Azathioprine for maintaining remission of Crohn's disease

Personalized Treatment for Crohn's Disease: Current Approaches and Future Directions

Crohn's disease is a complex, relapsing and remitting inflammatory disorder of the gastrointestinal tract with a variable disease course. While the treatment options for Crohn's disease have dramatically increased over the past two decades, predicting individual patient response to treatment remains a challenge. As a result, patients often cycle through multiple different therapies before finding an effective treatment which can lead to disease complications, increased costs, and decreased quality of life. Recently, there has been increased emphasis on personalized medicine in Crohn's disease to identify individual patients who require early advanced therapy to prevent complications of their disease. In this review, we summarize our current approach to management of Crohn's disease by identifying risk factors for severe or disabling disease and tailoring individual treatments to patient-specific goals. Lastly, we outline our knowledge gaps in implementing personalized Crohn's disease treatment and describe the future directions in precision medicine.

Azathioprine monotherapy withdrawal in inflammatory bowel diseases: A retrospective mono-centric study

BACKGROUND

There is no consensus on the recommended duration of and optimal time to stop azathioprine (AZA) therapy in inflammatory bowel disease (IBD). Determining the optimal duration and cessation time can help to balance the risks of long-term intake with the possibility of relapse after cessation.

AIM

To describe the events following AZA cessation.

METHODS

Retrospective analysis was performed to examine data from adult patients affected by IBD who were followed at the University of Padua and had started but then discontinued AZA between 1995 and 2022. Data on therapy duration, reasons for cessation, and type of relapse after cessation were collected. Cox regression models were used to estimate the risk of relapse in different subgroups.

RESULTS

A total of 133 ulcerative colitis patients and 141 Crohn’s disease patients were included. Therapy with AZA was stopped in the 1^st year in approximately 34% of patients but was continued for more than 10 years in approximately 10% of cases. AZA discontinuation was due to primary failure or disease relapse in 30% of patients and due to disease remission in 25.2% of patients. Most of the remaining cases stopped AZA therapy due to side effects (primarily clinical intolerance, cytopenia, and pancreatic disease). Patients who stopped AZA for clinical remission had an 83% lower risk of relapse during the observation time than other groups, with a relapse-free rate of 89% after 1 year and 79% after 2 years.

CONCLUSION

AZA administration is effective and safe, but it requires careful monitoring for potential minor and major side effects. Only 10% of patients who achieved remission with AZA needed a new treatment within 1 year of drug interruption.

Systematic review: The effectiveness of 6-thioguanine nucleotide-based dose optimisation of thiopurines in the treatment of inflammatory bowel disease

Introduction: Clinical guidelines highlight the potential utility of metabolite-based thiopurine dose optimisation strategies in inflammatory bowel disease (IBD). The aim of this review was to summarise the evidence of effectiveness and safety of a 6-thioguanine nucleotide (6-TGN) metabolite-based dosing strategy for maintenance of remission using azathioprine or mercaptopurine in Crohn's disease and ulcerative colitis. Methods: We searched the Cochrane central register of controlled trials, EMBASE, clinicaltrials.gov, the WHO international clinical trials registry platform, and relevant grey literature, up to 1 December 2021. Inclusion criteria were: all randomised (active comparator) controlled trials of azathioprine or mercaptopurine used for the purposes of maintenance of remission in Crohn's disease or ulcerative colitis where the dose in the intervention arm was optimised based on 6-TGN metabolite assay results. Studies of any duration were eligible for inclusion, and no age restrictions were applied. Results: No studies met the eligibility criteria for this review. Four randomised controlled studies (two of which are currently underway) were identified that assessed the effectiveness of metabolite-based dose optimisation for thiopurine therapy, but were not eligible either because they did not differentiate between induction and maintenance therapy or because of a lack of an appropriate active comparator. Conclusions: There is no RCT-based evidence for dose optimisation using a 6-TGN metabolite-based dosing strategy for maintenance of remission in Crohn's disease or ulcerative colitis. Where evidence is available from combination induction and maintenance trials, it suggests that such a strategy is no better than weight-based dosing. Cochrane protocol registration: CD014795

A Method Using Longitudinal Laboratory Data to Predict Future Intestinal Complication in Patients with Crohn's Disease

BACKGROUND

Stenosis, fistulization, and perforation of the bowel are severe outcomes which can occur in patients with Crohn's disease. Accurate prediction of these events may enable clinicians to alter treatment strategies and avoid these outcomes.

AIMS

To study the correlation between longitudinal laboratory testing and subsequent intestinal complications in patients with Crohn's disease.

METHODS

An observational cohort of patients with Crohn's disease at a single center were analyzed between 01/01/1994 and 06/30/2016. A complication was defined as the development of an intestinal fistula, stenosis, or perforation. Exploratory analysis using Cox regression was performed to select the best statistical method to represent longitudinal laboratory data. Cox regression was used to identify laboratory variables independently associated with the development of a subsequent complication. A clinical scoring tool was designed.

RESULTS

In 246 patients observed over a median of 5.72 years, 134 complications occurred. Minimum or maximum value in a preceding window period of one year was most strongly associated with subsequent complication. A Longitudinal Laboratory score of ≥ 2 (maximum albumin level < 39 g/L = 1, maximum mean cell volume < 88 fL = 1, minimum platelet count > 355 × 10⁹/L = 1, minimum C reactive protein > 5 mg/L = 1) was 62% sensitive and 91% specific in identifying patients who develop a subsequent complication.

CONCLUSION

A consistent reduction in serum albumin and mean cell volume, and a consistent increase in platelet count and C reactive protein were associated with a subsequent complication in patients with Crohn's disease. Longitudinal laboratory tests may be used as described in this paper to provide a rational for earlier escalation of therapy.

Monotherapy with thiopurines in stricturing Crohn's disease: A real-life experience from low- and middle-income countries

BACKGROUND

Stricturing Crohn's disease (CD) is difficult to manage medically with limited treatment options, anti-tumor necrosis factor (TNF) therapy being the first-line therapy. Although thiopurines are also recommended first-line treatment option for maintenance of remission in steroid-dependent CD, evidence on their use in stricturing CD is lacking. We evaluated the efficacy of azathioprine (AZA) in patients with stricturing CD.

METHODS

In this retrospective cohort study (January 2005 to July 2020), patients with stricturing CD who were managed with AZA as a primary therapy for at least 6 months, and had a follow-up of at least 6 months after AZA initiation were included. Disease characteristics, complications, long-term response, and adverse events were noted.

RESULTS

One hundred and fifteen patients were included (mean age 33.8±14 years, 67.8% males, median disease duration 98 months [IQR: 60-158], median follow-up duration 60 months [IQR: 50-96]). 46.1% (n=53) patients had significant anemia at presentation, and 73% (n=84) had isolated small bowel involvement. Median dose of AZA was 100 mg (equivalent to 1.5 mg/kg). Median therapy and follow-up duration (after AZA initiation) was 17 (IQR: 9-42) and 33 months (IQR 18-60), respectively. The cumulative probability of maintaining response without treatment failure at 1, 2, and 5 years was 73.1%, 40.7%, and 18.5%, respectively. Among patients with AZA failure, 15.6% received methotrexate, 13% received anti-TNFs, and 9.5% underwent surgery. Significant anemia (&lt;10 g/dL) at presentation and steroid dependence predicted AZA failure. 31.3% patients experienced adverse events, commonest being leukopenia (n=29, 25.2%).

CONCLUSION

Azathioprine demonstrated good short-term and modest long-term response rates in patients with stricturing CD.

Epstein-Barr Virus Status and Subsequent Thiopurine Exposure Within a Paediatric Inflammatory Bowel Disease Population

The use of thiopurine therapy in Epstein-Barr virus (EBV)-naïve inflammatory bowel disease (IBD) patients remains controversial due to a risk of EBV-associated complications. We evaluated EBV status and outcomes within our paediatric IBD population over an 8-year period; finding that 217 of 409 (53%) screened patients were seropositive for EBV at IBD diagnosis; that thiopurines were used in 189 of 217 (87%) seropositive and 159 of 192 (83%) seronegative patients (P = 0.22); and that 7 of 192 (4%) previously seronegative patients subsequently tested positive for EBV with 6 of 7 (86%) patients having concurrently recorded thiopurine use. All six patients continued thiopurine with/without a period of cessation; no EBV-associated lymphoproliferative disorders/serious complications were recorded within our cohort. A significant proportion of our patients would not receive thiopurine therapy should their use be avoided in EBV-negative patients (47%) or seronegative males (30%). The small but significant risks of thiopurine treatment must be balanced against the potential benefits of successful IBD management; further research into this is required.

