Deep Remission at 1 Year Prevents Progression of Early Crohn's Disease.

BACKGROUND & AIMS: We investigated the effects of inducing deep remission in patients with early Crohn's disease (CD). METHODS: We collected follow-up data from 122 patients (mean age, 31.2 ± 11.3 y) with early, moderate to severe CD (median duration, 0.2 years; interquartile range, 0.1-0.5) who participated in the Effect of Tight Control Management on CD (CALM) study, at 31 sites, representing 50% of the original CALM patient population. Fifty percent of patients (n = 61) were randomly assigned to a tight control strategy (increased therapy based on fecal level of calprotectin, serum level of C-reactive protein, and symptoms), and 50% were assigned to conventional management. We categorized patients as those who were vs were not in deep remission (CD endoscopic index of severity scores below 4, with no deep ulcerations or steroid treatment, for 8 or more weeks) at the end of the follow-up period (median, 3.02 years; range, 0.05-6.26 years). The primary outcome was a composite of major adverse outcomes that indicate CD progression during the follow-up period: new internal fistulas or abscesses, strictures, perianal fistulas or abscesses, or hospitalization or surgery for CD. Kaplan-Meier and penalized Cox regression with bootstrapping were used to compare composite rates between patients who achieved or did not achieve remission at the end of the follow-up period. RESULTS: Major adverse outcomes were reported for 34 patients (27.9%) during the follow-up period. Significantly fewer patients in deep remission at the end of the CALM study had major adverse outcomes during the follow-up period (P = .01). When we adjusted for potential confounders, deep remission (adjusted hazard ratio, 0.19; 95% confidence interval, 0.07-0.31) was significantly associated with a lower risk of major adverse outcome. CONCLUSIONS: In an analysis of follow-up data from the CALM study, we associated induction of deep remission in early, moderate to severe CD with decreased risk of disease progression over a median time of 3 years, regardless of tight control or conventional management strategy.

Systematic Review and External Validation of Prediction Models Based on Symptoms and Biomarkers for Identifying Endoscopic Activity in Crohn's Disease.

BACKGROUND & AIMS: Endoscopic healing, an important target of treatment for Crohn's disease (CD), requires ileocolonoscopy, which is costly and burdensome. We investigated whether published noninvasive models (based on symptoms and biomarkers) to evaluate CD activity have sufficient accuracy to replace ileocolonoscopy. METHODS: We performed a systematic review of published noninvasive diagnostic models to evaluate CD activity that used endoscopic features of activity (endoscopic activity) or healing as the reference standard. We externally validated these models for the outcome endoscopic activity (CD endoscopic index of severity scores, ≥3) using data from the a randomized controlled trial investigating tailored treatment with infliximab for active luminal Crohn's disease (TAILORIX) study (346 ileocolonoscopies in 155 patients) and the Utrecht Activity Index (UAI) study (93 ileocolonoscopies in 82 patients). We calculated the area under the receiver operating characteristic curves (AUROCs) for the models using data from these studies, and compared the performance of these models against measurements of fecal calprotectin (FC) and C-reactive protein (CRP). RESULTS: We screened 5303 articles and identified 27 models (from 21 studies) for our analysis. Seven models could be validated externally; in the TAILORIX data set, these models identified patients with endoscopic activity with AUROC values ranging from 0.61 (95% CI, 0.51-0.70) to 0.81 (95% CI, 0.76-0.86). In this data set, the AUROC value for FC concentration was 0.79 (95% CI, 0.74-0.85) and the AUROC value for CRP level was 0.72 (95% CI, 0.66-0.77). The AUROC values for the validation in the UAI data set were similar. In the TAILORIX and/or UAI data set, 4 of the 7 models, as well as the FC and CRP assays, were able to identify patients with endoscopic activity with positive predictive values of 90% or more. Two of the 7 models (but not the FC or CRP values) identified patients without endoscopic activity with a negative predictive value (NPV) of 90% or more, leading to correct prediction of endoscopic healing in 3.2% to 11.3% of all patients. For example, applying the Herranz-Bachiller model (1 of 7 models) at a NPV of 92.1% and a positive predictive value of 91.9% correctly identified 35.7% of all patients in whom ileocolonoscopy could be avoided for expected endoscopic activity or healing but incorrectly identified 3.2% of all patients. Most ileocolonoscopies (66.5% in TAILORIX and 72.6% in the UAI of all ileocolonoscopies) could be avoided correctly based on concentrations of FC of 100 µg/g or less and 250 µg/g or higher. However, using this range of FC concentrations to identify patients who do not require ileocolonoscopy caused 18.7% of all patients in the TAILORIX cohort and 19.8% of all patients in the UAI cohort to be predicted incorrectly to have endoscopic activity or healing. CONCLUSIONS: In a systematic review and external validation of noninvasive models to identify patients with endoscopic activity of CD, we found only 2 of 7 models evaluated to have NPVs of 90% or more, however, leading to correctly predicted EH in only a small proportion of patients. Ileocolonoscopy therefore remains the mainstay to evaluate CD mucosal disease activity and healing.

