Medication level variability index predicts rejection, possibly due to nonadherence, in adult liver transplant recipients

Influence of Tacrolimus Intrapatient Variability on Allograft Rejection Frequency and Survival Following Liver Transplantation

BACKGROUND

Tacrolimus is the primary calcineurin inhibitor used in immunosuppressive regimens to prevent allograft rejection (AR) after organ transplantation. Recent studies have linked intrapatient variability (IPV) of tacrolimus with AR occurrence and reduced survival, especially in kidney transplant recipients. However, limited data are available on the impact of tacrolimus IPV on adverse outcomes after liver transplantation (LT).

AIMS

The aim of this study was to assess the association between tacrolimus IPV using various methodologies with acute AR and long-term patient survival after LT.

METHODS

All patients who underwent LT from January 2010 to July 2021 were retrospectively evaluated. Tacrolimus IPV was calculated for each patient using the mean and SD, mean absolute deviation (MAD), coefficient of variation (CV), and time in therapeutic range (TTR). These measures were then compared with AR within the first 24 months after LT and to long-term survival.

RESULTS

Out of 234 patients, 32 (13.7%) developed AR and 183 (78.2%) survived, with a mean follow-up of 101 ± 43 months. Tacrolimus IPV, assessed by mean, SD, MAD, and CV, was 8.3 ± 2.1, 2.7 ± 1.3, 32.0% ± 11.7%, and 39.4% ± 15.4%, respectively. There was no statistically significant correlation between Tacrolimus IPV and AR or survival post-LT.

CONCLUSIONS

In a large cohort of patients from diverse racial backgrounds, tacrolimus IPV was not associated with clinically relevant outcomes such as AR and survival after LT.

Alcoholic Etiology, Severity of Liver Disease, and Post-Transplant Adherence Are Correlated with Worse Stanford Integrated Psychosocial Assessment for Transplantation (SIPAT) in Liver Transplant Candidates

Introduction: Psychosocial pre-transplant evaluation in patients undergoing liver transplantation (LT) could help identify those patients at higher risk of pharmacological non-adherence, organ rejection, and mortality. The Stanford Integrated Psychosocial Assessment for Transplantation (SIPAT) is a validated tool for assessing LT candidates' psychosocial well-being. Data on the ability of the SIPAT evaluation to predict post-transplant outcomes are sparse. Material and Methods: clinical and psychosocial data from a sample of 134 candidates for LT were analyzed. Moreover, the association between pre-transplant psychosocial evaluation and post-transplant clinical outcomes, including organ rejection, mortality, and immunosuppressant drug adherence, was calculated. Results: At the pre-transplant evaluation, patients who showed high SIPAT scores (77, 57%) also had more liver disease assessed by model for end-stage liver disease (MELD; F = 5.04; p < 0.05), alcoholic etiology (F = 35.80; p < 0.001), encephalopathy (F = 5.02; p < 0.05), and portal hypertension (F = 7.45; p < 0.01). Of the 51 transplant patients, those who had a high pre-transplant SIPAT score showed lower post-transplant immunosuppressive adherence, linked to more frequent immunological events. Conclusions: Patients with an alcoholic etiology of liver disease and more severe liver dysfunction are likelier to not adhere to medical prescriptions following transplantation. Current data suggests that this specific group of patients could benefit from early psychological pre-habilitation before undergoing liver transplantation.

The use of once-daily LCP-Tacrolimus with adolescent and young adult solid organ transplant recipients

BACKGROUND

Adolescent and young adult (AYA) solid organ transplant (SOT) recipients experience increased rates of rejection and graft loss surrounding the time of health care transition, in part due to poor medication adherence. This study aims to examine the impact of a once-daily formulation of tacrolimus, LCP-tacrolimus (LCPT), on medication adherence for AYA SOT patients.

METHODS

A retrospective descriptive analysis was performed for all patients who underwent SOT and were prescribed LCPT after the age of 12 at our single-center pediatric hospital. Medication adherence was assessed via provider documentation and the medication level variability index (MLVI).

RESULTS

Twenty-nine patients were prescribed LCPT as part of their immunosuppression regimen. Twenty patients were converted to LCPT from immediate-acting (IR) tacrolimus; six patients were initiated immediately following transplant, and three patients were unable to receive LCPT due to insurance denial. There was a numeric improvement in medication adherence for converted patients when measured by provider assessment (45.0% vs. 68.4%, p = .140) and MLVI (40.0% vs. 71.4%, p = .276), though these did not reach statistical significance. There were no differences in episodes of rejection or adverse effects. LCPT prescription was not associated with decreased medication burden, and two patients transitioned back to IR tacrolimus due to increased cost.

CONCLUSIONS

LCPT use did not significantly improve patient adherence; however, it resulted in numerically higher perceived and measured adherence rates. LCPT appears to be safe and effective in the management of SOT recipients; however, it may not affect pill burden and may result in a higher financial burden. Use may be considered for a select group of AYA SOT recipients.

UK guideline on the transition and management of childhood liver diseases in adulthood

INTRODUCTION

Improved outcomes of liver disease in childhood and young adulthood have resulted in an increasing number of young adults (YA) entering adult liver services. The adult hepatologist therefore requires a working knowledge in diseases that arise almost exclusively in children and their complications in adulthood.

AIMS

To provide adult hepatologists with succinct guidelines on aspects of transitional care in YA relevant to key disease aetiologies encountered in clinical practice.

METHODS

A systematic literature search was undertaken using the Pubmed, Medline, Web of Knowledge and Cochrane database from 1980 to 2023. MeSH search terms relating to liver diseases ('cholestatic liver diseases', 'biliary atresia', 'metabolic', 'paediatric liver diseases', 'autoimmune liver diseases'), transition to adult care ('transition services', 'young adult services') and adolescent care were used. The quality of evidence and the grading of recommendations were appraised using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system.

RESULTS

These guidelines deal with the transition of YA and address key aetiologies for the adult hepatologist under the following headings: (1) Models and provision of care; (2) screening and management of mental health disorders; (3) aetiologies; (4) timing and role of liver transplantation; and (5) sexual health and fertility.

CONCLUSIONS

These are the first nationally developed guidelines on the transition and management of childhood liver diseases in adulthood. They provide a framework upon which to base clinical care, which we envisage will lead to improved outcomes for YA with chronic liver disease.

High intra-patient variability of tacrolimus within post-operative 1 month predicted worse 1-year outcomes in pediatric liver transplant recipients

BACKGROUND

The pharmacokinetics of tacrolimus (TAC) show high intra-patient variability (IPV), which is associated with poor long-term outcomes following adult liver transplantation (LT). However, this relationship remains to be confirmed in pediatric liver transplant (PLT) recipients. The present study aimed to investigate the association between TAC IPV and grafts or patient outcomes after pediatric liver transplantion.

METHODS

This retrospective study included 848 PLT recipients (including infants) between January, 2016, and June, 2021. The IPV of TAC concentrations was estimated by calculating the coefficient of variation (CV) of trough concentrations in whole blood within 1 month after transplantation. Patients were categorized into two groups, low IPV (CV < 45%) and high IPV (CV ≥ 45%), based on the third quartile of the CV distribution.

RESULTS

A total of 848 patients were included in our study. The low CV group included 614 patients, with a mean TAC trough concentration of 8.59 ± 1.65 ng/ml and a median CV of 32.37%. In contrast, the high CV group included 214 patients, the mean TAC trough concentration and median CV were 8.81 ± 2.00 ng/ml and 54.88%, respectively. The median hospital duration was significantly higher in the high CV group (22 days vs. 20 days, P = 0.01). Univariate analysis was performed to evaluate the significant differences in 1-year recipient survival (P = 0.041) and 1-year graft survival (P = 0.005) between the high- and low-CV groups. Moreover, high CV (HR 2.316, 95%CI 1.026-5.231, P = 0.043) and persistent EBV viremia (HR 13.165, 95%CI 3.090-56.081, P < 0.001) were identified as independent risk factors for 1- year mortality after PLT.

CONCLUSIONS

PLT recipients with high TAC trough concentration of CV in the first month were associated with poor 1-year outcomes. This CV calculation provides a valuable strategy to monitor TAC exposure.

