Review article: monitoring of immunomodulators in inflammatory bowel disease

Fecal microbiota transplantation and next-generation therapies: A review on targeting dysbiosis in metabolic disorders and beyond

The human microbiome, particularly the gut microbiome, has emerged as a central determinant of health and disease. Dysbiosis, an imbalance in the microbial composition of the gut, is associated with a variety of metabolic and other diseases, highlighting the potential for microbiota-targeted treatments. Fecal microbiota transplantation has received considerable attention as a promising therapy to modulate the gut microbiome and restore microbial homeostasis. However, challenges remain, including standardization, safety, and long-term efficacy. This review summarizes current knowledge on fecal microbiota transplantation and describes the next generation therapies targeting microbiome. This review looked at the mechanistic understanding of fecal microbiota transplantation and alternative strategies, elucidating their potential role in improving dysbiosis-associated metabolic disorders, such as obesity, and type 2 diabetes and others. Additionally, this review discussed the growing application of therapies targeting the gut microbiome. Insights from clinical trials, preclinical studies, and emerging technologies provide a comprehensive overview of the evolving landscape of microbiome-based interventions. Through a critical assessment of current advances and prospects, this review aims to highlight the therapeutic potential of targeting gut microbiome and pave the way for innovative approaches in precision medicine and personalized treatments.

Network meta-analysis and cost-effectiveness analysis of infliximab, cyclosporine and tacrolimus for ulcerative colitis

BACKGROUND

Assess the efficiency and cost-effectiveness of infliximab, cyclosporine and tacrolimus for the treatment of ulcerative colitis (UC).

METHODS

A literature search identified studies that investigated infliximab, cyclosporine or tacrolimus compared with placebo in UC patients. Short-term, long-term remission rates and response rates were employed to assess efficacy. Odds ratios with 95% confidence intervals were analyzed. A Markov model was constructed to simulate the progression in a cohort of patients with UC, with an over 10 years of time horizon, with a discount rate of 3%, and established threshold of €30,000/quality-adjusted life-year (QALY) or ¥82442/QALY.

RESULTS

Results of network meta-analysis showed that the order was cyclosporine, tacrolimus, infliximab and placebo from high rate to low with regard to short-term clinical response. The comparison between infliximab versus cyclosporine achieved an incremental cost effectiveness ratio (ICER) of €184435/QALY and ¥531607/QALY, with a 0.34893 QALYs difference of efficacy, and an incremental cost of €64355 and ¥185494. Tacrolimus versus cyclosporine reached an ICER of €44236/QALY and ¥57494/QALY, with a difference of 0.40963 QALYs in efficacy, and a raising cost to €18120 and ¥23551. The probabilistic sensitivity analysis shows that cyclosporine would be cost-effective in the 75.8% of the simulations, tacrolimus in the 24.2%, and infliximab for the 0%.

CONCLUSION

Infliximab, cyclosporine and tacrolimus as salvage therapies are efficacious. For long-term of clinical remission, the order of pharmacological agents was tacrolimus, infliximab and cyclosporine from high efficacy to low while no significant difference is seen. In cost-effectiveness analysis, the cyclosporine versus infliximab or tacrolimus is expected to be at best.

Cupriavidus necator-Produced Polyhydroxybutyrate/Eudragit FS Hybrid Nanoparticles Mitigates Ulcerative Colitis via Colon-Targeted Delivery of Cyclosporine A

Polyhydroxybutyrate (PHB) has emerged as a novel material for replacing various plastics used in the medical field. However, its application as a drug-delivery carrier for colitis-targeted delivery has not been explored. In this study, we used biosynthesized PHB combined with Eudragit FS (EFS) and cyclosporine A (CSA) to develop pH-responsive controlled CSA-releasing nanoparticles (CSA-PENPs) for colitis-targeted drug delivery and demonstrated its enhanced therapeutic efficacy in a dextran sulfate sodium (DSS)-induced murine colitis model. PHB was successfully biosynthesized in the bacterium Cupriavidus necator, as demonstrated by ¹H-NMR and FT-IR analyses. CSA-PENPs were fabricated via the oil-in-water emulsion solvent evaporation method. Owing to the potent pH-responsive and sustained drug release properties provided by PHB and EFS, CSA-PENPs could deliver a sufficient amount of CSA to inflamed tissues in the distal colon; in contrast, CSA-loaded EFS nanoparticles displayed premature burst release before reaching the target site. Due to enhanced CSA delivery to colitis tissues, CSA-PENPs exhibited potent anti-inflammatory effects in the DSS-induced murine colitis model. Overall, CSA-PENPs could be a promising drug-delivery system for treating ulcerative colitis.

Association of ITPA gene polymorphisms with adverse effects of AZA/6-MP administration: a systematic review and meta-analysis

Azathioprine (AZA) and its metabolite, mercaptopurine (6-MP), are widely used immunosuppressant drugs. Polymorphisms in genes implicated in AZA/6-MP metabolism, reportedly, could account in part for their potential toxicity. In the present study we performed a systematic review and a meta-analysis, comprising 30 studies and 3582 individuals, to investigate the putative genetic association of two inosine triphosphatase (ITPA) polymorphisms with adverse effects in patients treated with AZA/6-MP. We found that rs1127354 is associated with neutropenia in general populations and in children (OR: 2.39, 95%CI: 1.97-2.90, and OR: 2.43, 95%CI: 2.12-2.79, respectively), and with all adverse effects tested herein in adult populations (OR: 2.12, 95%CI: 1.22-3.69). We also found that rs7270101 is associated with neutropenia and leucopenia in all-ages populations (OR: 2.93, 95%CI: 2.36-3.63, and OR: 2.82, 95%CI: 1.76-4.50, respectively) and with all adverse effects tested herein in children (OR: 1.74, 95%CI: 1.06-2.87). Stratification according to background disease, in combination with multiple comparisons corrections, verified neutropenia to be associated with both polymorphisms, in acute lymphoblastic leukemia (ALL) patients. These findings suggest that ITPA polymorphisms could be used as predictive biomarkers for adverse effects of thiopurine drugs to eliminate intolerance in ALL patients and clarify dosing in patients with different ITPA variants.

pH-Responsive Alginate-Based Microparticles for Colon-Targeted Delivery of Pure Cyclosporine A Crystals to Treat Ulcerative Colitis

Cyclosporine A (CsA) is a potent immunosuppressant for treating ulcerative colitis (UC). However, owing to severe systemic side effects, CsA application in UC therapy remains limited. Herein, a colon-targeted drug delivery system consisting of CsA crystals (CsAc)-loaded, Eudragit S 100 (ES)-coated alginate microparticles (CsAc-EAMPs) was established to minimize systemic side effects and enhance the therapeutic efficacy of CsA. Homogeneously-sized CsAs (3.1 ± 0.9 μm) were prepared by anti-solvent precipitation, followed by the fabrication of 47.1 ± 6.5 μm-sized CsAc-EAMPs via ionic gelation and ES coating. CsAc-EAMPs exhibited a high drug loading capacity (48 ± 5%) and a CsA encapsulation efficacy of 77 ± 9%. The in vitro drug release study revealed that CsA release from CsAc-EAMPs was suppressed under conditions simulating the stomach and small intestine, resulting in minimized systemic absorption and side effects. Following exposure to the simulated colon conditions, along with ES dissolution and disintegration of alginate microparticles, CsA was released from CsAc-EAMPs, exhibiting a sustained-release profile for up to 24 h after administration. Given the effective colonic delivery of CsA molecules, CsAc-EAMPs conferred enhanced anti-inflammatory activity in mouse model of dextran sulfate sodium (DSS)-induced colitis. These findings suggest that CsAc-EAMPs is a promising drug delivery system for treating UC.

