Evaluating non-adherence to immunosuppressant medications in pediatric liver transplant recipients

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.

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.

Feasibility of steroid-free tacrolimus-basiliximab immunosuppression in pediatric liver transplantation and predictors for steroid requirement

Avoidance of steroids in pediatric liver transplantation may reduce toxicity and morbidity. The aim of this study was to analyze the feasibility of a steroid-free tacrolimus-basiliximab immunosuppression scheme, the risk factors associated with steroid requirement, and safety parameters. Patients who underwent liver transplantation for biliary atresia between 2011 and 2019 were included and followed for 6 months after transplantation. Immunosuppression consisted of tacrolimus-based treatment with basiliximab induction. Steroid-free survival was estimated, and risk factors for steroid requirement were evaluated using multivariate Cox regression analysis. A total of 76 patients were included, of whom 42 (55.3%) required steroids (>14 d) due to biopsy-proven acute rejection (47.6%, n = 20), instability in liver function tests (35.7%, n = 15), tacrolimus-related adverse drug reactions (14.3%, n = 6), or other reasons (bronchospasm episode, n = 1). Steroid-free survival was 45.9% (95% CI, 35.9-58.8). Independent factors associated with steroid requirement included tortuosity in tacrolimus trough levels (≥1.76 vs. <1.76: HR 5.8, 95% CI, 2.6-12.7; p < 0.001) and mean tacrolimus trough levels (≥ 6.4 ng/mL vs. < 6.4 ng/mL: HR 0.4, 95% CI, 0.2-0.7; p = 0.002). The rate of bacterial and viral infections was comparable between patients with and without steroids, although in the former group, cytomegalovirus infection developed earlier ( p = 0.03). Patients receiving steroids had higher total cholesterol, LDL, and HDL levels ( p < 0.05) during follow-up, but no changes in the height Z-score were observed 1 year after transplantation. Basiliximab induction in combination with tacrolimus-based treatment avoided steroid requirements in 45% of the patients. Tacrolimus variability and trough levels below 6.4 ng/mL independently increased the risk of steroid requirement. Further efforts should be focused on personalizing immunosuppressive treatment.

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.

Mismatch epitope load predicts de novo-DSA-free survival in pediatric liver transplantation

BACKGROUND

Our knowledge of de novo anti-HLA donor-specific antibodies (dnDSA) in liver transplantation continues to be defined. We hypothesized that differences of HLA-DR/DQ mismatches can improve precision in alloimmune risk categorization and be applied to tailor immunosuppression.

METHODS

A retrospective chart review of 244 pediatric patients consecutively transplanted at our center between 2003 and 2019 was performed to identify patients tested for dnDSA. Records were queried for: demographics, pre-transplant diagnosis, biopsy-proven T-cell-mediated rejection (TCMR), radiology proven biliary complications, tacrolimus trough levels, dnDSA characteristics, and HLA typing. The eplet mismatch analyses were performed using HLAMatchmaker^™ 3.1. All statistical analyses were conducted using R software version 3.40.

RESULTS

There were 99 dnDSA-negative patients and 73 dnDSA-positive patients (n = 70 against class II and n = 3 against class I and II). ROC analysis identified optimal cutoff of eplet mismatch load for dnDSA and defined risk groups for an alloimmune outcome. Kaplan-Meier curves and log-rank tests showed high eplet mismatch load was associated with shorter dnDSA-free survival (log-rank p = .001). Multivariable Cox regression models showed that tacrolimus coefficient of variation and tacrolimus mean levels were significantly associated with dnDSA-free survival (p < .001 and p = .036). Fisher's exact test showed that dnDSA was associated with an increased likelihood of TCMR (OR 14.94; 95% CI 3.65 - 61.19; p < .001). Patients without TCMR were more likely to have dnDSA to HLA-DQ7 and less likely to have dnDSA to HLA-DQ2 (p = .03, p = .080).

CONCLUSIONS

Mismatched epitope load predicts dnDSA-free survival in pediatric liver transplant, while dnDSA specificity may determine alloimmune outcome.

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.

Long-term outcomes in pediatric patients who underwent living donor liver transplantation for biliary atresia

BACKGROUND

There is no consensus about long-term outcomes in patients with biliary atresia. We retrospectively reviewed the long-term outcomes in pediatric patients who underwent living donor liver transplantation for biliary atresia.

METHODS

Between May 2001 and December 2020, 221 (73%) of 302 pediatric patients who underwent living donor liver transplantation had biliary atresia. The median age at living donor liver transplantation was 1.2 (range 0.2-16.5) years, and follow-up was 10.3 ± 5.5 years.

RESULTS

The 10-year graft survival rates in patients with and without biliary atresia were 94% and 89%, respectively (P = .019). The 10-year graft survival was significantly poorer in patients ≥12 years of age (84%) versus those <12 years of age at living donor liver transplantation (0-2 years: 95%; 2-12 years: 96%) (P = .016). The causes of graft failure in patients with biliary atresia included late-onset refractory rejection (n = 6), bowel perforation (n = 2), and acute encephalitis (n = 2), as well as cerebral hemorrhage, hepatic vein thrombosis, and sepsis (n = 1 for all). All 7 patients with graft failure due to refractory rejection and hepatic vein thrombosis underwent repeated liver transplantation and are alive in 2021. The rates of post-transplant portal vein complications and early-onset acute cellular rejection in patients with biliary atresia were higher than in those without biliary atresia (P = .042 and P = .022, respectively). In 2021, of 60 adolescents with biliary atresia, 14 (23%) reported medication nonadherence. The rate of liver dysfunction due to late-onset acute cellular rejection and graft failure due to late-onset refractory rejection in patients with nonadherence was higher than in patients with satisfactory adherence (P = .009).

CONCLUSION

The long-term prognosis after living donor liver transplantation in pediatric patients with biliary atresia is quite good. However, long-term support to enhance medication adherence is required in adolescents with biliary atresia.

Tacrolimus trough levels in kidney transplant recipients

BACKGROUND

It is very important that kidney transplant recipients (KTRs) take immunosuppressive drugs to prevent graft rejection. This study aimed to identify the tacrolimus trough levels (TTL)-mean, TTL-standard deviation (SD), and TTL- coefficient of variation (CV) as well as factors affecting these values over a 2-year period in clinically stable patients > 5 years after kidney transplantation (KT).

METHODS

This retrospective study analyzed data from 248 adult outpatients > 5 years after KT. Medical chart data, including TTL, graft rejection, and tacrolimus dose change during a 2-year period, between January 2017 and December 2018, were collected. Multivariable regression analyses were conducted to determine the factors influencing the TTL-mean, TTL-SD, and TTL-CV.

