Nanne de Boer

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.

H1N1 vaccines in a large observational cohort of patients with inflammatory bowel disease treated with immunomodulators and biological therapy

Background Safety data are lacking on influenza vaccination in general and on A (H1N1)v vaccination in particular in patients with inflammatory bowel disease (IBD) receiving immmunomodulators and/or biological therapy. Aims and methods The authors conducted a multicentre observational cohort study to evaluate symptoms associated with influenza H1N1 adjuvanted (Pandemrix, Focetria, FluvalP) and non-adjuvanted (Celvapan) vaccines and to assess the risk of flare of IBD after vaccination. Patients with stable IBD treated with immunomodulators and/or biological therapy were recruited from November 2009 until March 2010 in 12 European countries. Harvey–Bradshaw Index and Partial Mayo Score were used to assess disease activity before and 4 weeks after vaccination in Crohns disease (CD) and ulcerative colitis (UC). Vaccination-related events up to 7 days after vaccination were recorded. Results Of 575 patients enrolled (407 CD, 159 UC and nine indeterminate colitis; 53.9% female; mean age 40.3 years, SD 13.9), local and systemic symptoms were reported by 34.6% and 15.5% of patients, respectively. The most common local and systemic reactions were pain in 32.8% and fatigue in 6.1% of subjects. Local symptoms were more common with adjuvanted (39.3%) than non-adjuvanted (3.9%) vaccines (p<0.0001), whereas rates of systemic symptoms were similar with both types (15.0% vs 18.4%, p=0.44). Among the adjuvanted group, Pandemrix more often induced local reactions than FluvalP and Focetria (51.2% vs 27.6% and 15.4%, p<0.0001). Solicited adverse events were not associated with any patient characteristics, specific immunomodulatory treatment, or biological therapy. Four weeks after vaccination, absence of flare was observed in 377 patients with CD (96.7%) and 151 with UC (95.6%). Conclusion Influenza A (H1N1)v vaccines are well tolerated in patients with IBD. Non-adjuvanted vaccines are associated with fewer local reactions. The risk of IBD flare is probably not increased after H1N1 vaccination.

Promising treatment of autoimmune hepatitis with 6-thioguanine after adverse events on azathioprine.

The use of corticosteroids in autoimmune hepatitis is an established therapy. To avoid the possible serious side effects of corticosteroids, immunosuppression with azathioprine is often warranted. Azathioprine, a purine analogue, is frequently used to taper or replace corticosteroids. However, approximately 10% of the patients are intolerant to azathioprine. Alternative therapies using mycophenolate, tacrolimus, budesonide, cyclosporine and 6-mercaptopurine have been studied, with variable results. The use of 6-thioguanine, an agent more directly leading to the down-stream active metabolites of azathioprine (6-thioguanine nucleotides) in inflammatory bowel disease patients intolerant to azathioprine or 6-mercaptopurine showed conflicting results. We report three patients with autoimmune hepatitis who could not tolerate azathioprine but tolerated 6-thioguanine 0.3 milligram per kilogram daily well. All three patients improved clinically. Therapeutic drug monitoring was performed. The prospective evaluation of 6-thioguanine as a possible immunosuppressive drug in autoimmune hepatitis patients is warranted.

Prolonged thioguanine therapy is well tolerated and safe in the treatment of ulcerative colitis

BACKGROUND Thioguanine has been used for the treatment of inflammatory bowel disease, in particular for patients who failed conventional thiopurine therapy. To date, thioguanine has been infrequently studied in ulcerative colitis. AIM To evaluate the tolerability, safety and efficacy of thioguanine in the treatment of ulcerative colitis. METHODS A database analysis was performed on inflammatory bowel disease patients who had failed conventional thiopurine therapy and were treated with thioguanine. Rates and reasons for treatment failure were assessed. Laboratory values, abdominal ultrasonography, liver biopsy and endoscopic remission rates were evaluated. RESULTS Forty-six patients were included and median treatment duration was 22 months (range 0.3-72.0). Nine patients failed thioguanine therapy: six due to adverse events, three due to therapy resistance. Concomitant treatment with aminosalicylates protected against thioguanine failure (hazard ratio (HR) 0.11, 95% CI 0.03-0.48). When performed, ultrasonography (n = 21) revealed no suspected therapy-related pathology in all but one patient, in whom hepatomegaly was observed. Liver histology (n = 12) predominantly revealed no abnormalities (n = 4) or non-specific regeneration (n = 4); none showed nodular regenerative hyperplasia. At follow-up, 40% of colonoscopies revealed endoscopic remission as compared with 10% at baseline (P = 0.180). CONCLUSIONS Long-term use of thioguanine appears to be well tolerated and relatively safe in ulcerative colitis patients who failed conventional thiopurine therapy.

6-Thioguanine for Crohn's disease during pregnancy: thiopurine metabolite measurements in both mother and child

6-Thioguanine is used as an escape thiopurine for treating inflammatory bowel disease patients intolerant or refractory to azathioprine, 6-mercaptopurine or methotrexate. Case reports show conflicting data on the use of 6-thioguanine throughout pregnancy. The administration of the standard thiopurines is believed to be relatively safe. We describe two patients with Crohns disease treated with low-dose 6-thioguanine during all trimesters of their pregnancies. The pregnancies resulted in two healthy infants: without congenital abnormalities, laboratory signs of myelosuppression or hepatocellular injury. Thiopurine metabolites were measured in mother and infant. Significantly lower levels of 6-thioguaninenucleotides were found in the erythrocytes of the infant compared to the mother (ratio 1:12). Further studies are needed to determine the clinical importance of thiopurine metabolite measurements during pregnancy in mother and child.