Poor Drug Sustainability in Inflammatory Bowel Disease Patients in Clinical Remission on Thiopurine Monotherapy

BACKGROUND

Immunomodulator monotherapy is an important component in the treatment of inflammatory bowel disease (IBD). However, there is conflicting literature about thiopurines maintaining long-term remission in patients with active IBD.

AIM

To determine the durable clinical remission rate in adults with Crohn's disease (CD) or ulcerative colitis (UC) on thiopurine monotherapy over 5 years.

METHODS

We performed a retrospective analysis of adult patients identified at McGill University Health Centre from 2009 to 2012. We included IBD patients who initiated thiopurine monotherapy and were in remission for at least 3 months (Harvey-Bradshaw Index (HBI) < 5 points for CD and partial Mayo Score (pMS) < 2 points in UC). The primary endpoint was sustained clinical remission on thiopurines during a 5-year follow-up. This included patients who had not relapsed or discontinued the drug due to side effects. The secondary endpoint was clinical relapse over the follow-up period, which was defined as HBI > 5 in CD and pMS > 2 in UC.

RESULTS

There were 148 patients included in the study (100 CD; 48 UC). At 5 years, 23% (34/148) patients remained in clinical remission on thiopurine monotherapy (25 CD and 9 UC patients). Thirty-three percent (33/100) of CD and 46% (22/48) of UC patients relapsed while on thiopurines. There was no difference in relapse rates between CD and UC patients. Eighty-four percent (42/50) of patients with CD with side effects and all UC (17/17) patients who experienced side effects discontinued the drug.

CONCLUSION

This analysis demonstrates that there is poor sustainability of clinical remission in IBD patients on thiopurine monotherapy given that a high proportion of patients discontinue thiopurines due to either relapse or side effects.

Optimizing the Use of Current Treatments and Emerging Therapeutic Approaches to Achieve Therapeutic Success in Patients with Inflammatory Bowel Disease

The current goal of inflammatory bowel disease (IBD) treatment is a symptom-free everyday life accompanied by mucosal healing with minimal use of corticosteroids. Recent therapeutic advances, particularly, the emergence of anti-tumor necrosis factor (anti-TNF) antibodies, have changed the natural history of IBD. Additionally, these advances also led to the emergence of the therapeutic concept of the “treat to target” strategy. With the development of new drugs and clinical trials, not only biologics but also small molecules have been applied to clinical practice to better individualize and optimize therapy. However, if newer drugs, including anti-TNF therapies, are recommended for all patients diagnosed with IBD, a significant number of patients will be overtreated. The basic goal of IBD treatment is still to make the best use of conventional treatments based on IBD pathophysiology. Thus, physicians should be familiar with the modes of action of the available drugs. In this review, the author discusses the existing data for many approved drugs and provide insights for optimizing current treatments for the management of patients with IBD in the era of biologics.

Steroid use and misuse: a key performance indicator in the management of IBD

Corticosteroids remain an important tool for inducing remission in inflammatory bowel disease (IBD) but they have no role in maintenance of remission. The significant adverse side effect profile of these drugs means their use should be avoided where possible or measures taken to reduce their risk. Despite an expanding array of alternative therapies, corticosteroid dependency and excess remain common. Appropriate steroid use is now regarded a key performance indicator in the management of IBD. This article aims to outline indications for corticosteroid use in IBD, their risks and strategies to reduce their use and misuse.

Benchmark study of benzamide derivatives and four novel theoretically designed (L1, L2, L3, and L4) ligands and evaluation of their biological properties by DFT approaches

Four novel ligands, namely N-benzhydryl benzamide, N, N-diphenethyl benzamide, N, N-dihexyl benzamide, and N, N-dioctyl benzamide (L1, L2, L3, and L4, respectively), based on the benzamide unit were designed and computed for their different properties, such as absorption spectrum, dipole moment, theoretically expected biological properties, and frontier molecular orbitals, by evaluating the HOMO/LUMO energy orbitals strength with DFT approaches and comparing these properties with the R benzamide properties available in literature. All molecules have a suitable frontier molecular orbital diagram and L1 exhibits maximum absorption at 246.8 nm due to the strong electron donating effect of the diphenylmethane ligand group. Moreover, strongly extended conjugated groups caused a redshift in absorption spectra. Newly designed molecules may show strong biological activities against cancer, bacterial diseases, and harmful fungal disorders. Graphical abstract Orbital energy, electron density and frontier molecular orbitals view of four designed novel benzamide derivates.

Cytomegalovirus reactivation in inflammatory bowel disease: an uncommon occurrence related to corticosteroid dependence

Cytomegalovirus promotes mucosal injury in patients with inflammatory bowel disease, historically affecting 10-25% of ulcerative colitis patients with refractory disease. Viral reactivation is likely related to long-term corticosteroid therapy, which is no longer central to maintenance of patients with inflammatory bowel disease. We hypothesize that viral detection rates have decreased in the modern era, reflecting widespread use of immunomodulatory agents to control inflammation. We performed this study to evaluate the relationships between medical regimens and cytomegalovirus detection rates among patients with inflammatory bowel disease. We searched our database for all patients with established inflammatory bowel disease and severe flares diagnosed from 2002 to 2017. Patients maintained with corticosteroid therapy were considered to be corticosteroid-dependent and those treated with other agents were classified as corticosteroid-independent, provided they had not received corticosteroids within 6 months of colonoscopy. Biopsy samples were reviewed for viral inclusions and subjected to cytomegalovirus immunohistochemistry, and rates of viral detection were compared between groups. There were 135 corticosteroid-dependent patients; most had ulcerative colitis flares occurring during the 2002-2009 period. Patients with ulcerative colitis and Crohn disease were equally represented in the corticosteroid-independent group (n = 133) and most were evaluated for disease flares during the 2010-2017 interval. Cytomegalovirus was detected in 13 (8%) cases; 9 (69%) were diagnosed from 2002 to 2009 and all were obtained from corticosteroid-dependent patients (p = < 0.001). We conclude that rates of cytomegalovirus-related enterocolitis are declining among inflammatory bowel disease patients, reflecting a shift away from corticosteroid-based maintenance therapy in favor of more effective agents that do not promote viral reactivation.

Evidence-based clinical practice guidelines for inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic disorder involving mainly the intestinal tract, but possibly other gastrointestinal and extraintestinal organs. Although etiology is still uncertain, recent knowledge in pathogenesis has accumulated, and novel diagnostic and therapeutic modalities have become available for clinical use. Therefore, the previous guidelines were urged to be updated. In 2016, the Japanese Society of Gastroenterology revised the previous versions of evidence-based clinical practice guidelines for ulcerative colitis (UC) and Crohn's disease (CD) in Japanese. A total of 59 clinical questions for 9 categories (1. clinical features of IBD; 2. diagnosis; 3. general consideration in treatment; 4. therapeutic interventions for IBD; 5. treatment of UC; 6. treatment of CD; 7. extraintestinal complications; 8. cancer surveillance; 9. IBD in special situation) were selected, and a literature search was performed for the clinical questions with use of the MEDLINE, Cochrane, and Igaku Chuo Zasshi databases. The guidelines were developed with the basic concept of the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system. Recommendations were made using Delphi rounds. This English version was produced and edited based on the existing updated guidelines in Japanese.

Rac Attack: Modulation of the Small GTPase Rac in Inflammatory Bowel Disease and Thiopurine Therapy

The incidence and prevalence of inflammatory bowel disease (IBD) are increasing. Although the etiology of IBD is unknown, it is thought that genetically susceptible individuals display an inappropriate inflammatory response to commensal microbes, resulting in intestinal tissue damage. Key proteins involved in regulating the immune response, and thus in inflammation, are the small triphosphate-binding protein Rac and its regulatory network. Recent data suggest these proteins to be involved in (dys)regulation of the characteristic inflammatory processes in IBD. Moreover, Rac-gene variants have been identified as susceptibility risk factors for IBD, and Rac1 GTPase signaling has been shown to be strongly suppressed in non-inflamed mucosa compared with inflamed colonic mucosa in IBD. In addition, first-line immunosuppressive treatment for IBD includes thiopurine therapy, and its immunosuppressive effect is primarily ascribed to Rac1 suppression. In this review, we focus on Rac modification and its potential role in the development of IBD, Rac as the molecular therapeutic target in current thiopurine therapy, and the modulation of the Rac signal transduction pathway as a promising novel therapeutic strategy.

Hepatic complications induced by immunosuppressants and biologics in inflammatory bowel disease

The incidence of inflammatory bowel diseases (IBD) is rising worldwide. The therapeutic options for IBD are expanding, and the number of drugs with new targets will rapidly increase in coming years. A rapid step-up approach with close monitoring of intestinal inflammation is extensively used. The fear of side effects represents one the most limiting factor of their use. Despite a widespread use for years, drug induced liver injury (DILI) management remains a challenging situation with Azathioprine and Methotrexate. DILI seems less frequent with anti-tumor necrosis factor agents and new biologic therapies. The aim of this review is to report incidence, physiopathology and practical guidelines in case of DILI occurrence with the armamentarium of old and new drugs in the field of IBD.