Demographic Factors, Medication Adherence, and Post-transplant Health Outcomes: A Longitudinal Multilevel Modeling Approach

Few studies in pediatric solid organ transplantation have examined non-adherence to immunosuppressive medication over time and its associations with demographic factors and post-transplant outcomes including late acute rejection and hospitalizations. We examined longitudinal variation in patient Medication Level Variability Index (MLVI) adherence data from pediatric kidney, liver, and heart transplant recipients. Patient and administrative data from the United Network for Organ Sharing were linked with electronic health records and MLVI values for 332 patients. Multilevel mediation modeling indicated comparatively more variation in MLVI values between patients than within patients, longitudinally, over 10 years post transplant. MLVI values significantly predicted late acute rejection and hospitalization. MLVI partially mediated patient factors and post-transplant outcomes for patient age indicating adolescents may benefit most from intervention efforts. Results demonstrate the importance of longitudinal assessment of adherence and differences among patients. Efforts to promote medication adherence should be adapted to high-risk patients to increase likelihood of adherence.

Changes over time in self-efficacy and the allocation of responsibility for health management tasks in pediatric liver transplant recipients: Targets to improve the transition process

BACKGROUND

The process of transition to adult-based care encompasses a critical period in the life of an adolescent and young adult living with a chronic illness and one that comes with an increase in the risk of poor health outcomes. As yet, there is a dearth of empirical data to help optimize this process to ensure the best long-term outcome.

METHODS

This study used a principal components analysis to determine specific constructs measured by a revised version of the transition readiness survey used in our clinic. We investigated changes in these constructs over time. We further investigated the relationship between the change in these constructs over time spent in a focused transition program with adherence.

RESULTS

The primary component underlying our transition readiness survey for patients and parents represented self-efficacy. Time spent in the transition program was an independent predictor of change in self-efficacy (rho 0.299, p = .015); however, the magnitude of that change had no relationship to adherence. Change in parent-proxy self-efficacy was found to have a statistically significant relationship with tacrolimus standard deviation (rho -0.301, p = .026). There was disagreement identified between patient and parent responses on the survey. Neither change in patient nor parent reports of self-efficacy was found to have a relationship with post-transfer adherence.

CONCLUSIONS

This study reaches the novel conclusion that self-efficacy and parent-proxy self-efficacy are dynamic concepts that change over time spent in a focused transition program. The patient-parent disagreement and the relationship between parent-proxy self-efficacy and adherence stress the importance of involving parents/guardians in the transition process as well.

The improving Medication Adherence in Adolescents and young adults following Liver Transplantation (iMALT) multisite trial: Design and trial implementation considerations

BACKGROUND/AIMS

Medication non-adherence is a leading cause of transplant rejection, organ loss, and death; yet no rigorous controlled study to date has shown compelling clinical benefits from an adherence-improving intervention. Non-adherent patients are less likely to participate in trials, and therefore, most studies enroll a majority of adherent patients who do not stand to benefit from the intervention, as they do not have the condition (non-adherence) under investigation. The improving Medication Adherence in adolescent Liver Transplant recipients trial specifically targets non-adherent patients to investigate whether a remote intervention to improve adherence results in reduced incidence of biopsy-confirmed rejection.

METHODS

Improving Medication Adherence in adolescent Liver Transplant is a randomized single-blind controlled multisite, multinational National Institutes of Health-funded trial involving 13 pediatric transplant centers in the United States and Canada. An innovative, objective adherence biomarker-the Medication Level Variability Index, which is the standard deviation of a series of medication blood levels for each patient, is used to identify non-adherent patients at risk for rejection. The index is computed using electronic health record information for all potentially eligible patients based on repeated reviews of the entire clinic's roster. Identified patients, after consent, are randomized to intervention versus control (treatment as usual) arms. The remote intervention is delivered for 2 years by trained interventionists who reside in various locations in the United States. The primary outcome is the incidence of biopsy-confirmed acute cellular rejection, as confirmed by a majority vote of three pathologists who are masked to the study allocation and clinical information.

DISCUSSION

Improving Medication Adherence in adolescent Liver Transplant includes several innovative design elements. The use of a validated, objective adherence index to survey a large cohort of transplant recipients allows the teams to avoid bias inherent in both convenience sampling and referral-based recruitment and enroll only patients whose computed index indicates substantially increased risk of rejection. The remote intervention paradigm helps to engage patients who are by definition hard to engage. The use of an objective, masked medical (rather than behavioral) outcome measure reduces the likelihood of biases related to clinical information and ensures broad acceptance by the field. Finally, monitoring for potential adverse events related to increased medication exposure due to the adherence intervention acknowledges that a successful intervention (increasing adherence) could have detrimental side effects via increased exposure to and potential toxicity of the medication. Such monitoring is almost never attempted in clinical trials evaluating adherence interventions.

Patient randomised controlled trial of technology enabled strategies to promote treatment adherence in liver transplantation: rationale and design of the TEST trial

BACKGROUND AND AIMS

Liver transplantation is a life-saving procedure for end-stage liver disease. However, post-transplant medication regimens are complex and non-adherence is common. Post-transplant medication non-adherence is associated with graft rejection, which can have long-term adverse consequences. Transplant centres are equipped with clinical staff that monitor patients post-transplant; however, digital health tools and proactive immunosuppression adherence monitoring has potential to improve outcomes.

METHODS AND ANALYSIS

This is a patient-randomised prospective clinical trial at three transplant centres in the Northeast, Midwest and South to investigate the effects of a remotely administered adherence programme compared with usual care. The programme monitors potential non-adherence largely levering text message prompts and phenotypes the nature of the non-adhere as cognitive, psychological, medical, social or economic. Additional reminders for medications, clinical appointments and routine self-management support are incorporated to promote adherence to the entire medical regimen. The primary study outcome is medication adherence via 24-hour recall; secondary outcomes include additional medication adherence (ASK-12 self-reported scale, regimen knowledge scales, tacrolimus values), quality of life, functional health status and clinical outcomes (eg, days hospitalised). Study implementation, acceptability, feasibility, costs and potential cost-effectiveness will also be evaluated.

ETHICS AND DISSEMINATION

The University of Pennsylvania Review Board has approved the study as the single IRB of record (protocol # 849575, V.1.4). Results will be published in peer-reviewed journals and summaries will be provided to study funders.

TRIAL REGISTRATION NUMBER

NCT05260268.

Impact of tacrolimus intra-patient variability in adverse outcomes after organ transplantation

Tacrolimus (Tac) is currently the most common calcineurin-inhibitor employed in solid organ transplantation. High intra-patient variability (IPV) of Tac (Tac IPV) has been associated with an increased risk of immune-mediated rejection and poor outcomes after kidney transplantation. Few data are available concerning the impact of high Tac IPV in non-kidney transplants. However, even in kidney transplantation, there is still a controversy whether high Tac IPV is indeed detrimental in respect to graft and/or patient survival. This may be due to different methods employed to evaluate IPV and distinct time frames adopted to assess graft and patient survival in those reports published up to now in the literature. Little is also known about the influence of high Tac IPV in the development of other untoward adverse events, update of the current knowledge regarding the impact of Tac IPV in different outcomes following kidney, liver, heart, lung, and pancreas tran splantation to better evaluate its use in clinical practice.

Randomized pilot trial of praise text messages to improve medication adherence among adolescents and young adults with liver transplants

BACKGROUND

AYA who have undergone liver transplantations often struggle to adhere to their post-transplant immunosuppressant medications, which can lead to serious health complications. The objective of this pilot study is to examine the acceptability and feasibility of a brief mobile health (mHealth) intervention and its impact on medication adherence among AYA liver transplant recipients.

METHODS

Thirty-five AYAs (13-21 years old) were randomized to either (1) receive praise text messages whenever laboratory results indicated immunosuppressant medications within the expected range or (2) usual care. Motivation for adherence and adherence were assessed via self-report, and a MLVI was calculated based on values abstracted from the electronic health record.

RESULTS

Multilevel, multivariate models showed significant associations between group assignment and some self-reported motivation and adherence outcomes but not MLVI. Specifically, AYA receiving the praise text messages were significantly more likely to report taking their prescribed doses (OR = 2.49, p = .03), taking their medicine according to the directions (OR = 2.39, p = .04), and being highly confident in taking their medication (OR = 2.46, p = .04), compared with the usual services group. Qualitative responses indicated praise texts were mostly helpful but could be improved.

