Artificial Neural Network Analysis of Determinants of Tacrolimus Pharmacokinetics in Liver Transplant Recipients

BACKGROUND

The efficacy and toxicity of tacrolimus are closely related to its trough blood concentrations. Identifying the influencing factors of pharmacokinetics of tacrolimus in the early postoperative period is conducive to the optimization of the individualized tacrolimus administration protocol and to help liver transplant (LT) recipients achieve the target blood concentrations.

OBJECTIVE

This study aimed to develop an artificial neural network (ANN) for predicting the blood concentration of tacrolimus soon after liver transplantation and for identifying determinants of the concentration based on Shapley additive explanation (SHAP).

METHODS

In this retrospective study, we enrolled 31 recipients who were first treated with liver transplantation from the Department of Liver Transplantation and Hepatic Surgery, the First Affiliated Hospital of Shandong First Medical University (Shandong Provincial Qianfoshan Hospital) from November 2020 to May 2021. The basic information, biochemical indexes, use of concomitant drugs, and genetic factors of organ donors and recipients were used for the ANN model inputs, and the output was the steady-state trough concentration (C0) of tacrolimus after oral administration in LT recipients. The ANN model was established to predict C0 of tacrolimus, SHAP was applied to the trained model, and the SHAP value of each input was calculated to analyze quantitatively the influencing factors for the output C0.

RESULTS

A back-propagation ANN model with 3 hidden layers was established using deep learning. The mean prediction error was 0.27 ± 0.75 ng/mL; mean absolute error, 0.60 ± 0.52 ng/mL; correlation coefficient between predicted and actual C0 values, 0.9677; and absolute prediction error of all blood concentrations obtained by the ANN model, ≤3.0 ng/mL. The results indicated that the following factors had the most significant effect on C0: age, daily drug dose, genotype at CYP3A5 polymorphism rs776746 in both recipient and donor, and concomitant use of caspofungin. The predicted C0 value of tacrolimus in LT recipients increased in a dose-dependent manner when the daily dose exceeded 3 mg, whereas it decreased with age when LT recipients were older than 48 years. The predicted C0 was higher when recipients and donors had the genotype CYP3A5*3*3 than when they had the genotype CYP3A5*1. The predicted C0 value also increased with the use of caspofungin or Wuzhi capsule.

CONCLUSION AND RELEVANCE

The established ANN model can be used to predict the C0 value of tacrolimus in LT recipients with high accuracy and good predictive ability, serving as a reference for personalized treatment in the early stage after liver transplantation.

Roflumilast foam (Zoryve) for seborrheic dermatitis

The FDA has approved a 0.3% foam formulation of the phosphodiesterase-4 (PDE4) inhibitor roflumilast (Zoryve – Arcutis) for topical treatment of seborrheic dermatitis in patients ≥9 years old. Roflumilast is the first PDE4 inhibitor to be approved in the US for this indication.

Adverse events related to drug-drug interactions in COVID-19 patients. A persistent concern in the post-pandemic era: a systematic review

INTRODUCTION

Since COVID-19 patients are often polytreated, monitoring drug-drug interaction (DDIs) is necessary. We evaluated whether drugs used after the second COVID-19 pandemic wave were associated with DDI-related adverse events and the role of drug interaction checkers in identifying them.

METHODS

The study (PROSPERO-ID: CRD42024507634) included: 1) consulting the drug interaction checkers Drugs.com, Liverpool COVID-19 Interactions, LexiComp, Medscape, and Micromedex; 2) systematic review; 3) reviewed studies analysis; 4) evaluating drug interaction checkers potential to anticipate DDI-related adverse events.The systematic review was performed searching PubMed, Scopus, ScienceDirect, and Cochrane databases from 1 March 2022 to 11 November 2023. Observational studies, and clinical trials were included. Article without reporting direct association between DDIs and adverse events were excluded. The risk of bias was assessed by Newcastle-Ottawa scale.

RESULTS

The most frequent DDIs involved nirmatrelvir/ritonavir (N/R) and fluvoxamine. Fifteen studies, including 150 patients and 35 DDI-related outcomes, were analyzed. The most frequent DDIs involved tacrolimus with N/R, resulting in creatinine increase.Eighty percent of reported DDI-related adverse events would have been identified by all drug-interaction checkers, while the remaining 20% by at least 2 of them.

CONCLUSIONS

Drug interaction checkers are useful but show inconsistencies. Multiple sources are needed to tailor treatment in the context of COVID-19.

Comparison of efficacy of continuous mycophenolate mofetil with sequential cyclophosphamide and tacrolimus as maintenance therapy for lupus nephritis

OBJECTIVES

To evaluate the renal response to mycophenolate mofetil (MMF) as maintenance therapy for lupus nephritis (LN) in Japanese patients, we compared the efficacy of MMF and the sequential use of monthly intravenous cyclophosphamide (IVCY) followed by tacrolimus (TAC).

METHODS

We examined 14 patients with LN who were treated with continuous MMF as induction and maintenance therapies (MMF group) and 10 patients with LN who received monthly IVCY as induction therapy followed by maintenance therapy with TAC (IVCY-TAC group). We assessed the therapeutic effects of each treatment regimen on renal manifestations and serological findings over a 36-month period after treatment initiation.

RESULTS

Mean urine protein-to-creatinine ratios in the MMF and IVCY-TAC groups significantly decreased from 2.75 to 0.11 g/gCr and from 3.26 to 0.22 g/gCr, respectively. Significant improvements in serum immunological variables (serum complement C3 or C4 levels and the anti-double-stranded DNA antibody titer) and reductions in the SLE disease activity index and daily prednisolone dosages were observed in both groups during induction therapy and were maintained during maintenance therapy. Efficacy was similar between the MMF and IVCY-TAC groups.

CONCLUSION

MMF has potential as an effective treatment for renal manifestations in Japanese patients throughout induction and maintenance therapies for LN, as an alternative to conventional IVCY-TAC therapy, and as a glucocorticoid-sparing agent.

