Azathioprine and 6-mercaptopurine for the treatment of perianal Crohn's disease in children

Perianal fistulizing Crohn's disease: Current perspectives on diagnosis, monitoring and management with a focus on emerging therapies

Crohn's disease (CD), a chronic inflammatory bowel disorder, manifests in various phenotypes, with fistulizing perianal CD (CD-PAF) being one of its most severe phenotypes. Characterized by fistula formation and abscesses, CD-PAF impacts 17% to 34% of all CD cases and with a significantly deleterious impact on patient's quality of life, while increasing the risk for anorectal cancers. The pathogenesis involves a complex interplay of genetic, immunological and environmental factors, with cytokines such as tumor necrosis factor-alpha (TNF-α) and transforming growth factor-beta (TGF-β) playing pivotal roles. Diagnostic protocols require a multi-disciplinary approach including colonoscopy, examination under anesthesia and magnetic resonance imaging. In terms of treatment, biologics alone often prove inadequate, making surgical interventions such as setons and fistula surgeries essential. Emerging therapies such as mesenchymal stem cells are under study. The South Asian context adds layers of complexity, including diagnostic ambiguities related to high tuberculosis prevalence, healthcare access limitations and cultural stigma toward perianal Crohn's disease and ostomy surgery. Effective management necessitates an integrated, multi-disciplinary approach, especially in resource-constrained settings. Despite advances, there remain significant gaps in understanding the disease's pathophysiology and a dearth of standardized outcome measures, underscoring the urgent need for comprehensive research.

Management of Perianal Fistulizing Crohn's Disease

Perianal fistulizing Crohn's disease (CD) represents a severe phenotype of CD that is associated with significant morbidity and reduction in quality of life. Perianal fistulizing CD is caused by a complex interplay of genetic predisposition, immune dysregulation, gut dysbiosis, and various unknown physiological and mechanical factors. A multidisciplinary approach is hence required for optimal management . A detailed anatomical description and classification of perianal fistula, including comprehensive clinical, endoscopic, and radiological diagnostic workup, is an important prerequisite to treatment. For simple perianal fistulas, use of antibiotics and immunomodulators, with or without fistulotomy, are appropriate measures. The medical management of complex perianal fistula, on the other hand, requires adequate control of infection before initiation of therapy with immunomodulators. In active complex perianal fistula, anti-tumor necrosis factors remain the most accepted therapy, with concomitant use of antibiotics or immunomodulators enhancing the efficacy. For patients refractory to anti-tumor necrosis factors, treatment with anti-integrins, anti-interleukins, and small molecules is being evaluated. Mesenchymal stem cells, hyperbaric oxygen therapy, and exclusive enteral nutrition have also been investigated as adjunct therapies. Despite the expansion of the medical armamentarium, a large proportion of the patients require surgical interventions. In this review, we provide an up-to-date overview of the pathophysiology, clinical presentation, diagnosis, and medical management of perianal fistulizing CD. A brief overview of the surgical management of perianal fistulizing CD is also provided.

A Novel Patient-like Swine Model of Perianal Crohn's Disease

BACKGROUND

Perianal Crohn's disease is associated with poor outcomes and high medical costs. It is notoriously difficult to treat despite therapeutic advancements for luminal disease. A large animal model that mimics human perianal disease is needed to test innovative therapies.

OBJECTIVE

This study aimed to create a swine model that replicates the inflammatory component and therapeutic challenges found in patients with perianal Crohn's disease.

DESIGN

This was an animal preclinical study.

SETTINGS

The experiments were performed at the animal laboratory at the Johns Hopkins University.

PATIENTS

Four sus scrufus female pigs were included in the study.

INTERVENTIONS

Four female pigs underwent creation of 3 surgical perianal fistulas each, 1 rectovaginal and 2 perianal. Size 24 French setons were placed to maintain patency of the fistula tracts for 4 weeks. After removal of the setons, trinitrobenzene sulfonic acid was administered into the fistula tract to create and maintain local inflammation mimicking perianal Crohn's disease.

MAIN OUTCOMES MEASURES

An MRI was obtained to assess the fistulas and the pigs were euthanized to review histopathology.