CONCLUSIONS

The results suggest texting patients about positive health indicators was acceptable and, with refinement, might promote AYA illness self-management.

MENTAL DISORDERS AND LIVER TRANSPLANTATION: A 2-YEAR COHORT STUDY

BACKGROUND

Psychosocial assessment is a key component in evaluation for liver transplantation and may affect survival rates and outcomes.

OBJECTIVE

The primary aim of this study was to investigate the impact of previous mental disorders and impulsivity on the 2-year surviving rate after liver transplantation.

METHODS

We performed a prospective cohort study assessing end-stage liver disease individuals with and without psychiatric comorbidities for 2 years post-transplant. Psychiatric diagnosis was carried out through Mini-Plus 5.0.0 and impulsivity by using Barratt Impulsiveness Scale in the pre-transplant phase. We followed patient's status for 2 years after transplantation. The main outcome was death. We used a logistic regression to evaluate the association of psychiatric comorbidities with death and performed a survival analysis with Kaplan-Meier and Cox regression models.

RESULTS

Between June 2010 and July 2014, 93 out of 191 transplant candidates received transplants. From the 93 transplant patients, 21 had psychiatric comorbidities and 72 had not. 25 patients died during the study. The presence of psychiatric comorbidities (P=0.353) and high impulsivity (P=0.272) were not associated to 2-year post transplant death.

CONCLUSION

This study found no evidence that the presence of mental disorders and impulsivity worsened prognosis in post-liver transplantation.

Directly observed therapy to promote medication adherence in adolescent heart transplant recipients

PURPOSE

HT recipients experience high levels of medication non-adherence during adolescence. This pilot study examined the acceptability and feasibility of an asynchronous DOT mHealth application among adolescent HT recipients. The app facilitates tracking of patients' dose-by-dose adherence and enables transplant team members to engage patients. The DOT application allows patients to self-record videos while taking their medication and submit for review. Transplant staff review the videos and communicate with patients to engage and encourage medication adherence.

METHODS

Ten adolescent HT recipients with poor adherence were enrolled into a single-group, 12-week pilot study examining the impact of DOT on adherence. Secondary outcomes included self-report measures from patients and parents concerning HRQOL and adherence barriers. Long-term health outcomes assessed included AR and hospitalization 6 months following DOT.

FINDINGS

Among 14 adolescent HT patients approached, 10 initiated the DOT intervention. Of these, 8 completed the 12-week intervention. Patients and caregivers reported high perceptions of acceptability and accessibility. Patients submitted 90.1% of possible videos demonstrating medication doses taken. MLVI values for the 10 patients initiating DOT decreased from 6 months prior to the intervention (2.86 ± 1.83) to 6 months following their involvement (2.08 ± 0.87) representing a 21.7% decrease in non-adherence, though not statistically significant given the small sample size.

CONCLUSIONS

Result of this pilot study provides promising insights regarding the feasibility, acceptability, and potential impact of DOT for adolescent HT recipients. Further randomized studies are required to confirm these observations.

Initial attendance and retention in adult healthcare as criteria for transition success among organ transplant recipients

BACKGROUND

Adolescent and young adult (AYA) solid organ transplant recipients experience worsening medical outcomes during transition to adult healthcare. Current understanding and definitions of transition success emphasize first initiation of appointment attendance in adult healthcare; however, declines in attendance over time after transfer remain possible, particularly as AYAs are further removed from their pediatric provider and assume greater independence in their care.

METHODS

The current study assessed health-care utilization, medical outcomes, and transition success among 49 AYA heart, kidney, or liver recipients recently transferred to adult healthcare. Differences in outcomes were examined along two transition success criteria: (1) initial engagement in adult healthcare within 6 or 12 months of last pediatric appointment and (2) retention in adult healthcare over 3 years following last pediatric appointment. Growth curve modeling examined change in attendance over time.

RESULTS

Successful retention in adult healthcare was significantly related to more improved clinical outcomes, including decreased number and duration of hospitalizations and greater medication adherence, as compared to initial engagement. Significant declines in appointment attendance over 3 years were noted, and individual differences in declines were not accounted for by age at transfer or time since transplant.

CONCLUSIONS

Findings underscore support for AYAs after transfer, as significant declines in attendance were noted after initiating adult care. Clinical care teams should examine transition success longitudinally to address changes in health-care utilization and medical outcomes. Attention to interventions and administrative support aimed at maintaining or increasing attendance and identifying risk factors and intervention for unsuccessful transition is warranted.

High intrapatient variability of tacrolimus exposure associated with poorer outcomes in liver transplantation

Tacrolimus (TAC) is a dose‐dependent immunosuppressor with considerable intrapatient variability (IPV) in its pharmacokinetics. The aim of this work is to ascertain the association between TAC IPV at 6 months after liver transplantation (LT) and patient outcome. This single‐center cohort study retrospectively analyzed adult patients who underwent transplantation from 2015 to 2019 who survived the first 6 months with a functioning graft. The primary end point was the patient’s probability of death and the secondary outcome was the loss of renal function between month 6 and the last follow‐up. TAC IPV was estimated by calculating the coefficient of variation (CV) of the dose‐corrected concentration (C₀/D) between the third and sixth months post‐LT. Of the 140 patients who underwent LT included in the study, the low‐variability group (C₀/D CV < 27%) comprised 105 patients and the high‐variability group (C₀/D CV ≥ 27%) 35 patients. One‐, 3‐, and 5‐year patient survival rates were 100%, 82%, and 72% in the high‐variability group versus 100%, 97%, and 93% in the low‐variability group, respectively (p = 0.005). Moreover, significant impaired renal function was observed in the high‐variability group at 1 year (69 ± 16 ml/min/1.73 m² vs. 78 ± 16 ml/min/1.73 m², p = 0.004) and at 2 years post‐LT (69 ± 17 ml/min/1.73 m² vs. 77 ± 15 ml/min/1.73 m², p = 0.03). High C₀/D CV 3–6 months remained independently associated with worse survival (hazard ratio = 3.57, 95% CI = 1.32–9.67, p = 0.012) and loss of renal function (odds ratio = 3.47, 95% CI = 1.30–9.20, p = 0.01). Therefore, high IPV between the third and sixth months appears to be an early and independent predictor of patients with poorer liver transplant outcomes.

Early Survivorship After Liver Transplantation: A Qualitative Study Identifying Challenges in Recovery From the Patient and Caregiver Perspective

Survivorship after liver transplantation (LT) is a novel concept providing a holistic view of the arduous recovery experienced after transplantation. We explored components of early survivorship including physical, emotional, and psychological challenges to identify intervention targets for improving the recovery process of LT recipients and caregivers. A total of 20 in-person interviews were conducted among adults 3 to 6 months after LT. Trained qualitative research experts conducted interviews, coded, and analyzed transcripts to identify relevant themes and representative quotes. Early survivorship comprises overcoming (1) physical challenges, with the most challenging experiences involving mobility, driving, dietary modifications, and medication adherence, and (2) emotional and psychological challenges, including new health concerns, financial worries, body image/identity struggles, social isolation, dependency issues, and concerns about never returning to normal. Etiology of liver disease informed survivorship experiences including some patients with hepatocellular carcinoma expressing decisional regret or uncertainty in light of their post-LT experiences. Important topics were identified that framed LT recovery including setting expectations about waitlist experiences, hospital recovery, and ongoing medication requirements. Early survivorship after LT within the first 6 months involves a wide array of physical, emotional, and psychological challenges. Patients and caregivers identified what they wish they had known prior to LT and strategies for recovery, which can inform targeted LT survivorship interventions.

Posttraumatic stress and medication adherence in pediatric transplant recipients

Adolescent transplant recipients may encounter a range of potentially traumatic events (PTEs) pre- and posttransplant, yet little is known about the relationship between posttraumatic stress symptoms (PTSS) and medication adherence in this population. In the present study, adolescent recipients and caregivers completed psychosocial questionnaires at enrollment. Outpatient tacrolimus trough level data were collected over 1 year to calculate the Medication Level Variability Index (MLVI), a measure of medication adherence. Nonadherence (MLVI ≥2) was identified in 34.8% of patients, and most (80.7%) reported ≥1 PTE exposure. Levels of PTSS indicating likely posttraumatic stress disorder (PTSD) were endorsed by 9.2% of patients and 43.7% of caregivers. PTSS and MLVI were significantly correlated in the liver subgroup (r = .30, p = .04). Hierarchical multivariable linear regression analyses revealed overall patient PTSS were significantly associated with QoL (p < .001). PTEs are common in adolescent recipients; a minority may meet criteria for PTSD. PTSS screening to identify nonadherence risk requires further investigation and addressing PTSS may improve QoL. Caregivers appear at greater risk for PTSD and may require their own supports. The study was approved by each participating center's Institutional Review Board.

