Long-term 6-mercaptopurine treatment in adolescents with Crohn's disease

Outcomes and Predictors of Sustained Remission After Drug Withdrawal in Pediatric Crohn Disease

OBJECTIVES

The primary aim of this study was to determine the proportion of pediatric Crohn disease (CD) subjects in sustained drug-free remission 52 weeks after stopping pharmacological therapy. We also aimed to explore the effects of the Crohn Disease Exclusion Diet (CDED) and microbiome composition on remission.

METHODS

We performed a prospective study following 18 CD patients ages 13-21 years in deep clinical remission withdrawing from immunomodulator (n = 7) or anti-TNFα (n = 11) monotherapy at two tertiary care centers. Stool for calprotectin and microbiome analyses was collected over 52 weeks. Participants followed either the CDED or free diet after drug withdrawal. The primary endpoint was sustained relapse-free drug-free remission (calprotectin <250 µg/g) at 52 weeks.

RESULTS

Seventeen participants were followed through 52 weeks with 11 (64.7%) in sustained remission. There was no improvement in remission among participants following the CDED (5/9; 55.6%), P = 0.63. By 104 weeks, only 8 (47.1 %) participants remained off immunosuppressive therapies. Analysis of shotgun metagenomic sequence data revealed that taxonomic and gene function abundance in the gut microbiome was relatively stable for participants in remission and relapse. However, a predictive model incorporating gut microbial gene pathway abundance for amino sugar/nucleotide sugar metabolism and galactose metabolism from baseline samples predicted relapse at 52 weeks with 80% accuracy.

CONCLUSIONS

After withdrawal of immunomodulator or anti-TNFα monotherapy among a small cohort of pediatric CD subjects in deep remission, nearly 65% sustained remission at 52 weeks. Baseline microbiome alterations predicted relapse. Large prospective studies are needed to better understand outcomes after treatment de-escalation.

Recommendations of the Crohn's Disease and Ulcerative Colitis Spanish Working Group (GETECCU) for the treatment of perianal fistulas of Crohn's disease

Recommendations are advice that is given and considered to be beneficial; however, they are still suggestions and are therefore open to different interpretations. In this sense, the final objective of the review has been to try to homogenize, with the evidence available, the approach to the diagnosis and medical/surgical treatment of one of the most complex manifestations of Crohn's disease, such as simple and complex perianal fistulas.

Azathioprine or 6-mercaptopurine for induction of remission in Crohn's disease

BACKGROUND

The results from controlled clinical trials investigating the efficacy of azathioprine and 6-mercaptopurine for the treatment of active Crohn's disease have been conflicting and controversial. An updated meta-analysis was performed to assess the effectiveness of these drugs for the induction of remission in active Crohn's disease.

OBJECTIVES

The primary objective was to determine the efficacy and safety of azathioprine and 6-mercaptopurine for induction of remission in active Crohn's disease.

SEARCH METHODS

We searched MEDLINE, EMBASE and the Cochrane Library from inception to 30 October 2015. Review articles and conference proceedings were also searched to identify additional studies.

SELECTION CRITERIA

Randomized controlled trials (RCTs) of oral azathioprine or 6-mercaptopurine compared to placebo or active therapy involving adult patients with active Crohn's disease were selected for inclusion.

DATA COLLECTION AND ANALYSIS

Data were extracted by two independent observers based on the intention-to-treat principle. Outcomes of interest included: clinical remission, clinical improvement, fistula improvement or healing, steroid sparing, adverse events, withdrawals due to adverse events and serious adverse events. We calculated the pooled relative risk (RR) and 95% confidence intervals (95% CI) for each outcome. The methodological quality of included studies was evaluated using the Cochrane risk of bias tool. The overall quality of the evidence supporting each outcome was assessed using the GRADE criteria.

MAIN RESULTS

Thirteen RCTs (n = 1211 patients) of azathioprine and 6-mercaptopurine therapy in adult patients were identified: nine included placebo comparators and six included active comparators. The majority of included studies were rated as low risk of bias. There was no statistically significant difference in clinical remission rates between azathioprine or 6-mercaptopurine and placebo. Forty-eight per cent (95/197) of patients receiving antimetabolites achieved remission compared to 37% (68/183) of placebo patients (5 studies, 380 patients; RR 1.23, 95% CI 0.97 to 1.55). There was no statistically significant difference in clinical improvement rates between azathioprine or 6-mercaptopurine and placebo. Forty-eight per cent (107/225) of patients receiving antimetabolites achieved clinical improvement or remission compared to 36% (75/209) of placebo patients (8 studies, 434 patients; RR 1.26, 95% CI 0.98 to 1.62). There was a statistically significant difference in steroid sparing (defined as prednisone dose < 10 mg/day while maintaining remission) between azathioprine and placebo. Sixty-four per cent (47/163) of azathioprine patients were able to reduce their prednisone dose to < 10 mg/day compared to 46% (32/70) of placebo patients (RR 1.34, 95% CI 1.02 to 1.77). GRADE analyses rated the overall quality of the evidence for the outcomes clinical remission, clinical improvement and steroid sparing as moderate due to sparse data. There was no statistically significant difference in withdrawals due to adverse events or serious adverse events between antimetabolites and placebo. Ten percent of patients in the antimetabolite group withdrew due to adverse events compared to 5% of placebo patients (8 studies, 510 patients; RR 1.70, 95% CI 0.94 to 3.08). Serious adverse events were reported in 14% of patients receiving azathioprine compared to 4% of placebo patients (2 studies, 216 patients; RR 2.57, 95% CI 0.92 to 7.13). Common adverse events reported in the placebo controlled studies included: allergic reactions. leukopenia, pancreatitis and nausea. Azathioprine was significantly inferior to infliximab for induction of steroid-free clinical remission. Thirty per cent (51/170) of azathioprine patients achieved steroid-free remission compared to 44% (75/169) of infliximab patients (1 study, 339 patients; RR 0.68, 95% CI 0.51 to 0.90). The combination of azathioprine and infliximab was significantly superior to infliximab alone for induction of steroid-free clinical remission. Sixty per cent (116/194) of patients in the combined azathioprine and infliximab group achieved steroid-free remission compared to 48% (91/189) of infliximab patients (2 studies, 383 patients; RR 1.23, 95% CI 1.02 to 1.47). Azathioprine or 6-mercaptopurine therapy was found to be no better at inducing steroid free clinical remission compared to methotrexate (RR 1.13, 95% CI 0.85 to 1.49) and 5-aminosalicylate or sulfasalazine (RR 1.24, 95% CI 0.80 to 1.91). There were no statistically significant differences in withdrawals due to adverse events between azathioprine or 6-mercaptopurine and methotrexate (RR 0.78, 95% CI 0.23 to 2.71); between azathioprine or 6-mercaptopurine and 5-aminosalicylate or sulfasalazine (RR 0.98, 95% CI 0.38 to 2.54); between azathioprine and infliximab (RR 1.47, 95% CI 0.96 to 2.23); or between the combination of azathioprine and infliximab and infliximab (RR 1.16, 95% CI 0.75 to 1.80). Common adverse events in the active comparator trials included nausea, abdominal pain, pyrexia and headache.

AUTHORS' CONCLUSIONS

Azathioprine and 6-mercaptopurine offer no advantage over placebo for induction of remission or clinical improvement in active Crohn's disease. Antimetaboilte therapy may allow patients to reduce steroid consumption. Adverse events were more common in patients receiving antimetabolites although differences with placebo were not statistically significant. Azathioprine therapy is inferior to infliximab for induction of steroid-free remission. However, the combination of azathioprine and infliximab was superior to infliximab alone for induction of steroid-free remission.

Review article: The pharmacokinetics and pharmacodynamics of drugs used in inflammatory bowel disease treatment

BACKGROUND

The following review is a compilation of the recent advances and knowledge on the behaviour of the most frequently used compounds to treat inflammatory bowel disease in an organism.

RESULTS

It considers clinical aspects of each entity and the pharmacokinetic/pharmacodynamic relationship supported by the use of plasma monitoring, tissue concentrations, and certain aspects derived from pharmacogenetics.

