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

Epstein-Barr virus seroprevalence among inflammatory bowel disease patients in Saudi Arabia

BACKGROUND

Seroprevalence of Epstein-Barr virus (EBV) in patients with inflammatory bowel disease (IBD) is variable based on geographic distribution. There are no published data on the seroprevalence of EBV in patients with IBD in Saudi Arabia. This study aims to assess the seroprevalence of EBV in patients with IBD in a tertiary center in Saudi Arabia.

METHODS

This is a retrospective chart review of patients ≥14 years of age with a confirmed diagnosis of IBD and known EBV status at our institution from January 1, 2018, to January 1, 2023. The primary outcome was the seroprevalence of EBV in IBD. Secondary outcomes included factors associated with EBV seropositivity and rates of EBV seroconversion in originally negative patients.

RESULTS

A total of 150 patients were included (74.7% with Crohn's disease, median age 28 years [interquartile range 21-36.3]). EBV non-exposure was noted in 16.8% ( n = 25). The mean age was significantly lower in the EBV-naïve group at 26 ± 8.5 years compared to the EBV-exposed group at 31.2 ± 12.9 years ( P = 0.02). Seroprevalence of EBV was highest in patients >40 years of age (92.9%) and lowest in patients 14-25 years of age (78.2%). The rate of seroconversion in EBV-naïve patients was 16.7% after a mean follow-up time of 47.9 ± 46.3 months.

CONCLUSION

In our cohort of IBD patients, 16.8% were naïve to EBV, and young age was a significant predictor of EBV non-exposure. Our data supports the practice of assessing EBV before initiating thiopurine therapy since EBV seroprevalence is not universal in our population.

Impact of Pharmacogenomics in Clinical Practice

Polymorphisms of genes encoding drug metabolizing enzymes and transporters can significantly modify pharmacokinetics, and this can be associated with significant differences in drug efficacy, safety, and tolerability. Moreover, genetic variants of some components of the immune system can explain clinically relevant drug-related adverse events. However, the implementation of drug dose individualization based on pharmacogenomics remains scarce. In this narrative review, the impact of genetic variations on the disposition, safety, and tolerability of the most commonly prescribed drugs is reported. Moreover, reasons for poor implementation of pharmacogenomics in everyday clinical settings are discussed. The literature analysis showed that knowledge of how genetic variations can modify the effectiveness, safety, and tolerability of a drug can lead to the adjustment of usually recommended drug dosages, improve effectiveness, and reduce drug-related adverse events. Despite some efforts to introduce pharmacogenomics in clinical practice, presently very few centers routinely use genetic tests as a guide for drug prescription. The education of health care professionals seems critical to keep pace with the rapidly evolving field of pharmacogenomics. Moreover, multimodal algorithms that incorporate both clinical and genetic factors in drug prescribing could significantly help in this regard. Obviously, further studies which definitively establish which genetic variations play a role in conditioning drug effectiveness and safety are needed. Many problems must be solved, but the advantages for human health fully justify all the efforts.

Stromal inflammation, fibrosis and cancer: An old intuition with promising potential

It is now well established that the biology of cancer is influenced by not only malignant cells but also other components of the tumour microenvironment. Chronic inflammation and fibrosis have long been postulated to be involved in carcinogenesis. Chronic inflammation can promote tumorigenesis via growth factor/cytokine-mediated cellular proliferation, apoptotic resistance, immunosuppression; and free-radical-induced oxidative deoxyribonucleic acid damage. Fibrosis could cause a perturbation in the dynamics of the tumour microenvironment, potentially damaging the genome surveillance machinery of normal epithelial cells. In this review, we will provide an in-depth discussion of various diseases characterised by inflammation and fibrosis that have been associated with an increased risk of malignancy. In particular, we will present a comprehensive overview of the impact of alterations in stromal composition on tumorigenesis, induced as a consequence of inflammation and/or fibrosis. Strategies including the application of various therapeutic agents with stromal manipulation potential and targeted cancer screening for certain inflammatory diseases which can reduce the risk of cancer will also be discussed.

Recent updates on correlation between reactive oxygen species and synbiotics for effective management of ulcerative colitis

Ulcerative colitis (UC) is presently considered a multifactorial pathology, which may lead to persistent inflammatory action of the gastrointestinal tract (GIT) because of an improperly managed immunological reactivity to the intestinal microbiota found in the GIT. The immune response to common commensal microbes plays an essential role in intestinal inflammation related to UC synbiotics, and it is an important element in the optimal therapy of UC. Therefore, synbiotics, i.e., a mixture of prebiotics and probiotics, may help control the diseased state. Synbiotics alleviate the inflammation of the colon by lowering the reactive oxygen species (ROS) and improving the level of antioxidant enzymes such as catalase (CAT), glutathione peroxidase (GPX), and superoxide dismutase (SOD). Prebiotic supplementation is not a common practice at the moment, despite numerous research findings proving that the benefits of both probiotics and prebiotics encourage their continued existence and positioning in the GIT, with positive effects on human health by managing the inflammatory response. However, the fact that there have been fewer studies on the treatment of UC with different probiotics coupled with selected prebiotics, i.e., synbiotics, and the outcomes of these studies have been very favorable. This evidence-based study explores the possible role of ROS, SOD, and synbiotics in managing the UC. The proposed review also focuses on the role of alteration of gut microbiota, antioxidant defense in the gastrointestinal tract, and the management of UC. Thus, the current article emphasizes oxidative stress signaling in the GI tract, oxidative stress-based pathomechanisms in UC patients, and UC therapies inhibiting oxidative stress' effects.

