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BACKGROUND: Whether infliximab therapy can be successfully discontinued after patients with Crohn’s disease have attained sustained, clinical, biochemical, and endoscopic remission is unknown. METHODS: We conducted a multicenter, randomized, double-blind, placebo-controlled withdrawal study of infliximab in patients with Crohn’s disease who were in clinical, biochemical, and endoscopic remission after standard infliximab maintenance therapy for at least 1 year. Patients were randomly assigned 1:1 to continue infliximab therapy or to receive matching placebo for 48 weeks. The primary end point was time to relapse. RESULTS: This study randomly assigned 115 patients to either the infliximab-continuation group or to the infliximab-discontinuation group. No relapses were observed among the 59 patients continuing infliximab, whereas 23 of 56 patients discontinuing infliximab experienced relapse. Time to relapse was significantly shorter among patients who discontinued infliximab than among those who continued infliximab (hazard ratio, 0.080; 95% confidence interval [CI], 0.035 to 0.186; P<0.001). At the end of the trial at week 48, relapse-free survival was 100% in the infliximab-continuation group and 51% in the infliximab-discontinuation group. The key secondary end point, time to loss of remission, was significantly shorter among patients discontinuing infliximab therapy than those continuing infliximab (hazard ratio, 0.025; 95% CI, 0.003 to 0.187; P<0.001). No unexpected adverse events were reported. CONCLUSIONS: Discontinuation of infliximab for patients with Crohn’s disease receiving long-term infliximab therapy and in clinical, biochemical, and endoscopic remission leads to a considerable risk of relapse. (Funded by the Nordic Trial Alliance [NordForsk], the Medical Fund of the Danish Regions [Regionernes Medicin og Behandlingspulje], the Danish Colitis-Crohn Association, and the A.P. Moller Foundation; ClinicalTrials.gov number, NCT01817426; EudraCT number, 2012-002702-51.)

Background: Primary infliximab treatment failure is common in patients with inflammatory bowel disease and represents a challenge to clinicians. Treatment options are limited. This study assessed the prognosis, defined as surgery-free survival, in patients with primary infliximab treatment failure as compared to patients without primary failure (initial responders). Furthermore, this study assessed the specter of medical therapies used after primary infliximab treatment failure along with treatment outcomes., Methods: Retrospective, observational, cohort study of patients with inflammatory bowel disease treated with infliximab as first-line anti-tumor necrosis factor treatment at a tertiary center. Primary infliximab treatment failure was defined as no clinical improvement during infliximab induction therapy resulting in discontinuation of infliximab therapy., Results: A total of 560 patients (Crohn's disease n = 353 and ulcerative colitis n = 207) were treated with infliximab. Among these, 81 (15%) had primary infliximab treatment failure after a median of 3 infusions (weeks 0, 2, and 6) (interquartile range 2-4). The median surgery-free survival was 196 days from first infusion. One year after primary infliximab treatment failure, the majority of patients (n = 51, 63%) had inflammatory bowel disease-related surgery (Crohn's disease n = 19, 58%; ulcerative colitis n = 32, 67%; P = 0.49). There was a markedly increased risk of surgery in patients with primary infliximab treatment failure as compared to initial responders: odds ratio 6.3 (3.8-10.6), P < 0.0001. Among 30 patients handled by medical therapies, 16 (53%) still had active disease 1 year after primary infliximab treatment failure., Conclusions: Primary infliximab treatment failure is associated with poor outcome including high risk of surgery or sustained active disease despite medical interventions.

Antibodies (Abs) against infliximab (IFX) increase IFX clearance and can result in treatment failure and acute hypersensitivity reactions. However, interpretation of their clinical value is complicated by individual differences in Ab responses and methods used for quantification. The increase in IFX clearance imposed by anti-IFX Abs has generally been evaluated using a binary classification, i.e., positive or negative. This analysis aimed to investigate if anti-IFX Ab concentrations provide a more adequate prediction of alterations in clearance. Data originated from a clinical trial on Crohn's disease patients with IFX treatment failure. The trial was not originally designed for pharmacokinetic analysis. Therefore, published pharmacokinetic models were utilized as priors to enable covariate investigation. The impact of anti-IFX Abs on clearance was assessed using different mathematical relationships and exploiting information from two different quantification assays, measuring semi-quantitative "total" or "unbound neutralizing" concentrations of anti-IFX Ab, respectively. Inclusion of anti-IFX Ab status/concentration improved the model's performance for all investigated relationships. The anti-IFX Ab concentrations were superior to the binary classifications, indicating that the magnitude of increase in IFX clearance imposed by anti-IFX Abs closely relates to their concentration. Furthermore, total anti-IFX Ab concentrations appeared superior to the unbound neutralizing fraction in identifying high clearance individuals. Simulations showed that even at low concentrations, anti-IFX Abs lead to sub-therapeutic IFX concentrations, supporting a need of treatment interventions in all anti-IFX Ab positive patients. The developed model can serve as a basis for further investigations to refine treatment recommendations for patients with anti-IFX Abs.