RESULTS

The TTL-mean, TTL-SD, and TTL-CV were 6.00 ± 1.07 ng/mL, 1.51 ± 1.09 ng/mL, and 0.25 ± 0.14, respectively. The TTL-mean, TTL-SD, and TTL-CV did not differ according to sex, type of donor, retransplant, pretransplant kidney disease, body mass index, or posttransplant time; hence, they are stable in kidney transplant recipients > 5 years after KT. The higher the TTL-mean, the higher the TTL-SD. Age and the TTL-SD significantly predicted the TTL-mean (p < .001). Tacrolimus dose change and the TTL-mean significantly predicted the TTL-SD (p < .001). Tacrolimus dose change significantly predicted the TTL-CV (p = .008).

CONCLUSION

In clinically stable KTRs, TTL-SD and TTL-CV change sensitively in relation to tacrolimus dose changes. Therefore, changes in TTL-SD and TTL-CV in stable KTRs with no tacrolimus dose change require medical interest and attention.

LIVER TRANSPLANTATION: TACROLIMUS BLOOD LEVELS VARIATION AND SURVIVAL, REJECTION AND DEATH OUTCOMES

BACKGROUND

Immunosuppressive drugs have important role in transplant of solid grafts, it aim avoid episodes of acute and chronic rejection and improving graft survival and patient survival. In Brazil, in 2016, liver transplantation was the third most frequent, with 1,880 transplants performed, of which 150 in Rio Grande do Sul. Several studies evaluated the association between variability in blood levels of immunosuppressive tacrolimus and late acute cellular graft rejection.

OBJECTIVE

To investigate the association of tacrolimus blood levels with clinical outcomes late acute cellular rejection, death, patient survival and graft survival in patients undergoing liver transplantation.

METHODS

This is a retrospective longitudinal study including patients submitted to adult liver transplantation by the Liver Transplantation Group in the Santa Casa de Misericórdia Hospital of Porto Alegre, from January 2006 to January 2013, and who used tacrolimus as immunosuppressive therapy.

RESULTS

Of the 127 patients included in the study, the majority were male (70.1%), 52-60 years old (33.9%) at the transplant. The most frequent causes of liver transplantation in this series were hepatitis C virus and hepatocellular carcinoma (24.4%) and alcohol (15.7%). Thirteen patients had late acute cellular rejection (10.2%); of these, three had two episodes. Regarding severity classification, seven patients had mild late acute cellular rejection. The mean time of rejection after liver transplantation was 14 months (ranging from 8 to 33 months). Overall survival was 8.98 years. Regarding tacrolimus blood levels, 52 patients with a variation ≥2 standard deviations were identified. Of these patients, eight had rejection; however, the association was not significant (P=0.146). A significant association was found between variation ≥2 standard deviations in tacrolimus blood levels and death (P=0.023) and survival (P=0.019). Regarding 5-year follow-up of graft survival, being two standard deviations above increases by 2.26 times the risk of transplanted graft loss, and for each unit of increase of standard deviation of tacrolimus blood levels there is a two-fold increase in the risk of graft loss in 5 years.

CONCLUSION

Increased risk of graft loss associated with increased standard deviations of tacrolimus blood levels may indicate the need for more rigorous and prospective monitoring of tacrolimus blood levels.

Examining the association of medical complications and posttraumatic stress symptoms in pediatric solid organ transplant patients and their caregivers

BACKGROUND

Post-traumatic stress symptoms (PTSS) have been reported by pediatric solid organ transplant (SOT) patients and their caregivers well after transplantation. This study examined the relationship between PTSS, medication adherence, and medical complications in SOT patients and their caregivers. A secondary aim examined the association between patient and caregiver-reported PTSS.

METHODS

Pediatric SOT patients (N = 69) and caregivers (N = 73) reported on PTSS by completing the Child PTSD Symptom Scale (patients 8-17 years) or the Impact of Events Scale-Revised (patients 18 years and older and caregivers). Patient medication adherence was assessed using the Medication Level Variability Index (MLVI). Patients were dichotomized as experiencing a post-transplant medical complication (ie, transplant-related hospital admission prior to the year completing measures of PTSS) or no complications.

RESULTS

Medication adherence was not significantly associated with patient or caregiver PTSS. A moderate effect size was found for elevated young adult and caregiver PTSS and the presence of a medical complication. Generally, the association between self-reported patient and caregiver PTSS was low.

CONCLUSIONS

The presence of elevated PTSS in young adult patients may be partially explained by the presence of proximal medical complications and more so by comorbid psychiatric diagnoses in child and adolescent patients (based on exploratory analyses). Caregivers of patients with medical complications within the past year reported higher levels of PTSS. Overall, transplantation and its associated impact on PTSS may be unique experience for patients versus caregivers. Qualitative research may further elucidate these experiences and inform future clinical interventions.

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.

Toward a better understanding: An exploration of provider perceptions in pediatric hematopoietic stem cell transplant adherence

Pediatric HSCT patients endure complicated treatment regimens, lifestyle modifications, and a lifetime of long-term follow-up. Treatment adherence in this population is understudied and prevalence unknown. Providers (physicians and advanced practice nurses) in this study completed an online-structured questionnaire about definition, assessment, and perceived rates of adherence. Researchers' extracted 187 statements from participants' responses. The majority (n = 12, 71%) of providers reported adherence as a primary concern in outpatient HSCT. The major concern for providers was the potential of non-adherence to negatively affect outcomes. Providers also shared clinical examples of non-adherence. This study contributes to a better understanding of providers' perceptions of adherence within pediatric HSCT. Additional research is needed to describe, define, and improve adherence in pediatric HSCT to ultimately improve outcomes and quality of life for this vulnerable population.

Implementing a Process to Systematically Identify and Address Poor Medication Adherence in Pediatric Liver Transplant Recipients

Objectives

Poor adherence to medication following pediatric liver transplantation remains a major challenge, with some estimates suggesting that 50% of adolescent liver transplant recipients exhibit reduced medication adherence. To date, no gold standard has emerged to address this challenge; however, system interventions are most likely to be successful. We sought to implement a system to identify and address adherence barriers in a liver transplant clinic.

Methods

Using structured quality improvement methods, including multiple plan-do-study-act cycles, we developed a system to screen for patients at risk of poor adherence, identify patient- and/or parent-reported barriers to adherence, and partner with patients to overcome identified barriers. We developed a process to track key outcomes, including the variability in tacrolimus trough levels and episodes of late acute cellular rejection.

Results

The practice saw a total of 85 patients over 6 months, and about half were females. Over this period, the improvement team implemented this system-level process with high reliability (>90% of patients received the bundle of interventions). The most commonly identified adherence barrier by patients and caregivers was "forgetting." The second most commonly identified adherence barrier by patients was that the medication "gets in the way of their activities," whereas by caregivers, it was "difficulty swallowing pills."

