Tim de Meij

Electronic nose can discriminate colorectal carcinoma and advanced adenomas by fecal volatile biomarker analysis: proof of principle study

In the course and prognosis of colorectal cancer (CRC), early detection and treatment are essential factors. Fecal immunochemical tests (FITs) are currently the most commonly used non‐invasive screening tests for CRC and premalignant (advanced) adenomas, however, with restricted sensitivity. We hypothesized that fecal volatile organic compounds (VOCs) may serve as a diagnostic biomarker of CRC and adenomas. In this proof of concept study, we aimed to assess disease‐specific VOC smellprints in fecal gas to distinguish patients with CRC and advanced adenomas from healthy controls. Fecal samples of patients who were scheduled to undergo an elective colonoscopy were collected. An electronic nose (Cyranose 320®) was used to measure VOC patterns in fecal gas from patients with histopathologically proven CRC, with advanced adenomas and from controls (no abnormalities seen at colonoscopy). Receiver operator characteristic curves and corresponding sensitivity and specificity for detection of CRC and advanced adenomas were calculated. A total of 157 stool samples (40 patients with CRC, 60 patients with advanced adenomas, and 57 healthy controls) were analyzed by electronic nose. Fecal VOC profiles of patients with CRC differed significantly from controls (area under curve ± 95%CI, p‐value, sensitivity, specificity; 0.92 ± 0.03, <0.001, 85%, 87%). Also VOC profiles of patients with advanced adenomas could be discriminated from controls (0.79 ± 0.04, <0.001, 62%, 86%). The results of this proof of concept study suggest that fecal gas analysis by an electronic nose seems to hold promise as a novel screening tool for the (early) detection of advanced neoplasia and CRC.

The Scent of Colorectal Cancer: Detection by Volatile Organic Compound Analysis

The overall metabolic state of an individual is reflected by emitted volatile organic compounds (VOCs), which are gaseous carbon-based chemicals. In this review, we will describe the potential of VOCs as fully noninvasive markers for the detection of neoplastic lesions of the colon. VOCs are detected by our sensory olfactory nerves and form the molecular basis for our sense of smell. As such, we emit our own individual odor fingerprint or so-called smellprint. This may change over time in response to any alteration in metabolism such as modifications caused by gastrointestinal infection, inflammation, external factors such as medication and diet, or development of neoplastic disease such as colorectal cancer. This means that analysis of VOCs can provide a fully noninvasive metabolomics biomarker profile that could be used as a diagnostic tool. Thus far, canine scent detection, gas chromatography-mass spectrometry, and electronic nose technologies allow for discrimination between patients with and without colorectal cancer and also its precursor (advanced adenoma) with promising accuracy. The challenge for future research is to identify specific biomarkers driving these signals. This enables the development of primed sensors tailored toward accurate identification of volatiles specific to colorectal cancer and adenomas. Such a technique may allow noninvasive monitoring of response to therapy and could revolutionize screening practices for colorectal cancer and potentially many other gastrointestinal diseases.

An open study of paroxetine in hypochondriasis

1. Despite the high prevalence of hypochondriasis, this disorder is found to be the focus of research only minimally. 2. This open study evaluates the efficacy and tolerance of paroxetine in 11 patients with DSM-III-R hypochondriasis. 3. Using paired samples t-test, a significant reduction on measures of hypochondriasis was found after 12 weeks of treatment compared to baseline. Two patients dropped out prematurely. At post-test, eight out of nine patients who completed the study had improved to a clinically relevant degree. Of these, five attained scores in the reach of the normal population. 4. In one patient who completed the study and one patient who dropped out, tolerance of paroxetine was poor, whereas in remaining patients tolerance was moderate to good. 5. The results of this study suggest that patients with hypochondriasis may be responsive to paroxetine. A controlled study is recommended.

The association of infliximab trough levels with disease activity in pediatric inflammatory bowel disease.