A rolling phenotype in Crohn's disease

Background and aim

The Montreal classification of disease behaviour in Crohn's disease describes progression of disease towards a stricturing and penetrating phenotype. In the present paper, we propose an alternative representation of the long-term course of Crohn’s disease complications, the rolling phenotype. As is commonly observed in clinical practice, this definition allows progression to a more severe phenotype (stricturing, penetrating) but also, regression to a less severe behaviour (inflammatory, or remission) over time.

Methods

All patients diagnosed with Crohn's Disease between 01/01/1994 and 01/03/2008, managed at a single centre and observed for a minimum of 5 years, had development and resolution of all complications recorded. A rolling phenotype was defined at each time point based on all observed complications in the three years prior to the time point. Phenotype was defined as B1, B2, B3, or B23 (penetrating and stenotic). The progression over time of the rolling phenotype was compared to that of the cumulative Montreal phenotype.

Results

305 patients were observed a median of 10.0 (Intraquartile range 7.3–13.7) years. Longitudinal progression of rolling phenotype demonstrated a consistent proportion of patients with B1 (70%), B2 (20%), B3 (5%) and B23 (5%) phenotypes. These proportions were observed regardless of initial phenotype. In contrast, the cumulative Montreal phenotype progressed towards a more severe phenotype with time (B1 (39%), B2 (26%), B3(35%) at 10 years).

Conclusion

A rolling phenotype provides an alternative view of the longitudinal burden of intra-abdominal complications in Crohn's disease. From this viewpoint, 70% of patients have durable freedom from complication over time (>3 years).

AZALEP a randomized controlled trial of azathioprine to treat leprosy nerve damage and Type 1 reactions in India: Main findings

Background

Leprosy Type 1 reactions are difficult to treat and only 70% of patients respond to steroid treatment. Azathioprine has been used as an immune-suppressant and we tested its efficacy in treating leprosy T1R.

Methodology

Randomised controlled trial adding azathioprine to steroid treatment for leprosy reactions. This trial was conducted in four leprosy hospitals in India. Patients with a new leprosy Type 1 reaction affecting either skin or nerve were recruited. They were given a 20 week course of oral prednisolone either with placebo or azathioprine 50mg for 24, 36 or 48 weeks. Outcomes were measured using a verified combined clinical reaction severity score (CCS) and the score difference between baseline and end of study calculated. An intention to treat analysis was done on the 279 patients who had an outcome.

Principal findings

345 patients were recruited, 145 were lost due to adverse events, loss to follow up or death. 36% needed extra steroids due to a recurrence of their skin and/or nerve reaction. 76% of patients had improvements in their CCS the end of the study, 22% had no change and 1.1% deteriorated. Adding azathioprine to steroid treatment did not improve CCS. So the improvements were attributable to treatment with steroids. We analysed the skin, sensory and motor scores separately and found that skin improvement contributed most with 78.9% of patients having skin improvement, azathioprine treatment for 48 weeks improved sensory scores it also improved motor scores but so did treatment with prednisolone alone. We identified significant adverse effects attributable to steroid treatment. When azathioprine and Dapsone were given together significant numbers of patients developed significant anaemia.

Conclusions

Azathioprine is not recommended for the treatment of leprosy reactions and does not improve steroid treatment. Recurrent reactions are a major challenge. We have also identified that 65% of patients with sensory and 50% with motor nerve damage do not improve. Future studies should test giving azathioprine in the treatment of nerve damage and giving a higher dose for 48 weeks to patients. These findings highlight the difficulty in switching off leprosy inflammation and the need for better treatments for reactions and nerve damage. There is also a research need to identify patients who have recurrences and optimize treatments for them. Patients with recurrences may benefit from combined treatment with steroids and azathioprine. We have also shown that significant numbers of patients treated with steroids develop adverse effects and this needs to be highlighted in leprosy programmes. Research is needed to identify patients who do not respond to steroid treatment and develop alternative treatments for them.

Trial Registration

ClinicalTrials.gov This trial was registered with the Indian Council of Medical research clinical Trial register as a clinical trial Number—REFCTRI/2016/12/007558

Type 1 reactions affect leprosy patients and are due to increased inflammation in skin and nerves that can cause disfiguring skin lesions and loss of sensation and loss of power in the hands and the feet. These disabilities can lead to deformity and severe disability. It is important to improve the treatment for T1 reactions. T1R are currently treated with steroid tablets and about 50% patients will have improvement in their nerve function after treatment. Azathioprine is a cheap widely available immune-suppressant and we tested whether it could improve skin and nerve function in leprosy patients. We did a randomised double blind study in four leprosy hospitals in India giving 345 patients treatment with steroids plus either azathioprine or placebo. 78% of patients had improved skin, 35% had improved sensory and 50% had improved motor nerve function at the end of treatment. Treatment with azathioprine did not increase patient improvement and the improvements we found were associated with steroid treatment. There was a high rate of adverse effects from both steroids and azathioprine. These findings highlight the difficulty in switching off leprosy inflammation and the need for better treatments for reactions and nerve damage. The problems of steroids causing adverse effects in patients needs to be highlighted in leprosy programmes. Research is needed to identify patients who do not respond to steroid treatment and develop alternative treatments for them.

Monitoring thiopurine metabolites in inflammatory bowel disease

Thiopurines (azathioprine and mercaptopurine) are one of the immunosuppressive mainstays for the treatment of inflammatory bowel disease. In spite of its widespread use, thiopurine metabolism is still not fully understood, and a significant proportion of patients suffer toxicity or lack of efficacy. Different enzymatic pathways with individual variations constitute a pharmacogenetic model that seems to be suitable for monitoring and therapeutic intervention. This review is focused on current concepts and recent research that may help clinicians to rationally optimise thiopurine treatment in patients with inflammatory bowel disease.

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

BACKGROUND

The therapeutic role of 6-mercaptopurine (6-MP) and azathioprine (AZA) remains controversial due to their perceived relatively slow-acting effect and adverse effects. An updated meta-analysis was performed to evaluate the efficacy of these agents for the maintenance of remission in quiescent Crohn's disease.

OBJECTIVES

To assess the efficacy of AZA and 6-MP for maintenance of remission in quiescent Crohn's disease.

SEARCH METHODS

We searched MEDLINE, EMBASE, and the Cochrane Library from inception to June 30, 2015.

SELECTION CRITERIA

Randomized controlled trials of oral azathioprine or 6-mercaptopurine compared to placebo or active therapy involving adult patients (> 18 years) with quiescent Crohn's disease were considered for inclusion. Patients with surgically-induced remission were excluded.

DATA COLLECTION AND ANALYSIS

At least two authors independently extracted data and assessed study quality using the Cochrane risk of bias tool. For dichotomous outcomes, we calculated the risk ratio (RR) and corresponding 95% confidence interval (CI). The primary outcomes was maintenance of remission. Secondary outcomes included steroid sparing, adverse events, withdrawals due to adverse events and serious adverse events. All data were analyzed on an intention-to-treat basis. The overall quality of the evidence supporting the primary outcome and selected secondary outcomes was assessed using the GRADE criteria.