Background: Antibodies (Abs) against adalimumab (ADL) have been associated with low ADL levels and treatment failure., Aim: To characterize the temporal characteristics of anti-ADL Ab appearance and possible disappearance, and determine the clinical significance on drug efficacy and disease course., Methods: Cohort study including inflammatory bowel disease patients in whom anti-ADL Abs had been assessed by radioimmunoassay (RIA) and, in case of disappearance, by enzyme immunoassay, and functional reporter gene assay., Results: Anti-ADL Abs were evaluated in 133 serum samples from 72 patients. Seventeen patients (24%) tested positive after median of 194 days, interquartile range of 66 to 361. The proportion with anti-ADL Abs was 22% after 1 year, and 32% from 21 months onwards. Anti-ADL Abs generally persisted at repeat assessments during continued ADL therapy (n=8). Disappearance of anti-ADL Abs during therapy (n=3) was presumably caused by methodological biases due to detection of nonfunctional nonpersistent anti-ADL Abs by RIA, or false-negative measurement at reassessment by RIA and reporter gene assay. Anti-ADL Abs appeared pharmacologically active as judged by a median ADL concentration below limit of detection versus 7.4 μg/mL in anti-ADL Ab-negative samples (P<0.0001). Anti-ADL Abs associated with loss of response (odds ratio estimated 67, P<0.0001), and shorter treatment duration (P<0.0001)., Conclusions: Abs against ADL appear in approximately one fourth of inflammatory bowel disease patients with decreasing frequency over time and usually within 1 year of therapy. Anti-ADL Abs generally persist during continued ADL therapy, and are associated with elimination of drug and treatment failure. Therefore, ADL cessation should be considered when anti-ADL Abs are detected and supported by clinical observations.

Objectives: Implementation of guidelines for prevention of infectious diseases during anti-TNFα therapy in patients with inflammatory bowel disease (IBD) is important but difficult. We investigated whether systematic information to health-care professionals about these guidelines improves patients' adherence., Methods: The study comprised three parts: (1) cross-sectional evaluation of baseline vaccination status in all IBD patients in anti-TNFα therapy (reference group; n=130); (2) prospective interventional study, where health-care professionals received systematic oral and written information about vaccination guidelines at baseline and at 2-month intervals for 6 months, followed by reassessment of vaccination status (intervention group; n=99); (3) cross-sectional evaluation of representative gastroenterologists' knowledge of guidelines (n=53). Outcomes were assessed by validated questionnaires., Results: Patients' adherence to vaccination guidelines increased significantly after a period of systematic information to health-care professionals. Hence, complete adherence increased from 5 to 26%, partial adherence from 38 to 56%, and complete non-adherence decreased from 57 to 18% (P<0.0001). Adherence to all individual vaccinations except human papilloma virus increased significantly (P≤0.0021). Improvement was independent of disease type and anti-TNFα agent. At baseline, only 8% of physicians could identify all elements in the reference guideline. Additional barriers reported by physicians were forgetfulness (32%) and insufficient consultation time (26%). Patient-perceived barriers were costs of vaccinations (35%) and forgetfulness (25%)., Conclusions: Gastroenterologists' limited knowledge of vaccination guidelines during anti-TNFα therapy can be overcome by systematic education of health-care professionals. This inexpensive and easily accessible intervention immediately results in markedly improved patient adherence. Remaining obstacles for adherence comprise high vaccination costs and forgetfulness.

Background: This study assessed the effects of infliximab (IFX) treatment failure on patient-reported outcomes and explored the influence of using personalized treatment in this situation., Methods: Sixty-nine Crohn's disease patients with IFX treatment failure were randomized to an intensified IFX regimen (n = 36) or personalized treatment defined by IFX and anti-IFX antibodies (n = 33). Health-related quality of life evaluated with the Short Inflammatory Bowel Disease Questionnaire (IBDQ) and productivity evaluated with the Work Productivity and Activity Impairment Questionnaire (WPAI:CD) were assessed at treatment failure and after 4, 8, 12 and 20 weeks., Results: Median IBDQ score at manifestation of IFX treatment failure was 40 and improved markedly in responders by 11 at weeks 4 and 8 (p < 0.001) and by 13 at weeks 12 and 20 (p < 0.001). Non-responders improved modestly at weeks 12 and 20 (increase of median 4, p < 0.05). Overall activity impairment was high at IFX failure (median 70%) and decreased substantially in responders (40-50%, p < 0.001) and to a lesser extent in non-responders (15-40%, p < 0.05). In employed patients (55%), absenteeism was negligible during the entire study period. However, median presenteeism was 40% at manifestation of IFX failure and decreased only among responders across time (decrease 10-30%, p < 0.05). Although anti-tumour necrosis factor (TNF) therapy was discontinued in most patients handled by personalized treatment, IBDQ and WPAI:CD scores were similar in these patients compared with patients routinely dose-intensified on IFX., Conclusion: Regaining low disease activity after IFX failure is necessary for minimizing patient impairment and indirect disease-related costs. A personalized treatment strategy does not have a negative influence on patient-reported outcomes., (Copyright © 2015 European Crohn’s and Colitis Organisation (ECCO). Published by Oxford University Press. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Background: Patients with Crohn's disease (CD) have a higher risk of infectious diseases including pneumococcal infections, and the risk increases with immunotherapy. The primary endpoint of this study was to investigate the specific antibody response to two pneumococcal vaccines in CD patients with and without immunosuppressive treatment four weeks post vaccination., Methods: In a randomized trial of the 23-valent pneumococcal polysaccharide vaccine (PPV23) and the 13-valent pneumococcal conjugated vaccine (PCV13), a group of CD patients treated with immunosuppressive drugs (IS) alone or in combination with TNF-α antagonists were compared to a group of CD patients not treated with any of these drugs (untreated). Specific pneumococcal antibody concentrations were measured against 12 serotypes common to the two vaccines before and 4 week after vaccination., Results: PCV13 induced a significantly higher antibody response for one serotype (23F) in IS treated patients and for two serotypes (9V and 23F) in untreated patients compared to CD patients vaccinated with PPV23. Untreated PPV23 recipients had higher responses for serotypes 9V and 18C compared to IS+TNF-α treated PPV23 recipients. Comparison between treatment groups showed that immunosuppressive treatment impaired the antibody response to both vaccines and that TNF-a treatment further conveyed additional impairment of the response., Conclusion: PCV13 induces higher antibody response for some serotypes compared to PPV23. In addition, CD patients treated with immunosuppressive drugs alone or in combination with TNF-α antagonists had an impaired antibody response to both PPV23 and PCV13 compared to patients not receiving any of these treatments. The study has been registered in the European Clinical Trials Database (EudraCT, record no 2012-002867-86) and ClinicalTrials.gov (record no. NCT01947010)., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Background: In Crohn's disease patients failing infliximab therapy, interventions defined by an algorithm based on infliximab and anti-infliximab antibody measurements have proven more cost-effective than intensifying the infliximab regimen., Aim: This study investigated long-term economic outcomes at the week 20 follow-up study visit and after 1 year. Clinical outcomes were assessed at week 20., Methods: Follow-up from a 12-week, single-blind, clinical trial where patients with infliximab treatment failure were randomized to infliximab intensification (5 mg/kg every 4 weeks) (n = 36), or algorithm-defined interventions (n = 33). Accumulated costs, expressed as mean costs per patient, were based on the Danish National Patient Registry., Results: At the scheduled week 20 follow-up study visit, response and remission rates were similar in all study subpopulations between patients treated by the algorithm or by infliximab intensification. However, the sum of healthcare costs related to Crohn's disease was substantially lower (31 %) for patients randomized to algorithm-based interventions than infliximab intensification in the intention-to-treat population: $11,940 versus $17,236; p = 0.005. For per-protocol patients (n = 55), costs at the week 20 follow-up visit were even lower (49 %) in the algorithm group: $8,742 versus $17,236; p = 0.002. Figures were similar for patients having completed the 12-week trial as per protocol (50 % reduction in costs) (n = 45). Among patients continuing the allocated study intervention throughout the entire 20-week follow-up period (n = 29), costs were reduced by 60 % in algorithm-treated patients: $7,056 versus $17,776; p < 0.001. Cost-reduction percentages remained stable throughout one year., Conclusion: Economic benefit of algorithm-based interventions at infliximab failure is maintained throughout 1 year.

