Els Van de Vijver

Faecal calprotectin for screening of patients with suspected inflammatory bowel disease: diagnostic meta-analysis

Objective To evaluate whether including a test for faecal calprotectin, a sensitive marker of intestinal inflammation, in the investigation of suspected inflammatory bowel disease reduces the number of unnecessary endoscopic procedures. Design Meta-analysis of diagnostic accuracy studies. Data sources Studies published in Medline and Embase up to October 2009. Interventions reviewed Measurement of faecal calprotectin level (index test) compared with endoscopy and histopathology of segmental biopsy samples (reference standard). Inclusion criteria Studies that had collected data prospectively in patients with suspected inflammatory bowel disease and allowed for construction of a two by two table. For each study, sensitivity and specificity of faecal calprotectin were analysed as bivariate data to account for a possible negative correlation within studies. Results 13 studies were included: six in adults (n=670), seven in children and teenagers (n=371). Inflammatory bowel disease was confirmed by endoscopy in 32% (n=215) of the adults and 61% (n=226) of the children and teenagers. In the studies of adults, the pooled sensitivity and pooled specificity of calprotectin was 0.93 (95% confidence interval 0.85 to 0.97) and 0.96 (0.79 to 0.99) and in the studies of children and teenagers was 0.92 (0.84 to 0.96) and 0.76 (0.62 to 0.86). The lower specificity in the studies of children and teenagers was significantly different from that in the studies of adults (P=0.048). Screening by measuring faecal calprotectin levels would result in a 67% reduction in the number of adults requiring endoscopy. Three of 33 adults who undergo endoscopy will not have inflammatory bowel disease but may have a different condition for which endoscopy is inevitable. The downside of this screening strategy is delayed diagnosis in 6% of adults because of a false negative test result. In the population of children and teenagers, 65 instead of 100 would undergo endoscopy. Nine of them will not have inflammatory bowel disease, and diagnosis will be delayed in 8% of the affected children. Conclusion Testing for faecal calprotectin is a useful screening tool for identifying patients who are most likely to need endoscopy for suspected inflammatory bowel disease. The discriminative power to safely exclude inflammatory bowel disease was significantly better in studies of adults than in studies of children.

Safely ruling out inflammatory bowel disease in children and teenagers without referral for endoscopy

Background Up to 70% of children and teenagers referred to a paediatric gastroenterology centre with suspected inflammatory bowel disease (IBD) do not have the disease. Objective To evaluate whether faecal calprotectin as an ‘add-on test’ improves the specificity of the clinical case definition for suspected IBD in a general paediatric practice. Design A prospective diagnostic accuracy study. Setting Six outpatient clinics for general paediatrics and one tertiary care hospital in the Netherlands. Patients 117 children and teenagers with a clinical suspicion of IBD. Diagnostic tests Faecal calprotectin was measured (index test) in all patients. Patients with a high index of suspicion on the basis of the paediatricians global assessment, physical examination and blood results were referred for endoscopy (reference standard). Children and teenagers who were not selected for endoscopy initially were followed for half a year for the appearance of possible additional symptoms (delayed type reference standard). Primary outcome The proportion of referred patients with confirmed IBD. Results The mean age of patients was 14 years (range 6–18). A total of 42 (36%) had confirmed IBD. The paediatricians, who were blinded to the faecal calprotectin result, referred 68 children and teenagers for endoscopy. If they had referred only those patients with a positive faecal calprotectin result (>50 μg/g), 54 patients would have undergone endoscopy. Limitation The study relied on clinical follow-up to detect missed IBD. Conclusions A diagnostic strategy in general paediatric practice of using a simple clinical case definition for suspected IBD in combination with a positive faecal calprotectin result increases the specificity to detect IBD and reduces the need for referral to a paediatric gastroenterology centre with a very low risk of missing cases.

