Once daily tacrolimus conversion in lung transplantation: A prospective study on safety and medication adherence

Impact of tacrolimus vs cyclosporine on chronic lung allograft dysfunction incidence and allograft survival in the International Society of Heart and Lung Transplantation registry

BACKGROUND

The ScanCLAD study reported a lower incidence of chronic lung allograft dysfunction (CLAD) with the use of once-daily tacrolimus vs twice-daily cyclosporine. Using the International Society for Heart and Lung Transplantation (ISHLT) Thoracic Organ Transplant (TTX) Registry data, we evaluated the hypothesis that tacrolimus is superior to cyclosporine in real-world clinical practice.

METHODS

This study is a retrospective cohort study of adult lung transplant recipients in the ISHLT registry from January 1, 2000, to June 30, 2018, with known CLAD status. The primary exposure variable was patients' maintenance calcineurin inhibitor (CNI) regimen captured at posttransplant discharge. The primary outcome variables were time to CLAD development (with death/retransplantation analyzed as a competing risk) and allograft survival (i.e., time to death/retransplant).

RESULTS

Of the 57,403 adult lung transplant recipients in the registry, 22,222 had both CNI and CLAD data available. Of these, 19,698 (88.6%) received tacrolimus immediate release (IR), 2,477 (11.2%) received cyclosporine, and 47 (0.2%) received tacrolimus extended release (XR) for maintenance CNI. Receiving cyclosporine for maintenance immunosuppression (vs tacrolimus IR) was associated with an increased risk of developing CLAD (hazard ratio [HR] 1.16, 95% confidence interval [CI] 1.08-1.23, p < 0.001) and with an increased overall risk for death/retransplant (HR 1.16, 95% CI 1.09-1.23, p < 0.001). Receiving tacrolimus XR vs tacrolimus IR was not associated with differences in long-term posttransplant outcomes, although these analyses were limited by a small sample size.

CONCLUSIONS

Patients receiving cyclosporine vs tacrolimus IR for maintenance calcineurin inhibition had an increased risk of CLAD and decreased overall allograft survival in the ISHLT TTX registry.

Pharmacokinetic Boosting of Calcineurin Inhibitors in Transplantation: Pros, Cons, and Perspectives

ABSTRACT

The concept of pharmacokinetic (PK) boosting of calcineurin inhibitors (CNI) emerged after the FDA approval of cyclosporine-A. Several studies followed, and the proof of concept was well established by the late 1990s. This also continued for the next blockbuster immunosuppressant, tacrolimus. The driver for such research was an endeavor to save costs, as both drugs were expensive due to patent protection. Two CYP inhibitors, ketoconazole and diltiazem, have been extensively studied in this context and continue to be prescribed off-label along with the CNI. It has been observed that using ketoconazole reduces the dose requirement of tacrolimus by about 50% and 30% with diltiazem, which is in conformity with their pharmacological actions. Off-label co-prescription of these drugs with CNI is often encountered in low and middle-income countries. The foremost reason cited is economic. This article collates the evidence from the clinical studies that evaluate the PK-boosting effects of CNI and also reviews the gaps in the current evidence base. The current knowledge prevents the transplant community from making meaningful inferences about the risks and benefits of such strategies. Although the PK-boosting strategy can lead to serious adverse events, emerging evidence suggests that it may be advantageous for individuals with high CNI dose requirements. Hence, PK boosting may be an unmet need in the therapeutics of CNI. Nevertheless, there are several unanswered questions surrounding such use, and therefore, this merits testing in well-designed clinical studies. Moreover, drugs with better safer profiles and a history of successful PK boosting may be considered for evaluation with CNI.

Review of Association between Urinary Tract Infections and Immunosuppressive Drugs after Heart Transplantation

Management of infections in heart transplant recipients is complex and crucial. In this population, there is a need for a better understanding of immunosuppressive trough levels (C0), infectious complications, and urinary tract infections (UTIs). The purpose of this review was to understand the association between immunosuppressive trough levels and UTIs after heart transplantation. A review of scientific literature (n= 100) was conducted based on the topic of interest by searching PUBMED.Gov (https://pubmed.ncbi.nlm.nih.gov/), Web of Science, and Scopus. The analysis of bacterial pulmonary infection required the occurrence of new or deteriorating pulmonary infiltrates and the development of organisms in cultures of sputum specimens. The diagnosis of UTIs was based on the result of related signs, pyuria, and a positive urine culture. The incidence of UTIs was reported as 0.07 episodes/1000 regarding heart transplantation days. An eightfold increase in the rate of rejection was noted in heart transplant recipients with higher variability in tacrolimus C0. There are associations between C0 of immunosuppressive drugs and clinical presentation of infection complications. Recipients with a low metabolism of immunosuppressive drugs are more susceptible to infectious complications. Attention to the biology of herpes viruses, Escherichia coli, Enterococcus spp., Pseudomonas aeruginosa, and Staphylococcus saprophyticus after heart transplantation are important, in which some of them are the most common pathogens responsible for UTIs. Pneumocystis and cytomegalovirus affect all transplant recipients. Pneumonia due to bacterial, viral, protozoa, and fungal infections, in addition to UTIs, are more specific reported types of infections in heart transplant recipients. Bacterial infections produced by extensively drug-resistant Enterobacteriaceae, vancomycin-resistant enterococci, and non-fermenting gramnegative bacteria were reported to increase after transplantation.

