Clinical predictors of thiopurine-related adverse events in Crohn's disease

The Effectiveness and Safety of First-Line Thioguanine in Thiopurine-Naïve Inflammatory Bowel Disease Patients

BACKGROUND

Currently thioguanine is solely used as treatment for inflammatory bowel disease after azathioprine and/or mercaptopurine failure. This study aimed to determine the safety, effectiveness, and 12-month drug survival of thioguanine in thiopurine-naïve patients with inflammatory bowel disease.

METHODS

A retrospective cohort study was performed in thiopurine-naïve patients with inflammatory bowel disease treated with thioguanine as first thiopurine derivate. Clinical effectiveness was defined as the continuation of thioguanine without the (re)initiation of concurrent biological therapy, systemic corticosteroids, or a surgical intervention. All adverse events were categorized by the Common Terminology Criteria for Adverse Events.

RESULTS

A total of 114 patients (male 39%, Crohn's disease 53%) were included with a median treatment duration of 25 months and a median thioguanine dosage of 20 mg/d. Clinical effectiveness at 12 months was observed in 53% of patients, and 78% of these responding patients remained responsive until the end of follow-up. During the entire follow-up period, 26 patients were primary nonresponders, 8 had a secondary loss of response, and 11 patients were unable to cease therapy with systemic corticosteroids within 6 months and were therefore classified as nonresponders. After 12 months, thioguanine was still used by 86% of patients. Fifty (44%) patients developed adverse events (grade 1 or 2) and 9 (8%) patients ceased therapy due to the occurrence of adverse events. An infection was documented in 3 patients, none of them requiring hospitalization and pancytopenia occurred in 2 other patients. No signs of nodular regenerative hyperplasia or portal hypertension were observed.

CONCLUSIONS

At 12 months, first-line thioguanine therapy was clinically effective in 53% of thiopurine-naïve inflammatory bowel disease patients with an acceptable safety profile.

Feasibility of Reduced Clinical Monitoring in Patients with Inflammatory Bowel Disease Treated with Thiopurine Therapy

BACKGROUND

Outpatient visits and laboratory assessments are routinely scheduled every 3 to 4 months in thiopurine-treated patients with inflammatory bowel disease (IBD) to timely detect thiopurine-related adverse events (AEs). AEs that require therapy adjustment beyond 12 months of treatment are rare.

AIM AND METHODS

This single-center prospective cohort study evaluated the safety of a reduced 6-monthly monitoring strategy in steroid-free patients with quiescent IBD on stable dose of azathioprine, mercaptopurine, or thioguanine monotherapy. The primary outcome was thiopurine-related AEs requiring therapy adjustments during a follow-up period of 24 months. Secondary outcomes included all AEs including laboratory toxicity, disease flares until 12 months, and the net monetary benefit from this strategy concerning IBD-related health care use.

RESULTS

We enrolled 85 patients with IBD (median age 42 years, 61% Crohn's disease, 62% female), with a median disease duration of 12.5 years and median thiopurine treatment duration of 6.7 years. During follow-up, 3 patients (4%) ceased thiopurines due to AEs: recurrent infections, non-melanoma skin cancer, and gastrointestinal complaints (nausea, vomiting). At 12 months, 25 laboratory toxicities were observed (including 13% myelotoxicity, 17% hepatotoxicity); none required therapy adjustments and all were transient. A reduced monitoring strategy had a net benefit of €136 per patient.

CONCLUSION

Three patients (4%) ceased thiopurine therapy due to thiopurine-related AEs, while no laboratory toxicity required therapy adjustments. Monitoring frequency of every 6 months seems feasible in patients with stable IBD on long-term (median duration > 6 years) maintenance thiopurine therapy and may contribute to reduced patient-burden and health care costs.

Thiopurine therapy in inflammatory bowel disease in the pandemic era: Safe or unsafe?

