Azathioprine and 6-mercaptopurine for maintenance of remission in ulcerative colitis

Explore the underlying oral efficacy of α-, β-, γ-Cyclodextrin against the ulcerative colitis using in vitro and in vivo studies assisted by network pharmacology

The incidence of ulcerative colitis (UC) is rising worldwide. As a refractory and recurrent disease, UC could seriously affect the patients' quality of life. However, current clinical medical treatments for UC are accompanied by various side effects, especially for long-term applications. Here, the underlying efficacy of cyclodextrins (CDs) was studied. As common excipients, CDs endow proven safety for long-term applications. Results of predictive methods derived from network pharmacology prompted the potential anti-inflammatory effects of CDs by oral administration. RAW264.7 cell experiments verified that CDs could inhibit the excessive secretion of TNF-α (β-CD > α-CD ≈ γ-CD), IL-6, and NO (α-CD > β-CD ≈ γ-CD) as predicted. In mice with DSS-induced acute UC, oral administration of CDs could effectively mitigate the pathological damage of colon tissue and reduce the level of inflammatory mediators. Moreover, 16S rRNA sequencing displayed that gut microbes disturbed by DSS were significantly regulated by CDs. Conclusively, the study showed the therapeutic application prospects of CDs in UC treatment and indicated the feasibility and advantages of developing 'new' therapeutic activities of 'old' ingredients.Communicated by Ramaswamy H. Sarma.

Azathioprine promotes intestinal epithelial cell differentiation into Paneth cells and alleviates ileal Crohn's disease severity

Paneth cells (PCs), a subset of intestinal epithelial cells (IECs) found at the base of small intestinal crypts, play an essential role in maintaining intestinal homeostasis. Altered PCs function is associated with diverse intestinal pathologies, including ileal Crohn's disease (CD). CD patients with ileal involvement have been previously demonstrated to display impairment in PCs and decreased levels of anti-microbial peptides. Although the immunosuppressive drug Azathioprine (AZA) is widely used in CD therapy, the impact of AZA on IEC differentiation remains largely elusive. In the present study, we hypothesized that the orally administered drug AZA also exerts its effect through modulation of the intestinal epithelium and specifically via modulation of PC function. AZA-treated CD patients exhibited an ileal upregulation of AMPs on both mRNA and protein levels compared to non-AZA treated patients. Upon in vitro AZA stimulation, intestinal epithelial cell line MODE-K exhibited heightened expression levels of PC marker in concert with diminished cell proliferation but boosted mitochondrial OXPHOS activity. Moreover, differentiation of IECs, including PCs differentiation, was boosted in AZA-treated murine small intestinal organoids and was associated with decreased D-glucose consumption and decreased growth rates. Of note, AZA treatment strongly decreased Lgr5 mRNA expression as well as Ki67 positive cells. Further, AZA restored dysregulated PCs associated with mitochondrial dysfunction. AZA-dependent inhibition of IEC proliferation is accompanied by boosted mitochondria function and IEC differentiation into PC.

A rare case report: Myopathy related to the interaction between azathioprine and infliximab in the treatment of ulcerative colitis and ankylosing spondylitis

Key Clinical Message

Administering azathioprine or infliximab for UC and AS treatment carries a significant risk of adverse reactions. Here, we present the case diagnosed with UC and AS, who received treatment with azathioprine and infliximab for 10 months, and subsequently developed drug-induced myopathy affecting the right vastus medialis muscle.

Abstract

Drug-induced myopathy is an uncommon form of muscle injury that can arise in patients without preexisting muscle conditions when exposed to therapeutic doses of certain medications. Administering azathioprine or infliximab for ulcerative colitis (UC) and ankylosing spondylitis (AS) treatment carries a significant risk of adverse reactions, including drug-induced myopathy and increased susceptibility to opportunistic infections. However, occurrences of myopathy induced by the combination of azathioprine and infliximab are rarely reported in clinical practice. Here, we present the case of a 37-year-old male patient diagnosed with UC and AS, who received treatment with azathioprine and infliximab for 10 months. Despite the resolution of symptoms and improvement in intestinal mucosal inflammation observed via endoscopy, the patient subsequently developed drug-induced myopathy affecting the right vastus medialis muscle.

Selecting first-line advanced therapy for ulcerative colitis: A clinical application of personalized medicine

Ulcerative colitis (UC) is a chronic autoimmune inflammatory disease that affects the colon, leading to symptoms of bloody diarrhea, abdominal cramps, and urgency. The treatment of UC has evolved over the past few decades from locally active anti-inflammatory compounds to more selective therapies that target specific arrays of the immune system. The challenge of selecting the first advanced therapy became apparent in this rapidly expanding landscape of medications. No current investigational tools, such as genetic, immunologic, or biological markers, can guide the identification of the safest and most effective therapeutic option for each patient. Hence, physicians must carefully assess patient/disease characteristics and match them with the most suitable drug through a clinically driven assessment. In this paper, we outline patient and drug characteristics that play a role in selecting first-line advanced therapies for UC and propose an algorithm for selection.

Uphill battle: Innovation of thiopurine therapy in global inflammatory bowel disease care

Inflammatory bowel disease (IBD) is a chronic inflammatory disorder of the gastrointestinal tract that encompasses two major conditions: Crohn's disease (CD) and ulcerative colitis (UC). Historically, IBD has been primarily reported in western countries, but over the past decades, its prevalence is rapidly increasing, especially in lower and middle-income countries (LMICs) such as India and China and also in Sub-Saharan Africa. The prevalence of IBD in LMICs has been the subject of growing concern due to the impact of access to public healthcare and the burden it places on healthcare resources. The classical thiopurines face significant challenges due to cessation of therapy in approximately half of patients within one year due to side effects or ineffectiveness. In this article, we highlight innovating thiopurine treatment for IBD patients in downregulating side effects and improving efficacy.

White Blood Cell Counts and Future Relapse in Ulcerative Colitis under Low-Dose Thiopurine Treatment in Real-World Practice: A 3-Year Japanese Multi-Center Retrospective Cohort Study

Introduction

Whether white blood cell (WBC) counts are predictors for the effectiveness of thiopurine treatment in ulcerative colitis (UC) has been inconclusive in previous studies with small sample sizes. We investigated the association between WBC counts and future relapses in UC patients in a large-scale multi-center study.

Methods

This retrospective cohort study enrolled a total of 723 UC patients in remission from 33 hospitals and followed up for 3 years. Relapse was defined as a need for treatment intensification. The risk of relapse was compared among patients with the baseline WBC counts <3,000/µL (N = 31), 3,000-4,000/µL (N = 167), 4,000-5,000/µL (N = 241), and ≥5,000/µL (N = 284) using a Cox regression model analysis. Moreover, exploratory analyses were conducted to identify other factors predicting relapse.

Results

During a median follow-up period of 1,095 (interquartile range, 1,032-1,119) days, relapse occurred in 17.2% (125/723). In a crude analysis, WBC counts were not associated with relapse; hazard ratios (HRs) (95% confidence interval [CI]) were 1.50 (0.74-3.06), 1.02 (0.66-1.59), and 0.67 (0.43-1.05) in WBC <3,000/µL, 3,000-4,000/µL, and 4,000-5,000/µL groups, respectively (WBC ≥5,000/µL group, as reference). Multivariable-adjusted analyses showed similar results; HRs (95% CI) were 1.21 (0.59-2.49), 1.08 (0.69-1.69), and 0.69 (0.44-1.07), in <3,000/µL, 3,000-4,000/µL, and 4,000-5,000/µL groups, respectively. In the exploratory analyses, thiopurine use <1 year and a mean corpuscular volume <90 fL were predictors for relapse.

Discussion/Conclusion

WBC counts were not predictors for future relapses in patients with UC treated with thiopurine as a maintenance therapy.