Successful use of tacrolimus for treatment-refractory neuroblastoma-associated opsoclonus-myoclonus-ataxia syndrome: A case series

Opsoclonus-myoclonus-ataxia syndrome (OMAS) is an autoimmune central nervous system disorder, primarily manifesting as a paraneoplastic sequalae to neuroblastoma, and characterized by motor disorders and behavioral disturbances. OMAS is typified by aberrant B-cell and T-cell activation. Current treatment involves immunosuppression using corticosteroids, intravenous immunoglobulin, and rituximab. However, these approaches often lead to treatment-related toxicities and symptomatic recurrences with chronic neurocognitive impairment. We treated three children with refractory neuroblastoma-associated OMAS with tacrolimus, a T-cell-targeting calcineurin inhibitor, effectively controlling symptoms within a month and enabling the discontinuation of immunosuppression with minimal side effects. Tacrolimus shows promise as a therapeutic option for refractory OMAS.

Electrospun aligned tacrolimus-loaded polycaprolactone biomaterials for peripheral nerve repair

Background: Efficacious repair of peripheral nerve injury is an unmet clinical need. The implantation of biomaterials containing neurotrophic drugs at the injury site could promote nerve regeneration and improve outcomes for patients. Materials & methods: Random and aligned electrospun poly-ε-caprolactone scaffolds containing encapsulated tacrolimus were fabricated, and the gene expression profile of Schwann cells (SCs) cultured on the surface was elucidated. On aligned fibers, the morphology of SCs and primary rat neurons was investigated. Results: Both scaffold types exhibited sustained release of drug, and the gene expression of SCs was modulated by both nanofibrous topography and the presence of tacrolimus. Aligned fibers promoted the alignment of SCs and orientated outgrowth from neurons. Conclusion: Electrospun PCL scaffolds with tacrolimus hold promise for the repair of peripheral nerve injury.

Pharmacokinetics of Tacrolimus in Pregnant Solid-Organ Transplant Recipients: A Retrospective Study

Data on the pharmacokinetics of tacrolimus during pregnancy are limited. Therefore, the aim of this retrospective study was to characterize the whole-blood pharmacokinetics of tacrolimus throughout pregnancy. In this single-center retrospective cohort study, whole-blood tacrolimus trough concentrations corrected for the dose (concentration-to-dose [C/D] ratios) were compared before, monthly during, and after pregnancy in kidney, liver, and lung transplant recipients who became pregnant and gave birth between 2000 and 2022. Descriptive statistics and linear mixed models were used to characterize changes in tacrolimus C/D ratios before, during, and after pregnancy. The total study population included 46 pregnancies (31 pregnant women). Nineteen, 21, and 6 pregnancies were following kidney, liver, and lung transplantation, respectively. Immediate-release or extended-release formulations were used in 54.5% and 45.5% of the women, respectively. Tacrolimus C/D ratios significantly (P < .001) decreased (-48%) compared to the prepregnancy state at 7 months of pregnancy. These ratios recovered within 3 months postpartum (P = .002). C/D ratios tended to be lower during treatment with an extended-release formulation than with an immediate-release formulation (P = .071). Transplantation type did not significantly affect C/D ratios during pregnancy (P = .873). In conclusion, we found that tacrolimus whole-blood pharmacokinetics change throughout pregnancy, with the lowest C/D ratios (48% decrease) in the 7th month of pregnancy. In general, the decrease in C/D ratios seems to stabilize from month 4 onward compared to prepregnancy.

Adaptative Strategy of Immunosuppressive Drugs Dosage Adjustments When Combined With Nirmatrelvir/Ritonavir in Solid Organ Transplant Recipients With COVID-19

Nirmatrelvir/ritonavir is a promising option for preventing severe COVID-19 in solid organ transplant recipients with SARS-CoV-2 infection. However, concerns have arisen regarding potential drug interactions with calcineurin inhibitors (CNI). This two-phase multicentre retrospective study, involving 113 patients on tacrolimus and 13 on cyclosporine A, aimed to assess the feasibility and outcomes of recommendations issued by The French societies of transplantation (SFT) and pharmacology (SFPT) for CNI management in this context. The study first evaluated adherence to recommendations, CNI exposure, and clinical outcomes. Notably, 96.5% of patients on tacrolimus adhered to the recommendations, maintaining stable tacrolimus trough concentrations (C0) during nirmatrelvir/ritonavir treatment. After reintroduction, most patients experienced increased C0, with 42.9% surpassing 15 ng/mL, including three patients exceeding 40 ng/mL. Similar trends were observed in cyclosporine A patients, with no COVID-19-related hospitalizations. Moreover, data from 22 patients were used to refine the reintroduction strategy. Modelling analyses suggested reintroducing tacrolimus at 50% of the initial dose on day 8, and then at 100% from day 9 as the optimal approach. In conclusion, the current strategy effectively maintains consistent tacrolimus exposure during nirmatrelvir/ritonavir treatment, and a stepwise reintroduction of tacrolimus may be better suited to the low CYP3A recovery.

