Remission Is Maintained after Switch from Dose-Optimised Intravenous Treatment to Subcutaneous Treatment with Vedolizumab in Inflammatory Bowel Disease.

Background and Objectives: The subcutaneous (SC) formulation of vedolizumab has proven to be effective for the maintenance of remission after intravenous induction. Little is known about the efficacy of switching from intravenous maintenance treatment to SC. We aimed to assess the real-world efficacy of switching to SC treatment and to assess the impact of a baseline treatment regimen. Materials and Methods: In this observational cohort study, adult patients with inflammatory bowel disease who were switched to SC vedolizumab maintenance treatment were enrolled. Patients after intravenous induction and patients who switched from intravenous maintenance treatment (every 8 weeks or every 4 weeks) were included. The SC vedolizumab dosing was 108 mg every 2 weeks, regardless of the previous regimen. The clinical, biochemical, and endoscopic disease activity parameters and vedolizumab serum concentrations at the time of the switch and at the follow-up were assessed. Results: In total, 135 patients (38% Crohn's disease, 62% ulcerative colitis) were switched to SC vedolizumab treatment. The median time to the first follow-up (FU) was 14.5 weeks (IQR 12-26), and the median time to the second FU was 40 weeks (IQR 36-52). Nine patients (7%) discontinued SC vedolizumab treatment, with two-thirds of them discontinuing due to active disease. In all dosing regimens, there were no significant changes in the clinical scores and CRP at the baseline and first and second FUs. Clinical and biochemical remission appeared to be maintained irrespective of the previous dosing regimen. Conclusions: The results of this real-world study suggest that the maintenance of clinical and biomarker remission can be achieved in patients who switched from intravenous to SC vedolizumab. The baseline vedolizumab dosing regimen (every 4 weeks versus every 8 weeks) did not have an impact on outcomes.

Comparison of 3 Enzyme-Linked Immunoassay Methods to Evaluate Serum Concentrations of Infliximab and Antibodies to Infliximab in 32 Patients with Moderate to Severe Inflammatory Bowel Disease.

BACKGROUND Monitoring of trough levels and anti-drug antibodies is important when patients with inflammatory bowel disease (IBD) are treated with anti-TNF biologics due to guided therapeutic decisions. The comparability of 3 ELISA tests for detection of the lowest serum concentration of infliximab (IFX) or antibodies to IFX (ATIs) was evaluated. MATERIAL AND METHODS Two commercial assays for measuring IFX levels were compared with the in-house (UHL) test. ATIs were measured with 1 commercial test and compared to the in-house test. According to the guidelines, IFX levels were within the range of 3 to 7 µg/mL. RESULTS The decision to continue therapy would be the same for 11 out of 16 patients when comparing the apDia Infliximab ELISA and UHL test, and for 12 out of 18 patients when comparing the Lisa-Tracker and in-house UHL test. Linear correlations between the tests were R=0.92 (UHL and apDia), R=0.91 (apDia and Lisa-Tracker), and R=0.89 (UHL and Lisa-Tracker) with P<0.001, respectively. CONCLUSIONS As the IFX levels are important for decisions on further therapy, detectable IFX levels realistically reflect the presence of the drug in the patients' blood and thus control inflammatory activity. The tests were found as comparable and performed well in this aspect and might be used in everyday clinical practice.

Performance of European and American Societies of Gastrointestinal Endoscopy Guidelines for Prediction of Choledocholithiasis in Patients with Acute Biliary Pancreatitis.