Treatment of Infants and Toddlers With Cystic Fibrosis-related Pancreatic Insufficiency and Fat Malabsorption With Pancrelipase MT

Background: Pancreatic enzyme replacement therapy (PERT) improves nutritional status and growth in patients with cystic fibrosis (CF) with pancreatic insufficiency (PI). The current recommendation for infants and young children, who are not able to swallow the whole capsule, is to open the capsule and mix the beads in a spoon with some applesauce; however, the efficacy and safety data of this approach are currently lacking. The aim of this study was to assess the efficacy, palatability (ease of swallowing), and safety of 4 dose levels of pancrelipase microtablets (Pancrease MT) in infants and young children with CF-related PI. Patients and Methods: This study was a phase II randomized, investigator-blinded, parallel-group pilot study in DNA-proven infants with CF and PI. The study design included a run-in period (days 1–5) and an experimental period (days 6–11). Pancrelipase microtablets (2-mm, enteric coated) were provided orally. Sixteen subjects, 6 to 30 months of age, were provided 500 U lipase/kg/meal for 5 days (baseline period). Subsequently, subjects were randomly assigned to 1 of 4 treatment groups (each n = 4), receiving 500, 1000, 1500, or 2000 U (Ph. EUR) of lipase/kg/meal, respectively, for 5 days (experimental period). The primary endpoint was medication efficacy assessed by the 72-hour fecal fat excretion, expressed as coefficient of fecal fat absorption (CFA), and 13C mixed triglyceride breath test. Secondary endpoints were safety and palatability. Results: Overall compliance, defined as used study medication, was 89% to 99% for the entire study. None of the 4 dose regimens significantly influenced the CFA, relative to the baseline period (median range 83%–93%). During the run-in period the median cumulative % 13C was 11 (range −8 to 59). After randomization the median cumulative % 13C was 18 (range 14–23) in the 500-U, 14 (range −1 to 17) in the 1000-U, 10 (range 10–27) in the 1500-U, and 3 (range 1–49) in the 2000-U groups. Palatability was scored fair to good by the parents in each of the treatment groups. Gastrointestinal symptoms were reported in some patients, including common adverse events reported in clinical trials involving pancreatic enzyme therapy. No serious or other adverse events were reported. Conclusion: Treatment with Pancrease MT at a dosage of 500 U lipase/kg/meal resulted in a CFA of approximately 89% in pediatric subjects ages 6 to 30 months with PI resulting from CF. Pancrease MT doses were well tolerated and mean palatability was scored as fair to good. Present results do not indicate that a dosage higher than 500 U (Ph. EUR) lipase/kg/meal increases the coefficient of fat absorption in a cohort of infants 6 to 30 months of age.

Faecal Calprotectin in Suspected Paediatric Inflammatory Bowel Disease

Objectives: The diagnostic accuracy of faecal calprotectin (FC) concentration for paediatric inflammatory bowel disease (IBD) is well described at the population level, but not at the individual level. We reassessed the diagnostic accuracy of FC in children with suspected IBD and developed an individual risk prediction rule using individual patient data. Methods: MEDLINE, EMBASE, DARE, and MEDION databases were searched to identify cohort studies evaluating the diagnostic performance of FC in paediatric patients suspected of having IBD. A standard study-level meta-analysis was performed. In an individual patient data meta-analysis, we reanalysed the diagnostic accuracy on a merged patient dataset. Using logistic regression analysis we investigated whether and how the FC value and patient characteristics influence the diagnostic precision. A prediction rule was derived for use in clinical practice and implemented in a spreadsheet calculator. Results: According to the study-level meta-analysis (9 studies, describing 853 patients), FC has a high overall sensitivity of 0.97 (95% confidence interval [CI] 0.92–0.99) and a specificity of 0.70 (0.59–0.79) for diagnosing IBD. In the patient-level pooled analysis of 742 patients from 8 diagnostic accuracy studies, we calculated that at an FC cutoff level of 50 &mgr;g/g there would be 17% (95% CI 15–20) false-positive and 2% (1–3) false-negative results. The final logistic regression model was based on individual data of 545 patients and included both FC level and age. The area under the receiver operating characteristic curve of this derived prediction model was 0.92 (95% CI 0.89–0.94). Conclusions: In high-prevalence circumstances, FC can be used as a noninvasive biomarker of paediatric IBD with only a small risk of missing cases. To quantify the individual patients’ risk, we developed a simple prediction model based on FC concentration and age. Although the derived prediction rule cannot substitute the clinical diagnostic process, it can help in selecting patients for endoscopic evaluation.