Azathioprine or 6-mercaptopurine for induction of remission in Crohn's disease

BACKGROUND

The results from controlled clinical trials investigating the efficacy of azathioprine and 6-mercaptopurine for the treatment of active Crohn's disease have been conflicting and controversial. An updated meta-analysis was performed to assess the effectiveness of these drugs for the induction of remission in active Crohn's disease.

OBJECTIVES

The primary objective was to determine the efficacy and safety of azathioprine and 6-mercaptopurine for induction of remission in active Crohn's disease.

SEARCH METHODS

A literature search for relevant studies (inception to June 13, 2012) was performed using MEDLINE, EMBASE and the Cochrane Library. Review articles and conference proceedings were also searched to identify additional studies.

SELECTION CRITERIA

Randomized controlled trials (RCTs) of oral azathioprine or 6-mercaptopurine compared to placebo or active therapy involving adult patients with active Crohn's disease were selected for inclusion.

DATA COLLECTION AND ANALYSIS

Data were extracted by two independent observers based on the intention-to-treat principle. Outcomes of interest included: clinical remission, clinical improvement, fistula improvement or healing, steroid sparing, adverse events, withdrawals due to adverse events and serious adverse events. We calculated the pooled relative risk (RR) and 95% confidence intervals (95% CI) for each outcome. The methodological quality of included studies was evaluated using the Cochrane risk of bias tool. The overall quality of the evidence supporting each outcome was assessed using the GRADE criteria.

MAIN RESULTS

Thirteen RCTs (n = 1211 patients) of azathioprine and 6-mercaptopurine therapy in adult patients were identified: nine included placebo comparators and six included active comparators. The majority of included studies were rated as low risk of bias. There was no statistically significant difference in clinical remission rates between azathioprine or 6-mercaptopurine and placebo. Forty-eight per cent (95/197) of patients receiving antimetabolites achieved remission compared to 37% (68/183) of placebo patients (5 studies, 380 patients; RR 1.23, 95% CI 0.97 to 1.55). There was no statistically significant difference in clinical improvement rates between azathioprine or 6-mercaptopurine and placebo. Forty-eight per cent (107/225) of patients receiving antimetabolites achieved clinical improvement or remission compared to 36% (75/209) of placebo patients (8 studies, 434 patients; RR 1.26, 95% CI 0.98 to 1.62). There was a statistically significant difference in steroid sparing (defined as prednisone dose < 10 mg/day while maintaining remission) between azathioprine and placebo. Sixty-four per cent (47/163) of azathioprine patients were able to reduce their prednisone dose to < 10 mg/day compared to 46% (32/70) of placebo patients (RR 1.34, 95% CI 1.02 to 1.77). GRADE analyses rated the overall quality of the evidence for the outcomes clinical remission, clinical improvement and steroid sparing as moderate due to sparse data. There was no statistically significant difference in withdrawals due to adverse events or serious adverse events between antimetabolites and placebo. Ten percent of patients in the antimetabolite group withdrew due to adverse events compared to 5% of placebo patients (8 studies, 510 patients; RR 1.70, 95% CI 0.94 to 3.08). Serious adverse events were reported in 14% of patients receiving azathioprine compared to 4% of placebo patients (2 studies, 216 patients; RR 2.57, 95% CI 0.92 to 7.13). Common adverse events reported in the placebo controlled studies included: allergic reactions. leukopenia, pancreatitis and nausea. Azathioprine was significantly inferior to infliximab for induction of steroid-free clinical remission. Thirty per cent (51/170) of azathioprine patients achieved steroid-free remission compared to 44% (75/169) of infliximab patients (1 study, 339 patients; RR 0.68, 95% CI 0.51 to 0.90). The combination of azathioprine and infliximab was significantly superior to infliximab alone for induction of steroid-free clinical remission. Sixty per cent (116/194) of patients in the combined azathioprine and infliximab group achieved steroid-free remission compared to 48% (91/189) of infliximab patients (2 studies, 383 patients; RR 1.23, 95% CI 1.02 to 1.47). Azathioprine or 6-mercaptopurine therapy was found to be no better at inducing steroid free clinical remission compared to methotrexate (RR 1.13, 95% CI 0.85 to 1.49) and 5-aminosalicylate or sulfasalazine (RR 1.24, 95% CI 0.80 to 1.91). There were no statistically significant differences in withdrawals due to adverse events between azathioprine or 6-mercaptopurine and methotrexate (RR 0.78, 95% CI 0.23 to 2.71); between azathioprine or 6-mercaptopurine and 5-aminosalicylate or sulfasalazine (RR 0.98, 95% CI 0.38 to 2.54); between azathioprine and infliximab (RR 1.47, 95% CI 0.96 to 2.23); or between the combination of azathioprine and infliximab and infliximab (RR 1.16, 95% CI 0.75 to 1.80). Common adverse events in the active comparator trials included nausea, abdominal pain, pyrexia and headache.

AUTHORS' CONCLUSIONS

Azathioprine and 6-mercaptopurine offer no advantage over placebo for induction of remission or clinical improvement in active Crohn's disease. Antimetaboilte therapy may allow patients to reduce steroid consumption. Adverse events were more common in patients receiving antimetabolites although differences with placebo were not statistically significant. Azathioprine therapy is inferior to infliximab for induction of steroid-free remission. However, the combination of azathioprine and infliximab was superior to infliximab alone for induction of steroid-free remission.

Biological immunomodulators improve the healing rate in surgically treated perianal Crohn's fistulas

AIM

The role of biological therapy in perianal fistulas associated with Crohn's disease (CD) is uncertain as available data are confused and conflicting. In order to provide some clarity to the issue we have examined a large cohort of patients with perianal fistulas and CD and stratified them according to use of biological agents.

METHOD

Patients with perianal Crohn's fistulas treated between June 1999 and June 2009 were stratified according to use of biological agents and outcome was examined. Healing was defined as absence of fistula or drainage. Prior to surgery perianal sepsis was eradicated with drains or setons. Endpoints were defined as either complete healing, improvement (minimal symptoms and drainage) or unhealed, as noted at subsequent outpatient follow-up. Variables assessed were age, body mass index, smoking, perineal involvement with Crohn's granuloma and type of procedure. Fisher's exact test and χ(2) test were used for analysis.

RESULTS

Two hundred and eighteen patients had anal fistulas and CD. Mean follow-up was 3.2±3 years with mean age 38.8±12.2years and body mass index of 25.3±6. One hundred and seventeen patients (53.7%) underwent surgery alone (Group A) and 101 patients (46.3%) underwent surgery and biological immunomodulator treatments (Group B). Demographic data and CD history were similar between groups. Surgeries included seton drainge (n=90), fistulotomy (n=22), rectal advancement flap (n=39), fistulotomy plus seton (n=47) and others (n=20). Overall improvement in Group A was in 42 patients (35.9%) vs 72 patients (71.3%) in Group B (P=0.001). There was no significant difference in other studied variables between both groups.

CONCLUSIONS

There is a definite role for biological therapy as an adjuvant to surgery in patients with perianal fistulas and CD.

Identifying youth nonadherence in clinical settings: data-based recommendations for children and adolescents with inflammatory bowel disease

BACKGROUND

To examine the validity of patient self-report of thiopurine adherence in pediatric inflammatory bowel disease (IBD) against an objective electronic monitoring adherence measure, and to investigate the role of youth and maternal involvement in remembering to take daily medications as predictors of medication adherence.

METHODS

Fifty-one youths with IBD, ages 11-18 years, participated. Youths completed questionnaire assessments of their own and their maternal caregiver's involvement in remembering to take daily medications at baseline, completed monthly interviews assessing thiopurine adherence over the past week for a period of 6 months, and utilized a Medication Events Monitoring System (MEMS) electronic monitor for their thiopurine medication for 6 months. Participants were grouped into adherent (at least 80% of doses taken based on objective MEMS caps) or nonadherent for analyses.