The Role of Intra-Patient Variability of Tacrolimus Drug Concentrations in Solid Organ Transplantation: A Focus on Liver, Heart, Lung and Pancreas

Tacrolimus, the keystone immunosuppressive drug administered after solid organ transplantation, presents a narrow therapeutic index and wide inter- and intra-patient pharmacokinetic variability (IPV). The latter has been fairly studied in kidney transplantation, where it could impact outcomes. However, literature about other transplanted organ recipients remains inconclusive. This review aimed at summarizing the evidence about the IPV of tacrolimus concentrations outside of the scope of kidney transplantation. First, factors influencing IPV will be presented. Then, the potential of IPV as a biomarker predictive of graft outcomes will be discussed in liver, heart, lung and pancreas transplantation. Lastly, strategies to reduce IPV will be reviewed, with the ultimate objective being ready-to-implement solutions in clinical practice by transplantation professionals.

Impact of intrapatient blood level variability of calcineurin inhibitors on heart transplant outcomes

INTRODUCTION AND OBJECTIVES

Intrapatient blood level variability (IPV) of calcineurin inhibitors has been associated with poor outcomes in solid-organ transplant, but data for heart transplant are scarce. Our purpose was to ascertain the clinical impact of IPV in a multi-institutional cohort of heart transplant recipients.

METHODS

We retrospectively studied patients aged ≥18 years, with a first heart transplant performed between 2000 and 2014 and surviving≥ 1 year. IPV was assessed by the coefficient of variation of trough levels from posttransplant months 4 to 12. A composite of rejection or mortality/graft loss or rejection and all-cause mortality/graft loss between years 1 to 5 posttransplant were analyzed by Cox regression analysis.

RESULTS

The study group consisted of 1581 recipients (median age, 56 years; women, 21%). Cyclosporine immediate-release tacrolimus and prolonged-release tacrolimus were used in 790, 527 and 264 patients, respectively. On multivariable analysis, coefficient of variation> 27.8% showed a nonsignificant trend to association with 5-year rejection-free survival (HR, 1.298; 95%CI, 0.993-1.695; P=.056) and with 5-year mortality (HR, 1.387; 95%CI, 0.979-1.963; P=.065). Association with rejection became significant on analysis of only those patients without rejection episodes during the first year posttransplant (HR, 1.609; 95%CI, 1.129-2.295; P=.011). The tacrolimus-based formulation had less IPV than cyclosporine and better results with less influence of IPV.

CONCLUSIONS

IPV of calcineurin inhibitors is only marginally associated with mid-term outcomes after heart transplant, particularly with the tacrolimus-based immunosuppression, although it could play a role in the most stable recipients.

Inferior outcomes in young adults undergoing liver transplantation - a UK and Ireland cohort study

Graft loss incidence is reported to be inversely related to recipient age. We used a national cohort of liver transplant (LT) recipients from the United Kingdom and Ireland to compare the age-dependent risk of graft failure in different post-transplantation time-periods ('epochs'). A cohort of first-time LT recipients (1995-2016) were identified (11 006). Cox regression was used to estimate hazard ratios (HR) comparing graft loss between age-groups (18-29, 30-39, 40-49, 50-59 and 60-76 years) and graft loss in different post-transplant epochs: 0-90 days, 90 days-2 years and 2-10 years. The risk of graft failure was highest in those transplanted between age 18 and 29 (adjusted HR 1.25, 95% CI: 1.00-1.57, P = 0.04) and in those aged 30-39 (adjusted HR 1.31, 95% CI: 1.11-1.55, P = 0.02). Graft failure in those under the age of 40 was similar in the first 90 days but worse 2-10 years' post-LT (18-29 years HR 1.36, 95% CI: 0.96-1.93, P < 0.001). Graft failure because of chronic rejection (CR) was more common in recipients aged 18-29 (P < 0.001). Adults transplanted between age 18 and 39 are at risk of late graft loss. CR is a concern for young adults (18-29 years). Our data highlights the need for specialist young adult services within adult healthcare.

Impact of tacrolimus variability on pediatric heart transplant outcomes

BACKGROUND

Tacrolimus is a narrow therapeutic index drug, requiring consistent levels to maximize transplant success while reducing adverse effects. Elevated tacrolimus level variability (ETLV) is associated with poor outcomes in both pediatric and adult solid organ transplant recipients. We sought to describe the prevalence of ETLV and identify associations with patient-specific factors and poor outcomes.

METHODS

Tacrolimus levels were evaluated from 118 patients at our single center. As a marker of variability, standard deviations (SD) were calculated for each patient from their entire tacrolimus level data set (global SD), and 1-2 years and 1-5 years post-HT (prediction window SDs). SD ≥3 denoted ETLV.

RESULTS

There was large variability in tacrolimus levels (median global SD 3.1; IQR 2.3, 4; SD ≥3, n = 64, 54%). Patients with elevated SD (≥3) vs lower SD (<3) were more likely to have poor outcomes including rejection (73% vs 46%), cardiac allograft vasculopathy (CAV, 22% vs 9%), and death (20% vs 6%). The prediction window analysis noted ETLV was associated with a 40% greater risk of CAV, re-HT, or death (p = .024) and increasing age at transplantation was associated with a 12% increase in the risk of rejection (p = <.001) and a 19% increase in the risk of a composite event (p = .021).

CONCLUSION

ETLV is prevalent in the pediatric HT population with increased frequency of poor outcomes in those with SD ≥3. ETLV is an easily accessible marker with which to risk-stratify patients.

Remote intervention engagement and outcomes in the Clinical Trials in Organ Transplantation in Children consortium multisite trial

Remote interventions are increasingly used in transplant medicine but have rarely been rigorously evaluated. We investigated a remote intervention targeting immunosuppressant management in pediatric lung transplant recipients. Patients were recruited from a larger multisite trial if they had a Medication Level Variability Index (MLVI) ≥2.0, indicating worrisome tacrolimus level fluctuation. The manualized intervention included three weekly phone calls and regular follow-up calls. A comparison group included patients who met enrollment criteria after the subprotocol ended. Outcomes were defined before the intent-to-treat analysis. Feasibility was defined as ≥50% of participants completing the weekly calls. MLVI was compared pre- and 180 days postenrollment and between intervention and comparison groups. Of 18 eligible patients, 15 enrolled. Seven additional patients served as the comparison. Seventy-five percent of participants completed ≥3 weekly calls; average time on protocol was 257.7 days. Average intervention group MLVI was significantly lower (indicating improved blood level stability) at 180 days postenrollment (2.9 ± 1.29) compared with pre-enrollment (4.6 ± 2.10), p = .02. At 180 days, MLVI decreased by 1.6 points in the intervention group but increased by 0.6 in the comparison group (p = .054). Participants successfully engaged in a long-term remote intervention, and their medication blood levels stabilized. NCT02266888.

No Apparent Influence of Nonadherence on Tacrolimus Intrapatient Variability in Stable Kidney Transplant Recipients

BACKGROUND

High intrapatient variability (IPV) in tacrolimus exposure has been associated with an increased risk of graft rejection and graft loss. It has been suggested that medication nonadherence has high impact on IPV. The objective of this study is to assess the relationship between tacrolimus IPV and medication nonadherence in stable kidney transplant recipients.

METHODS

This study was conducted within the Reducing Renal Function Deterioration trial (Netherlands Trial Register: NTR7256), which included stable kidney transplant recipients. Nonadherence was assessed quantitatively by electronic monitoring (EM) and qualitatively using the composite adherence score (CAS) consisting of patient self-reporting (Immunosuppressant Therapy Adherence Scale), a physician report, and the tacrolimus trough concentrations (C0). IPV in tacrolimus C0 and area under the concentration-time curves (AUCs) was evaluated at 5 and 3 sampling instances, respectively.