Background and Objectives: Up to one-third of patients with acute biliary pancreatitis also present with choledocholithiasis. Guidelines from the European Society of Gastrointestinal Endoscopy (ESGE) and the American Society for Gastrointestinal Endoscopy (ASGE) for investigating suspected choledocholithiasis suggest endoscopic retrograde cholangiopancreatography in patients with high-likelihood (ESGE)/high-probability (ASGE) predictors and endoscopic ultrasound in those with intermediate-likelihood (ESGE)/intermediate-probability (ASGE) predictors. Although both guidelines are similar, they are not identical. Furthermore, these algorithms were mainly developed from cohorts of patients without pancreatitis and are therefore poorly validated in a subset of patients with acute pancreatitis. We aimed to assess the performance of the ESGE and ASGE algorithms for the prediction of choledocholithiasis in patients with acute biliary pancreatitis. Materials and Methods: This was a retrospective analysis of 86 consecutive patients admitted to a tertiary referral centre in the year 2020 due to acute biliary pancreatitis. Results: Choledocholithiasis was confirmed in 29/86 (33.7%) of patients (13 with endoscopic retrograde cholangiopancreatography and 16 with endoscopic ultrasound). All 10/10 (100%) ESGE high-likelihood and 14/19 (73.7%) ASGE high-probability patients had choledocholithiasis. Only 19/71 (26.8%) patients with ESGE intermediate likelihood and 15/67 (22.4%) with ASGE intermediate probability had choledocholithiasis. Only 8/13 (61.5%) patients with the ASGE high-probability predictor of dilated common bile duct plus bilirubin > 68.4 µmol/mL had choledocholithiasis. Since this predictor is not considered high likelihood by ESGE, this resulted in a superior specificity of the European compared to the American guideline (100% vs. 91.2%). Following the American instead of the European guidelines would have resulted in five unnecessary endoscopic retrograde cholangiopancreatographies and five unnecessary endoscopic ultrasound examinations. Conclusions: This retrospective analysis suggests that the European guidelines may perform better than the American guidelines at predicting choledocholithiasis in the setting of acute pancreatitis. This was because dilated common bile duct plus bilirubin > 68.4 µmol/mL was not a reliable predictor for persistent bile duct stones.

Peak Concentrations of Ustekinumab After Intravenous Induction Therapy Identify Patients With Crohn's Disease Likely to Achieve Endoscopic and Biochemical Remission.

BACKGROUND & AIMS: Little is known about the relationship between ustekinumab exposure during the first 2 weeks of treatment and outcomes of patients with Crohn's disease (CD). We investigated the relationship between serum concentrations of ustekinumab during the first 2 weeks of treatment and endoscopic and biochemical remission in patients with CD. METHODS: In a prospective observational study, we measured concentrations of ustekinumab in serum samples from 41 consecutive patients who started treatment with ustekinumab (approximately 6 mg/kg, intravenously, then 90 mg every 8 weeks), due to endoscopic markers of active CD, at a single center from October 2017 through January 2019. We measured ustekinumab exposure parameters during the first 2 weeks (peak concentration measured immediately after intravenous infusion, week 2 concentration, and area under the curve through week 2). We investigated the correlation between these parameters and endoscopic remission (simple endoscopic score for CD scores of 3 or less without ulceration, assessed centrally) and biochemical remission (level of fecal calprotectin below 100 mg/kg) using the Mann-Whitney U test. RESULTS: Endoscopic remission was achieved in 10 patients (24.4%) at week 24; biochemical remission was achieved in 17 patients (41.5%) at week 8, 17 patients (41.5%) at week 16, and 21 patients (51.2%) at week 24. Peak concentrations associated with endoscopic remission (area under the receiver operating characteristic curve, 0.717; 95% CI, 0.517-0.916); 6 of 13 patients (46%) with peak concentrations above 105 µg/mL (upper tercile) achieved endoscopic remission, compared with only 1 of 14 patients (7%) with peak concentrations below 88 µg/mL (lower tercile). All exposure parameters during the first 2 weeks were associated with biochemical remission. There was no significant difference between the associations of peak concentrations, week-2 concentrations, area under the curve through week 2, or later exposure measures (at weeks 4 and 8) with biochemical or endoscopic remission. CONCLUSIONS: In a prospective study, we found that serum concentrations of ustekinumab as early as 1 hour after intravenous infusion might be used to identify patients with CD most likely to achieve endoscopic remission. This early measurement might be used to optimize treatment of CD.

Success and safety of high infliximab trough levels in inflammatory bowel disease.

OBJECTIVE: A prospective trial suggests target infliximab trough levels of 3-7 µg/mL, yet data on additional therapeutic benefits and safety of higher trough levels are scarce. AIM: To explore whether high infliximab trough levels (≥7 µg/mL) are more effective and still safe. MATERIAL AND METHODS: In this cohort study of 183 patients (109 Crohn's disease and 74 ulcerative colitis) on infliximab maintenance treatment at a tertiary referral center we correlated fecal calprotectin and C-reactive protein to trough levels (426 samples) at different time points during treatment. Rates of infections were compared in quadrimesters (four-month periods) with high trough levels to quadrimesters with trough levels <7 µg/mL during 420 patient-years. RESULTS: Fecal calprotectin and C-reactive protein (median [interquartile range]) were lower in patients with high trough levels (fecal calprotectin 66 mg/kg [30-257]; C-reactive protein 3 mg/L [3-3]) compared to trough levels below 7 µg/mL (fecal calprotectin 155 mg/kg [72-474]; C-reactive protein 3 mg/L [3-14.5]) (p < .001). High trough levels were superior also after excluding samples with trough levels <3 µg/mL from analysis. No differences in rates of infections were observed in quadrimesters with high trough levels (16/129 [12.4%]) compared to quadrimesters with trough levels <7 µg/mL (32/344 [9.3%]) (p = .32). Maintaining high trough levels resulted in 32% (interquartile range: 2-54%) increase of infliximab consumption. CONCLUSION: High infliximab trough levels provide better control of inflammation in inflammatory bowel disease without increasing the risk of infection.