RESULTS

Three inflammatory chronic fistula tracts were successfully created in each pig as confirmed by MRI and examination under anesthesia. This is the first report of maintaining patent fistulas in swine 2 weeks after removal of setons. For the first time, we reported that 2 pigs developed branching fistulas and small abscesses reminiscent of human perianal Crohn's disease. The corresponding histopathologic examination found significant chronic active inflammation on standard hematoxylin and eosin staining.

LIMITATIONS

The fistulas were surgically induced and did not occur naturally.

CONCLUSIONS

A chronic perianal fistula model in pigs that strongly resembles human perianal Crohn's disease was successfully created. This model can be used to test novel therapeutics and techniques to pave the path for human trials. See Video Abstract at http://links.lww.com/DCR/B969 .

UN NUEVO MODELO PORCINO SIMILAR A UN PACIENTE DE LA ENFERMEDAD DE CROHN PERIANAL ANTECEDENTES

La enfermedad de Crohn perianal se asocia con malos resultados y altos costos médicos. Es notoriamente difícil de tratar a pesar de los avances terapéuticos para la enfermedad luminal. Se precisa de un modelo animal grande que imite la enfermedad perianal humana para probar terapias innovadoras.OBJETIVO:Nuestro objetivo de este estudio fue crear un modelo porcino que replique el componente inflamatorio y los desafíos terapéuticos que se encuentran en los pacientes con enfermedad de Crohn perianal.DISEÑO:Este fue un estudio preclínico en animales.AJUSTES:Los experimentos se realizaron en el laboratorio de animales de la Universidad Johns Hopkins.PACIENTES:Se incluyeron en el estudio cuatro cerdas sus scrofa.INTERVENCIONES:Cuatro cerdas fueron sometidas a la creación de 3 fístulas perianales quirúrgicas cada una: 1 recto vaginal y 2 perianales. Se colocaron sedales de 24 French para mantener la permeabilidad de los trayectos fistulosos durante 4 semanas. Tras el retiro de los sedales, se administró ácido trinitrobenceno sulfónico en el trayecto de la fístula para crear y mantener la inflamación local simulando la enfermedad de Crohn perianal.PRINCIPALES MEDIDAS DE RESULTADOS:Se obtuvo una resonancia magnética para evaluar las fístulas y los cerdos fueron sacrificados para revisar la histopatología.RESULTADOS:Se crearon de manera exitosa tres trayectos fistulosos inflamatorios crónicos en cada cerdo, confirmados por imágenes de resonancia magnética y examen bajo anestesia. Este es el primer informe de preservación de fístulas permeables en cerdos 2 semanas tras el retiro de los setones. Por primera vez, informamos que dos cerdos desarrollaron fístulas ramificadas y pequeños abscesos que recuerdan a la enfermedad de Crohn perianal humana. El examen histopatológico correspondiente encontró una significativa inflamación crónica activa en la tinción estándar de hematoxilina y eosina.LIMITACIONES:Las fístulas se indujeron quirúrgicamente y no se produjeron de forma natural.CONCLUSIONES:Se logro recrear con éxito un modelo de fístula perianal crónica en cerdos que se asemeja mucho a la enfermedad de Crohn perianal humana. Este modelo se puede utilizar para probar nuevas terapias y técnicas para allanar el camino para los ensayos en humanos. Consulte Video Resumen en http://links.lww.com/DCR/B969 . (Traducción-Dr Osvaldo Gauto).

Medical and surgical management of pediatric perianal crohn's disease: A systematic review

BACKGROUND

The timely management of pediatric Crohn's disease (CD), and specifically perianal CD, is important owing to the possible adverse effects on growth, development, and quality of life. Perianal involvement is increasingly common, with up to 62% of pediatric CD patients affected. Presently, literature addressing the management of perianal CD has focused primarily on adults, with findings that cannot always be extrapolated to the pediatric population. We aimed to review the rates of healing, recurrence, and need for surgical intervention in perianal CD to provide evidence-based recommendations for the ideal management in children.

METHOD

We conducted a systematic review of CENTRAL, PubMed, Medline, and EMBASE databases (January 1997-December 2017) in accordance with PRISMA. Two independent reviewers performed data extraction.