Analytical and diagnostic performance of two automated fecal calprotectin immunoassays for detection of inflammatory bowel disease.

BACKGROUND: We evaluated the (pre-)analytical and diagnostic performance of two automated fecal calprotectin (FC) immunoassays, Liaison® Calprotectin (Diasorin) on Liaison® XL and fCAL™ turbo (Bühlmann laboratories AG) on Cobas C501 (Roche Diagnostics), and compared it with our established Bühlmann ELISA method. METHODS: Our study comprised 229 consecutive patients with clinical suspicion of inflammatory bowel disease (IBD). RESULTS: All assay related stool extraction procedures showed excellent correlation with the established method, but the new stool extraction devices tend to give higher results as compared with stool weight methods. Both automated assays demonstrated good performance in terms of precision (CVt≤8.1%), accuracy (bias≤6.7%) and total error (≤16.4%). Method comparison with established enzyme linked immunosorbent assay (ELISA) showed good correlation (rs>0.925), but regression analysis showed significant proportional differences. Diagnostic performance characteristics with regard to diagnosis of IBD were good and in line with other reports. In addition, we were able to show that optimization of manufacturer's cut-off and moreover, the introduction of a gray zone resulted in a significant increase of post-test probability. CONCLUSIONS: In conclusion, the newly developed stool extraction device protocols showed acceptable and comparable performance to the stool weight method. Overall, the automated Liaison® Calprotectin and fCAL™ turbo assay showed good analytical and diagnostic performance for detection of IBD.

Prophylactic Versus Endoscopy-driven Treatment of Crohn's Postoperative Recurrence: A Retrospective, Multicentric, European Study [PORCSE Study].

BACKGROUND AND AIMS: No consensus exists on optimal strategy to prevent postoperative recurrence [POR] after ileocaecal resection [ICR] for Crohn's disease [CD]. We compared early medical prophylaxis versus expectant management with treatment driven by findings at elective endoscopy 6-12 months after ICR. METHODS: A retrospective, multicentric, observational study was performed. CD patients undergoing first ICR were assigned to Cohort 1 if a biologic or immunomodulator was [re]started prophylactically after ICR, or to Cohort 2 if no postoperative prophylaxis was given and treatment was started as reaction to elective endoscopic findings. Primary endpoint was rate of endoscopic POR [Rutgeerts >i1]. Secondary endpoints were severe endoscopic POR [Rutgeerts i3/i4], clinical POR, surgical POR, and treatment burden during follow-up. RESULTS: Of 346 included patients, 47.4% received prophylactic postoperative treatment [proactive/Cohort 1] and 52.6% did not [reactive/Cohort 2]. Endoscopic POR [Rutgeerts >i1] rate was significantly higher in Cohort 2 [41.5% vs 53.8%, OR 1.81, p = 0.039] at endoscopy 6-12 months after surgery. No significant difference in severe endoscopic POR was found [OR 1.29, p = 0.517]. Cohort 2 had significantly higher clinical POR rates [17.7% vs 35.7%, OR 3.05, p = 0.002] and numerically higher surgical recurrence rates [6.7% vs 13.2%, OR 2.59, p = 0.051]. Cox proportional hazards regression analysis showed no significant difference in time to surgical POR of proactive versus expectant/reactive approach [HR 2.50, p = 0.057]. Quasi-Poisson regression revealed a significantly lower treatment burden for immunomodulator use in Cohort 2 [mean ratio 0.53, p = 0.002], but no difference in burden of biologics or combination treatment. CONCLUSIONS: The PORCSE study showed lower rates of endoscopic POR with early postoperative medical treatment compared with expectant management after first ileocaecal resection for Crohn's disease.