Clinical Pharmacokinetic and Pharmacodynamic Considerations in the Treatment of Ulcerative Colitis

Ulcerative colitis (UC) is an inflammatory bowel disease (IBD) of unknown etiology, probably caused by a combination of genetic and environmental factors. The treatment of patients with active UC depends on the severity, localization and history of IBD medication. According to the classic step-up approach, treatment with 5-aminosalicylic acid compounds is the first step in the treatment of mild to moderately active UC. Corticosteroids, such as prednisolone are used in UC patients with moderate to severe disease activity, but only for remission induction therapy because of side effects associated with long-term use. Thiopurines are the next step in the treatment of active UC but monotherapy during induction therapy in UC patients is not preferred because of their slow onset. Therapeutic drug monitoring (TDM) of the pharmacologically active metabolites of thiopurines, 6-thioguanine nucleotide (6-TGN), has proven to be beneficial. Thiopurine S-methyltransferase (TMPT) plays a role in the metabolic conversion pathway of thiopurines and exhibits genetic polymorphism; however, the clinical benefit and relevance of TPMT genotyping is not well established. In patients with severely active UC refractory to corticosteroids, calcineurin inhibitors such as ciclosporin A (CsA) and tacrolimus are potential therapeutic options. These agents usually have a rather rapid onset of action. Monoclonal antibodies (anti-tumor necrosis factor [TNF] agents, vedolizumab) are the last pharmacotherapeutic option for UC patients before surgery becomes inevitable. Body weight, albumin status and antidrug antibodies contribute to the variability in the pharmacokinetics of anti-TNF agents. Additionally, the use of concomitant immunomodulators (thiopurines/methotrexate) lowers the rate of immunogenicity, and therefore the concomitant use of anti-TNF therapy with an immunomodulator may confer some advantage compared with monotherapy in certain patients. TDM of anti-TNF agents could be beneficial in patients with primary nonresponse and secondary loss of response. The potential benefit of applying TDM during vedolizumab treatment has yet to be determined.

Nanoparticles for the regulation of intestinal inflammation: opportunities and challenges

Prevalence of chronic inflammation of the gastrointestinal tract is increasing, emerging as a public health challenge. Conventional drug delivery systems targeting the colon have improved the treatment of inflammatory bowel disease. However, therapy frequently results in inconsistent efficacy and toxicity problems. Novel approaches based on nanoparticles offer several advantages over conventional dosage forms due to their ability to selectively target inflamed tissues. Several formulation efforts have been made in order to obtain increasingly selective nanosized systems, some with promising results in animal models of colitis. Despite all advances, no nanomedicines are yet approved for clinical use in inflammatory bowel disease. This review discusses the most recent efforts made toward the development of nanoparticles for regulating chronic intestinal inflammation.

Colon-targeted delivery of cyclosporine A using dual-functional Eudragit® FS30D/PLGA nanoparticles ameliorates murine experimental colitis

Background

Colon-targeted oral nanoparticles (NPs) have emerged as an ideal, safe, and effective therapy for ulcerative colitis (UC) owing to their ability to selectively accumulate in inflamed colonic mucosa. Cyclosporine A (CSA), an immunosuppressive agent, has long been used as rescue therapy in severe steroid-refractory UC. In this study, we developed CSA-loaded dual-functional polymeric NPs composed of Eudragit^® FS30D as a pH-sensitive polymer for targeted delivery to the inflamed colon, and poly(lactic-co-glycolic acid) (PLGA) as a sustained-release polymer.

Methods

CSA-loaded Eudragit FS30D nanoparticles (ENPs), PLGA nanoparticles (PNPs), and Eudragit FS30D/PLGA nanoparticles (E/PNPs) were prepared using the oil-in-water emulsion method. Scanning electron microscope images and zeta size data showed successful preparation of CSA-loaded NPs.

Results

PNPs exhibited a burst drug release of >60% at pH 1.2 (stomach pH) in 0.5 h, which can lead to unwanted systemic absorption and side effects. ENPs effectively inhibited the burst drug release at pH 1.2 and 6.8 (proximal small intestine pH); however, nearly 100% of the CSA in ENPs was released rapidly at pH 7.4 (ileum–colon pH) owing to complete NP dissolution. In contrast to single-functional PNPs and ENPs, the dual-functional E/PNPs minimized burst drug release (only 18%) at pH 1.2 and 6.8, and generated a sustained release at pH 7.4 thereafter. Importantly, in distribution studies in the gastrointestinal tracts of mice, E/PNPs significantly improved CSA distribution to the colon compared with PNPs or ENPs. In a mouse model of colitis, E/PNP treatment improved weight loss and colon length, and decreased rectal bleeding, spleen weight, histological scoring, myeloperoxidase activity, macrophage infiltration, and expression of proinflammatory cytokines compared with PNPs or ENPs.

Conclusion

Overall, this work confirms the benefits of CSA-loaded E/PNPs for efficiently delivering CSA to the colon, suggesting their potential for UC therapy.

EHealth Technologies in Inflammatory Bowel Disease: A Systematic Review

BACKGROUND AND AIMS

Electronic-health technologies (eHealth) such as Web-based interventions, virtual clinics, smart-phone applications, and telemedicine are being used to manage patients with inflammatory bowel disease (IBD). We aimed to: (1) Evaluate the impact of eHealth technologies on conventional clinical indices and patient-reported outcome measures (PROs) in IBD; (2) assess the effectiveness, cost-effectiveness and feasibility of using eHealth technologies to facilitate the self-management of individuals with IBD, and; (3) provide recommendations for their design and optimal use for patient care.

METHODS

Relevant publications were identified via a literature search, and 17 publications were selected based on predefined quality parameters.