Correlations between serum kidney injury molecule-1, cystatin C and immunosuppressants: A cross-sectional study of renal transplant patients in Bahrain

Renal transplant patients receive several immunosuppressive drug regimens that are potentially nephrotoxic for treatment. Serum creatinine is the standard for monitoring kidney function; however, cystatin C (Cys C) and kidney injury molecule-1 (KIM-1) have been found to indicate kidney injury earlier than serum creatinine and provide a better reflection of kidney function. Here, we assessed Cys C and KIM-1 serum levels in renal transplant patients receiving mycophenolate mofetil, tacrolimus, sirolimus, everolimus, or cyclosporine to evaluate kidney function. We used both the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) 2021 equation, which is based on creatinine and combined creatinine with Cys C, and the CKD-EPI 2012 equation, which is based on Cys C alone, to estimate glomerular filtration rate (GFR). Then, we assessed the association between serum KIM-1 and GFR < 90 mL/(min·1.73 m 2). We observed significantly higher serum Cys C levels in patients with the elevated serum creatinine, compared with those with normal serum creatinine. The estimated GFRs based on creatinine were significantly higher than those based on the other equations, while a significant positive correlation was observed among all equations. Serum KIM-1 levels were negatively correlated with the estimated GFRs by the CKD-EPI Cys C and the combined creatinine with Cys C equations. A serum KIM-1 level above 0.71 ng/mL is likely to indicate GFR < 90 mL/(min·1.73 m 2). We observed a significant correlation between serum creatinine and Cys C in our renal transplant patients. Therefore, serum KIM-1 may be used to monitor renal function when using potentially nephrotoxic drugs in renal transplants.

Effects of Clarithromycin and Ketoconazole on FK506 Metabolism in Different CYP3A4 Genotype Recombinant Metabolic Enzyme Systems

OBJECTIVE

This study aimed to investigate the effects of clarithromycin and ketoconazole on the pharmacokinetic properties of tacrolimus in different CYP3A4 genotype recombinant metabolic enzyme systems, so as to understand the drug interactions and their mechanisms further.

METHOD

The experiment was divided into three groups: a blank control group, CYP3A4*1 group and CYP3A4*18 recombinant enzyme group. Each group was added with tacrolimus (FK506) of a series of concentrations. Then 1 umol/L clarithromycin or ketoconazole was added to the recombinant enzyme group and incubated in the NADPH system for 30 minutes to examine the effects of clarithromycin and ketoconazole on the metabolizing enzymes' activity of different genotypes. The remaining concentration of FK506 in the reaction system was determined using UPLC-MS/MS, and the enzyme kinetic parameters were calculated using the software.

RESULTS

The metabolism of CYP3A4*18 to FK506 was greater than that of CyP3А4*1B. Compared with the CYP3A4*1 group, the metabolic rate and clearance of FK506 in the CYP3A4*18 group significantly increased, with Km decreasing. Clarithromycin and ketoconazole inhibit the metabolism of FK506 by affecting the enzyme activity of CYP3A4*1B and CYP3A4*18B. After adding clarithromycin or ketoconazole, the metabolic rate of FK506 significantly decreased in CYP3A4*1 and CYP3A4*18, with Km increasing, Vmax and Clint decreasing.

CONCLUSION

Compared with CYP3A4*1, CYP3A4*18 has a greater metabolism of FK506, clarithromycin and ketoconazole can inhibit both the enzymatic activities of CYP3A4*1 and CYP3A4*18, consequently affecting the metabolism of FK506 and the inhibitory on CYP3A4*1 is stronger.

Long-Term Outcomes with Prolonged-Release Tacrolimus in Kidney Transplantation: A Retrospective Real-World Data Analysis

BACKGROUND Long-term real-world outcomes data for kidney transplant recipients (KTRs) converting from immediate-release tacrolimus (IRT) to prolonged-release tacrolimus (PRT) are limited. MATERIAL AND METHODS A retrospective, non-interventional review of adult KTRs treated with PRT for ≥1 month was conducted in Germany. Data were extracted from time of transplant (2008-2014) to 2018. Primary composite endpoints (graft loss, biopsy-confirmed acute rejection, graft dysfunction) and secondary endpoints (all-cause mortality, kidney function course, and tacrolimus dose/trough levels) were analyzed for sub-cohorts: de novo PRT, early conversion from IRT (within 6 months post-transplant), and late conversion (7 months to 3 years). RESULTS Analysis included 163 patients (101 de novo, 12 early converters, and 50 late converters). The overall Kaplan-Meier estimate of freedom from efficacy failure through 5 years was 0.537, (95% confidence interval (CI) 0.455-0.612) (de novo: 0.512 [0.407-0.608]; early converters: 0.500 [0.208-0.736]; late converters: 0.594 [0.443-0.717]). The overall survival rate was 0.925 (95% CI 0.872-0.957) (de novo: 0.900 [0.823-0.945]; early converters: 0.917 [0.539-0.988]; late converters: 0.977 [0.846-0.997]). During follow-up, there was a gradual reduction in tacrolimus dose and trough levels; kidney function remained stable in all cohorts. Multivariable analysis found re-transplantation, organ donor quality, best estimated glomerular filtration rate 8-12 weeks after transplant, and treatment center (between-center differences in age, sex, donor status/quality) were significantly associated with efficacy failure. CONCLUSIONS There was no difference in long-term survival profiles between KTRs who received PRT de novo vs those who converted from IRT, with 5-year survival remaining high in both groups.

Case report: Successful treatment of acute generalized pustular psoriasis with multiple comorbidities with oral tacrolimus

Acute generalized pustular psoriasis (GPP) is a serious illness. Despite various treatment methods, there is still lack of effective treatment plans for refractory cases with multiple comorbidities. This case report presents a 67-year-old woman with acute GPP, stage 4 chronic kidney disease (CKD), type 2 diabetes, and cardiovascular disease, in whom skin symptom disappearance and kidney function improvement were observed after the use of oral tacrolimus as the sole therapy. This is the first report on the application of tacrolimus in the treatment of acute GPP, especially refractory acute GPP. The successful treatment indicates that there are shared immune pathways between acute GPP and CKD, and the pathways can be interdicted by tacrolimus. Further studies are needed to optimize the therapy to maximize efficacy and minimize toxicity.