BACKGROUND

Inflammatory bowel disease (IBD) is a chronic inflammatory condition of the gastrointestinal tract. Crohn's disease (CD) and Ulcerative colitis (UC) are the two major types affecting millions across the globe. Various immunomodulatory drugs consisting of small molecules (thiopurines, methotrexate and tofacitinib) and biologics are used to treat IBD. Thiopurines (TP) are widely used in the treatment of IBD and it plays an important role both alone and in combination with anti-TNF agents as IBD maintenance therapy. Although the advent of biologics therapy has significantly advanced the management of IBD, TP remains the mainstay of treatment in resource-limited and low economic settings. However, the recently commenced pandemic has raised uncertainty over the safety of the use of immunosuppressant drugs such as TP among healthcare care providers and patients, as there is a scarcity of data on whether IBD patients are at higher risk of COVID-19 infection or more prone to its severe outcomes.

AIM

This review aims to encapsulate evidence on the risk of COVID-19 infection and its severe prognosis in IBD patients on TP. Additionally, it also evaluates the role of TP in inhibiting the viral protease, a potential drug target, essential for the replication and pathogenesis of the virus.

CONCLUSION

Emerging evidence suggests that TP therapy is safe during the current pandemic and does not carry an elevated risk when used as monotherapy or in combination with other IBD drugs. In-vitro studies demonstrate that TP is a potential therapeutic for present and future betacoronavirus pandemics.

Liver-side of inflammatory bowel diseases: Hepatobiliary and drug-induced disorders

Hepatobiliary disorders are among the most common extraintestinal manifestations in inflammatory bowel diseases (IBD), both in Crohn’s disease and ulcerative colitis (UC), and therefore represent a diagnostic challenge. Immune-mediated conditions include primary sclerosing cholangitis (PSC) as the main form, variant forms of PSC (namely small-duct PSC, PSC-autoimmune hepatitis overlap syndrome and IgG4-related sclerosing cholangitis) and granulomatous hepatitis. PSC is by far the most common, presenting in up to 8% of IBD patients, more frequently in UC. Several genetic foci have been identified, but environmental factors are preponderant on disease pathogenesis. The course of the two diseases is typically independent. PSC diagnosis is based mostly on typical radiological findings and exclusion of secondary cholangiopathies. Risk of cholangiocarcinoma is significantly increased in PSC, as well as the risk of colorectal cancer in patients with PSC and IBD-related colitis. No disease-modifying drugs are approved to date. Thus, PSC management is directed against symptoms and complications and includes medical therapies for pruritus, endoscopic treatment of biliary stenosis and liver transplant for end-stage liver disease. Other non-immune-mediated hepatobiliary disorders are gallstone disease, whose incidence is higher in IBD and reported in up to one third of IBD patients, non-alcoholic fatty liver disease, pyogenic liver abscess and portal vein thrombosis. Drug-induced liver injury (DILI) is an important issue in IBD, since most IBD therapies may cause liver toxicity; however, the incidence of serious adverse events is low. Thiopurines and methotrexate are the most associated with DILI, while the risk related to anti-tumor necrosis factor-α and anti-integrins is low. Data on hepatotoxicity of newer drugs approved for IBD, like anti-interleukin 12/23 and tofacitinib, are still scarce, but the evidence from other rheumatic diseases is reassuring. Hepatitis B reactivation during immunosuppressive therapy is a major concern in IBD, and adequate screening and vaccination is warranted. On the other hand, hepatitis C reactivation does not seem to be a real risk, and hepatitis C antiviral treatment does not influence IBD natural history. The approach to an IBD patient with abnormal liver function tests is complex due to the wide range of differential diagnosis, but it is of paramount importance to make a quick and accurate diagnosis, as it may influence the therapeutic management.