RESULTS

Six randomized controlled trials and nine observational studies utilizing eHealth technologies in IBD were identified. Compared with standard outpatient-led care, eHealth technologies have led to improvements in: Relapse duration [(n = 1) 18 days vs 77 days, p < 0.001]; disease activity (n = 2); short-term medication adherence (n = 3); quality of life (n = 4); IBD knowledge (n = 2); healthcare costs (n = 4); the number of acute visits to the outpatient clinic due to IBD symptoms (n = 1), and; facilitating the remote management of up to 20% of an IBD cohort (n = 2). Methodological shortcomings of eHealth studies include heterogeneity of outcome measures, lack of clinician/patient input, lack of validation against conventional clinical indices and PROs, and limited cost-benefit analyses.

CONCLUSIONS

EHealth technologies have the potential for promoting self-management and reducing the impact of the growing burden of IBD on health care resource utilization. A theoretical framework should be applied to the development, implementation, and evaluation of eHealth interventions.

Model-based contextualization of in vitro toxicity data quantitatively predicts in vivo drug response in patients

Understanding central mechanisms underlying drug-induced toxicity plays a crucial role in drug development and drug safety. However, a translation of cellular in vitro findings to an actual in vivo context remains challenging. Here, physiologically based pharmacokinetic (PBPK) modeling was used for in vivo contextualization of in vitro toxicity data (PICD) to quantitatively predict in vivo drug response over time by integrating multiple levels of biological organization. Explicitly, in vitro toxicity data at the cellular level were integrated into whole-body PBPK models at the organism level by coupling in vitro drug exposure with in vivo drug concentration–time profiles simulated in the extracellular environment within the organ. PICD was exemplarily applied on the hepatotoxicant azathioprine to quantitatively predict in vivo drug response of perturbed biological pathways and cellular processes in rats and humans. The predictive accuracy of PICD was assessed by comparing in vivo drug response predicted for rats with observed in vivo measurements. To demonstrate clinical applicability of PICD, in vivo drug responses of a critical toxicity-related pathway were predicted for eight patients following acute azathioprine overdoses. Moreover, acute liver failure after multiple dosing of azathioprine was investigated in a patient case study by use of own clinical data. Simulated pharmacokinetic profiles were therefore related to in vivo drug response predicted for genes associated with observed clinical symptoms and to clinical biomarkers measured in vivo. PICD provides a generic platform to investigate drug-induced toxicity at a patient level and thus may facilitate individualized risk assessment during drug development.

Thiopurine monitoring in children with inflammatory bowel disease: a systematic review

AIMS

The aim was to systematically review the evidence on the clinical usefulness of thiopurine metabolite and white blood count (WBC) monitoring in the assessment of clinical outcomes in children with inflammatory bowel disease (IBD).

METHODS

Medline, Embase, Cochrane Central Register of controlled trials and http://www.clinicaltrials.gov were screened in adherence to the PRISMA statement by two independent reviewers for identification of eligible studies. Eligible studies were randomized controlled trials (RCTs), cohort studies and large case series of children with inflammatory bowel disease (IBD) (<18 years) who underwent monitoring of thiopurine metabolites and/or WBC.

RESULTS

Fifteen papers were identified (n = 1026). None of the eligible studies were RCTs. High 6-thioguanine nucleotide (6TGN) concentrations were not consistently associated with leucopenia. Leucopenia was not associated with achievement of clinical remission. A positive but not consistent correlation between 6TGN and clinical remission was reported. Haematological toxicity could not be reliably assessed with 6TGN measurements only. A number of studies supported the use of high 6-methylmercaptopurine ribonucleotides (6MMPR) as an indicator of hepatotoxicity. Low thiopurine metabolite concentration may be indicative of non-compliance.

CONCLUSION

Thiopurine metabolite testing does not safely predict clinical outcome, but may facilitate toxicity surveillance and treatment optimization in poor responders. Current evidence favours the combination of thiopurine metabolite/WBC monitoring and clinic follow-up for prompt identification of haematologic/hepatic toxicity safe dose adjustment, and treatment modification in cases of suboptimal clinical outcome or non-compliance. Well designed RCTs for the identification of robust surrogate markers of thiopurine efficacy and toxicity are required.

Role of oxidative stress mediated by glutathione-s-transferase in thiopurines' toxic effects

Azathioprine (AZA), 6-mercaptopurine (6-MP), and 6-thioguanine (6-TG) are antimetabolite drugs, widely used as immunosuppressants and anticancer agents. Despite their proven efficacy, a high incidence of toxic effects in patients during standard-dose therapy is recorded. The aim of this study is to explain, from a mechanistic point of view, the clinical evidence showing a significant role of glutathione-S-transferase (GST)-M1 genotype on AZA toxicity in inflammatory bowel disease patients. To this aim, the human nontumor IHH and HCEC cell lines were chosen as predictive models of the hepatic and intestinal tissues, respectively. AZA, but not 6-MP and 6-TG, induced a concentration-dependent superoxide anion production that seemed dependent on GSH depletion. N-Acetylcysteine reduced the AZA antiproliferative effect in both cell lines, and GST-M1 overexpression increased both superoxide anion production and cytotoxicity, especially in transfected HCEC cells. In this study, an in vitro model to study thiopurines' metabolism has been set up and helped us to demonstrate, for the first time, a clear role of GST-M1 in modulating AZA cytotoxicity, with a close dependency on superoxide anion production. These results provide the molecular basis to shed light on the clinical evidence suggesting a role of GST-M1 genotype in influencing the toxic effects of AZA treatment.

[Is there any interest to dose the azathioprine's metabolites during inflammatory bowel diseases?]

OBJECTIVE

The objective of our work is to search if there is a relation between azathioprine's metabolites (6-thioguanines nucleotides and 6-methyl mercaptopurines) and clinical efficacy and adverse effects of azathioprine in inflammatory bowel disease population.

METHOD

We included patients with Crohn's disease or ulcerative colitis (UC) treated by azathioprine for a duration more than 1 year. Each patient had a dosage of azathioprine metabolites.

RESULTS

We included 43 Crohn's disease patients and 7 UC. Azathioprine was indicated for steroid dependancy in 23 cases, to prevent post-operative recurrence in 10 cases, to maintain clinical remission obtained by medical treatment in 17 patients. A clinical response to azathioprine (obtention of remission, absence of recurrence during the follow up) was observed in 34 patients.

CONCLUSION

Our work confirms the relation between the doses of azathioprine metabolites and the myelotoxicity due to this molecule.

From model to mechanism: lessons of mice and men in the discovery of protein biologicals for the treatment of inflammatory bowel disease

Successful therapeutics for inflammatory bowel disease (IBD) must be able to reverse effectively the complex processes involved in the manifestation of inflammatory pathology in intact tissues. Although studies of human tissue samples are important to confirm the biological rationale for developing a particular therapeutic, in vivo rodent models of IBD provide a biological 'flask' in which therapeutics can be tested in a more representative setting. Moreover, gene targeting and transgenic technologies in rodents have exponentially increased the repertoire of available IBD models and provided insight into possible contributions that certain genes may have in the pathogenesis of disease. These models have been key in generating the current arsenal of biological therapeutics that are available, or are presently under investigation, for the treatment of IBD patients.