Factors and interventions affecting tacrolimus intrapatient variability: A systematic review and meta-analysis

BACKGROUNDS

Tacrolimus is a cornerstone of posttransplantation immunosuppressive regimens. Despite routine monitoring, the efficacy of its trough concentrations in reflecting drug concentration fluctuations is limited. Intrapatient variability (IPV) emerges as a novel monitoring marker for predicting clinical outcomes. However, understanding the factors affecting IPV and assessing interventions to address it remain enigmatic, posing a conundrum in clinical management.

OBJECTIVES

This systematic review aimed to investigate a spectrum of factors affecting IPV and assess the effect of strategic interventions, thereby charting a course for enhanced clinical stewardship.

METHODS

We electronically searched of PubMed, Embase, and the Cochrane Library databases for studies investigating factors and interventions affecting IPV up to October 2023. Two reviewers independently screened literature, extracted data, and assessed quality, using RevMan 5.4.1 software for meta-analysis.

RESULTS

A total of 15 randomized controlled trials (RCTs), 34 cohort studies, and 20 self-controlled studies were included. The results indicated that IPV was significantly higher in cytochrome P450 3A5 (CYP3A5) expressers, nonadherent patients, patients taking proton pump inhibitors or statins, and Black or African American recipients, whereas recipients consuming extended-release formulation exhibited lower IPV. Additionally, the participation of pharmacists had a positive effect on improving IPV.

CONCLUSIONS

Factors affecting IPV encompassed genotype, formulation, adherence, drug combinations, and ethnicity, with each factor exerting varying degrees of effect. Identifying these factors was crucial for developing targeted intervention strategies. While the participation of pharmacists held a promise in improving IPV, further investigation of interventions such as mobile technology, educational measures to enhance adherence, and personalized dosing regimens was warranted.

Optimizing the initial tacrolimus dosage in Chinese children with lung transplantation within normal hematocrit levels

Background

The appropriate initial dosage of tacrolimus is undefined in Chinese pediatric lung transplant patients with normal hematocrit values. The purpose of this study is to optimize the initial dose of tacrolimus in Chinese children who are undergoing lung transplantation and have normal hematocrit levels.

Methods

The present study is based on a published population pharmacokinetic model of tacrolimus in lung transplant patients and uses the Monte Carlo simulation to optimize the initial tacrolimus dosage in Chinese children with lung transplantation within normal hematocrit levels.

Results

Within normal hematocrit levels, for children with lung transplantation who do not carry the CYP3A5*1 gene and have no coadministration with voriconazole, it is recommended to administer tacrolimus at a dosage of 0.02 mg/kg/day, divided into two doses, for children weighing 10-32 kg, and a dosage of 0.03 mg/kg/day, also divided into two doses, for children weighing 32-40 kg. For children with lung transplantation who carry the CYP3A5*1 gene and have no coadministration with voriconazole, tacrolimus dosages of 0.02, 0.03, and 0.04 mg/kg/day split into two doses are recommended for children weighing 10-15, 15-32, and 32-40 kg, respectively. For children with lung transplantation who do not carry the CYP3A5*1 gene and have coadministration with voriconazole, tacrolimus dosages of 0.01 and 0.02 mg/kg/day split into two doses are recommended for children weighing 10-17 and 17-40 kg, respectively. For children with lung transplantation who carry the CYP3A5*1 gene and have coadministration with voriconazole, a tacrolimus dosage of 0.02 mg/kg/day split into two doses is recommended for children weighing 10-40 kg.

Conclusions

It is the first time to optimize the initial dosage of tacrolimus in Chinese children undergoing lung transplantation within normal hematocrit.

Psychometric Properties of the BAASIS: A Meta-analysis of Individual Participant Data

BACKGROUND

Nonadherence to immunosuppressives, a risk factor for poor posttransplant outcomes, can be assessed by self-report using the Basel Assessment of Adherence to Immunosuppressive Medications Scale (BAASIS). Available in written and interview versions, and previously validated on content, the BAASIS is widely used in research and clinical practice. The aim of this study was to investigate its psychometric properties.