Slow Hematological Recovery in Children With IBD-associated Anemia in Cases of Expectant Management

Background and Objective: Allowing children with inflammatory bowel disease (IBD) to live with subnormal hemoglobin (Hb) levels affects their quality of life. The therapeutic approach to normalize Hb varies according to the cause of IBD-associated anemia. In exclusive iron-deficiency anemia (IDA) repletion of iron stores is obligatory, whereas controlling inflammation is the treatment of choice for anemia of chronic disease (ACD). In daily practice the focus is on control of intestinal inflammation, and spontaneous hematological recovery is awaited. The aim of the present study was to evaluate the hematological effect of “expectant management” on newly diagnosed pediatric patients with IBD with anemia. Patients and Methods: Medical records of children with IBD were reviewed. Study endpoints were the difference in Hb from the moment of IBD diagnosis (T0) to the end of the induction phase (T1), and time until normalization of Hb, stratified for the type of anemia at T0. Results: A total of 103 children were included in the study, of whom 80 (78%) had anemia at T0. Exclusive IDA was found in 58% of them. Expectant management caused a modest increase in Hb between T0 and T1 for both types of anemia (IDA 0.4 mmol/L; ACD 0.5 mmol/L), but 65 of 80 children (81%) still had anemia at T1. The proportion of children with exclusive IDA had increased to 74%. One third of the cases initially classified as having ACD had progressed to exclusive IDA. There was no significant difference in time until normalization of Hb between children with exclusive IDA and ACD. Twelve months after IBD diagnosis 24% of the group initially diagnosed as having exclusive IDA and 50% of the ACD group were still anemic. Conclusions: Hematological recovery in children with IBD-associated anemia is slow with expectant management, regardless of the type of anemia at T0. Present results underline the need for a more active approach to improve Hb.

Genetic screening of Congenital Short Bowel Syndrome patients confirms CLMP as the major gene involved in the recessive form of this disorder

Congenital short bowel syndrome (CSBS) is an intestinal pediatric disorder, where patients are born with a dramatic shortened small intestine. Pathogenic variants in CLMP were recently identified to cause an autosomal recessive form of the disease. However, due to the rare nature of CSBS, only a small number of patients have been reported to date with variants in this gene. In this report, we describe novel inherited variants in CLMP in three CSBS patients derived from two unrelated families, confirming CLMP as the major gene involved in the development of the recessive form of CSBS.

Long-term Outcomes with Anti-TNF Therapy and Accelerated Step-up in the Prospective Pediatric Belgian Crohn's Disease Registry (BELCRO)

Background: Accelerated step-up or anti–tumor necrosis factor (TNF) before first remission is currently not recommended in pediatric Crohns disease. Methods: Five-year follow-up data from a prospective observational cohort of children diagnosed with Crohns disease in Belgium were analyzed. Disease severity was scored as inactive, mild, or moderate to severe. Remission or inactive disease was defined as sustained if lasting ≥2 years. Univariate analyses were performed between anti-TNF–exposed versus naive patients and anti-TNF before versus after first remission and correlations assessed with primary outcomes average disease severity and sustained remission. Results: A total of 91 patients (median [IQR] age 12.7 [10.9–14.8] yrs, 53% male) were included. Disease location was 12% L1, 23% L2, and 64% L3 with 76% upper gastrointestinal and 30% perianal involvement. Disease severity was 25% mild and 75% moderate to severe. Of 66 (73%) anti-TNF–exposed patients, 34 (52%) had accelerated step-up. Anti-TNF use was associated with age (13.1 [11.5–15.2] versus 11.8 [8.7–13.8] yrs; P < 0.05), L2 (29% versus 8%; P = 0.04), and average disease severity (1.7 [1.4–1.9] versus 1.4 [1.3–1.6]; P < 0.001). Duration of anti-TNF correlated with average disease severity (r = 0.32, P = 0.002). Accelerated step-up was also associated with age (13.3 [12.1–15.9] versus 12.5 [10.2–14.1]; P = 0.02) and average disease severity (1.8 [1.6–1.9] versus 1.6 [1.3–1.8]; P = 0.002). Duration of sustained remission was similar in all patients, and no serious infections, cancer, or deaths were reported. Conclusions: Anti-TNF therapy and accelerated step-up in older patients with more severe disease leads to beneficial long-term outcomes.