Use of LCP-Tacrolimus (LCPT) in Kidney Transplantation: A Delphi Consensus Survey of Expert Clinicians

BACKGROUND LCPT (Envarsus XR®) is a common once-daily, extended-release oral tacrolimus formulation used in kidney transplantation. However, there are minimal evidence-based recommendations regarding optimal dosing and treatment in the de novo and conversion settings. MATERIAL AND METHODS Using Delphi methodology, 12 kidney transplantation experts with LCPT experience reviewed available data to determine potential consensus topics. Key statements regarding LCPT use were generated and disseminated to the panel in an online Delphi survey. Statements were either accepted, revised, or rejected based on the level of consensus, perceived strength of evidence, and alignment with clinical practice. Consensus was defined a priori as ≥75% agreement. RESULTS Twenty-three statements were generated: 14 focused on de novo LCPT use and 9 on general administration or LCPT conversion use. After 2 rounds, consensus was achieved for 11/14 of the former and 7/9 of the latter statements. In a de novo setting, LCPT was recognized as a first-line option based on its safety and efficacy compared to immediate-release tacrolimus. In particular, African Americans and rapid metabolizer populations were identified as preferred for first-line LCPT therapy. In a conversion setting, full consensus was achieved for converting to LCPT to address neurological adverse effects related to immediate-release tacrolimus and for the time required (approximately 7 days) for steady-state LCPT trough levels to be reached. CONCLUSIONS When randomized clinical trials do not replicate current utilization patterns, the Delphi process can successfully generate consensus statements by expert clinicians to inform clinical decision-making for the use of LCPT in kidney transplant recipients.

Protective effect of FKBP12 on dextran sulfate sodium-induced ulcerative colitis in mice as a tacrolimus receptor

Ulcerative colitis (UC) is a multifactorial intestinal disease with a high incidence. In recent years, there has been an urgent need for pleiotropic drugs with a clear biosafety profile. Tacrolimus (TAC) is an immunosuppressant with stronger in vivo effects and better gastrointestinal absorption and is considered a potential treatment for UC. FKBP12 is a mediator of TAC immunosuppression; however, it is unclear whether it can participate in the development of UC in combination with TAC. The purpose of this study is to preliminarily validate the function of FKBP12 by establishing dextran sulfate sodium (DSS)-induced UC model and TAC treatment. The results revealed that TAC was effective in alleviating DSS-induced UC symptoms such as body weight and disease activity index (DAI). TAC significantly protects colonic tissue and attenuates DSS-induced histomorphological changes. In addition, FKBP12 is down-regulated in the intestinal tissue of DSS-induced UC mice and in serum samples of UC patients. In conclusion, our study revealed that FKBP12 may act as a TAC receptor to have anti-inflammatory and protective effects on DSS-induced UC in mice, which will provide a new option for the treatment of UC.

Clinical effects of tacrolimus blood concentrations early after allogeneic hematopoietic stem cell transplantation

BACKGROUND AIMS

Tacrolimus (TAC) plus short-term methotrexate (stMTX) is used for graft-versus-host disease (GVHD) prophylaxis after allogeneic hematopoietic stem cell transplantation (allo-HSCT). TAC blood concentrations are frequently adjusted to enhance the graft-versus-leukemia/lymphoma effect or attenuate severe GVHD. Limited information is available on the clinical impact of these adjustments and the optimal time to perform them in order to achieve good clinical outcomes.

METHODS

We retrospectively analyzed 211 patients who underwent allo-HSCT at our institutes.

RESULTS

Higher TAC concentrations in week 3 correlated with a significantly higher cumulative incidence of relapse (CIR) (P = 0.03) and lower nonrelapse mortality (P = 0.04). The clinical impact of high TAC concentrations in week 3 on CIR was detected in the refined disease risk index: low/intermediate (P = 0.04) and high (P < 0.01), and conditioning regimens other than cyclophosphamide/total body irradiation and busulfan/cyclophosphamide (P = 0.07). Higher TAC concentrations in week 1 correlated with a lower grade 2-4 acute GVHD rate (P = 0.01). Higher TAC concentrations in weeks 2 and 3 correlated with slightly lower (P = 0.05) and significantly lower (P = 0.02) grade 3-4 acute GVHD rates, respectively. Higher TAC concentrations in weeks 1 and 3 were beneficial for severe acute GVHD in patients with a human leukocyte antigen-matched donor (P = 0.03 and P < 0.01, respectively), not treated with anti-thymocyte globulin (P = 0.02 and P = 0.02, respectively), and receiving three stMTX doses (P = 0.03 and P = 0.02, respectively).

CONCLUSIONS

The clinical impact of TAC concentrations varied according to patient characteristics, including disease malignancy, conditioning regimens, donor sources, and GVHD prophylaxis. These results suggest that TAC management needs to be based on patient profiles.

Evaluation of the effectiveness of using prednisolone, tacrolimus, and intravenous immunoglobulin combination therapy on immune-mediated necrotizing myopathy-A non-randomized, observational research

OBJECTIVE

To recruit immune-mediated necrotizing myopathy (IMNM) patients with extramuscular manifestations who were refractory to initial therapy with either monotherapy with prednisolone or dual therapy with prednisolone and immunosuppressants. These patients subsequently received a combination of prednisolone, tacrolimus, and intravenous immunoglobulin (IVIG), and the efficacy of this treatment regimen was assessed in patients with IMNM.

METHOD

①Clinical data and treatment measures are as follows: This study enrolled IMNM patients who were treated at the Neurology Department of the First Medical Center of PLA General Hospital from April 2020 to May 2023. These patients received a combination therapy of prednisolone, tacrolimus, and IVIG. ②Observational indicators included manual muscle test for 8 groups of muscles (MMT-8), muscle enzyme levels (creatine kinase (CK), lactate dehydrogenase (LDH), alanine aminotransferase (ALT), aspartate aminotransferase (AST)), and myositis disease activity assessment tool (MDAAT).

RESULTS

This study enrolled eight patients. All observational indicators declined after treatment compared to before treatment, and these changes were statistically significant. Moreover, extramuscular manifestations also ameliorated compared to before treatment.