RESULTS

Youths who were nonadherent based on electronic monitoring overestimated their adherence by 23%, whereas adherent youths overestimated their adherence by only 2%, and as such patient self-report offered little utility in identifying youths who were nonadherent. Youths who reported high levels of involvement in remembering to take their medications were nearly eight times less likely to be nonadherent.

CONCLUSIONS

The current findings provide evidence that clinicians who work with children and adolescents with IBD may benefit from modifying their approach to nonadherence screening. Asking about youth involvement in remembering daily medications may be more informative than asking them to recall their medication-taking behavior over the last week in identifying those at highest risk for nonadherence.

Biologics in paediatric Crohn's disease

Crohn's disease affects increasing numbers of children worldwide. Generally, childhood-onset disease runs a more severe course than in adults and has a greater impact on quality of life. Therapy in children must take account of a different set of risks for toxicity compared to adults, but also to their longevity. Biologic drugs present remarkable advantages in terms of disease control for children, especially in those whose disease cannot be controlled with conventional therapies, but their long-term risks are still being assessed. Data regarding biologic use in children is limited and mostly amounts to case series, but results have been promising, both in terms of controlling disease activity and improving growth parameters. Adverse reactions are infrequent in the short term, but loss of response is a long-term problem, particularly in children. More information is needed about very long term risks. Infliximab and adalimumab are the most studied agents in children, while there is relatively limited data on certolizumab and natalizumab. Further collection of data on these agents is still needed, but this should not restrict access to these agents for children in whom no other agent is effective.

Association of Crohn's disease, thiopurines, and primary epstein-barr virus infection with hemophagocytic lymphohistiocytosis

OBJECTIVE

To assess the incidence of hemophagocytic lymphohistiocytosis (HLH) in a well-defined population of children with inflammatory bowel disease (IBD) and evaluate the common clinical and laboratory characteristics of individuals with IBD who developed HLH.

STUDY DESIGN

We conducted a retrospective study of all children who developed HLH over an 8-year period. The incidence of HLH in patients with IBD was calculated using US census data and a statewide project examining the epidemiology of pediatric IBD.

RESULTS

Among children in Wisconsin, 20 cases of HLH occurred during the study period; 5 cases occurred in children with IBD. Common characteristics include: Crohn's disease (CD), thiopurine administration, fever lasting more than 5 days, lymphadenopathy, splenomegaly, anemia, lymphopenia, and elevated serum triglycerides and ferritin. Of the patients, 4 had primary Epstein-Barr virus infections. The incidence of HLH among all children in Wisconsin was 1.5 per 100 000 per year. The risk was more than 100-fold greater for children with CD (P < .00001).

CONCLUSIONS

Pediatric patients with CD are at increased risk for developing HLH; primary Epstein-Barr virus infection and thiopurine administration may be risk factors.

Relapse rate following azathioprine withdrawal in maintaining remission for Crohn's disease: a meta-analysis

BACKGROUND

The duration of use of azathioprine (Aza) and 6-mercaptopurine (6-MP) for maintaining remission for Crohn's disease is debatable.

AIM

To examine whether Aza/6-MP can be safely withdrawn in patients with Crohn's disease who have been in remission.

METHODS

The following databases were searched: MEDLINE (1950-September 2010), EMBASE (1980-September 2010), CINHAL (1981-September 2010), PubMed (1950-September 2010), and the Cochrane Central Register of Controlled Trials (CENTRAL). Randomised controlled and cohort studies comparing azathioprine continuation versus placebo or no treatment were eligible for inclusion. Primary outcomes were relapse rate after discontinuation of Aza/6-MP at 6, 12, and 18 months, and 5 and 10 years.

RESULTS

Five studies, with 256 patients and 168 controls, met the inclusion criteria. Stopping azathioprine/6-MP was found to significantly increase the risk of relapse at 6, 12, and 18 months with pooled odds ratios of 0.22 (95% CI 0.09-0.53), 0.25 (95% CI 0.11-0.56), and 0.35 (95% CI 0.21-0.6), respectively. Two trials examined relapse rate at 5 years with pooled OR 0.53 (95% CI 0.13-2.21). No trials looking at relapse rates beyond 5 years were identified.

CONCLUSIONS

There is a clear benefit of continuing Aza/6-MP for at least 18 months to maintain remission for Crohn's disease patients who established remission. There is not enough evidence to provide clear guidance on whether or not to continue Aza/6-MP treatment beyond 18 months. Well-designed randomised controlled trials addressing this issue are needed.

Nonfistulizing perianal Crohn's disease: clinical features, epidemiology, and treatment

Nonfistulizing perianal lesions, including ulcerations, strictures, and anal carcinoma, are frequently observed in Crohn's disease. Their clinical course remains poorly known. The management of these lesions is difficult because none of the treatments used is evidence-based. Ulcerations may be symptomatic in up to 85% of patients. Most ulcerations heal spontaneously but may also progress to anal stenosis or fistula/abscess. Topical treatments only improve symptoms, while complete healing can occur in patients with perianal ulcerations receiving infliximab therapy. Half of all patients with anal strictures will require permanent fecal diversion. Dilatation for symptomatic strictures should be performed on a highly selective basis in the absence of active rectal disease in order to avoid infectious complications. Anorectal strictures associated with rectal lesions should first be managed with medical therapy. Skin tags are usually painless and may hide other perianal lesions. Anal cancer is uncommon. Its treatment is similar to that recommended for anal cancer occurring in non-Crohn's disease patients. After reviewing the classification, clinical features, and epidemiology of each type of nonfistulizing perianal lesion (ulceration, stricture, skin tags, and anal cancer), we discuss the efficacy of medical treatment and surgery. This review article may help physicians in decision-making when managing potentially disabling lesions.

Inflammatory bowel disease in children: current trends

Once considered rare in the East, inflammatory bowel disease (IBD) is now recognized to be an emerging entity in that region. East or West, the clinical features of and treatment options for IBD are the same, but it is possible that the exact pathogeneses or the initiating events differ. In this review, existing knowledge of IBD and new discoveries in the epidemiology, genetics and treatment of IBD are discussed in detail. The diagnosis and management of IBD in children has changed dramatically over the last decade, mainly due to increased awareness, the availability of newer diagnostic modalities such as MRI and video capsule endoscopy, and newer, more powerful treatments such as biologics. It is hoped that the combination of innovative research and advances in drug discoveries will change the natural history of IBD and make a major difference in children who are suffering from this unfortunate lifelong chronic inflammatory disorder.

Azathioprine or 6-mercaptopurine for induction of remission in Crohn's disease

BACKGROUND

The results from controlled clinical trials investigating the efficacy of azathioprine and 6-mercaptopurine for the treatment of active Crohn's disease were conflicting and controversial. A meta-analysis was performed to assess the effectiveness of these drugs for the induction of remission in active Crohn's disease.

OBJECTIVES

To determine the effectiveness of azathioprine and 6-mercaptopurine in inducing remission of active Crohn's disease.

SEARCH STRATEGY

Studies were selected using the MEDLINE database (1966 to July 2009), abstracts from major gastrointestinal meetings and references from published articles and review. The Cochrane Trials Register and the Inflammatory Bowel Disease Review Group Trials Register were also searched. This search strategy was updated using the MEDLINE, EMBASE and the International Pharmaceutical Abstracts databases as well as the Cochrane Register of Controlled Trials and the Cochrane IBD/FBD group Specialized Trials Register.

SELECTION CRITERIA

Randomized, double-blind, placebo-controlled trials of oral azathioprine or 6-mercaptopurine involving adult patients (> 18 years) with active Crohn's disease were selected for inclusion.

DATA COLLECTION AND ANALYSIS

Data were extracted by three independent observers based on the intention to treat principle. Each study was given a quality score based on predetermined criteria. Extracted data were converted to 2X2 tables (response versus no response and antimetabolite versus placebo) and then synthesized into a summary test statistic using the pooled odds ratio and 95% confidence intervals as described by Cochran and Mantel and Haenszel.

