Azathioprine and 6-Mercaptopurine-induced Liver Injury: Clinical Features and Outcomes

Thiopurine Metabolite Shunting in Late Pregnancy Increases the Risk of Intrahepatic Cholestasis of Pregnancy in Women With Inflammatory Bowel Disease, and Can be Managed With Split Dosing

BACKGROUND AND AIMS

The risk of intrahepatic cholestasis of pregnancy [ICP] is increased in thiopurine-exposed pregnancies. Thiopurine 'shunting', with a 6-methylmercaptopurine [MMP] to 6-thioguanine [TGN] ratio of >11, progresses over pregnancy, and may promote ICP development. We aimed to explore the association between thiopurine exposure and ICP, including the hypothesised impact of thiopurine shunting, and identify risk minimisation strategies.

METHODS

This prospective multicentre cohort study compared thiopurine and biologic monotherapy-exposed pregnant participants. Disease activity and obstetric outcome data, thiopurine metabolites, bile acids, and transaminases were obtained before conception, in each trimester, at delivery, and postpartum. Thiopurine dose management was at the discretion of the treating physician.

RESULTS

Included were 131 thiopurine and 147 biologic monotherapy-exposed pregnancies. MMP/TGN ratio increased from preconception to third trimester [p <0.01], with approximately 25% of participants shunting in pregnancy. Second trimester split dosing led to a decrease in the median MMP/TGN ratio from 18 (interquartile range [IQR] 6-57) to 3 [IQR 2-3.5] at delivery [p = 0.04]. The risk of ICP was increased in thiopurine-exposed pregnancies (6.7% [7/105] vs 0% [0/112], p <0.001), with all ICP cases occurring in the setting of antenatal thiopurine shunting. Thiopurine dose increases (risk ratio [RR] 8.10, 95% confidence interval [CI] 1.88-34.85, p = 0.005) and shunting in third trimester [6.20, 1.21-30.73, p = 0.028] and at delivery [14.18, 1.62-123.9, p = 0.016] were associated with an increased risk of ICP.

CONCLUSIONS

Thiopurine exposure is associated with an increased risk of ICP, particularly following dose increases antenatally and with shunting in late pregnancy. The latter may be effectively managed with split dosing, although further studies are warranted.

Inflammatory Bowel Disease Therapies and Acute Liver Injury

Drug-induced liver disease (DILI) represents one of the main problems in the therapeutic field. There are several non-modifiable risk factors, such as age and sex, and all drugs can cause hepatotoxicity of varying degrees, including those for the treatment of inflammatory bowel diseases (IBD). The aim of this review is to illustrate the adverse effects on the liver of the various drugs used in the treatment of IBD, highlighting which drugs are safest to use based on current knowledge. The mechanism by which drugs cause hepatotoxicity is not fully understood. A possible cause is represented by the formation of toxic metabolites, which in some patients may be increased due to alterations in the enzymatic apparatus involved in drug metabolism. Various studies have shown that the drugs that can most frequently cause hepatotoxicity are immunosuppressants, while mesalazine and biological drugs are, for the most part, less associated with such complications. Therefore, it is possible to assume that in the future, biological therapies could become the first line for the treatment of IBD.

Mycophenolate and methotrexate are better tolerated than azathioprine in myasthenia gravis

Azathioprine is recommended as the first-line steroid-sparing immunosuppressive agent for myasthenia gravis. Mycophenolate and methotrexate are often considered as second-line choices despite widespread consensus on their efficacy. We aimed to gather real-world data comparing the tolerability and reasons for discontinuation for these agents, by performing a national United Kingdom survey of side effects and reasons for discontinuation of immunosuppressants in myasthenia gravis. Of 235 patients, 166 had taken azathioprine, 102 mycophenolate, and 40 methotrexate. The most common side effects for each agent were liver dysfunction for azathioprine (23 %), diarrhoea for mycophenolate (14 %), and fatigue for methotrexate (18 %). Women were generally more likely to experience side effects of immunosuppressants. Azathioprine was significantly more likely to be discontinued than mycophenolate and methotrexate due to side effects. There was no significant difference in treatment cessation due to lack of efficacy. This study highlights the significant side-effect burden of treatment for myasthenia gravis. Mechanisms to reduce azathioprine toxicity should be utilised, however mycophenolate and methotrexate appear to be good treatment choices if teratogenicity is not a concern. Women are disadvantaged due to higher frequency of side effects and considerations around pregnancy and breastfeeding. Treatments with improved tolerability are needed.

Exploring the role of oxidative stress and the effect of N-acetylcysteine in thiopurine-induced liver injury in inflammatory bowel disease: A randomized crossover pilot study

Thiopurine treatment is regularly complicated by drug-induced liver injury. It has been suggested that oxidative stress may play a synergistic role. To assess whether thiopurine-induced liver injury coincides with increased oxidative stress and whether co-administration with N-acetylcysteine is protective, we performed a randomized open label crossover pilot study in inflammatory bowel disease patients with thiopurine-induced increased serum liver tests. The study comprised four stages of 4 weeks. Patients received no additional therapy followed by N-acetylcysteine 1200 mg twice a day, or the other way around, alongside ongoing thiopurine treatment. The third and fourth stages comprised a washout period and thiopurine reintroduction period. Nine patients completed the study, and the addition of N-acetylcysteine decreased myeloperoxidase concentrations (33.6-24.5 pmol/L, p = 0.038). The other biomarkers remained unchanged, including thiopurine metabolites, xanthine oxidase activity, thiopurine S-methyltransferase activity and serum liver enzyme activity tests. Reintroduction of thiopurines led to an increase of F2-isoprostanes (101-157 ng/mmol, p = 0.038), but not of serum liver enzyme activity tests. Results suggests that thiopurines may increase oxidative stress and although the addition of N-acetylcysteine led to a decrease in plasma myeloperoxidase concentrations, it does not protect from thiopurine-induced increase of serum liver tests.