RESULT

Ten studies met the inclusion criteria with a combined total of 538 patients. Median study population size was 17 (range 7-276), with a median age at intervention of 13.9 years (range 1-18). Seton placement allowed complete healing in 28.6% of children. Similar results (28.5%) were seen in children undergoing fecal diversion. One study demonstrated complete resolution of fistulizing disease in 70% of children treated with infliximab (IFX). One quarter of patients treated with IFX required further surgical intervention for disease control. Recurrence occurred most frequently in children undergoing Seton placement alone (5/14, 35.7%), compared with IFX (46/197, 23.4%) and combination therapy (12/276, 4.3%).

CONCLUSION

In the pediatric population, a combination of medical and surgical treatment is required to control perianal CD, with fewer side effects.

LEVEL OF EVIDENCE

Level II.

Identifying perianal fistula complications in pediatric patients with Crohn's disease using administrative claims

Background

Although perianal fistulas occur commonly in pediatric Crohn’s disease (CD), evaluations of health services have been limited since no validated claims-based methods exist for identifying cases.

Objective

To develop and validate accurate case definitions for perianal fistulas among pediatric patients with CD from administrative claims.

Methods

Retrospective cohort study in which we developed and tested candidate case definitions for perianal fistula. Patients (age 5–21 years between 2005–2012) with CD enrolled in Michigan Medicaid with healthcare at University of Michigan were identified via claims. Medical records were obtained from all identified patients, whose entire records were abstracted. Medical record evidence for perianal fistula was considered the “gold standard” against which candidate case definitions were compared. The reference case definition of perianal fistula (ICD9 565.1) and candidate case definitions were evaluated.

Results

Of 843 patients identified via claims, 274 (33%) met CD criteria for inclusion. The true perianal fistula rate among CD patients was 18% (n = 49). The top-performing candidate case definition identified 15% (n = 42), had sensitivity of 77.6%, specificity of 98.2%, positive predictive value (PPV) 90.5%, negative predictive value (NPV) 95.3%, and area under receiver operator characteristic curve (ROC) of 0.88. In contrast, the reference case definition identified 9% (n = 26), sensitivity 51.0%, specificity 99.6%, PPV 96.2%, NPV 90.3%, and had an area under ROC of 0.75.

Conclusions

We demonstrated that it is feasible to use administrative claims data to accurately identify pediatric patients with perianal fistula complications. Claims-based case definitions were found to be highly accurate through medical record review, providing a high degree of confidence for future studies where chart review is not feasible. These claims-based methods can be applied to claims data in other settings for the evaluation of health services utilization as well as to assess the comparative effectiveness of prevention and treatment strategies.

Increased expression of CXCR3 axis components and matrix metalloproteinase in pediatric inflammatory bowel disease patients

BACKGROUND

Although pediatric inflammatory bowel disease (IBD) is characterized by extensive intestinal involvement and rapid early progression, the precise cause and specific factors involved in disease aggravation have not been well established. The aim of this study was to investigate the pathogenesis of pediatric IBD.

METHODS

The expression of inflammatory molecules in colon samples taken from active ulcerative colitis (UC) and Crohn's disease (CD) patients was compared with those of controls. Three children each with UC and CD in both the active and remission phase and their controls were enrolled, and the inflammatory gene expression in the mucosa was examined by microarray. Additionally, six children from each group were further enrolled in a real-time reverse transcription polymerase chain reaction and an immunohistochemical study to examine the expression of CXCL9, 10, 11, CXCR3, matrix metalloproteinase (MMP)-1, -3, -7, and -10.

RESULTS

The microarray analysis revealed enhanced expression of the CXCL9, 10, and 11 genes in the active phase of CD. The expression of MMP-1, -3, -7, and -10 was significantly enhanced in the active phase of UC. These changes were also confirmed by real-time reverse transcription polymerase chain reaction. Immunohistochemical analysis revealed enhanced expression of CXCL9, 10, and 11 in both the lamina propria and epithelial cells in these patients. CXCR3-positive cells were also confirmed in the lamina propria. The expression of MMP-1, -3, -7, and -10 was also enhanced in the mucosal epithelial cells and the lamina propria in both CD and UC patients.

CONCLUSIONS

These findings suggest that CXCR3 axis components and MMP play an important role in the mucosal damage in pediatric IBD.