Down-regulation of microRNAs of the miR-200 family and up-regulation of Snail and Slug in inflammatory bowel diseases - hallmark of epithelial-mesenchymal transition.

Fibrosis is an important feature of inflammatory bowel diseases (IBD), particularly Crohn's disease (CD), but its pathogenesis is poorly understood. To determine the postulated involvement of epithelial-mesenchymal transition (EMT) in the development of fibrosis in IBD, we analysed the expression profiles of the miR-200 family which has been shown to induce EMT in experimental models and various human diseases. We also analysed the expression of Snail and Slug, postulated targets of the investigated microRNAs. Ten patients with ulcerative colitis (UC) and 10 patients with CD who underwent colon resection were included. From each, two tissue samples were chosen (one with the most severely and one with the least affected or normal mucosa) for analysis of microRNAs expression using real-time polymerase chain reaction, and Snail and Slug expression using immunohistochemistry. We found significant down-regulation of all investigated microRNAs in CD, and of three investigated microRNAs in UC, in comparison to the normal or the least affected mucosa. Comparing UC and CD, four microRNAs were significantly more down-regulated in CD than in UC. Snail and Slug were expressed in the injured epithelium and occasionally in mesothelial cells and submesothelial fibroblasts. Our finding of down-regulation of the miR-200 family and up-regulation of transcription repressors Snail and Slug supports the postulated role of EMT in the pathogenesis of fibrosis in IBD. The described expression patterns are consistent with the notion that fibrosis does not occur only in CD but also in UC, being much more severe in CD.

Withdrawal of immunomodulators after co-treatment does not reduce trough level of infliximab in patients with Crohn's disease.

BACKGROUND & AIMS: The addition of immunomodulators increases the efficacy of maintenance therapy with infliximab for up to 1 year in patients with Crohn's disease who have not been previously treated with immunomodulators. However, there are questions about the effect of withdrawing immunomodulator therapy from these patients. We studied the effects of treatment with infliximab and immunomodulators (co-treatment) and then immunomodulator withdrawal on long-term outcomes of patients, as well as trough levels of infliximab and formation of anti-infliximab antibodies (ATI). METHODS: In a retrospective study with the median follow-up period of 34 months (interquartile range, 19-58 months), we analyzed data from 223 patients treated for Crohn's disease between May 1999 and December 2010 at the University Hospitals, Leuven, Belgium (65 received infliximab monotherapy, 158 received infliximab and an immunomodulator). Trough levels of infliximab and levels of ATI were measured in blood samples collected from 117 patients throughout co-treatment, as well as the time of immunomodulator withdrawal and after withdrawal. RESULTS: Patients receiving co-treatment had higher trough levels of infliximab (adjusted mean increase, 1.44-fold) than those receiving infliximab monotherapy (95% confidence interval [CI], 1.07-1.92; P = .02). A smaller percentage of patients receiving co-treatment developed ATI (35 of 158, 22%) than those receiving infliximab monotherapy (25 of 65, 38%; P = .01). Among co-treated patients, levels of infliximab remained stable after immunomodulators were withdrawn (before: 3.2 µg/mL; 95% CI, 1.6-5.8 µg/mL and after: 3.7 µg/mL; 95% CI, 1.3-6.3 µg/mL; P = .70). After withdrawal of immunomodulators, 45 of 117 patients (38%) required increasing doses of infliximab, and 21 of 117 (18%) discontinued infliximab. At the time of immunomodulator withdrawal, trough levels of infliximab and C-reactive protein were most strongly associated with response to infliximab thereafter. CONCLUSIONS: In a retrospective analysis, we confirmed that withdrawal of immunomodulators after at least 6 months (median, 13 months) of co-treatment with infliximab does not reduce the trough levels of infliximab in patients with Crohn's disease. Detectable trough levels of infliximab at the time of immunomodulator withdrawal are associated with long-term response.