What Happens to Patients with Inflammatory Bowel Disease Who Are Intolerant to Thiopurines?

Introduction

The clinical consequences for patients with inflammatory bowel disease (IBD) who stop treatment owing to side effects have not been fully investigated.

Methods

This retrospective observational study aimed to compare patients who discontinued thiopurine treatment due to side effects with those who tolerated thiopurine treatment in the use of other IBD drugs, surgery, and fecal calprotectin values in the first 5 years after the start of thiopurine treatment.

Results

The proportion of patients with IBD who initiated thiopurine treatment at our clinic was 44% (32% ulcerative colitis and 64% Crohn's disease) and 31% (n = 94) of those patients had to stop thiopurine treatment within 5 years due to side effects. Patients who discontinued thiopurine treatment due to intolerance were significantly older (median age 33 vs. 27 years, p = 0.003), significantly more often used prednisolone (89 vs. 76%, p = 0.009), and used to a lesser extent TNF inhibitors at the start of thiopurine treatment (3% vs. 9%, p = 0.062). Budesonide treatment and non-TNF inhibitor second-line therapy were significantly more commonly used in patients who discontinued thiopurine treatment owing to side effects, but there were no statistically significant differences in the use of other treatments. The proportion of patients with a median FC >200 μg/g was significantly higher during follow-up in patients with UC who discontinued thiopurine treatment owing to side effects.

Conclusions

Patients who discontinued thiopurines owing to side effects were prescribed more budesonide and non-TNF inhibitor second-line therapy, but there were no differences in the use of TNF inhibitors, prednisolone, or surgery.

Pharmacomicrobiomics of cell-cycle specific anti-cancer drugs - is it a new perspective for personalized treatment of cancer patients?

Intestinal bacteria are equipped with an enzyme apparatus that is involved in the active biotransformation of xenobiotics, including drugs. Pharmacomicrobiomics, a new area of pharmacology, analyses interactions between bacteria and xenobiotics. However, there is another side to the coin. Pharmacotherapeutic agents can significantly modify the microbiota, which consequently affects their efficacy. In this review, we comprehensively gathered scientific evidence on the interplay between anticancer therapies and gut microbes. We also underlined how such interactions might impact the host response to a given therapy. We discuss the possibility of modulating the gut microbiota to increase the effectiveness/decrease the incidence of adverse events during tumor therapy. The anticipation of the future brings new evidence that gut microbiota is a target of interest to increase the efficacy of therapy.

Comparing Myelosuppression Frequency in Indian Inflammatory Bowel Disease Patients: A Randomized Trial of Full Dose Versus Gradual Escalation of Thiopurines

INTRODUCTION

We aimed to compare the frequency of myelosuppression in patients initiating azathioprine (AZA) at full dose versus those undergoing gradual dose escalation.

METHODS

Forty patients with inflammatory bowel disease were recruited over one year and randomized into two groups of 20. Group A initiated AZA at a full dose of 2 mg/kg, while group B started at 1 mg/kg with subsequent dose increases at regular intervals.

RESULTS

Seventeen patients from each group were included in the final analysis. During follow-up, two patients (11.8%) from group A and four patients (23.5%) from group B experienced relapses (p=0.65). Myelosuppression occurred in two patients (11.8%) from each group. Absolute neutrophil counts in group A tended to have lower median values than those in group B, particularly four weeks after AZA initiation. Univariate analysis identified serum proteins, albumin, and bilirubin as significantly associated with leukopenia, but these factors were not significant according to multivariate analysis.

CONCLUSIONS

The incidence of myelosuppression was similar between the groups. Patients with full-dose initiation of AZA had numerically fewer relapses during the follow-up period.

Responsive nanosystems for targeted therapy of ulcerative colitis: Current practices and future perspectives

The pharmacological approach to treating gastrointestinal diseases is suffering from various challenges. Among such gastrointestinal diseases, ulcerative colitis manifests inflammation at the colon site specifically. Patients suffering from ulcerative colitis notably exhibit thin mucus layers that offer increased permeability for the attacking pathogens. In the majority of ulcerative colitis patients, the conventional treatment options fail in controlling the symptoms of the disease leading to distressing effects on the quality of life. Such a scenario is due to the failure of conventional therapies to target the loaded moiety into specific diseased sites in the colon. Targeted carriers are needed to address this issue and enhance the drug effects. Conventional nanocarriers are mostly readily cleared and have nonspecific targeting. To accumulate the desired concentration of the therapeutic candidates at the inflamed area of the colon, smart nanomaterials with responsive nature have been explored recently that include pH responsive, reactive oxygen species responsive (ROS), enzyme responsive and thermo - responsive smart nanocarrier systems. The formulation of such responsive smart nanocarriers from nanotechnology scaffolds has resulted in the selective release of therapeutic drugs, avoiding systemic absorption and limiting the undesired delivery of targeting drugs into healthy tissues. Recent advancements in the field of responsive nanocarrier systems have resulted in the fabrication of multi-responsive systems i.e. dual responsive nanocarriers and derivitization that has increased the biological tissues and smart nanocarrier's interaction. In addition, it has also led to efficient targeting and significant cellular uptake of the therapeutic moieties. Herein, we have highlighted the latest status of the responsive nanocarrier drug delivery system, its applications for on-demand delivery of drug candidates for ulcerative colitis, and the prospects are underpinned.

Risk factors for drug-related acute pancreatitis: an analysis of the FDA adverse event reporting system (FAERS)

Objective: While several drugs have been linked to acute pancreatitis (AP), the AP-related risk of most drugs remains unclear. This study investigated the risk factors for drug-induced AP by analyzing a large dataset from the FDA Adverse Event Reporting System (FAERS). Methods: The reporting odds ratios (ROR) were used to assess the reports of drug-induced AP from the first quarter of 2004 to the second quarter of 2022. Single-factor, LASSO, and multi-factor regression analysis were performed to explore drug-related AP-related risk factors. Bonferroni correction was applied for the multiple comparisons performed. Results: A total of 264 drugs associated with AP, including antineoplastic drugs (35/264), antidiabetic drugs (28/264), antibacterial drugs (24/264), immunomodulatory drugs (11/264), antipsychotic drugs (6/264), and other drugs (160/264) were retrieved. Multi-factor analysis showed that males, age 41-54 years old, and 36 drugs, including Tigecycline, were risk factors for drug-related AP. The median time to drug-related AP onset was 31 days (interquartile range [IQR] 7-102 days) and about 75% of adverse events occurred within 100 days. Conclusion: These findings may help clinicians to identify drug-related AP at the early stage and can be used to inform future studies of drug-related AP pathogenesis.

Discovery and Optimization of Novel hDHODH Inhibitors for the Treatment of Inflammatory Bowel Disease

As a key rate-limiting enzyme in the de novo synthesis of pyrimidine nucleotides, human dihydroorotate dehydrogenase (hDHODH) is considered a known target for the treatment of autoimmune diseases, including inflammatory bowel disease (IBD). Herein, BAY 41-2272 with a 1H-pyrazolo[3,4-b]pyridine scaffold was identified as an hDHODH inhibitor by screening an active compound library containing 5091 molecules. Further optimization led to 2-(1-(2-chloro-6-fluorobenzyl)-1H-pyrrolo[2,3-b]pyridin-3-yl)-5-cyclopropylpyrimidin-4-amine (w2), which was found to be the most promising and drug-like compound with potent inhibitory activity against hDHODH (IC50 = 173.4 nM). Compound w2 demonstrated acceptable pharmacokinetic characteristics and alleviated the severity of acute ulcerative colitis induced by dextran sulfate sodium in a dose-dependent manner. Notably, w2 exerted better therapeutic effects on ulcerative colitis than hDHODH inhibitor vidofludimus and Janus kinase (JAK) inhibitor tofacitinib. Taken together, w2 is a promising hDHODH inhibitor for the treatment of IBD and deserves to be developed as a preclinical candidate.