The safety and efficacy of adalimumab in patients with Crohn's disease: the experience of a single Canadian tertiary care centre

BACKGROUND. Adalimumab (ADA), an antitumor necrosis factor (anti-TNF) monoclonal antibody, is effective in treating moderate-to-severely active Crohn's disease (CD). ADA has been associated with a variety of adverse events (AE). The purpose of this study is to determine the safety and efficacy of ADA in CD patients in clinical practice. METHODS. A retrospective analysis was performed on CD patients treated with ADA. Data extracted and analyzed included patient and CD demographics, remission and response rates with ADA, and safety and tolerability of ADA. RESULTS. A total of 149 ADA-treated CD patients were included. The mean duration of therapy with ADA was 20 months with 32% of patients discontinuing treatment. Anti-TNF-naïve and anti-TNF-exposed patients on ADA achieved clinical remission in 45% and 32%, had a clinical response in 23% and 23%, and had no clinical response in 32% and 45%, respectively. Anti-TNF-naïve and anti-TNF-exposed patients maintained remission in 82% and 67%, respectively. Fistulas healed in 19% and improved in 19%. AE occurred in 38% of patients with infection being the most common (20%). Serious infections lead to death in one (<1%). Logistic regression of AE did not identify statistically significant predictors except for colonic disease location (odds ratio [OR] = 0.31, 95% CI = 0.12-0.82, p = 0.018) and the rate of ADA discontinuation (OR = 3.24, 95% CI = 1.58-6.64, p = 0.0013). CONCLUSION. ADA is an effective treatment for CD. AE can occur commonly leading to discontinuation of medication and may be influenced by disease location. Although serious complications are rare, close monitoring of all patients on ADA is needed.

Imaging techniques and combined medical and surgical treatment of perianal Crohn's disease

Crohn's disease is a chronic inflammatory disease which may involve any segment of the gastrointestinal tract, most frequently the terminal ileum, the large intestine, and the perianal region. The symptoms of perianal Crohn's disease include skin disorders, hemorrhoids, anal ulcers, anorectal stenosis, perianal abscesses and fistulas, rectovaginal fistulas and carcinoma of the perianal region. The perianal manifestations of Crohn's disease cause great discomfort to the patient and are among the most difficult aspects to treat. Management of perianal disease requires a combination of different imaging modalities and a close cooperation between gastroenterologists and dedicated surgeons.

Early administration of azathioprine vs conventional management of Crohn's Disease: a randomized controlled trial

BACKGROUND & AIMS

Immunomodulator therapy is effective for patients with Crohn's disease (CD) but has not been shown to affect disease progression, presumably because it is given too late after diagnosis. We compared the efficacy of early treatment (within 6 months after diagnosis) with azathioprine versus conventional management of patients at high risk for disabling disease.

METHODS

We performed an open-label trial of adults with a diagnosis of CD for less than 6 months who were at risk for disabling disease. From July 2005 to November 2010, patients at 24 French centers were randomly assigned to treatment with azathioprine (2.5 mg ∙ kg(-1) ∙ day(-1), n = 65) or conventional management (azathioprine only in cases of corticosteroid dependency, chronic active disease with frequent flares, poor response to corticosteroids, or development of severe perianal disease) (n = 67). The primary end point was the proportion of trimesters spent in corticosteroid-free and anti-tumor necrosis factor (TNF)-free remission during the first 3 years after inclusion.

RESULTS

During the 3-year follow-up period, 16 patients in the azathioprine group were switched to mercaptopurine or methotrexate therapy because of intolerance or poor efficacy. Forty-one patients in the conventional management group required immunosuppressant therapy (61%; median time to first prescription, 11 months). In the azathioprine group, a median 67% of trimesters were spent in remission (interquartile range, 11%-85%) compared with 56% in the conventional management group (interquartile range, 29%-73%) (P = .69). Among secondary outcomes, a higher cumulative proportion of patients in the azathioprine group were free of perianal surgery than in the conventional management group (96% ± 3% and 82% ± 6% at month 36, respectively; P = .036). The cumulative proportion of patients free of intestinal surgery and anti-TNF therapy did not differ between groups.

CONCLUSIONS

Based on results from a clinical trial, administration of azathioprine within 6 months of diagnosis of CD was no more effective than conventional management in increasing time of clinical remission. Clinicaltrials.gov, Number NCT00546546.