MAIN RESULTS

Eight randomized placebo controlled trials of azathioprine and 6-mercaptopurine therapy in adult patients were identified: five dealt with active disease and three had multiple therapeutic arms. The odds ratio (OR) of a response to azathioprine or 6-mercaptopurine therapy compared with placebo in active Crohn's disease was 2.43 (95% CI 1.62 to 3.64). This corresponded to a number needed to treat (NNT) of about 5 to observe an effect of therapy in one patient. When the two trials using 6-mercaptopurine in active disease were excluded from the analysis, the OR was 2.06 (95% CI 1.25 to 3.39). Treatment of > 17 weeks resulted in an OR of 2.61 (95% CI 1.69 to 4.03). A steroid sparing effect was seen with an OR of 3.69 (95% CI 2.12 - 6.42), corresponding to a NNTof about 3 to observe steroid sparing in one patient. Adverse events requiring withdrawal from a trial, principally allergy, leukopenia, pancreatitis, and nausea were increased with active therapy with an odds ratio of 3.44 (95% CI 1.52 to 7.77). The NNT to observe one adverse event in one patient treated with azathioprine or 6-mercaptopurine was 14.

AUTHORS' CONCLUSIONS

Azathioprine and 6-mercaptopurine are effective therapy for inducing remission in active Crohn's disease. Adverse events were more common among patients on active therapy.

Systematic review of the evidence base for the medical treatment of paediatric inflammatory bowel disease

OBJECTIVE

To systematically review the evidence base for the medical (pharmaceutical and nutritional) treatment of paediatric inflammatory bowel disease.

METHODS

Key clinical questions were formulated regarding different treatment modalities used in the treatment of paediatric (not adult-onset) IBD, in particular the induction and maintenance of remission in Crohn disease and ulcerative colitis. Electronic searches were performed from January 1966 to December 2006, using the electronic search strategy of the Cochrane IBD group. Details of papers were entered on a dedicated database, reviewed in abstract form, and disseminated in full for appraisal. Clinical guidelines were appraised using the AGREE instrument and all other relevant papers were appraised using Scottish Intercollegiate Guidelines Network methodology, with evidence levels given to all papers.

RESULTS

A total of 6285 papers were identified, of which 1255 involved children; these were entered on the database. After critical appraisal, only 103 publications met our criteria as evidence on medical treatment of paediatric IBD. We identified 3 clinical guidelines, 1 systematic review, and 16 randomised controlled trials; all were of variable quality, with none getting the highest methodological scores.

CONCLUSIONS

This is the first comprehensive review of the evidence base for the treatment of paediatric IBD, highlighting the paucity of trials of high methodological quality. As a result, the development of clinical guidelines for managing children and young people with IBD must be consensus based, informed by the best-available evidence from the paediatric literature and high-quality data from the adult IBD literature, together with the clinical expertise and multidisciplinary experience of paediatric IBD experts.

Azathioprine or 6-mercaptopurine for induction of remission in Crohn's disease

BACKGROUND

The results from controlled clinical trials investigating the efficacy of azathioprine and 6-mercaptopurine for the treatment of active Crohn's disease were conflicting and controversial. A meta-analysis was performed to assess the effectiveness of these drugs for the induction of remission in active Crohn's disease.

OBJECTIVES

To determine the effectiveness of azathioprine and 6-mercaptopurine in inducing remission of active Crohn's disease.

SEARCH STRATEGY

Studies were selected using the MEDLINE database (1966 to July 2009), abstracts from major gastrointestinal meetings and references from published articles and review. The Cochrane Trials Register and the Inflammatory Bowel Disease Review Group Trials Register were also searched. This search strategy was updated using the MEDLINE, EMBASE and the International Pharmaceutical Abstracts databases as well as the Cochrane Register of Controlled Trials and the Cochrane IBD/FBD group Specialized Trials Register.

SELECTION CRITERIA

Randomized, double-blind, placebo-controlled trials of oral azathioprine or 6-mercaptopurine involving adult patients (> 18 years) with active Crohn's disease were selected for inclusion.

DATA COLLECTION AND ANALYSIS

Data were extracted by three independent observers based on the intention to treat principle. Each study was given a quality score based on predetermined criteria. Extracted data were converted to 2X2 tables (response versus no response and antimetabolite versus placebo) and then synthesized into a summary test statistic using the pooled odds ratio and 95% confidence intervals as described by Cochran and Mantel and Haenszel.

MAIN RESULTS

Eight randomized placebo controlled trials of azathioprine and 6-mercaptopurine therapy in adult patients were identified: five dealt with active disease and three had multiple therapeutic arms. The odds ratio (OR) of a response to azathioprine or 6-mercaptopurine therapy compared with placebo in active Crohn's disease was 2.43 (95% CI 1.62 to 3.64). This corresponded to a number needed to treat (NNT) of about 5 to observe an effect of therapy in one patient. When the two trials using 6-mercaptopurine in active disease were excluded from the analysis, the OR was 2.06 (95% CI 1.25 to 3.39). Treatment > 17 weeks increased the OR to 2.61 (95% CI 1.69 to 4.03). A steroid sparing effect was seen with an OR of 3.69 (95% CI 2.12 - 6.42), corresponding to a NNTof about 3 to observe steroid sparing in one patient. Adverse events requiring withdrawal from a trial, principally allergy, leukopenia, pancreatitis, and nausea were increased with active therapy with an odds ratio of 3.44 (95% CI 1.52 to 7.77). The NNT to observe one adverse event in one patient treated with azathioprine or 6-mercaptopurine was 14.

AUTHORS' CONCLUSIONS

Azathioprine and 6-mercaptopurine are effective therapy for inducing remission in active Crohn's disease. The OR of response increases after > 17 weeks of therapy, suggesting that there is a minimum length of time for a trial of azathioprine or 6-mercaptopurine therapy. Adverse events were more common among patients on active therapy.

Predicting factors of fistula healing and clinical remission after infliximab-based combined therapy for perianal fistulizing Crohn's disease

Perianal fistulizing Crohn's disease (PFCD) treatment is based on fistula drainage, antibiotics, immunosuppressant (IS) drugs, and infliximab. Our aim was to study the effectiveness of combination therapy on PFCD and to search for clinical or imaging features associated with the initial complete clinical response and its stability overtime.

PATIENTS AND METHODS

All patients with PFCD treated in our tertiary center between 2000 and 2005 by infliximab in combination with seton placement and/or IS and evaluated by MRI before treatment were included in the study. Basal clinical and MRI characteristics were recorded. Response to treatment was evaluated after the infliximab induction regiment and at the end of the follow-up.

RESULTS

Twenty-six patients were included and followed-up for an average 4.9 years. A complex fistula was present in 69% (18/26 patients) of cases and eight (8/26 patients) had an ano-vaginal fistula. After infliximab induction therapy, 13 patients (50%) achieved a complete clinical response. The initial clinical response was significantly associated with the absence of both, active intestinal disease (54% vs. 8%, P = 0.03) and active proctitis (77% vs. 23%, P = 0.01). No initial MRI characteristics were linked to the initial response. In multivariate analysis, only the presence of active proctitis was associated with the lack of response (P = 0.047). At the end of the follow-up, 42% of the patients remained in clinical remission. No clinical characteristics were associated to sustained response when among long-standing responders two exhibited a normal post-treatment MRI.

CONCLUSION

An initial complete response of PFCD was observed in half of the patients after combined therapy including infliximab that decreased to 42% later on. Complete healing of fistulas on MRI was possible but unusual. The initial response seemed related to the absence of active intestinal disease, especially in the rectum, when the long-term response could not be predicted by the basal characteristics of patients.

Infliximab therapy in children with concurrent perianal Crohn disease: observations from REACH

OBJECTIVE

Post hoc analyses evaluated the effect of infliximab upon concurrent perianal Crohn disease (CD) in a subpopulation of 31 patients from REACH, a randomized trial of 112 children with moderately to severely active luminal CD.