METHODS

Using a literature search and our BAASIS database, this meta-analysis identified completed studies in adult transplant recipients whose data were usable to examine the BAASIS' reliability and 3 validity aspects: (1) relationships with other variables (electronic monitoring, other self-report scales, tacrolimus blood-level variability, collateral report, depressive symptoms, psycho-behavioral constructs, and interventions); (2) response processes; and (3) internal structure. Testing used random-effects logistic regressions.

RESULTS

Our sample included 12 109 graft recipients from 26 studies. Of these 26, a total of 20 provided individual participant data. Evidence of the BAASIS' stability over time supports its reliability. Validity testing of relationships with other variables showed that BAASIS-assessed nonadherence was significantly associated with the selected variables: electronically monitored nonadherence ( P < 0.03), other self- and collaterally-reported nonadherence ( P < 0.001), higher variability in tacrolimus concentrations ( P = 0.02), higher barriers ( P < 0.001), lower self-efficacy ( P < 0.001), lower intention ( P < 0.001), and higher worries ( P = 0.02). Nonadherence also decreased after regimen change interventions ( P = 0.03). Response process evaluation indicated good readability and slightly higher nonadherence with the written version. Structurally, items on taking and timing shared variability.

CONCLUSIONS

The BAASIS shows good validity and reliability as a self-report instrument to assess medication nonadherence in transplantation.

Efficacy of Prolonged-release Tacrolimus After Conversion From Immediate-release Tacrolimus in Kidney Transplantation: A Retrospective Analysis of Long-term Outcomes From the ADMIRAD Study

Prolonged-release tacrolimus (PRT) may offer improved outcomes after kidney transplantation compared with immediate-release tacrolimus (IRT). However, data on outcomes beyond 5-y posttransplantation are lacking.

Methods

A retrospective, noninterventional chart review study examined long-term graft survival in adult kidney transplant participants in the Adherence Measurement in Stable Renal Transplant Patients Following Conversion From Prograf to Advagraf (ADMIRAD) clinical trial at 4 Belgian sites. Patients were randomized to receive once-daily PRT or twice-daily IRT for 6 mo, followed by treatment as per real-world clinical practice. Data were collected retrospectively from randomization day until December 31, 2018. Primary endpoints included efficacy failure, defined as a composite endpoint of graft loss, biopsy-confirmed acute rejection, and graft dysfunction. Secondary endpoints included overall patient survival and course of kidney function.

Results

This analysis included 78.5% of patients from ADMIRAD (n = 108 PRT; n = 64 IRT). The Kaplan-Meier survival rate without efficacy failure from randomization to year 5 was 0.741 (95% confidence interval [CI]: 0.647, 0.813) for the PRT group (n = 80), and 0.667 (95% CI: 0.536, 0.768) for the IRT group (n = 42) and remained higher for PRT throughout 10 y follow-up (P = 0.041). The Kaplan-Meier estimate of overall survival from the time of last transplant was 0.981 (95% CI: 0.928, 0.995) and 0.880 (95% CI: 0.802, 0.928) at 5 and 10 y in the PRT group. Kidney function parameters and tacrolimus trough levels remained stable over the follow-up period.

Conclusions

Patients in the ADMIRAD study who received PRT for up to 10 y had improved long-term outcomes compared with patients receiving IRT, with a consistent effect on both graft and patient survival.

A Systematic Review of Adherence to Immunosuppression among Pediatric Heart Transplant Patients

After pediatric heart transplant, commitment to lifelong immunosuppression is crucial to maintaining graft health. However, a review of the current literature surrounding adherence to immunosuppression in pediatric heart transplant patients is lacking. This systematic review aims to summarize the current landscape of adherence to immunosuppression in pediatric heart transplant patients. We conducted searches in PubMed MEDLINE, Embase, CENTRAL register of Controlled Trials (Wiley), and Scopus, from inception to March 2020. Studies were eligible if they outlined an aspect of adherence to immunosuppression and the measurement of adherence was performed with an objective or otherwise validated measure of adherence (e.g., drug levels, adherence questionnaires). The titles/abstracts of 880 articles were reviewed. After initial screening, 106 articles underwent full text review. As such, 14 articles were included in the final review. Baseline adherence estimates varied greatly, with most values between 40% and 70%. Nonadherence to immunosuppression is associated with worse outcomes (rejection, hospitalization, mortality), impaired quality of life, and mental health concerns in pediatric heart transplant patients. As nonadherence to immunosuppression is common and associated with worse outcomes, there is a need for further development and evaluation of interventions in this space.