Successful treatment of ulcerative colitis with anakinra: a case report

Currently the effect of IL-1 blockade on ulcerative colitis (UC) is still ambiguous. This case report describes a patient with UC who developed severe complications after an episode of azathioprineinduced pancytopenia including cytomegalovirus pneumonitis, hemophagocytic lymphohistiocytosis, and probable pulmonary aspergillosis. Imaging after the hospitalization revealed a severe disseminated chronic candidiasis and persisting inflammation was seen. Genetic testing revealed heterozygous variants in NOD2 and NLRP12, and cytokine testing showed an increase in IL-1Ra, IL-18, CXCL9, and CXCL10. Consequently an IL-1 mediated autoinflammatory syndrome was suspected. Simultaneously, the patient developed a corticosteroid dependent UC flare-up. Treatment with anakinra was initiated for the IL-1 mediated disease which quickly induced remission of both the inflammatory syndrome and the UC.

Ulcerative Colitis in Adults: A Review

Importance

Ulcerative colitis (UC) is a chronic inflammatory condition of the colon, with a prevalence exceeding 400 per 100 000 in North America. Individuals with UC have a lower life expectancy and are at increased risk for colectomy and colorectal cancer.

Observations

UC impairs quality of life secondary to inflammation of the colon causing chronic diarrhea and rectal bleeding. Extraintestinal manifestations, such as primary sclerosing cholangitis, occur in approximately 27% of patients with UC. People with UC require monitoring of symptoms and biomarkers of inflammation (eg, fecal calprotectin), and require colonoscopy at 8 years from diagnosis for surveillance of dysplasia. Risk stratification by disease location (eg, Montreal Classification) and disease activity (eg, Mayo Score) can guide management of UC. First-line therapy for induction and maintenance of remission of mild to moderate UC is 5-aminosalicylic acid. Moderate to severe UC may require oral corticosteroids for induction of remission as a bridge to medications that sustain remission (biologic monoclonal antibodies against tumor necrosis factor [eg, infliximab], α4β7 integrins [vedolizumab], and interleukin [IL] 12 and IL-23 [ustekinumab]) and oral small molecules that inhibit janus kinase (eg, tofacitinib) or modulate sphingosine-1-phosphate (ozanimod). Despite advances in medical therapies, the highest response to these treatments ranges from 30% to 60% in clinical trials. Within 5 years of diagnosis, approximately 20% of patients with UC are hospitalized and approximately 7% undergo colectomy. The risk of colorectal cancer after 20 years of disease duration is 4.5%, and people with UC have a 1.7-fold higher risk for colorectal cancer compared with the general population. Life expectancy in people with UC is approximately 80.5 years for females and 76.7 years for males, which is approximately 5 years shorter than people without UC.

Conclusions and Relevance

UC affects approximately 400 of every 100 000 people in North America. An effective treatment for mild to moderate UC is 5-aminosalicylic acid, whereas moderate to severe UC can be treated with advanced therapies that target specific inflammation pathways, including monoclonal antibodies to tumor necrosis factor, α4β7 integrins, and IL-12 and IL-23 cytokines, as well as oral small molecule therapies targeting janus kinase or sphingosine-1-phosphate.

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.

Ulcerative colitis (K51), adults

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GADECCU 2022 Guideline for the treatment of Ulcerative Colitis. Adaptation and updating of the GETECCU 2020 Guideline

INTRODUCTION

Ulcerative colitis (UC) is a chronic inflammatory disease that compromises the colon, affecting the quality of life of individuals of any age. In practice, there is a wide spectrum of clinical situations. The advances made in the physio pathogenesis of UC have allowed the development of new, more effective and safer therapeutic agents.

OBJECTIVES

To update and expand the evaluation of the efficacy and safety of relevant treatments for remission induction and maintenance after a mild, moderate or severe flare of UC.

RECIPIENTS

Gastroenterologists, coloproctologists, general practitioners, family physicians and others health professionals, interested in the treatment of UC.

METHODOLOGY

GADECCU authorities obtained authorization from GETECCU to adapt and update the GETECCU 2020 Guide for the treatment of UC. Prepared with GRADE methodology. A team was formed that included authors, a panel of experts, a nurse and a patient, methodological experts, and external reviewers. GRADE methodology was used with the new information.

RESULTS

A 118-page document was prepared with the 44 GADECCU 2022 recommendations, for different clinical situations and therapeutic options, according to levels of evidence. A section was added with the new molecules that are about to be available.

CONCLUSIONS

This guideline has been made in order to facilitate decision-making regarding the treatment of UC, adapting and updating the guide prepared by GETECCU in the year 2020.

Therapeutic approaches for anti-sperm-antibodies in the testicular sperm aspiration rat model

Background and Aim: Anti-sperm antibodies (ASAs) treatment continued to be neglected. This study aimed to generate ASAs using the testicular sperm aspiration (TSA) rat model, which allowed for investigation of four distinct therapeutic approaches to find potential treatments for ASAs. Materials and Methods: Adult Wistar albino male rats were divided into six equal groups (n = 12). The negative control group underwent scrotal sac surgery without having their testicles punctured. Punctures were made in the remaining 5 groups, with one group left untreated to serve as the positive control group. The remaining 4 groups were treated with either dexamethasone (DEX), azathioprine (AZA), frankincense, or anti-ASAs secondary antibodies. For 10 weeks, serum samples were collected every 2 weeks for specific quantification of ASAs. Testis and epididymis tissues were collected for histopathological analysis. Results: The ASAs concentrations of the positive controls were significantly higher (p ≤ 0.001) than their negative control counterparts during the examined weeks. However, The ASAs indices (%) differed according to the treatment type. While the ASAs indices at the 2nd and 4th weeks in the AZA-treated group were significantly reduced compared to the positive control group (p ≤ 0.001), no significant differences were observed at any of the sample collection week for the DEX-treated rats. The ASAs indices were significantly decreased only at weeks 6 and 8 of treatment in the frankincense-treated group (p ≤ 0.001). In the secondary antibodies-treated group, the antibody indices were significantly decreased in all weeks except for samples collected at week 4 (p ≤ 0.001). The testosterone levels reverted to normal only in TSA rats treated with either Frankincense or secondary antibodies, as they were significantly higher than the positive controls (p ≤ 0.05). Tissue samples from the secondary antibody-treated rats showed a generally normal histological appearance. Conclusion: This study tried to offer realistic therapy suggestions; however, caution should be applied when extrapolating findings from experimental models to meet clinical requirements.

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

Single-Nucleotide Polymorphisms, c.415C > T (Arg139Cys) and c.416G > A (Arg139His), in the NUDT15 Gene Are Associated with Thiopurine-Induced Leukopenia

While nucleoside diphosphate-linked moiety X-type motif 15 (NUDT15) gene polymorphism Arg139Cys (rs116855232) is known to be a risk factor for thiopurine-induced severe leukopenia, association with the NUDT15 gene polymorphism Arg139His (rs147390019) has not yet been clarified. In addition, the accuracy of TaqMan PCR to assess these two polymorphisms has not been investigated. In this study, we evaluated TaqMan PCR for detection of the NUDT15 single-nucleotide polymorphisms (SNPs) and examined the clinical impact of Arg139His on thiopurine-induced leukopenia. First, we demonstrated that a TaqMan PCR assay successfully detected the Arg139His polymorphism of NUDT15 in clinical samples. Next, the NUDT15 gene polymorphisms (Arg139Cys and Arg139His) were separately analyzed by TaqMan Real-Time PCR in 189 patients from August 2018 to July 2019. The incidences of leukopenia within 2 years were 16.2, 57.9, and 100% for arginine (Arg)/Arg, Arg/cysteine (Cys), and Arg/histidine (His), respectively. The leukopenia was significantly increased in Arg/Cys and Arg/His compared with Arg/Arg. This retrospective clinical study indicated that, in addition to Arg139Cys, Arg139His may be clinically associated with a high risk of leukopenia. Pharmacogenomics will help in selecting drugs and determining the individualized dosage of thiopurine drugs.