Discussion

We identified challenges and opportunities to screen for poor adherence and identify patient- and/or caregiver-reported barriers to immunosuppression adherence. Identifying such barriers and partnering with patients to overcome those barriers using patient-centered, barrier-specific interventions could improve long-term graft survival through improved medication adherence.

Adults transplanted as children as retransplant candidates: Analysis of outcomes support optimism in a population mislabeled as high risk

Adult liver transplant programs have heretofore been hesitant to perform liver retransplantation in adult patients who underwent primary liver transplantation as a child (P_A). Areas of concern include: (a) potential disruption in care when transferring from a pediatric to an adult transplant center; (b) generally inferior outcomes of retransplantation; (c) reputation of young adults for non-adherence to post-transplant regimen; and (d) potential higher work effort for equivalent outcomes. To examine these concerns, we reviewed data on all US liver adult retransplants from 10/01/1987 to 9/30/2017. We propensity matched the P_A patients to patients who received both primary and retransplantation as adults (A_A), with ≥550 days between transplants. A mixed Cox proportional hazards model with program size and time period of transplantation as random variables revealed that retransplantation of P_A patients produced no significantly different graft survival or patient survival rates than retransplantation of the matched A_A patients. Therefore, inferior rates of liver retransplantation in these patients and concerns about continuity of care in changing transplant programs are not as believed in the wider liver transplant community. In conclusion, liver transplant centers should be optimistic about retransplanting adults who received their primary transplants as children.

Once-daily prolonged-release tacrolimus versus twice-daily tacrolimus in liver transplantation

OBJECTIVE

For patients who have received a kidney transplant, studies have shown that once-daily prolonged-release tacrolimus (TAC) has similar efficacy and safety to standard twice-daily dosing. The purpose of this study was to perform a meta-analysis to compare the effectiveness and safety of daily TAC (TAC qd) versus standard twice-daily TAC (TAC bid) administration in liver transplantation (LT).

DESIGN

Meta-analysis.

SETTING AND PARTICIPANTS

We systematically searched the PubMed/MEDLINE, Web of Science, and Cochrane Library databases for studies comparing outcomes of LT patients who received TAC qd versus TAC bid.

OUTCOME MEASURES

Results were reported as odds ratios (ORs) with 95% CIs.

RESULTS

Six studies, which included 5179 LT recipients (TAC qd = 951; TAC bid = 4228) were included in the analysis. The TAC qd group had a low 1-year graft loss rate (OR 0.70 [95% CI 0.54-0.91], P = 0.008) and lower rate of biopsy-proven acute rejection (BPAR) at 90 days (OR 0.46 [95% CI 0.24-0.89], P = 0.02) compared with the TAC bid group. There was no significant difference in 1-year mortality or the incidence of adverse events after LT between the 2 groups.

CONCLUSIONS

Current evidence suggests that TAC qd is safe and effective for LT patients during the first year after transplantation. Longer-term follow-up studies are necessary to determine if TAC qd is safe and effective beyond the first year after LT.

20- to 25-year patient and graft survival following a single pediatric liver transplant-Analysis of the United Network of Organ Sharing database: Where to go from here

To understand factors contributing to liver graft loss and patient death, we queried a national database designed to follow pediatric patients transplanted between 1987 and 1995 till adulthood. A comparison was made to a cohort transplanted between 2000 and 2014. The 5-, 10-, 15-, 20-, and 25-year patient survival and graft survival were 95.5%, 93.7%, 89.1%, 80.8%, and 73.1%, and 92.5%, 86.7%, 77.6%, 68.7%, and 62.2%, respectively. The twenty-year patient/graft survival was significantly worse in those transplanted between 5 and 17 years of age compared to those transplanted at <5 years of age (P < 0.001). For the modern era cohort, the 3-year patient survival was significantly lower in children transplanted at 16-17 years of age compared to those transplanted at <5 and 11-15 years of age (P ≤ 0.02). The 3-year graft survival was similarly lower in children transplanted at 16-17 years of age compared to those transplanted at <5, 5-10, and 11-15 years of age (P ≤ 0.001). Infection as a cause of death occurred either early or >15 years post-transplant. Chronic rejection remained the leading cause of graft loss in both cohorts and the commonest indication for retransplantation 20-25 years following primary transplant. Further research is required to identify modifiable factors contributing to development of chronic rejection.

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.

Pediatric Heart Transplantation: Transitioning to Adult Care (TRANSIT): Feasibility of a Pilot Randomized Controlled Trial

BACKGROUND

Young-adult heart transplant recipients transferring to adult care are at risk for poor health outcomes. We conducted a pilot randomized controlled trial to determine the feasibility of and to test a transition intervention for young adults who underwent heart transplantation as children and then transferred to adult care.

METHODS

Participants were randomized to the transition intervention (4 months long, focused on heart-transplant knowledge, self-care, self-advocacy, and social support) or usual care. Self-report questionnaires and medical records data were collected at baseline and 3 and 6 months after the initial adult clinic visit. Longitudinal analyses comparing outcomes over time were performed using generalized estimating equations and linear mixed models.

RESULTS

Transfer to adult care was successful and feasible (ie, excellent participation rates). The average patient standard deviation of mean tacrolimus levels was similar over time in both study arms and < 2.5, indicating adequate adherence. There were no between-group or within-group differences in percentage of tacrolimus bioassays within target range (> 50%). Average overall adherence to treatment was similarly good in both groups. Rates of appointment keeping through 6 months after transfer declined over time in both groups.

CONCLUSIONS

The feasibility of the study was demonstrated. Our transition intervention did not improve outcomes.

Intra-patient variability in tacrolimus exposure in pediatric liver transplant recipients: Evolution, risk factors, and impact on patient outcomes

BACKGROUND

This study aims to investigate the evolution and factors associated with TAC IPV and its impact on patient outcomes in pediatric LT recipients.

METHODS

This is a retrospective study including 41 children. The TAC IPV was expressed as the coefficient of variation and was calculated for years 1-5 following LT. The number of missed clinic appointments was used as a surrogate marker for therapy adherence.

RESULTS

We identified a decrease in the TAC IPV during the first 3 years after LT (P < 0.01). Serum albumin in the first year (P = 0.03), hematocrit (P = 0.02) and total bilirubin (P = 0.04) in the third year, and therapy adherence (P < 0.01) in the fifth year were associated with TAC IPV. High TAC IPV was associated with biopsy-proven acute allograft rejection (P = 0.04) and the need for biopsy during the first year (P = 0.02). There was a borderline association between TAC IPV and donor-specific antibodies (P = 0.08) and CMV viremia (P = 0.07). High TAC IPV was a predictor of need for liver biopsy and AR with an odds ratio of 1.04 (95% CI 1.0-1.1; P = 0.03) and 1.04 (95% CI 1.0-1.1; P = 0.05), respectively.