Abstract Objective. Low serum trough levels (TLs) of infliximab (IFX) and antibodies to IFX (ATIs) are associated with the loss of therapeutic response in adults with inflammatory bowel disease (IBD) receiving IFX. Until now, pediatric data are scarce. Therefore, we aimed to cross-sectionally investigate the association between ATIs and IFX TLs, and clinical and biochemical disease activity in children receiving IFX for IBD. Material and methods. Children aged <18 years receiving IFX maintenance treatment for Crohn’s disease (CD) or ulcerative colitis (UC) at three Dutch hospitals were included. Prior to two consecutive IFX infusions, IFX TLs and ATI levels were measured. Clinical disease activity was determined by Pediatric Crohn’s Disease Activity Index (PCDAI) and Pediatric Ulcerative Colitis Activity Index (PUCAI), for CD and UC, respectively. Biochemical disease activity was assessed by serum C-reactive protein (CRP) and fecal calprotectin (FC). Clinical remission was defined as a PUCAI or PCDAI score of <10. Therapeutic range of IFX was considered 3–7 µg/ml. Results. Thirty-nine patients were included (31 CD; 16 females). Median age was 15 years. Median IFX TL was 3.5 µg/ml [IQR 2–7]. Subtherapeutic and supratherapeutic TLs were found in 38% and 23% of children, respectively. ATIs were detected in four patients. A correlation was found between IFX TL and CRP [rs = −0.51; p < 0.01] and FC [rs = −0.49; p < 0.01]. However, when only clinical disease activity was considered, no difference in median TL was found between remission and active disease (resp. 3.5 µg/ml [IQR 2–5] and 2.3 µg/ml [IQR 0.3–4.6]; p = 0.2). Conclusions. IFX TLs are related to biochemical markers of disease activity. This could provide a rationale for monitoring TLs in children receiving IFX for IBD.

Necrotizing enterocolitis: a clinical review on diagnostic biomarkers and the role of the intestinal microbiota

AbstractNecrotizing enterocolitis (NEC) remains one of the most frequent gastrointestinal diseases in the neonatal intensive care unit, with a continuing unacceptable high mortality and morbidity rates. Up to 20% to 40% of infants with NEC will need surgical intervention at some point. Although the exact pathophysiology is not yet elucidated, prematurity, use of formula feeding, and an altered intestinal microbiota are supposed to induce an inflammatory response of the immature intestine. The clinical picture of NEC has been well described. However, an early diagnosis and differentiation against sepsis is challenging. Besides, it is difficult to timely identify NEC cases that will deteriorate and need surgical intervention. This may interfere with the most optimal treatment of infants with NEC. In this review, we discuss the pathogenesis, diagnosis, and treatment of NEC with a focus on the role of microbiota in the development of NEC. An overview of different clinical prediction models and biomarkers is given. Some of these are promising tools for accurate diagnosis of NEC and selection of appropriate therapy.

Faecal gas analysis by electronic nose as novel, non-invasive method for assessment of active and quiescent paediatric inflammatory bowel disease: Proof of principle study.

BACKGROUND AND AIMS Inflammatory bowel disease (IBD) and its two phenotypes ulcerative colitis (UC) and Crohns disease (CD) are essentially assessed by endoscopy, both in initial diagnostic work-up and during follow-up. This carries a high burden, especially on paediatric patients. Faecal volatile organic compounds (VOCs) are considered potential non-invasive biomarkers for intestinal diseases linked to gut microbiota alterations. We hypothesized that faecal VOC analysis by electronic nose allows discrimination of children with CD, UC and controls during active disease and remission. METHODS Faecal VOC patterns of children with newly diagnosed IBD and controls were studied by an electronic nose (Cyranose 320®), at baseline and upon achieving remission at 6-weeks of follow-up. Disease activity was assessed by global physicians assessment, substantiated by serum C-reactive protein and faecal calprotectin. Internally cross-validated receiver-operator-characteristic curves and corresponding sensitivity and specificity for detection of IBD were calculated RESULTS: Faecal VOC profiles of patients with UC (26) and CD (29) differed from controls (28); in active disease (AUC±95% CI, p-value, sensitivity, specificity: 1.00±0.00; p<0.001, 100%, 100%) and (0.85±0.05, p<0.001, 86%, 67%) and in clinical remission (0.94±0.06, p<0.001, 94%, 94%) and (0.94±0.06, p<0.001, 94%, 94%), respectively. Furthermore, CD-patients differed from UC-patients during active disease (0.96±0.03; p<0.001, 97%, 92%), and upon achieving clinical remission (0.81±0.08, p=0.002, 88%, 72%). CONCLUSION Faecal VOC analysis allowed discrimination of paediatric patients with IBD from controls, both during active disease and remission. It therefore has potential as non-invasive test, in both diagnostic work-up and assessment of disease activity in IBD.