MAIN RESULTS

Eleven studies (881 participants) were included. Comparisons included AZA versus placebo (7 studies, 532 participants), AZA or 6-MP versus mesalazine or sulfasalazine (2 studies, 166 participants), AZA versus budesonide (1 study, 77 participants), AZA and infliximab versus infliximab (1 study, 36 patients), 6-MP versus methotrexate (1 study, 31 patients), and early AZA versus conventional management (1 study, 147 participants). Two studies were rated as low risk of bias. Three studies were rated as high risk of bias for being non-blinded. Six studies were rated as unclear risk of bias. A pooled analysis of six studies (489 participants) showed that AZA (1.0 to 2.5 mg/kg/day) was significantly superior to placebo for maintenance of remission over a 6 to 18 month period. Seventy-three per cent of patients in the AZA group maintained remission compared to 62% of placebo patients (RR 1.19, 95% CI 1.05 to 1.34). The number needed to treat for an additional beneficial outcome was nine. A GRADE analysis indicated that the overall quality of the evidence supporting this outcome was low due to sparse data (327 events) and unclear risk of bias. A pooled analysis of two studies (166 participants) showed no statistically significant difference in the proportion of patients who maintained remission between AZA (1.0 to 2.5 mg/kg/day) or 6-MP (1.0 mg/day) and mesalazine (3 g/day) sulphasalazine (0.5 g/15 kg) therapy. Sixty-nine per cent of patients in the AZA/6-MP group maintained remission compared to 67% of mesalazine/sulphasalazine patients (RR 1.09, 95% CI 0.88 to 1.34). A GRADE analysis indicated that the overall quality of the evidence supporting this outcome was low due to sparse data (113 events) and high or unclear risk of bias. One small study found AZA (2.0 to 2.5 mg/kg/day) to be superior to budesonide (6 to 9 mg/day) for maintenance of remission at one year. Seventy-six per cent (29/38) of AZA patients maintained remission compared to 46% (18/39) of budesonide patients (RR 1.65, 95% CI 1.13 to 2.42). GRADE indicated that the overall quality of the evidence supporting this outcome was low due to sparse data (47 events) and high risk of bias. One small study found no difference in maintenance of remission rates at one year between combination therapy with AZA (2.5 mg/kg) and infliximab (5 mg/kg every 8 weeks) compared to infliximab monotherapy. Eighty-one per cent (13/16) of patients in the combination therapy group maintained remission compared to 80% (16/20) of patients in the infliximab group (RR 1.02, 95% CI 0.74 to 1.40). GRADE indicated that the overall quality of the evidence supporting this outcome was very low due to very sparse data (29 events) and unclear risk of bias. One small study found no difference in maintenance of remission rates at one year between 6-MP (1 mg/day) and methotrexate (10 mg/week). Fifty per cent (8/16) of 6-MP patients maintained remission at one year compared to 53% (8/15) of methotrexate patients (RR 0.94, 95% CI 0.47 to 1.85). GRADE indicated that the overall quality of the evidence supporting this outcome was very low due to very sparse data (16 events) and high risk of bias. One study (147 participants) failed to show any significant benefit for early azathioprine treatment over a conventional management strategy. In the early azathioprine treatment group 67% (11-85%) of the trimesters were spent in remission compared to 56% (29-73%) in the conventional management group. AZA when compared to placebo had significantly increased risk of adverse events (RR 1.29, 95% CI 1.02 to 1.64), withdrawal due to adverse events (3.12, 95% CI 1.59 to 6.09) and serious adverse events (RR 2.45, 95% CI 1.22 to 4.90). AZA/6-MP also demonstrated a significantly higher risk of serious adverse events when compared to mesalazine or sulphasalazine (RR 9.37, 95% CI 1.84 to 47.7). AZA/6-MP did not differ significantly from other active therapies with respect to adverse event data. Common adverse events included pancreatitis, leukopenia, nausea, allergic reaction and infection.

AUTHORS' CONCLUSIONS

Low quality evidence suggests that AZA is more effective than placebo for maintenance of remission in Crohn's disease. Although AZA may be effective for maintenance of remission its use is limited by adverse effects. Low quality evidence suggests that AZA may be superior to budesonide for maintenance of remission but because of small study size and high risk of bias, this result should be interpreted with caution. No conclusions can be drawn from the other active comparator studies because of low and very low quality evidence. Adequately powered trials are needed to determine the comparative efficacy and safety of AZA and 6-MP compared to other active maintenance therapies. Further research is needed to assess the efficacy and safety of the use of AZA with infliximab and other biologics and to determine the optimal management strategy for patients quiescent Crohn's disease.

Optimal Endpoint of Therapy in IBD: An Update on Factors Determining a Successful Drug Withdrawal

Ulcerative colitis (UC) and Crohn's disease (CD) are chronic inflammatory disorders, which require long term treatment to achieve remission and to prevent relapses and cancer. While current therapies are effective in most cases, they can have rare but serious side effects and are often associated with high costs. On the other hand, early discontinuation of an effective treatment may lead to a quick relapse and to complications at the restart of therapy. Therefore it is essential to determine the optimal duration of maintenance therapy, but clear guidelines are missing. The most important questions when deciding whether to continue or withdraw therapy in quiescent UC and CD patients are the efficacy of the continuous treatment to maintain remission in the long term, the frequency and severity of side effects, and the chance of relapse after discontinuation of therapy. This review summarizes the current knowledge on these topics with respect to 5-aminosalicylates, thiopurines, methotrexate, and biological therapies and collects information regarding when and in which specific patient groups, in the absence of risk factors, can withdrawal of therapy be considered without a high risk of relapse. Additionally, the particular aspect of colorectal cancer prevention by current therapies will also be discussed.

Optimization of the treatment with immunosuppressants and biologics in inflammatory bowel disease

Many placebo controlled trials and meta-analyses evaluated the efficacy of different drugs for the treatment of inflammatory bowel disease (IBD), including immunosuppressants and biologics. Their use is indicated in moderate to severe disease in non responders to corticosteroids and in steroid-dependent patients, as induction and maintainance treatment. Infliximab, as well as cyclosporine, is considered a second line therapy in the case of severe ulcerative colitis, or non-responders to intravenous corticosteroids. An adequate dosage and duration of therapy with thiopurines should be reached before evaluating their efficacy. Methotrexate is a valid option in patients with Crohn's disease but its use is confined to patients who are intolerant or non-responders to thiopurines. Evidence for the use of methotrexate in ulcerative colitis is insufficient. The use of thalidomide and mycophenolate mofetil is not recommended in patients with inflammatory bowel disease, these treatments could be considered in case of failure of all other therapeutic options. In patients with moderately active ulcerative colitis, refractory to thiopurines, the use of tacrolimus is considered an alternative to biologics. An increase of the dose or a decrease in the interval of administration of biological treatment could be useful in the presence of an incomplete clinical response. In the case of primary failure of an anti-tumor necrosis factor alpha a switch to another one should be considered. Data on the efficacy of combination therapy are up to now insufficient to consider this strategy in all IBD patients. The final outcome of the treatment should be considered the clinical remission, with mucosa healing, and not the clinical response. The evaluation of serum concentration of thiopurine methyl transferase activity, thiopurine metabolites, biologic serum levels and antibiologic antibodies could be useful for the management of the treatment but it has not been routinely applied in clinical practice. The evidence of high risk development of lymphoma and cutaneous malignancies should be considered in patients treated with immunosuppressants and biologics for a long period.

Psychiatric comorbidity in the treatment of patients with inflammatory bowel disease

Ulcerative colitis and Crohn’s disease, commonly known as inflammatory bowel disease (IBD), draw attention from specialists of various disorders, including gastroenterology, psychiatry, and radiology. The involvement of a cortical influence in the brain-gut axis as well as the interaction of the hypothalamic-pituitary-adrenal axis and the peripheral nervous system provide an initial explanation of the psychological symptoms associated with IBD. The involvement of structures the limbic system, such as the anterior cingulate cortex, the prefrontal cortex, and the amygdala, paves the way for the discovery of the mechanisms underlying depression depression, anxiety, alexithymia, personality traits, and other psychological impairments following the onset of IBD. Psychiatric therapy in IBD patients is almost as important as the gastroenterological approach and consists of pharmacological treatment and psychotherapy. Neither of the available psychiatric treatment methods is considered the golden standard because both methods have side effects, and psychotropic medication can provoke the worsening of IBD symptoms. Thus, both approaches must be applied with awareness of the possibility of side effects. We suggest that psychiatrists and gastroenterologists work together to reach a consensus on IBD therapy to ensure success and to reduce side effects and relapse to the lowest possible rates.

Effect of azathioprine intolerance on outcomes of inflammatory bowel disease: a cross-sectional study

BACKGROUND

Azathioprine is well established for the maintenance of remission in patients with inflammatory bowel disease (IBD). However, a significant proportion of patients are intolerant to azathioprine. It is not clear if intolerance of azathioprine is a marker of poor prognosis for patients who will have a more aggressive disease or be more likely to require surgery.

OBJECTIVE

To determine if intolerance to azathioprine is a marker of poor prognosis, indicating patients who have a more aggressive disease course, and to analyse the risk factors and causes of intolerance.

METHODS

A cross-sectional study using the Milton Keynes Hospital IBD database was performed to compare azathioprine-intolerant and azathioprine-tolerant patients.

RESULTS

Two hundred and thirty-nine patients met the inclusion criteria comprising 141 patients with Crohn's disease (CD) and 98 patients with ulcerative colitis (UC). Overall, 28.0% of patients were intolerant to azathioprine. Risk factors for intolerance were female sex and age 50-70 years. Common reasons for intolerance were nausea and vomiting (34.3%), deranged liver function tests (28.4%) and headaches (11.9%). In patients with UC, there was no statistical difference in the disease activity scores between those who were azathioprine intolerant versus tolerant. In patients with CD, azathioprine intolerance was associated with significantly worse disease activity; 25% fewer patients were in clinical remission and 20% more had moderate/severe disease. Rates of surgery were similar between the groups for both UC/CD.