MATERIALS AND METHODS

The Pediatric Crohn Disease Activity Index perirectal subscore was used to assess perianal symptom activity and therapeutic response. Patients with no symptoms or asymptomatic tags received a score of 0; those with "1-2 indolent fistula, scant drainage, no tenderness" received a score of 5; and those with "active fistula, drainage, tenderness or abscess" received a score of 10. Initial perirectal subscores of 10 or 5 decreasing to 0 were considered complete response. Subscores of 10 decreasing to 5 were considered partial response. All patients were followed for efficacy and safety through week 54.

RESULTS

Twenty-two patients with baseline perianal disease were randomized at week 10 following a 3-dose infliximab induction regimen. At week 2, 40.9% (9/22) of patients with signs and symptoms of perianal disease at baseline attained response (4 partial and 5 complete). At week 54, 72.7% (16/22) of patients with signs and symptoms of perianal disease attained response (1 partial and 15 complete). Nine patients developed perianal signs and symptoms during treatment; 7 had complete response and 2 had no response at week 54. The incidence of adverse events for patients with perianal symptoms at baseline and for those in the overall REACH population was similar (95.7% vs 94.6%).

CONCLUSIONS

Infliximab rapidly reduced concurrent perianal disease signs and symptoms in this REACH cohort.

Does infliximab infusion impact results of operative treatment for Crohn's perianal fistulas?

PURPOSE

Infliximab is an effective treatment for active intestinal Crohn's disease; however, the efficacy of infliximab in perianal Crohn's disease is controversial. This study was designed to compare patients with Crohn's disease who underwent perianal fistula surgery with or without infliximab infusion.

METHODS

A retrospective chart review of 226 consecutive patients with Crohn's disease who underwent operative treatment with or without infliximab (3-6 infusions of 5 mg/kg) from March 1991 through December 2005 was completed. Patients were classified as completely healed, minimally symptomatic (seton placement with minimal drainage and/or infliximab dependence), and failure (persistent or recurrent symptomatic fistula, diverting procedure, or proctectomy).

RESULTS

A total of 226 patients underwent operative treatment alone (n = 147) or in combination with infliximab infusion (n = 79). Age, gender, and preoperative history of intestinal and perianal Crohn's disease were similar between groups. Mean follow-up was 30 (range, 6-216) months. Operative treatment consisted of seton drainage (n = 112), conventional fistulotomy (n = 92), fibrin glue injection (n = 14), advancement flap (n = 5), collagen plug insertion (n = 2), and transperineal repair (n = 1). Eighty-eight patients (60 percent) healed completely with operative treatment alone, and 47 patients (59 percent) healed after operative treatment in combination with infliximab (P = not significant).

CONCLUSIONS

Operative treatment of perianal fistulas in patients with Crohn's disease resulted in complete healing in approximately 60 percent of patients. Preoperative infliximab infusion did not affect overall healing rates.

Medical options for treating perianal Crohn's disease

Perianal Crohn's disease can cause significant morbidity for patients affected by the disease. However, diagnostic modalities and treatment options have progressed changing the goals of treatment from fistula "improvement" to complete cessation of drainage. Fistula closure and fibrosis of the fistula track is achieved in some patients. Furthermore, treatment has become a combined effort between medical physicians and surgeons. Simple disease can be treated with medical therapy alone consisting of antibiotics and immunomodulators. Infliximab should be added to refractory simple disease or simple disease with the presence of inflammation. If complex fistula disease is evident a surgical evaluation should also be done to determine if intervention is indicated. Complex disease should be treated with antibiotics, immunomodulators and biologic therapy from the onset. This review will summarise current data regarding medical options for treatment of fistulising Crohn's disease.

Perianal Crohn's disease

Perianal Crohn's disease in children is a potentially debilitating condition that can precede or follow the intestinal disease component. The perianal abnormalities are varied and can include lesions of the perianal skin or anal canal, abscesses or fistulas, and malignancies. The appropriate management of these problems is predicated on a thorough evaluation of the perineum and anus as well as the remainder of the alimentary tract. Therapy usually includes a combination of antibiotics, immunomodulators, and biologic agents as well as conservative operative procedures. The surgical options are intended to safely ameliorate disease-related symptoms without compromising function or continence.

Topical tacrolimus in the treatment of perianal Crohn's disease: exploratory randomized controlled trial

BACKGROUND

The aim of this study is to evaluate the efficacy of topical tacrolimus in treating perianal Crohn's disease.

METHODS

Nineteen patients, stratified into 7 with ulcerating, and 12 with fistulizing, perianal Crohn's disease were randomized to topical tacrolimus 1 mg/g (1 g ointment twice a day [bid]) or placebo for 12 weeks. Sixteen patients had been on, or were currently taking, azathioprine/6-MP, and 6 had received infliximab. The primary outcome in ulcerating disease was global improvement in perianal/anal lesions, as assessed by the attending physician; for fistulas, it was reduction of > or =50% of actively draining fistulas on 2 consecutive visits. Blood tacrolimus levels and adverse events were assessed.

RESULTS

Three of 4 patients treated with topical tacrolimus for ulcerating disease improved compared with none of 3 in the placebo group. Complete healing was not achieved. In fistulizing disease, topical tacrolimus was not beneficial. Two tacrolimus-treated patients developed perianal abscesses, 1 after improvement in fistula drainage. Adverse events were otherwise infrequent and mild. Whole blood tacrolimus levels were detectable in only 2 patients and were low.

CONCLUSIONS

These preliminary data suggest that topical tacrolimus is effective and safe in the treatment of perianal or anal ulcerating Crohn's disease. This therapy is unlikely to be beneficial in fistulizing perianal Crohn's disease, although a larger study is required to confirm this.

Current therapy of inflammatory bowel disease in children

Ulcerative colitis (UC) and Crohn disease (CD) are chronic intestinal inflammatory diseases that can present as bloody diarrhea, abdominal pain, and malnutrition. Collectively, these disorders are referred to as inflammatory bowel disease (IBD). All patients with IBD share a common pathophysiology. However, there are a number of developmental, psychosocial, and physiologic issues that are unique to the approximate, equals 20% of patients that present during childhood or adolescence. These include the possibility of disease-induced delays in linear growth or physical development, differences in drug dosing, and the changes in social and cognitive development that occur as children move from school-age years into adolescence and early adulthood. Gastroenterologists caring for these children must therefore develop an optimal regimen of pharmacologic therapies, nutritional management, psychologic support, and properly timed surgery (when necessary) that will maintain disease remission, minimize disease and drug-induced adverse effects, and optimize growth and development. This article reviews current approaches to the management of patients with UC and CD and highlights issues specific to the treatment of children with IBD. The principal medical therapies used to induce disease remission in patients with UC are aminosalicylates (for mild disease), corticosteroids (for moderate disease), and cyclosporine (ciclosporin) (for severe disease). If a patient responds to the induction regimen, maintenance therapies that are used to prevent disease relapse include aminosalicylates, mercaptopurine, and azathioprine. Colectomy with creation of an ileal pouch anal anastomosis (J pouch) has become the standard of care for patients with severe or refractory colitis and results in an improved quality of life in most patients. Therefore, the risks associated with using increasingly potent immunosuppressant agents must be balanced in each case against a patient's desire to retain their colon and avoid a temporary or potentially permanent ileostomy. Decisions about drug therapy in the management of patients with CD are more complex and depend on both the location (e.g. gastroduodenal vs small intestinal vs colonic), as well as the behavior of the disease (inflammatory/mucosal vs stricturing vs perforating) in a given patient. Induction therapies for CD typically include aminosalicylates and antibiotics (for mild mucosal disease), nutritional therapy (including elemental or polymeric formulas), corticosteroids (for moderate disease), and infliximab (for corticosteroid-resistant or fistulizing disease). Aminosalicylates, mercaptopurine, azathioprine, methotrexate, and infliximab can be used as maintenance therapies. Because surgical treatment of CD is not curative, it is typically reserved for those patients either with persistent symptoms and disease limited to a small section of the intestine (e.g. the terminal ileum and cecum) or for the management of complications of the disease including stricture or abdominal abscess. When surgery is necessary, maintenance medications administered postoperatively will postpone recurrence. Patients with UC and CD are at risk for the development of micronutrient deficiencies (including folate, iron, and vitamin D deficiencies) and require close nutritional monitoring. In addition, patients with UC and CD involving the colon are at increased risk of developing colon cancer, and should be enrolled into a colonoscopy surveillance program after 8-10 years of disease duration.