Selecting children with suspected inflammatory bowel disease for endoscopy with the calgranulin C or calprotectin stool test: protocol of the CACATU study

Introduction The introduction of the faecal calprotectin (FC) test to screen children with chronic gastrointestinal complaints has helped the clinician to decide whether or not to subject the patient to endoscopy. In spite of this, a considerable number of patients without inflammatory bowel disease (IBD) is still scoped. Faecal calgranulin C (S100A12) is a marker of intestinal inflammation that is potentially more specific for IBD than FC, as it is exclusively released by activated granulocytes. Objective To determine whether the specificity of S100A12 is superior to the specificity of FC without sacrificing sensitivity in patients with suspected IBD. Methods An international prospective cohort of children with suspected IBD will be screened with the existing FC stool test and the new S100A12 stool test. The reference standard (endoscopy with biopsies) will be applied to patients at high risk of IBD, while a secondary reference (clinical follow-up) will be applied to those at low risk of IBD. The differences in specificity and sensitivity between the two markers will be calculated. Ethics and dissemination This study is submitted to and approved by the Medical Ethics Review Committee of the University Medical Center Groningen (the Netherlands) and the Antwerp University Hospital (Belgium). The results will be disseminated through a peer-reviewed publication, conference presentation and incorporation in the upcoming National Guideline on Diagnosis and Therapy of IBD in Children. Trial registration ClinicalTrials.gov identifier: NCT02197780 .

Gastric fluid composition in a paediatric population: Age-dependent changes relevant for gastrointestinal drug disposition

ABSTRACT This work aimed to (i) expand the dataset on gastric fluid composition in the paediatric population (0–18 years old) and (ii) improve our understanding of age‐dependent changes in gastric fluid characteristics involved in gastrointestinal drug disposition. For this purpose, gastric fluids from preterm neonates, term neonates, infants, children and adolescents were collected during routine medical procedures. Gastric fluid constituents relevant for gastrointestinal drug disposition were characterized i.e., pH, osmolality and bile salts (concentration + composition). Differences in gastric fluid composition compared to adults were most prominent in neonates. In this context, the fact that neonates are rarely fasted due to frequent feedings should be taken into account during paediatric drug product development. It remains to be explored to what extent the observed variability and differences in gastric fluid characteristics within and between age groups translates to variability and/or differences in oral drug disposition. Graphical abstract Figure. No Caption available.

Predicting inflammatory bowel disease in children with abdominal pain and diarrhoea: calgranulin-C versus calprotectin stool tests

Objective Calgranulin-C (S100A12) is a new faecal marker of inflammation that is potentially more specific for inflammatory bowel disease (IBD) than calprotectin, since it is only released by activated granulocytes. We compared calgranulin-C and calprotectin to see which of the two tests best predicted IBD in children with chronic abdominal pain and diarrhoea. Design Delayed-type cross-sectional diagnostic study. Setting and patients Previously undiagnosed patients aged 6–17 years, who were seen in paediatric clinics in the Netherlands and Belgium, sent in a stool sample for analysis. Patients with a high likelihood of IBD underwent upper and lower endoscopy (ie, preferred reference test), while those with a low likelihood were followed for 6 months for latent IBD to become visible (ie, alternative reference test). We used Bayesian modelling to correct for differential verification bias. Main outcome measures Primary outcome was the specificity for IBD using predefined test thresholds (calgranulin-C: 0.75 µg/g, calprotectin: 50 µg/g). Secondary outcome was the test accuracy with thresholds based on receiver operating characteristics (ROC) analysis. Results IBD was diagnosed in 93 of 337 patients. Calgranulin-C had significantly better specificity than calprotectin when predefined thresholds were used (97% (95% credible interval (CI) 94% to 99%) vs 71% (95% CI 63% to 79%), respectively). When ROC-based thresholds were used (calgranulin-C: 0.75 µg/g, calprotectin: 400 µg/g), both tests performed equally well (specificity: 97% (95% CI 94% to 99%) vs 98% (95% CI 95% to 100%)). Conclusions Both calgranulin-C and calprotectin have excellent test characteristics to predict IBD and justify endoscopy. Trial registration number NCT02197780.