RESULTS

Data of 64 kidney transplant recipients (43 males, 21 females; mean age 53.6 years), mean time post-transplantation 5.4 years, were collected. Mean missed tacrolimus intake was 7% (0.3%-13.4%) based on EM, missing one intake every 2 weeks. Based on the CAS, 68.9% of the patients were categorized as nonadherent. The mean IPV was 17.9% (4.4%-65.3%) and 20.2% (2.5%-51.6%) for tacrolimus C0 and AUCs, respectively. The nonadherence data displayed a nonparametric distribution, with nonadherence scores mostly in the lower ranges. There was no significant difference in the mean IPV between adherent and nonadherent patients. There were no differences in EM, CAS, physician report, or time-in-therapeutic range, but patients with a low AUC IPV showed a slightly higher Immunosuppressant Therapy Adherence Scale score than those with a high AUC IPV (P = 0.035).

CONCLUSIONS

There was no apparent relationship between IPV and nonadherence in this motivated kidney transplant recipient population, with one missed tacrolimus dose every 2 weeks.

Long-term, Prolonged-release Tacrolimus-based Immunosuppression in De Novo Liver Transplant Recipients: 5-year Prospective Follow-up of Patients in the DIAMOND Study

Background

Immunosuppression with calcineurin inhibitors (CNIs) is reportedly associated with risk of renal impairment in liver transplant recipients. It is believed that this can be mitigated by decreasing initial exposure to CNIs or delaying CNI introduction until 3-4 d posttransplantation. The ADVAGRAF studied in combination with mycophenolate mofetil and basiliximab in liver transplantation (DIAMOND) trial evaluated different administration strategies for prolonged-release tacrolimus (PR-T).

Methods

DIAMOND was a 24-wk, open-label, phase 3b trial in de novo liver transplant recipients randomized to: PR-T 0.2 mg/kg/d (Arm 1); PR-T 0.15-0.175 mg/kg/d plus basiliximab (Arm 2); or PR-T 0.2 mg/kg/d delayed until day 5 posttransplant plus basiliximab (Arm 3). In a 5-y follow-up, patients were maintained on an immunosuppressive regimen according to standard clinical practice (NCT02057484). Primary endpoint: graft survival (Kaplan-Meier analysis).

Results

Follow-up study included 856 patients. Overall graft survival was 84.6% and 73.5% at 1 and 5 y post transplant, respectively. Five-year rates for Arms 1, 2, and 3 were 74.7%, 71.5%, and 74.5%, respectively. At 5 y, death-censored graft survival in the entire cohort was 74.7%. Overall graft survival in patients remaining on PR-T for ≥30 d was 79.1%. Graft survival in patients who remained on PR-T at 5 y was 87.3%. Patient survival was 86.6% at 1 y and 76.3% at 5 y, with survival rates similar in the 3 treatment arms at 5 y. Estimated glomerular filtration rate at the end of the 24-wk initial study and 5 y posttransplant was 62.1 and 61.5 mL/min/1.73 m², respectively, and was similar between the 3 treatment arms at 5 y. Overall, 18 (2.9%) patients had ≥1 adverse drug reaction, considered possibly related to PR-T in 6 patients.

Conclusions

In the DIAMOND study patient cohort, renal function, graft survival, and patient survival were similar between treatment arms at 5 y posttransplant.

A multidisciplinary approach to improving transition readiness in pediatric liver transplant recipients

The Six Core Elements of Transition have been advocated to guide transition, but little is published about their use with liver transplant patients. We started a liver transplant transition program in August 2015 using quality improvement (QI) methods and by linking the Six Core Elements of Transition to process measures. Eligible patients completed baseline transition readiness assessments (Readiness for Transition Questionnaire, RTQ), interviews with a psychologist, received focused education, and completed follow-up RTQs before transfer to adult care. Our QI goal was to improve RTQ scores by 20% prior to transfer to adult care. We also assessed continuity of care, tacrolimus levels, rejection, and retransplantation as balancing measures. Of the 24 patients who completed the transition program and were transferred to adult care, RTQ scores were available for 11 patients. Overall RTQ scores improved from 23.7 to 30.5 (+28.7%, P = .009) prior to transfer. Nearly two-thirds (63%) of patients were seen by adult transplant hepatology within 6 months, and one patient was lost to follow-up after the first adult visit. Tacrolimus-level standard deviations were <2.0 in 45% of patients in pediatric care and 72% of patients in adult care. Three patients had undergone immunosuppression withdrawal in pediatric care, with one restarted on immunosuppression prior to transfer to adult care due to late acute rejection. The Six Core Elements of Transition can be translated into patient- and system-level transition milestones to serve as potential quality metrics in the implementation of transition programs.

Association Between Neighborhood-level Socioeconomic Deprivation and the Medication Level Variability Index for Children Following Liver Transplantation

BACKGROUND

Neighborhood socioeconomic deprivation is associated with adverse health outcomes. We sought to determine if neighborhood socioeconomic deprivation was associated with adherence to immunosuppressive medications after liver transplantation.

METHODS

We conducted a secondary analysis of a multicenter, prospective cohort of children enrolled in the medication adherence in children who had a liver transplant study (enrollment 2010-2013). Participants (N = 271) received a liver transplant ≥1 year before enrollment and were subsequently treated with tacrolimus. The primary exposure, connected to geocoded participant home addresses, was a neighborhood socioeconomic deprivation index (range 0-1, higher indicates more deprivation). The primary outcome was the medication level variability index (MLVI), a surrogate measure of adherence to immunosuppression in pediatric liver transplant recipients. Higher MLVI indicates worse adherence behavior; values ≥2.5 are predictive of late allograft rejection.

RESULTS

There was a 5% increase in MLVI for each 0.1 increase in deprivation index (95% confidence interval, -1% to 11%; P = 0.08). Roughly 24% of participants from the most deprived quartile had an MLVI ≥2.5 compared with 12% in the remaining 3 quartiles (P = 0.018). Black children were more likely to have high MLVI even after adjusting for deprivation (adjusted odds ratio 4.0 95% confidence interval, 1.7-10.6).

CONCLUSIONS

This is the first study to evaluate associations between neighborhood socioeconomic deprivation and an objective surrogate measure of medication adherence in children posttransplant. These findings suggest that neighborhood context may be an important consideration when assessing adherence. Differential rates of medication adherence may partly explain links between neighborhood factors and adverse health outcomes following pediatric liver transplantation.

Tacrolimus intrapatient variability in solid organ transplantation: A multiorgan perspective

BACKGROUND

Tacrolimus therapy in solid organ transplant (SOT) recipients is challenging due to its narrow therapeutic window and pharmacokinetic variability both between patients and within a single patient. Intrapatient variability (IPV) of tacrolimus trough concentrations has become a novel marker of interest for predicting transplant outcomes. The purpose of this review is to evaluate the association of tacrolimus IPV with graft and patient outcomes and identify interventions to improve IPV in SOT recipients.

METHODS

A systematic review of the literature was performed using PubMed and Embase from database inception to September 20, 2020. Studies were eligible only if they evaluated an association between tacrolimus IPV and transplant outcomes. Both pediatric and adult studies were included. Measures of variability were limited to standard deviation, coefficient of variation, and time in therapeutic range.

RESULTS

Forty-four studies met the inclusion criteria. Studies were published between 2008 and 2020 and were observational in nature. Majority of data were published in adult kidney transplant recipients and identified an association with rejection, de novo donor specific antibody (dnDSA) formation, graft loss, and patient survival. Evaluation of IPV-directed interventions was limited to small preliminary studies.

CONCLUSIONS

High tacrolimus IPV has been associated with poor outcomes including acute rejection, dnDSA formation, graft loss, and patient mortality in SOT recipients. Future research should prospectively explore IPV-directed interventions to improve transplant outcomes.

The Utility of a Pre-Transplant Psychosocial Evaluation in Predicting Post-Liver Transplant Outcomes

BACKGROUND

There is insufficient evidence about the ability of pretransplant psychosocial evaluations to predict posttransplant outcomes. While standardized assessments were developed to increase predictive validity, it is unclear whether the risk scores they yield predict outcomes. We investigated if the Stanford Integrated Psychosocial Assessment for Transplantation (SIPAT), a scaling approach to those assessments, would have been a superior predictor than the standard psychosocial evaluation.