Current evidence and clinical relevance of drug-microbiota interactions in inflammatory bowel disease

Background

Inflammatory bowel disease (IBD) is a chronic relapsing-remitting disease. An adverse immune reaction toward the intestinal microbiota is involved in the pathophysiology and microbial perturbations are associated with IBD in general and with flares specifically. Although medical drugs are the cornerstone of current treatment, responses vary widely between patients and drugs. The intestinal microbiota can metabolize medical drugs, which may influence IBD drug (non-)response and side effects. Conversely, several drugs can impact the intestinal microbiota and thereby host effects. This review provides a comprehensive overview of current evidence on bidirectional interactions between the microbiota and relevant IBD drugs (pharmacomicrobiomics).

Methods

Electronic literature searches were conducted in PubMed, Web of Science and Cochrane databases to identify relevant publications. Studies reporting on microbiota composition and/or drug metabolism were included.

Results

The intestinal microbiota can both enzymatically activate IBD pro-drugs (e.g., in case of thiopurines), but also inactivate certain drugs (e.g., mesalazine by acetylation via N-acetyltransferase 1 and infliximab via IgG-degrading enzymes). Aminosalicylates, corticosteroids, thiopurines, calcineurin inhibitors, anti-tumor necrosis factor biologicals and tofacitinib were all reported to alter the intestinal microbiota composition, including changes in microbial diversity and/or relative abundances of various microbial taxa.

Conclusion

Various lines of evidence have shown the ability of the intestinal microbiota to interfere with IBD drugs and vice versa. These interactions can influence treatment response, but well-designed clinical studies and combined in vivo and ex vivo models are needed to achieve consistent findings and evaluate clinical relevance.

Saudi Arabia consensus guidance for the diagnosis and management of adults with inflammatory bowel disease

Optimal management of inflammatory bowel disease (IBD) relies on a clear understanding and tailoring evidence-based interventions by clinicians in partnership with patients. This article provides concise guidelines for the management of IBD in adults, based on the most up-to-date information at the time of writing and will be regularly updated. These guidelines were developed by the Saudi Ministry of Health in collaboration with the Saudi Gastroenterology Association and the Saudi Society of Clinical Pharmacy. After an extensive literature review, 78 evidence-and expert opinion-based recommendations for diagnosing and treating ulcerative colitis and Crohn's disease in adults were proposed and further refined by a voting process. The consensus guidelines include the finally agreed on statements with their level of evidence covering different aspects of IBD diagnosis and treatment.

Identification of purine biosynthesis as an NADH-sensing pathway to mediate energy stress

An enhanced NADH/NAD⁺ ratio, termed reductive stress, is associated with many diseases. However, whether a downstream sensing pathway exists to mediate pathogenic outcomes remains unclear. Here, we generate a soluble pyridine nucleotide transhydrogenase from Escherichia coli (EcSTH), which can elevate the NADH/NAD⁺ ratio and meantime reduce the NADPH/NADP⁺ ratio. Additionally, we fuse EcSTH with previously described LbNOX (a water-forming NADH oxidase from Lactobacillus brevis) to resume the NADH/NAD⁺ ratio. With these tools and by using genome-wide CRISPR/Cas9 library screens and metabolic profiling in mammalian cells, we find that accumulated NADH deregulates PRPS2 (Ribose-phosphate pyrophosphokinase 2)-mediated downstream purine biosynthesis to provoke massive energy consumption, and therefore, the induction of energy stress. Blocking purine biosynthesis prevents NADH accumulation-associated cell death in vitro and tissue injury in vivo. These results underscore the pathophysiological role of deregulated purine biosynthesis in NADH accumulation-associated disorders and demonstrate the utility of EcSTH in manipulating NADH/NAD⁺ and NADPH/NADP⁺.

Classic drugs in the time of new drugs: real-world, long-term outcomes of thiopurine monotherapy in 1016 patients with inflammatory bowel disease

BACKGROUND

Thiopurines remain recommended as maintenance therapy in patients with inflammatory bowel disease (IBD). Despite their widespread use, long-term effectiveness data are sparse and safety is an increasingly debated topic which thwarts proper delineation in the current IBD treatment algorithm.

AIMS

To document effectiveness and safety of thiopurine monotherapy in patients with IBD, using the population-based IBD South-Limburg (IBDSL) cohort METHODS: All patients starting thiopurine monotherapy as maintenance between 1991 and 2014 were included. Therapy was defined as effective if there was no escalation to biologicals, no course of corticosteroids, no surgery and no hospitalisation for active disease during treatment. Long-term effectiveness was assessed by adjusting for differences in follow-up using Kaplan-Meier analyses. Mid- to long-term safety regarding cancer incidence and clinically relevant liver disease was documented.

RESULTS

In total, 1016 patients (643 Crohn's disease [CD]; 373 ulcerative colitis [UC]) received thiopurine monotherapy at a median of 15.2 (Q1-Q3 4.2-48.5) months after diagnosis. During follow-up, effectiveness rates at 1, 5 and 10 years were 64%, 45%, 32%, respectively, in CD and and 66%, 41%, 36%, respectively in UC. No statistically significant differences in effectiveness were observed after stratification for era of initiation (pre-biological vs biological, CD: p = 0.56; UC: p = 0.43). Sixteen non-melanoma skin cancers (incidence rate [IR] 3.33/1000 PY), five lymphomas (IR 1.04/1000 PY) and one urinary tract cancer (IR 0.21/1000 PY) were recorded. Two cases of portal hypertension were identified.

CONCLUSION

In real-world practice, thiopurine monotherapy remains effective, safe and durable for patients with CD or UC, including in the era of biologics.

Review article: latent tuberculosis in patients with inflammatory bowel diseases receiving immunosuppression-risks, screening, diagnosis and management

BACKGROUND

One quarter of the world's population has latent tuberculosis infection (LTBI). Systemic immunosuppression is a risk factor for LTBI reactivation and the development of active tuberculosis. Such reactivation carries a risk of significant morbidity and mortality. Despite the increasing global incidence of inflammatory bowel disease (IBD) and the use of immune-based therapies, current guidelines on the testing and treatment of LTBI in patients with IBD are haphazard with a paucity of evidence.

AIM

To review the screening, diagnostic practices and medical management of LTBI in patients with IBD.

METHODS

Published literature was reviewed, and recommendations for testing and treatment were synthesised by experts in both infectious diseases and IBD.

RESULTS

Screening for LTBI should be performed proactively and includes assessment of risk factors, an interferon-gamma releasing assay or tuberculin skin test and chest X-ray. LTBI treatment in patients with IBD is scenario-dependent, related to geographical endemicity, travel and other factors. Ideally, LTBI therapy should be used prior to immune suppression but can be applied concurrently where urgent IBD medical treatment is required. Management is best directed by a multidisciplinary team involving gastroenterologists, infectious diseases specialists and pharmacists. Ongoing surveillance is recommended during therapy. Newer LTBI therapies show promise, but medication interactions need to be considered. There are major gaps in evidence, particularly with specific newer therapeutic approaches to IBD.

CONCLUSIONS

Proactive screening for LTBI is essential in patients with IBD undergoing immune-suppressing therapy and several therapeutic strategies are available. Reporting of real-world experience is essential to refining current management recommendations.

Systematic review-pancreatic involvement in inflammatory bowel disease

BACKGROUND

Inflammatory bowel disease (IBD) is a chronic inflammatory immune-mediated disorder of the gut with frequent extra-intestinal complications. Pancreatic involvement in IBD is not uncommon and comprises a heterogeneous group of conditions, including acute pancreatitis (AP), chronic pancreatitis (CP), autoimmune pancreatitis (AIP) and pancreatic exocrine insufficiency (PEI); however, data on such an association remain sparse and heterogeneous.