Hepatobiliary manifestations in patients with ulcerative colitis: a retrospective analysis

Background

Inflammatory bowel diseases (IBDs) are often associated with altered liver function tests (LFTs). There is little data on the relationship between abnormal LFT and IBD. Our study aimed to evaluate the prevalence and etiology of elevated LFT in patients with ulcerative colitis (UC) and to determine whether there is an association with clinical and demographic parameters.

Methods

The clinical records of the Gastroenterology Outpatients Clinic at a single center were reviewed and screened for patients with UC from 2005 to 2014. In total, 263 patients were included. Patients with Crohn's disease (CD), colitis indeterminate, and colitis of other origins were excluded. Abnormal LFT and liver injuries were analyzed.

Results

A cohort of 182 patients was analyzed (114 males, 68 females; mean age = 50.2 ± 16.1 years). 58 patients had already been diagnosed with a hepatobiliary disorder. Patients with a known hepatobiliary disorder suffered from UC for a significantly longer duration. Elevated LFT in patients without known hepatobiliary disorders was 69.4%. Liver injury was found in 21.8%. A transient increase in abnormal LFT was shown in 59 patients (68.6%), a persistent increase was found in 27 patients (31.4%). Treatment with thiopurines was a risk factor for persistent elevated LFT (p = 0.029), steroids had a protective impact (p = 0.037).

Conclusion

This study clearly highlights the importance of screening for hepatobiliary disorders and abnormal LFT in patients with UC, as the prevalence of hepatobiliary disorders and abnormal LFT is detected very often among this patient group.

Transjugular Intrahepatic Portosystemic Shunt is effective to treat portal hypertension due to sinusoidal obstructive syndrome

Transjugular Intrahepatic Portosystemic Shunt (TIPS) is an established procedure for the complications of portal hypertension, such as variceal bleeding, refractory ascites and hepatic hydrothorax. We report an original case of a renal transplant patient successfully treated with TIPS for portal hypertension due to sinusoidal obstructive syndrome (SOS) induced by azathioprine (AZA). By reporting this case, we wish to draw the attention of healthcare professionals managing organ transplant patients, especially nephrologists, to the possible occurrence of liver toxicity due to AZA, and to emphasize the role of TIPS as an effective therapeutic option for portal hypertension-related complications.

Azathioprine and 6-mercaptopurine-induced intrahepatic cholestasis of pregnancy: Case report and review of the literature

OBJECTIVE

Azathioprine, a prodrug of 6-mercaptopurine (6-MP), is used in the treatment of inflammatory bowel disease and may be continued during pregnancy. Acute cholestatic liver injury has been reported to occur with azathioprine. We aimed to examine azathioprine related cholestasis effect on pregnancy complications and outcome.

CASE REPORT

We present a unique case of 6-MP-induced severe intrahepatic cholestasis of pregnancy (ICP) that required meticulous combined therapy including plasma exchange. The symptoms resolved following 6-MP withdrawal. A literature review revealed 11 pregnancies complicated by early-induced severe ICP among women treated with azathioprine or 6-MP.

CONCLUSION

We recommend weekly bile acid level tests for pregnant women treated with azathioprine or 6-MP, beginning early in the second trimester of pregnancy, and the prompt discontinuation of treatment upon establishment of an ICP diagnosis.

Severe azathioprine-induced liver injury 22 months after initiation of treatment

Drug-induced liver injury (DILI) is the leading cause of acute liver failure in high-income countries. Acute cholestasis is one of the most common forms of hepatotoxicity induced by azathioprine. It usually begins during the first year of treatment, with most cases reported during the first month. We describe an uncommon case of DILI that occurred after 22 months of drug administration. A woman in her 50s was hospitalised because of jaundice and asthenia. She had been treated with azathioprine for myasthenia gravis during the last 2 years. Acute cholestatic injury was diagnosed. After ruling out most common causes of cholestasis, azathioprine was withdrawn and subsequent histological findings in liver biopsy were consistent with drug-induced cholestatic liver damage. After discontinuation of azathioprine, biochemical parameters progressively normalised and remarkable clinical improvement was achieved. With this report, we suggest that azathioprine should be considered among the causes of liver injury, despite long treatment duration.

Budesonide with Low-Dose 6-Mercaptopurine as a Possible New Treatment for IgG4-Related Sclerosing Cholangitis and Systemic IgG4-Related Disease: A Case Report

BACKGROUND Systemic IgG4-related disease is a rare disease that can affect the hepatobiliary system and may lead to tissue fibrosis and organ failure. Diagnostic criteria for IgG4-related disease are well established, and systemic glucocorticoids are recommended for initiation of treatment. Besides the beneficial properties of glucocorticoids, the long-term treatment with systemic steroids carries the risk of toxicity, especially in elderly patients, in whom IgG4-related disease is more common. Furthermore, disease relapses may occur during the tapering of steroids. Overall, the optimal treatment approach for maintenance therapy has not been clarified yet and is an area of current clinical research. CASE REPORT We present a patient with IgG4-related sclerosing cholangitis and histologically confirmed systemic (multi-organ) IgG4-related disease who was at increased risk of disease recurrence. The effects of immunosuppressants (prednisolone, 6-mercaptopurine, budesonide) on clinical symptoms, laboratory parameters (AST, ALT, AP, γGT, bilirubin), and imaging examinations (magnetic resonance cholangiography) were documented over 56 months. Control of IgG4-related sclerosing cholangitis was achieved - without systemic prednisolone - with the locally acting glucocorticoid budesonide in combination with low-dose 6-mercaptopurine. During treatment with 6-mercaptopurine, transient hepatotoxicity occurred, which was reversed by intermittent pausing and subsequent dose reduction. In addition, gangrenous cholecystitis occurred as a complication of immunosuppression and was treated by emergency cholecystectomy. CONCLUSIONS Budesonide could be a new treatment modality for IgG4-related sclerosing cholangitis. Systemic manifestations of immunoglobulin G4-related disease can be controlled with low-dose 6-mercaptopurine. Gangrenous cholecystitis may occur as a complication of immunosuppressive treatment.