Background and Aims: Intensification of the infliximab (IFX) regimen is recommended if the treatment effect is inadequate. However, the rationale for this is not well defined as the underlying mechanisms vary. The aim of this study was to explore the association between changes in serum IFX and anti-IFX antibodies (Abs) after IFX intensification and clinical outcomes., Methods: We performed a post hoc analysis of a randomized clinical trial including 42 Crohn's disease patients with IFX treatment failure, all treated with an intensified IFX regimen (5mg/kg every 4 week) for 12 weeks. Trough serum IFX and anti-IFX Ab concentrations were measured by a homogeneous mobility shift binding assay (HMSA) and a functional cell-based reporter gene assay (RGA) at treatment failure and the end of the trial., Results: Twenty-one patients (50%) regained clinical response on the intensified IFX regimen. The increase in serum trough levels of IFX during treatment intensification was higher among responders than non-responders (RGA, 8.8 versus 3.0 μg/mL, p = 0.035; HMSA, 9.9 versus 4.7 μg/mL, p = 0.040), and differentiated patients by clinical outcome (RGA, area under receiver operating characteristic curve [AUC] 0.75 [0.53-0.97], p = 0.035; HMSA, AUC 0.74 [0.53-0.95], p = 0.042). All responders exhibited an IFX increase ≥2.6 μg/mL (sensitivity 100%, specificity 50%). Anti-IFX Abs detected by HMSA in 13 patients (32%) were often non-functional and became undetectable during IFX intensification. However, even functional anti-IFX Abs detected by RGA in six patients (15%) became undetectable., Conclusion: Increase in IFX levels following treatment intensification was associated with improved clinical outcomes, indicating insufficient drug levels in a subgroup of patients. Anti-IFX Abs may become undetectable during treatment intensification, suggesting lowered production or the formation of immune complexes., (Copyright © 2015 European Crohn’s and Colitis Organisation (ECCO). Published by Oxford University Press. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

The risk of colorectal cancer (CRC) and dysplasia in patients with inflammatory bowel disease (IBD) has been highly debated as risk estimates from different studies vary greatly. The present national Danish guideline on colonoscopy surveillance for dysplasia and colorectal cancer in patients with IBD is based on a thorough review of existing literature with particular focus on recent studies from Denmark revealing a lower risk of CRC than previously assumed. The overall risk of CRC in the Danish IBD population does not appear to be different from that of the background population; however, in some subgroups of patients the risk is increased. These subgroups of patients, who should be offered colonoscopy surveillance, include patients with ulcerative colitis having extensive disease and a long disease duration (10-13 years); early age at onset (less than 19 years of age) of ulcerative colitis; and patients with ulcerative colitis as well as Crohn's disease with a concomitant diagnosis of primary sclerosing cholangitis. A colonoscopy surveillance program is recommended in these subgroups with intervals ranging from every 3-6 months to every 5 years, using chromoendoscopy with targeted biopsies of the lesion and adjacent mucosa, instead of conventional colonoscopy with random biopsies. Preferably, the colonoscopy should be performed during clinical remission. If a lesion is detected the endoscopical resectability together with the pathology of the lesion and the adjacent mucosa determine how the lesion should be treated.