CONCLUSION

The combination therapy of prednisolone, tacrolimus, and IVIG has demonstrated favorable efficacy in IMNM and broadened the treatment options for this disease. However, the results still require further validation by large-scale and randomized controlled studies.

A Comprehensive Mixed-Method Approach to Characterize the Source of Diurnal Tacrolimus Exposure Variability in Children: Systematic Review, Meta-analysis, and Application to an Existing Data Set

Tacrolimus is widely reported to display diurnal variation in pharmacokinetic parameters with twice-daily dosing. However, the contribution of chronopharmacokinetics versus food intake is unclear, with even less evidence in the pediatric population. The objectives of this study were to summarize the existing literature by meta-analysis and evaluate the impact of food composition on 24-hour pharmacokinetics in pediatric kidney transplant recipients. For the meta-analysis, 10 studies involving 253 individuals were included. The pooled effect sizes demonstrated significant differences in area under the concentration-time curve from time 0 to 12 hours (standardized mean difference [SMD], 0.27; 95% confidence interval [CI], 0.03-0.52) and maximum concentration (SMD, 0.75; 95% CI, 0.35-1.15) between morning and evening dose administration. However, there was significant between-study heterogeneity that was explained by food exposure. The effect size for minimum concentration was not significantly different overall (SMD, -0.09; 95% CI, -0.27 to 0.09) or across the food exposure subgroups. A 2-compartment model with a lag time, linear clearance, and first-order absorption best characterized the tacrolimus pharmacokinetics in pediatric participants. As expected, adding the time of administration and food composition covariates reduced the unexplained within-subject variability for the first-order absorption rate constant, but only caloric composition significantly reduced variability for lag time. The available data suggest food intake is the major driver of diurnal variation in tacrolimus exposure, but the associated changes are not reflected by trough concentrations alone.

Early outcomes associated with de novo once-daily extended-release versus twice-daily immediate-release tacrolimus in a predominantly African American kidney transplant population: A single-center observational study

INTRODUCTION

The purpose of this study was to compare early outcomes of de novo LCPT (once-daily extended-release tacrolimus) to IR TAC (twice-daily immediate-release tacrolimus) in a predominantly African American (AA) adult kidney transplant population.

METHODS

This is a single center, retrospective cohort study. Patients were divided into two cohorts: IR TAC (administered between January 1, 2017, and January 31, 2019) and LCPT (administered between February 1, 2019, and May 31, 2020). Primary endpoints were changes in tacrolimus trough levels (ng/mL) and estimated glomerular filtration rate up to 12 months post-transplantation. Clinical endpoints included graft survival, delayed graft function, biopsy-proven rejection, CMV viremia, and BK. A propensity score weighted generalized linear mixed effects model was used for analysis.

RESULTS

The rate of change in tacrolimus levels was significantly higher in the LCPT cohort compared to the IR TAC cohort at 14 days post-discharge (.2455 ng/mL per day vs. .1073 ng/mL, respectively; p < .001). Subsequently, the LCPT cohort had a slightly higher rate of decline (-.015 ng/mL per day vs. -.010 ng/mL with IR TAC; p = .0894) up to 12 months post-discharge. Although eGFR was similar between the two cohorts at 12 months post-transplant, the rate of increase was slower in the LCPT cohort (.1371 mL/min per day vs. .1852 mL/min per day, p = .0314). No significant differences were found in graft survival, DGF, BPAR, CMV, or BK infection.

CONCLUSION

This study demonstrates that despite higher early trough levels with immediate post-transplant LCPT use, clinical outcomes are comparable to IR TAC at one-year post-transplant. Notably, LCPT use does not increase the incidence of DGF and that this formulation of CNI can be used as first line therapy post-transplant.

Development of a predictive model for nephrotoxicity during tacrolimus treatment using machine learning methods

AIM

When administering tacrolimus, therapeutic drug monitoring is recommended because nephrotoxicity, an adverse event, occurs at supra-therapeutic whole-blood concentrations of tacrolimus. However, some patients exhibit nephrotoxicity even at the recommended concentrations, therefore establishing a therapeutic range of tacrolimus concentration for the individual patient is necessary to avoid nephrotoxicity. This study aimed to develop a model for individualized prediction of nephrotoxicity in patients administered tacrolimus.

METHODS

We collected data, such as laboratory test data at tacrolimus initiation, concomitant drugs and tacrolimus whole-blood concentration, from medical records of patients who received oral tacrolimus. Nephrotoxicity was defined as an increase in serum creatinine levels within 60 days of tacrolimus initiation. We built 13 prediction models based on different machine learning algorithms: logistic regression, support vector machine, gradient-boosting trees, random forest and neural networks. The best performing model was compared with the conventional model, which classifies patients according to the tacrolimus concentration alone.

RESULTS

Data from 163 and 41 patients were used to construct models and evaluate the best performing one, respectively. Most of the patients were diagnosed with inflammatory or autoimmune diseases. The best performing model was built using a support vector machine; it showed a high F2 score of 0.750 and outperformed the conventional model (0.500).

CONCLUSIONS

A machine learning model to predict nephrotoxicity in patients during tacrolimus treatment was developed using tacrolimus whole-blood concentration and other patient data. This model could potentially assist in identifying high-risk patients who require individualized target therapeutic concentrations of tacrolimus prior to treatment initiation to prevent nephrotoxicity.

Variables Associated With Hyperkalemic Renal Tubular Acidosis in Solid Organ Transplant Recipients

INTRODUCTION

The occurrence of hyperkalemic renal tubular acidosis (RTA) in the post-transplantation period is likely underestimated, and its identification remains important to offer adequate medical management. Transplant recipients frequently present with clinical and biological characteristics that may be associated with the occurrence of this complication.

METHODS

This was a single-center retrospective study that compared transplanted patients with hyperkalemic RTA and a control group to identify variables associated with the occurrence of this complication. Fisher's exact test and the Mann-Whitney test, followed by multivariate logistic regression, were applied to test whether there was a significant association between hyperkalemic RTA and different variables.