CONCLUSIONS

We conclude that azathioprine intolerance acts as a surrogate marker for patients with CD who in future have poorer symptom control. Azathioprine intolerance marks out a group of patients with CD in whom increased vigilance of symptom control and early escalation of treatment is required.

Practical medical management of Crohn's disease

Crohn's disease is a chronic inflammatory disease of diagnostic and therapeutic challenges. After proper diagnosis, treatment decisions must be made on precise clinical judgment. During the course of the disease there are variable clinical features, so each case must be managed individually. Physicians who care for patients with Crohn's disease should be prepared for treatment options in different states of the disease and possible complications of both the disease and medications. This paper will focus on the management of Crohn's disease. We aim to discuss current treatment options in different presentations of the disease and to provide algorithmic management strategy.

Top-down or step-up treatment in Crohn's disease?

In recent years, a change in the treatment goals for patients with Crohn's disease (CD) has come under intense discussion. Whereas 10 years ago treatment was initiated mainly in reaction to acute flares of the disease aimed to improve clinical symptoms, the focus now has changed to the prevention of damage to the intestinal wall. The prevention of structural damage by achievement of 'mucosal healing', however, is associated with the more 'aggressive' treatment and an earlier use of immunosuppressants and biologicals. The use of immunosuppressants and biologicals especially in patients with CD has decreased the rates of surgery and hospitalizations, indicating that there is a group of patients definitely profiting from such an early use of immunosuppressive treatment. In this group of patients, the benefits outweigh the disadvantages of immunosuppression: the increased risk of severe infections. However, it remains questionable whether this improvement can only be achieved by completely reversing established treatment strategies. The dispute has been condensed to the questions whether 'top-down' (e.g. start with a combination of biological and immunosuppressant and 'de-escalate' if possible) or 'step-up' treatment (e.g. start with topical steroids, step up to systemic steroid, go to immunosuppression and biologicals if necessary) may be better. In general, in an upcoming era of individualized and personalized medicine, a 'one-size-fits-all' approach does not appear to be desirable. CD patients definitely should not be undertreated (which is still frequently the case) or remain on steroid treatment (which is inappropriate); however, overtreatment (putting patients at risk of side effects without benefit) is against a fundamental principle of medicine: nihil nocere (do no harm).

Evidence-based clinical practice guidelines for Crohn's disease, integrated with formal consensus of experts in Japan

Crohn's disease is a disorder of unknown etiology and complicated pathogenesis. A substantial amount of evidence has accumulated recently and has been applied to clinical practice. The present guidelines were developed based on recent evidence and the formal consensus of experts relevant to this disease. Here we provide an overview of these guidelines, as follows. Target disease: Crohn's disease Users: Clinical practitioners in internal medicine, surgery, gastroenterology, and general practice Purpose: To provide appropriate clinical indicators to practitioners Scope of clinical indicators: Concept of Crohn's disease, epidemiology, classifications, diagnosis, treatment, follow up, and special situations Intervention: Diagnosis (interview, physical examination, clinical laboratory tests, imaging, and pathology) and treatment (lifestyle guidance, drug therapy, nutritional therapy, surgery, etc.) Outcome assessment: Attenuation of symptoms, induction and maintenance of remission, imaging findings, quality of life (QOL), prevention of complications and harm of therapy Methods for developing these guidelines: Described in the text Basis of recommendations: Integration of evidence level and consensus of experts Cost-benefit analysis: Not implemented Evaluation of effectiveness: Yet to be confirmed Status of guidelines: Updated version of the first Guidelines published in 2010 Publication sources: Printed publication available and electronic information in preparation Patient information: Not available Date of publication: October 2011 These guidelines were intended primarily to be used by practitioners in Japan, and the goal of these guidelines is to improve the outcomes of patients with Crohn's disease.

The long-term risk of continuous immunosuppression using thioguanides in inflammatory bowel disease

The efficacy of thiopurine treatment in the induction, and especially maintenance, of remission in inflammatory bowel disease is well proven; however, it is associated with side effects in both medium and long-term use. The potential harmful effects may be anticipated and minimised by due diligence prior to commencing these drugs followed by close monitoring of haematological and biochemical parameters once started. Careful clinical examination and history taking are also essential. Affected patients are expected to lead lives that include travel, employment and pregnancy - the implications of continued thiopurine therapy in such patients are discussed.

Update on the management of Crohn's disease

Crohn's disease (CD) is a chronic inflammatory disorder characterized by focal, asymmetric, transmural inflammation of any part of the luminal gastrointestinal tract of uncertain etiology and an unpredictable course. The available treatment options include aminosalicylates, budesonide and systemic corticosteroids, antibiotics, immunomodulators,methotrexate and anti-TNF agents. This review discusses recent developments in the treatment of CD and provides a comprehensive update on management of patients with CD based on the data from randomized controlled trials.

Optimizing 6-mercaptopurine and azathioprine therapy in the management of inflammatory bowel disease

The thiopurine drugs, 6-mercaptopurine (6-MP) and azathioprine, are efficacious in the arsenal of inflammatory bowel disease (IBD) therapy. Previous reports indicate that 6-thioguanine nucleotide (6-TGN) levels correlate with therapeutic efficacy, whereas high 6-methylmercaptopurine (6-MMP) levels are associated with hepatotoxicity and myelotoxicity. Due to their complex metabolism, there is wide individual variation in patient response therein, both in achieving therapeutic drug levels as well as in developing adverse reactions. Several strategies to optimize 6-TGN while minimizing 6-MMP levels have been adopted to administer the thiopurine class of drugs to patients who otherwise would not tolerate these drugs due to side-effects. In this report, we will review different approaches to administer the thiopurine medications, including the administration of 6-mercaptopurine in those unsuccessfully treated with azathioprine; co-administration of thiopurine with allopurinol; co-administration of thiopurine with anti-tumor necrosis factor α; 6-TGN administration; desensitization trials; and split dosing of 6-MP.

Common misconceptions about 5-aminosalicylates and thiopurines in inflammatory bowel disease

Misconceptions are common in the care of patients with inflammatory bowel disease (IBD). In this paper, we state the most commonly found misconceptions in clinical practice and deal with the use of 5-aminosalicylates and thiopurines, to review the related scientific evidence, and make appropriate recommendations. Prevention of errors needs knowledge to avoid making such errors through ignorance. However, the amount of knowledge is increasing so quickly that one new danger is an overabundance of information. IBD is a model of a very complex disease and our goal with this review is to summarize the key evidence for the most common daily clinical problems. With regard to the use of 5-aminosalicylates, the best practice may to be consider abandoning the use of these drugs in patients with small bowel Crohn’ s disease. The combined approach with oral plus topical 5-aminosalicylates should be the first-line therapy in patients with active ulcerative colitis; once-daily treatment should be offered as a first choice regimen due to its better compliance and higher efficacy. With regard to thiopurines, they seem to be as effective in ulcerative colitis as in Crohn’ s disease. Underdosing of thiopurines is a form of undertreatment. Thiopurines should probably be continued indefinitely because their withdrawal is associated with a high risk of relapse. Mercaptopurine is a safe alternative in patients with digestive intolerance or hepatotoxicity due to azathioprine. Finally, thiopurine methyltransferase (TPMT) screening cannot substitute for regular monitoring because the majority of cases of myelotoxicity are not TPMT-related.

Role of conventional therapies in the era of biological treatment in Crohn’s disease

Outstanding progress regarding the pathophysiology of Crohn’s disease (CD) has led to the development of innovative therapeutic concepts. Numerous controlled trials have been performed in CD. This review concentrates on the results of randomized, placebo-controlled trials, and meta-analyses when available, that provide the highest degree of evidence. Current guidelines on the management of CD recommend a step-up approach to treatment involving the addition of more powerful therapies as the severity of disease and refractoriness to therapy increase. The advent of biological drugs has opened new therapeutic horizons for treating CD, modifying the treatment goals. However, the large majority of patients with CD will be managed through conventional therapy, even if they are a prelude to biological therapy.

Allopurinol might improve response to azathioprine and 6-mercaptopurine by correcting an unfavorable metabolite ratio

BACKGROUND AND AIM

Allopurinol potentiates azathioprine and 6-mercaptopurine (6-MP) by increasing 6-thioguanine nucleotide (6-TGN) metabolite concentrations. The outcome might also be improved by adding allopurinol in individuals who preferentially produce 6-methylmercaptopurine nucleotides (6-MMPN), rather than 6-TGN. The aim of the present study was to investigate the effect of allopurinol on concentrations of 6-MMPN and 6-TGN in individuals with a high ratio of these metabolites (>20), which is indicative of a poor thiopurine response.

METHODS

Sixteen individuals were identified who were taking azathioprine or 6-MP, and were commenced on allopurinol to improve a high 6-MMPN:TGN ratio. Metabolite concentrations were compared before and after commencing allopurinol, and markers of disease control were compared.