Diagnosis and treatment of perianal Crohn disease: NASPGHAN clinical report and consensus statement

Inflammatory bowel disease is a chronic inflammatory disorder of the gastrointestinal tract that includes both Crohn disease (CD) and ulcerative colitis. Abdominal pain, rectal bleeding, diarrhea, and weight loss characterize both CD and ulcerative colitis. The incidence of IBD in the United States is 70 to 150 cases per 100,000 individuals and, as with other autoimmune diseases, is on the rise. CD can affect any part of the gastrointestinal tract from the mouth to the anus and frequently will include perianal disease. The first description connecting regional enteritis with perianal disease was by Bissell et al in 1934, and since that time perianal disease has become a recognized entity and an important consideration in the diagnosis and treatment of CD. Perianal Crohn disease (PCD) is defined as inflammation at or near the anus, including tags, fissures, fistulae, abscesses, or stenosis. The symptoms of PCD include pain, itching, bleeding, purulent discharge, and incontinence of stool. In this report, we review and discuss the etiology, diagnosis, evaluation, and treatment of PCD.

Managing Perianal Crohn’s Disease

Perianal Crohn’s Disease (CD) is a significant cause of morbidity in CD patients. Accurate identification of perianal involvement requires advanced imaging techniques in addition to physical exam. Treatment of the disease is aimed at improving both the perianal and intestinal manifestations. Proper treatment depends upon the severity of the disease and combines current medical and surgical therapies to maximize response. The ability to improve perianal disease has grown significantly since the introduction of anti-TNF agents which are now a mainstay of treatment along with antibiotics and immunomodulators. New experimental therapies are limited by lack of research to support their use.

Review article: medical, surgical and radiological management of perianal Crohn's fistulas

BACKGROUND

Crohn's anal fistulas are common and cause considerable morbidity. Their management is often difficult; medical and surgical treatments rarely lead to true healing with frequent recurrence and complications.

AIM

To examine medical treatments previously and currently used, surgical techniques and the important role of optimal imaging.

METHODS

We conducted a literature search in the Pub Med database using Crohn's, Anal Fistula, Surgery, Imaging and Medical Treatment as search terms.

RESULTS

Antibiotics and immunosuppressants have a role, but slow initial response, side effects and relatively low remission rates of up to around a third with frequent recurrence limit their value. Long-term infliximab produces clinical remission in 36-58% of patients with combined medical and surgical management achieving optimal outcomes. Traditional and newer surgical procedures often have a high rate of recurrence with a significant risk of temporary or, in up to 10% of cases, permanent stomas, incontinence and unhealed or slowly healing wounds in 30%.

CONCLUSIONS

Management of Crohn's anal fistulas remains challenging. Established principles are to drain infection, use setons as required, aggressively manage active proctitis, give antibiotics, immunosuppressants and employ anti-TNFα therapy, and they demand significant co-operation between gastroenterologists and surgeons.

Monitoring 6-thioguanine nucleotide concentrations in Japanese children and adolescents with inflammatory bowel disease

BACKGROUND AND AIM

6-Mercaptopurine (6-MP) and azathioprine (AZA) are widely used as maintenance therapy in children with inflammatory bowel disease (IBD). However, proper 6-thioguanine nucleotide (6-TGN) concentrations in Japanese children with IBD have not been reported.

METHODS

This retrospective review examines 32 ulcerative colitis (UC) patients and 19 Crohn's disease (CD) patients (12.87 ± 3.56 years) who required 6-MP or AZA to maintain disease remission. All patients were treated with 6-MP or AZA for at least 3 weeks prior to this study in addition to previous treatment. 6-MP dose, 6-TGN levels, assayed by high-performance liquid chromatography, as well as laboratory data were evaluated.

RESULTS

Thirty-five children were successfully kept in remission with 6-MP and AZA therapy after weaning off corticosteroids. Overall, 123 measurements (59 active disease, 64 in remission) were analyzed. The mean 6-TGN concentration of the entire study population was 499.61 ± 249.35 pmol/8 × 10(8) red blood cell. The mean 6-MP dose in patients with active disease (0.910 ± 0.326 mg/kg per day) was significantly higher than for patients in remission (0.749 ± 0.225) (P = 0.0016). A significant inverse correlation was found between white blood cell counts and 6-TGN concentrations (r = 0.275, P < 0.002). Two patients experienced leukopenia with alopecia, and four transiently experienced increased serum levels of pancreatic enzymes, although no thiopurine S-methyl transferase mutations were confirmed.