Introduction: Infliximab (IFX), a monoclonal chimeric antibody against tumour necrosis factor (TNF) α, is effective for induction and maintenance of remission in moderate to severe Crohn's disease. Discontinuation of IFX maintenance therapy in patients in remission should be considered in order to reduce the potential long-term side effects and lower costs., Methods and Analysis: This is a prospective, double-blind, randomised, placebo-controlled, multicentre study of patients with luminal Crohn's disease who have been treated with IFX for at least 1 year and are in sustained complete clinical, biochemical and endoscopic remission (ie, Crohn's Disease Activity Index (CDAI) score <150, complete mucosal healing and biochemical markers of inflammation within the normal range). These patients are randomised to receive placebo infusions or continue IFX maintenance therapy. The primary end point is the proportion of patients in maintained remission after 48 weeks (def. CDAI <150)., Ethics and Dissemination: It is estimated that the knowledge gained about how to optimally handle patients with Crohn's disease in complete long-term sustained remission on IFX is proportionate to the risks and inconveniences related to participation in this study. Prolonged exposure to IFX may cause severe side effects and increased risk of malignancies. Conversely, IFX discontinuation should not unnecessarily create a high risk of relapse. Thus, empirical evidence is needed concerning the safety of discontinuing IFX once a patient exhibits sustained remission. Study results will be published in an English language scientific medical journal. The study is approved by the Danish Medicines Agency (EudraCT-number: 2012-002702-51) and the Regional Ethics Committee of Region Hovedstaden Denmark (Approval-number: H-4-2012-099). The project is reported to the Danish Data Protection Agency (ID-number: 2007-58-0015/HEH.750.89-27), registered at Clinicaltrials.gov, and monitored by independent GCP units for the University of Copenhagen, Odense and Aarhus. The current approved protocol is V.3.2, dated 1 June 2014., Trial Registration Number: http://clinicaltrials.gov/show/NCT01817426., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.)

Objectives: Cost-effective guidance of therapeutic strategy in Crohn's disease patients with secondary infliximab (IFX) treatment failure may be achieved by serum IFX and anti-IFX antibody (Ab) measurements by radioimmunoassay (RIA). This study investigated implications of using other techniques for this purpose., Methods: This is a post hoc analysis of randomized clinical trial including 66 Crohn's disease patients with IFX failure in whom IFX and anti-IFX Ab measurements by RIA had been used for therapeutic guidance. Samples were additionally assessed by enzyme-linked immunosorbent assay (ELISA), homogeneous mobility shift assay (HMSA), and functional cell-based reporter gene assay (RGA)., Results: IFX detection was comparable between assays (82% RIA, 76% ELISA, 88% HMSA, and 74% RGA), and it correlated significantly (Pearson's r=0.91-0.97, P<0.0001). However, IFX concentrations varied systematically between all pair of assays except RIA-RGA. Anti-IFX Ab detection was variable (27% RIA, 9% ELISA, 33% HMSA, and 11% RGA), but correlated significantly (Pearson's r=0.77-0.96; P<0.0001). Anti-IFX Abs detected by RIA and HMSA were often from sera without drug-neutralizing activity (RGA). Assays agreed on classification of underlying mechanism for treatment failure in most cases (79-94%). The majority (74-88%) failed IFX owing to pharmacodynamic problems, or had noninflammatory pathophysiology for symptoms resembling relapse. Applied threshold for therapeutic vs. subtherapeutic IFX level influenced classifications. The four different assays did not differ in terms of the ability to predict response to interventions defined by the algorithm., Conclusions: Despite variable analytical properties, common assays result in similar classifications and interventions in patients with IFX treatment failure, and with comparable clinical outcomes. Implications are, however, profound for the minority classified differently.

Objective: Although the reasons for secondary loss of response to infliximab (IFX) maintenance therapy in Crohn's disease vary, dose intensification is usually recommended. This study investigated the cost-effectiveness of interventions defined by an algorithm designed to identify specific reasons for therapeutic failure., Design: Randomised, controlled, single-blind, multicentre study. 69 patients with secondary IFX failure were randomised to IFX dose intensification (5 mg/kg every 4 weeks) (n=36) or interventions based on serum IFX and IFX antibody levels using the proposed algorithm (n=33). Predefined co-primary end points at week 12 were proportion of patients responding (Crohn's Disease Activity Index (CDAI) decrease ≥ 70, or ≥ 50% reduction in active fistulas) and accumulated costs related to treatment of Crohn's disease, expressed as mean cost per patient, based on the Danish National Patient Registry for all hospitalisation and outpatient costs in the Danish healthcare sector., Results: Costs for intention-to-treat patients were substantially lower (34%) for those treated in accordance with the algorithm than by IFX dose intensification: € 6038 vs € 9178, p<0.001. However, disease control, as judged by response rates, was similar: 58% and 53%, respectively, p=0.81; difference 5% (-19% to 28%). For per-protocol patients, treatment costs were even lower (56%) in the algorithm-treated group (€ 4062 vs € 9178, p<0.001) and with similar response rates (47% vs 53%, p=0.78; difference -5% (-33% to 22%))., Conclusions: Treatment of secondary IFX failure using an algorithm based on combined IFX and IFX antibody measurements significantly reduces average treatment costs per patient compared with routine IFX dose escalation and without any apparent negative effect on clinical efficacy., Trial Registration No: NCT00851565.