Evolving Role of Thiopurines in Inflammatory Bowel Disease in the Era of Biologics and New Small Molecules

In recent years, with the increasing availability of biologic therapies and due to safety concerns, the role of thiopurines in the management of inflammatory bowel disease has been questioned. While acknowledging that the benefit/risk ratio of biologic therapies is very high, they are expensive and are not required by a majority of patients. Therefore, thiopurines do retain an important role as steroid-sparing and maintenance agents when used as monotherapy, and in combination therapy with biologics due to their clinical and pharmacokinetic optimization of anti-tumor necrosis factor agents in particular. Safety concerns with thiopurines are real but also relatively rare, and with careful pre-treatment screening and ongoing monitoring thiopurine benefits outweigh risks in the majority of appropriately selected patients. Measurement of newer pharmacogenomic markers such as nudix hydrolase 15 (NUDT15), when combined with knowledge of existing known mutations (e.g., thiopurine S-methyltransferase-TPMT), will hopefully minimize the risk of potentially life-threatening leukopenia by allowing for pre-treatment dosing stratification. Further optimization of thiopurine dosing via measurement of thiopurine metabolites should be performed routinely and is superior to weight-based dosing. The association of thiopurines with malignancies including lymphoproliferative disorders needs to be recognized in all patients and individualized in each patient. The decrease in lymphoma risk after thiopurine cessation provides an incentive for thiopurine de-escalation in appropriate patients after a period of prolonged deep remission. This review will summarize the current role of thiopurines in inflammatory bowel disease management and provide recommendations for commencing and monitoring therapy, and when to consider de-escalation.

Adding Thiopurine After Loss of Response to Infliximab Versus Early Combination in Treating Crohn's Disease: A Retrospective Study

BACKGROUND

Although combining thiopurine with infliximab (IFX) is considered to improve the clinical efficacy of IFX when treating Crohn's disease (CD), it also increases the risk of adverse events (AEs). We compared the efficacy and safety of delayed thiopurine addition after loss of response (LOR) to IFX with the efficacy and safety of an earlier combination of thiopurine and IFX.

METHODS

This retrospective study analyzed patients with CD who started IFX as a first-line biologic at Kyushu University Hospital between June 2002 and July 2018. Patients were assigned to either the early-combination (EC) group, who started IFX and thiopurine simultaneously, or the late-combination (LC) group, who were treated with IFX alone until they developed LOR. We compared the cumulative IFX continuation rates and AE incidence between the two groups.

RESULTS

One hundred seventy-six patients were enrolled in this study; 49 were enrolled in the EC group, and 127 were enrolled in the LC group. Disease activity at baseline did not significantly differ between the groups, nor did the cumulative IFX continuation rates differ between the groups (P = 0.30); however, the AE rate was significantly higher in the EC group than in the LC group (38.7% vs. 21.2%; P = 0.02). The severe AE rate was also higher in the EC group than in the LC group (18.3% vs 3.1%; P = 0.001).

CONCLUSION

Considering the risk-benefit balance, delayed addition of thiopurine after LOR to IFX might be an alternative strategy when using IFX to treat CD.

Pharmacotherapy of inflammatory bowel diseases: efficacy performance and safety management

Treatment of inflammatory bowel diseases IBD (Crohns disease, ulcerative colitis) is aimed at achieving clinical, endoscopic and histological remission, minimizing surgical complications, and ensuring a normal quality of life. However, the use of medical treatment is potentially associated with various adverse events, among which infectious complications, malignant neoplasms, as well as myelotoxicity, hepatotoxicity, skin lesions and others. The risk of side effects depends on the type of drug therapy (5-aminosalicylates, thiopurines, biologicals, etc.), the duration of treatment, the presence of extra-intestinal manifestations, etc. The article provides an overview of data on both the effectiveness and frequency of various side effects of the main classes of drugs in IBD, presents methods of investigation which can predict the effectiveness and development of side effects, the implementation of which can be considered as a variant of personalized therapy in IBD.

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

BACKGROUND

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

AIM

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

METHODS

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

RESULTS

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

CONCLUSION

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

Inflammatory Bowel Diseases Elevate the Risk of Developing Acute Pancreatitis: A Meta-analysis

OBJECTIVES

Increasing data suggest that acute pancreatitis (AP) occurs more frequently among patients with inflammatory bowel diseases (IBDs) than in the non-IBD population; however, currently no comprehensive meta-analysis is available.

METHODS

Systematic literature search was conducted in 4 major databases. We included observational studies sampling from the general population. Basic study characteristics and crude incidences of AP were extracted. Pooled odds ratios (ORs) with 95% confidence interval (CIs) were calculated using the random-effects model. Subgroups were set up by Crohn disease and ulcerative colitis. Heterogeneity was tested with I statistics.