CONCLUSION

The doses of 6-MP or AZA needed to maintain remission in Japanese children with IBD are lower than those reported in Western countries. However, 6-TGN concentrations in this population are higher than previously reported.

Thiopurine therapy in inflammatory bowel disease

The thiopurines azathioprine and 6-mercaptopurine have been used in the treatment of Crohn's disease and ulcerative colitis for over 40 years. Randomized controlled trials have supported their use in the treatment of active disease, as well as for the maintenance of disease remission. Presently, the most debated issues surrounding the thiopurines include: the role of thiopurine methyltransferase and metabolite-adjusted dosing in enhancing efficacy and minimizing toxicity; the timing of thiopurine use, that is, earlier versus later use during the course of the disease; the selection of thiopurine monotherapy versus combination therapy with an anti-TNF-α; agent; and the safety profile of thiopurines. Accumulated evidence has supported the safety of 6-mercaptopurine/azathioprine use in pregnancy and lactation. Thiopurine therapy in inflammatory bowel diseases is associated with an increased risk of lymphoproliferative disorders. Factoring their proven efficacy over a broad range of clinical scenarios within Crohn's disease and ulcerative colitis together with their overall safety profile and convenient and inexpensive once-daily oral administration, azathioprine and 6-mercaptopurine remain among the mainstays of Crohn's disease and ulcerative colitis therapy.

Randomized clinical trial of metronidazole ointment versus placebo in perianal Crohn's disease

BACKGROUND

The potential for metronidazole 10 per cent ointment to exert therapeutic benefit in perianal Crohn's disease, while minimizing the adverse effects found with oral metronidazole, was evaluated in a randomized placebo-controlled study.

METHODS

Subjects with perianal Crohn's disease were randomized to metronidazole 10 per cent ointment, 0.7 g applied perianally three times daily, or placebo ointment. The Perianal Crohn's Disease Activity Index (PCDAI) was scored at baseline and after 4 weeks of treatment. Perianal pain was assessed on a visual analogue scale.

RESULTS

Seventy-four subjects (33 metronidazole, 41 placebo) were evaluated. The mean(s.e.m.) reduction in PCDAI score at 4 weeks was 2.4(0.5) in the metronidazole group and 2.2(0.4) in the placebo group (P = 0.660). More subjects in the metronidazole group than the placebo group showed a reduction in PCDAI score of at least 5 points (10 of 27 versus 4 of 34; P = 0.031). Perianal discharge was reduced significantly in metronidazole-treated subjects (P = 0.012). A greater reduction in perianal pain was seen in the metronidazole group, which approached statistical significance (P = 0.059). No serious adverse events were reported.

CONCLUSION

Metronidazole 10 per cent ointment was not effective in the reduction of PDCAI score, but some secondary outcomes showed improvement suggestive of a treatment effect. It is well tolerated, with minimal adverse effects, and has potential as treatment for pain and discharge associated with perianal Crohn's disease.

REGISTRATION NUMBER

NCT00509639 (http://www.clinicaltrials.gov).

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.

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.

Course and treatment of perianal disease in children newly diagnosed with Crohn's disease

BACKGROUND

We sought to characterize perianal disease and its treatment in pediatric patients newly diagnosed with Crohn's disease.

METHODS

Data were obtained from the Pediatric Inflammatory Bowel Disease (IBD) Collaborative Group Registry, a prospective, multicenter observational registry recording clinical and laboratory outcomes in children under 16 years of age newly diagnosed with IBD. Patients with Crohn's disease were selected who had data on perianal disease and at least 24 months of follow-up. The records of patients with a Pediatric Crohn's Disease Activity Index perianal subscore greater than 0 were reviewed, and patients with abscesses or fistulas were selected. The therapies used and the course of their perianal disease were then assessed.

RESULTS

Of the 276 patients identified, 41 had perianal lesions within 30 days of diagnosis. Thirteen of these had skin tags and fissures only, whereas 28 had fistulas and/or abscesses. The latter lesions resolved by 1 year in 20 patients, and 8 had chronic/recurrent perianal disease persisting for more than 1 year following diagnosis. Patients with fistulizing disease were much more likely to be treated and were treated earlier with antibiotics, infliximab, and immunomodulators than were nonfistulizing patients. Patients who developed chronic perianal disease were more likely to have low body mass indices and required more perianal surgery than did patients whose perianal disease resolved.