Infliximab in fistulizing Crohn's disease

The treatment of fistulizing CD has evolved greatly in the last 15 years, largely caused by improvements in medical therapy. Tables 2 and 3 summarize all published controlled and uncontrolled trials of immunomodulator and biologic therapy for the treatment of Crohn's fistulae. The advent of immunomodulators and anti-TNF-alpha agents has transformed the treatment of Crohn's fistulae from almost exclusively surgical to placing a much larger emphasis on medical therapy, either as initial therapy alone, with surgery reserved for refractory cases, or in combination with surgery from the start. For this reason, surgeons and gastroenterologists must work in concert to provide the best care for each patient. Proper fistula management also relies heavily on accurate diagnosis, especially defining the anatomy of the fistula, ascertaining whether abscess formation is present, and determining the location and extent of intestinal inflammation.

Predictors of immunomodulator use as early therapy in pediatric Crohn's disease

GOALS

The goals of this study were to identify markers in a patient's presentation and disease progression that predict the need for the use of immunomodulators in a pediatric population.

BACKGROUND

Although immunomodulator safety and efficacy have been documented in Crohn's disease, models for predicting outcome and the need for immunomodulators (azathioprine, 6-mercaptopurine, or methotrexate) early in the disease course have not been investigated in children or adults.

METHODS

Data on newly diagnosed Crohn's disease patients were prospectively collected within 3 weeks of diagnosis, 6 months after diagnosis, and 1 year after diagnosis. Information collected at each visit included medication use and disease activity assessment.

RESULTS

A total of 57 patients who were followed for > or = 6 months were evaluated. Overall, 34 of 57 (59.6%) were started on immunomodulators within 1 year of diagnosis. Mean serum albumin (3.35 g/dL vs. 3.7 g/dL, P = 0.013) and hematocrit (33.3% vs. 35.9%, P = 0.023) at diagnosis were lower, and erythrocyte sedimentation rate (32 vs. 12, P = 0.011) at diagnosis was higher in patients who required immunomodulators. The total Pediatric Crohn's Disease Activity Index score as well as the physical examination score and patient recall score within the PCDAI at diagnosis were not different among those who received immunomodulators and those that did not.

CONCLUSIONS

Immunomodulators are frequently used within 1 year of diagnosis in pediatric Crohn's disease. Lower serum albumin levels and hematocrit, and elevated erythrocyte sedimentation rate at diagnosis may predict the need for immunomodulators earlier in the disease course.

Long-term healing of Crohn's anal fistulas with fibrin glue injection

BACKGROUND

Injecting fibrin glue has proved to be an effective means of treating anal fistulas (AF). There has been some debate, however, as to whether this technique should be used on the AF often involved in Crohn's disease (CD).

AIM

To assess the effectiveness of injecting heterologous fibrin glue as a means of treating AF refractory to immunosuppressive treatment in patients with CD.

METHODS

Fourteen CD patients (five men and nine women, average age 42 years) presenting with refractory AFs were included in this study. Heterologous fibrin glue was injected into the fistula tract under general anaesthesia under continuous endosonographic monitoring using a 7.5-MHz blind linear probe. The patients were followed up clinically and ultrasonographically for 3 months after the procedure, and then at regular intervals.

RESULTS

Three months after the fibrin glue injection, the fistulas had completely dried up in 10 patients (71%), the leakage had decreased in one patient (7%), and no improvement was observed in the other three patients (21%). Endosonographic findings showed that the fistula tract had completely disappeared in two cases (14%). The fistula tract was found to be non-permeable in eight cases (57%), and no change in the fistula was observed in four patients (29%). At the end of the follow-up period [average 23.4 months (12-26 months)], the leakage had completely dried up in eight of the 14 patients (57%). No side effects were observed.

CONCLUSION

Nearly 2 years after the use of a heterologous fibrin glue to treat an AF, over half of the patients with CD showed clinical signs of remission. Because it is easy to use and harmless as well as being effective, this method provides a good alternative to classical methods of surgical treatment.

Can we alter the natural history of Crohn disease in children?

The natural history of Crohn disease is characterized by recurrent bouts of active disease, the consequences of which can severely impair sufferers' physical and social functioning. Not only does the illness cause day-to-day morbidity for children but the consequence of the chronic inflammatory process also commonly results in the need for major intestinal surgery. The present challenge facing physicians treating children with Crohn disease is to alleviate symptoms and prolong periods of remission via the use of specifically targeted therapies while minimizing toxicity and promoting normal growth and development. Although systemic corticosteroids are effective in inducing clinical remission, they are of little or no benefit in maintaining remission and can contribute to linear growth retardation. Immunomodulating drugs such as azathioprine, 6-mercaptopurine and methotrexate have proved effective for inducing and maintaining remission of active Crohn disease. These agents are now commonly prescribed in children at diagnosis, after a severe attack or after surgery or in those who become corticosteroid-dependent or corticosteroid-resistant. Their use is not without potential adverse effects and not all patients respond well to these agents. With the introduction of biologic agents, notably the tumor necrosis factor-alpha monoclonal antibody infliximab, progress has been made in targeting specific pathogenetic mechanisms of Crohn disease and potentially altering the underlying disease process. Published experience in children is currently limited, but infliximab has been shown to improve symptoms and achieve corticosteroid independence in this age group. Unresolved issues with infliximab and other emerging biologic agents, including long-term safety, necessitate a degree of caution in selecting appropriate patients for treatment and with careful monitoring of their effects. The collection of contemporary natural history data is crucial to facilitate the better integration of current and emerging therapies in an attempt to alter the natural history of Crohn disease in children.

Perianal Crohn's disease

BACKGROUND

The management of perianal Crohn's disease is difficult. A wide variety of treatment options exist although few are evidence based.

METHODS

A search was conducted using the National Library of Medicine for articles on perianal Crohn's disease and its incidence, classification, assessment and management.

RESULTS AND CONCLUSION

Perianal Crohn's disease can manifest as skin tags, ulcers, fissures, abscesses, fistulas or stenoses. Improved radiological imaging with endoanal anal ultrasonography and magnetic resonance imaging has improved its assessment and may be used to predict outcome after surgery. Many treatment options exist. During acute complications they are generally aimed at resolving the immediate problem and limiting damage to anal and perianal tissues; this may be a 'bridge' to definitive treatment. The likelihood of success of definitive treatment must be weighed against the risk of complications, especially faecal incontinence.

Treatment of inflammatory bowel disease with corticosteroids

Corticosteroids are a mainstay in the treatment of inflammatory bowel disease. Administered topically, orally, or intravenously corticosteroids rapidly and consistently improve moderate to severe active ulcerative colitis and Crohn's disease, although they are ineffective in the maintenance of remission in either illness. The beneficial effects of corticosteroid therapy are counterbalanced by their many side effects. A better understanding of the mechanism of steroid action and toxicity has led to the development of novel corticosteroids that offer the promise of continued efficacy with minimal toxicity. This article reviews the role of conventional and novel corticosteroids in the management of inflammatory bowel disease.

Review article: The medical treatment of Crohn's perianal fistulas

Perianal fistulas are a frequent manifestation of Crohn's disease. The correct application of the newer diagnostic and therapeutic agents for treating perianal Crohn's disease are beginning to be better defined. In general, a combined medical and surgical approach is preferred. The perianal disease process should first be fully delineated with endoscopy and either MRI or EUS before treatment is begun. Patients are then stratified into one of three groups: simple fistulas and no proctitis; simple fistulas and concomitant proctitis; and complex fistulas. Patients with simple fistulas and no proctitis can be treated medically with a combination of antibiotics and an immunosuppressive agent (azathioprine or mercaptopurine). Patients with simple fistulas and concomitant proctitis should have infliximab added to their treatment plan. Complex fistulas require surgical intervention first prior to medical treatment. A combination of antibiotics, immunosuppressive therapy and infliximab are then initiated to facilitate fistula healing.