RESULTS

Eight studies were eligible for the analysis. The odds of AP were 3 times higher in IBD (OR, 3.11; 95% CI, 2.93-3.30; I, 0.0%), significantly higher in Crohn disease than in ulcerative colitis (P < 0.001; OR, 4.12 vs OR, 2.61; I, 0.0%). The pooled annual incidence of AP in IBD was 210/100,000 person-years (95% CI, 84-392/100,000 person-years; I, 98.66%).

CONCLUSIONS

We confirmed that IBD elevates the risk of AP and of 100,000 IBD patients 210 AP cases are to be expected annually. Therefore, it is important to include pancreatic enzyme level measurements and radiological investigations in the workup of IBD patients with acute abdominal pain.

Increased risk of thiopurine-related adverse events in elderly patients with IBD

BACKGROUND

Thiopurines are the most widely used immunosuppressants in IBD although drug-related adverse events (AE) occur in 20%-30% of cases.

AIM

To evaluate the safety of thiopurines in elderly IBD patients METHODS: Cohort study including all adult patients in the ENEIDA registry who received thiopurines. Patients were grouped in terms of age at the beginning of thiopurine treatment, specifically in those who started thiopurines over 60 years or between 18 and 50 years of age. Thiopurine-related AEs registered in the ENEIDA database were compared.

RESULTS

Out of 48 752 patients, 1888 started thiopurines when over 60 years of age and 15 477 under 50 years of age. Median treatment duration was significantly shorter for those who started thiopurines >60 years (13 [IQR 2-55] vs 32 [IQR 5-82] months; P < .001). Patients starting >60 years had higher rates of all types of myelotoxicity, digestive intolerance and hepatotoxicity. Thiopurines were discontinued due to AEs (excluding malignancies and infections) in more patients starting >60 years (67.2% vs 63.1%; P < .001). Elderly age and female sex were independent risk factors for most AEs.

CONCLUSION

In elderly IBD patients, thiopurines are associated with an increased risk of non-infectious, non-neoplastic, AEs.

Thiopurine Therapy in Patients With Inflammatory Bowel Disease: A Focus on Metabolism and Pharmacogenetics

Thiopurines have been widely used for the maintenance of remission or steroid sparing in patients with inflammatory bowel disease. However, potential drug-related adverse events frequently interfere with their use. Indeed, drug withdrawals associated with adverse reactions have been reported in approximately 25% of patients. To balance the efficacy, safety, and tolerability of thiopurines, regular monitoring of biomarkers (complete blood cell count, liver function test, and metabolic profiles), steady dose escalation, and pretreatment thiopurine S-methyltransferase (TPMT) genotype screening have been routinely recommended. However, the complex thiopurine metabolic pathway and individual differences attributed to pharmacogenetic diversity limit the effectiveness of these strategies in the optimization of thiopurine therapy. Recently, in an effort to facilitate more accurate and personalized prediction of thiopurine response or toxicity, novel genetic markers including NUDT15 and FTO genes were discovered. These discoveries are remarkable because TPMT screening has minimal efficacy for predicting myelosuppression especially in Asian populations, despite the fact that thee populations have a higher frequency of myelosuppression than Western populations. This review focuses on the current understanding of the metabolic pathway and the pharmacogenetics of thiopurines and suggests a personalized preventive strategy against potential adverse drug reactions to optimize their therapeutic application.