Implementation of NUDT15 Genotyping to Prevent Azathioprine-Induced Leukopenia for Patients With Autoimmune Disorders in Chinese Population

Azathioprine (AZA) is commonly used for many autoimmune disorders; however, the limitation of its clinical use is due to potential toxicities, including severe leukopenia. Recent studies have identified genetic NUDT15 variants strongly associated with AZA-induced leukopenia in Asian patients. This study aimed to investigate the strength of above genetic association and evaluate the usefulness of prospective screening of the NUDT15 variants to prevent AZA-induced leukopenia in Chinese patients. AZA-induced leukopenia in patients with autoimmune disorders were enrolled from multiple medical centers in Taiwan/China between 2012 and 2017 to determine the strength of genetic association of NUDT15 or TPMT variants by whole exome sequencing (WES). Furthermore, a prospective study was conducted between 2018 and 2021 to investigate the incidence of AZA-induced leukopenia with and without genetic screening. The WES result showed the genetic variants of NUDT15 R139C (rs116855232) (P = 3.7 × 10^-25 , odds ratio (OR) = 21.7, 95% confidence interval (95% CI) = 12.1-38.8) and NUDT15 rs746071566 (P = 4.2 × 10^-9 , OR = 7.1, 95% CI = 3.7-13.7), but not TPMT, were associated with AZA-induced leukopenia and NUDT15 R139C variant shows the highest sensitivity with 92.5%. Furthermore, the targeted screening of 1,013 participants for NUDT15 R139C enabled those identified as carriers to use alternative immunosuppressants. This strategy resulted in a significant decrease in the incidence of AZA-induced leukopenia compared with historical incidence (incidence rate = from 7.6% decreased to 0.4%; P = 9.3 × 10^-20 ). In conclusion, the NUDT15 R139C variant was strongly associated with AZA-induced leukopenia in Chinese patients. The genetic screening of NUDT15 R139C followed by use of alternative immunosuppressants in identified carriers effectively decreased the incidence of AZA leukopenia for patients with autoimmune disorders.

Azathioprine Induced Pancytopenia in a Patient with Vogt-Koyanagi-Harada Disease: A Case Report

Vogt-Koyanagi-Harada disease is a multisystem autoimmune inflammatory disorder that affects the eyes, ears, skin, and the nervous system. It is a rare disease that mainly affects Asian, Hispanic, and Middle Eastern populations. Systemic steroids and immunosuppressants are frequently used to treat autoimmune diseases like this. Despite the fact that they reduce morbidity, immunosuppressants can have a number of side effects and are difficult to use, particularly when treating uncommon autoimmune illnesses. We present a case of a 56-year-old man who visited our health facility complaining of increased tears in both eyes along with bilateral blurring of vision. He was subsequently identified as having Vogt-Koyanagi-Harada disease. After prednisolone and methotrexate failed to have the desired effect, he was treated with azathioprine, which caused pancytopenia, and manifested as fever with positive blood culture for a coagulase-negative staphylococcus infection.

Keywords

case reports; pancytopenia; steroid.

Late-Onset Acute Liver Injury From Azathioprine

Azathioprine is a widely prescribed immunosuppressant. Although hepatotoxicity is rare, it commonly presents as mild asymptomatic liver enzyme elevation or acute cholestatic liver injury. We report a case of a 46-year-old woman who presented with jaundice, abdominal pain, fatigue, and elevated aminotransferases in a cholestatic pattern. Endoscopic retrograde cholangiopancreatogram demonstrated no abnormalities, and recently started medications were discontinued without improvement. Liver biopsy was performed, which was consistent with drug-induced liver injury. Despite multiple years of treatment without issue, after azathioprine was discontinued, symptoms and laboratory abnormalities resolved. This case highlights azathioprine's potential for hepatotoxicity even multiple years after initiation.

Drug-Induced Liver Injury Used in the Treatment of Inflammatory Bowel Disease

Therapeutic options for the management of inflammatory bowel disease [IBD] have been expanding in recent decades. New biological and small molecule therapies have been incorporated into the pharmacological arsenal, allowing a more personalized management, and seeking increasingly strict remission goals. However, the fear of developing adverse events represents one of the most important limitations in deciding its use by patients and by a multidisciplinary team. Despite the risk of hepatotoxicity of thiopurines and methotrexate, these drugs are still used either as monotherapy or as combined therapy with anti-tumour necrosis factor [anti-TNF] biological agents. Although drug-induced liver injury [DILI] appears to be less frequent with anti-TNF agents, newer biologics and small molecules, liver tests should be considered in the follow-up of these patients, especially regarding future combined therapy of biologics or of these drugs with small molecules. The objective of this review is to show data on the risk of developing DILI in patients with IBD who are undergoing treatment with traditional therapy or new drugs, whether biological or small molecules.

Suspected Drug-induced Liver Injury Due to 6-Mercaptopurine With a Superimposed SARS-CoV-2 Infection in a Patient With B-ALL

6-mercaptopurine is a chemotherapeutic drug that exhibits hepatotoxic effects due to its toxic metabolites. This report describes a case of suspected drug-induced liver injury exacerbated by a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. A 16-year-old male with very high risk B-cell acute lymphoblastic leukemia was admitted for hyperbilirubinemia 2 months after a 6-mercaptopurine dosage increase and found to have an active SARS-CoV-2 infection. Liver function improved throughout hospitalization and the patient was discharged on allopurinol. Following liver function after a dosage increase of hepatoxic chemotherapy and in a pediatric oncology patient with an active SARS-CoV-2 infection undergoing treatment is vital due to potential liver impact.