RESULTS

Kidney and heart transplant recipients were at greater risk of developing RTA than lung transplant recipients (p = 0.016). There was also a significant association between the development of RTA and kalemia (p < 0.01), chloremia (p < 0.01), and bicarbonatemia (p < 0.01). The significant impact of these last three variables was confirmed by the results of the multivariate logistic regression. Residual serum tacrolimus levels (p = 0.13) and creatinine levels (p = 0.17) of renal transplant patients were not significantly associated with hyperkalemic RTA.

CONCLUSION

The type of transplanted organ, kalemia, chloremia, and bicarbonatemia were significantly associated with the occurrence of hyperkalemic RTA. This study calls into question certain approaches to managing this complication proposed in a number of case reports, such as reducing the target serum residual of tacrolimus or discontinuing trimethoprim-sulfamethoxazole (TMP-SMX) in favor of another antibiotic prophylactic agent, potentially exposing patients to graft rejection and opportunistic infections.

John's Wort

Tacrolimus is metabolized by cytochrome P450 3A (CYP3A) and is susceptible to interactions with the CYP3A and P-glycoprotein inducer St. John's Wort (SJW). CYP3A isozymes are predominantly expressed in the small intestine and liver. Prolonged-release tacrolimus (PR-Tac) is largely absorbed in distal intestinal segments and is less susceptible to CYP3A inhibition. The effect of induction by SJW is unknown. In this randomized, crossover trial, 18 healthy volunteers received single oral tacrolimus doses (immediate-release [IR]-Tac or PR-Tac, 5 mg each) alone and during induction by SJW. Concentrations were quantified using ultra-high performance liquid chromatography coupled with tandem mass spectrometry and non-compartmental pharmacokinetics were evaluated. SJW decreased IR-Tac exposure (area under the concentration-time curve) to 73% (95% confidence interval 60%-88%) and maximum concentration (Cmax ) to 61% (52%-73%), and PR-Tac exposure to 67% (55%-81%) and Cmax to 69% (58%-82%), with no statistical difference between the 2 formulations. The extent of interaction appeared to be less pronounced in volunteers with higher baseline CYP3A4 activity and in CYP3A5 expressors. In contrast to CYP3A inhibition, CYP3A induction by SJW showed a similar extent of interaction with both tacrolimus formulations. A higher metabolic baseline capacity appeared to attenuate the extent of induction by SJW.

Pharmacogenomic implications of the differential distribution of CYP3A5 metabolic phenotypes among Latin American populations

This study shows that the distribution of CYP3A5 alleles (*1, *3, *6 and *7) and genotype-predicted CYP3A5 phenotypes vary significantly across Latin American cohorts (Brazilians and the One Thousand Genomes Admixed American superpopulation), as well as among subcohorts comprising individuals with the highest proportions of Native, European or sub-Saharan African ancestry. Differences in biogeographical ancestry across the study groups are the likely explanation for these results. The differential distribution of CYP3A5 phenotypes has major pharmacogenomic implications, affecting the proportion of individuals carrying high risk CYP3A5 phenotypes for the immunosuppressant tacrolimus and the number of patients that would need to be genotyped to prevent acute rejection in kidney transplant recipients under tacrolimus treatment.

Membranous nephropathy treatment standard

Membranous nephropathy (MN) is characterized by deposition of immune complexes leading to thickening of glomerular basement membranes. Over time, the understanding of MN has evolved, with the identification of specific autoantibodies against novel podocyte antigens and the unraveling of intricate pathogenic pathways. Although the anti-CD20 monoclonal antibody rituximab is favored as part of the initial therapy in MN, a subgroup of MN patients may be resistant to rituximab necessitating the use of alternative agents such as cytotoxic therapies. In addition, newer agents such as novel anti-CD20 monoclonal antibodies, therapies targeting the CD38-positive plasma cells and anti-complement therapy are being studied in patients who are resistant to traditional treatment strategies. This manuscript furnishes a review of the novel developments in the pathophysiology of MN including the identification of target antigens and current treatment standards for MN, concentrating on evidenced-based interventions designed to attain remission and to prevent disease progression.

Reduced Prevalence of Parkinson's Disease in Patients Prescribed Calcineurin Inhibitors

Background

Preclinical evidence suggests calcineurin inhibitors (CNIs) combat α-synuclein-induced neuronal dysfunction and motor impairments. However, whether CNIs prevent or treat Parkinson's disease (PD) in humans has never been investigated.

Objective

We seek to ascertain if prescription of CNIs is linked to a decreased prevalence of PD in a varied patient population and to glimpse into the mechanism(s) and target site through which CNIs might decrease PD prevalence.

Methods

We analyzed electronic health records (EHRs) from patients prescribed the brain penetrant CNI tacrolimus (TAC), the peripherally restricted CNI cyclosporine (CySp), or the non-CNI sirolimus (SIR). For comparison, EHRs from a diverse population from the same network served as a general population-like control. After propensity-score matching, prevalence, odds, and hazards of PD diagnoses among these cohorts were compared.

Results

Patients prescribed CNIs have decreased odds of PD diagnosis compared to the general population-like control, while patients prescribed SIR do not. Notably, patients prescribed TAC have a decreased prevalence of PD compared to patients prescribed SIR or CySp.

Conclusions

Our results suggest CNIs, especially those acting within the brain, may prevent PD. The reduced prevalence of PD in patients prescribed TAC, compared to patients prescribed SIR, suggests that mechanisms of calcineurin inhibition- other than immunosuppression, which is common to both drugs- are driving the reduction. Therefore, CNIs may provide a promising therapeutic approach for PD.