CONCLUSIONS

Our results highlight the impact of biological factors on TAC IPV during the early LT follow-up and later also therapy adherence. High TAC IPV may be associated with adverse patient outcomes.

Adherence to medical regimen after pediatric liver transplantation: a systematic review and meta-analysis

PURPOSE

Adherence to the medical regimen after pediatric liver transplantation is crucial for good clinical outcomes. However, the existing literature provides inconsistent evidence regarding the prevalence of and risk factors for nonadherence to the medical regimen after pediatric liver transplantation. This study aimed to investigate such nonadherence after pediatric liver transplantation and risk factors associated with this nonadherence using findings of reported studies.

METHODS

The electronic databases of Excerpta Medica, Ovid Technologies, PubMed and WanFang Data were searched using the keywords "adherence", "liver transplant" and "paediatric". Additionally, relevant references cited in related studies were used to obtain original articles. Using 22 original articles, data regarding nonadherence to the medical regimen after pediatric liver transplantation were quantitatively combined, and risk factors associated with nonadherence were qualitatively identified. Average rates of nonadherence in four areas of medical regimens were calculated. The heterogeneity of the included original articles was also analyzed. When I ²>50 and P<0.05, a random effects model was used; otherwise, a fixed effects model was used. Moreover, Egger's and Begg's tests were used to evaluate publication bias, if any, and original articles with P>0.05 were considered to have no publication bias.

RESULTS

The clinical attendance nonadherence rate was 45% (95% confidence interval [CI]: 39-51), global nonadherence rate was 17% (95% CI: 13-21) and immunosuppression non-adherence rates were 39% (95% CI: 26-52) and 34% (95% CI: 30-39) for cyclosporine and tacrolimus, respectively. Risk factors included older age of the pediatric patient, low family cohesion, poor social functioning, poor mental health and single-parent family.

CONCLUSIONS

The nonadherence rate in pediatric liver transplantation is high. Therefore, intervention on the basis of risk factors, such as mental health and family function, may be necessary. Moreover, a standard technique for assessing nonadherence to the medical regimen after pediatric liver transplantation, comprising as many dimensions as possible, is required in order to be more objective and comprehensive when assessing nonadherence.

Medication adherence in pediatric transplantation and assessment methods: a systematic review

Background: Medication adherence is a major concern in public health. It is fully established that immunosuppressive therapy (IT) and concomitant medications affect transplant outcomes in the pediatric population, showing interest in adherence to this therapy. The aim of the present review was to report on medication adherence in pediatric population post-transplantation. This will enable us to know the situation in this particular population. Methods: A literature search was performed using the MEDLINE database. Studies that were published from January 1999 to January 2016 in English language and which investigated medication adherence in pediatric transplantation were included. The type of organ and the methods used to assess medication adherence were studied. Results: A total of 281 records were identified, from which 34 studies were selected: 38% (n=13) on kidney transplantation, 32% (n=11) on liver transplantation, and 23% (n=10) on the transplantation of other organs. Medication adherence was found to be lower than 80% in two-thirds of the studies (64%), and varied from 22% to 97%. This wide range was explained in part by the important heterogeneity of assessment methods among studies. The methods used were objective, non-objective, or combined both types. Most studies did not fully describe the data collected: the time since transplantation, the period over which adherence was assessed, the population, the medications, and the threshold discriminating adherence and non-adherence. Conclusion: The present study found poor medication adherence in the pediatric population post-transplantation. There was a wide range of medication adherence, explained largely by the heterogeneity of assessment methods. Future studies must consider the characteristics of each methodology, but also the threshold defining adherence should be chosen on the basis of clinical outcomes, and describe all data collected to gain precision. To improve adherence in this population, it is essential to identify factors influencing medication (IT and concomitant medications) adherence.

Survival Time to Biopsy-Proven Acute Rejection and Tacrolimus Adverse Drug Reactions in Pediatric Liver Transplantation

BACKGROUND

Despite advances in surgical procedures and the optimization of immunosuppressive therapies in pediatric liver transplantation, acute rejection (AR) and serious adverse drug reaction (ADR) to tacrolimus still contribute to morbidity and mortality. Identifying risk factors of safety and efficacy parameters may help in optimizing individual immunosuppressive therapies. This study aimed to identify peritransplant predictors of AR and factors related to the risk of ADR to tacrolimus in a large Latin American cohort of pediatric liver transplant patients.

METHODS

We performed a retrospective cohort study in a pediatric liver transplant population (n = 72). Peritransplant variables were collected retrospectively including demographic, clinical, laboratory parameters, genomic (CYP3A5 donor and recipients polymorphism), and tacrolimus trough concentrations (C0) over a 2-year follow-up period. Variability in tacrolimus C0 was calculated using percent coefficient of variation and tortuosity. ADR- and AR-free survival rates were calculated using the Kaplan-Meier method, and risk factors were identified by multivariate Cox regression models.

RESULTS

Cox-proportional hazard models identified that high tortuosity in tacrolimus C0 was associated with an 80% increased risk of AR [hazard ratio (HR), 1.80; 95% confidence interval (CI), 1.01-3.22; P < 0.05], whereas steroid in maintenance doses decreased this risk (HR, 0.56; 95% CI, 0.31-0.99; P < 0.05). Forty-six patients experienced at least one ADR including hypomagnesemia, nephrotoxicity, hypertension, malignancies, and tremor as a first event. Multivariate analysis showed that C0 values 10 days before the event (HR, 1.25; 95% CI, 1.21-1.39; P < 0.0001) and CYP3A5 expresser recipients (HR, 2.05; 95% CI, 1.03-4.06; P < 0.05) were independent predictors of ADR.

CONCLUSIONS

Tacrolimus C0 values, its variability, and CYP3A5 polymorphisms were identified as risk factors of AR and tacrolimus ADR. This knowledge may help to control and reduce their incidence in pediatric liver transplant patients. Prospective studies are important to validate these results.