Complications of pregnancy and child development after cessation of treatment with 6-mercaptopurine for inflammatory bowel disease

PURPOSE

6-Mercaptopurine (6-MP) has proven efficacy in the therapy of inflammatory bowel disease. Its teratogenicity is demonstrated in animal studies when used at very high doses, whereas human data suggest that 6-MP at maintenance doses is safe. We report the outcome of 72 pregnancies in patients with inflammatory bowel disease who were previously treated with 6-MP with three different doses of 50, 75, and 100 mg/d, for a median duration of 18 months, along with long-term follow-up of the children.

METHODS

We have compared the outcome of pregnancies and development of the offspring in the following two groups: group 1, patients with inflammatory bowel disease who conceived 6 months to 22 years after stopping 6-MP (median 72 months); and group 2, patients with inflammatory bowel disease who never received 6-MP prior to conception. All pregnancies were evaluated in terms of outcome: live full-term birth, premature delivery, stillbirth, spontaneous abortion, ectopic pregnancy, and therapeutic dilatation and curettage. Data on children were obtained regarding birth weight, congenital anomalies, and development.

RESULTS

Group 1 included 72 pregnancies carried by 29 women. There were 51 live births (4 premature), 16 spontaneous abortions, 1 stillbirth, 2 therapeutic abortions due to abnormal amniocentesis, and 2 ectopic pregnancies. The total incidence of fetal loss was 29.2%. In group 2, 75 women had 140 pregnancies resulting in 120 live births (8 premature), 18 spontaneous abortions, and 2 stillbirths. There were no cases of ectopic pregnancies or abnormal amniocentesis. The total incidence of fetal loss was 14.3%. There was no increase in the incidence of developmental defects when the mothers had been treated with 6-MP prior to pregnancy.

CONCLUSIONS

The incidence of fetal loss is higher in women with inflammatory bowel disease who had been previously treated with 6-MP compared with those who had not. Whether this was related to the older age at conception in 6-MP group, longer duration of disease, initially more severe disease, or use of 6-MP we cannot tell.

Transitioning the paediatric IBD patient to adult care

Transitioning an adolescent patient to an internist/gastroenterologist's care requires an understanding of the specific issues and challenges involved in the diagnosis and management of paediatric inflammatory bowel disease (IBD). Even though diagnostic criteria, as well as methods are the same in children and adults, younger patients may experience more insidious presentations. A high level of suspicion is necessary for an early and accurate diagnosis. Management of IBD in the paediatric population begins with the assessment of disease extent and activity as well as the identification of potentially serious complications (such as malnutrition, growth/sexual retardation and osteoporosis), which are often present at the time of diagnosis. Treatment includes not only medical, nutritional or surgical therapy but also a multidisciplinary or holistic approach taking into consideration the psychological as well as social impact of the disease on the patient and family.

Treatment of inflammatory bowel disease in childhood: best available evidence

The physician treating children with inflammatory bowel disease is confronted with a number of specific problems, one of them being the lack of randomized, controlled drug trials in children. In this review, the role of nutritional therapy is discussed with a focus on primary treatment, especially for children with Crohn's disease. Then, the available medical therapies are highlighted, reviewing the evidence of effectiveness and side effects in children, as compared with what is known in adults. Nutritional therapy has proven to be effective in inducing and maintaining remission in Crohn's disease while promoting linear growth. Conventional treatment consists of aminosalicylates and corticosteroids, whereas the early introduction of immunosuppressives (such as azathioprine or 6-mercaptopurine) is advocated as maintenance treatment. If these drugs are not tolerated or are ineffective, methotrexate may serve as an alternative in Crohn's disease. Cyclosporine is an effective rescue therapy in severe ulcerative colitis, but only will postpone surgery. A novel strategy to treat Crohn's disease is offered by infliximab, a monoclonal antibody to the proinflammatory cytokine tumor necrosis factor (TNF)-alpha. Based on the best-available evidence, suggested usage is provided for separate drugs with respect to dosage and monitoring of side effects in children.

Azathioprine in paediatric inflammatory bowel disease: an Italian multicentre survey

AIM

To assess the efficacy and safety of azathioprine in a paediatric population with inflammatory bowel disease.

PATIENTS AND METHODS

One hundred and twenty-three Italian children treated with azathioprine were studied retrospectively. The treatment duration and causes of its discontinuation, side-effects and variation in corticosteroid dose were assessed.

RESULTS

The mean age at inflammatory bowel disease diagnosis was 9.8 +/- 3.6 years, and at the start of azathioprine therapy 11.8 +/- 4.3 years. The mean duration of treatment was 19 +/- 16 months. Fifty patients (41%) stopped treatment due to surgery (12%), prolonged remission (11%), non-response (7%), severe side-effects (7%) and poor compliance (3%). Of the 73 patients (59%) remaining on azathioprine, 11 had never been treated with corticosteroids, 27 were able to stop them and 35 were still on a very low daily dose (91% < 0.3 mg/kg). The difference in the daily corticosteroid dose between the beginning of azathioprine treatment (1 +/- 0.6 mg/kg) and the conclusion of the study (0.18 +/- 0.16 mg/kg) was statistically significant. Side-effects were recorded in 48 of the 123 patients (39%), but only eight required discontinuation of azathioprine.

CONCLUSIONS

Azathioprine was efficacious in 70% of patients, but ineffective in 20% and induced severe toxicity in 7%. Corticosteroids were stopped or markedly reduced in 62% of patients, but they were never given in 9%.

Inflammatory Bowel Disease in Children

Crohn's disease and ulcerative colitis remain medically incurable conditions with potentially significant morbidity. The treatment of children with these conditions therefore should seek to reduce or eliminate symptoms, optimize nutritional status, promote normal growth and development, prevent complications, and minimize the potential psychologic effects of chronic illness. Treatment strategies must seek to both induce and maintain clinical remission. For all but the most mildly affected children with Crohn's disease, a combination of nutritional and pharmacologic approaches is optimal. For those with ulcerative colitis, anti-inflammatory medication is necessary. Moderate to severe Crohn's disease acutely responds best to potent immunomodulatory therapy, eg, corticosteroids and infliximab. Either agent must be coupled with 6-mercaptopurine or azathioprine to maintain long-term remission and to minimize toxicity. Particular attention must be paid to limit the growth suppression and other toxic effects of corticosteroids. Elemental or semielemental enteral nutrition also can induce remission effectively, but relapse is common after primary nutritional therapy is discontinued, mandating concomitant pharmacologic therapy with either 6-mercaptopurine or azathioprine. The availability of 6-mercaptopurine/azathioprine metabolite testing allows optimization of immunomodulatory therapy, detection of noncompliance, and avoidance of potentially dangerous toxicity. Mild ulcerative colitis acutely responds to treatment with a 5-aminosalicylate medication. Long-term remission frequently can be maintained with the same medication. Moderate to severe disease activity requires potent immunomodulatory therapy if colectomy is to be avoided. Surgery is a potential cure for patients with ulcerative colitis, although the development of pouchitis after ileal pouch anal anastomosis is common and frequently requires long-term medical management. Surgery provides only palliative relief of complications in those with Crohn's disease. Emerging therapies, especially evolving biologic and probiotic agents, offer hope for better treatments in the years ahead.

Immunomodulatory therapy for pediatric inflammatory bowel disease: changing patterns of use, 1990-2000

OBJECTIVE

To identify changes over the past decade in physicians' attitudes regarding the use of immunomodulatory agents for the treatment of children with inflammatory bowel disease (IBD), we surveyed the membership of the North American Society for Pediatric Gastroenterology and Nutrition and compared the responses to those from an identical survey performed in 1990.

METHODS

Surveys were mailed to 718 physicians in January, 2000. All surveys returned by mid-February were analyzed, and results compared to those obtained in the 1990 survey.