METHOD

PubMed/MEDLINE and EMBASE databases were searched for studies investigating pancreatic involvement in patients with IBD.

RESULTS

Four thousand one hundred and twenty-one records were identified and 547 screened; finally, 124 studies were included in the review. AP is the most frequent pancreatic manifestation in IBD; the majority of AP cases in IBD are due to gallstones and drugs but cases of idiopathic AP are increasingly reported. AIP is a rare disease, but a strong association with IBD has been demonstrated, especially for type 2 and ulcerative colitis. The pathogenetic link between IBD and AIP remains unclear, but an immune-mediated pathway seems plausible. An association between CP and PEI with IBD has also been suggested, but data are to date scarce and conflicting.

CONCLUSION

This is the first systematic review of the association between IBD and pancreatic diseases. Gallstones and drugs should be considered the most probable causes of AP in IBD, with type 2 AIP also being possible.

Discovery of a Colon-Targeted Azo Prodrug of Tofacitinib through the Establishment of Colon-Specific Delivery Systems Constructed by 5-ASA-PABA-MAC and 5-ASA-PABA-Diamine for the Treatment of Ulcerative Colitis

To mitigate the systemic adverse effects of tofacitinib, 5-ASA-PABA-MAC and 5-ASA-PABA-diamine colon-specific delivery systems were constructed, and tofacitinib azo prodrugs 9 and 20a-20g were synthesized accordingly. The release studies suggested that these systems could effectively release tofacitinib in vitro, and the 5-ASA-PABA-diamine system could successfully realize the colon targeting of tofacitinib in vivo. Specifically, compound 20g displayed a 3.67-fold decrease of plasma AUC_{(tofacitinib, 0-∞)} and a 9.61-fold increase of colonic AUC_{(tofacitinib, 0-12h)}, compared with tofacitinib at a molar equivalent oral dose. Moreover, mouse models suggested that compound 20g (1.5 mg/kg) could achieve roughly the same efficacy against ulcerative colitis compared with tofacitinib (10 mg/kg) and did not impair natural killer cells. These results demonstrated the feasibility of compound 20g as an effective alternative to mitigate the systemic adverse effects of tofacitinib, and 5-ASA-PABA-MAC and 5-ASA-PABA-diamine systems were proven to be effective for colon-specific drug delivery.

When disease extent is not always a key parameter: Management of refractory ulcerative proctitis

Background

Patients with ulcerative proctitis represent a sub-group of ulcerative colitis patients with specific characteristics. Disease-related symptoms, endoscopic findings and patient's personality perspectives create a difficult-to-assess condition in certain cases.

Objectives

To summarize available evidence on the management of refractory ulcerative proctitis and provide insights in treatment options.

Results

/Conclusion: Topical therapy plays a central role due to the location of the disease. However, well-established treatment options may become exhausted in a considerable proportion of ulcerative proctitis patients, indicating the need to advance to more potent therapies in order to induce and maintain clinical response and remission in these refractory cases. Systemic corticosteroids, thiopurines, calcineurin inhibitors, biologic agents and small molecules have all been tested with variable success rates. Investigational interventions as well as surgical procedures are kept as the ultimate resort in multi-treatment resistant cases. Identifying early prognostic factors that herald a disabling disease progression will help in optimizing treatment and avoiding surgery.

Low-Dose Azathioprine in Combination with Allopurinol: The Past, Present and Future of This Useful Duo

The inflammatory bowel diseases (IBD) are complex immune-mediated inflammatory diseases that are associated with significant morbidity around the world. As our understanding of IBD, and other immune-mediated inflammatory diseases, advances the number of therapeutic targets has increased which has rapidly driven the development and introduction of new therapies. While these new therapies have shown promise they come with the significant drawback of high costs. For many IBD patients around the world the cost of newer therapies is prohibitive which means treating clinicians often need to turn to optimising simpler, older, and inexpensive medications. The concept of optimising well established cheaper medications is not unique to the management of IBD as health systems all over the world look to reduce costs while simultaneously improving patient outcomes. Despite thiopurines being used in the management IBD for over 60 years, many clinicians are still hesitant to use them due to perceptions around limited efficacy and poor tolerance. One method identified to potentially increase utilisation of thiopurines involves the coadministration of allopurinol. In this review we will explore the history, pharmacology, recent studies and give recommendations for the utilisation of the usual duo of azathioprine combined with allopurinol.

Pharmacogenetics-based personalized treatment in patients with inflammatory bowel disease: A review

The development of treatment options has revolutionized the prognosis of inflammatory bowel disease (IBD). However, a particular group of patients still experience therapeutic failure or drug side effects. Although the high inter-patient variability in therapy is associated with clinical factors, including age, disease behavior, and disease duration, they attribute only a small proportion of inter-individual variability. Thus, pharmacogenetics evaluating associations between specific genetic variations and drug responses or side effects have focused on optimizing therapeutic efficacy and minimizing toxicity in IBD treatment. Thiopurine S-methyltransferase (TPMT) and nudix hydrolase 15 (NUDT15) are well-established predictive markers of thiopurine-induced myelosuppression. Low TPMT activity is related to increased 6-thioguanine nucleotide levels, subsequently leading to myelotoxicity. NUDT15 variants are strongly associated with thiopurine-induced early leukopenia in Asians, with a lower incidence of TPMT-deficient allele. The Korean Association for the Study of Intestinal Diseases guidelines recommend pretreatment determination of NUDT15 genotypes, especially in East Asians, and NUDT15 R139C measurement has been approved for clinical use since 2019. Several studies have attempted to identify powerful genetic markers for personalized medicine. In this article, we review the identified pharmacogenetics of currently available drugs, focusing on 5-aminosalicylic acid, glucocorticosteroids, thiopurines, and anti-tumor necrosis factor-alpha agents.

Anti-Inflammatory, Antioxidant, and Healing-Promoting Effects of Aloe vera Extract in the Experimental Colitis in Rats

Background. Ulcerative colitis is a worldwide chronic gastrointestinal disease characterized by variable extensions of colon mucosal inflammation. The available drugs have an incomplete response with various side effects and socioeconomic impacts. Aloe barbadensis Miller (Aloe vera) is a well-known medicinal plant with diverse pharmacological and therapeutic activities. As a result, in the current study, Aloe vera was selected to evaluate its therapeutic effects on experimental colitis in rats. Methods. This study is intended to evaluate the possible beneficial effect of Aloe vera for the treatment of experimental colitis. Trinitrobenzenesulfonic acid (TNBS) was used to induce experimental colitis in 60 of 70 Wistar rats. The rats were grouped in 7 clusters including healthy control, negative, positive control (received sulfasalazine), and test groups treated with Aloe vera extracts via oral or rectal routes. Macroscopic and histologic factors as well as the biochemical parameters were evaluated on day 7. Results. In the present study, it was found that serum levels of tumor necrosis factor-α (75 vs. 44 pg./ml), interleukin-6 (41 vs. 21 pg/ml), and nitric oxide (24 vs. 6 μm/ml) in TNBS-induced untreated colitis treatment were significantly increased as compared to healthy control. Similar patterns were also observed in malondialdehyde (76.41 vs. 236.35 μg/mg) and myeloperoxidase (4.24 vs. 29.38 U/mg) in colonic tissue. Among different treatments, rectal administration of Aloe vera extract (400 mg/kg) exhibited the best result in which serum concentration of tumor necrosis factor-α (55 pg/ml), interleukin-6 (24 pg/ml), and nitric oxide (10 μm/ml) and the levels of malondialdehyde (102.67 μg/mg), as well as myeloperoxidase (12.29 U/mg) in colon tissue, were reduced as compared to the untreated group. Also, the body weight and colon weight/length ratios were more improved in the treated group with 400 mg/kg Aloe vera extract, rectally. Conclusion. Aloe vera extract exhibited a therapeutic effect in TNBS-induced colitis, and local, rectal administration of Aloe vera extract was more effective than oral administration.