Predicting Health Care Utilization and Charges Using a Risk Score for Poor Adherence in Pediatric Kidney Transplant Recipients

Pediatric kidney transplant recipients must follow a complicated regimen of timely adherence to immunosuppressant medication, routine blood work, and medical follow-up visits. Failure to adhere to the recommended regimen can result in medical complications and costly treatment. We developed a novel risk score to identify patients at risk for poor adherence behaviors and evaluated whether it would predict future health care utilization and charges. Our risk stratification score combined three simple pass/fail metrics of adherence derived directly from the electronic health record including standard deviation of immunosuppression drug levels, timely laboratory monitoring, and timely clinic visits as indicated by our clinical protocol. Risk for poor adherence was assessed over a three-month period. Linear regression was used to predict subsequent health care charges and utilization. Greater than 75% of patients had some degree of nonadherence risk during the study period, but there were no significant differences found on any outcomes for the overall score. However, when the individual components of the overall risk score were evaluated independently, patients with tacrolimus drug level standard deviation ≥2 (e.g., a marker of poor adherence) had greater health care utilization (e.g., hospitalizations) and increased total charges. Additionally, patients who did not follow up in clinic at least every 4 months had more ED visits and ED-related charges, but fewer hospitalizations. Regular clinic visits and minimizing drug level variation may deter future costly ED visits and hospitalizations.

Intrapatient Variability in the Pharmacokinetics of Etanercept Maintenance Treatment

AIM

Etanercept has shown to mediate a favorable effect on immune-mediated inflammatory diseases (IMID), including plaque psoriasis. Therapeutic drug monitoring (TDM) of etanercept could improve clinical outcome and cost-effectiveness. A high intrapatient variability (IPV) of etanercept trough concentrations at standard dosing would reduce the feasibility of therapeutic drug monitoring. Studies have focused on the interpatient differences associated with the exposure to biologics. The aim of this study was to determine IPV of etanercept and correlate etanercept trough concentrations and IPV with treatment response.

METHODS

Repetitive serum samples of 29 psoriasis patients on standard etanercept maintenance treatment were collected. In these samples, etanercept trough concentrations were determined and IPV was assessed in relation to response to treatment.

RESULTS

The median IPV of etanercept trough concentrations was 33.7% (Q1 = 21.3% and Q3 = 51.7%) ranging from 8% to 155%. All 6 nonresponders showed an IPV at or above the median value of 33.7%. The 6 nonresponders showed a higher IPV as compared to the 23 responders (53.9% versus 24.2%; P = 0.031). The mean etanercept trough concentration for each patient ranged from 0.7 to 6.8 mcg/mL, with a median trough concentration of 2.7 mcg/mL. Patients with an IPV above the median had lower mean etanercept trough concentrations compared to patients with an IPV below the median (1.96 mcg/mL, 95% CI, 1.7-2.4 versus 3.2 mcg/mL, 95% CI, 2.7-4.0; P = 0.001).

CONCLUSIONS

The median IPV of etanercept trough concentrations in this study population was 33.7%. A higher IPV was correlated with lower etanercept trough concentrations and with nonresponsiveness. Prospective trials are required to demonstrate the value of adjusting the etanercept dose based on drug trough concentrations. The relatively high IPV observed in this study may complicate therapeutic drug monitoring.

Meeting report: FDA public meeting on patient-focused drug development and medication adherence in solid organ transplant patients

The Food and Drug Administration (FDA) held a public meeting and scientific workshop in September 2016 to obtain perspectives from solid organ transplant recipients, family caregivers, and other patient representatives. The morning sessions focused on the impact of organ transplantation on patients' daily lives and the spectrum of activities undertaken to maintain grafts. Participants described the physical, emotional, and social impacts of their transplant on daily life. They also discussed their posttransplant treatment regimens, including the most burdensome side effects and their hopes for future treatment. The afternoon scientific session consisted of presentations on prevalence and risk factors for medication nonadherence after transplantation in adults and children, and interventions to manage it. As new modalities of Immunosuppressive Drug Therapy are being developed, the patient perceptions and input must play larger roles if organ transplantation is to be truly successful.

A systematic review of immunosuppressant adherence interventions in transplant recipients: Decoding the streetlight effect

Non-adherence to immunosuppressant medications is an important risk factor for graft dysfunction. To evaluate the effectiveness of adherence-enhancing interventions, we reviewed adherence intervention studies in solid organ transplant recipients (all ages). Using the following databases: PsycINFO, PubMed, Scopus, and ScienceDirect, we identified 41 eligible studies. Only three non-randomized trials showed a possible positive effect on objective indicators of transplant outcomes (such as rejection, liver enzyme levels, kidney function). None of the 21 RCTs showed an improvement in transplant outcomes. Three studies showed a higher rate of adverse events in the intervention group as compared with controls, although this may be related to ascertainment bias. Improvement in adherence as measured indirectly (eg, with electronic monitoring devices) was not aligned with effects on transplant outcomes. We conclude that adherence interventions, to date, have largely been ineffective in improving transplant outcomes. To improve this track record, intervention efforts may wish to concentrate on non-adherent patients (rather than use convenience sampling, which excludes many of the patients who need the intervention), use direct measures of adherence to guide the interventions, and employ strategies that are intensive and yet engaging enough to ensure that non-adherent patients are able to participate.

Pediatric Heart Transplantation: Transitioning to Adult Care (TRANSIT): Baseline Findings

Young adult solid organ transplant recipients who transfer from pediatric to adult care experience poor outcomes related to decreased adherence to the medical regimen. Our pilot trial for young adults who had heart transplant (HT) who transfer to adult care tests an intervention focused on increasing HT knowledge, self-management and self-advocacy skills, and enhancing support, as compared to usual care. We report baseline findings between groups regarding (1) patient-level outcomes and (2) components of the intervention. From 3/14 to 9/16, 88 subjects enrolled and randomized to intervention (n = 43) or usual care (n = 45) at six pediatric HT centers. Patient self-report questionnaires and medical records data were collected at baseline, and 3 and 6 months after transfer. For this report, baseline findings (at enrollment and prior to transfer to adult care) were analyzed using Chi-square and t-tests. Level of significance was p < 0.05. Baseline demographics were similar in the intervention and usual care arms: age 21.3 ± 3.2 vs 21.5 ± 3.3 years and female 44% vs 49%, respectively. At baseline, there were no differences between intervention and usual care for use of tacrolimus (70 vs 62%); tacrolimus level (mean ± SD = 6.5 ± 2.3 ng/ml vs 5.6 ± 2.3 ng/ml); average of the within patient standard deviation of the baseline mean tacrolimus levels (1.6 vs 1.3); and adherence to the medical regimen [3.6 ± 0.4 vs 3.5 ± 0.5 (1 = hardly ever to 4 = all of the time)], respectively. At baseline, both groups had a modest amount of HT knowledge, were learning self-management and self-advocacy, and perceived they were adequately supported. Baseline findings indicate that transitioning HT recipients lack essential knowledge about HT and have incomplete self-management and self-advocacy skills.

Variability index of tacrolimus serum levels in pediatric liver transplant recipients younger than 12 years: Non-adherence or risk of non-adherence?