Implementation of pharmacogenomics: Where are we now?

Pharmacogenomics (PGx), examining the effect of genetic variation on interpatient variation in drug disposition and response, has been widely studied for several decades. However, as cost, as well as turnaround time associated with PGx testing, has significantly improved, the use of PGx in the clinical setting has been gaining momentum. Nevertheless, challenges have emerged in the broader clinical implementation of PGx. In this review, we will outline current models of PGx delivery and methodologies of evaluation, and discuss clinically relevant PGx tests and associated medications. Additionally, we will describe our approach for the broad implementation of pre-emptive DPYD genotyping in patients taking fluoropyrimidines in Ontario, Canada, as an example of clinically actionable PGx testing with sufficient clinical evidence of patient benefit that can become a new standard of patient care. We will highlight challenges associated with PGx testing, including a lack of diversity in PGx studies as well as general limitations that impact the broad adoption of PGx testing. Lastly, we examine the future of PGx, discussing new clinical targets, methodologies and analysis approaches.

A report on the potential of Rac1/pSTAT3 protein levels in T lymphocytes to assess the pharmacodynamic effect of thiopurine therapy in Inflammatory Bowel Disease patients

The thiopurine derivatives azathioprine (AZA), mercaptopurine (MP) and tioguanine (TG) remain standard treatment of inflammatory bowel disease (IBD). The immune suppressive effect of thiopurines is primarily based on blocking the Ras-related C3 botulinum toxin substrate 1 (Rac1) causing apoptosis of T lymphocytes by inhibition of the phosphorylated downstream transcription factor Signal Transducer and Activator of Transcription 3 (pSTAT3). A functional pharmacodynamic marker in T lymphocytes may be useful to predict therapeutic outcome of thiopurine therapy. The aim of this study was to explore whether protein levels of Rac1 and pSTAT3 in T lymphocytes may be applied as a specific pharmacodynamic marker for thiopurine therapy in IBD patients. Rac1 and pSTAT3 protein levels in T lymphocytes were explored in 57 IBD patients (median age 51 years, 56% female), subdivided into six groups based on IBD activity and its treatment: patients with active disease without IBD maintenance medication (1) or patients in remission on AZA/MP (2), TG (3), infliximab (IFX) (4), thiopurine and IFX combination-treatment (5) or without IBD medication (6). Reference values were obtained from healthy subjects. Rac1 and pSTAT3 protein levels in T lymphocytes from patients on thiopurine monotherapy (group 2 and 3) were compared to the other groups, and to healthy subjects. Absolute Rac1 and pSTAT3 protein levels showed no differences between the thiopurine monotherapy groups when compared to patients with active disease. However, the ratio of Rac1 and pSTAT3 protein levels was lower in thiopurine patients groups compared to patients with active disease. Rac1-corrected pSTAT3 protein levels may serve as a pharmacodynamic marker of thiopurine monotherapy and may be a potential tool to predict therapeutic effectiveness in IBD patients.

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.

Transmembrane serine protease 2 and angiotensin-converting enzyme 2 anti-inflammatory receptors for COVID-19/inflammatory bowel diseases treatment

Inflammatory bowel diseases (IBD) refer to a subgroup of chronic, progressive, long-term, and relapsing inflammatory disorders. IBD may spontaneously grow in the colon, and in severe cases may result in tumor lesions such as invasive carcinoma in inflamed regions of the intestine. Recent epidemiological reports indicate that old age and underlying diseases such as IBD contribute to severity and mortality in patients with coronavirus disease 2019 (COVID-19). Currently, the ongoing COVID-19 pandemic caused serious morbidity and mortality worldwide. It has also been shown that the transmembrane serine protease 2 is an essential factor for viral activation and viral engulfment. Generally, viral entry causes a 'cytokine storm' that induces excessive generation of proinflammatory cytokines/chemokines including interleukin (IL)-6, IL-2, IL-7, tumor necrosis factor-α, and interferon-γ. Future research could concentrate on developing inflammatory immunological responses that are efficient to encounter COVID-19. Current analysis elucidates the role of inflammation and immune responses during IBD infection with COVID-19 and provides a list of possible targets for IBD-regulated therapies in particular. Data from clinical, in vitro, and in vivo studies were collected in English from PubMed, Google Scholar, Scopus, and the Cochrane library until May 2021.