Background: The aim of the study was to investigate variations in anti-infliximab (IFX) antibody (Ab) levels and clinical implications thereof in patients with inflammatory bowel disease (IBD)., Methods: A retrospective, explorative, single-center study of patients with IBD who developed anti-IFX Ab and in whom anti-IFX Ab were reassessed., Results: IFX was administered to 316 patients; anti-IFX Ab was determined in 180 patients and detected in 83 (46%). During ongoing IFX maintenance therapy, anti-IFX Ab disappeared at later reassessment in two-thirds of patients with clinical response after median 4 (3-5) infusions. In contrast, anti-IFX Ab persisted in all patients without clinical response. Anti-IFX Ab appeared pharmacologically active, as IFX levels were high when anti-IFX Ab disappeared (median 3.7 μg/mL, interquartile range [IQR] 2.8-5.5), while undetectable or low when anti-IFX Ab persisted (median 0 μg/mL, IQR 0-0). In 56 patients, anti-IFX Ab were assessed after IFX discontinuation. The proportion of patients with anti-IFX Ab gradually declined over time, with a few patients having anti-IFX Ab up to about 4 years after initial assessment. No variables were associated with anti-IFX Ab disappearance in multivariate analysis., Conclusions: Discontinuation of IFX is advisable in patients with inadequate response and repeat positive anti-IFX Ab measurements. Anti-IFX Ab can persist for years after discontinuation, which could impact efficacy and safety at retreatment. Continued IFX treatment may, however, be considered in patients with clinical response and a single positive anti-IFX Ab measurement, as anti-IFX Ab disappears in two-thirds of these during continued treatment., (Copyright © 2012 Crohn's & Colitis Foundation of America, Inc.)

Background: Single nucleotide polymorphisms (SNPs) in TNF receptor superfamily (TNFRSF) 1A and 1B, and Fas ligand (FASLG) genes, have been associated with responsiveness to infliximab (IFX) in Crohn's disease., Aim: To investigate if SNPs in TNFRSF1A and 1B, and FAS (TNFRSF6) and FASLG (TNFSF6), associated with short- or long-term clinical and biological efficacy and with acute severe infusion reactions., Methods: Observational, retrospective and explorative cohort study of IFX-treated Caucasian patients with Crohn's disease classified as primary nonresponders (n = 21), response failures on maintenance therapy (n = 37), maintained remission (n = 47) and occurrence of acute severe infusion reactions (n = 20)., Results: During IFX maintenance therapy, minor allele carriage of TNFRSF1B, rs976881 is associated with loss of response [OR 3.3 (1.2-9.1), P = 0.014]. Minor allele homozygosity increased the risk substantially (OR estimated 19, P = 0.006), and furthermore associated with a mean CRP increase of 17 mg/L as compared to a mean decrease of 17 mg/L in all others (P = 0.036). In contrast, minor allele carriage of TNFRSF1B, rs1061622 is associated with beneficial response to IFX induction [OR 4.2 (1.2-18.2), P = 0.014], and with persistence of remission during maintenance therapy [OR 5.5 (1.5-25.5), P = 0.007]. Carriage of the minor allele of FASLG, rs76110 increased risk of severe infusion reactions [OR 4.0 (1.1-22.4), P = 0.041]; minor allele carriage of TNFRSF1B, rs652625 decreased the risk (OR estimated 0.2, P = 0.043 )., Conclusions: The TNFRSF1B polymorphisms may contribute to predict efficacy of infliximab. Moreover, FASLG and TNFRSF1B polymorphisms may confer genetic susceptibility to severe infusion reactions. These findings could potentially aid clinical decisions if confirmed in larger studies., (© 2012 Blackwell Publishing Ltd.)

A 61 year old woman with active luminal Crohn's disease was successfully treated with infliximab induction therapy followed by 5 infusions every 8 weeks. However, symptoms returned in the weeks preceding the 7th and 8th infusions. The 9th infusion was therefore given only 4 weeks after the 8th infusion, but an acute severe anaphylactoid reaction occurred immediately after start of the infusion. Anti-infliximab IgG antibody concentration was high (100 U/ml) prior to the 8th infusion and up to 1 year after infliximab discontinuation (81 U/ml). Anti-infliximab IgE antibodies were not found, and the anti-infliximab antibodies did not cross react with adalimumab. One week after the anaphylactoid reaction to infliximab, adalimumab therapy was initiated. Twelve days after the first adalimumab administration (80 mg), a delayed hypersensitivity reaction occurred. This was likely caused by rapidly generated anti-adalimumab IgG antibodies (45 U/ml), as these antibodies appeared to be specific for adalimumab in that infliximab failed to compete with adalimumab/anti-adalimumab antibody binding ex vivo. In conclusion, immunogenicity to infliximab and adalimumab may be associated with both acute anaphylactoid reactions and delayed hypersensitivity reactions. Reactions may be precipitated by newly induced specific anti-drug antibodies rather than by cross-reactivity of previously generated antibodies., (Copyright © 2011 European Crohn's and Colitis Organisation. Published by Elsevier B.V. All rights reserved.)