Faecal calprotectin: comparative study of the Quantum Blue rapid test and an established ELISA method.

BACKGROUND: Faecal calprotectin is a non-invasive marker for neutrophilic intestinal inflammation. It can be used in the differential diagnosis between functional and organic bowel disease. Moreover, it correlates with endoscopic organic bowel disease activity. The objective of this study is to evaluate a recently launched quantitative immunochromatographic point-of-care test: Quantum Blue Calprotectin (Bühlmann Laboratories AG, Schönenbuch, Switzerland) in comparison to an established ELISA method (Bühlmann Laboratories AG). METHODS: We included 142 samples, either archived (­80°C) faecal extracts or fresh routine samples. Both the normal range cartridges as well as the high range cartridge from the point-of-care test were used. The ELISA was compared with the point-of-care test and the optimal the point-of-care test cut-off values were searched for using Microsoft® Excel 2002 and MedCalc Software version 10.0.0.0 (Mariakerke, Belgium). RESULTS: In the method comparison a determination coefficient (R2) of 0.89 was found. The Passing Bablok regression analysis showed a significant deviation from linearity (y=­40.8+1.0x). The use of a cut-off value of 30 µg/g faeces and a grey zone of 30­110 µg/g faeces resulted in the best agreement between the ELISA interpretation and the point-of-care test interpretation, with 89.4% (127/142) agreement and 10.6% (15/142) mismatches. CONCLUSIONS: We may conclude that the point-of-care test can serve as a reliable alternative to the time consuming ELISA in the differential diagnosis between functional and organic bowel disease. Furthermore, it seems to be reliable in the follow-up of inflammatory bowel disease patients.

Pharmacokinetic-Pharmacodynamic Model of Vedolizumab for Targeting Endoscopic Remission in Patients With Crohn Disease: Posthoc Analysis of the LOVE-CD Study.

BACKGROUND: Higher serum concentrations of vedolizumab have been associated with improved outcomes in inflammatory bowel disease. It is unclear how vedolizumab exposure is linked to endoscopic remission in Crohn disease (CD). We aimed to develop a pharmacokinetic-pharmacodynamic model linking vedolizumab exposure to endoscopic remission in CD. METHODS: Data were obtained from the first 110 patients participating in a phase 4 prospective multicenter trial (LOVE-CD; ClinicalTrials.gov identifier: NCT02646683), where vedolizumab was dosed at 300 mg every 8 weeks and serum concentrations and antibodies to vedolizumab were measured before each infusion. Concentration-time profiles were described by a 2-compartment model with parallel linear and nonlinear elimination. A first-order discrete-time Markov model was used to describe the relationship between pharmacokinetic exposure metrics and the probability of endoscopic remission (Simple Endoscopic Score for CD < 4). RESULTS: Linear clearance was 0.215 L/d, and the volume of distribution of the central compartment was 4.92 L. Linear clearance was higher and vedolizumab exposure was lower in patients with lower serum albumin concentrations, in the presence of antibodies to vedolizumab, and in patients with previous exposure to other biologic therapy. A week 22 vedolizumab concentration of 20.0 mg/L was predicted to yield a 35% probability of achieving endoscopic remission at week 26. Model-based simulations suggested that endoscopic remission rates of 46.5% or 40.0% could be reached with every-4-weeks dosing in patients who were naïve or previously exposed to biologic therapy, respectively. CONCLUSIONS: Model-informed dosing of vedolizumab in CD provides a foundation for future research aiming to maximize endoscopic remission rates.

Long-term Outcome of Early Combined Immunosuppression Versus Conventional Management in Newly Diagnosed Crohn's Disease.