The Effect of Thymus vulgaris on Hepatic Enzymes Activity and Apoptosis-Related Gene Expression in Streptozotocin-Induced Diabetic Rats

Many diseases, including diabetes, are involved in the development of liver disorders through changes in the expression of genes such as apoptosis-related genes. In the present study, the effect of Thymus vulgaris (T. vulgaris) on hepatic enzyme activity and apoptosis-related gene expression in streptozotocin (STZ)-induced diabetic rats was examined. In this study, 50 adult male Wistar rats weighing approximately 200–220 g were divided into five groups. Diabetes was induced by an intraperitoneal injection of STZ (60 mg/kg). Following 18 days, all the animals in different groups were weighed and blood samples were taken from their cardiac veins. Gas chromatography-mass spectrometry (GC-MS) analysis revealed 45 different compounds in the T. vulgaris, including thymol (39.1%), p-cymene (20.63%), and γ-terpinene (14.85%). The results showed a significant increase in liver enzymes (aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (ALP)) in diabetic or STZ mice compared to the control group (healthy mice) (P < 0.0001). The levels of AST, ALT, and ALP in rats treated with 200 mg/kg and 400 mg/kg of T. vulgaris extract showed a significant decrease in these enzymes in comparison with diabetic rats (P < 0.0001). The expression of caspase 3 and 9 genes in the groups treated with thyme significantly decreased compared to diabetic mice (P < 0.0001), and the expression of B-cell lymphoma-2 (Bcl-2) in the group receiving 400 mg/kg of thyme significantly increased compared to diabetic mice (P < 0.0001). Due to its antioxidant compounds, thyme improves the liver tissue cells in STZ-induced diabetic mice by reducing caspases 3 and 9 as well as increasing Bcl-2.

Immunosuppressive Drugs

Immunosuppressant is a class of medicines that inhibit or decrease the intensity of the immune response in the body. Most of these medications are used to allow the body less likely to resist a transplanted organ. In solid organ transplantation, immunosuppressive agents are needed for the activation of early-stage immunosuppression, the management of late-stage immunosuppression or for the maintenance of organ rejection. The emergence of novel agents and improvements in immunosuppression regimens after transplantation are significant factors leading to this progress. However, these drugs also increase the risk of infection, cancers and specific adverse side effects specific to each agent in patients particularly in pregnant women and fertility issues. Corona virus disease being hot topic of debate is has given positive outcome to immunosuppressive drugs however need more attention in future. Transplant centers across the world utilize multiple immunosuppression protocols; nevertheless, each patient can require an individually formulated immunosuppression regimen to manage the advantages and possible damage of treatment thus eliminating the likelihood of their primary disease recurrence.

Liver manifestations and complications in inflammatory bowel disease: A review

Hepatobiliary manifestations are common in inflammatory bowel disease (IBD), with 30% of patients presenting abnormal liver tests and 5% developing chronic liver disease. They range from asymptomatic elevated liver tests to life-threatening disease and usually follow an independent course from IBD. The pathogenesis of liver manifestations or complications and IBD can be closely related by sharing a common auto-immune background (in primary sclerosing cholangitis, IgG4-related cholangitis, and autoimmune hepatitis), intestinal inflammation (in portal vein thrombosis and granulomatous hepatitis), metabolic impairment (in non-alcoholic fatty liver disease or cholelithiasis), or drug toxicity (in drug induced liver injury or hepatitis B virus infection reactivation). Their evaluation should prompt a full diagnostic workup to identify and readily treat all complications, improving management and outcome.

NUDT15 genetic testing-guided 6-mercaptopurine dosing in children with ALL likely to be cost-saving in China

OBJECTIVE

The cost-effectiveness of NUDT15 genetic testing-guided initial 6-mercaptopurine (6-MP) dosing in children with acute lymphoblastic leukemia (ALL) was evaluated.

METHODS

A decision tree model was used to evaluate the cost to China's medical system per quality-adjusted life-year (QALY) gained and cost per case of severe leukopenia avoided of NUDT15 genetic testing using public clinical data.

RESULTS

Genetic testing-guided initial 6-MP dosing reduced overall costs by $518.61, and prevented 0.221 cases of Grade III-IV leukopenia and increased QALY by 0.00136 per patient. Results were robust in one-way analyses and probabilistic sensitivity analyses.

CONCLUSION

NUDT15 genetic testing prior to the initial administration of 6-MP in pediatric ALL patients in China is less expensive than standard dosing without genetic testing.

Mycophenolate Mofetil Hepatotoxicity Associated With Mitochondrial Abnormality in Liver Transplant Recipients and Mice

OBJECTIVES

Mycophenolate mofetil (MMF) is a widely used immunosuppressive agent. MMF hepatotoxicity has been reported in non-transplant and renal transplant patients with minimal histologic description. This is the first study describing detailed histology and ultrastructure of MMF hepatotoxicity.

METHODS

Four liver-transplant recipients (Cases 1-4) were suspected to have MMF hepatotoxicity. Cases 1-3 (two females and one male; 4-17 years) had multiple biopsies for liver function test (LFT) abnormalities. Case 4 (female; 16 years) had a surveillance biopsy. Electron-microscopic examination (EM) was requested on Cases 1-3 for unexplained, persistent LFT elevation and histologic abnormalities despite therapy and Case 4 for unexplained histologic abnormalities despite a stable clinical course. To confirm the pathologic changes in the human allografts, livers from MMF-treated and untreated mice were also reviewed.