Assessing the Impact of Posaconazole Cessation on Tacrolimus Serum Concentrations and Incident Cardiac Allograft Rejection: Take Caution

Invasive aspergillosis (IA) is a rare and often fatal complication of immunosuppression following orthotopic heart transplant. Prophylaxis plays a crucial role in preventing the emergence of this opportunistic infection. The azole class of medications are the bellwether agents utilized in this patient population. Unfortunately, given their impact on the Cytochrome P450 enzyme system, significant fluctuations in serum tacrolimus concentrations occur when initiating and stopping azole therapy, increasing the risk for prolonged periods of sub-optimal immunosuppression. While there are recommended dosing adjustments for these transition periods based on small data sets primarily with fluconazole, there is no published literature on recommended dosing adjustments for posaconazole. Given our institution utilizes posaconazole as the primary therapeutic for aspergillosis prophylaxis, we aimed to explore and report our local data to better guide dosing decisions during these transition periods.

Antiviral activity of immunosuppressors alone and in combinations against human adenovirus and cytomegalovirus

Human adenovirus (HAdV) and cytomegalovirus (HCMV) are cause of high morbidity and mortality in patients receiving solid organ (SOT) and hematopoietic stem cell transplantations (HSCT). Immunosuppressors are universally used to prevent graft-versus-host disease (GVHD) in HSCT and graft rejection in SOT. The long-term use of these drugs is associated with a high risk of infections, but there are also evidences of their specific interference with virus infection. The antiviral activity of immunosuppressors commonly used in the clinical practice in SOT and HSCT recipients has been evaluated in vitro to determine whether their use could be associated with less risk of HAdV and HCMV infection. Cyclophosphamide, tacrolimus, cyclosporine, mycophenolic acid, methotrexate, everolimus and sirolimus presented antiviral activity with IC50 values at low micromolar and sub-micromolar concentrations. Mycophenolic acid and methotrexate showed the greatest antiviral effects against HAdV (IC50=0.05 µM and 0.3 µM) and HCMV (IC50=10.8 µM and 0.02 µM). The combination of tacrolimus and mycophenolic acid showed strong synergic antiviral activity against both viruses with combinatory indexes (CI50) of 0.02 and 0.25, respectively. Additionally, mycophenolic acid plus cyclosporine and mycophenolic acid plus everolimus/sirolimus were synergistic against HAdV infection (CI50=0.05 and 0.09, respectively), while methotrexate plus cyclosporine were synergistic against HCMV infection (CI50=0.29). Our results, showing antiviral activities in vitro, against both HAdV and HCMV, at concentrations below the Cmax in humans of these drugs, may be relevant for the selection of specific immunosuppressant therapies in patients at risk of HAdV and HCMV infections.

A multi-center interventional study to assess pharmacokinetics, effectiveness, and tolerability of prolonged-release tacrolimus after pediatric kidney transplantation: study protocol for a prospective, open-label, randomized, two-phase, two-sequence, single dose, crossover, phase III b trial

Background

Tacrolimus, a calcineurin inhibitor (CNI), is currently the first-line immunosuppressive agent in kidney transplantation. The therapeutic index of tacrolimus is narrow due to due to the substantial impact of minor variations in drug concentration or exposure on clinical outcomes (i.e., nephrotoxicity), and it has a highly variable intra- and inter-individual bioavailability. Non-adherence to immunosuppressants is associated with rejection after kidney transplantation, which is the main cause of long-term graft loss. Once-daily formulations have been shown to significantly improve adherence compared to twice-daily dosing. Envarsus®, the once-daily prolonged-release formulation of tacrolimus, offers the same therapeutic efficacy as the conventional twice-daily immediate-release tacrolimus formulation (Prograf®) with improved bioavailability, a more consistent pharmacokinetic profile, and a reduced peak to trough, which may reduce CNI-related toxicity. Envarsus® has been approved as an immunosuppressive therapy in adults following kidney or liver transplantation but has not yet been approved in children. The objective of this study is to evaluate the pharmacokinetic profile, efficacy, and tolerability of Envarsus® in children and adolescents aged ≥ 8 and ≤ 18 years to assess its potential role as an additional option for immunosuppressive therapy in children after kidney transplantation.

Methods/design

The study is designed as a randomized, prospective crossover trial. Each patient undergoes two treatment sequences: sequence 1 includes 4 weeks of Envarsus® and sequence 2 includes 4 weeks of Prograf®. Patients are randomized to either group A (sequence 1, followed by sequence 2) or group B (sequence 2, followed by sequence 1). The primary objective is to assess equivalency between total exposure (of tacrolimus area under the curve concentration (AUC0-24)), immediate-release tacrolimus (Prograf®) therapy, and prolonged-release tacrolimus (Envarsus®) using a daily dose conversion factor of 0.7 for prolonged- versus immediate-release tacrolimus. Secondary objectives are the assessment of pharmacodynamics, pharmacogenetics, adherence, gut microbiome analyses, adverse events (including tacrolimus toxicity and biopsy-proven rejections), biopsy-proven rejections, difference in estimated glomerular filtration rate (eGFR), and occurrence of donor-specific antibodies (DSAs).

Discussion

This study will test the hypothesis that once-daily prolonged-release tacrolimus (Envarsus®) is bioequivalent to twice-daily intermediate-release tacrolimus after pediatric kidney transplantation and may reduce toxicity and facilitate medication adherence. This novel concept may optimize immunosuppressive therapy for more stable graft function and increased graft survival by avoiding T-cell mediated and/or antibody-mediated rejection due to improved adherence. In addition, the study will provide data on the pharmacodynamics and pharmacogenetics of prolonged-release tacrolimus in children and adolescents.

Clinical Trial Registration

EUDRA-CT 2019-003710-13 and ClinicalTrial.gov, identifier NCT06057545.

Rituximab Combined with Steroid and Tacrolimus Treats Proliferative Glomerulonephritis with Monoclonal IgG Deposits: A Case Report and Review of the Literature

INTRODUCTION

Due to the confounding heterogeneity, the therapeutic strategy for proliferative glomerulonephritis with monoclonal IgG deposits (PGNMID) remains to be defined.