MLVI has been used to assess adherence. To determine the MLVI in children <12 years of age at transplantation and to identify demographic correlates and consequences for the graft. This is a retrospective study of 50 outpatients (4.0 ± 3.5 years), at least 13-month post-liver transplantation. The outcomes evaluated were MLVI, ALT > 60 IU/L, ACR, death, and graft loss. We analyzed demographic and socioeconomic characteristics, indication for transplantation, and type of donor. Student's t test and the chi-square test were used. Statistical significance was set at P ≤ .05. Seventy-two percent were infants or preschoolers, 62% biliary atresia. Seventy-four percent of the mothers had middle-school education, and 54% of the families had an income ≤3632.4 US$/y. Twenty-two (44%) patients had a MLVI ≥ 2 SD; this was more prevalent in families with higher incomes (P = .045). ALT levels > 60 IU/L were more common in MLVI ≥ 2 SD group (P = .035). ACR episodes were similar between groups (P = 1.000). No patient died or lost the graft. MLVI ≥ 2 SD may be an indicator of the risk of medication non-adherence.

The Medication Level Variability Index (MLVI) Predicts Poor Liver Transplant Outcomes: A Prospective Multi-Site Study

Nonadherence to immunosuppressant medications is a leading cause of poor long-term outcomes in transplant recipients. The Medication Level Variability Index (MLVI) provides a vehicle for transplant outcome risk-stratification through continuous assessment of adherence. The MALT (Medication Adherence in children who had a Liver Transplant) prospective multi-site study evaluated whether MLVI predicts late acute rejection (LAR). Four hundred pediatric (1-17-year-old) liver transplant recipients were enrolled and followed for 2 years. The a-priori hypothesis was that a higher MLVI predicts LAR. Predefined secondary analyses evaluated other outcomes such as liver enzyme levels, and sensitivity analyses compared adolescents to pre-adolescents. In the primary analysis sample of 379 participants, a higher prerejection MLVI predicted LAR (mean prerejection MLVI with LAR: 2.4 [3.6 standard deviation] versus without LAR, 1.6 [1.1]; p = 0.026). Fifty-three percent of the adolescents with MLVI>2 in year 1 had LAR by the end of year 2, as compared with 6% of those with year 1 MLVI≤2. A higher MLVI was significantly associated with all secondary outcomes. MLVI, a marker of medication adherence that uses clinically derived information, predicts LAR in pediatric liver transplant recipients.

Longitudinal study on the use of dried blood spots for home monitoring in children after kidney transplantation

The use of DBSs for home monitoring has been limited due to unsatisfactory blood sampling and analytical difficulties. The aim of this longitudinal feasibility trial was to assess the utility of DBS to monitor TAC and Cr at home in transplant recipients. A total of 30 participants (2-21 years, mean±SD, 13.6±5.4 year) were enrolled over 12 months. Eighteen were males. Monthly DBS samples were obtained at home and mailed to the central laboratory for analysis of TAC and Cr. Nineteen patients completed the study, and 216 cards were received in the laboratory from a total of 279 cards expected, with 416/519 (80%) blood spots being suitable for analysis. We found a high correlation between blood TAC and Cr levels by DBS and the clinical laboratory, R² =.81 and .95, respectively. Fifteen parents and 15 youth completed measures of satisfaction with and preference for DBS testing. All but one parent/caregiver and youth reported satisfaction and preference for this method of testing over laboratory blood draws. We conclude that home DBS monitoring is a feasible method to monitor TAC and Cr in pediatric transplant recipients.

Medication adherence and rejection rates in older vs younger adult liver transplant recipients

A growing number of older adults are undergoing liver transplantation (LT) in the United States. In some settings, it is thought that adherence declines with age. This retrospective study examined adherence and clinical outcomes in older vs younger adult LT recipients. Medical records of adult LT recipients from 2009 to 2012 from a single urban center were reviewed. The medication level variability index (MLVI) was the predefined primary outcome, with nonadherence defined as MLVI >2.5. The secondary outcome was incidence of rejection. Outcomes were evaluated starting 1 year post-LT until 2015. A total of 42 of 248 patients were ≥65 at transplant. Older adults had significantly better adherence than younger ones (65%≥65 were adherent vs 42% younger adults; chi-square two-tailed P=.02). Survival analyses of rejection between age groups censored by time since transplant showed no difference among the four age groups (χ² =0.84, P=.84). Older age was not found to be a risk factor for reduced adherence or graft rejection in patients surviving at least 1 year post-LT.

Patient-reported non-adherence and immunosuppressant trough levels are associated with rejection after renal transplantation

Background

Different measures of non-adherence to immunosuppressant (IS) medication have been found to be associated with rejection episodes after successful transplantation. The aim of the current study was to investigate whether graft rejection after renal transplantation is associated with patient-reported IS medication non-adherence and IS trough level variables (IS trough level variability and percentage of sub-therapeutic IS trough levels).

Methods

Patient-reported non-adherence, IS trough level variability, percentage of sub-therapeutic IS trough levels, and acute biopsy-proven late allograft rejections were assessed in 267 adult renal transplant recipients who were ≥12 months post-transplantation.

Results

The rate of rejection was 13.5%. IS trough level variability, percentage of sub-therapeutic IS trough levels as well as patient-reported non-adherence were all significantly and positively associated with rejection, but not with each other. Logistic regression analyses revealed that only the percentage of sub-therapeutic IS trough levels and age at transplantation remained significantly associated with rejection.

Conclusions

Particularly, the percentage of sub-therapeutic IS trough levels is associated with acute rejections after kidney transplantation whereas IS trough level variability and patient-reported non-adherence seem to be of subordinate importance. Patient-reported non-adherence and IS trough level variables were not correlated; thus, non-adherence should always be measured in a multi-methodological approach. Further research concerning the best combination of non-adherence measures is needed.

Development and field testing of Teen Pocket PATH(®), a mobile health application to improve medication adherence in adolescent solid organ recipients

Applying principles of user-centered design, we iteratively developed and tested the prototype of TPP, an mHealth application to promote medication adherence and enhance communication about medication management between adolescents and primary caregivers. A purposive sample of seven adolescent solid organ transplant recipients who were ≥ one yr post-transplant and their primary caregivers participated. Participants completed up to three face-to-face laboratory usability sessions, a 6-week field test, and a debriefing session. Primary caregivers participated in an additional usability telephone session. Participants completed usability and satisfaction measures. Sample included liver (n = 4), heart (n = 2), and lung (n = 1) recipients aged 11-18 yr (57% were female, 86% were Caucasian), and nine primary caregivers aged 42-61 yr (88.9% were parents, 88% were female, 88% were Caucasian). Ninety percent of the adolescents endorsed the graphs or logs of missed/late medication dosing as useful and 100% endorsed the remaining features (e.g., medication list, dose time reminders/warnings) as useful. All adolescents expressed interest in using TPP for monitoring medications and satisfaction with the automatic messaging between adolescent and caregiver versions of the application. Adolescents unanimously found TPP easy to use. TPP shows promise as an mHealth adherence tool.