RESULTS

While the allograft biopsies showed nonspecific histologic changes, EM revealed unequivocal mitochondrial abnormalities similar to those seen in primary and secondary mitochondrial disorders. In Cases 1 and 2, LFTs improved after stopping and reducing MMF, respectively. In Case 3, pre- and post-MMF treatment biopsies were performed and only the post-MMF biopsy demonstrated mitochondrial abnormalities. Mitochondrial abnormality in Case 4 was subclinical. The mouse study confirmed that MMF caused various stress changes in the mitochondria; number of mitochondria/cell (mean ± standard deviation; untreated group: 58.25 ± 8.426; MMF-treated group: 76.37 ± 18.66), number of lipid droplets/cell (untreated: 0.9691 ± 1.150; MMF-treated: 3.649 ± 4.143) and sizes of mitochondria (μm, untreated: 0.8550 ± 0.3409; MMF-treated: 0.9598 ± 0.5312) were significantly increased in hepatocytes in the MMF-treated mice compared with the untreated mice (P < 0.0001).

CONCLUSIONS

Although MMF is safe for the majority of patients, MMF can cause mitochondrial stress, which may trigger more severe mitochondrial abnormalities in a small subset. MMF hepatotoxicity should be considered for MMF-treated patients with unexplained, persistent LFT abnormalities and nonspecific histologic findings. EM should be requested for these cases.

More Than Meets the Eye?

Content available: Author Audio Recording.

Efficacy of tacrolimus as maintenance therapy after cyclophosphamide for treating antineutrophil cytoplasmic antibody-associated vasculitis

Azathioprine (AZA), methotrexate, or rituximab is used for the maintenance therapy of antineutrophil cytoplasmic antibody-associated vasculitis (AAV). Although the efficacy of tacrolimus (TAC) in various autoimmune diseases has been demonstrated, there have been few reports on the efficacy of TAC in AAV. We investigated the efficacy of TAC as maintenance therapy for AAV and compared its efficacy with that of AZA.We retrospectively analyzed the medical records of 81 patients with AAV who received cyclophosphamide as induction therapy and AZA or TAC as maintenance therapy. All-cause death, relapse, and progression to end-stage renal disease (ESRD) were analyzed.Among 81 patients with AAV, 69 patients received AZA alone, 6 patients received TAC alone, and 6 patients received TAC after AZA for maintenance therapy. Overall, 11 patients (13.6%) died, 30 patients (37.0%) experienced relapse, and 16 patients (19.8%) progressed to ESRD during a median of 33.8 months. No significant differences were observed in cumulative patients', relapse-free, and ESRD-free survival rates between patients administered AZA alone and TAC alone. There were no significant differences in the cumulative patients' and relapse-free survival rate between patients who received AZA alone and TAC after AZA. However, the cumulative ESRD-free survival rate was lower in patients who received TAC after AZA than in those who received AZA alone (P = .027).Patients who received TAC as maintenance therapy showed a higher incidence of ESRD than those who received AZA; however, this might be attributed to the lack of efficacy of AZA rather than the low ESRD prevention effect of TAC.

Health outcomes of 1000 children born to mothers with inflammatory bowel disease in their first 5 years of life

OBJECTIVE

The aim of this study was to describe the long-term health outcomes of children born to mothers with inflammatory bowel disease (IBD) and to assess the impact of maternal IBD medication use on these outcomes.

DESIGN

We performed a multicentre retrospective study in The Netherlands. Women with IBD who gave birth between 1999 and 2018 were enrolled from 20 participating hospitals. Information regarding disease characteristics, medication use, lifestyle, pregnancy outcomes and long-term health outcomes of children was retrieved from mothers and medical charts. After consent of both parents, outcomes until 5 years were also collected from general practitioners. Our primary aim was to assess infection rate and our secondary aims were to assess adverse reactions to vaccinations, growth, autoimmune diseases and malignancies.

RESULTS

We included 1000 children born to 626 mothers (381 (61%) Crohn's disease, 225 (36%) ulcerative colitis and 20 (3%) IBD unclassified). In total, 196 (20%) had intrauterine exposure to anti-tumour necrosis factor-α (anti-TNF-α) (60 with concomitant thiopurine) and 240 (24%) were exposed to thiopurine monotherapy. The 564 children (56%) not exposed to anti-TNF-α and/or thiopurine served as control group. There was no association between adverse long-term health outcomes and in utero exposure to IBD treatment. We did find an increased rate of intrahepatic cholestasis of pregnancy (ICP) in case thiopurine was used during the pregnancy without affecting birth outcomes and long-term health outcomes of children. All outcomes correspond with the general age-adjusted population.

CONCLUSION

In our study, we found no association between in utero exposure to anti-TNF-α and/or thiopurine and the long-term outcomes antibiotic-treated infections, severe infections needing hospital admission, adverse reactions to vaccinations, growth failure, autoimmune diseases and malignancies.

Mechanism-Driven Read-Across of Chemical Hepatotoxicants Based on Chemical Structures and Biological Data

Hepatotoxicity is a leading cause of attrition in the drug development process. Traditional preclinical and clinical studies to evaluate hepatotoxicity liabilities are expensive and time consuming. With the advent of critical advancements in high-throughput screening, there has been a rapid accumulation of in vitro toxicity data available to inform the risk assessment of new pharmaceuticals and chemicals. To this end, we curated and merged all available in vivo hepatotoxicity data obtained from the literature and public resources, which yielded a comprehensive database of 4089 compounds that includes hepatotoxicity classifications. After dividing the original database of chemicals into modeling and test sets, PubChem assay data were automatically extracted using an in-house data mining tool and clustered based on relationships between structural fragments and cellular responses in in vitro assays. The resultant PubChem assay clusters were further investigated. During the cross-validation procedure, the biological data obtained from several assay clusters exhibited high predictivity of hepatotoxicity and these assays were selected to evaluate the test set compounds. The read-across results indicated that if a new compound contained specific identified chemical fragments (ie, Molecular Initiating Event) and showed active responses in the relevant selected PubChem assays, there was potential for the chemical to be hepatotoxic in vivo. Furthermore, several mechanisms that might contribute to toxicity were derived from the modeling results including alterations in nuclear receptor signaling and inhibition of DNA repair. This modeling strategy can be further applied to the investigation of other complex chemical toxicity phenomena (eg, developmental and reproductive toxicities) as well as drug efficacy.

