6-Thioguanine levels in pediatric IBD patients: adherence is more important than dose

Thiopurine adherence: high prevalence with low impact in UC outcomes

Introduction Thiopurines are used as maintenance therapy in patients with ulcerative colitis (UC). There are contradictory results regarding the relationship between adherence to treatment and risk of relapse. Objectives To quantify and evaluate the trends in thiopurines prescription rates, and to determine the impact and risk factors of non-adherence. Methods Analytical, observational and retrospective study of UC patients, on thiopurines, included in the ENEIDA single-center registry from October 2017 to October 2019. We included adult patients under clinical remission at the beginning of the study on thiopurines maintenance treatment for at least 6 months before recruitment. Adherence was evaluated with an electronic pharmaceutical prescription system. Adherence was considered when 80% or more of the prescribed medication was dispensed at the pharmacy. Kaplan-Meier curves and a regression model were used to examine year-to-year treatment dispensation and identify factors associated to non-adherence. Results A total of 41 patients were included, of whom 71% were males with a mean age of 44 (14) and 26.8% were concomitantly managed with biological therapy. Overall, 22% were non-adherent to thiopurines. No predictive factors of non-adherence were identified. Adherence rate did not correlate with disease activity for two years follow-up (OR 1.6; 95CI =0.3-9.1). Left-sided colitis and concomitant biological treatment were related with disease relapses (p ≤0.01). Conclusion The adherence to thiopurines in UC patients is high (78%). Non-adherence is not related to clinical or pharmacological factors. Adherence rate was not associated with disease activity.

Longitudinal Barriers to Thiopurine Adherence in Adolescents With Inflammatory Bowel Diseases

Objectives

Cross-sectionally, more adherence barriers are associated with lower medication adherence. However, little is known about longitudinal associations between adherence barriers and adherence. Among adolescents with inflammatory bowel diseases (IBD), this study examined both (1) how time-varying self-reported adherence barriers affect daily thiopurine adherence and (2) how adherence barriers at baseline affect daily thiopurine adherence over a six-month period.

Methods

Eighty-one adolescents 11-18 years old prescribed a once-daily oral IBD maintenance medication participated in a six-month observational study. Adherence barriers were self-reported monthly via the Medication Adherence Measure (MAM): Medication Subscale. Daily adherence estimates were collected via Medication Event Monitoring System (MEMS) Track Caps.

Results

Generalized linear mixed modeling indicated that time alone did not significantly predict whether one was more likely to be adherent (p = .602). However, increasing adherence barriers lowered the likelihood that a participant would be adherent on a given day, and the interaction between time and barriers predicted likelihood of adherence on a given day (p < .01). Specifically, when participants reported no adherence barriers at baseline, adherence did not significantly change over time (p = .369). However, when barriers were endorsed, adherence decreased over time (p < .01).

Conclusions

Fewer adherence barriers over time predicted greater likelihood of adherence on a given day, which is consistent with previous cross-sectional research. Routine assessment of barriers to adherence over the course of adolescence is critical in addressing suboptimal adherence behavior in youth with IBD.

Longitudinal non-adherence predicts treatment escalation in paediatric ulcerative colitis

BACKGROUND

Medication non-adherence in paediatric ulcerative colitis (UC) has been associated with negative health outcomes including flares in disease activity. However, no studies to date have examined longitudinal adherence to maintenance medication in a prospective controlled trial.

AIMS

To determine whether objectively measured adherence to standardised mesalazine (mesalamine) therapy over time was related to remission at 52 weeks and the need for treatment escalation in newly diagnosed paediatric patients with UC METHODS: PROTECT (NCT01536535) was a prospective, inception cohort, multi-site study of paediatric patients aged 4-17 years with newly diagnosed UC followed for 52 weeks. Patients received standardised mesalazine, with pre-established criteria for escalation to thiopurines or anti-TNFα inhibitors. Patients used pill bottles with electronic caps to monitor mesalazine adherence. We tested whether longitudinal adherence to mesalazine predicted steroid-free remission at week 52 (i.e. quiescent disease on mesalazine alone with no corticosteroids ≥4 weeks prior) and need for treatment escalation (i.e. introduction of immunomodulators, calcineurin-inhibitors or anti-TNFα inhibitors).

RESULTS

Among 268 patients, average mesalazine adherence trajectories did not predict week 52 steroid-free remission. Declining adherence over time strongly predicted treatment escalation (β = -.037, P = .001). By month 6, adherence rate ≤85.7% was associated with treatment escalation.

CONCLUSIONS

Non-adherence may have affected therapeutic efficacy of standardised mesalazine, thereby contributing to need for treatment escalation. Routine adherence monitoring for at least 6 months following treatment initiation and addressing adherence difficulties early in the disease course are recommended.

The Transition of the Gastrointestinal Patient from Pediatric to Adult Care

Transition is the long process of developing independent self-management skills whereas transfer is the actual move from pediatric to adult-centered provider. Structured anticipated transition works best with timelines of tasks to master and discussion of the stylistic differences between pediatric and adult practices. Disease-specific issues need to be addressed, such as earlier timelines for diet-based therapies, parental support for critical illnesses, and differences in therapeutic strategies.