Early trough levels and antibodies to infliximab predict safety and success of reinitiation of infliximab therapy.

BACKGROUND & AIMS: Few agents are available for the treatment of inflammatory bowel diseases, and patients frequently become unresponsive to biologics. We investigated the feasibility of reinitiating infliximab therapy for patients who previously received only episodic therapy with, lost response to, or had infusion reactions to infliximab. We also aimed to identify factors associated with the success and safety of restarting infliximab, such as antibodies to infliximab and trough levels of the drug. METHODS: From the inflammatory bowel disease biobank, we identified 128 consecutive patients (105 patients with Crohn's disease, 23 patients with ulcerative colitis) who restarted infliximab after a median 15-month discontinuation (range, 6-125 mo; 28 patients for loss of response or infusion reactions, 100 patients for remission or pregnancy). We also analyzed serum samples that had been collected during the first period of infliximab therapy (T-1), when therapy was reinitiated (T0), and at later time points (T+1, T+2) for trough levels and antibodies to infliximab. We investigated correlations among response to treatment, infusion reactions, treatment modalities, trough levels, and antibodies to infliximab. RESULTS: Reinitiation of infliximab therapy produced a response in 84.5% of patients at week 14, 70% of patients at 1 year, and in 61% of patients at more than 4 years. Fifteen patients had acute infusion reactions and 10 patients had delayed infusion reactions. The absence of antibodies to infliximab at T+1 (hazard ratio [HR], 0.14; 95% confidence interval [CI], 0.026-0.74; P = .021) and reinitiation with concomitant immunomodulator therapy were associated with short-term responses (HR, 6.0; 95% CI, 1.3-27; P = .019). Pregnancy or remission as reason for discontinuation (HR, 2.70; 95% CI, 1.09-6.67; P = .033) and higher trough levels at T+1 (HR, 2.94; 95% CI, 1.18-7.69; P = .021) were associated with long-term response. Undetectable antibodies to infliximab at T+1 were associated with the safety of reinitiating therapy (HR for infusion reaction with detectable antibodies to infliximab, 7.7; 95% CI, 1.88-31.3; P = .004). CONCLUSIONS: Reinitiating infliximab therapy can be safe and effective for patients with Crohn's disease or ulcerative colitis after a median 15-month discontinuation period.

Biological treatment approach to inflammatory bowel disease is similar in academic and nonacademic centres - prime time for decentralisation of inflammatory bowel disease care?

BACKGROUND: With the increasing number of inflammatory bowel disease (IBD) patients, it is difficult to manage them within specialised IBD teams in academic medical centres: many are therefore treated in nonacademic IBD centres. It is unclear whether the time to introducing biologics is the same in both settings. AIM: We aimed to compare treatment approach with biologics in academic vs. nonacademic centres. METHODS: We analysed Slovenian national IBD registry data (UR-CARE Registry, supported by the European Crohn's and Colitis Organisation), which included 2 academic (2319 patients) and 4 nonacademic IBD (429 patients) centres. RESULTS: The disease phenotype was similar in both settings. In total, 1687 patients received 2782 treatment episodes with biologics. We observed no differences in treatment episodes with TNF-alpha inhibitors (60% vs. 61%), vedolizumab (24% vs. 23%), or ustekinumab (17% vs. 16%) in academic compared to nonacademic centres ( P  = 0.949). However, TNF inhibitors were less often the first biologic in academic centres (TNF inhibitors: 67.5% vs. 74.0%, vedolizumab: 20.3% vs. 17.9%, ustekinumab: 12.1% vs. 8.1%; P = 0.0096). Consequently, more patients received ustekinumab (29.8% vs. 18.3%) and vedolizumab (17.4% vs. 13.5%) and fewer TNF inhibitors (52.7% vs. 68.2%) for Crohn's disease in academic compared to nonacademic centres, with no such differences for ulcerative colitis. The time to initiation of the first biologic from diagnosis was short and similar in both settings (11.3 vs. 10.4 months, P  = 0.2). CONCLUSION: In this nationwide registry analysis, we observed that biological treatment choice was similar in academic and nonacademic settings. These findings support the decentralisation of IBD care.

Biopsies from ulcer edge yield higher histological activity scores than biopsies from non-ulcerated mucosa in active ulcerative colitis.