Cost-Effectiveness of Infliximab for the Treatment of Acute Exacerbations of Ulcerative Colitis in the Netherlands

INTRODUCTION

Infliximab is registered for the treatment of moderate-to-severe active ulcerative colitis (UC) adult patients who have had an inadequate response, or are intolerant, or have medical contraindications to therapy including corticosteroids and 5-aminosalicylates or thiopurines (6-mercaptopurine [6-MP] or azathioprine [AZA]). The authors estimate the costs and effects and evaluate the cost-effectiveness of infliximab at the licensed dose of 5 mg/kg versus cyclosporine or surgery for the treatment of adult Dutch patients hospitalized with acute exacerbations of UC, refractory to intravenous steroids.

METHOD

An existing decision analytical model was updated to simulate disease progression of hospitalized UC patients in the Netherlands, refractory to intravenous corticosteroids, and to estimate the costs and benefits associated with infliximab compared to cyclosporine and surgery over a 1-year time horizon. Colectomy rates were derived from infliximab and cyclosporine randomized trials and synthesized using multiple treatment comparison methods. The utility estimates associated with health states of ulcerative colitis patients were obtained from the literature. Resource use and drug use frequencies as well as unit costs were obtained from Dutch sources. The primary effectiveness measure used in the analysis was quality-adjusted life years (QALYs).

RESULTS

For a typical UC patient with body weight of 70 kg, the costs of treatment with infliximab, cyclosporine, and surgery over a 1-year treatment period were €17,062, €14,784, €13,979, respectively. The associated numbers of QALYs were 0.80, 0.70, and 0.58 for infliximab, cyclosporine, and surgery respectively. The incremental cost-effectiveness ratio for infliximab was €24,277 per QALY gained compared to cyclosporine, and €14,639 per QALY gained compared to surgery.

CONCLUSIONS

Infliximab induction regimen appears to be a cost-effective treatment option in comparison to cyclosporine and surgery for hospitalized patients with acute exacerbations of UC, refractory to intravenous corticosteroids in the Netherlands.

Methotrexate in inflammatory bowel disease: a multicenter retrospective study focused on long-term efficacy and safety. The Madrid experience

BACKGROUND

Methotrexate is useful in inflammatory bowel disease (IBD), but its role is secondary because of its limited experience and a supposedly unfavorable safety profile.

AIM

To describe the efficacy and safety of methotrexate in a long-term real clinical practice.

METHODS

Retrospectively reviewed records of IBD patients treated with methotrexate in eight hospitals of Madrid (Spain).

RESULTS

A total of 77 patients were included (80% Crohn's disease); 94% received methotrexate because of steroid dependency. Overall, 82% of the patients initially responded (28% remission). Eighty-eight percent of the patients followed maintenance treatment for a mean of 17 (range: 1-108) months. Forty percent of the patients lost response at a mean of 57 weeks after starting methotrexate. No statistically significant differences were found in the response rates in terms of the disease type, route of administration, or the Montreal Classification category. The mean methotrexate cumulative dose was 1108 mg (range: 25-6480). The main adverse events included 10 cases of gastrointestinal symptoms, four of myelotoxicity, and 10 of abnormal liver function tests, and led to methotrexate withdrawal in four (5%) patients. Transient elastography, performed in 46 patients, detected six additional cases with significant fibrosis and normal liver function tests.

CONCLUSION

Methotrexate is useful in inducing a response in IBD, although its efficacy decreases frequently through the follow-up. Although methotrexate seems safe in the long term, in addition to biochemical controls, a more accurate method to detect liver damage should be considered.

Nutritional therapy versus 6-mercaptopurine as maintenance therapy in patients with Crohn's disease

BACKGROUND

6-Mercaptopurine is often used as maintenance therapy in patients with Crohn's disease. However, toxicities like myelosuppression limit its clinical benefit.

AIMS

To evaluate the efficacy of elemental diet versus 6-mercaptopurine as maintenance therapy in Crohn's disease.

METHODS

Ninety-five eligible patients with Crohn's disease activity index ≤150 were randomly assigned to: 6-mercaptopurine (0.5-1.5mg/kg/day, n=30); Elental as an elemental diet (≥900 kcal/day, n=32); none (control, n=33). In the three groups, patients were and remained on 5-aminosalicylic acid (2250-3000 mg/day). Patients were observed for 2 years and the rate of relapse (Crohn's disease activity index ≥200) was monitored.

RESULTS

At 24 months, the fractions of patients who had maintained remission were 60%, 46.9% and 27.2% for 6-mercaptopurine, Elental and the control groups, respectively. Log-rank test showed better efficacy for 6-mercaptopurine (P=0.0041) and Elental (P=0.0348) versus control. No significant difference was found between 6-mercaptopurine and Elental. Further, in the 6-mercaptopurine group, 2 patients experienced liver injury and one developed alopecia.

CONCLUSIONS

This 24 months comparison study showed that Elental as maintenance therapy in Crohn's disease patients was as effective as 6-mercaptopurine. Elental should be useful for long-term maintenance therapy in Crohn's disease. This is the first comparison study evaluating nutritional therapy versus 6-mercaptopurine.

Thiopurine treatment in inflammatory bowel disease: response predictors, safety, and withdrawal in follow-up

BACKGROUND AND AIMS

Thiopurines represent the mainstay of immunosuppressive therapy in inflammatory bowel diseases. Since it is likely that response to therapy and adverse events depends on the genetic background of patients our study aimed to evaluate retrospectively response to therapy and safety in a mixed IBD population in Southern Europe.

METHODS

We evaluated demographic and clinical data of our patients treated with thiopurines. after 6 months in responders and non-responders to therapy. Moreover the likelihood to remain in thiopurine monotherapy was evaluated in responders, whereas adverse events were investigated in all patients.

RESULTS

Among disease- and patient-related parameters a shorter disease duration, female gender and ileal disease in Crohn's patients were associated with better response. By ROC analysis, the best predictors of response were decreasing values of C-reactive protein and erythrocyte sedimentation rate. In the long-term more than half of IBD patients who responded at 6 months remained on monotherapy at 42 months. Flu-like syndrome represented the most frequent adverse event followed by abnormalities of liver function tests and myelotoxicity. Adverse events did occur at any time and were frequently impredictable.

CONCLUSIONS

In this retrospective study, thiopurines showed a good clinical efficacy, especially in patients with short duration of disease. Normalization of markers of systemic inflammation represents the most useful tool to assess response. Careful monitoring of patients is required during the whole duration of treatment although it may not prevent all severe complications.

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.