METHODS

In this retrospective study, medical records of 182 adult liver transplant recipients who were at least 1 year posttransplant and prescribed tacrolimus for immunosuppression were analyzed. Regression analyses predicted outcomes of interest, including immunosuppressant nonadherence and biopsy-proven rejection, obtained 1-year posttransplant to time of data collection. Nonadherence was determined using the medication level variability index (MLVI).

RESULTS

Approximately 49% of patients had MLVI > 2.5, suggestive of nonadherence, and 15% experienced rejection. SIPAT total score did not predict adherence either using the continuous (P = .70), or dichotimized score, above or below > 2.5 (P = .14), or rejection (P = 0.87). Using a SIPAT threshold (total score > 69) did not predict adherence (p = .16) nor was a superior predictor of the continuous adherence score (P = .45), MLVI > 2.5 (P = .42), or rejection (P = 0.49), than the standard evaluation.

CONCLUSION

Our findings suggest that the SIPAT is unable to predict 2 of the most important outcomes in this population, immunosuppressant adherence and rejection. Research efforts should attempt to evaluate the best manner to use psychosocial evaluations.

Medication non-adherence among liver transplant recipients

PURPOSE OF REVIEW

We provide an overview of the recent evidence on the prevalence, risk factors, and consequences of medication non-adherence (NA) in liver transplant (LT) recipients.

RECENT FINDINGS

NA in LT is associated with socio-demographic and medication-related factors, low social support, and poor health literacy. Patient-reported adherence is one of the most common methods to measure NA using validated assessments; immunosuppression (IS) drug levels and electronic monitoring may also be used. Simplification of IS regimens such as the conversion from twice daily to once daily has been shown to be safe, effective, and improves adherence. Relatively few studies have prospectively investigated NA predictors or interventions to reduce NA in LT.

SUMMARY

Medication non-adherence is a multi-faceted issue that is common among LT recipients and associated with adverse outcomes. NA in LT recipients warrants further study as only a few interventions have been published focused on reducing NA in LT.

Variation in Tacrolimus Trough Concentrations in Liver Transplant Patients Undergoing Endoscopic Retrograde Cholangiopancreatography: A Retrospective, Observational Study

Objective

High variabilities in tacrolimus (TAC) exposure are still problems that confuse physicians. TAC trough levels (TAC C_min) fluctuated considerably after endoscopic retrograde cholangiopancreatography (ERCP) treatment in several liver transplant (LT) patients. We aimed to investigate the variation regularity of TAC C_min post-ERCP and related factors.

Methods

This study was a retrospective, observational study conducted at the First Affiliated Hospital of Zhejiang University in China. From October 2017 to January 2019, 26 LT patients that received ERCP were included (73 TAC C_min measures). The absolute difference and the variation extent in TAC C_min pre- and post-ERCP were analyzed. Patients were divided into mild and obvious variation groups, and the differences were compared.

Results

The TAC C_min in LT patients significantly increased in the first three days post-ERCP (p<0.05) and increased by more than 20% in 18 out of 26 (69.2%) patients. The mean extent of variation in TAC C_min was 45.1% (95% confidence interval [CI]: 28.3–81.3%) and 31.4% (95% CI: 9.7–53.1%) on days 1 and 3 post-ERCP, respectively. The increasing TAC C_min gradually returned to baseline within a week (p>0.05). The daily TAC dose and total bile acid (TBA) level were significantly higher (p<0.05) in patients with obvious variation in TAC C_min. The differences in other demographics, clinical characteristics, variation in laboratory data, and serum amylase levels between the two groups were not significant.

Conclusion

The TAC C_min significantly increased in LT patients during the first three days after ERCP, and the level returned to baseline within a week. The daily TAC dose and TBA levels may be related to this increase. Frequent drug concentration monitoring should be executed in the early phase post-ERCP, especially in patients with related factors.

High Intrapatient Variability in Tacrolimus Exposure Is Not Associated With Immune-mediated Graft Injury After Liver Transplantation

BACKGROUND

A high intrapatient variability (IPV) in tacrolimus exposure is associated with impaired long-term clinical outcome after kidney transplantation. It remains to be determined if this is equally detrimental for liver transplant recipients. The objective of this study was to investigate the association between IPV in tacrolimus exposure and immune-mediated graft injury after liver transplantation.

METHODS

For 326 liver transplant recipients, transplanted between 2000 and 2015, tacrolimus IPV was calculated from at least 5 tacrolimus trough samples obtained between months 6 and 18 after liver transplantation and expressed as the coefficient of variation. Primary composite endpoint consisted of immune-mediated graft injury (chronic rejection, biopsy proven, and suspected late acute rejection) after month 6. Secondary outcomes were the association between tacrolimus IPV on (1) loss of renal function per year of follow-up and (2) cytomegalovirus viremia after month 6.

RESULTS

Of the 326 included liver transplant recipients, 70 patients (21.5%) reached the primary endpoint. Median tacrolimus coefficient of variation was 28%. There was no significant difference in reaching the primary composite endpoint between the low- and high-IPV groups (P = 0.068). Model for End-Stage Liver Disease score pretransplantation and the number of acute rejections were identified as independent predictors for immune-mediated graft injury (P = 0.049 and 0.016). A higher IPV in combination with a low kidney function at baseline (estimated glomerular filtration rate < 40 mL/min) was associated with greater loss of renal function per year of follow-up (P = 0.007). Tacrolimus variability was not associated with late cytomegalovirus viremia.

CONCLUSIONS

High IPV in tacrolimus exposure beyond month 6 postliver transplantation was not associated with immune-mediated graft injury.

Area Under Trough Concentrations of Tacrolimus as a Predictor of Progressive Renal Impairment After Liver Transplantation

BACKGROUND

Tacrolimus minimization is usually restricted to patients with pretransplant renal impairment, and this strategy could result into worse renal outcomes after liver transplantation (LT).

METHODS

A consecutive cohort of 455 LT patients receiving tacrolimus-based immunosuppression was studied (2008-2013). Cumulative exposure to tacrolimus was calculated as the area under curve of trough concentrations (AUCtc). Patients were stratified as tacrolimus minimization, conventional, or high exposure, according to the thresholds based in the COMMIT consensus. Estimated glomerular filtration rates (eGFR) were assessed by the Modification of Diet in Renal Disease formula (MDRD-4) up to 5 years after LT.

RESULTS

Seventy patients (15.4%) had pretransplant eGFR < 60 mL/min, which was associated with increased mortality rates, particularly within the first 5 years post-LT (31.4% versus 17.5%; Breslow P = 0.010). After LT, there was an abrupt eGFR decline within the first 3 months (median 18.6 mL/min; P < 0.001), further decreasing up to 12 months (additional 3 mL/min), without any improvement thereafter. According to AUCtc, 33.7% of patients received tacrolimus minimization, 44.8% conventional exposure, and 21.5% high exposure. Conventional/high exposure to tacrolimus resulted in a more pronounced eGFR decline within the first 3 months when compared with minimization (23.3 mL/min versus 9.5 mL/min; P < 0.001). This gap was even higher in patients with initially preserved renal function. Tacrolimus AUCtc was an independent predictor of eGFR decline within the first 3 months after controlling for potential confounders.

CONCLUSIONS

AUCtc is a surrogate of cumulative exposure to tacrolimus and may be helpful for routine dose adjustments. Tacrolimus minimization should be universally attempted after LT to preserve renal function.

Improved Survival in Liver Transplant Patients Receiving Prolonged-release Tacrolimus-based Immunosuppression in the European Liver Transplant Registry (ELTR): An Extension Study

BACKGROUND

We compared, through the European Liver Transplant Registry, long-term liver transplantation outcomes with prolonged-release tacrolimus (PR-T) versus immediate-release tacrolimus (IR-T)-based immunosuppression. This retrospective analysis comprises up to 8-year data collected between 2008 and 2016, in an extension of our previously published study.

METHODS

Patients with <1 month follow-up were excluded; patients were propensity score matched for baseline characteristics. Efficacy measures included: univariate/multivariate analyses of risk factors influencing graft/patient survival up to 8 years posttransplantation, and graft/patient survival up to 4 years with PR-T versus IR-T. Overall, 13 088 patients were included from 44 European centers; propensity score-matched analyses comprised 3006 patients (PR-T: n = 1002; IR-T: n = 2004).