Composition and stability of intestinal microbiota of healthy children within a Dutch population

Numerous diseases linked to microbial imbalance can be traced back to childhood, illustrating the impact of the juvenile microbiota development from infancy toward adulthood. However, knowledge on this subject is currently very limited. The primary aim of this study was to characterize composition and short‐ and long‐term stability of the intestinal microbiota in healthy children. Between November 2011 and June 2014, 61 children 2 to 18 yr of age from different areas in The Netherlands were included and instructed to collect fecal samples weekly, for 6 wk, and a follow‐up sample after 18 mo. The intergenic spacer profiling technique (IS‐pro) was used to analyze all available fecal samples. Microbial diversity was calculated by the Shannon diversity index and individual compositional stability by comparing all collection time points. Microbial stability varied per phylum (P < 0.0005), declined rapidly in a short time period, and subsequently stabilized on the long run with very gradual variation, leading to an overall compositional stability of 70% on average over a period of 18 mo. Higher species diversity was correlated to a higher overall compositional stability (P< 0.001). We observed an age‐independent bacterial shared core consisting of a limited number of species. In conclusion, in this study, we showed that microbial composition stability in children varied per phylum, at both short‐term and long‐term intervals. Healthy children seem to share a microbiome core consisting of a limited number of species.—De Meij, T. G. J., Budding, A. E., de Groot, E. F. J., Jansen, F. M., Kneepkens, C. M. F., Benninga, M. A., Penders, J., van Bodegraven, A. A., Savelkoul, P. H. M. Composition and stability of intestinal microbiota of healthy children within a Dutch population. FASEB J. 30, 1512–1522 (2016). www.fasebj.org

Pediatric Achalasia in the Netherlands: Incidence, Clinical Course, and Quality of Life.

OBJECTIVE To assess incidence and clinical course of Dutch patients with achalasia diagnosed before 18 years of age as well as their current symptoms and quality of life (QoL). STUDY DESIGN Retrospective medical chart review and a cross-sectional study assessing current clinical status using the Eckardt score and reflux disease questionnaire. General QoL was measured using Kidscreen-52 for patients <18 years of age or to 36-Item Short Form Health Survey for patients ≥18 years of age. RESULTS Between 1990 and 2013, 87 children (mean age 11.4 ± 3.4 years, 60% male) diagnosed with achalasia in the Netherlands were included. Mean incidence was 0.1/100,000/y (range 0.03-0.21). Initial treatment was pneumodilation (PD) in 68 (79%) patients and Heller myotomy (HM) in 18 (21%) patients. Retreatment was required more often after initial PD compared with initial HM (88% vs 22%; P < .0001). More complications of initial treatment occurred after HM compared with PD (55.6% vs 1.5%; P < .0001). Three esophageal perforations were seen after HM (16.7%), 1 after PD (1.5%). Sixty-three of 87 (72%) patients were prospectively contacted. Median Eckardt score was 3 (IQR 2-5), with 32 patients (44.5%) having positive scores suggesting active disease. Reflux disease questionnaire scores were higher after initial HM vs PD (1.71 [0.96-2.90] vs 0.58 [0-1.56]; P = .005). The 36-Item Short Form Health Survey (n = 52) was lower compared with healthy population norms for 7/8 domains. Kidscreen-52 (n = 20) was similar to population norms. CONCLUSIONS Pediatric achalasia is rare and relapse rates are high after initial treatment, especially after pneumodilation, but with more complications after HM. Symptoms often persist into adulthood, without any clinical follow-up. QoL in adulthood was decreased.