On Therapeutic Drug Monitoring of Thiopurines in Inflammatory Bowel Disease; Pharmacology, Pharmacogenomics, Drug Intolerance and Clinical Relevance

Thiopurines such as azathioprine, 6-mercaptopurine and 6-thioguanine are antimetabolites that have been used for several decades in the treatment of several diseases including inflammatory bowel diseases. Additional anti-inflammatory properties of these thiopurines have been discovered in recent years. Thiopurine metabolism is complex due to the involvement of multiple enzymes, of which the activities are genetically determined and cell type dependent. Single nucleotide polymorphisms in the genes encoding these enzymes have been correlated with altered activities and drug intolerance. Detailed implications of these will be reviewed. Over the years several methods of therapeutic drug monitoring have been developed in an attempt to relate thiopurine drug availability with efficacy and intolerance. In this respect, monitoring pharmacologically active 6-thioguanine nucleotide concentrations is most widely used. So far, however, the clinical usefulness of these methods is hampered by methodological limitations. Some drug interactions may optimize the metabolization of thiopurines and consequently increase its efficacy and decrease drug intolerance. This review focuses on the clinical relevance and usefulness of therapeutic drug monitoring of thiopurines and provides suggestions to optimize thiopurine therapy in the treatment of inflammatory bowel diseases.

Multimodal treatment of perianal fistulas in Crohn’s disease: seton versus anti-TNF versus advancement plasty (PISA): study protocol for a randomized controlled trial

BackgroundCurrently there is no guideline for the treatment of patients with Crohn’s disease and high perianal fistulas. Most patients receive anti-TNF medication, but no long-term results of this expensive medication have been described, nor has its efficiency been compared to surgical strategies. With this study, we hope to provide treatment consensus for daily clinical practice with reduction in costs.Methods/DesignThis is a multicentre, randomized controlled trial. Patients with Crohn’s disease who are over 18 years of age, with newly diagnosed or recurrent active high perianal fistulas, with one internal opening and no anti-TNF usage in the past three months will be considered. Patients with proctitis, recto-vaginal fistulas or anal stenosis will be excluded. Prior to randomisation, an MRI and ileocolonoscopy are required. All treatment will start with seton placement and a course of antibiotics. Patients will then be randomised to: (1) chronic seton drainage (with oral 6-mercaptopurine (6MP)) for one year, (2) anti-TNF medication (with 6MP) for one year (seton removal after six weeks) or (3) advancement plasty after eight weeks of seton drainage (under four months anti-TNF and 6MP for one year). The primary outcome parameter is the number of patients needing fistula-related re-intervention(s). Secondary outcomes are the number of patients with closed fistulas (based on an evaluated MRI score) after 18 months, disease activity, quality of life and costs.DiscussionThe PISA trial is a multicentre, randomised controlled trial of patients with Crohn’s disease and high perianal fistulas. With the comparison of three generally accepted treatment strategies, we will be able to comment on the efficiency of the various treatment strategies, with respect to several long-term outcome parameters.Trial registrationNederlands Trial Register identifier: NTR4137 (registered on 23 August 2013).

The Prevalence of Nodular Regenerative Hyperplasia in Inflammatory Bowel Disease Patients Treated with Thioguanine Is Not Associated with Clinically Significant Liver Disease.

Background:Nodular regenerative hyperplasia (NRH) of the liver is associated with inflammatory-mediated diseases and certain drugs. There is conflicting data on the prevalence of NRH and its clinical implications in inflammatory bowel disease (IBD) patients treated with thioguanine. Methods:A retrospective cohort study involving 7 Dutch centers comprised all IBD patients who were being treated with thioguanine and underwent a liver biopsy as part of the standard toxicity screening. Liver biopsy specimens were reviewed by 2 experienced liver pathologists. Clinical data as well as liver chemistry, blood counts, and abdominal imaging were collected. Results:One hundred eleven IBD patients who submitted to liver biopsy were treated with thioguanine in a daily dose of 0.3 mg/kg for a median duration of 20 (4–64) months. NRH was detected in 6% of patients (7; 95% confidence interval, 3–14 patients). Older age (P = 0.02), elevated gamma-glutamyl transferase (P = 0.01) and alkaline phosphatase (P = 0.01) levels, a higher mean corpuscular volume (P = 0.02), and a lower platelet or leukocyte count (P < 0.01 and P = 0.02, respectively) were associated with NRH. Three of the 7 patients with NRH did not have any associated clinical symptoms or signs. The other 4 had minor biochemical abnormalities only. Ultrasonography revealed splenomegaly in 3 of the 78 patients (4%; 95% confidence interval, 0%–9%), only one of whom had NRH. There was no clinically overt portal hypertension. Conclusions:The prevalence of NRH was 6% in liver biopsies obtained from IBD patients treated with thioguanine. Histopathological irregularities including NRH were not associated with clinically significant findings over the period of observation.

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.

Golimumab for the treatment of ulcerative colitis

The introduction of therapeutic antibodies against tumor necrosis factor (TNF) had a major impact on the treatment of ulcerative colitis (UC). Infliximab and adalimumab are powerful agents that are used for remission induction and maintenance therapy in UC and have an acceptable safety profile. However, a proportion of UC patients for whom therapy with anti-TNF agents is indicated fail or become intolerant to treatment with infliximab or adalimumab. Hence, there remains an unmet need for novel anti-TNF agents. Golimumab (Simponi®), a human anti-TNF antibody that is administered by monthly subcutaneous injections, is the most recently introduced TNF blocker for the treatment of UC. Here, we will discuss recent literature on clinical efficacy and safety of golimumab induction and maintenance treatment in patients with UC. Furthermore, we will discuss the positioning of golimumab for UC in current treatment algorithms.