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.

Predictors of azathioprine toxicity in children with autoimmune hepatitis

AIM OF THE STUDY

Azathioprine (AZA) is an important steroid-sparing drug in the management of autoimmune hepatitis (AIH). Avoidance of its adverse events that could be severe and carry a risk of mortality in a few cases is important, preferably with cheap and easy assessments that could be feasible in developing countries with the unavailability of molecular assays. Assessment of thiopurine methyltransferase (TPMT), the key enzyme for the inactivation of AZA, as a predictor of AZA toxicity had been a matter of conflict. This work aimed to study the role of TPMT serum level assessment and other host-, disease-, and treatment-related factors in predicting AZA toxicity.

MATERIAL AND METHODS

Sixty-six children with AIH, divided into two groups, were recruited. Group 1 included twelve children with AZA toxicity and group 2 included fifty-four children without AZA toxicities. Both groups were compared for demographic, clinical, laboratory, histopathological, and treatment-related factors, and serum TPMT level, measured by ELISA.

RESULTS

TPMT serum level was comparable in both groups (p = 0.363). Duration of treatment until enzyme normalization and duration of AZA therapy were significantly associated with AZA toxicity (p = 0.007 and p = 0.01, respectively). At the first follow-up treatment with AZA, total leucocyte count (TLC) and neutrophil counts were significantly lower in group 1 (p = 0.005 and p = 0.002, respectively). Moreover, the percentage reduction of TLC and neutrophil counts were significantly higher in group 1 (p < 0.001, for both).

CONCLUSIONS

Monitoring for AZA adverse events in those with the defined predictors of AZA-related adverse events is more important than TPMT assessment.

Intrahepatic cholestasis of pregnancy associated with azathioprine: A case series

BACKGROUND

Intrahepatic cholestasis of pregnancy (ICP) is characterised by otherwise unexplained maternal pruritus, increased serum bile acid concentration over 10 μmol/L and spontaneous relief of symptoms and liver abnormalities after delivery. It occurs most frequently during the third trimester and is usually not induced by medication. Besides, azathioprine is recommended as first-line immunosuppressant in patients with steroid-dependent inflammatory bowel disease and is allowed during pregnancy, in order to stabilize maternal disease.

METHODS

We reviewed all cases of ICP between 2010 and 2018 in two French perinatal centers.

RESULTS

We encountered eight pregnancies complicated by atypical ICP among patients treated with azathioprine. ICP associated with azathioprine appears to be biologically more severe and to occur earlier than "standard" ICP. Furthermore, clinical and biochemical abnormalities related to ICP disappear when azathioprine is discontinued. Azathioprine safety should be reconsidered and practitioners advised to discuss discontinuing this drug as soon as ICP diagnosis is established.

Second-line and third-line therapy for autoimmune hepatitis: A position statement from the European Reference Network on Hepatological Diseases and the International Autoimmune Hepatitis Group

Most patients with autoimmune hepatitis respond well to standard immunosuppressive therapy with steroids and azathioprine, and while untreated disease is usually fatal, patients who respond well to therapy have an excellent prognosis. However, insufficient response to standard therapy or intolerable side effects requiring dose adaptions or treatment changes occur in 10-20% of patients. While there is fairly good agreement on second-line treatment options, there is very wide variation in the indication and use of possible third-line therapies. Herein, the European Reference Network on Hepatological Diseases (ERN RARE-LIVER) and the International Autoimmune Hepatitis Group (IAIHG) outline a treatment algorithm for both children and adults that should help to standardise treatment approaches, in order to improve patient care and to enable the comparison of treatment results between scientific publications.

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.

Advancing computer-aided drug discovery (CADD) by big data and data-driven machine learning modeling

Advancing a new drug to market requires substantial investments in time as well as financial resources. Crucial bioactivities for drug candidates, including their efficacy, pharmacokinetics (PK), and adverse effects, need to be investigated during drug development. With advancements in chemical synthesis and biological screening technologies over the past decade, a large amount of biological data points for millions of small molecules have been generated and are stored in various databases. These accumulated data, combined with new machine learning (ML) approaches, such as deep learning, have shown great potential to provide insights into relevant chemical structures to predict in vitro, in vivo, and clinical outcomes, thereby advancing drug discovery and development in the big data era.

Hepatotoxicty of Agents Used in the Management of Inflammatory Bowel Disease: a 2020 Update

PURPOSE OF REVIEW

As treatment options for inflammatory bowel disease (IBD) continue to expand, the opportunity for hepatotoxicity remains a clinical concern. This review looks to update the current literature on drug-induced liver injury (DILI) and liver-related complications from current and emerging treatments for Crohn's disease (CD) and ulcerative colitis (UC).

RECENT FINDINGS

An extensive literature review on currently used medications to treat IBD and their liver-related side effects that includes mesalamine, thiopurines, certain antibiotics, methotrexate, anti-TNF agents including recently introduced biosimilars, anti-integrin therapy, anti-IL 12/IL 23 therapy, and small molecule JAK inhibitors. Hepatotoxicity remains an important clinical issue when managing patients with IBD. Clinicians need to remain aware of the potential for liver-related adverse events with various medication classes and adjust their clinical monitoring as appropriate based on the agents being used.

Drug-Induced Liver Injury in GI Practice

Although drug-induced liver injury (DILI) is a rare clinical event, it carries significant morbidity and mortality, leaving it as the leading cause of acute liver failure in the United States. It is one of the most challenging diagnoses encountered by gastroenterologists. The development of various drug injury networks has played a vital role in expanding our knowledge regarding drug-related and herbal and dietary supplement-related liver injury. In this review, we discuss what defines liver injury, epidemiology of DILI, its biochemical and pathologic patterns, and management.