Background: Infliximab (IFX) elicits acute severe infusion reactions in about 5% of patients with inflammatory bowel disease (IBD)., Aim: To investigate the role of anti-IFX antibodies (Ab) and other risk factors., Methods: The study included all IBD patients treated with IFX at a Danish university hospital until 2010 either continuously (IFX every 4-12 weeks) or episodically (reinitiation after >12 weeks). Anti-IFX Ab were measured using radioimmunoassay., Results: Twenty-five (8%) of 315 patients experienced acute severe infusion reactions. Univariate analysis showed that patients who reacted were younger at the time of diagnosis (19 vs. 26 years, P=0.013) and at first IFX infusion (28 vs. 35 years, P=0.012). Furthermore, they more often received episodic therapy (72% vs. 31%, P<0.001) and logistic regression revealed this as the only significant predictor of reactions (OR 5 [2-13]; P<0.001). IFX reinitiation after 6 months intermission further increased the risk (OR 8 [3-20], P<0.001). Most reactions (n=14, 88%) occurred at 2nd infusion in the 2nd treatment series (P=0.006). Anti-IFX IgG Ab were highly positive in 19 of 20 patients (95%) shortly after the reactions (median 84 U/mL). Anti-IFX IgG Ab measured prior to the retreatment series were negative in 7 of 11 patients tested (64%). Anti-IFX IgE Ab were negative in all patients with reactions., Conclusions: Acute severe infusion reactions were strongly associated with development of anti-IFX IgG Ab, but not with anti-IFX IgE Ab. The risk was particularly high at the 2nd infusion in retreatment series. Negative anti-IFX Ab before reinitiation did not rule out reactions., (© 2011 Blackwell Publishing Ltd.)

Introduction: Reasons for infliximab failure in Crohn's disease and ulcerative colitis are debated. Serum levels of infliximab and anti-infliximab antibodies have been associated with loss of response. We aimed at determining cut-off levels for infliximab and anti-infliximab antibody concentrations associated with clinical response to infliximab maintenance therapy., Methods: Patients with inflammatory bowel disease (n = 106) were retrospectively classified as having maintained response or loss of response to infliximab maintenance therapy. Trough concentrations were measured by fluid-phase radioimmunoassays., Results: Infliximab levels were significantly lower, and anti-infliximab antibody levels significantly higher, in Crohn's disease patients with loss of response (median infliximab 0 μg/ml, median anti-infliximab antibodies 35 U/ml) compared to patients with maintained response (median infliximab 2.8 μg/ml, median anti-infliximab antibodies 0 U/ml; p < 0.0001). Receiver operating characteristic (ROC) analysis identified optimal cut-off values: infliximab <0.5 μg/ml, which was associated with loss of response with sensitivity 86% [64-97] and specificity 85% [72-94]; and anti-infliximab antibodies ≥10 U/ml yielding a sensitivity of 81% [61-93] and specificity 90% [79-96]. Combined measurements of infliximab and anti-infliximab antibodies using these cut-off values had higher accuracy yielding a sensitivity of 81% [57-94] and specificity 94% [82-98]. Similar pattern was observed in a smaller cohort of patients with ulcerative colitis., Conclusions: Combined measurements of infliximab and anti-infliximab antibodies using cut-off levels provided high accuracy for discriminating between clinical response types to infliximab maintenance therapy. Cut-off levels are considered a prerequisite to further investigations of clinical usefulness of measurements of infliximab and anti-infliximab antibodies in patients failing infliximab therapy.

Background: Treatment options for fistulizing Crohn's disease (CD) are limited., Aim: To examine whether fistula closure is maintained at week 26 following treatment with certolizumab pegol., Methods: Patients with draining fistulas at baseline from PRECiSE 2 (n = 108) received open-label induction with certolizumab pegol 400 mg at weeks 0 (baseline), 2 and 4. Response was defined as ≥100-point decrease from baseline in the Crohn's Disease Activity Index. Nonresponders (50/108) were excluded. At week 6, responders with draining fistulas (N = 58) were randomised to certolizumab pegol 400 mg (n = 28) or placebo (n = 30) every 4 weeks across weeks 8-24. Fistula closure was evaluated throughout the study, with a final assessment at week 26., Results: The majority of patients (55/58) had perianal fistula. At week 26, 36% of patients in the certolizumab pegol group had 100% fistula closure compared with 17% of patients receiving placebo (P = 0.038). Protocol-defined fistula closure (≥50% closure at two consecutive post-baseline visits ≥3 weeks apart) was not statistically significant (P = 0.069) with 54% and 43% of patients treated with certolizumab pegol and placebo achieving this end point, respectively., Conclusion: Continuous treatment with certolizumab pegol improves the likelihood of sustained perianal fistula closure compared with placebo., (© 2010 Blackwell Publishing Ltd.)

Background & Aims: The safety and efficacy of maintenance therapy with the anti-tumor necrosis factor certolizumab pegol has not been reported beyond 6 months. We assessed the long-term efficacy, safety, and immunogenicity of continuous versus interrupted maintenance therapy with subcutaneous certolizumab pegol in patients with Crohn's disease., Methods: Patients who responded to induction therapy at week 6 of the PEGylated Antibody Fragment Evaluation in Crohn's Disease: Safety and Efficacy (PRECiSE) 2 trial were assigned randomly to groups given certolizumab pegol (continuous) or placebo (drug-interruption) during weeks 6 to 26. Patients who completed PRECiSE 2 were eligible to enter PRECiSE 3, an ongoing, prospective, open-label extension trial in which patients have received certolizumab pegol (400 mg) every 4 weeks for 54 weeks to date, and were not offered the option to increase their dose. Disease activity was measured by the Harvey-Bradshaw Index., Results: Harvey-Bradshaw Index responses at week 26 for the continuous and drug-interruption groups were 56.3% and 37.6%, respectively; corresponding remission rates were 47.9% and 32.4%, respectively. Of patients responding at week 26, response rates at week 80 after the start of PRECiSE 2 in the continuous and drug-interruption groups were 66.1% and 63.3%, respectively; among patients in remission at week 26, week 80 remission rates were 62.1% and 63.2%, respectively. More patients in the drug-interruption group developed antibodies against certolizumab pegol (and had lower plasma concentrations of certolizumab pegol) than the continuously treated group., Conclusions: Certolizumab pegol effectively maintains remission of Crohn's disease for up to 18 months. Continuous therapy is more effective than interrupted therapy., (Copyright (c) 2010 AGA Institute. Published by Elsevier Inc. All rights reserved.)