CONCLUSIONS

Approximately 10% of newly diagnosed pediatric patients with Crohn's disease will have perianal fistulas and/or abscesses at the time of diagnosis. Most of these will resolve within a year with medical therapy alone.

Long-Term Evaluation of Canine Perianal Fistula Disease Treated With Exclusive Fish and Potato Diet and Surgical Excision

The records of 33 dogs that had perianal fistula disease treated with en bloc surgical excision and bilateral anal saculectomy, and that were perioperatively administered an exclusive white fish and potato diet, were reviewed to determine outcome. By 1 year after surgery, 87.9% of the dogs had complete or near-complete resolution of visible fistula disease, while only 20.7% continued to have mild intermittent clinical signs. Fecal incontinence was not reported in any dog. Overall, complications were considerably less in both severity and frequency when compared with previous reports.

Managing Crohn disease in children and adolescents : focus on tumor necrosis factor antagonists

Crohn disease (CD) is a chronic inflammatory disorder of the gastrointestinal tract characterized by a relapsing course and variable presentation that often includes abdominal pain, diarrhea, and fatigue. CD frequently presents during childhood, resulting in pediatric-specific complications, such as growth failure and delayed puberty. Conventional drug therapy for moderate to severe pediatric CD includes induction of remission with corticosteroids, and maintenance of remission with immunomodulators. Patients who have an inadequate response to standard therapy are being increasingly treated with anti-tumor necrosis factor-alpha (TNFalpha) agents. Infliximab has been the most widely studied anti-TNFalpha agent in pediatric CD, and has been shown to be efficacious in this condition. Adalimumab has been proven to be efficacious in adults with CD, but there has been only a single case report in children. CDP571 has been tested in 20 children with CD, showing some efficacy. Finally, thalidomide therapy has been associated with improvement in two small case series. Toxicities of these agents include infusion reactions, infections, malignancies, neurologic disorders, and hematologic derangements.

Specific considerations in the treatment of pediatric inflammatory bowel disease

Inflammatory bowel disease is one of the most prevalent chronic inflammatory disorders and commonly presents during childhood or adolescence. Occurring during a critical period of growth and development, pediatric Crohn's disease and ulcerative colitis require special consideration. Children often experience growth failure, malnutrition, pubertal delay and bone demineralization. Medical treatment must be optimized to promote clinical improvement and reverse growth failure with minimal toxicity. In addition to pharmacologic and surgical interventions, nutritional therapies play a vital role in the management of pediatric inflammatory bowel disease. This review will outline the epidemiology and clinical complications that are unique to pediatric inflammatory bowel disease, current trends, and recent advances in nutritional and pharmacologic treatment, and projected future therapeutic direction.

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.

The patient with persistent perianal fistulae

The management of patients with persistent perianal fistulae depends on thorough evaluation by clinical history and examination, assessment of intestinal disease and assessment of perianal disease. The main therapeutic options are medical and surgical treatment and their appropriate integration is essential for the optimal management of the patients. Medical treatment includes antibiotics, azathioprine or 6-mercaptopurine, infliximab and tacrolimus or cyclosporine. Surgical treatment includes fistulotomy, placement of setons, endorectal advancement flaps, fecal diversion and proctectomy. Fistula recurrence often occurs, possibly due to early discontinuation of medication or premature removal of setons. Using anorectal endoscopic ultrasound or magnetic resonance imaging to guide therapy, the healing rates of perianal fistula can be increased. In persistent complex perianal fistulae where medical treatment initially fails, examination under anaesthesia and placement of non-cutting setons, when necessary, combined with medical treatment results in higher healing rates.

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.

Review article: Medical therapy for fistulizing Crohn's disease

BACKGROUND

Fistulae will develop in approximately one-third of patients with Crohn's disease. With an expected spontaneous healing rate of only 10%, fistulizing Crohn's disease requires a comprehensive strategy with a medical and possible surgical approach.

AIM

To summarize the current literature evaluating various medical options for treating patients with fistulizing Crohn's disease.