Increased Risk of Liver Cirrhosis during Azathioprine Therapy for Crohn's Disease

Azathioprine is a cornerstone of the therapy of Crohn's disease. Unfortunately, infections and malignancies are relatively common adverse effects related to this drug; however, cirrhosis is exceptionally reported as a side effect. We report the case of a 49-year-old male patient with ileocolonic steno-penetrating Crohn's disease who developed hepatic cirrhosis while treated with azathioprine. After taking azathioprine for 3 years with regular follow-up, he developed pancytopenia, and liver cirrhosis was diagnosed with ultrasound, abdomen computed tomography scan, transient elastography, and liver biopsy. As all other causes of liver damage were excluded, azathioprine was believed to be the cause of liver injury and therefore was interrupted.

Frequent Offenders and Patterns of Injury

Given the liver's role in drug metabolism, it is uniquely sensitive to potential drug-induced liver injury (DILI) despite inherent protective mechanisms. In this article, we focus on the most common causes of DILI and their patterns of injury. Although not comprehensive, we attempt to cover several classes of commonly used drugs, and their associated patterns of injury and management.

Biomarkers Predictive of Response to Thiopurine Therapy in Inflammatory Bowel Disease

The complex nature of inflammatory bowel disease (IBD) often results in treatment failure for many patients. With some patients cycling through multiple therapies before achieving a sustained period of remission, the ability to predict a patient's response to therapeutics could decrease the time from active disease to clinical remission and mucosal healing. The prospect of such individualized treatment of IBD would be aided by accurate biomarkers, both fecal and serological, which have to date shown value as indicators of IBD activity. Here we review the utility of generic biomarkers for inflammation or mucosal healing, such as calprotectin, C-reactive protein (CRP), and fecal hemoglobin (fHb) as predictors of response to treatment of IBD. We further provide a deeper insight into the utility of monitoring the thiopurine treatment by thiopurine metabolites or alternative hematologic parameters. In light of multiple recent publications of biomarkers and biological therapy, our focus in this review is predicting response to thiopurine treatment only, that is, Azathioprine and 6-Mercaptopurine.

Drug-Induced Liver Injury: Highlights of the Recent Literature

Drug-induced liver injury (DILI), herbal-induced liver injury, and herbal and dietary supplement (HDS)-induced liver injury are an important aspect of drug safety. Knowledge regarding responsible drugs, mechanisms, risk factors, and the diagnostic tools to detect liver injury have continued to grow in the past year. This review highlights what we considered the most significant publications from among more than 1800 articles relating to liver injury from medications, herbal products, and dietary supplements in 2017 and 2018. The US Drug-Induced Liver Injury Network (DILIN) prospective study highlighted several areas of ongoing study, including the potential utility of human leukocyte antigens and microRNAs as DILI risk factors and new data on racial differences, the role of alcohol consumption, factors associated with prognosis, and updates on the clinical signatures of autoimmune DILI, thiopurines, and HDS agents. Novel data were also generated from the Spanish and Latin American DILI registries as well as from Chinese and Korean case series. A few new agents causing DILI were added to the growing list in the past 2 years, including sodium-glucose co-transporter-2 inhibitors, as were new aspects of chemotherapy-associated liver injury. A number of cases reported previously described hepatotoxins confirmed via the Roussel Uclaf Causality Assessment Method (RUCAM; e.g., norethisterone, methylprednisolone, glatiramer acetate) and/or the DILIN method (e.g., celecoxib, dimethyl fumarate). Additionally, much work centered on elucidating the pathophysiology of DILI, including the importance of bile salt export pumps and immune-mediated mechanisms. Finally, it must be noted that, while hundreds of new studies described DILI in 2017-2018, the quality of such reports must always be addressed. Björnsson reminds us to remain very critical of the data when addressing the future utility of a study, which is why it is so important to adhere to a standardized method such as RUCAM when determining DILI causality. While drug-induced hepatotoxicity remains a diagnosis of exclusion, the diverse array of publications that appeared in 2017 and 2018 provided important advances in our understanding of DILI, paving the way for our improved ability to make a more definitive diagnosis and risk assessment.

Diagnostic and prognostic assessment of suspected drug-induced liver injury in clinical practice

Idiosyncratic drug-induced liver injury (DILI) is a challenging liver disorder because it can present with a range of phenotypes, mimicking almost every other hepatic disease, and lacks specific biomarkers for its diagnosis. Hence, a confident DILI diagnosis is seldom possible as it relies on the precise establishment of a temporal sequence between the exposure to a given prescription drug or sometimes hidden herbal product/over the counter medication as well as the exclusion of other aetiologies of liver disease. However, an accurate diagnosis is of most importance, as prompt withdrawal of the causative agent is essential in DILI management. Indeed, DILI can be severe and even fatal or in a fraction of cases evolve to chronic damage, but specific biomarkers for predicting mortality/liver transplantation or a chronic outcome in the very early phases of DILI are not yet available. In this article, we discuss the best diagnostic and prognostic approach of a DILI suspicion by judiciously choosing and interpreting the standard tests currently used in clinical practice.

Severe cholestasis due to azathioprine in Behcet's disease

Azathioprine (AZA) is an immunosuppressive drug that is widely used in the treatment of autoimmune diseases. Although AZA is used widely, many studies reported that AZA-related hepatotoxicity is rather rare. We aimed to present a case with severe cholestatic hepatitis due to AZA use for Behcet's disease. Three weeks after starting AZA for the treatment of uveitis, the patient was admitted to our clinic with cholestasis and constitutional symptoms. In liver biopsy, findings were in accordance with drug reaction, and the AZA treatment was stopped. After 2 months, bilirubin levels and liver tests results became normal. As a result, given that AZA may cause severe cholestasis, the drug should be stopped if idiosyncrasy or hypersensitivity develops. If there is a debate in the diagnosis, histopathological evaluation of the liver would be the major issue because of the correct diagnosis of the drug toxicity and excluding other aetiologies.