RESULTS

Thirty-nine percent (278/718) of surveys were returned, compared to 27% (105/385) in 1990. Overall, 93% of the current survey's respondents agreed with the statement "immunomodulatory agents are effective in the treatment of children and adolescents with IBD." Compared to 1990, significant increases (p < 0.0001) were noted in the percentage of respondents who prescribe immunomodulatory agents to children with all forms of IBD. Indications for immunomodulation that showed significant increases (p < 0.001) since 1990 included treatment of perianal and non-perianal fistulae; growth failure; use as initial, primary therapy; and use as prophylaxis against postoperative recurrence. 6-Mercaptopurine and azathioprine continue to be the agents prescribed by the greatest percentage of respondents. More physicians are willing to use immunomodulatory agents in children younger than 5 yr, and duration of use is longer than in 1990. Currently, physicians seem to favor the use of immunomodulatory agents over colectomy for children with either intractable ulcerative or Crohn's colitis. Most respondents remain concerned about potential bone marrow and immune suppression, but concerns regarding malignancy, teratogenicity, and infertility have lessened.

CONCLUSION

These survey findings document that pediatric gastroenterologists have widely accepted the use of immunomodulators in the treatment of children and adolescents with IBD.

6-MP metabolite profiles provide a biochemical explanation for 6-MP resistance in patients with inflammatory bowel disease

BACKGROUND & AIMS

Approximately 40% of inflammatory bowel disease (IBD) patients fail to benefit from 6-mercaptopurine (6-MP)/azathioprine (AZA). Recent reports suggest 6-thioguanine nucleotide (6-TGN) levels (>235) independently correlate with remission. An inverse correlation between 6-TGN and thiopurine methyltransferase (TPMT) has been described. The objectives of this study were to determine whether dose escalation optimizes both 6-TGN levels and efficacy in patients failing therapy because of subtherapeutic 6-TGN levels and its effect on TPMT.

METHODS

Therapeutic efficacy and adverse events were recorded at baseline and upon reevaluation after dose escalation in 51 IBD patients. 6-MP metabolite levels and TPMT activity were recorded blinded to clinical information.

RESULTS

Fourteen of 51 failing 6-MP/AZA at baseline achieved remission upon dose escalation, which coincided with significant rises in 6-TGN levels. Despite increased 6-MP/AZA doses, 37 continued to fail therapy at follow-up. Dose escalation resulted in minor changes in 6-TGN, yet a significant increase in 6-methylmercaptopurine ribonucleotides (6-MMPR) (P < or = 0.01) and 6-MMPR:6-TGN ratio (P < 0.001). 6-MMPR rises were associated with dose-dependent hepatotoxicity in 12 patients (24%). TPMT was not influenced by dose escalation.

CONCLUSIONS

Serial metabolite monitoring identifies a novel phenotype of IBD patients resistant to 6-MP/AZA therapy biochemically characterized by suboptimal 6-TGN and preferential 6-MMPR production upon dose escalation.

Pharmacokinetic considerations in the treatment of inflammatory bowel disease

This review describes the pharmacokinetics of the major drugs used for the treatment of inflammatory bowel disease. This information can be helpful for the selection of a particular agent and offers guidance for effective and well tolerated regimens. The corticosteroids have a short elimination half-life (t1/2beta) of 1.5 to 4 hours, but their biological half-lives are much longer (12 to 36 hours). Most are moderate or high clearance drugs that are hepatically eliminated, primarily by cytochrome P450 (CYP) 3A4-mediated metabolism. Prednisone and budesonide undergo presystemic elimination. Any disease state or comedication affecting CYP3A4 activity should be taken into account when prescribing corticosteroids. Depending on the preparation used, 10 to 50% of an oral or rectal dose of mesalazine is absorbed. Rapid acetylation in the intestinal wall and liver (t1/2beta 0.5 to 2 hours) and transport probably by P-glycoprotein affect mucosal concentrations of mesalazine, which apparently determine clinical response. Any clinical condition influencing the release and topical availability of mesalazine might modify its therapeutic potential. Metronidazole has high (approximately 90%) oral bioavailability, with hepatic elimination characterised by a t1/2beta of 6 to 10 hours and a total clearance of about 4 L/h/kg. Ciprofloxacin is largely excreted unchanged both renally (about 45% of dose) and extrarenally (25%), with a relatively short t1/2beta (3.5 to 7 hours). Thus, renal function affects the systemic availability of ciprofloxacin. Both mercaptopurine and its prodrug azathioprine are metabolised to active compounds (6-thioguanine nucleotides; 6-TGN) by hypoxanthine-guanine phosphoribosyltransferase and to inactive metabolites by the polymorphically expressed thiopurine S-methyltransferase (TPMT) and xanthine oxidase. Patients with low TPMT activity have a higher risk of developing haemopoietic toxicity. Both mercaptopurine and azathioprine have a short t1/2beta (1 to 2 hours), but the t1/2beta of 6-TGN ranges from 3 to 13 days. Therapeutic response seems to be related to 6-TGN concentration. Almost complete bioavailability has been observed after intramuscular and subcutaneous administration of methotrexate, which is predominantly (85%) excreted as unchanged drug with a t1/2beta of up to 50 hours. Thus, renal function is the major determinant for disposition of methotrexate. Cyclosporin is slowly and incompletely absorbed. It is extensively metabolised by CYP3A4/5 in the liver and intestine (median t1/2beta and clearance 7.9 hours and 0.46 L/h/kg, respectively), and inhibitors and inducers of CYP3A4 can modify response and toxicity. Infliximab is predominantly distributed to the vascular compartment and eliminated with a t1/2beta between 10 and 14 days. No accumulation was observed when it was administered at intervals of 4 or 8 weeks. Methotrexate may reduce the clearance of infliximab from serum.

Inflammatory bowel disease in the pediatric and adolescent patient

Advances in genetic testing have confirmed the presence of susceptibility loci on chromosomes 12 and 16 for UC and CD. These loci show a strong association with particular disease phenotypes that may explain the clinical heterogeneity of IBD. Whether multiple genotypes will be found to explain these phenotypes remains to be determined. Pharmacogenetic differences in 6-mercaptopurine metabolism can be used clinically to predict patient susceptibility to drug-induced toxicity. Novel treatment strategies are being developed at The Johns Hopkins Medical Center Hospital based on these inherent genetic differences. The aim is to improve treatment efficacy and clinical response times and prevent untoward drug-induced toxicity.

6-mercaptopurine metabolite levels in children with inflammatory bowel disease

OBJECTIVES

Some authors suggest that efficacy of 6-mercaptopurine (6-MP) in patients with inflammatory bowel disease correlates with circulating 6-thioguanine (6-TG) levels more than 235 pmol/8 x 10(8) red blood cells. The authors evaluated the relation between 6-MP metabolite levels and disease activity in children and adolescents with inflammatory bowel disease.

METHODS

Clinical status and hematologic and hepatic parameters were determined in 101 children with inflammatory bowel disease from a single center and compared with 6-MP metabolite levels.

RESULTS

There was a trend for higher 6-TG levels among patients in remission than among those with active disease (217 vs. 173); however the difference was not statistically significant ( P = 0.09). The likelihood of therapeutic response did not increase significantly at 6-TG levels greater than 235 pmol/8 x 10(8) red blood cells (odds ratio 1.7; P = 0.1). In the current study, 58% of patients in remission had 6-TG levels less than 235. However, serial measurements of 6-MP metabolite levels in 50 patients with active disease showed that increasing 6-TG levels correlated significantly with disease remission in patients followed up longitudinally ( P = 0.04). Leukopenia was significantly associated with high 6-TG levels ( P = 0.03) but not with clinical response ( P = 0.2).

CONCLUSIONS

These data suggest that the target range of 6-TG levels previously described by others did not apply to 58% of the pediatric patients with IBD in remission. However, serial monitoring of 6-MP metabolite levels in individual patients with active disease should allow dose escalation and induction of remission while minimizing the risk of toxicity.