RESULTS

The addition of 100-300 mg allopurinol daily and thiopurine dose reduction (17-50% of the original dose) resulted in a reduction of the median (and range) 6-MMPN concentration, from 11,643 (3,365-27,832) to 221 (55-844) pmol/8×10(8) red blood cells (RBC; P=0.0005), increased 6-TGN from 162 (125-300) to 332 (135-923) pmol/8×10(8) RBC (P=0.0005), and reduced the 6-MMPN:6-TGN ratio from 63 (12-199) to 1 (0.1-4.5) (P=0.0005). There was a significant reduction in steroid dose requirements at 12 months (P=0.04) and trends for improvement in other markers of disease control. One patient developed red cell aplasia that resolved upon stopping azathioprine and allopurinol.

CONCLUSIONS

In those with a high 6-MMPN:6-TGN ratio (>20), response to thiopurine treatment might be improved by the addition of allopurinol, together with a reduced thiopurine dose and close hematological monitoring.

Inflammatory bowel disease in the elderly

Although inflammatory bowel disease (IBD) is generally considered a disease of young adults, it can occur in elderly individuals. The clinical features and treatment considerations in older patients are similar to those in younger patients, with some notable exceptions, which are reviewed in this article. Consideration of appropriate differential diagnoses is critical in older IBD patients to achieve the correct diagnosis and appropriate therapy. The risks associated with use of some IBD medications may be increased in older patients, but so is the risk of under-treated IBD and surgery. Therefore, in older IBD patients, as in younger patients, a thorough understanding of the indications, contraindications, and potential adverse effects of the various medications used to treat the condition is essential.

[Clinical practice guideline on diagnosis and treatment of Crohn's disease - summary for the general practitioner]

The German clinical practice guideline on diagnosis and therapy of Crohn's disease is the result of an evidence-based consensus conference under the auspices of the German Gastroenterologic Society and the Competence Network IBD. This article will summarize the recommendations most important for the general practitioner.Crohn's disease is diagnosed in cooperation with a gastroenterologist who is performing endoscopy and possibly ultrasound. Uncomplicated relapses can nevertheless be successfully treated at the office of a family physician - mostly with steroids. Steroids are not appropriate for long-term treatment though. In those cases an early treatment with immunosuppressants in collaboration with a gastroenterologist is required. Cooperation with several different sub specialists is necessary when surgery is required as well as for the treatment of fistula, psychosomatic aspects and extraintestinal manifestations.

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

BACKGROUND

The therapeutic role of 6-mercaptopurine and azathioprine remains controversial due to their perceived relatively slow-acting effect and adverse effects. A meta-analysis was performed to evaluate the efficacy of these agents for the maintenance of remission of quiescent Crohn's disease.

OBJECTIVES

To assess the efficacy of azathioprine and 6-mercaptopurine for maintenance of remission in quiescent Crohn's disease.

SEARCH STRATEGY

Pertinent studies were selected using the MEDLINE data base (1966-May 1998), the Cochrane Controlled Trials Register, the Inflammatory Bowel Disease register, as well as abstracts from major gastrointestinal research meetings and references from published articles and review. This search strategy was updated (1998-May 2008) using the MEDLINE, EMBASE and International Pharmaceutical Abstracts databases, the Cochrane Central 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 quiescent Crohn's disease.

DATA COLLECTION AND ANALYSIS

Data were extracted by three independent observers (EP, MC, LRS) based on the intention to treat principle. Peto odds ratios and 95% confidence intervals for maintenance of remission, steroid sparing, and withdrawals due to adverse effects were calculated. Numbers needed to treat or harm (NNT, NNH respectively) for the maintenance of remission, steroid sparing, and withdrawals due to adverse effects were also determined.

MAIN RESULTS

Seven trials of azathioprine therapy and one of 6-mercaptopurine were included in the review. Azathioprine and 6-mercaptopurine had a positive effect on maintaining remission. The Peto odds ratio (OR) for maintenance of remission with azathioprine was 2.32 (95% CI 1.55 to 3.49) with a NNT of 6. The Peto OR for maintenance of remission with 6-mercaptopurine was 3.32 (95% CI 1.40 to 7.87) with a of 4. Higher doses of azathioprine improved response. A steroid sparing effect with azathioprine was noted, with a Peto OR of 5.22 (95% CI 1.06 to 25.68) and NNT of 3 for quiescent disease. Withdrawals due to adverse events were more common in patients treated with azathioprine (Peto OR 3.74; 95% CI 1.48 to 9.45, NNH = 20) than with placebo.

AUTHORS' CONCLUSIONS

Azathioprine and 6-mercaptopurine are more effective than placebo for maintenance of remission in Crohn's disease. Higher response rates were obtained with azathioprine than 6-mercaptopurine. However, the one study evaluating 6-mercaptopurine used a relatively low dose of the drug. Future studies should look at the effect of higher doses of 6-mercaptopurine. There is weak evidence for a steroid sparing effect with azathioprine treatment.

Postoperative Crohn’s disease recurrence: A practical approach

Crohn's disease is a chronic inflammatory condition that may involve any segment of the gastrointestinal tract. Although several drugs have proven efficacy in inducing and maintaining disease in remission, resectional surgery remains as a cornerstone in the management of the disease, mainly for the treatment of its stenosing and penetrating complications. However, the occurrence of new mucosal (endoscopic) lesions in the neoterminal ileum early after surgery is almost constant, it is followed in the mid-term by clinical symptoms and, in a proportion of patients, repeated intestinal resections are required. Pathogenesis of postoperative recurrence (POR) is not fully understood, but luminal factors (commensal microbes, dietary antigens) seem to play an important role, and environmental and genetic factors may also have a relevant influence. Many studies tried to identify clinical predictors for POR with heterogeneous results, and only smoking has repeatedly been associated with a higher risk of POR. Ileocolonoscopy remains as the gold standard for the assessment of appearance and severity of POR, although the real usefulness of the available endoscopic score needs to be revisited and alternative techniques are emerging. Several drugs have been evaluated to prevent POR with limited success. Smoking cessation seems to be one of the more beneficial therapeutic measures. Aminosalicylates have only proved to be of marginal benefit, and they are only used in low-risk patients. Nitroimidazolic antibiotics, although efficient, are associated with a high rate of intolerance and might induce irreversible side effects when used for a long-term. Thiopurines are not widely used after ileocecal resection, maybe because some concerns in giving immunomodulators in asymptomatic patients still remain. In the era of biological agents and genetic testing, a well-established preventive strategy for POR is still lacking, and larger studies to identify good clinical, serological, and genetic predictors of early POR as well as more effective drugs (or drug combinations) are needed.

Are we giving azathioprine too late? The case for early immunomodulation in inflammatory bowel disease

Inflammatory bowel disease (IBD) includes two entities, Crohn’s disease and ulcerative colitis. Both are chronic conditions with frequent complications and surgical procedures and a great impact on patient’s quality of life. The thiopurine antimetabolites azathioprine and 6-mercaptopurine are widely used in IBD patients. Current indications include maintenance therapy, steroid-dependant disease, fistula closure, prevention of infliximab immunogenicity and prevention of Crohn’s disease recurrence. Surprisingly, the wide use of immunosuppressants in the last decades has not decreased the need of surgery, probably because these treatments are introduced at too late stages in disease course. An earlier use of immunossupressants is now advocated by some authors. The rational includes: (1) failure to modify IBD natural history of present therapeutic approach, (2) demonstration that azathioprine can induce mucosal healing, a relevant prognostic factor for Crohn’s disease and ulcerative colitis, and (3) demonstration that early immunossupression has a very positive impact on pediatric, recently diagnosed Crohn’s disease patients. We are now awaiting the results of new studies, to clarify the contribution of azathioprine, as compared to infliximab (SONIC Study), and to demonstrate the usefulness of azathioprine in recently diagnosed adult Crohn’s disease patients (AZTEC study).

Are we giving azathioprine too much time?

Azathioprine is currently the key drug in the maintenance treatment of inflammatory bowel diseases. However, there are still some practical issues to be resolved: one is how long we must maintain the drug. Given that inflammatory bowel diseases are to date chronic, non-curable conditions, treatment should be indefinite and only the loss of efficacy or the appearance of serious side effects may cause withdrawal. As regards to efficacy and their maintenance over time, evidence supports the continuous usefulness of the drug in the long term: in fact its withdrawal very substantially increases the risk of relapse. About side effects, azathioprine is a relatively well tolerated drug and even indefinite use seems safe. The main theoretical risks of prolonged use would be the myelotoxicity, hepatotoxicity, and the development of cancer. In fact, serious bone marrow suppression or serious liver damage are uncommon, and can be minimized with proper use of the drug. Recent metanalysis suggests that the risk of lymphoma is real, but the individual risk is rather low, and decision analysis suggests a favorable benefit/risk ratio in the long term. Therefore, in patients with inflammatory bowel diseases in whom azathioprine is effective and well tolerated, the drug should not be stopped. This recommendation concerns the use of azathioprine as a single maintenance drug, and is not necessarily applicable to patients receiving concomitant biological therapy.