Advances in drug-induced cholestasis: Clinical perspectives, potential mechanisms and in vitro systems

Despite growing research, drug-induced liver injury (DILI) remains a serious issue of increasing importance to the medical community that challenges health systems, pharmaceutical industries and drug regulatory agencies. Drug-induced cholestasis (DIC) represents a frequent manifestation of DILI in humans, which is characterised by an impaired canalicular bile flow resulting in a detrimental accumulation of bile constituents in blood and tissues. From a clinical point of view, cholestatic DILI generates a wide spectrum of presentations and can be a diagnostic challenge. The drug classes mostly associated with DIC are anti-infectious, anti-diabetic, anti-inflammatory, psychotropic and cardiovascular agents, steroids, and other miscellaneous drugs. The molecular mechanisms of DIC have been investigated since the 1980s but they remain debatable. It is recognised that altered expression and/or function of hepatobiliary membrane transporters underlies some forms of cholestasis, and this and other concomitant mechanisms are very likely in DIC. Deciphering these processes may pave the ways for diagnosis, prognosis and prevention, for which currently major gaps and caveats exist. In this review, we summarise recent advances in the field of DIC, including clinical aspects, the potential mechanisms postulated so far and the in vitro systems that can be useful to investigate and identify new cholestatic drugs.

Hepatotoxicity of Inflammatory Bowel Disease Medications

Various medications used to treat inflammatory bowel diseases have been implicated to cause hepatotoxicity. These include sulfasalazine, 5-aminosalicylic acids, fluoroquinolones, metronidazole, thiopurines, methotrexate, anti-tumor necrosis factor agents, and alpha-4 integrin inhibitors. Various types of liver injury have been reported in association with these medications including hypersensitivity reaction, hepatocellular or cholestatic disease, nodular regenerative hyperplasia, liver fibrosis/cirrhosis, portal hypertension and autoimmune liver injury. The revised Roussel Uclaf Causality Assessment Method (RUCAM) provides a scoring system to determine the likelihood of whether a drug caused liver injury. Unfortunately some of the reported liver injuries in association with these treatments have not undergone RUCAM assessment. Therefore, although some of the reports used in this review article show an association between a medication and the reported liver injury, they may not necessarily show causation. In this article, we address methods of monitoring to detect these injuries. We also discuss the prognosis and recommended management plans when liver injury occurs.

Effective long-term solution to therapeutic remission in Inflammatory Bowel Disease: Role of Azathioprine

Azathioprine (AZA) is a well-known immunosuppressant used for many years for its ability to ensure long term disease remission in inflammatory bowel diseases (IBD) at an affordable cost to the public. However, the side effect profile has raised many concerns with numerous investigations into the risk, cause and prevention of these effects. Much of the side effect profile of AZA can be linked to a single nucleotide polymorphism (SNP) in the thiopurine methyltransferase (TPMT) gene which ensures the breakdown and efficacy of AZA. Mutated TPMT alleles result in low or deficient TPMT levels which directly correlate to cytotoxity. This is a review of the role of AZA in the treatment of IBD. Knowing a patient's TPMT status allows the prescribing doctor to make an informed decision about dosage and be more alert to the signs of cytotoxicity. It is essential to include "early warning" SNP testing into common practice to ensure therapeutic efficacy.

Drug-induced cholestasis

Cholestatic drug-induced liver injury (DILI) can be a diagnostic challenge due to a large differential diagnosis, variability in clinical presentation, and lack of serologic biomarkers associated with this condition. The clinical presentation of drug-induced cholestasis includes bland cholestasis, cholestatic hepatitis, secondary sclerosing cholangitis, and vanishing bile duct syndrome. The associate mortality of cholestatic DILI can be as high as 10%, and thus prompt recognition and removal of the offending agent is of critical importance. Several risk factors have been identified for drug-induced cholestasis, including older age, genetic determinants, and properties of certain medications. Antibiotics, particularly amoxicillin/clavulanate, remain the predominant cause of cholestatic DILI, although a variety of other medications associated with this condition have been identified. In this review, we summarize the presentation, clinical approach, risk factors, implicated medications, and management of drug-induced cholestatic liver injury. (Hepatology Communications 2017;1:726-735).

Highlights of drug - and herb- induced liver injury in the literature from 2016: how best to translate new information into clinical practice?

INTRODUCTION

Over 1500 papers on drug-induced liver injury (DILI) and herb-induced liver injury (HILI) were published in 2016, many of which have the potential to impact clinical practice. Areas covered: Clinical studies and case series that lent themselves to new concepts in diagnosing, and treating DILI were selected for inclusion. Epidemiology of DILI in large prospective registries was highlighted. Causality assessment of drug hepatotoxicity remains challenging, as seen with cases of OxyELITE Pro (OEP). In 2016 updates to the Roussel Uclaf Causality Assessment Method (RUCAM) were published to aid in the accuracy of diagnosing DILI/HILI. New reports of established hepatotoxins were again discussed in 2016, including genetic risk factors for DILI with respect to antituberculous agents. Expert opinion: 2016 marked a turning point in how much credence should be placed in the current causality assessment for DILI/HILI cases. Many recognized hepatotoxins are backed by a relatively few number of literature reports. Danan and Teschke make a strong case that an updated RUCAM should remain the gold standard for diagnosing DILI/HILI going forward, although the role of expert opinion is often still needed in cases where RUCAM falls short. The field of chemoinformatics continues to evolve while we await a truly predictive and diagnostic DILI biomarker.