The Evolution of Treatment Paradigms in Crohn's Disease: Beyond Better Drugs

Time-to-reach Target Calprotectin Level in Newly Diagnosed Patients With Inflammatory Bowel Disease

OBJECTIVES

Treatment targets in inflammatory bowel disease (IBD) move away from controlling symptoms towards complete recovery of the intestinal mucosa. Currently, the most frequently used noninvasive surrogate marker of mucosal healing is a faecal calprotectin concentration in the target range. This study tested if there was a relation between time-to-reach target calprotectin and first flare.

METHODS

We prospectively included new-onset IBD patients ages 17 and younger in a cloud-based registry (FastForwardCare) and followed them for at least 52 weeks. They were treated according to Dutch national guidelines that advocate a step-up approach. Time-to-reach target was defined as the first calprotectin measurement below 250 μg/g after the start of induction therapy. Time-to-first flare was the time from the first calprotectin measurement below 250 μg/g until reappearance of symptoms with calprotectin values above 250 μg/g.

RESULTS

We included 76 patients (luminal Crohn disease [CD] 43); ulcerative colitis [UC] 33). Median age at diagnosis was, respectively 14.5 and 14.1 years. Median time-to-reach target calprotectin was 37 weeks in CD and 11 weeks in UC patients (Log-rank test, P = 0.001). Once the calprotectin target was reached, time-to-first flare was significantly longer in CD than in UC patients (Log-rank test, P = 0.001). CD patients with time-to-reach target calprotectin ≤12 weeks after conventional induction therapy (ie, exclusive enteral nutrition or steroids) had a more favorable disease course in the first year than those with time-to-reach target calprotectin >12 weeks (Log-rank test, P = 0.057). In UC patients, time-to-reach target calprotectin ≤12 weeks is not associated with a favorable disease course in the first year.

CONCLUSIONS

The findings of this prospective registry suggest that a quick response to conventional therapy predicts a favorable disease course in new-onset paediatric CD, but not in UC. The concept "time-to-reach target calprotectin level" rationalizes the indefinite term "response to treatment" and is well suited for studying treatment effectiveness in real-world practices.

The Evolving Role of Thiopurines in Inflammatory Bowel Disease

PURPOSE OF REVIEW

With the advent of biologic therapies for the treatment of inflammatory bowel disease, the roles of thiopurines have continued to evolve. This review will focus on recent advances in pharmacology and the safety and efficacy of thiopurines as maintenance therapies for steroid-induced remissions and post-surgical maintenance of remission and as combination therapies to reduce immunogenicities of biologic agents.

RECENT FINDINGS

Due to pharmacogenetics of thiopurine S-methyltransferase, thiopurine dosing is more effectively based on monitoring of thiopurine metabolites rather than weight-based dosing. Thiopurines continue to have a role as maintenance therapy after steroid-induced remissions and in combination with biologics to induce and maintain remission. Safety monitoring includes measurements of blood counts, liver chemistries, and dermatologic evaluations and protection from sun exposure. Thiopurines appear to be safe during pregnancies and while very uncommon, lymphomas (including hepatosplenic T cell lymphomas) remain a recognized risk, particularly in younger and older males.

A review of magnetic resonance enterography-based indices for quantification of Crohn's disease inflammation

Magnetic resonance enterography (MRE) is a leading radiological modality in Crohn's disease (CD) and is used together with laboratory findings and endoscopic examinations for the evaluation of patients during initial diagnosis and follow up. Over the years, there has been great progress in the understanding of CD and there is a continuous strive to achieve better monitoring of patients and to develop new modalities which will predict disease course and thus help in clinical decisions making. An objective evaluation of CD using a quantification score is not a new concept and there are different clinical, endoscopies, radiological and combined indices which are used in clinical practice. Such scores are a necessity in clinical trials on CD for evaluation of disease response, however, there is no consensus of the preferred MRE score and they are not routinely used. This review presents MRE-based indices in use in the last decade: the Magnetic Resonance Index of Activity (MaRIA), the Clermont score, the Crohn's Disease Magnetic Resonance Imaging (MRI) Index (CDMI), the Magnetic Resonance Enterography Global Score (MEGS) and the Lemann index. We compare the different indices and evaluate the clinical research that utilized them. The aim of this review is to provide a reference guide for researchers and clinicians who incorporate MRE indices in their work. When devising future indices, accumulated data of the existing indices must be taken into account, as each of the current indices has its own strengths and weakness.