BACKGROUND AND AIMS: Long-term outcomes of early combined immunosuppression [top-down] compared to conventional management [step-up] in recently diagnosed Crohn's disease [CD] are unknown. We aimed to investigate long-term outcomes of participants of the Step-up/Top-down-trial. METHODS: Trial participants' medical records were reviewed retrospectively. For 16 semesters following the 2-year trial, we recorded: clinical activity, medication use, flares, hospitalization, surgery and fistulas. Colonoscopy reports were scored as: endoscopic remission, aphthous/small ulcers or large ulcers. The primary endpoint was the proportion of semesters in remission. RESULTS: Data were available from 119/133 patients [step-up n = 60]. During a median follow-up of 8 years, clinical remission rates were similar (70% vs 73% [p = 0.85] in step-up and top-down patients, respectively). A shorter time to flare was observed in step-up patients [median five vs nine semesters, p = 0.01]. Cumulatively, 62% of step-up patients used corticosteroids compared to 41% of top-down patients [p = 0.02]. Anti-tumour necrosis factor [anti-TNF] use was higher in the step-up group [73% vs 54%, p = 0.04]. No differences were found in to time to CD hospitalization [respectively 13 vs 14 semesters, p = 0.30], new fistula [14 vs 15 semesters, p = 0.20] or CD surgery [14 vs 15 semesters, p = 0.25]. Mucosal healing 2 years after treatment was associated with a reduced anti-TNF use, but not with differences in other long-term outcomes. Endoscopic remission occurred at similar rates between groups. CONCLUSIONS: Top-down treatment did not result in increased clinical remission during long-term follow-up, compared to step-up treatment. However, lower relapse rates and a reduced use of anti-TNF agents and corticosteroids were observed. No difference was found in rates of endoscopic remission, hospitalization, surgery or new fistulas.

Consecutive fecal calprotectin measurements to predict relapse in patients with ulcerative colitis receiving infliximab maintenance therapy.

BACKGROUND: This study examined whether fecal calprotectin can be used in daily practice as a marker to monitor patients with ulcerative colitis (UC) receiving infliximab maintenance therapy. METHODS: This prospective multicenter study enrolled adult patients with UC in clinical remission under infliximab maintenance therapy. Fecal calprotectin levels were measured every 4 weeks. Sigmoidoscopies were performed at inclusion and at study end. Relapse was defined as a clinical need for change in treatment or an endoscopic Mayo subscore of ≥2 at week 52. Sustained deep remission was defined as a partial Mayo score <3 at all points and an endoscopic Mayo score 0 at week 52. RESULTS: Full analysis was possible for 87 of 113 included patients with UC (77%). Of these patients, 30 (34.4%) were considered to be in sustained deep remission and 13 (14.9%) to have relapsed. Calprotectin levels in patients with sustained deep remission remained very low (median < 40 mg/kg at all time points). Patients who flared had significantly higher calprotectin levels (median > 300 mg/kg) already 3 months before the flare. Further receiver operator curve analysis suggested that a calprotectin level >300 mg/kg had a reasonable sensitivity (58.3%) and specificity (93.3%) to model flare. Two consecutive calprotectin measurements of >300 mg/kg with 1-month interval were identified as the best predictor of flare (61.5% sensitivity and 100% specificity). CONCLUSIONS: Fecal calprotectin can be used in daily practice to monitor patients with UC receiving infliximab maintenance therapy. Two consecutive measurements >300 mg/kg is more specific than a single measurement for predicting relapse.

Microsatellite instability in sporadic colon carcinomas has no independent prognostic value in a Belgian study population.

Pathological stage is currently the most important determinant of colorectal cancer prognosis. Hence, identification of additional prognostic markers is warranted. This study aimed to analyse the prognostic relevance of microsatellite instability (MSI) in 241 colon and 90 rectal tumours, using a mononucleotide loci multiplex PCR assay and immunohistochemistry. Thirty (12.4%) colon tumours and one rectal tumour showed MSI. Although MSI was associated with proximal location and poor differentiation, no survival benefit was observed. The prognostic value of stage and differentiation was confirmed in this study. Analysis by stage revealed a longer overall (stage II/III) and disease free survival (stage II) for patients with well differentiated tumours. In addition, age and distal localisation were related to longer overall survival in stage II tumours. In conclusion, our findings show an association of MSI in sporadic colon tumours and certain clinical features; however, they do not suggest a survival benefit for MSI tumours.