Measurement of red blood cell 6-thioguanine nucleotide is beneficial in azathioprine maintenance therapy of Chinese Crohn's disease patients

OBJECTIVE

It remains controversial whether 6-thioguanine nucleotide (6-TGN)-based dose adjusting can be beneficial in azathioprine (AZA) therapy. This study is designed to assess the role of 6-TGN concentrations in maintaining clinical remission in Chinese patients with Crohn's disease (CD).

MATERIAL AND METHOD

We performed a prospective observational study and collected data of CD patients in the First Affiliated Hospital of Anhui Medical University from June 2013 to April 2014. Demographic material, CD activity index, 6-TGN concentration, and laboratory tests were recorded at baseline and at each visit. In addition, 6-TGN was measured when drug adverse effects occurred. All patients achieved maintenance stage were administered a stable AZA dose at least 3 months before enrollment and were followed up at least 12 months. Thiopurine S-methyltransferase (TPMT) genotype was measured before AZA treatment.

RESULTS

Sixty-nine patients receiving maintenance therapy were analyzed. A positive correlation was found between 6-TGN levels and AZA dose (r = 0.258, p = 0.032). The mean 6-TGN concentration was 302.06 ± 115.84 in the remission group vs. 264.94 ± 164.53 pmol/8 × 10(8) RBC in those with active disease (t = 0.847, p = 0.40), and 197.74 ± 66.54 pmol/8 × 10(8) RBC in patients who relapsed vs. 310.26 ± 122.38 pmol/8 × 10(8) RBC for those in sustained remission (t= -2.541, p = 0.013). In the leukopenia group, the 6-TGN concentration was 469.11 ± 115.53 pmol/8 × 10(8) RBC vs. 257.31 ± 83.74 pmol/8 × 10(8) RBC in the non-leukopenia group (t = 7.622, p < 0.001). There was a significant negative correlation between leukocyte count and 6-TGN concentration (r= -0.326, p = 0.006).

CONCLUSIONS

6-TGN measurement is a helpful method of preventing disease relapse and avoiding leukopenia in individual azathioprine maintenance therapy.

Serum Infliximab, Antidrug Antibodies, and Tumor Necrosis Factor Predict Sustained Response in Pediatric Crohn's Disease

BACKGROUND

Serum infliximab (s-IFX) levels, antibodies to IFX (ATI), and inflammatory markers are important in predicting clinical outcomes in adults, but their roles in pediatric Crohn's disease (CD) require further study. The primary aim of this study was to determine the association between serologic parameters during induction and ongoing IFX therapy at 12 months in pediatric CD.

METHODS

S-IFX, ATI, serum tumor necrosis factor alpha (s-TNF-α), and C-reactive protein were measured at IFX initiation, 10 weeks, 6 months, and 12 months in a prospective cohort study of children with CD at a single tertiary care center.

RESULTS

At 12 months, 60 of 77 participants (78%) remained on IFX. Participants who completed 12 months of IFX had higher 10-week median s-IFX levels (20.40 μg/mL; interquartile range [IQR], 11.20-35.00] versus 8.70 μg/mL; IQR 0.90-16.90; P = 0.01), a greater proportion with undetectable 10-week ATI (P = 0.008), and a greater median change in s-TNF-α between baseline and week 10 (-5.96 pg/mL; IQR, -8.73 to -4.17 versus -1.76 pg/mL; IQR, -5.60 to 0.30; P = 0.006). Receiver operating characteristic analysis to predict ongoing IFX at 12 months showed area under the curve (95% confidence interval) for 10-week s-IFX and change in s-TNF-α from baseline to 10 weeks to be 0.71 (0.54-0.88) and 0.74 (0.58-0.91), respectively. C-reactive protein was not associated with ongoing therapy.

CONCLUSIONS

ATI, s-IFX, and s-TNF-α during IFX induction are associated with 12-month clinical outcomes in pediatric CD. Future studies are needed to further define the clinical role of s-TNF-α measurement and to compare the clinical utility of 10 and 14-week ATI and s-IFX levels.

Adherence to Oral Maintenance Treatment in Adolescents With Inflammatory Bowel Disease

OBJECTIVES

The aim of this study was to systematically review the rates of nonadherence to oral maintenance treatment in adolescents with inflammatory bowel disease (IBD), and to describe perceived barriers to adherence and psychosocial factors involved.

METHODS

The article considered studies published in MEDLINE, Embase, and PsycINFO up to March 2015. Studies that had collected data on adherence to thiopurines or aminosalicylates in a cohort of adolescents with IBD. Case reports and case series were excluded.

RESULTS

A total of 25 studies were included. Lack of uniformity of outcome measures made pooling of data impossible. Rates of medication nonadherence ranged from 2% to 93%. The most frequently reported barriers were "just forgot," "wasn't home," and "interferes with activity." Family dysfunction, peer victimization, poor health-related quality of life, poor child-coping strategies, anxiety, and depressive symptoms were associated with medication nonadherence.