Fingerprints of transplant tolerance suggest opportunities for immunosuppression minimization

HLA incompatible organ transplant tolerance is the holy grail of transplantation. Stable engraftment of an HLA mismatched allograft and life-long tolerance induction, though feasible in highly selected cohorts with depletional protocols, is not ready for generalized application to the entire transplant recipient pool. It has thus been important to harness biomarkers that can uncover mechanisms and tools for monitoring HLA mismatched recipients that develop a state of operational tolerance, during accidental immunosuppression withdrawal secondary to problems of over-immunosuppression (infection or malignancy) or toxicity (mostly cosmetic or cardiovascular). A restricted and unpredictable group of patients can demonstrate a clinical state of operational tolerance, manifested by state of stable graft function of a graft with HLA mismatches between recipient and donor, intact immune responses to third party antigens and no measurable immunosuppression. These patients have served as the basis for the discovery of clinically correlative biomarkers, in distal biofluids (mainly blood), that can define the existing state of operational clinical tolerance. Operationally tolerant patients are rare, as withdrawal of immunosuppression most often results in rejection and graft loss. Nevertheless, operationally tolerant kidney, liver and heart allograft recipients have been reported. The presence of similar biomarker signature profiles in HLA mismatched transplant recipients on immunosuppression, suggests the feasibility of utilizing these biomarkers for educated immunosuppression minimization with a view to retaining immunological quiescence, while reducing the maintenance immunosuppression burden to a "safe" alloimmune threshold. Though clinical operational tolerance is rare, as immunosuppression cessation most often results in increased alloimmunity and rejection, the biomarker profile studies that have harnessed whole genome profiling suggest that the frequency of this state may be ~8% in kidney allograft recipients, and even more frequent in pediatric recipients and in liver transplantation: 25% in adult liver allograft recipients and ~60% in pediatric liver allograft recipients. In this review we discuss putative molecular mechanisms, cellular players and correlative biomarkers that have been developed through clinically associative studies of tolerant and non-tolerant patients. Through mechanisms of carefully constructed and monitored randomized, prospective clinical trials, the transplant community stands at the cusp of improved quality of recipient life through educated immunosuppression minimization.

Transitional Care and Adherence of Adolescents and Young Adults After Kidney Transplantation in Germany and Austria: A Binational Observatory Census Within the TRANSNephro Trial

Transition from child to adult-oriented care is widely regarded a challenging period for young people with kidney transplants and is associated with a high risk of graft failure. We analyzed the existing transition structures in Germany and Austria using a questionnaire and retrospective data of 119 patients transferred in 2011 to 2012. Most centers (73%) confirmed agreements on the transition procedure. Patients' age at transfer was subject to regulation in 73% (18 years). Median age at transition was 18.3 years (16.5-36.7). Median serum creatinine increased from 123 to 132 μmol/L over the 12 month observation period before transfer (P = 0.002). A total of 25/119 patients showed increased creatinine ≥ 20% just before transfer. Biopsy proven rejection was found in 10/119 patients. Three patients lost their graft due to chronic graft nephropathy.Mean coefficient of variation (CoV%) of immunosuppression levels was 0.20 ± 0.1. Increased creatinine levels ≥ 20% just before transfer were less frequently seen in patients with CoV < 0.20 (P = 0.007). The majority of pediatric nephrology centers have internal agreements on transitional care. More than half of the patients had CoV of immunosuppression trough levels consistent with good adherence. Although, 20% of the patients showed increase in serum creatinine close to transfer.

Can Transition to Adult Care for Transplant Recipients Be Improved by Intensified Services While Patients are Still in Pediatrics?

Context—

Transferring out of pediatrics is a vulnerable time for transplant recipients. Use of a transition coordinator before and after transfer improves outcomes, although it is unclear whether placing a transition coordinator in pediatrics alone is beneficial.

Objective—

To determine if incorporating a transition coordinator in pediatrics only is associated with stable outcomes for kidney transplant recipients.

Design—

A retrospective chart review was conducted on outcomes for kidney transplant recipients who shifted service location between 2008 and 2012.

Setting—

A pediatric and adult transplant unit.

Patients—

Twenty-two patients transferred during the study period.

Intervention—

Twelve patients received more intensified preparation from the team's social worker, whose role was aligned with a transition coordinator position; 10 patients received standard care.

Main Outcome Measures—

The primary outcome was medication adherence, using a validated measure, standard deviations of tacrolimus blood levels. A standard deviation greater than 2.5 has been established as a threshold associated with poor outcomes such as rejection. Standard deviation of tacrolimus levels was compared for 1 year before and 1 year after transfer.

Results—

Medication adherence worsened from 1 year before (2.03 [SD, 0.75]) to 1 year after transfer (2.95 [SD, 1.38]; t = −3.07, P = .007). A repeated-measures analysis of variance indicated that this pattern was the same for patients who did and patients who did not receive intensified services in pediatrics ( F1,16 = 1.07, P = .32).

Assessing allocation of responsibility for health management in pediatric liver transplant recipients

Given the increased risk for non-adherence and poor health outcomes in late adolescence, there is a need for better methods to evaluate and improve the transition process as adolescent patients are prepared to be independent adults. This study assessed the psychometrics and concurrent validity of a newly developed measure of AoR for health management in pediatric liver transplant patients. A total of 48 patients and 37 parents completed a 13-item measure of AoR. We performed an exploratory PCA on survey results and used component scores to assess the relationship between AoR and age, age at transplant, adherence, and health outcomes. Two primary components were identified: communication with the healthcare system and self-management tasks. Parent perception of adolescent responsibility for tasks related to communicating with the healthcare system was correlated, in younger patients, with increased non-adherence while responsibility for tasks related to self-management was correlated, in older patients, with decreased non-adherence. These results support AoR as a two-domain construct, and they provide targets for monitoring and intervention as adolescent patients advance toward transfer.

