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Background and Aims: Therapeutic drug monitoring (TDM) of infliximab (IFX) and anti-infliximab antibodies (ATIs) is essential for treatment optimisation in inflammatory bowel disease (IBD) patients. The aim of this study was to estimate and compare the agreement and accuracy between a new rapid test and three established enzyme-linked immunosorbent assays (ELISAs) to quantify ATIs levels, and to evaluate the impact of exogenous IFX on the performance of these assays. Methods: We analysed 200 serum samples from 57 IBD outpatients in IFX induction or maintenance therapy at six IBD centres in Portugal. ATI levels were quantified using the rapid test Quantum Blue® (QB) Anti-Infliximab (Bühlmann) and three established ELISAs: In-House, Theradiag (Lisa Tracker Anti-Infliximab), and Immundiagnostik (IDKmonitor Infliximab). ATIs were quantified in patients’ serum samples and spiked samples with exogenous IFX, based on analytical and clinical cutoffs. Qualitative agreement and accuracy were estimated by Cohen’s kappa ( k) with 95% confidence intervals. Results: ATIs quantification with clinical cutoffs showed a slight agreement between QB rapid test and In-House [ k = 0.163 (0.051–0.276)] and Immundiagnostik [ k = 0.085 (0.000–0.177)]. Regarding IFX/ATIs status, the QB rapid test showed a substantial agreement with Theradiag [ k = 0.808 (0.729–0.888)] and a fair agreement with In-House [ k = 0.343 (0.254–0.431)] and Immundiagnostik [ k = 0.217 (0.138–0.297)]. The QB rapid test could not detect ATI-positive levels in samples with exogenous IFX at 5–300 µg/ml. Interference on ATIs detection was observed at exogenous IFX ⩾30 µg/ml for In-house and Immundiagnostik assays. Conclusion: QB rapid test is only suitable to detect ATI-positive levels in the absence of IFX.

Background The prevalence of inflammatory bowel disease (IBD) has been increasing worldwide, causing high impact on the quality of life of patients and an increasing burden for health care systems. In this systematic review, we reviewed the literature concerning the direct costs of Crohn’s disease (CD) for health care systems from different perspectives: regional, economic, and temporal. Methods We searched for original real-world studies examining direct medical health care costs in Crohn’s disease. The primary outcome measure was the mean value per patient per year (PPY) of total direct health care costs for CD. Secondary outcomes comprised hospitalization, surgery, CD-related medication (including biologics), and biologics mean costs PPY. Results A total of 19 articles were selected for inclusion in the systematic review. The studies enrolled 179 056 CD patients in the period between 1997 and 2016. The pooled mean total cost PPY was €6295.28 (95% CI, €4660.55-€8503.41). The pooled mean hospitalization cost PPY for CD patients was €2004.83 (95% CI, €1351.68-€2973.59). The major contributors for the total health expenditure were biologics (€5554.58) and medications (€3096.53), followed by hospitalization (€2004.83) and surgery (€1883.67). No differences were found between regional or economic perspectives, as confidence intervals overlapped. However, total costs were significantly higher after 2010. Conclusions Our review highlighted the burden of CD for health care systems from different perspectives (regional, economic, and temporal) and analyzed the impact of the change of IBD treatment paradigm on total costs. Reducing the overall burden can depend on the increase of remission rates to further decrease hospitalizations and surgeries.

INTRODUCTION: Patients with elderly-onset inflammatory bowel disease were previously associated with a less aggressive course of the disease. However, there are conflicting data that need further validation. We aimed to determine the association between age at diagnosis and the development of progressive disease in patients with Crohn's disease (CD) and ulcerative colitis (UC). METHODS: This cohort study included patients with CD and UC followed in 6 secondary and tertiary care centers in mainland Portugal. Patients were divided into a derivation (80%) cohort and a validation (20%) cohort. The primary outcome was progressive disease. Logistic regression analysis, receiver operating characteristic curves, and the areas under the curve (AUC) were performed. Odds ratios with 95% confidence intervals (CIs) were estimated. RESULTS: The derivation cohorts included 1245 patients with CD (68% with progressive disease) and 1210 patients with UC (37% with progressive disease), whereas the validation cohorts included 302 patients with CD and 271 patients with UC, respectively, with similar outcome proportions. In our final model, age at diagnosis older than 60 years was significantly associated with a lower risk of developing progressive disease (odds ratio 0.390, 95% CI 0.164–0.923, P = 0.032), with a high discriminative power (AUC 0.724, 95% CI 0.693–754) in patients with CD. However, according to this model, no significant associations were found between age at diagnosis and the risk of developing progressive disease in patients with UC. No differences were observed in the AUC values between the validation and the derivation cohorts. DISCUSSION: Patients with elderly-onset CD, but not patients with UC, were associated with a less progressive course of the disease.

Background and Aims The availability of biological agents for inflammatory bowel disease has increased over the past years. In this systematic review and meta‐analysis, we aimed to explore time trends in clinical response and clinical remission rates in Crohn's disease (CD) patients treated with biologics while discussing the need for new strategies. Methods MEDLINE, Cochrane, and ISI Web of Science databases were searched for randomized placebo‐controlled trials with biological agents in moderate‐to‐severe CD patients. Sub‐group and meta‐regression analyses compared treatment and placebo by calculating the pooled odds ratios of clinical remission and clinical response, across time categories and publication year. We also estimated the proportion of patients achieving clinical remission and clinical response by comparing both groups according to the publication year. Results Twenty‐five trials were included in the systematic review, which enrolled 8879 patients between 1997 and 2022. The clinical remission and clinical response odds, in induction and maintenance, have been constant over time, as no statistically significant differences were found between time categories (interaction p‐values: clinical remission [induction, p = 0.19; maintenance, p = 0.24]; clinical response [induction, p = 0.43; maintenance, p = 0.59]). In meta‐regression analyses, publication year did not influence these outcomes (clinical remission [induction, OR 1.01{95% CI 0.97–1.05}, p = 0.72; clinical response [induction, OR 1.01{95% CI 0.97–1.04]; p = 0.63; maintenance, OR 1.03{95% CI 0.98–1.07}; p = 0.21]), with the exception of clinical remission in maintenance studies, which presented a decreased effect (odds ratio 0.97{95% CI 0.94–1.00}, p = 0.03]). Conclusions Our review highlights that the odds of clinical outcomes in CD patients receiving biological treatment relative to placebo have been stable in the last decades.