BACKGROUND: The appropriate location for biopsy collection in ulcerative colitis is unknown. OBJECTIVES: We aimed to determine the location for biopsy collection in the presence of ulcers which yields the highest histopathological score. DESIGN AND METHODS: This prospective cross-sectional study enrolled patients with ulcerative colitis and ulcers in the colon. Biopsy specimens were obtained at the edge of the ulcer; at a distance of one open forceps (7-8 mm) from the ulcer edge; at a distance of three open forceps (21-24 mm) from the ulcer edge; further referred to as locations 1, 2 and 3 respectively. Histological activity was assessed using Robarts Histopathology Index and the Nancy Histological Index. Statistical analysis was performed using mixed effects models. RESULTS: A total of 19 patients were included. Decreasing trends with distance from the ulcer edge ( P  < 0.0001) were observed. Biopsies procured from the edge of the ulcer (location 1) yielded a higher histopathological score compared to biopsies procured at locations 2 and 3 ( P  ≤ 0.001). CONCLUSION: Biopsies from the ulcer edge yield higher histopathological scores than biopsies next to the ulcer. In clinical trials with histological endpoints, biopsies should be obtained from the ulcer edge (if ulcers are present) to reliably assess histological disease activity.

Non-hepatic Solid Organ Transplant in Patients with Inflammatory Bowel Disease: An ECCO CONFER Multicentre Case Series.

BACKGROUND AND AIMS: Solid organ transplantation, with the exception of liver, has rarely been reported in patients affected by inflammatory bowel diseases [IBD]. METHODS: This is an ECCO-CONFER project collecting cases of solid organ transplants [with the exclusion of liver] that were performed in IBD patients. We evaluated the change in the IBD therapy, need for bowel resection due to medically refractory IBD, or need for hospitalisation due to IBD relapse ['severe IBD course'] before and after transplantation. RESULTS: in total, 34 organ transplantations [28 kidney, five heart, one lung] in 33 IBD patients were collected [67% male, 55% Crohn's disease, mean age 53 ±â€…16 years]. The median follow-up was 4.3 years (interquartile range [IQR] 3.2-10.7); 29 patients [87.9%] were treated with tacrolimus, 25 [76%] with systemic steroids, 22 [67%] with mycophenolate mofetil, 11 [33%] with everolimus, six with cyclosporine [18%]. One patient was treated with infliximab, two patients with adalimumab, two patients with vedolizumab, one patient with ustekinumab. Overall, a severe IBD course was observed in three [9.3%] patients before transplantation and in four [11.7%] in the post-transplant setting [p = 0.26]. Three cases of cancer [excluding skin non-melanoma] [9.1%] were recorded in the post-transplantation period versus two in the pre-transplantation period [6.1%, p = 0.04]. Six patients [18.2%] died during the period of observation. No deaths were associated with IBD or complications of the transplant. CONCLUSIONS: In IBD patients, solid organ transplantation does not seem to impact on the IBD severity. However, the risk of malignancy needs further investigation.

Comparison of Short- and Long-Term Effectiveness between Anti-TNF and Ustekinumab after Vedolizumab Failure as First-Line Therapy in Crohn's Disease: A Multi-Center Retrospective Cohort Study.

BACKGROUND: The effectiveness of anti-TNF or ustekinumab (UST) as a second-line biologic after vedolizumab (VDZ) failure has not yet been described. AIMS AND METHODS: In this retrospective multicenter cohort study, We aim to investigate the effectiveness of anti-TNF and UST as second-line therapy in patients with Crohn's disease (CD) who failed VDZ as a first-line treatment. The primary outcome was clinical response at week 16-22. Secondary outcomes included the rates of clinical remission, steroid-free clinical remission, CRP normalization, and adverse events. RESULTS: Fifty-nine patients who failed on VDZ as a first-line treatment for CD were included; 52.8% patients received anti-TNF and 47.2% UST as a second-line therapy. In initial period (Week 16-22), the clinical response and remission rate was similar between both groups: 61.2% vs. 68%, p = 0.8 and 48.3% vs. 56%, p = 0.8 on anti-TNF and UST therapy, respectively. Furthermore, in the maintenance period the rate was similar: 75% vs. 82.3%, p = 0.8 and 62.5% vs. 70.5%, p = 0.8, respectively. Of the patients, 12 out of the 59 stopped the therapy, without a significant difference between the two groups (p = 0.6). CONCLUSION: Second-line biological therapy after VDZ failure therapy was effective in >60% of the patients with CD. No differences in effectiveness were detected between the use of anti-TNF and UST as a second line.

