammatory bowel disease (IBD) patients remains limited. We aimed to determine the incidence rate and clinical course of severe COVID-19 in the heavily affected South-Limburg region in the Netherlands.

METHODS

All COVID-19 patients admitted to the only two hospitals covering the whole South-Limburg region between February 27, 2020 and January 4, 2021 were included. Incidence rates for hospitalization due to COVID-19 were determined for the IBD (n = 4980) and general population (n = 597,184) in South-Limburg.

RESULTS

During a follow-up of 4254 and 510,120 person-years, 20 IBD patients (0.40%; 11 ulcerative colitis (UC), 9 Crohn's disease (CD)) and 1425 (0.24%) patients from the general population were hospitalized due to proven COVID-19 corresponding to an incidence rate of 4.7 (95% Confidence interval (CI) 3.0-7.1) and 2.8 (95% CI 2.6-2.9) per 1000 patient years, respectively (Incidence rate ratio: 1.68, 95% CI 1.08-2.62, p = 0.019). Median age (IBD: 63.0 (IQR 58.0-75.8) years vs. general population: 72.0 (IQR 62.0-80.0) years, p = 0.10) and mean BMI (IBD: 24.4 (SD 3.3) kg/m2 vs. general population 24.1 (SD 4.9) kg/m2, p = 0.79) at admission were comparable in both populations. As for course of severe COVID-19, similar rates of ICU admission (IBD: 12.5% vs. general population: 15.7%, p = 1.00), mechanical ventilation (6.3% vs. 11.2%, p = 1.00) and death were observed (6.3% vs. 21.8%, p = 0.22).

CONCLUSION

We found a statistically significant higher rate of hospitalization due to COVID-19 in IBD patients in a population-based setting in a heavily impacted Dutch region. This finding reflects previous research that showed IBD patients using systemic medication were at an increased risk of serious infection. However, although at an increased risk of hospitalization, clinical course of severe COVID-19 was comparable to hospitalized patients without IBD.

Cohort Profile: The Christchurch IBS cOhort to investigate Mechanisms FOr gut Relief and improved Transit (COMFORT)

BACKGROUND AND AIMS

This cross-sectional observational case-control study was initiated in July 2016 with the aim of increasing an understanding of the underlying disease mechanisms in functional gastrointestinal disorders (FGIDs) including irritable bowel syndrome (IBS), functional diarrhoea (FD), and functional constipation (FC). Specific areas of interest include the effect of food, microbiome, host and microbial genetics, metabolome, and psychological variables on unexplained chronic gastrointestinal (GI) symptoms.

METHODS

This study recruited consecutive patients who were attending one of two endoscopy centres in Christchurch, New Zealand, for colonoscopy and a subgroup of participants from the general public who did not undergo colonoscopy. Participants with known GI disease other than an FGID were excluded. Those with symptoms were recruited as cases, whilst those without symptoms were recruited as controls. In the days prior to preparation for colonoscopy, or an agreeable time for those not undergoing colonoscopy, demographic, symptom, psychological, dietary, and health data were collected in addition to biological samples (breath, faeces, blood, and urine). Colonic biopsies were taken at the time of colonoscopy from participants in the colonoscopy subgroup.

RESULTS

Between July 2016 and December 2018, 349 participants were recruited, 315 of whom completed the study, 220 participants were from the colonoscopy subgroup, and 95 from the non-colonoscopy subgroup. This included 129 controls and 186 cases (57 IBS-diarrhoea predominant, 30 IBS-constipation predominant, 41 IBS-mixed, 42 FC, and 16 FD). The mean age of FGID cases was 53.4 years and controls 54.4 years. Cases (149/186, 80.1%) and controls (57/72, 55.8%) were predominantly female. Education levels were similar across the cohort. Smoking and alcohol rates were also similar. Biological samples were collected as planned from participants.

CONCLUSIONS

The COMFORT cohort is a unique clinical cohort of FGID cases and controls with a wide range of demographic, dietary, clinical, psychological, and health data in addition to biological samples. Future research will aim to use a systems biology approach to establish the potential role of diet, host-microbiome interactions, and other factors in the pathogenesis of FGIDs.