Prevention of complications from use of conventional immunosuppressants: a critical review

Synthetic immunosuppressive drugs are largely used in immune-related renal diseases and in kidney transplantation. Most of these drugs have a low therapeutic index (the ratio that compares the blood concentration at which a drug becomes toxic and the concentration at which the drug is effective), which means that the drug should be dosed carefully and the patient monitored frequently. In this review, we consider the categories of synthetic immunosuppressive agents more frequently and conventionally used in clinical nephrology: glucocorticoids, Aalkylating agents (cyclophosphamide, chlorambucil), purine synthesis inhibitors (azathioprine, mycophenolate salts) and calcineurin inhibitors (cyclosporine, tacrolimus). For each category the possible side effects will be reviewed, the general and specific measures to prevent or treat the adverse events will be suggested, and the more common mistakes that may increase the risk of toxicity will be described. However, the efficacy and safety of immunosuppressive agents depend not only on the pharmacologic characteristics of single drugs but can be influenced also by the clinical condition and genetic characteristics of the patient, by the typology and severity of the underlying disease and by the interaction with other concomitantly used drugs.

Usefulness of Thiopurine Monotherapy for Crohn's Disease in the Era of Biologics: A Long-Term Single-Center Experience

BACKGROUND

Thiopurines are classically used in Crohn's disease (CD). Treatment fails in a proportion of patients either due to adverse events (AE) or lack of efficacy. Increasing use of anti-TNFα biologic drugs may have had impact on thiopurines usage.

AIM

To evaluate the evolving use of azathioprine (AZA) monotherapy in the era of biologics.

METHODS

The study retrospectively analyzed clinical records of all CD patients who started treatment with AZA monotherapy at our center since 1990. Dates of starting AZA and treatment failure (TF) were collected. We defined AZA TF if it was withdrawn due to lack of efficacy or AE, or biologics were added.

RESULTS

A total of 383 patients were included: 46.5% were males and mean age was 31 (range 17-84) years. Median follow-up was 43 (range 0.2-289) months. Overall, 147 patients (38%) experienced TF. Median cumulative survival time of AZA was 126 (95% CI 105-147) months. Proportion of patients with AZA TF increased along time: 7 patients in 1990-1995 (4.7% of all TF); 8 in 1996-2000 (5.4%); 22 in 2001-2005(15%); 41 in 2006-2010 (28%); 69 in 2011-2014 (47%) (p = 0.04). 7%, 21%, 4%, 45%, and 33.3% of patients moved to biologics in each period, respectively (χ² = 13.07; p < 0.05). Seventy-four patients (18.4%) stopped AZA due to AE, and 73(19%) due to lack of efficacy. Regarding AZA indication, prevention of postoperative recurrence obtained better results than steroid dependency (p = 0.001); perianal fistulizing CD predicted poorer outcomes (p = 0.002).

CONCLUSION

An important proportion of CD patients under AZA monotherapy experienced TF in our experience. Although AZA monotherapy remains useful for CD in the era of biologics, current clinical practice is shifting to anti-TNFα biologic drugs in an increasing proportion of patients.

The state of the art on treatment of Crohn's disease

Crohn's disease (CD) is a chronic, progressive, and destructive disease of the gastrointestinal tract. Although its incidence appears to be stable or decreasing in most countries in the North America and Europe, the incidence is rising rapidly in Asian countries. Immunomodulators and biologics are increasingly used to avoid long-term bowel damage and subsequent disability. Therapeutic drug monitoring facilitates optimizing thiopurines and anti-TNFs use. New biologic agents targeting various pathological pathways of CD are blooming in recent years, and the high cost of biologics and expiration of patents for several biologic agents have driven the utility of biosimilars for CD treatment. Here, the literature regarding the efficacy, safety, and withdrawal of the drugs, as well as the evolution of therapeutic targets will be reviewed.

Impact of age at diagnosis on natural history of patients with elderly-onset ulcerative colitis: A French population-based study

BACKGROUND

Recent population-based study of elderly-onset Crohn's disease patients reported age-related differences in disease phenotype and outcome.

AIMS

The aim was to assess the impact of age at diagnosis on natural history of elderly-onset ulcerative colitis patients with emphasis on disease presentation, phenotype and treatment.

METHODS

Elderly-onset patients with ulcerative colitis (≥60 years at diagnosis) registered in a French population-based Registry EPIMAD (1988-2006) were included. Demographic and clinical data at diagnosis and at maximal follow-up were collected using predefined questionnaire.