METHODS

A literature review was conducted using PubMed (search terms: Crohn's disease and fistula) and manual search of references among the identified studies and relevant review papers to identify papers that present data on medical treatment of fistulizing Crohn's disease.

RESULTS

The first line of medical therapy remains antibiotics (metronidazole and ciprofloxacin). Mercaptopurine and azathioprine are medications that are effective in treating fistulizing Crohn's disease. The current gold standard of medical treatment to induce and maintain remission for fistulizing Crohn's disease is infliximab. Used as induction therapy, infliximab produced a 62% clinical response, and a complete closure rate of 46%. A maintenance therapy trial demonstrated at 54 weeks, 46% of patients receiving infliximab continued to respond to treatment, compared with 23% in the placebo group (P = 0.001).

CONCLUSION

Further research to find new therapies and to improve our existing medical treatment of fistulizing Crohn's disease is required.

Azathioprine maintains first remission in newly diagnosed pediatric Crohn's disease

6-Mercaptopurine (6-MP) maintains remission in pediatric Crohn's disease (CD). Azathioprine, a prodrug of 6-MP, is used for maintenance of remission of CD in Europe. We evaluated to what extent azathioprine is used in newly diagnosed pediatric CD patients and whether maintenance of remission differed between patients using azathioprine or not. Charts of children (diagnosed 1998-2003, follow-up > or = 18 mo) were reviewed. Active disease was defined as Pediatric Crohn's Disease Activity Index (PCDAI) greater than 10 or systemic corticosteroid use. Remission was defined as PCDAI 10 or less without use of corticosteroids. Eighty-eight children (55M/33F, age 12 +/- 3 yr) were included. Seventy-two (82%) patients received azathioprine during the follow-up period (38 +/- 17 mo). Patients diagnosed after 2000 received azathioprine significantly earlier during the course of disease compared with those diagnosed earlier (median, at 233 vs. 686 days; P < 0.05). At initial presentation, moderate-severe disease activity and prescription of corticosteroids were more prevalent in patients using azathioprine compared with nonazathioprine patients (75% vs. 52%; P < 0.05; and 89% vs. 58%; P < 0.005, respectively). Duration of corticosteroid use was longer in patients receiving azathioprine (232 vs. 168 days; P < 0.005). Median maintenance of first remission in patients who initially used corticosteroids, however, was longer in patients receiving azathioprine compared with nonazathioprine patients (PCDAI, 544 vs. 254 days, P = 0.08; corticosteroid free, 575 vs. 259 days, P < 0.05, respectively). We conclude that, since 2000, azathioprine is being introduced earlier in the treatment of newly diagnosed pediatric CD patients. The use of azathioprine is associated with prolonged maintenance of the first remission.

Management of Perianal Crohn's Disease

Perianal manifestations of Crohn's disease usually coexist with active inflammation of other primary sites of the disease. Although treatment of active proximal disease may sometimes alleviate perianal symptoms, it is reasonable to separately treat symptomatic perianal disease. The diversity of perianal manifestations in Crohn's disease mandates a tailored, individualized approach in every case. Medical therapy is the best treatment option for hemorrhoids and anal fissures. The medical management of patients with perianal Crohn's disease includes the use of systemic antibiotics, immunosuppressive agents, and infliximab. Infliximab is now recognized as a very efficacious agent for treating fistulizing Crohn's disease, including perianal fistulae. It may also reduce the need for surgical intervention in specific cases. Abscesses and fistulae are treated by control of sepsis, resolution of inflammation and optimal preservation of continence, and quality of life. Abscesses require surgical drainage that may need to be prolonged to achieve complete healing. Fistulae may be treated medically, especially in cases of concurrent proctitis. Refractory fistulae may require surgical treatment including an occasional need for fecal diversion or proctectomy. The role of new treatment options such as natalizumab and CDP571 is evolving and requires further investigation.

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.

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.

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.

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.

A Perspective on inflammatory bowel disease in the child and adolescent at the turn of the millennium

The literature of the past year has produced significant advances relevant to the diagnosis and treatment of children and adolescents with inflammatory bowel disease. This review focuses on new observations regarding the epidemiology, genetics, etiology, diagnosis, and treatment of both Crohn's disease and ulcerative colitis in children. Particular attention is paid to the expanded indications for the use of immunomodulatory therapy, and to the early published data regarding the safety and efficacy of treatment with infliximab.