Optimal Placement of Colectomy in the Treatment of Ulcerative Colitis: a Markov Model Analysis

BACKGROUND

Treatment for moderate-to-severe ulcerative colitis (UC) includes medical therapies such as immunosuppressive agents or surgical options such as colectomy. While prior studies have indicated a mortality benefit with elective surgery, the timing and effectiveness of colectomy in the UC treatment algorithm have not been assessed. We hypothesize that the ideal placement of colectomy occurs prior to the exhaustion of all medical therapies.

METHODS

We designed a Markov model to assess the ideal position of colectomy. The base case was a 50-year-old male with steroid-dependent moderate-to-severe UC without prior treatment with immunomodulator or biologic therapies. We developed 4 separate algorithms incorporating elective colectomy: (1) prior to biologics, (2) after infliximab monotherapy failure, (3) after infliximab and azathioprine combination therapy failure, and (4) after medically refractory to all medical therapies including vedolizumab. Transition probabilities were obtained from published literature. First-order Monte Carlo simulations of 100 trials of 100,000 individuals were used to calculate quality-adjusted life-year (QALY) estimates. One-way sensitivity analyses were conducted for all variables.

RESULTS

Algorithm 3 (colectomy following combination therapy) was the preferred strategy with 1.864 QALYs (95% CI [1.863, 1.865]) over a 3-year period and the preferred strategy in the probabilistic sensitivity analysis 92.77% of the time.

CONCLUSIONS

This simulation suggests that early incorporation of colectomy for patients medically refractory to infliximab and azathioprine combination therapy may yield greater quality of life for patients with steroid-dependent UC. These findings suggest avenues for more patient-centered preference work and a combined medical-surgical approach to UC.

Increased DNA-incorporated thiopurine metabolite as a possible mechanism for leukocytopenia through cell apoptosis in inflammatory bowel disease patients with NUDT15 mutation

BACKGROUND AND AIMS

Polymorphisms in the nucleotide diphosphate-linked moiety X-type motif 15 (NUDT15) gene are associated with thiopurine-induced leukopenia in patients with inflammatory bowel disease (IBD). NUDT15-associated subcellular thiopurine metabolism has not been investigated in primary lymphocytes. We hypothesized that NUDT15 mutation increases DNA-incorporated deoxythioguanosine (dTG) and induces apoptosis in lymphocytes.

METHODS

DNA-incorporated dTG in peripheral blood mononuclear cells (PBMCs) and 6-thioguanine nucleotides (6-TGN) in red blood cells were measured in patients with IBD undergoing thiopurine treatment. The association of a single nucleotide polymorphism for NUDT15 (rs116855232) with dTG^PBMC was examined. The pro-apoptotic effect of DNA-incorporated dTG was examined ex vivo in association with NUDT15 genotypes by co-culturing patient-derived peripheral CD4⁺ T lymphocytes with 6-thioguanine (6-TG).

RESULTS

dTG^PBMC was significantly higher in NUDT15 variants than in non-variants. dTG^PBMC, but not 6-TGN^RBC, negatively correlated with peripheral lymphocyte counts (r =  - 0.31 and  - 0.12, p = 0.012 and 0.173, respectively). DNA-incorporated dTG significantly accumulated to a greater extent in lymphocytes from NUDT15 variants when co-cultured with 6-TG ex vivo than in those from non-variants and was associated with decreased proliferation and increased apoptosis.

CONCLUSION

Increased DNA-incorporated dTG may be responsible for thiopurine-induced leukocytopenia through cell apoptosis in IBD patients with NUDT15 mutation.

Importance of NUDT15 Polymorphisms in Thiopurine Treatments

Thiopurines, mercaptopurine, and azathioprine are used as immunosuppressants in the treatments of inflammatory bowel disease, rheumatoid arthritis, and organ transplantation and as chemotherapeutic drugs for the treatment of acute leukemia and chronic myeloid leukemia. This drug class sometimes causes severe adverse reactions, including bone marrow suppression and hair loss. Genetic polymorphisms of the metabolizing enzyme thiopurine S-methyltransferase have been used for predicting these reactions in Caucasians, but these allele frequencies are less frequently observed in Asian populations. Recently, nudix hydrolase 15 (NUDT15) polymorphisms have been shown to play an important role in thiopurine-induced adverse reactions in Asians. In this review, we summarize the NUDT15 studies, mainly in Asian countries, and their implementation in several countries.

Predictive factors of relapse after dose reduction of oral 5-aminosalicylic acid in patients with ulcerative colitis in the remission phase

Objectives

Useful indices to determine whether to reduce the dose of 5-aminosalicylic acid (5-ASA) in patients with ulcerative colitis (UC) during remission remain unclear. We aimed to analyze the rate and risk factors of relapse after reducing the dose of oral 5-ASA used for maintenance therapy of UC.

Methods

UC patients whose 5-ASA dose was reduced in clinical remission (partial Mayo score of ≤ 1) at our institution from 2012 to 2017 were analyzed. Various clinical variables of patients who relapsed after reducing the dose of oral 5-ASA were compared with those of patients who maintained remission. Risk factors for relapse were assessed by univariate and multivariate logistic regression analyses. Cumulative relapse-free survival rates were calculated using the Kaplan–Meier method.

Results

A total of 70 UC patients were included; 52 (74.3%) patients maintained remission and 18 (25.7%) patients relapsed during the follow-up period. Multivariate analysis indicated that a history of acute severe UC (ASUC) was an independent predictive factor for clinical relapse (p = 0.024, odds ratio: 21, 95% confidence interval: 1.50–293.2). Based on Kaplan–Meier survival analysis, the cumulative relapse-free survival rate within 52 weeks was 22.2% for patients with a history of ASUC, compared with 82.0% for those without. the log-rank test showed a significant difference in a history of ASUC (p < 0.001).

Conclusions

Dose reduction of 5-ASA should be performed carefully in patients who have a history of ASUC.

Clinical characteristics of ulcerative colitis in elderly patients

The incidence of ulcerative colitis (UC) in elderly patients is increasing. Elderly UC patients are likely to exhibit distinct features both at diagnosis and during follow-up. Age-related problems, including complications, immune dysfunction, and multidrug use, make the diagnosis and treatment of elderly UC more challenging. Suboptimal treatment considering adverse events leads to poor clinical outcome in elderly UC patients. Here, we reviewed the epidemiology, clinical presentation, medical therapy, colorectal cancer surveillance of UC in elderly patients.

Thiopurines in Inflammatory Bowel Disease. How to Optimize Thiopurines in the Biologic Era?

Thiopurines have been a cornerstone in the treatment of inflammatory bowel disease (IBD). Although they have been used for more than 50 years, there are still some unsolved issues about their efficacy and, also, some safety concerns, mainly the risk of myelosuppression and life-threatening lymphoproliferative disorders. Furthermore, the development of biological therapy raises the question whether there is still a role for thiopurines in the IBD treatment algorithm. On the other hand, limited cost and wide availability make thiopurines a reasonable option in settings of limited resources and increasing prevalence of IBD. In fact, there is a growing interest in optimizing thiopurine therapy, since pharmacogenomic findings suggest that a personalized approach based on the genotyping of some molecules involved in its metabolism could be useful to prevent side effects. Polymorphisms of thiopurine methyltransferase enzyme (TPMT) that result in low enzymatic activity have been associated with an increased risk of myelotoxicity, especially in Caucasians; however, in Asians it is assumed that the variants of nudix hydrolase 15 (NUDT15) are more relevant in the development of toxicity. Age is also important, since in elderly patients the risk of complications seems to be increased. Moreover, the primo-infection of Epstein Barr virus and cytomegalovirus under thiopurine treatment has been associated with severe lymphoproliferative disorders. In addition to assessing individual characteristics that may influence thiopurines treatment outcomes, this review also discusses other strategies to optimize the therapy. Low-dose thiopurines combined with allopurinol can be used in hypermethylators and in thiopurine-related hepatotoxicity. The measurement of metabolites could be useful to assess compliance, identify patients at risk of adverse events and also facilitating the management of refractory patients. Thioguanine is also a rescue therapy in patients with toxicity related to conventional thiopurine therapy. Finally, the current indications for thiopurines in monotherapy or in combination with biologics, as well as the optimal duration of treatment, are also reviewed.