RESULTS

Four-hundred and sixty-five elderly-onset ulcerative colitis patients were included (median follow-up 6.2 years); 276 (59%) were <70 and 189 (41%) ≥70 years at diagnosis. Patients aged <70 years presented with more rectal bleeding (86% vs. 79%, p = .06) and abdominal pain (44% vs. 34%, p = .04) while those ≥70 years had higher rate of left-sided colitis (62% vs. 49%; p = .02). Cumulative exposure to 5-ASA, corticosteroids and immunosuppressants was similar between the groups as well as surgery rate. However, patients <70 years were significantly more steroid-resistant than older individuals (12% vs. 3%, p < .05) while no significant difference in steroid-dependency was observed.

CONCLUSION

Patients with elderly-onset ulcerative colitis differed in presentation, disease phenotype and response to medication with respect to age at diagnosis.

Mercaptopurine and inflammatory bowel disease: the other thiopurine

BACKGROUND

Data about use and effectiveness of mercaptopurine in inflammatory bowel disease are relatively limited.

AIMS

To assess the possible therapeutic indications, efficacy and safety of mercaptopurine as an alternative to azathioprine in inflammatory bowel disease.

METHODS

Retrospective observational study in patients treated with mercaptopurine in a total cohort of 1,574 patients with inflammatory bowel disease.

RESULTS

One hundred and fifty-two patients received mercaptopurine, 15.7% of these patients as an initial thiopurine, 5.3% after azathioprine failure, and 79% after azathioprine intolerance. In 52.6% of patients (n = 80), adverse effects of mercaptopurine occurred, resulting in withdrawal in 49 of them. Mercaptopurine was effective in 39% of cases (95% CI 31-48%). In the remaining patients, failure was due mainly to withdrawal due to side effects (55.1%) and therapeutic step-up (33.7%). The average total time of mercaptopurine exposure was 36 months (IQR: 2-60). Myelotoxicity with mercaptopurine was more common in patients with intermediate TPMT activity than in those with normal activity (p = 0.046).

CONCLUSIONS

In our setting, mercaptopurine is primarily used as a rescue therapy in patients with azathioprine adverse effects. This could explain its modest efficacy and the high rate of adverse effects. However, this drug is still an alternative in this group of patients, before a therapeutic step-up to biologics is considered.

Tolerability profile of thiopurines in inflammatory bowel disease: a prospective experience

OBJECTIVES

The occurrence of thiopurine-related adverse events (AEs) may complicate the management of patients with inflammatory bowel disease (IBD). We aimed to evaluate the tolerability of thiopurines in a current IBD setting.

MATERIALS AND METHODS

All consecutive patients who started a treatment with azathioprine (AZA) from January 2010 to March 2016 were entered in a prospectively maintained database, and the AEs which led to the permanent discontinuation of the drug were reported.

RESULTS

Two hundred and fifty three patients were included. Median total follow-up was 32 months (range: 0.2-75 months). At the end of the study, AZA was discontinued in 160 patients (63.2%). The main reason leading to drug withdrawal was the occurrence of AEs (109/160 patients [68.1%]; cumulative incidence among the entire cohort: 43.1%). Overall, the most frequent AEs leading to treatment withdrawal were nausea (31/253 patients, 12.3%) and subjective symptoms, i.e., poorly defined side effects such as fatigue, headache and muscle pain (20/253 patients, 7.9%). Among the 109 AZA-intolerant patients, a switch to 6-mercaptopurine (6-MP) was performed in 44 cases (40.4%). At the end of follow-up, 6-MP was discontinued in 35/44 patients (79.5%), mostly due to AEs (29/35 patients, 82.8%). Azathioprine-induced hepatic and pancreatic toxicity was associated with male gender (p = .01 and p = .03, respectively), and occurrence of nausea with Crohn's disease (p = .04).

CONCLUSIONS

Our real-life prospective cohort showed the higher cumulative incidence of thiopurine withdrawal due to AEs reported to date. Switching from AZA to 6-MP was often ineffective.