Real-Life Efficacy of Tofacitinib in Various Situations in Ulcerative Colitis: A Retrospective Worldwide Multicenter Collaborative Study.

BACKGROUND AND AIMS: Tofacitinib (TFB) appears to be effective in the treatment of ulcerative colitis (UC); however, available real-world studies are limited by cohort size. TFB could be an option in the treatment of acute severe ulcerative colitis (ASUC). We aimed to investigate efficacy and safety of TFB in moderate-to-severe colitis and ASUC. METHODS: This retrospective, international cohort study enrolling UC patients with ≥6-week follow-up period was conducted from February 1 to July 31, 2022. Indications were categorized as ASUC and chronic activity (CA). Baseline demographic and clinical data were obtained. Steroid-free remission (SFR), colectomy, and safety data were analyzed. RESULTS: A total of 391 UC patients (median age 38 [interquartile range, 28-47] years; follow-up period 26 [interquartile range, 14-52] weeks) were included. A total of 27.1% received TFB in ASUC. SFR rates were 23.7% (ASUC: 26.0%, CA: 22.8%) at week 12 and 41.1% (ASUC: 34.2%, CA: 43.5%) at week 52. The baseline partial Mayo score (odds ratio [OR], 0.850; P = .006) was negatively associated with week 12 SFR, while biologic-naïve patients (OR, 2.078; P = .04) more likely achieved week 52 SFR. The colectomy rate at week 52 was higher in ASUC group (17.6% vs 5.7%; P < .001) and decreased with age (OR, 0.94; P = .013). A total of 67 adverse events were reported, and 17.9% resulted in cessation of TFB. One case of thromboembolic event was reported. CONCLUSIONS: TFB is effective in both studied indications. TFB treatment resulted in high rates of SFR in the short and long terms. Higher baseline disease activity and previous biological therapies decreased efficacy. No new adverse event signals were found.

Contemporary Management of Postoperative Crohn's Disease after Ileocolonic Resection.

Surgery remains an important treatment modality in the multidisciplinary management of patients with Crohn's disease (CD). To illustrate the recent advances in the management of postoperative CD we outline the contemporary approach to treatment: diagnosing disease recurrence using endoscopy or noninvasive methods and risk stratification underlying decisions to institute treatment. Endoscopic scoring indices are being refined to guide treatment decisions by accurately estimating the risk of recurrence based on endoscopic appearance. The original Rutgeerts score has been modified to separate anastomotic lesions from lesions in the neoterminal ileum. Two further indices, the REMIND score and the POCER index, were recently developed with the same intention. Noninvasive monitoring for recurrence using a method with high negative predictive value has the potential to simplify management algorithms and only perform ileocolonoscopy in a subset of patients. Fecal calprotectin, intestinal ultrasound, and magnetic resonance enterography are all being evaluated for this purpose. The use of infliximab for the prevention of postoperative recurrence is well supported by data, but management decisions are fraught with uncertainty for patients with previous exposure to biologics. Data on the use of ustekinumab and vedolizumab for postoperative CD are emerging, but controlled studies are lacking.

Abbreviated 13C-mixed triglyceride breath test for detection of pancreatic exocrine insufficiency performs equally as standard 5-hour test in patients after gastrectomy performed for gastric cancer.

BACKGROUND: 13C-mixed triglyceride breath test (13C-MTGT) is a non-invasive test for the detection of moderate and severe pancreatic exocrine insufficiency (PEI), but it requires prolonged breath sampling. The aim of this study was to determine the diagnostic power of abbreviated 13C-MTGT in detecting PEI in patients after subtotal and total gastrectomy performed due to gastric cancer. SUBJECTS AND METHODS: This cross-sectional observational study included 3 groups of subjects; healthy controls, patients with subtotal and patients with total gastrectomy. Demographic and clinical data of patients were collected. Stool samples to determine faecal elastase (Fe-1) and chymotrypsin were collected and measured by ELISA. All subjects performed 5-hour 13C-MTGT breath test. The concentration and relative content of 13C in exhaled air was measured by isotope ratio mass spectrometer (IRMS). PEI was confirmed as values of 13C-exhalation < 26.8% after 5 hours. RESULTS: Overall, 65 participants were included into analysis, 22 having PEI (n = 11 after subtotal and n = 11 after total gastrectomy, both performed for gastric cancer). 13C-MTGT breath test showed difference in percent of exhaled 13C between PEI and non-PEI patients already after 60 minutes (p = 0.034). Receiver operating characteristic (ROC) curve analysis showed that cut-off value of 13.74% after 150 minutes is showing equivalent diagnostic power to the longer test with sensitivity and specificity both above 90% for the exclusion of PEI in patients after subtotal and/or total gastrectomy. CONCLUSIONS: In this study abbreviated 13C-MTGT test could be shortened from 5 to 2.5 hours without decrease in its diagnostic accuracy for detection of PEI in patients with subtotal or total gastrectomy performed for gastric cancer. This allows significant time savings in the diagnostics of PEI in this subgroup of patients.