Methotrexate in paediatric ulcerative colitis: a retrospective survey at a single tertiary referral centre

BACKGROUND

Patients with ulcerative colitis often receive thiopurines as immunomodulators (IMs) to maintain remission and avoid corticosteroids. If unresponsive or intolerant to these agents, patients are treated with methotrexate, an antimetabolite never assessed in paediatric ulcerative colitis.

AIM

To describe the experience with methotrexate in children with ulcerative colitis.

METHODS

Thirty-two patients (median age 13.9 years) received methotrexate. Pediatric Ulcerative Colitis Activity Index (PUCAI) and use of corticosteroids were the main outcomes evaluated at baseline and at 3, 6 and 12 months.

RESULTS

Indications to methotrexate were azathioprine unresponsiveness in 18 patients, azathioprine intolerance/toxicity in 10 and spondyloarthropathy in four. Response or remission was achieved in 72%, 63% and 50% of patients at 3, 6 and 12 months respectively. Mean PUCAI were 49.5 ± 23.3 at baseline and 32.9 ± 21.9, 29.5 ± 21.8 and 29.4 ± 19.9 at 3, 6 and 12 months respectively (P: 0.03). At the beginning of methotrexate, 16 patients (50%) received corticosteroids that were discontinued in 13 of them (81%) by 6 months. At the end of the study, 11 patients (33%) needed short courses of corticosteroids for disease relapse.

CONCLUSIONS

Methotrexate may be useful in treating children with ulcerative colitis, although large, controlled trials are warranted to define better its effectiveness.

Thiopurine maintenance therapy for ulcerative colitis: the clinical significance of monitoring 6-thioguanine nucleotide

BACKGROUND

6-Mercaptopurine (6-MP) is an effective maintenance medication in patients with ulcerative colitis (UC), but toxic effects like myelosuppression limit its clinical benefit. In the blood, 6-thioguanine (6-TGN) is formed from 6-MP and mediates the therapeutic efficacy and most of the toxicities of 6-MP. The level of 6-TGN depends on the activity of thiopurine methyltransferase (TPMT), inherited as 1 of its 3 polymorphic forms with low, moderate, or normal/high activity. Accordingly, the 6-MP dose needs to be pharmacogenetically guided.

METHODS

Patients with quiescent UC received 6-MP as maintenance therapy and 6-TGN was assayed as its concentrations in red blood cells (RBCs) done by high-performance liquid chromatography. In a preliminary investigation, 30 mg/day 6-MP (n = 50) was given orally over 12 weeks to determine the time course of blood 6-TGN level. Then 257 patients were given 6-MP at 15-80 mg/day in a stepwise manner based on RBC 6-TGN, white blood cell count, and body weight to monitor 6-MP efficacy and safety profiles.

RESULTS

At 30 mg/day 6-MP, RBC 6-TGN peaked over 4-8 weeks. In the main dosing study, the mean RBC 6-TGN level in patients who remained in remission during the 1-year observation time (n = 151) was 322.3 +/- 119.5 pmole/8 x 10(8) RBC versus 204.8 +/- 78.7 pmole/8 x 10(8) RBC in patients (n = 19) who relapsed (P < 0.001). Bone marrow suppression was seen almost exclusively at high 6-TGN concentration ranges. Further, a regression plot showed an inverse relationship between 6-TGN levels in RBC and TPMT enzyme activity.

CONCLUSIONS

By regularly measuring RBC 6-TGN in patients with quiescent UC receiving 6-MP as maintenance therapy, we could monitor bone marrow suppression as well as other toxic side effects. Potentially, this strategy should enable physicians to avoid thiopurine-related adverse effects and identify individuals who may benefit most from 6-MP maintenance therapy.

Thiopurine S-methyltransferase genotype and the use of thiopurines in paediatric inflammatory bowel disease Greek patients

BACKGROUND AND OBJECTIVE

Azathioprine (AZA) and 6-mercaptopurine (6MP) are used in the treatment of paediatric inflammatory bowel disease (IBD). Genetic variations in thiopurine S-methyltranfarase (TPMT) gene have been correlated with enzyme activity and with the occurrence of adverse events to AZA and 6MP. The aim of the present study was to investigate the frequency of the functional TPMT polymorphisms and their association with the occurrence of adverse events during azathioprine therapy in a paediatric IBD cohort.

METHODS

Ninety-seven thiopurine-treated paediatric IBD patients (41.24% boys and 58.76% girls) with a mean age 11.25 years (range 3-16), were assessed for TPMT polymorphisms and adverse events.

RESULTS

Of the 97 patients enrolled in the study, 18 (18.56%) were heterozygous mutated; two (2.06%) were homozygous for a mutated TPMT gene. Ten patients (10.31%) developed adverse effects, and four of them (40%) had one of the variant alleles.

CONCLUSIONS

In this small cohort of subjects, no association was found between TPMT polymorphisms and the occurrence of thiopurines-related adverse events.

Are patients with intermediate TPMT activity at increased risk of myelosuppression when taking thiopurine medications?

Thiopurine S-methyltransferase (TPMT) metabolizes thiopurine medications, including azathioprine and 6-mercaptopurine. Absent TPMT activity (i.e., in individuals homozygous for a variant TPMT allele) is associated with an increased risk of myelosuppression in patients taking thiopurine drugs. However, it is not clear if there is also an increased risk for patients with intermediate TPMT activity (i.e., in individuals heterozygous for a variant TPMT allele).

AIMS

To quantify the increased risk of myelosuppression for patients with intermediate TPMT activity.

MATERIALS & METHODS

A systematic review identified published studies, up to 29 September 2008, that explored the relationship between TMPT and hematological adverse drug reactions to thiopurines. Following a critical appraisal of the quality of published studies, a meta-analysis calculated the odds ratio of myelosuppression for patients with intermediate TPMT activity compared with wild-type.

RESULTS

A total of 67 studies were identified, the majority retrospective cohort in design. Patients with two TPMT variant alleles who are TPMT deficient have a substantial increase in their risk of myelotoxicity (86% of deficient patients developed myelosuppression). The increase in odds ratio of developing leukopenia for patients with intermediate TPMT activity or one TPMT variant allele compared with wild-type was 4.19 (95% CI: 3.20-5.48).

CONCLUSION

This meta-analysis suggests that individuals with both intermediate and absent TPMT activity have an increased risk of developing thiopurine-induced myelosuppression, compared with individuals with normal activity. However, there is significant variability in the quality of the reported studies and large prospective studies to clarify the size of the effect of TPMT variant alleles on the risk of myelosuppression should be conducted. Accurate risk assessments will provide important data to inform clinical guidelines.