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

Nonadherence to immunosuppressants may play a role in late rejection in liver transplant recipients. In children, emerging data suggest that adherence can be measured through the computation of the standard deviation (SD) of consecutive blood levels of tacrolimus, which results in a number that reflects the degree of variability between individual measures: the medication level variability index (MLVI). A higher MLVI value means erratic immunosuppression, likely due to less adherence. Data on this method are limited for adults. We obtained data from the medical charts of 150 randomly selected adult recipients. The MLVI was significantly higher for patients who had biopsy-confirmed rejection (mean MLVI = 3.8, SD = 3.2) versus the rest of the cohort (mean MLVI = 2.3, SD = 1.5, P = 0.003), and it was significantly higher for patients who suffered rejection versus patients whose biopsy sample was not read as rejection (mean MLVI = 2.6, SD = 1.6, P = 0.008). The MLVI was associated with rejection and predicted its occurrence. A threshold MLVI of 2.0 resulted in 77% sensitivity and 60% specificity in predicting rejection; a threshold of 1.8 resulted in a sensitivity of 92% and a specificity of 48%. The area under the curve in a receiver operating characteristic curve analysis was 0.71 (95% CI = 0.61-0.81). In conclusion, the MLVI is associated with and can predict rejection, possibly related to nonadherence, in adult liver transplant recipients.

The adolescent liver transplant patient

The rapid development of new diagnostic tests and improved therapy, especially the success of liver transplantation, has changed the outcome for children with liver disease, many of whom survive into adolescence without liver transplantation. The indications for transplantation in adolescence are similar to pediatric indications and reflect the medical advances made in this specialty that allow later transplantation. These young people need a different approach to management that involves consideration of their physical and psychological stage of development. A focused approach to their eventual transition to adult care is essential for long-term survival and quality of life.

An evaluation of the pharmacokinetics of methylphenidate for the treatment of attention-deficit/ hyperactivity disorder

INTRODUCTION

Methylphenidate (MPH) plays a principal role in the multimodal treatment of attention-deficit/hyperactivity disorder (ADHD). Controlled studies have demonstrated an effective reduction in the core symptoms of the disorder following MPH therapy, although long-term studies also demonstrate that the therapeutic benefits dissipate in the absence of combined psychosocial interventions.

AREAS COVERED

This review article focuses on the pharmacological characteristics of MPH, examining its effects on brain metabolism and the neurotransmitter system. Neuropsychological and clinical effects of different immediate and extended release MPH formulations are discussed to aid clinicians in choosing the appropriate formulation. The drug's addictive potency and abuse potential is also discussed. Data came from a literature search of relevant studies performed using the PubMed database up to June 2013.

EXPERT OPINION

MPH is effective in the treatment of the core symptoms of ADHD. Considerable clinical expertise is required to identify an individually well-adapted dosage which will produce the optimal clinical effects with potential side effects minimized. Due to low adherence to medication, especially in adolescents, motivation to treatment and attentive clinical monitoring is mandatory, as is the consideration of risks of abuse or the presence of a comorbid addictive disorder.

Time-dependent variability in tacrolimus trough blood levels is a risk factor for late kidney transplant failure

Wide variations in tacrolimus levels have been identified as a risk factor for inferior kidney allograft survival but past studies have not properly accounted for the dynamic nature of drug exposure over time. Here we evaluated whether time-varying exposure to tacrolimus increases the risk of long-term adverse outcomes in a retrospective cohort study in adult kidney transplant recipients on tacrolimus-based immunosuppression. Time-dependent Cox proportional hazards models were used to examine the association between the standard deviation of tacrolimus levels (TacSD) starting at 1-year post-transplant and the composite end point of late allograft rejection, transplant glomerulopathy, or total graft loss (including death). Among 356 patients, there was a significant 27% increase in the adjusted hazard of the composite end point for every 1-unit increase in TacSD (hazard ratio 1.27 (95% confidence interval 1.03, 1.56)). There was also a graded increase in the relative hazard for the composite end point by TacSD threshold (hazard ratios 1.33, 1.50, 1.84, and 2.56 for TacSD 1.5, 2, 2.5, and 3, respectively). The results were similar for total graft loss and the composite end point excluding death. Thus, increased time-dependent TacSD may be an independent risk factor for adverse kidney transplant outcomes. TacSD may serve as a monitoring tool to identify high-risk patients. Whether interventions to decrease TacSD will improve outcomes requires further study.

Strangers headed to a strange land? A pilot study of using a transition coordinator to improve transfer from pediatric to adult services

OBJECTIVE

To compare the impact of a transition coordinator on outcomes for pediatric liver transplant recipients vs a historical comparison group.

STUDY DESIGN

To examine the utility of a transition coordinator, medication adherence, as measured by SDs of tacrolimus blood levels (Tacrolimus SD), was compared between the "transition coordinator group" (20 transplant recipients transferred between 2007 and 2012) and comparison group for 1 year before and after transfer. Measures of health care management, quality of life, and acceptability were administered to the transition coordinator group as well.

RESULTS

A repeated measures ANOVA was used to compare adherence values between the transition coordinator group and the comparison group. During the year before transfer, for the transition coordinator group, Tacrolimus SD was 1.98 (SD = 1.05) vs 3.25 (SD = 1.19) for comparison patients, F(1,25) = 4.77, P = .04. After transfer, levels remained stable for the transition coordinator group, Tacrolimus SD = 1.88 (SD = 1.57), but increased for comparison patients, Tacrolimus SD = 4.36 (SD = 0.99), F(1,25) = 6.99, P = .01. Psychosocial outcomes remained stable during the transfer period and acceptability was high.

CONCLUSIONS

Our findings, although limited by a small sample size, suggest that a transition coordinator is a promising method to improve this process.

Managing bronchiolitis obliterans syndrome (BOS) and chronic lung allograft dysfunction (CLAD) in children: what does the future hold?

The success of pediatric lung transplantation continues to be limited by long-term graft dysfunction. Historically this has been characterized as an obstructive spirometric defect in the form of the bronchiolitis obliterans syndrome (BOS). It is recognized, however, that this does not reflect many of the other acknowledged etiologies of chronic lung dysfunction-noting it is the sum of the parts that contribute to respiratory morbidity and mortality after transplant. The term chronic lung allograft dysfunction (CLAD) has been coined to reflect these other entities and, in particular, a group of relatively recently described lung disorders called the restrictive allograft syndrome (RAS). RAS is characterized by a restrictive spirometric defect. Although these entities have not yet been studied in a pediatric setting their association with poor compliance, antibody-mediated rejection (AMR), and post-infectious lung damage (particularly viral) warrants attention by pediatric lung transplant teams. Current therapy for the BOS subset of CLAD is otherwise limited to changing immunosuppressants and avoiding excessive infectious risk by avoiding over-immunosuppression. Long-term macrolide therapy in lung transplantation is not of proven efficacy. Reviewing previous BOS studies to explore restrictive spirometric cases and joint projects via groups like the International Pediatric Lung Transplant Collaborative will be the way forward to solve this pressing problem.