RESULTS

In multivariate analyses, IR-T-based immunosuppression was associated with reduced graft survival (risk ratio, 1.49; P = 0.0038) and patient survival (risk ratio, 1.40; P = 0.0215). There was improvement with PR-T versus IR-T in graft survival (83% versus 77% at 4 y, respectively; P = 0.005) and patient survival (85% versus 80%; P = 0.017). Patients converted from IR-T to PR-T after 1 month had a higher graft survival rate than patients receiving IR-T at last follow-up (P < 0.001), or started and maintained on PR-T (P = 0.019). One graft loss in 4 years was avoided for every 14.3 patients treated with PR-T versus IR-T.

CONCLUSIONS

PR-T-based immunosuppression might improve long-term outcomes in liver transplant recipients than IR-T-based immunosuppression.

Late T cell-mediated rejection may contribute to poor outcomes in adolescents and young adults with liver transplantation

Although poor long-term graft survival in LT in AYA is recognized, detailed epidemiological data are still lacking. L-TCMR may have poor outcomes. This study aimed to provide a detailed, epidemiological assessment of the association between AYA age and rejection. L-TCMR was defined in this study as TCMR with central vein or perivenular inflammation occurring later than 3 months after LT. A total of 342 patients who survived for at least 3 months after LT between 2005 and 2015 were enrolled. The AYA group (10-24 years) was compared with the C group (less than 10 years), and the incidence and outcomes of L-TCMR were analyzed. In total, 342 patients had LT; 38 of these were AYA with the mean follow-up period of 6.7 years. A total of 304 patients in C group had a mean follow-up period of 6.3 years (P = .28). The incidence of L-TCMR in AYA group was significantly higher than in C group (15.8% vs 4.6%, P = .006). The time to L-TCMR after LT was significantly shorter in AYA group (P = .01). Neither patient survival nor the incidence of non-adherence differed significantly between the groups (P = .18 and P = .89). The number of additional immunosuppressants after L-TCMR was significantly higher in the AYA group (P = .04). A high incidence of L-TCMR was observed in AYA group irrespective of non-adherence. AYA patients with L-TCMR should be followed carefully due to the poor results of post-treatment biopsy and the need for intensive immunosuppressive therapy.

The impact of caregiver post-traumatic stress and depressive symptoms on pediatric transplant outcomes

PTSS as well as symptoms of depression have been reported in children who experience a serious medical adversity as well as their caretakers. The adverse effects of PTSS, when experienced by the patients, on medical outcomes have been clearly documented. However, the impact of those symptoms, if any, when experienced by the caretakers on child outcomes has not been investigated prospectively. We evaluated whether caregiver PTSS and depression symptoms predict adherence to medications and medical outcomes in a prospective multisite study. Four hundred children participated in MALT. Caretaker PTSS were assessed by the IES and depressive symptoms by CES-D. During 2 years of follow-up, the MLVI was used to determine adherence. Centrally read, biopsy-confirmed organ rejection was the primary medical outcome. IES scores were not associated with either adherence or rejection outcomes. In contrast, there were significant correlations between CES-D (depression) scores and lower adherence, r = .13, P < .001, and a trend toward higher scores on the CES-D among those whose children had experienced rejection, 12.4 (SD = 10.9) versus 9.1 (SD = 8.6), P = .077. Caregivers' PTSS were not a risk factor for poor child outcomes in this cohort, whereas depression symptoms were associated with non-adherence and possibly increased rates of rejection. Further study can validate if caregivers' depression as opposed to PTSS confers greater risk and should be a focus during the clinical care of medically ill children.

Generalized and specific anxiety in adolescents following heart transplant

Mental health concerns are associated with worse outcomes after adult heart transplant. Illness-specific anxiety is associated with worsened psychological well-being after other solid organ transplants but has never been characterized after pediatric heart transplant. This single-center cross-sectional study aimed to evaluate illness-specific and generalized anxiety after heart transplantation in adolescents. A novel 12-item PHTF, GAD-7, and the PedsQL were administered. Univariate associations of demographics, clinical features, and medication adherence as measured by immunosuppression standard deviation with the PHTF and GAD-7 scores were evaluated. Internal consistency and validity of the PHTF were examined. In total, 30 patients participated. The most common illness-specific fears were retransplantation, rejection, and more generally post-transplant complications. The PHTF had good internal consistency (Cronbach α = .88). Construct validity was demonstrated between PHTF and GAD-7 (r = .62) and PedsQL (r = -.54 to -.62). 23% endorsed moderate to severe generalized anxiety symptoms. More severe symptoms were associated with older age at survey (P = .03), older age at listing (P = .01) and having post-transplant complications (P = .004). Patients with moderate or severe symptoms were more likely to report late immunosuppression doses (P = .004). Illness-specific and generalized anxiety may be prevalent after pediatric heart transplant. Screening for anxiety in adolescents post-transplant may identify those at risk for adverse outcomes including non-adherence. The PHTF is a brief, valid, and reliable instrument identifying illness-specific anxiety in this population.

Adherence to Medication During Transition to Adult Services

The transition from childhood and adolescence to adulthood is often tumultuous. For individuals with a chronic medical condition, this progression also includes a gradual transition to independence in healthcare management as well as a transfer in care location at some set point. As adolescents navigate these sometimes challenging processes, there is a significant risk for a decline in adequate health behaviors, which can have dire consequences. One of the most vital components of the transfer to adult care is medication adherence. Poor medication adherence puts patients at risk for worse outcomes, with the most profound being increased mortality for many conditions. In recent years, acknowledgment of the need to create evidence-based methods to aid patients during the transition period has been growing. This paper seeks to provide an overview of current research and recommendations for interventions to increase adherence to medication regimens during this period.

A Novel, Dose-Adjusted Tacrolimus Trough-Concentration Model for Predicting and Estimating Variance After Kidney Transplantation

Background and Objective

Given that a high intrapatient variability (IPV) of tacrolimus whole blood concentration increases the risk for a poor kidney transplant outcome, some experts advocate routine IPV monitoring for detection of high-risk patients. However, attempts to estimate the variance of tacrolimus trough concentrations (TTC) are limited by the need for patients to receive a fixed dose over time and/or the use of linear statistical models. A goal of this study is to overcome the current limitations through the novel application of statistical methodology generalizing the relationship between TTC and dose through the use of nonparametric functional regression modeling.

Methods

With TTC as a response and dose as a covariate, the model employs an unknown bivariate function, allowing for the potentially complex, nonlinear relationship between the two parameters. A dose-adjusted variance of TTC is then derived based on standard functional principal component analysis (FPCA). To assess the model, it was compared against an FPCA-based model and linear mixed-effects models using prediction error, bias, and coverage probabilities for simulated data as well as phase III data from the Astellas new drug application studies for extended-release tacrolimus.

Results

Our numerical investigation indicates that the new model better predicts dose-adjusted TTCs compared with the prediction of linear mixed effects models. Estimated coverage probabilities also indicate that the new model accurately accounts for the variance of TTC during the periods of large fluctuation in dose, whereas the linear mixed effects model consistently underestimates the coverage probabilities because of the inaccurate characterization of TTC fluctuation.

Conclusion

This is the first known application of a functional regression model to assess complex relationships between TTC and dose in a real clinical setting. This new method has applicability in future clinical trials including real-world data sets due to flexibility of the nonparametric modeling approach.

Electronic supplementary material

The online version of this article (10.1007/s40268-019-0271-2) contains supplementary material, which is available to authorized users.

Posttransplant Calcineurin Inhibitors Levels and Intrapatient Variability Are Not Associated With Long-term Outcomes Following Liver Transplantation

BACKGROUND

There is an interest in understanding the association between early calcineurin inhibitors exposure post-liver transplantation (LT) and long-term outcomes. We aimed to analyze this association exploring median calcineurin inhibitor levels and intrapatient variability (IPV) in a multicenter, retrospective cohort.

METHODS

Tacrolimus (Tac) and Cyclosporine (CsA) levels obtained during the first 15 days post-LT were collected. High immunosuppression (IS) was considered as a median of Tac, CsA blood trough levels 12 hours after drug administration, or blood levels 2 hours after drug administration higher than 10, 250, or 1200 ng/mL, respectively, or a peak of Tac >20 ng/mL. Optimal IS was defined as a median of Tac, CsA blood trough levels 12 hours after drug administration, or blood levels 2 hours after drug administration levels between 7 and 10, 150 and 250, or 800 and 1200 ng/mL. Low IS was defined as below the thresholds of optimal IS. IPV was estimated during the first 15 days post-LT.