NUDT15 polymorphisms are better than thiopurine S-methyltransferase as predictor of risk for thiopurine-induced leukopenia in Chinese patients with Crohn's disease

BACKGROUND

Thiopurine-induced leukopenia is the most common dangerous adverse event in Asians. NUDT15 R139C was recently proposed to be a promising biomarker for leukopenia with thiopurine therapy in Asians, but this has not been replicated in the Chinese population.

AIM

To investigate the influence of NUDT15 R139C, thiopurine S-methyltransferase (TPMT), 6-TGN and 6-MMPR on thiopurine-induced leukopenia in Chinese patients with Crohn's disease.

METHODS

Clinical and epidemiological characteristics were reviewed from medical records. NUDT15 R139C and TPMT were genotyped. 6-TGN/6-MMPR concentrations were measured with high-performance liquid chromatography (HPLC).

RESULTS

A total of 253 patients were included, 65 (25.7%) of whom experienced leukopenia. The median follow-up with thiopurine treatment was 38.0 weeks (range, 1-192 weeks). NUDT15 R139C was strongly associated with the incidence of leukopenia (70.2% mutation vs. 12.8% wild type; P=8.61×10^-19 ; odds ratio, 10.80; 95% CI, 5.89-19.83). However, TPMT genotype was not found to be correlated with the incidence of leukopenia (P = 0.44). In subgroup of NUDT15 wild type, there was significant difference of 6TGN concentration between patients with and without leukopenia (413.0 (174.2-831.4) vs. 279.7 (77.3-666.9) pmol/8 × 10⁸ RBC, P = 0.0055). In contrast, no association was found in patients with NUDT15 R139C variant alleles (P = 0.26). 6-MMPR was not correlated with leukopenia (P = 0.84).

CONCLUSIONS

In Chinese patients, it is strongly recommended to detect NUDT15 genotype rather than TPMT before initiating thiopurine drugs. 6TGN concentration should be routinely monitored in CD patients with NUDT15 wild type. As for CT genotype, starting at low dose and careful monitoring for leukopenia and 6TGN levels is recommended.

Caring for Women with Inflammatory Bowel Disease

Ulcerative colitis and Crohn disease are chronic inflammatory diseases with typical onset in early adulthood. These diseases, therefore, can affect a woman throughout the many stages of her life, including menstruation, sexuality, pregnancy, and menopause. Unique health issues face women during these stages and can affect the course of their inflammatory bowel disease as well as treatment strategies and health maintenance. This article covers the non-pregnancy-related issues that are important in caring for women with inflammatory bowel disease. The topics of pregnancy and fertility are covered in a separate review.

Inpatient Costs for Patients with Inflammatory Bowel Disease and Acute Pancreatitis

BACKGROUND

Inflammatory bowel disease (IBD) is associated with an increased risk of acute pancreatitis (AP). Our group examined differences in length of stay and costs for patients with IBD hospitalized for AP and the general population.

METHODS

Using the National Inpatient Sample, we examined all admissions during 2005 to 2011 with a primary diagnosis of AP and codiagnosis of IBD. Continuous variables were reported as mean ± SD and compared between IBD and controls. To compare the outcomes of interest, we conducted a 1:3 propensity score matching using a greedy algorithm based on age, gender, race, number of comorbidities, procedures, insurance, income quartiles, hospital bed size, hospital location, and teaching status. Statistical analyses were performed on SAS 9.3 (Cary, NC).

RESULTS

There were 4291 hospitalizations of patients with IBD and AP over the 7-year period and 379,627 hospitalizations of patients without IBD and with AP. More patients with Crohn's disease developed AP than patients with ulcerative colitis (2145 versus 1219). The length of stay and costs for patients with AP and IBD were significantly higher than controls (5.7 days versus 4.9 days, P < 0.0001 and $29,724.89 versus $27,916.76, P < 0.0001). The percentage of patients with alcohol abuse was lower in patients with IBD than that of controls (11.8% versus 21.7%, P < 0.0001). However, the percentage of patients with IBD who were drug abusers was higher than controls (5.8% versus 4.3%, P < 0.0005).

CONCLUSIONS

Our study suggests that a codiagnosis of Crohn's disease or ulcerative colitis incurs a greater economic burden in patients with AP.