Steroid-refractory ulcerative colitis: a critical review of national and international guideline recommendations

Es gibt zahlreiche nationale und internationale Leitlinien zu chronisch entzündlichen Darmerkrankungen, die auf vergleichbarer Evidenz sowie ähnlichen Prozeduren beruhen und daher homogen sein sollten. In dieser kritischen Übersicht wurden die Leitlinienempfehlungen aus Europa (ECCO), Deutschland, Großbritannien, Kanada, den USA und Japan zur Therapie der steroidrefraktären Colitis ulcerosa verglichen. Die meisten Leitlinien unterschieden zwischen moderater/schwerer (ambulanter) und schwerer/fulminanter Colitis in der Klinik. Die Empfehlungen zur ersten Kategorie weisen gravierende Unterschiede auf, während zur Behandlung des stationären Patienten weitgehende Übereinstimmung herrscht. Verschiedene Erklärungen für die Inkonsistenzen werden diskutiert.

Redox imbalance in Crohn's disease patients is modulated by Azathioprine

Background

Crohn's disease (CD) is a chronic inflammatory disease without a specific cause. Inflammation in these patients can disturb the oxidants/antioxidants balance and results in oxidative stress that plays a destructive role. This study aimed to evaluate the gene expression of sod1, sod2, cat, nrf2 and gp91phox in CD patients before and after Azathioprine (Aza) consumption.

Method

Peripheral bloodmononuclear cells (PBMCs) were separated from CD patients (n= 15, mean age = 33.6 ± 1.8) before and after treatment with Aza and healthy controls (n= 15, mean age = 31.5 ± 1.2). The expression levels of sod1, sod2, cat, nrf2 and gp91phox were measured in byusing real-time qRT-PCR technique.

Result

The expression levels of gp91phox (P-value < 0.001), cat (P-value < 0.05), sod1 (P-value < 0.001), nrf2 (P-value < 0.001) were significantly increased compared to control group. Following treatment with Aza, the decreased expression levels of gp91phox (P-value < 0.05), cat (P-value < 0.05), sod1(P-value < 0.001) and nrf2 (P-value < 0.001) were observed in CD patients.

Conclusion

Overall, our results showed that prescription of Azathioprine can lead to the altered expression of redox system-related genes in patients with CD.

Use of thiopurines in inflammatory bowel disease: an update

Inflammatory bowel disease (IBD), once considered a disease of the Western hemisphere, has emerged as a global disease. As the disease prevalence is on a steady rise, management of IBD has come under the spotlight. 5-Aminosalicylates, corticosteroids, immunosuppressive agents and biologics are the backbone of treatment of IBD. With the advent of biologics and small molecules, the need for surgery and hospitalization has decreased. However, economic viability and acceptability is an important determinant of local prescription patterns. Nearly one-third of the patients in West receive biologics as the first/initial therapy. The scenario is different in developing countries where biologics are used only in a small proportion of patients with IBD. Increased risk of reactivation of tuberculosis and high cost of the therapy are limitations to their use. Thiopurines hence become critical for optimal management of patients with IBD in these regions. However, approximately one-third of patients are intolerant or develop adverse effects with their use. This has led to suboptimal use of thiopurines in clinical practice. This review article discusses the clinical aspects of thiopurine use in patients with IBD with the aim of optimizing their use to full therapeutic potential.

Thiopurine monotherapy is effective in ulcerative colitis but significantly less so in Crohn's disease: long-term outcomes for 11 928 patients in the UK inflammatory bowel disease bioresource

OBJECTIVE

Thiopurines are widely used as maintenance therapy in inflammatory bowel disease (IBD) but the evidence base for their use is sparse and their role increasingly questioned. Using the largest series reported to date, we assessed the long-term effectiveness of thiopurines in ulcerative colitis (UC) and Crohn's disease (CD), including their impact on need for surgery.

DESIGN

Outcomes were assessed in 11 928 patients (4968 UC, 6960 CD) in the UK IBD BioResource initiated on thiopurine monotherapy with the intention of maintaining medically induced remission. Effectiveness was assessed retrospectively using patient-level data and a definition that required avoidance of escalation to biological therapy or surgery while on thiopurines. Analyses included overall effectiveness, time-to-event analysis for treatment escalation and comparison of surgery rates in patients tolerant or intolerant of thiopurines.

RESULTS

Using 68 132 patient-years of exposure, thiopurine monotherapy appeared effective for the duration of treatment in 2617/4968 (52.7%) patients with UC compared with 2378/6960 (34.2%) patients with CD (p<0.0001). This difference was corroborated in a multivariable analysis: after adjusting for variables including treatment era, thiopurine monotherapy was less effective in CD than UC (OR 0.47, 95% CI 0.43 to 0.51, p<0.0001). Thiopurine intolerance was associated with increased risk of surgery in UC (HR 2.44, p<0.0001); with a more modest impact on need for surgery in CD (HR=1.23, p=0.0015).

CONCLUSION

Thiopurine monotherapy is an effective long-term treatment for UC but significantly less effective in CD.

Thiopurines: Recent Topics and Their Role in the Treatment of Inflammatory Bowel Diseases

Ulcerative colitis (UC) and Crohn's disease (CD) are chronic inflammatory bowel diseases (IBD) of unknown etiology, characterized by repeated relapse and remission. The efficacy of thiopurine in IBD was first reported in the late 1960s. Thiopurines are used to alleviate the symptoms of IBD, especially UC. These drugs have a steroid-sparing potential and are widely used for the purpose of maintaining long-term remission in steroid-dependent cases. Therefore, thiopurines tend to be used long-term, but adverse events that accompany long-term use, such as lymphoproliferative disorders, must be monitored with care. In contrast, thiopurine plays a critical role in controlling the immunogenicity of biologics. Furthermore, although thiopurine is an old drug, new findings, including the prediction of serious adverse events such as severe alopecia and acute advanced leukopenia, by nudix hydrolase 15 gene polymorphism analysis, as well as the possibility of appropriate drug monitoring by detailed analysis of 6-thioguanine nucleotides have been clarified. However, the consequences of thiopurine withdrawal have not been determined and further studies, including randomized controlled trials, are necessary to answer the clinical question regarding the scenarios in which thiopurine withdrawal is possible.

NUDT15 genotyping during azathioprine treatment in patients with inflammatory bowel disease: implications for a dose-optimization strategy

Background

NUDT15 R139C is an Asian-prevalent genetic variant related to azathioprine (AZA) intolerance in patients with inflammatory bowel disease (IBD). However, it remains unclear how to utilize the genotyping results to improve the step-up dosing strategy with an already low starting dose in Asian practice.

Methods

Clinical data of eligible IBD patients who received AZA therapy and NUDT15 R139C testing were retrospectively collected. The relationship between NUDT15 genotype, AZA doses, and AZA-induced toxicity and efficacy were comprehensively analysed.