[Hepatotoxicity induced by new immunosuppressants]

Immunosuppressants are among the pharmacological agents with the greatest potential to cause adverse reactions, although induction of hepatotoxicity is paradoxical from the pathogenic point of view, since the response of the innate and acquired immune system is a key element in the chain of events leading to chemical liver damage. Hepatotoxicity induced by immunosuppressants is difficult to evaluate since these drugs are sometimes used to treat liver diseases, or in combination with other drugs that can also cause hepatotoxicity, or in the context of liver transplantation, in which rejection or biliary complications can act as confounding factors. In addition, immunosuppressant therapy can favor the development of infections, which by themselves can cause liver damage, or reactivate latent chronic viral hepatitis. Corticosteroids and calcineurin inhibitors only exceptionally cause hepatotoxicity. Methotrexate at high doses and in patients with risk factors can induce advanced fibrosis and cirrhosis. Thiopurine agents can cause a spectrum of hepatic lesions, including hepatocellular of cholestatic lesions, and hepatic vascular alterations. Leflunomide has high hepatotoxic potential, especially when combined with methotrexate. Anti-tumor necrosis factor-alpha agents have rarely been associated with hepatotoxicity, often with detectable autoantibodies, and most of the reactions - some severe - have been linked to infliximab, especially when used in patients with rheumatological diseases.

Management of Crohn's disease in adults

Guidelines for clinical practice are intended to suggest preferable approaches to particular medical problems as established by interpretation and collation of scientifically valid research, derived from extensive review of published literature. When data that will withstand objective scrutiny are not available, a recommendation may be made based on a consensus of experts. Guidelines are intended to apply to the clinical situation for all physicians without regard to specialty. Guidelines are intended to be flexible, not necessarily indicating the only acceptable approach, and should be distinguished from standards of care that are inflexible and rarely violated. Given the wide range of choices in any health-care problem, the physician should select the course best suited to the individual patient and the clinical situation presented. These guidelines are developed under the auspices of the American College of Gastroenterology and its Practice Parameters Committee. Expert opinion is solicited from the outset for the document. The quality of evidence upon which a specific recommendation is based is as follows: Grade A: Homogeneous evidence from multiple well-designed randomized (therapeutic) or cohort (descriptive) controlled trials, each involving a number of participants to be of sufficient statistical power. Grade B: Evidence from at least one large well-designed clinical trial with or without randomization, from cohort or case-control analytic studies, or well-designed meta-analysis. Grade C: Evidence based on clinical experience, descriptive studies, or reports of expert committees. The Committee reviews guidelines in depth, with participation from experienced clinicians and others in related fields. The final recommendations are based on the data available at the time of the production of the document and may be updated with pertinent scientific developments at a later time.

Thiopurine-induced myelotoxicity in patients with inflammatory bowel disease: a review

AIM

Probably, the most important and potentially lethal adverse event of azathioprine (AZA) and mercaptopurine (MP) is myelosuppression. Our aim was to conduct a review of AZA/MP-induced myelotoxicity in inflammatory bowel disease (IBD) patients.

METHODS

Bibliographical searches were performed in MEDLINE/EMBASE. The studies evaluating thiopurine-induced myelotoxicity in patients with IBD were reviewed. The cumulative incidence and the incidence rate of AZA/MP-induced myelotoxicity were calculated by a meta-analysis.

RESULTS

In total, 66 studies (8,302 patients) were included. The cumulative incidence of AZA/MP-induced myelotoxicity was 7% (95% confidence interval [CI] 6-8%). The incidence rate (per patient and year of treatment) of the drug-induced myelotoxicity was 3% (95% CI 3-4%). The risk was roughly similar with AZA and with MP (7%vs 9%). The duration of AZA/MP treatment in patients with myelotoxicity ranged from 12 days to 27 yr. The cumulative incidence of infections among AZA/MP-induced myelotoxicity patients was 6.5%. The cumulative incidence of severe myelotoxicity was 1.1% (incidence rate 0.9%). Three deaths were reported due to myelotoxicity (cumulative incidence 0.06%, 95% CI 0.02-0.17%). The risk of death among patients who developed myelotoxicity was 0.94% (95% CI 0.32-2.70%).

CONCLUSION

The incidence rate of myelotoxicity in IBD patients receiving AZA/MP is approximately 3% per patient and year of treatment. Although bone marrow toxicity may develop at any time after starting the therapy, this happens more frequently during the first months. The incidence rate of severe myelotoxicity is less than 1% per patient and year of treatment, and the mortality risk is less than 0.1% (which means that the risk of death among IBD patients who develop myelotoxicity is approximately 1%).

Inflammatory bowel diseases in the elderly

Inflammatory bowel disease (IBD) in elderly individuals is associated with a unique set of challenges, some of which are related to age. This article examines the diagnosis and management of IBD in the context of recent advances in the understanding of its pathogenesis, and newer therapeutic modalities that have been possible from these advances.

Prophylaxis against Pneumocystis pneumonia in patients with inflammatory bowel disease: toward a standard of care

Patients with Crohn's Disease and ulcerative colitis are increasingly treated with a host of immunomodulatory and immunosuppressive medications, including thiopurines and antibody-based biologic agents. Despite the known infectious complications associated with these therapies from the HIV and solid organ transplant literature, there are currently no well-defined concise guidelines to assist gastroenterologists and other physicians in the utility and indication for prophylaxis against Pneumocystis pneumonia and other infections in inflammatory bowel disease (IBD) patients. In this article, we discuss the evidence of various infections associated with immunocompromise in HIV/AIDS, organ transplantation, and in other immunocompromised states, and discuss the evidence for the efficacy and safety of various infectious prophylaxis protocols. In addition, we discuss the evidence for Pneumocystis and other infections in IBD patients treated with corticosteroids, azathioprine/6-MP, biologic agents and other therapies, and we present the case for various antibiotic (and antiviral) regimens to prevent such infections. Based on the review of the literature, this discussion represents a true call for guidelines for infection prophylaxis, to help guide gastroenterologists and all practitioners who care for the challenging population of IBD patients.

Role of methotrexate in the management of Crohn disease

BACKGROUND

The majority of children with Crohn disease (CD) are likely to need some form of immunomodulatory therapy to maintain remission and to avoid long-term corticosteroid usage. Although thiopurine agents are commonly used, some children are unresponsive or intolerant to these drugs. Biological agents like infliximab are being increasingly used in these circumstances, but long-term safety has yet to be established. Methotrexate has been shown to induce and maintain remission in CD in many adult studies, but pediatric data are limited. The present report describes our experience of using methotrexate in CD in children.

PATIENTS AND METHODS

All children with CD treated with methotrexate were identified by the departmental database. Case records were reviewed for site of disease, Pediatric Crohn Disease Activity Index, medications, time to achieve remission, duration of remission, and complications.

RESULTS

A total of 10 children received methotrexate, 7 of whom were female and 3 of whom were male. All of the children had colonic involvement and had active disease despite previous standard medical treatments. Seven children exhibited remission with methotrexate treatment. Median time to achieve remission was 12 weeks and median duration of remission was 21 months to the point of assessment. One child had transient increase of alanine aminotransferase levels and another developed neutropenia, which remitted with dose reduction. None needed discontinuation of methotrexate treatment.