Crohn's disease: a review of current treatment with a focus on biologics

Crohn's disease is a debilitating and expensive disease that is growing in incidence in both developing and developed countries. While conventional therapies, such as corticosteroids and immunosuppressants, continue to play a vital role in treating this condition, it is evident that many affected individuals do not respond to therapy or develop intolerable adverse effects. The addition of modern biological therapies to the Crohn's disease armamentarium is providing a change in expectations for disease outcome. Infliximab and adalimumab are currently the only biological agents approved for induction and maintenance treatment in adults (infliximab and adalimumab) and children (infliximab) with Crohn's disease. Furthermore, infliximab has a beneficial effect on perianal fistulas. Other tumour necrosis factor (TNF)-alpha inhibitors, such as certolizumab pegol, also demonstrate promising results in adults with moderate to severe active disease. In addition, adalimumab and certolizumab pegol have shown clinical efficacy in patients who are intolerant to or lose response to infliximab, suggesting that switching between agents may allow response to be maintained over time. The primary safety concerns with TNFalpha inhibitors include increased risk of serious infection (including reactivation of tuberculosis), malignancy (particularly lymphoma) and demyelinating disease. Other agents in development include recombinant human anti-inflammatory cytokines, agents that target pro-inflammatory cytokines and granulocyte-macrophage colony-stimulating factors. Further prospective studies will provide interesting insight into different mechanisms by which factors involved in the pathophysiology of Crohn's disease can be modulated.

Tumor necrosis factor-alpha antibody for maintenance of remission in Crohn's disease

BACKGROUND

Crohn's disease may be refractory to conventional treatments including corticosteroids and immunosuppressives. Recent studies suggest TNF-alpha blocking agents may be effective in maintaining remission in Crohn's disease.

OBJECTIVES

To conduct a systematic review of the evidence for the effectiveness of TNF-alpha blocking agents in the maintenance of remission in patients with Crohn's disease.

SEARCH STRATEGY

MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials and the IBD/FBD Review Group Specialized Trials Register were searched for relevant studies published between 1966-2007. Manual searches of references from potentially relevant papers were performed to identify additional studies. Experts in the field and study authors were contacted to identify unpublished data.

SELECTION CRITERIA

Randomized controlled trials involving patients > 18 years with Crohn's disease who had a clinical response or clinical remission with a TNF-alpha blocking agent, or patients with Crohn's disease in remission but unable to wean corticosteroids, who were then randomized to maintenance of remission with a TNF-alpha blocking agent or placebo

DATA COLLECTION AND ANALYSIS

Two independent authors performed data extraction and assessment of the methodological quality of each trial. Outcome measures reported in the primary studies included clinical remission, clinical response, and steroid-sparing effects.

MAIN RESULTS

Nine studies met all inclusion criteria. Four different anti-TNF-alpha agents were evaluated (infliximab in 3 studies, CDP571 in 3 studies, adalimumab in 2 studies, and certolizumab in 1 study). There is evidence from three randomized controlled trials that infliximab maintains clinical remission (RR 2.50; 95% CI 1.64 to 3.80), maintains clinical response (RR 1.66; 95% CI 1.00 to 2.76), has corticosteroid-sparing effects (RR 3.13; 95% CI 1.25 to 7.81), and maintains fistula healing (RR 1.87; 95% CI 1.15 to 3.04) in patients with Crohn's disease with a response to infliximab induction therapy. There were no significant differences in remission rates between infliximab doses of 5 mg/kg or 10 mg/kg. There is evidence from two randomized controlled trials that adalimumab maintains clinical remission (RR 2.86; 95% CI 2.01 to 4.02), maintains clinical response (RR 2.69; 95% CI 1.88 to 3.86), and has corticosteroid-sparing effects (RR 2.81, 95% CI 1.46 to 5.43) in patients with Crohn's disease who have responded or entered remission with adalimumab induction therapy. There were no significant differences in remission rates between adalimumab 40 mg weekly or every other week. There is evidence from one randomized controlled trial that certolizumab pegol maintains clinical remission (RR 1.68; 95% CI 1.30 to 2.16) and maintains clinical response (RR 1.74; 95% CI 1.41 to 2.13) in patients who have responded to certolizumab induction therapy. There is no evidence to support the use of CDP571 for the maintenance of remission in Crohn's disease.

AUTHORS' CONCLUSIONS

Infliximab 5 mg/kg or 10 mg/kg, given every 8 weeks, is effective for the maintenance of remission and maintenance of fistula healing in patients who have responded to infliximab induction therapy. Adalimumab 40 mg weekly or every other week is effective for the maintenance of remission in patients who have responded to adalimumab induction therapy. Certolizumab pegol 400 mg every 4 weeks is effective for the maintenance of remission in patients who have responded to certolizumab induction therapy. No comparative trials have evaluated the relative efficacy of these agents. Adverse events are similar in the infliximab, adalimumab, and certolizumab groups compared with placebo, but study size and duration generally are insufficient to allow an adequate assessment of serious adverse events associated with long-term use.

Treatment of inflammatory bowel disease: a review of medical therapy

Crohn's disease (CD) and ulcerative colitis (UC) are chronic inflammatory diseases of the gastrointestinal tract. While a cure remains elusive, both can be treated with medications that induce and maintain remission. With the recent advent of therapies that inhibit tumor necrosis factor (TNF) alpha the overlap in medical therapies for UC and CD has become greater. Although 5-ASA agents have been a mainstay in the treatment of both CD and UC, the data for their efficacy in patients with CD, particularly as maintenance therapy, are equivocal. Antibiotics may have a limited role in the treatment of colonic CD. Steroids continue to be the first choice to treat active disease not responsive to other more conservative therapy; non-systemic steroids such as oral and rectal budesonide for ileal and right-sided CD and distal UC respectively are also effective in mild-moderate disease. 6-mercaptopurine (6-MP) and its prodrug azathioprine are steroid-sparing immunomodulators effective in the maintenance of remission of both CD and UC, while methotrexate may be used in both induction and maintenance of CD. Infliximab and adalimumab are anti-TNF agents approved in the US and Europe for the treatment of Crohn's disease, and infliximab is also approved for the treatment of UC.

Review article: the evidence base for interventions used to maintain remission in Crohn's disease

BACKGROUND

Crohn's disease is characterised by recurrent flare-ups alternating with periods of remission. A number of interventions are currently used in clinical practice to try and maintain remission in Crohn's disease but the evidence base for some of them may be questionable.

AIM

To review the available evidence on interventions, which are currently used to maintain remission in Crohn's disease.

METHODS

The Cochrane Library and Medline (Pubmed) were searched for level 1 evidence on specific interventions. Search terms included 'Crohn's disease or synonyms', 'remission or synonyms' and the names of specific interventions.

RESULTS

Azathioprine, infliximab and adalimumab are effective at maintaining remission in Crohn's disease. Natalizumab is also effective, but there are concerns about its potential association with progressive multifocal leukoencephalopathy. Long-term enteral nutritional supplementation, enteric-coated omega-3 fatty acids and intramuscular methotrexate may also be effective but the evidence for these is based on relatively small studies. The available evidence does not support the use of oral 5-aminosalicylates agents, corticosteroids, anti-mycobacterial agents, probiotics or ciclosporin as maintenance therapy in Crohn's disease.

CONCLUSION

A better understanding of the evidence base of existing interventions could result in the use of treatments, which are more likely to lead to improved patient outcomes.

Enteral nutrition for maintenance of remission in Crohn's disease

BACKGROUND

Prevention of relapse is a major issue in the management of Crohn's disease. Corticosteroids and 5-ASA preparations are not effective for the maintenance of remission. Methotrexate, infliximab, 6-mercaptopurine and its prodrug, azathioprine may be effective in maintaining remission, but these drugs may cause significant adverse events.

OBJECTIVES

To conduct a systematic review to evaluate the efficacy of enteral nutrition for the maintenance of remission in Crohn's disease.

SEARCH STRATEGY

MEDLINE (1966 to January 2007), EMBASE (1984 to January 2007) the Cochrane Central Register of Controlled Trials from the Cochrane Library (Issue 4, 2006) and the IBD/FBD Review Group Specialized Trials Register were searched. The articles cited in each publication were hand searched.