Treatment of inflammatory bowel disease (IBD) with antibodies against tumour necrosis factor-alpha (TNF) is effective. Not all patients respond, however, and the effect wears off in a considerable fraction of initial responders over time. Individual differences in bioavailability, pharmacokinetics and immunogenicity are now recognized as essential problems in the use of biologicals, and blood measurements of functional anti-TNF antibodies and antibodies against anti-TNF drugs with robust and clinically relevant methods may optimize treatment of IBD through individualized therapeutic regimens.

Crohn's disease (CD) and ulcerative colitis (UC) are chronic inflammatory bowel diseases that have a remitting, relapsing nature. During relapse, they are treated with drugs and surgery. The present study was based on individual data from patients diagnosed with CD or UC at Herlev University Hospital, Copenhagen, Denmark, during 1991 to 1993. The data were aggregated over calendar years; for each year, the number of relapses and the number of surgical operations were recorded. Our aim was to estimate Markov models for disease activity in CD and UC, in terms of relapse and remission, with a cycle length of 1 month. The purpose of these models was to enable evaluation of interventions that would shorten relapses or postpone future relapses. An exact maximum likelihood estimator was developed that disaggregates the yearly observations into monthly transition probabilities between remission and relapse. These probabilities were allowed to be dependent on the time since start of relapse and on the time since start of remission, respectively. The estimator, initially slow, was successfully optimized to shorten the execution time. The estimated disease activity model for CD fits well to observed data and has good face validity. The disease activity model is less suitable for UC due to its transient nature through the presence of curative surgery.

The transmural inflammation characteristic of Crohn's disease predisposes patients to the formation of fistulas. Up to 50% of patients with Crohn's disease are affected by fistulas, which is a major problem given the considerable morbidity associated with this complication. Appropriate treatment of fistulas requires knowledge of specific pharmacological and surgical therapies. Treatment options depend on the severity of symptoms, fistula location, the number and complexity of fistula tracts, and the presence of rectal complications. Internal fistulas, such as ileoileal or ileocecal fistulas, are mostly asymptomatic and do not require intervention. By contrast, perianal fistulas can be painful and abscesses may develop that require surgical drainage with or without seton placement, transient ileostomy, or in severe cases, proctectomy. This Review describes the epidemiology and pathology of fistulizing Crohn's disease. Particular focus is given to external and perianal fistulas, for which treatment options are well established. Available therapeutic options, including novel therapies, are discussed. Wherever possible, practical and evidence-based treatment regimens for Crohn's disease-associated fistulas are provided.

Antibody constructs targeting tumour necrosis factor-alpha (TNF) have become important in the management of several chronic immunoinflammatory diseases. Four recombinant anti-TNF drugs are currently approved for clinical use in patients with various chronic inflammatory diseases, three of which are effective in chronic inflammatory bowel disease. These proteins can dramatically lower disease activity and, in some patients, induce remission. Unfortunately, however, not all patients respond favourably to anti-TNF antibodies. For example, patients suffering from Crohn's disease do not benefit from etanercept, and some patients treated with the other anti-TNF constructs either do not respond at all (primary response failure), or they respond initially but have later relapses (secondary response failure) despite increased dosage and/or more frequent administration of the drugs. The reason(s) for these response failures are not clear but inter-individual and even intra-individual differences in bioavailability and pharmacokinetics may contribute. Furthermore, immunogenicity of the drugs, causing patients to develop anti-drug antibodies (ADAs), contributes to treatment failure. Monitoring patients for circulating levels of functional anti-TNF drugs and ADAs is therefore warranted so that treatment can be tailored to the individual patient (individual medicine or personal medicine) in order that effective and economical long-term therapy can be given with minimal risks to the patients.

Background: It remains uncertain whether the increasing incidence of inflammatory bowel disease (IBD) during the last decades has been accompanied by an alteration in the presentation, course, and prognosis of the disease. To answer this question, 3 consecutive population-based IBD cohorts from Copenhagen, Denmark (1962-2005), were assessed and evaluated., Methods: Phenotype, initial disease course, use of medications, cumulative surgery rate, standardized incidence ratio of colorectal cancer (CRC), and standardized mortality ratio (SMR) were compared in the 3 cohorts, which had a total of 641 patients with Crohn's disease (CD) and 1575 patients with ulcerative colitis (UC)., Results: From 1962 to 2005, the proportion of IBD patients suffering from CD increased (P < 0.001), time from onset of symptoms to diagnosis of CD decreased (P = 0.001), and median age at diagnosis of UC increased (P < 0.01). The prevalence of upper gastrointestinal involvement and pure colonic CD varied significantly between cohorts. UC patients diagnosed in the 1990s had a higher prevalence of proctitis, received more medications, and had a milder initial disease course than did previous patients. The surgery rate decreased significantly in CD but not in UC. The risk of CRC in IBD was close to expected over the entire period, whereas the mortality of patients with CD increased (overall SMR, 1.31; 95% CI, 1.07-1.60)., Conclusions: Despite variations in the presentation and initial course of IBD during the last 5 decades, its long-term prognosis remained fairly stable. Treatment of IBD changed recently, and future studies should address the effect of these changes on long-term prognosis.