Therapeutic drug monitoring of biologics in inflammatory bowel disease: unmet needs and future perspectives.

Therapeutic drug monitoring (TDM) has emerged as a useful tool for optimising the use of biologics, and in particular anti-tumour necrosis factor (anti-TNF) therapy, in inflammatory bowel disease (IBD). However, challenges remain and are hindering the widespread implementation of TDM in clinical practice. These barriers include identification of the optimal drug concentration to target, the lag time between sampling and results, and the proper interpretation of anti-drug antibody titres among different assays. Solutions to overcome these barriers include the harmonisation of TDM assays and the use of point-of-care testing. Other unmet needs include well designed prospective studies and randomised controlled trials focusing on proactive TDM, particularly during induction therapy. Future studies should also investigate the utility of TDM for biologics other than anti-TNF therapies in both IBD and other immune-mediated inflammatory diseases such as rheumatoid arthritis and psoriasis, and the use of pharmacokinetic modelling dashboards and pharmacogenetics towards individual personalised medicine.

Endoscopic Postoperative Recurrence in Crohn's Disease After Curative Ileocecal Resection with Early Prophylaxis by Anti-TNF, Vedolizumab or Ustekinumab: A Real-World Multicentre European Study.

BACKGROUND: Endoscopic-post-operative-recurrence [ePOR] in Crohn's disease [CD] after ileocecal resection [ICR] is a major concern. We aimed to evaluate the effectiveness of early prophylaxis with biologics and to compare anti-tumour necrosis factor [anti-TNF] therapy to vedolizumab [VDZ] and ustekinumab [UST] in a real-world setting. METHODS: A retrospective multicentre study of CD-adults after curative ICR on early prophylaxis was undertaken. ePOR was defined as a Rutgeerts score [RS] ≥ i2 or colonic-segmental-SES-CD ≥ 6. Multivariable logistic regression was used to evaluate risk factors, and inverse probability treatment weighting [IPTW] was applied to compare the effectiveness between agents. RESULTS: The study included 297 patients (53.9% males, age at diagnosis 24 years [19-32], age at ICR 34 years [26-43], 18.5% smokers, 27.6% biologic-naïve, 65.7% anti-TNF experienced, 28.6% two or more biologics and 17.2% previous surgery). Overall, 224, 39 and 34 patients received anti-TNF, VDZ or UST, respectively. Patients treated with VDZ and UST were more biologic experienced with higher rates of previous surgery. ePOR rates within 1 year were 41.8%. ePOR rates by treatment groups were: anti-TNF 40.2%, VDZ 33% and UST 61.8%. Risk factors for ePOR at 1 year were: past-infliximab (adjusted odds ratio [adj.OR] = 1.73 [95% confidence interval, CI: 1.01-2.97]), past-adalimumab [adj.OR = 2.32 [95% CI: 1.35-4.01] and surgical aspects. After IPTW, the risk of ePOR within 1 year of VDZ vs anti-TNF or UST vs anti-TNF was comparable (OR = 0.55 [95% CI: 0.25-1.19], OR = 1.86 [95% CI: 0.79-4.38]), respectively. CONCLUSION: Prevention of ePOR within 1 year after surgery was successful in ~60% of patients. Patients treated with VDZ or UST consisted of a more refractory group. After controlling for confounders, no differences in ePOR risk were seen between anti-TNF prophylaxis and other groups.

The comparison of the three assays for determination of fecal calprotectin in inflammatory bowel disease.