Results

A total of 159 patients were included for toxicity analysis. Compared with the wild genotype, patients heterozygous for R139C are more prone to developing myelotoxicity and alopecia (P = 0.007; P = 0.042). In particular, they had a 5.4-fold risk of developing myelotoxicity when AZA dosage was increased from 25 mg/d to 50 mg/d (P < 0.001). Regarding efficacy, 115 patients who had received AZA for >4 months and maintained clinical remission on AZA monotherapy were included for further analysis. R139C heterozygotes were finally titrated to a significantly lower dose than the wild genotype [median (interquartile range): 0.83 (0.75-0.96) vs 1.04 (0.89-1.33) mg/kg/d, P = 0.001], whereas the clinical remission rates did not differ between groups (P = 0.88).

Conclusions

IBD patients with R139C heterozygote are highly susceptible to AZA-induced myelotoxicity at an escalated dose of 50 mg/d. Thus, they may require a smaller dose increase after a starting dose of 25 mg/d. The final target dose of these patients could be set lower than that of the wild genotypes without compromising efficacy.

Evidence-based clinical practice guidelines for inflammatory bowel disease 2020

Inflammatory bowel disease (IBD) is a general term for chronic or remitting/relapsing inflammatory diseases of the intestinal tract and generally refers to ulcerative colitis (UC) and Crohn's disease (CD). Since 1950, the number of patients with IBD in Japan has been increasing. The etiology of IBD remains unclear; however, recent research data indicate that the pathophysiology of IBD involves abnormalities in disease susceptibility genes, environmental factors and intestinal bacteria. The elucidation of the mechanism of IBD has facilitated therapeutic development. UC and CD display heterogeneity in inflammatory and symptomatic burden between patients and within individuals over time. Optimal management depends on the understanding and tailoring of evidence-based interventions by physicians. In 2020, seventeen IBD experts of the Japanese Society of Gastroenterology revised the previous guidelines for IBD management published in 2016. This English version was produced and modified based on the existing updated guidelines in Japanese. The Clinical Questions (CQs) of the previous guidelines were completely revised and categorized as follows: Background Questions (BQs), CQs, and Future Research Questions (FRQs). The guideline was composed of a total of 69 questions: 39 BQs, 15 CQs, and 15 FRQs. The overall quality of the evidence for each CQ was determined by assessing it with reference to the Grading of Recommendations Assessment, Development and Evaluation approach, and the strength of the recommendation was determined by the Delphi consensus process. Comprehensive up-to-date guidance for on-site physicians is provided regarding indications for proceeding with the diagnosis and treatment.

First United Arab Emirates consensus on diagnosis and management of inflammatory bowel diseases: A 2020 Delphi consensus

Ulcerative colitis and Crohn's disease are the main entities of inflammatory bowel disease characterized by chronic remittent inflammation of the gastrointestinal tract. The incidence and prevalence are on the rise worldwide, and the heterogeneity between patients and within individuals over time is striking. The progressive advance in our understanding of the etiopathogenesis coupled with an unprecedented increase in therapeutic options have changed the management towards evidence-based interventions by clinicians with patients. This guideline was stimulated and supported by the Emirates Gastroenterology and Hepatology Society following a systematic review and a Delphi consensus process that provided evidence- and expert opinion-based recommendations. Comprehensive up-to-date guidance is provided regarding diagnosis, evaluation of disease severity, appropriate and timely use of different investigations, choice of appropriate therapy for induction and remission phase according to disease severity, and management of main complications.

Influence of allopurinol on thiopurine associated toxicity: A retrospective population-based cohort study

Aims

Thiopurines are important for treating inflammatory bowel disease, but are often discontinued due to adverse effects. Concomitant use of allopurinol might lower the risk of these unwanted effects, but large studies in the general population are lacking. The aims of this study were to evaluate rates of hepatotoxicity, myelotoxicity, pancreas toxicity and therapy persistence in adult thiopurine users with or without allopurinol.

Methods

A retrospective population‐based cohort study was conducted within current thiopurine users (Clinical Practice Research Datalink). Among these patients, co‐use of allopurinol was compared to non‐use. Hazard ratios (HRs) for hepatotoxicity, myelotoxicity and pancreatitis were derived using time‐dependent Cox proportional hazards models, and were adjusted for potential confounders. Persistence of thiopurine use was evaluated using Log‐rank statistics.

Results

Patients using thiopurines (n = 37 360) were identified of which 1077 were concomitantly taking allopurinol. A 58% decreased risk of hepatotoxicity was observed in those concomitantly taking allopurinol (HR 0.42; 95% CI 0.30–0.60; NNT 46). Rate of myelotoxicity (HR 0.96; 95% CI 0.89–1.03) was not influenced. Risk of pancreatitis was increased (HR 3.00; 95% CI 1.01–8.93; NNH 337), but was only seen in those with active gout (suggesting confounding by indication). Finally, allopurinol co‐users were able to maintain thiopurine therapy over twice as long as those not on allopurinol (3.9 years vs. 1.8 years, P < 0.0001).

Conclusion

In thiopurine users, allopurinol is associated with a 58% reduced risk of hepatotoxicity. In addition, thiopurine persistence was prolonged by 2.1 years in allopurinol users. These data support the use of allopurinol in individuals requiring thiopurine therapy.

Ulcerative Colitis-Diagnostic and Therapeutic Algorithms

BACKGROUND

Ulcerative colitis is a chronic inflammatory bowel disease with an estimated 150 000 patients in Germany alone.

METHODS

This review is based on publications about current diagnostic and therapeutic strategies for ulcerative colitis that were retrieved by a selective search in PubMed, and on current guidelines.

RESULTS

The primary goal of treatment is endoscopically confirmed healing of the mucosa. Mesalamine, in various forms of administration, remains the standard treatment for uncomplicated ulcerative colitis. Its superiority over placebo has been confirmed in meta-analyses of randomized, controlled trials. Glucocorticoids are highly effective in the acute treatment of ulcerative colitis, but they should only be used over the short term, because of their marked side effects. Further drugs are available to treat patients with a more complicated disease course of ulcerative colitis, including azathioprine, biological agents, JAK inhibitors (among them TNF antibodies, biosimilars, ustekinumab, vedolizumab, and tofacitinib), and calcineurin inhibitors. Proctocolectomy should be considered in refractory cases, or in the presence of high-grade epithelial dysplasia. Ulcerative colitis beginning in childhood or adolescence is often characterized by rapid progression and frequent comorbidities that make its treatment a special challenge.

CONCLUSION

A wide variety of drugs are now available for the treatment of ulcerative colitis, enabling the individualized choice of the best treatment for each patient. Regular surveillance colonoscopies to rule out colon carcinoma should be scheduled at intervals that depend on risk stratification.

Thiopurine Drugs in the Treatment of Ulcerative Colitis: Identification of a Novel Deleterious Mutation in TPMT

Chronic inflammatory bowel disease (IBD) includes Crohn’s disease and ulcerative colitis. Both are characterized by inflammation of part of the digestive tract lining. Azathioprine (AZA) is a well-known immunosuppressant that has been known for many years for its ability to provide long-term disease remission in IBDs, but has important side effects, most of which are related to a single nucleotide polymorphism in the gene for thiopurine methyltransferase (TPMT), which ensures the degradation and efficacy of AZA. Since a direct correlation between TPMT gene polymorphisms and the haematological toxicity of the AZA treatment has been widely demonstrated, TPMT genotyping has been made necessary prior to any introduction of AZA. The monitoring of thiopurine metabolites presents one of the factors that limit wide adaptation of these thiopurines in clinical practice. Thus, identifying patients with asymmetric metabolism could help clinicians provide an ideal treatment recommendation to improve response and reduce adverse effects. Here, we review the role of AZA in the treatment of IBD and discuss the usefulness of TPMT genotyping to guide clinical decision-making. In addition, we report the identification of a new molecular alteration, never described, TPMT mutation affecting the TPMT activity and responsible for deleterious side effects in a clinical case of a 20-year-old woman patient.