SELECTION CRITERIA

Randomised controlled trials which compared enteral nutrition with no intervention, placebo or with any other intervention were eligible for inclusion.

DATA COLLECTION AND ANALYSIS

Data extraction and assessment of methodological quality of included studies were independently performed by two authors. The main outcome measure was the occurrence of clinical or endoscopic relapse as defined by the primary studies. Odds ratios and 95% confidence intervals were calculated for dichotomous outcomes.

MAIN RESULTS

Two studies were identified that met the inclusion criteria and were included in the review. Statistical pooling of the results of these studies was not possible because the control interventions, and the way outcomes were assessed differed greatly between the two studies. In one study (Takagi 2006), patients who received half of their total daily calorie requirements as elemental diet and the remaining half by normal diet had a significantly lower relapse rate compared to patients who received unrestricted normal diet (9 of 26 versus 16 of 25; OR 0.3, 95% CI 0.09 to 0.94). In the other study (Verma 2001), elemental and polymeric feeds (providing between 35 and 50% of patients' pretrial calorie intake in addition to unrestricted normal food) were equally effective for maintenance of remission and allowing withdrawal of steroid therapy (8 of 19 versus 6 of 14; OR 0.97, 95% CI 0.24 to 3.92).

AUTHORS' CONCLUSIONS

The available evidence suggests that supplementary enteral nutritional may be effective for maintenance of remission in Crohn's disease. Whilst larger studies are needed to confirm these findings, enteral nutritional supplementation could be considered as an alternative or as an adjunct to maintenance drug therapy in Crohn's disease.

Omega 3 fatty acids (fish oil) for maintenance of remission in ulcerative colitis

BACKGROUND

Omega-3 fatty acids (n-3, fish oil) have been shown to have anti-inflammatory properties. Therefore, n-3 therapy may be beneficial in chronic inflammatory disorders such as ulcerative colitis.

OBJECTIVES

To systematically review the efficacy and safety of n-3 for maintaining remission in ulcerative colitis (UC).

SEARCH STRATEGY

The following databases were searched from their inception without language restriction: Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, Healthstar, PubMed, and ACP journal club. Experts were contacted for unpublished data.

SELECTION CRITERIA

Randomized placebo-controlled trials (RCT) of fish oil for maintenance of remission in UC were included. Studies must have enrolled patients (of any age group) who were in remission at the time of recruitment, and were followed for at least six months. The intervention must have been fish oil given in pre-defined dosage. Co-interventions were allowed only if they were balanced between the study groups. The primary outcome was relapse rate and the secondary outcome was frequency of adverse events. Other outcomes to assess efficacy were change in disease activity scores and time to first relapse.

DATA COLLECTION AND ANALYSIS

Two independent investigators reviewed studies for eligibility, extracted the data and assessed study quality. Meta-analysis weighted by the Mantel-Haenszel method was performed using RevMan 4.2.8 software. Random or fixed effect models were used according to degree of heterogeneity and subgroup analyses were performed to explore heterogeneity. A sensitivity analysis was performed excluding a study of questionable quality .

MAIN RESULTS

The three studies that were included used different formulation and dosing of n-3 but none used enteric coated capsules. The pooled analysis showed a similar relapse rate in the n-3 treated patients and controls (RR 1.02; 95% CI 0.51 to 2.03; P = 0.96). Combining the studies resulted in virtually no statistical heterogeneity (P = 0.93, I(2) = 0%). Various subgroup and sensitivity analyses showed similar results. However, the total number of patients enrolled in these studies was small (n = 138). No significant adverse events were recorded in any of the studies and not enough data were available to pool the other secondary outcomes for meta-analysis.

AUTHORS' CONCLUSIONS

No evidence was found that supports the use of omega 3 fatty acids for maintenance of remission in UC. Further studies using enteric coated capsules may be justified.

6-Thioguanine Nucleotide–Adapted Azathioprine Therapy Does Not Lead to Higher Remission Rates Than Standard Therapy in Chronic Active Crohn Disease: Results from a Randomized, Controlled, Open Trial

Background: A prospective randomized trial in patients with Crohn disease studied whether 6-thioguanine nucleotide (6-TGN) concentration–adapted azathioprine (AZA) therapy is clinically superior to a standard dose of 2.5 mg/kg/day AZA.

Methods: After 2 weeks of standard therapy, patients (n = 71) were randomized into standard (n = 32) or adapted-dose (n = 25) groups; 14 patients dropped out before randomization. In the adapted group, the AZA dose was adjusted to maintain 6-TGN concentrations between 250 and 400 pmol/8 × 108 erythrocytes (Ery). Response criteria were the number of patients in remission after 16 weeks without steroids (primary) and remission after 24 weeks, frequency of side effects, and quality of life (secondary).

Results: After 16 weeks, 14 of 32 (43.8%) patients in the standard group vs 11 of 25 (44%) in the adapted group were in remission without steroids (intent-to-treat analysis). After 24 weeks, 43.8% vs 40% were in remission. No significant differences were found concerning quality of life, disease activity, 6-TGN concentrations, AZA dose, or dropouts due to side effects. Sixty-six patients had a wild-type thiopurine S-methyltransferase (TPMT) genotype, with TPMT activities of 8 to 20 nmol/(mL Ery × h). Five patients (dropouts after randomization) were heterozygous, with TPMT activities &lt;8 nmol/(mL Ery × h). 6-Methyl mercaptopurine (6-MMP) concentrations &gt;5700 pmol/8 × 108 Ery were not associated with hepatotoxicity.

Conclusion: Standard and adapted dosing with the provided dosing scheme led to identical 6-TGN concentrations and remission rates. Adapted dosing had no apparent clinical benefit for patients with TPMT activity between 8 and 20 nmol/(mL Ery × h). Additionally, 6-MMP monitoring had no predictive value for hepatotoxicity.

Thiopurine treatment in inflammatory bowel disease: clinical pharmacology and implication of pharmacogenetically guided dosing

This review summarises clinical pharmacological aspects of thiopurines in the treatment of chronic inflammatory bowel disease (IBD). Current knowledge of pharmacogenetically guided dosing is discussed for individualisation of thiopurine therapy, particularly to avoid severe adverse effects. Both azathioprine and mercaptopurine are pro-drugs that undergo extensive metabolism. The catabolic enzyme thiopurine S-methyltransferase (TPMT) is polymorphically expressed, and currently 23 genetic variants have been described. On the basis of an excellent phenotype-genotype correlation for TPMT, genotyping has become a safe and reliable tool for determination of a patient's individual phenotype. Thiopurine-related adverse drug reactions are frequent, ranging from 5% up to 40%, in both a dose-dependent and -independent manner. IBD patients with low TPMT activity are at high risk of developing severe haematotoxicity if pharmacogenetically guided dosing is not performed. Based on several cost-benefit analyses, assessment of TPMT activity is recommended prior to thiopurine therapy in patients with IBD. The underlying mechanisms of azathioprine/mercaptopurine-related hepatotoxicity, pancreatitis and azathioprine intolerance are still unknown. Although the therapeutic response appears to be related to 6-thioguanine nucleotide (6-TGN) concentrations above a threshold of 230-260 pmol per 8 x 10(8) red blood cells, at present therapeutic drug monitoring of 6-TGN can be recommended only to estimate patients' compliance.Drug-drug interactions between azathioprine/mercaptopurine and aminosalicylates, diuretics, NSAIDs, warfarin and infliximab are discussed. The concomitant use of allopurinol without dosage adjustment of azathioprine/mercaptopurine leads to clinically relevant severe haematotoxicity due to elevated thiopurine levels. Several studies indicate that thiopurine therapy in IBD during pregnancy is safe. Thus, azathioprine/mercaptopurine should not be withdrawn in strictly indicated cases of pregnant IBD patients. However, breastfeeding is contraindicated during azathioprine/mercaptopurine therapy. Use of azathioprine/mercaptopurine for induction and maintenance of remission in corticosteroid-dependent or corticosteroid-refractory IBD, particularly Crohn's disease, is evidence based. To improve response rates in thiopurine therapy of IBD, comprehensive analyses including metabolic patterns and genome-wide profiling in patients with azathioprine/mercaptopurine treatment are required to identify novel candidate genes.

Practical guidelines for the treatment of inflammatory bowel disease

In recent years, great progress has been made regarding the treatment of inflammatory bowel disease (IBD), particularly in the field of biological therapies. Nevertheless, the ultimate treatment is not in sight. With the development of new medication, it has become clear that we need a new understanding of IBD. Therapy needs to fit the different subtypes of IBD; e.g. mild disease in comparison to severe chronic active disease or Crohn's disease with or without fistulation or stenosis. The following article gives a practical overview of actual treatments for IBD. The intention of this article is not to provide a complete review of all new scientific developments, but to give a practical guideline for therapy of IBD.