INTRODUCTION: Fecal calprotectin is a biomarker for monitoring inflammatory bowel disease (IBD) activity. Our aim, therefore, was to evaluate two new assays, the point of care test Quantum Blue and the Liaison Calprotectin with respect to the Calprest, commonly used assay, and to determine their performance for IBD diagnosis. MATERIALS AND METHODS: We included 73 prospective patients with IBD. Fecal calprotectin was measured and analysed with the routine Calprest assay and two recently introduced assays, the Quantum Blue and the Liaison Calprotectin. Furthermore, we compared the results by Bland and Altman analysis, and Passing-Bablok regression. RESULTS: We observed no difference in median calprotectin values obtained by the Calprest (94.6 µg/g, 95%CI 66.5 to 166.1) and Liaison assay (101.0 µg/g, 95%CI 48.1 to 180.1) whereas significantly higher concentrations were obtained with the Quantum Blue assay (240.0 µg/g, 95%CI 119.9 to 353.2). The mean absolute and relative difference between the Calprest and Quantum Blue methods was statistically significant (- 162.3 µg/g and- 143.1%). Mean absolute difference between the Calprest and Liaison calprotectin methods was positive (2.2 µg/g). The agreement between assays revealed that Quantum Blue and Calprest have fair agreement with Kappa coefficient of 0.38 (95%CI 0.26 to 0.51). Liaison Calprotectin and Calprest revealed moderate agreement with a weak Kappa coefficient of 0.47 (95%CI 0.32 to 0.62). CONCLUSION: Clinicians should be aware of these differences between the assays and avoid comparison of their respective results.

Ustekinumab Dosing Individualization in Crohn's Disease Guided by a Population Pharmacokinetic-Pharmacodynamic Model.

Ustekinumab is a monoclonal antibody used in Crohn's disease (CD). Dose optimization in case of non-response and the role of pharmacokinetic-pharmacodynamic (PK-PD) monitoring remain unresolved dilemmas in clinical practice. We aimed to develop a population PK-PD model for ustekinumab in CD and simulate efficacy of alternative dosing regimens. We included 57 patients and recorded their characteristics during 32 weeks after starting with ustekinumab therapy. Serum ustekinumab concentration was prospectively measured and fecal calprotectin (FC) concentration was used to monitor the disease activity. Ustekinumab PK-PD was described by a two-compartment target-mediated drug disposition model linked to an indirect response model. Lower fat-free mass, higher serum albumin, previous non-exposure to biologics, FCGR3A-158 V/V variant and lower C-reactive protein were associated with higher ustekinumab exposure. Model-based simulation suggested that 41.9% of patients receiving standard dosing achieve biochemical remission at week 32. In patients not achieving remission with standard dosing at week 16, transition to 4-weekly subcutaneous maintenance dosing with or without intravenous reinduction resulted in comparably higher remission rates at week 32 (51.1% vs. 49.2%, respectively). Our findings could be used to guide stratified ustekinumab treatment in CD, particularly in patients with unfavorable characteristics, who might benefit from early transition to 4-weekly maintenance dosing.

Ustekinumab concentrations shortly after escalation to monthly dosing may identify endoscopic remission in refractory Crohn's disease.

OBJECTIVES: Some patients with Crohn's disease do not achieve remission with the approved maintenance dosing of ustekinumab every 8 weeks, possibly due to insufficient drug exposure. We aimed to study the exposure-response relationship for endoscopic remission and biomarker normalization with ustekinumab dose escalation to every 4 weeks. METHODS: Out of 135 consecutive patients, 44 with active Crohn's disease despite standard maintenance dosing [at least one of C-reactive protein (CRP) >5 mg/L, fecal calprotectin >100 mg/kg, simple endoscopic score (SES) for Crohn's disease >3] underwent dose escalation to every 4 weeks. Subsequent endoscopic remission (SES-CD ≤3 without ulceration) and biomarker normalization were compared against ustekinumab concentrations. RESULTS: Dose escalation led to endoscopic remission in 28.6% (8/28), CRP normalization 29.2% (7/24) and fecal calprotectin normalization 51.7% (15/29) of patients. Ustekinumab concentrations after escalation were higher in patients with endoscopic remission (6.90 vs. 4.29 mg/L; P = 0.025) and fecal calprotectin normalization (6.65 vs. 3.74 mg/L; P = 0.001). A threshold of 6.00 mg/L identified endoscopic remission [area under the receiver operating curve (AUROC): 0.775; 95% confidence interval (CI), 0.551-0.999), a threshold of 4.40 mg/L (AUROC 0.755; 95% CI, 0.545-0.964) two months after escalation identified patients with fecal calprotectin normalization at the end of follow-up. Concentrations <3.5 mg/L after escalation precluded endoscopic remission or biomarker normalization. CONCLUSION: Endoscopic remission was associated with higher ustekinumab concentrations after dose escalation. Patients with concentrations <3.5 mg/L after dose escalation are unlikely to achieve endoscopic remission or biomarker normalization.