Adalimumab therapy in children with Crohn disease previously treated with infliximab

Objectives: Adalimumab, a humanised anti-tumour necrosis factor antibody, is an effective treatment in adult patients with refractory Crohn disease (CD). The available literature on its efficacy in children remains limited. We aimed to evaluate the real-world efficacy in paediatric patients with CD and compare the efficacy between infliximab (IFX) nonresponders and patients who lost response to IFX. Methods: All Dutch patients with CD receiving adalimumab before the age of 18 years after previous IFX therapy were identified. We analysed longitudinal disease activity, assessed by the mathematically weighted Pediatric Crohns Disease Activity Index (wPCDAI) or the physician global assessment (PGA), and adverse events (AEs). Results: Fifty-three patients with CD were included. Twelve patients received monotherapy and the others received combination treatment with thiopurines (n = 21), methotrexate (n = 11), steroids (n = 7), or exclusive enteral nutrition (n = 2). Median follow-up was 12 months (interquartile range 5–23). Remission was reached in 34 patients (64%, wPCDAI < 12.5 or PGA = 0) after a median of 3.3 months, and maintained by 50% for 2 years. Eleven patients (21%) reached response but not remission (decrease in wPCDAI ≥ 17.5 or decrease in PGA). Eighteen patients (34%) failed adalimumab treatment because of nonresponse (n = 4), lost response (n = 11), or AEs (n = 3). More IFX nonresponders failed adalimumab treatment than patients who lost response to IFX (2/3 vs 8/34, hazard ratio 18.8, 95% confidence interval 1.1–303.6). Only 1 patient encountered a serious AE, a severe but nonfatal infection. Conclusions: In clinical practice, adalimumab induces remission in two-thirds of children with IFX refractory CD.

Methotrexate for maintaining remission in paediatric Crohn's patients with prior failure or intolerance to thiopurines: a multicenter cohort study.

BACKGROUND AND AIMS Methotrexate [MTX] is an immunomodulating drug that can be used to maintain remission in patients with Crohns disease [CD], but data on efficacy and tolerability in children and teenagers are scarce. We evaluated the long-term efficacy and tolerability of MTX monotherapy after thiopurine therapy in paediatric CD patients. METHODS A multicenter cohort of paediatric MTX users who stopped thiopurines due to ineffectiveness or intolerance between 2002 and 2012 were included and followed for at least 12 months. Relapse-free use was defined as steroid and biologics-free clinical remission after the introduction of MTX, and included intentional discontinuation of successful therapy before the end of the observation period. RESULTS A total of 113 patients with CD in remission were followed while on MTX monotherapy, of whom 75 [66%] had failed on thiopurines and 38 [34%] had stopped thiopurines due to side effects. Median age at the introduction of MTX was 14 years [range 7 to 17], and 93% used the subcutaneous route. Kaplan-Meier analysis showed that 52% of the study cohort were still in steroid- and biologics-free remission after 12 months of MTX monotherapy, with a difference that did not reach significance between thiopurine-intolerant and thiopurine-failing patients [p = 0.21, log-rank test]. CONCLUSIONS The findings of this cohort study suggest that MTX is an effective immunomodulator to maintain remission after stopping thiopurines. MTX maintenance should be considered before stepping up to anti-tumor necrosis factor alpha therapy. MTX is probably somewhat more effective in patients who stopped thiopurines due to side effects than in those who failed on thiopurines.