Objective: Selective leukocyte apheresis is a new type of non-pharmacological treatment for patients with active ulcerative colitis and Crohn's disease. Preliminary data have indicated that this type of therapy is safe and efficacious, and large sham-controlled studies are currently in progress. In Scandinavia, a substantial number of patients with chronic inflammatory bowel disease have already received leukocyte apheresis on a compassionate use basis and the aim of this study was to report the clinical outcome and adverse events in the first patients treated., Material and Methods: Clinical details of the first consecutive 100 patients with inflammatory bowel disease treated with granulocyte, monocyte/macrophage (Adacolumn) apheresis in Scandinavia were prospectively registered. Median length of follow-up was 17 months, (range 5-30)., Results: The study population comprised 52 patients with ulcerative colitis, 44 patients with Crohn's disease and 4 patients with indeterminate colitis. In 97 patients the indication for Adacolumn treatment was steroid-refractory or steroid-dependent disease. Clinical remission was attained in 48% of the patients with ulcerative colitis, and an additional 27% had a clinical response to the apheresis treatment. The corresponding figures for patients with Crohn's disease were 41% and 23%, respectively. Complete steroid withdrawal was achieved in 27 out of the 50 patients taking corticosteroids at baseline. Adverse events were reported in 15 patients and headache was most frequently reported (n=7)., Conclusions: Granulocyte, monocyte/macrophage apheresis treatment seems to be a valuable adjuvant therapy in selected patients with refractory inflammatory bowel disease. The risk for toxicity or severe adverse events appears to be low.

Background & Aims: To investigate the efficacy and safety of certolizumab pegol (a polyethylene-glycolated Fab' fragment of anti-tumor necrosis factor, CDP870) in Crohn's disease., Methods: In a placebo-controlled, phase II study, 292 patients with moderate to severe Crohn's disease received subcutaneous certolizumab 100, 200, or 400 mg or placebo at weeks 0, 4, and 8. The primary end point was the percentage of patients with a clinical response at week 12 (a Crohn's Disease Activity Index decrease of > or = 100 points or remission [Crohn's Disease Activity Index < or = 150 points]) in the intent-to-treat population., Results: All certolizumab doses produced significant clinical benefit over placebo at week 2 (placebo, 15.1%; certolizumab 100 mg, 29.7% [P = .033]; 200 mg, 30.6% [P = .026]; 400 mg, 33.3% [P = .010]). At all time points, the clinical response rates were highest for certolizumab 400 mg, greatest at week 10 (certolizumab 400 mg, 52.8%; placebo, 30.1%; P = .006) but not significant at week 12 (certolizumab 400 mg, 44.4%; placebo, 35.6%; P = .278). Patients with baseline C-reactive protein levels of 10 mg/L or greater (n = 119) showed clearer separation between active treatment and placebo (week 12 clinical response: certolizumab 400 mg, 53.1%; placebo, 17.9%; P = .005; post hoc analysis) owing to a lower placebo response rate than patients with C-reactive protein levels of less than 10 mg/L. Adverse events were similar among groups., Conclusions: Certolizumab 400 mg may be effective and is well tolerated in patients with active Crohn's disease. High placebo response rates in the large patient subgroup with low C-reactive protein levels may have obscured statistical separation between certolizumab and placebo. Ongoing phase III trials are necessary to establish the clinical efficacy of certolizumab.

Chronic inflammatory bowel diseases (i.e., ulcerative colitis and Crohn's disease) are syndromes in which standardized criteria are necessary in the diagnostic process. The present review is based on the diagnostic criteria used at our institution. We base the diagnosis of ulcerative colitis and Crohn's disease on combined information from the patient history, and radiological, endoscopic and histological findings after exclusion of neoplastic and infectious disease. The patient history must include precise information on the nature and duration of symptoms as well as the presence of relevant influential factors such as travel activity, drug intake and sexual habits. In immunocompromised patients extensive microbiological investigations are required to exclude infection. Typical radiological and colonoscopic findings in ulcerative colitis are mucosal inflammatory changes extending circumferentially and continuously from the rectum and proximally in the colon. In contrast, Crohn's disease is most frequently located in the small bowel and in case of colonic involvement, the rectum is often spared. The best predictors of Crohn's disease are discontinuous lesions, cobblestones and apthous ulceration. Histological changes such as abnormal mucosal architecture and lamina propria cellularity, neutrophil polymorph infiltration and epithelial cell abnormality are useful and reproducible features in the evaluation of colorectal biopsy specimens. The inflammatory bowel diseases, ulcerative colitis and Crohn's disease, continue to be etiological and diagnostic challenges. Increased use of standardized criteria and diagnostic algorithms are essential instruments to improve the overall quality of the management of patients with these diseases.

The effect of glucagon, dibutyrylic cyclic AMP and theophylline on bile production and liver metabolism was studied in fasting, chloralose anesthetized cats. After 45 min infusion of glucagon (0.1 mug/kg/min) total bile flow started to increase and finally reached a level 32% above control bile flow. The rise in flow was accompanied by a parallel increase in the biliary clearance of erythritol and the rate of biliary excretion of inorganic ions, whereas the bile acid excretion remained constant. Glucagon therefore appears to stimulate selectively the bile acid-independent canalicular production of bile. In contrast to the delayed action on bile production, glucagon caused an immediate change in liver metabolism as judged from the elimination rate of ethanol and the rise in plasma glucose concentration. Dibutyrylic cyclic AMP or theorphylline also caused similar immediate changes in liver metabolism but neither substance influenced bile production or the biliary excretion of electrolytes or bile acids. It thus appears that glucagon choleresis in the cat is either independent of cAMP release or that an increase in intracellular cAMP is not in itself sufficient to influence bile secretion. The results also seem to exclude that an increase in insulin production induced by hyperglycemia, or hemodynamic changes in the liver, can explain glucagon choleresis.