CONCLUSIONS

Methotrexate is effective and well tolerated in children with CD. It should be considered in those patients who do not experience a remission with standard medications because it may avoid the use of biological agents and their potential uncertain long-term side effects.

[Monitoring of thiopurine methyltransferase and thiopurine metabolites to optimize azathioprine therapy in inflammatory bowel disease]

Determination of the activity of thiopurine methyltransferase (TPMT) and of thiopurine metabolites (6-thioguanine and 6-methylmercaptopurine nucleotides) could be useful for individualized monitoring of azathioprine (AZA) and 6-mercaptopurine (6-MP) doses. TPMT activity in the general population follows a trimodal distribution, in which approximately 0.3% of the population is homozygotic for the low-activity allele. A notable correlation has been observed between the low TPMP activity genotype or phenotype and the risk of myelotoxicity. Patients with a high TPMT activity genotype or homozygous phenotype should receive immunosuppressive doses that have clearly been demonstrated to be effective. In contrast, in patients with a low TPMT activity genotype or homozygous phenotype, the use of AZA/6-MP should be contraindicated or only very small doses should be administered. Importantly, TPMP deficiency explains only some cases of myelotoxicity and consequently periodic laboratory testing should be performed in patients receiving AZA/6-MP, even though TPMP function may be normal. Currently, the utility of routine thiopurine metabolite determinations in patients undergoing AZA/6-MP therapy has not been established and this practice should be limited to specific situations such as lack of response to thiopurine therapy or the occurrence of thiopurine-related adverse effects. Randomized trials comparing the routine strategy of AZA/6-MP dosing (based exclusively on the patient's weight) versus individualized monitoring (based on quantification of TPMP activity and/or thiopurine metabolites) are required before definitive conclusions on the most effective alternative can be drawn.

Long-term results with azathioprine therapy in patients with corticosteroid-dependent Crohn's disease: open-label prospective study

BACKGROUND

A substantial number of patients with Crohn's disease (CD) become dependent on steroids after induction therapy. Treatment with azathioprine (AZA) may be beneficial in such patients. The present open-label study evaluated the long-term safety and efficacy of AZA in steroid-dependent CD patients.

METHODS

Adult patients with steroid-dependent CD were enrolled for AZA therapy over a 7-year period. The average dose of AZA was 2.0-3.0 mg/kg per day, adjusted according to clinical response and occurrence of adverse effects. Steroid therapy was tapered off according to a predefined schedule. Long-term outcome and adverse reactions were evaluated.

RESULTS

Sixty-nine patients were prospectively included. Steroid-free remission was achieved in 68-81% of patients, partial response in 14.5-27.3% and failure to respond to AZA in 4-15.9% over the initial 48 months. However, the rate of wean from steroid therapy decreased to 53-60% while the rate of failure increased from 6.7% to 17.6% after this period. A breakthrough of symptoms during continuous AZA therapy was common, particularly after 48 months on AZA. The mean leukocyte count at the end of 12 months of therapy was significantly lower in patients who achieved complete response on AZA than in the non-responders (5197 +/- 1250 cells/mm(3) vs 8340 +/- 1310 cells/mm(3), respectively; P < 0.01). Azathioprine was relatively well-tolerated and the incidence of serious adverse effects was small.

CONCLUSIONS

Azathioprine was relatively safe and moderately effective for long-term maintenance of steroid-free clinical remission in corticosteroid-dependent CD patients. Patients were more successfully weaned from prednisone treatment, and clinical remission was more often maintained during the first 48 months of AZA therapy. A significant decrease in the white blood cell count at the end of 12 months on AZA was the single factor associated with weaning from steroid dependence.

Glutathione-S-transferase genotypes and the adverse effects of azathioprine in young patients with inflammatory bowel disease

BACKGROUND

Adverse drug reactions to azathioprine, the prodrug of 6-mercaptopurine, occur in 15%-38% of patients and the majority are not explained by thiopurine-S-methyltransferase (TPMT) deficiency. Azathioprine is known to induce glutathione depletion and consumption of glutathione is greater in cells with high glutathione-S-transferase (GST) activity compared with those with low activity; moreover, some reports indicate that GST might play a direct role in the reaction of glutathione with azathioprine. The association between polymorphisms of GST-M1, GST-P1, GST-T1, and TPMT genes and the adverse effects of azathioprine was therefore investigated.

METHODS

Seventy patients with inflammatory bowel disease (IBD), treated with azathioprine, were enrolled and clinical data were retrospectively determined. TPMT and GST genotyping were performed by polymerase chain reaction (PCR) assays on DNA extracted from blood samples.

RESULTS

Fifteen patients developed adverse effects (21.4%); there was a significant underrepresentation of the GST-M1 null genotype among patients developing adverse drug reactions to azathioprine (odds ratio [OR] = 0.18, 95% confidence interval [CI] = 0.037-0.72, P = 0.0072) compared with patients who did not develop adverse effects. Patients heterozygous for TPMT mutations presented a marginally significant increased probability of developing adverse effects (OR = 6.38, 95% CI = 0.66-84.1, P = 0.062). Moreover, among the 55 patients who did not develop adverse effects, there was a significant underrepresentation of the GST-M1 null genotype among patients who displayed lymphopenia as compared with those that did not display this effect of azathioprine (OR = 0.15, 95% CI = 0.013-1.08, P = 0.032).

CONCLUSION

Patients with IBD with a wildtype GST-M1 genotype present increased probability of developing adverse effects and increased incidence of lymphopenia during azathioprine treatment.

Thiopurine methyltransferase (TPMT) activity and adverse effects of azathioprine in inflammatory bowel disease: long-term follow-up study of 394 patients

AIM

To prospectively evaluate whether a relationship between thiopurine methyltransferase (TPMT) activity and incidence of adverse effects (especially myelotoxicity) exists, in a long-term follow-up study of a large group of patients with inflammatory bowel disease treated with azathioprine.

METHODS

TPMT activity in red blood cells (RBC) was measured by a radiochemical method in 394 consecutive patients with Crohn's disease (238) or ulcerative colitis (156) starting treatment with azathioprine. The relationship among several variables and TPMT values was assessed, and the correlation between such levels and the incidence of adverse effects was evaluated.