CONCLUSIONS

Nonadherence to oral maintenance therapy in adolescents with IBD is a significant health care problem and can lead to unnecessary escalation in therapy. Difficulties in family and social interactions, and psychosocial dysfunction can jeopardize IBD treatment outcome and should receive attention early in the course of the disease.

Treatment Nonadherence in Inflammatory Bowel Disease: Identification, Scope, and Management Strategies

Treatment adherence is of critical importance in the management of patients with IBD. Poor adherence can lead to increased disease activity, loss of response to therapy, and increased costs of care. It has been well established that adherence to long-term therapy for chronic illnesses is extremely poor, averaging around 50% in developed countries. Measured rates of nonadherence in IBD are similar, but vary depending on the type of therapy and the population being observed. This article reviews the scientific data on treatment nonadherence in IBD. The methods commonly used to evaluate treatment adherence investigation are reviewed. The consequences and scope of treatment nonadherence are summarized. Finally, the scientific data on management strategies to address the problem of treatment nonadherence are explored.

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

AIMS

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

METHODS

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

RESULTS

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

CONCLUSION

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

Medication adherence among pediatric patients with sickle cell disease: a systematic review

OBJECTIVES

Describe rates of adherence for sickle cell disease (SCD) medications, identify patient and medication characteristics associated with nonadherence, and determine the effect of nonadherence and moderate adherence (defined as taking 60%-80% of doses) on clinical outcomes.

METHODS

In February 2012 we systematically searched 6 databases for peer-reviewed articles published after 1940. We identified articles evaluating medication adherence among patients <25 years old with SCD. Two authors reviewed each article to determine whether it should be included. Two authors extracted data, including medication studied, adherence measures used, rates of adherence, and barriers to adherence.

RESULTS

Of 24 articles in the final review, 23 focused on 1 medication type: antibiotic prophylaxis (13 articles), iron chelation (5 articles), or hydroxyurea (5 articles). Adherence rates ranged from 16% to 89%; most reported moderate adherence. Medication factors contributed to adherence. For example, prophylactic antibiotic adherence was better with intramuscular than oral administration. Barriers included fear of side effects, incorrect dosing, and forgetting. Nonadherence was associated with more vaso-occlusive crises and hospitalizations. The limited data available on moderate adherence to iron chelation and hydroxyurea indicates some clinical benefit.

CONCLUSIONS

Moderate adherence is typical among pediatric patients with SCD. Multicomponent interventions are needed to optimally deliver life-changing medications to these children and should include routine monitoring of adherence, support to prevent mistakes, and education to improve understanding of medication risks and benefits.

Thiopurine metabolite ratios for monitoring therapy in pediatric Crohn disease

OBJECTIVES

Thiopurines (azathioprine, 6-mercaptopurine) are a mainstay of treatment in Crohn disease (CD). Monitoring intracellular metabolite (6-thioguanine nucleotides [6-TGN] and 6-methylmercaptopurine [6-MMP]) levels can help optimize therapeutic efficacy and minimize potential toxicity. Determination of 6-MMP/6-TGN ratios may provide additional useful information, such as the identification of individuals with excessive thiopurine methyltransferase activity and disadvantageous 6-MMP overproduction. These patients are at increased risk of therapeutic failure and hepatotoxicity. The aim of the study was to evaluate the correlation of 6-MMP/6-TGN ratios with therapeutic efficacy and risk of hepatotoxicity in CD.

METHODS

The present study was a single-center cross-sectional study including pediatric patients with CD studied prospectively with clinical and laboratory assessments along with serial measurements of 6-MMP and 6-TGN. Clinical response was determined using established clinical indices.

RESULTS

The study included 238 pediatric patients with CD with a total of 1648 evaluation points. The patients were in steroid-free remission at 59.1% of the evaluation points. 6-MMP/6-TGN ratios of 4 to 24 were protective against relapse (odds ratio [OR] 0.52, 95% confidence interval [CI] -0.39 to 0.69, P = 0.001). Hepatotoxicity was associated with high 6-MMP levels (>3919  pmol/8 × 10 red blood cell count: OR 7.65, 95% CI 3.7-15.9, P = 0.001) and high 6-MMP/6-TGN ratios (>24: OR 5.35, 95% CI -3.43 to 8.43, P = 0.001).

CONCLUSIONS

We observed significant associations between 6-MMP/6-TGN ratios and clinical response, and risk of hepatotoxicity. Our results suggest that determination of thiopurine metabolite ratios is a valuable tool for identification of patients at increased risk of therapeutic failure and hepatotoxicity.

Transition of the patient with IBD from pediatric to adult care-an assessment of current evidence

Inflammatory bowel disease is a chronic disease of remitting and relapsing nature that is increasingly diagnosed in childhood or adolescence. The importance of the transition from pediatric to adult health care is increasingly recognized, yet the preparation of patient and family before transfer and early subsequent care in the adult health care environment can be variable and challenging. Pediatric providers need to start early and prepare patients in a stepwise fashion. However, patients may not have mastered all the steps before transfer or may regress to earlier behaviors during stress. Thus, adult providers will need to understand how to maintain and finish the transition process. This is an updated literature review of the transition process in inflammatory bowel disease, which focuses on the practical ways that both pediatric and adult health care providers can optimize care.