RESULTS

The study included 432 patients with a median follow-up of 8.65 years. IS regimen was based on either Tac or CsA in 243 (56.3%) and 189 (43.8%), respectively. There were no differences in terms of graft loss among low versus optimal and high IS groups (P = 0.812 and P = 0.451) nor in high versus low IPV (P = 0.835). Only viral hepatitis and arterial hypertension were independently associated with higher graft loss (hazard ratio = 1.729, P = 0.029 and hazard ratio = 1.570, P = 0.021).

CONCLUSIONS

In contrast to what has previously been reported, no association was found between very early postoperative over IS or high IPV and long-term outcome measures following LT. Strategies aimed at reducing these long-term events should likely focus on other factors or on a different IS time window.

Intrapatient Variability of Tacrolimus Exposure in Solid Organ Transplantation: A Novel Marker for Clinical Outcome

The calcineurin-inhibitor tacrolimus (Tac) provides an acceptable balance between prevention of allograft rejection and drug-related adverse effects, making it the standard of care in all types of solid organ transplantation for the last 2 decades. Recent data have demonstrated that high intrapatient variability (IPV) in Tac predose trough concentrations has deleterious effects on allograft survival. The underlying mechanisms by which a high Tac IPV shortens allograft survival are acute and chronic rejection, donor-specific anti-HLA antibodies, and progressive fibrotic damage to the graft. Modifiable causes of high Tac IPV include medication nonadherence (MNA), drug interactions, nutritional interferences, and concurrent diseases. Recognizing high Tac IPV as an important prognostic risk factor after solid organ transplantation requires understanding of the definitions, the use of correct diagnostic metrics, and methodology. Therapeutic interventions aimed at reducing Tac IPV are targeted on improving MNA, avoiding or adjusting drug interactions, drug dosing assists, and educational support of recipients.

Medication non-adherence after kidney transplantation: A critical appraisal and systematic review

Medication non-adherence is one of the most important causes for shortened graft survival subsequently leading to a reduction in kidney graft survival results. Our aim was to provide an overview of its prevalence, risk factors, diagnostic methods and interventions to improve adherence in kidney transplant recipients. Therefore, we systematically searched the databases PubMed, COCHRANE Library, Web of Science and EMBASE for studies addressing "medication adherence", "compliance", "adherence", "kidney transplantation" and "life style factors". We identified 96 studies that satisfied our inclusion criteria. A problematic lack of a uniformly accepted definition for non-adherence was found, consequently leading to a wide range in non-adherence prevalence (36-55%). Using one uniformly accepted non-adherence definition should therefore be encouraged. A wide range in diagnostic methods makes it difficult to accurately detect non-adherence. Heterogeneous results of intervention studies make it difficult to select the best adherence enhancing method, challenging the battle against medication non-adherence. Literature suggests a combination of personalized interventions, based on patient-specific non-adherent behavior, to be most successful in improvement of adherence. High quality diagnostic methods and multidisciplinary, personalized interventions with focus on relevant clinical outcome are essential in overcoming medication non-adherence in kidney transplant recipients.

The Medication Level Variability Index (MLVI) as a potential predictive biomarker of graft-versus-host disease in pediatric hematopoietic stem cell transplant patients

The purpose of this study was to examine the potential predictive value of the Medication Level Variability Index (MLVI) biomarker with graft-versus-host disease (GVHD) in the pediatric hematopoietic stem cell transplant (HSCT) patient during the acute phase post-transplant. This retrospective descriptive study evaluated a total of 406 tacrolimus levels in 64 patients over a varying number of weeks per participant (median = 8, min = 3, max = 11). Patients were followed until Day 100 post-transplant or tacrolimus taper began. A total of 72 episodes of non-therapeutic levels occurred during the acute phase. Of those, 40 (56%) were <5, while 32 (44%) were >15. Approximately 39% (n = 25 of 64) of the participants in the study developed GVHD post-discharge. Those with GVHD had a statistically significantly higher MLVI than those that did not (median = 3.1, IQR = 2.5-4.7 vs 2.3, IQR = 1.6-3.4, respectively, P = 0.024). Using a criterion of MLVI > 3, there was a statistically significant increased likelihood of GVHD (OR = 3.82, 95% CI=1.32 = 11.04, P = 0.013). Area under the curve (AUC) calculation for the sensitivity and specificity of using the MLVI for GVHD was also conducted. The AUC of 0.67 was statistically significant (95% CI 0.53-0.81, P = 0.024). This is the first-known study to report the use of the MLVI in HSCT patients. The MLVI is associated with a main adverse outcome related to HSCT, GVHD. These results are encouraging of a new potential biomarker to evaluate tacrolimus serum assay levels and identify patients at risk for developing GVHD.

Efficacy and safety of prolonged-release versus immediate-release tacrolimus inde novoliver transplant recipients in South Korea: a randomized open-label phase 4 study (MAPLE)

Background

Prolonged-release tacrolimus is associated with better long-term graft and patient survival than the immediate-release formulation in liver transplant patients. However, no clinical data are available to assess the efficacy and safety of early conversion from twice-daily, immediate-release tacrolimus to once-daily, prolonged-release tacrolimus in de novo liver transplant recipients in Korea.

Methods

A 24-week, randomized, open-label study was conducted in 36 liver transplant recipients. All patients received immediate- release tacrolimus (0.1–0.2 mg/kg/day, divided into two doses) for 4 weeks after transplantation, at which time 50% of the patients were converted, at a ratio of 1 mg to 1 mg, to prolonged-release tacrolimus (once-daily). The primary efficacy endpoint was the incidence of biopsy-confirmed acute rejection (BCAR) from weeks 4 to 24 after transplantation (per-protocol set). Medication adherence, adverse event profiles, laboratory tests, vital signs, and physical changes were also recorded.

Results

BCAR frequency at 24 weeks was similar between the two treatment groups; two cases (mean±standard deviation, 0.14±0.53 cases) of BCAR were reported in one patient treated with prolonged-release tacrolimus (n=14), while no such cases were reported among patients treated with immediate-release tacrolimus (n=12). The tacrolimus blood concentration at weeks 12 and 24, medication adherence, and adverse event profiles were also similar between the formulations, with no unusual laboratory test results, vital signs, or physical changes reported.

Conclusions

Early conversion to a simplified, once-daily, prolonged-release tacrolimus regimen may be an effective treatment option for liver transplant recipients in Korea. Larger-scale studies are warranted to confirm non-inferiority to immediate-release tacrolimus formulation in de novo liver transplant recipients.

Reduction of exposure to tacrolimus trough level variability is associated with better graft survival after kidney transplantation

PURPOSE

High tacrolimus trough drug level variability was found to be associated with reduced graft survival. The primary goal of this study was to find whether reduction of exposure to high tacrolimus trough level variability in patients in which previously had high variability was associated with better graft survival.

METHODS

All tacrolimus drug level values in patients that underwent kidney transplantation at our center between 2006 and 2015 were collected. Exposure to variability was calculated using a time-weighted coefficient of variability (TWCV). Time-dependent univariate and multivariate Cox proportional hazard models were used to analyze the primary outcome of graft survival and to determine a cutoff value for TWCV as a predictor of this outcome.

RESULTS

A total of 878 patients were included in the study with a median follow-up of 1263 days. TWCV above 25% was significantly associated with reduced graft survival (HR3.66, 95% CI 2.3-5.8, p < 0.001). Of the 480 patients (54.7%) who had a cumulative TWCV of > 25% at a certain time during the follow-up, 110 (22.9%) later returned to a cumulative TWCV of less than 25%. Reduction of TWCV to values below 25% was associated with a hazard of graft loss that was not different from patients who had cumulative TWCV of less than 25% during the entire follow-up period (HR 1.81, 95% CI 0.71-4.62, p = 0.218 and HR 1.08, 95% CI 0.39-2.99, p = 0.780) in univariate and multivariate analyses, respectively.

CONCLUSIONS

Monitoring TWCV can help detect the high-risk patients. Interventions intended to reduce variability on long-term graft survival may have a positive effect on graft survival.