RESULTS

Mean TPMT value was 18.6 +/- 4 U/mL RBCs (range 9.4-33.7). No patient had low levels (<5), 7.1% had intermediate levels (5-13.7), and 92.9% had high levels (>13.8). Differences (P < 0.001) were demonstrated in TPMT activity depending on the type of inflammatory bowel disease, but not on the remaining variables (including treatment with 5-aminosalycilates). Adverse effects were reported in 74 patients (18.8%), the most frequent being gastrointestinal intolerance (9.1%) and myelotoxicity (4.3%). No patient having adverse effects had low TPMT levels. However, mean TPMT activity was lower in those with adverse effects (16.6 +/- 3 vs 19.1 +/- 4 U/mL, P < 0.001). Moreover, the probability of suffering myelotoxicity in the high TPMT group was only 3.5%, compared with 14.3% in the TPMT intermediate group (95% CI = 1.37-14.9; OR = 4.5).

CONCLUSIONS

The strategy of determining TPMT activity in all patients prior to initiating treatment with azathioprine could help to minimize the risk of myelotoxicity, as patients with intermediate TPMT activity had fourfold more risk than high TPMT activity patients.

Evolution of thiopurine use in pediatric inflammatory bowel disease in an academic center

OBJECTIVES

We evaluated how our use of thiopurines was altered by determination of thiopurine methyltransferase (TPMT) level and drug dose adjustment guided by a 6-mercaptopurine metabolite assay. We further examined whether these resulted in better selection of the drug dose, improved control of disease, and decreased corticosteroid use in pediatric inflammatory bowel disease (IBD).

PATIENTS AND METHODS

This is a retrospective review of 101 pediatric patients with IBD receiving a stable dose of azathioprine (AZA) for 4 months or longer. The study group (n = 64) consisted of patients who received AZA and had metabolite levels measured. The comparison group (n = 37) consisted of patients who were receiving AZA before the availability of metabolite measurement. The TPMT level was measured in study group patients before starting AZA.

RESULTS

Patients with normal TPMT level received a higher starting dose of AZA than in patients who were heterozygous for TPMT deficiency (1.7 vs 0.9 mg/[kg x d], P < 0.0001). Study group patients received a higher starting dose (1.6 vs 1.2 mg/[kg x d], P = 0.001) and a higher final dose of AZA (2.4 vs 1.7 mg/[kg x d], P < 0.0001) compared with patients in the comparison group. These patients also had more dose adjustments (0.8 vs 0.4 mg/kg, P < 0.002). The number of disease exacerbations per patient per year was 55% less in the study group (95% CI, 17%-76%, P < 0.0001). The study group patients received less prednisone (P < 0.0001) and had lower disease activity scores (P < 0.05). There was no difference between groups in infliximab use or surgery rate.

CONCLUSIONS

Azathioprine dose adjustment using a 6-mercaptopurine metabolite assay was associated with use of higher doses, improved control of disease and decreased corticosteroid use in pediatric patients with IBD.

Advances in therapeutic approaches to ulcerative colitis and Crohn's disease

Advances (from 2004 to 2006) in the use of conventional agents include the molecular mechanisms of action, which have implications for monitoring (azathioprine and thioguanosine triphosphate) and chemoprevention (mesalamine and peroxisome proliferator activated receptor gamma). Advances in biotherapy include new data on monoclonal antibodies (infliximab in ulcerative colitis, adalimumab, certolizumab pegol, fontolizumab, selective anti-adhesion molecules, and others), antisense oligonucleotides, the development of small molecules, and cell-gene therapy (including helminth ova, leukocytapheresis, stem cell transplantation, and probiotic intestinal mucosal delivery systems). However, management of inflammatory bowel disease is about more than drug therapy, dose, and timing. The goals remain induction of remission, limitation of side effects, modification of the pattern of disease, and avoidance of complications. With the cost and complexity of biotherapy, inflammatory bowel disease is emerging as a specific subspecialty.

Cyclosporine for severe ulcerative colitis

OBJECTIVE

To evaluate evidence for the use of cyclosporine in treating patients with severe ulcerative colitis.

DATA SOURCES

A literature search was performed using MEDLINE, EMBASE, Cochrane Database, and ISI Web of Knowledge (1966-November 2005) with the search terms cyclosporine, cyclosporin A, CsA, ulcerative colitis, UC, inflammatory bowel disease, IBD, steroid-refractory, and immunosuppression. Additional papers were located by hand-searching relevant references. Only human studies in adults and literature published in English were included.

DATA SYNTHESIS

Intravenous cyclosporine has been evaluated for the treatment of severe ulcerative colitis in 4 randomized, controlled trials, as well as in many open-label and retrospective studies. Studies that evaluated cyclosporine for severe ulcerative colitis were reviewed. All 4 controlled trials showed an initial positive clinical response as defined by the Crohn's Activity Index when intravenous cyclosporine 4 mg/kg/day was administered as monotherapy or combined with intravenous corticosteroids. One of the 4 trials indicated that high-dose cyclosporine (4 mg/kg/day) has no additional clinical benefit over the low-dose (2 mg/kg/day) and that the lower dose may improve safety related to dose-dependent adverse effects.

CONCLUSIONS

There is evidence to support the use of intravenous cyclosporine for patients with severe ulcerative colitis who are refractory to corticosteroid therapy. Because most of the adverse effects associated with cyclosporine are dose dependent, therapy should be initiated with the lower 2 mg/kg/day dose. Subsequent doses should be adjusted based on cyclosporine blood concentrations of 150-250 ng/mL. Cyclosporine should be used only to induce remission and serve as a "bridge" to azathioprine or 6-mercaptopurine maintenance therapy. At this time, there are insufficient data to support the long-term use of cyclosporine monotherapy for avoidance of surgery or maintenance of remission.

TPMT genotype and the use of thiopurines in paediatric inflammatory bowel disease

BACKGROUND

Thiopurines are used in the treatment of inflammatory bowel disease. They are metabolised via methylation by thiopurine-S-methyltransferase (TPMT), which displays a genetically determined polymorphic activity. Subjects with reduced TPMT activity have a higher concentration of active thiopurine metabolites and may be at increased risk of bone-marrow suppression.

AIMS

To evaluate the relevance of TPMT genotyping in the management of thiopurines therapy in inflammatory bowel disease patients.

PATIENTS AND METHODS

Adverse effects and clinical response were determined retrospectively and correlated with TPMT genotype in 70 paediatric inflammatory bowel disease patients.

RESULTS

Nineteen patients (27.1%) developed adverse effects; of the 51 who did not, 34 (66.7%) responded to treatment. Five patients (7.1%) were heterozygous for a variant TPMT allele; two of these (40%) were intolerant to thiopurines, compared to 17 of the 65 patients (26.2%) with a wild type gene (O.R. 1.88, 95% CI 0.29-12.2, p=0.61); among the 34 responders, the median dosage of the drug required to obtain remission was lower for mutated than for wild type patients (1.6mgkg(-1)day(-1) versus 2.0mgkg(-1)day(-1), p=0.043).

CONCLUSIONS

There was no significant association between adverse effects of thiopurines and TPMT heterozygous genotype, but TPMT genotyping could be useful in establishing the most appropriate dose of thiopurines to start treatment.