CASE REPRESENTATION

We report a 38-year-old man with recurrent swelling of the eyelids and lower limbs, undergoing rituximab combined with steroid and tacrolimus treatment, who achieved an improved renal outcome. Underlying solid malignant tumours were excluded from the diagnosis.

DISCUSSION

We treated patients with rituximab along with steroids and tacrolimus. Improvements in proteinuria and renal function were observed. We also reviewed the current literature to assess the efficacy of rituximab in the treatment of PGNMID.

CONCLUSION

However, a larger pool of patients and a longer follow-up period are required to establish the role of rituximab and steroids in the treatment of PGNMID.

Comparison of the efficacy of steroid-free versus classic steroid-containing regimens in primary membranous nephropathy

Objective: To compare the efficacy of a steroid-free regimen with steroid-based treatment in managing primary membranous nephropathy (PMN) and investigate the potential benefits of steroid-free regimens in PMN therapy. Methods: This was a single-centre prospective cohort study. A total of 81 patients were divided into two groups according to their medication regimen: a rituximab (RTX)/tacrolimus (TAC) group (low-dose RTX combined with low-dose TAC group, without steroids, n = 31) and a prednisone (P)/TAC group (P combined with TAC group, n = 61). The changes in 24-h urine protein quantification, levels of blood albumin, blood creatinine, total cholesterol, triglyceride and fasting blood glucose as well as anti-phospholipase A2 receptor antibody titres were observed in both groups before treatment and after 1, 3, 6 and 12 months of treatment. Clinical remission (complete and partial remission), serological remission and recurrence were assessed in both groups after treatment, and the occurrence of adverse reactions was observed. Results: 1) Before treatment, there was no significant difference in baseline values between the two groups (p > 0.05). 2) After 12 months of treatment, the 24-h proteinuria and total cholesterol levels in the RTX/TAC group were significantly lower than those in the P/TAC group (p < 0.05). 3) After 6 months of treatment, the clinical remission rate of the RTX/TAC group was significantly higher than that of the P/TAC group (p < 0.05). After 12 months of treatment, the clinical remission rate of the RTX/TAC group was significantly higher than that of the P/TAC group (p < 0.05). (4) After 3, 6 and 12 months of treatment, serological remission rates in the RTX/TAC group were significantly higher than those in the P/TAC group (p < 0.05). During treatment, the anti-PLA2R antibody titres in the RTX/TAC group remained lower than those in the P/TAC group (p < 0.05). Conclusion: The low-dose RTX combined with low-dose TAC steroid-free regimen induces serological remission in patients with PMN earlier than the classic regimen of P combined with TAC, and there was no significant difference in adverse effects between the two groups. Besides, the long-term clinical remission effect of low-dose RTX combined with low-dose TAC is better than that of P combined with TAC.

Evaluation of Tacrolimus' Adverse Effects on Zebrafish in Larval and Adult Stages by Using Multiple Physiological and Behavioral Endpoints

Tacrolimus (FK506) is a common immunosuppressant that is used in organ transplantation. However, despite its importance in medical applications, it is prone to adverse side effects. While some studies have demonstrated its toxicities to humans and various animal models, very few studies have addressed this issue in aquatic organisms, especially zebrafish. Here, we assessed the adverse effects of acute and chronic exposure to tacrolimus in relatively low doses in zebrafish in both larval and adult stages, respectively. Based on the results, although tacrolimus did not cause any cardiotoxicity and respiratory toxicity toward zebrafish larvae, it affected their locomotor activity performance in light-dark locomotion tests. Meanwhile, tacrolimus was also found to slightly affect the behavior performance, shoaling formation, circadian rhythm locomotor activity, and color preference of adult zebrafish in a dose-dependent manner. In addition, alterations in the cognitive performance of the fish were also displayed by the treated fish, indicated by a loss of short-term memory. To help elucidate the toxicity mechanism of tacrolimus, molecular docking was conducted to calculate the strength of the binding interaction between tacrolimus to human FKBP12. The results showed a relatively normal binding affinity, indicating that this interaction might only partly contribute to the observed alterations. Nevertheless, the current research could help clinicians and researchers to further understand the toxicology of tacrolimus, especially to zebrafish, thus highlighting the importance of considering the toxicity of tacrolimus prior to its usage.

Two successful pregnancies in a membranous nephropathy patient: Case report and literature review

BACKGROUND

Pregnancy in patients with nephrotic syndrome presents enormous challenges to both the mother and fetus, and there are no treatment guidelines for these patients.

METHODS

We show a case of a woman with anti-PLA2R antibody-positive membranous nephropathy who did not have a kidney biopsy. Her clinical course during both pregnancies was closely followed and her medications were guided.

RESULTS

She gave birth to 2 healthy babies and her condition was very well controlled with the help of medication.

CONCLUSION

Patients with nephrotic syndrome can have successful pregnancies after drug treatment. In addition, similar to the non-pregnant population, percutaneous kidney biopsy is not required for the diagnosis of idiopathic membranous nephropathy (IMN) in pregnant nephrotic syndrome patients with anti-PLA2R antibody positive, but the etiology of secondary MN should be excluded.

Genotype-Guided Model for Prediction of Tacrolimus Initial Dosing After Lung Transplantation

The determination of the appropriate initial dose for tacrolimus is crucial in achieving the target concentration promptly and avoiding adverse effects and poor prognosis. However, the trial-and-error approach is still common practice. This study aimed to establish a prediction model for an initial dosing algorithm of tacrolimus in patients receiving a lung transplant. A total of 210 lung transplant recipients were enrolled, and 26 single nucleotide polymorphisms (SNP) from 18 genes that could potentially affect tacrolimus pharmacokinetics were genotyped. Associations between SNPs and tacrolimus concentration/dose ratio were analyzed. SNPs that remained significant in pharmacogenomic analysis were further combined with clinical factors to construct a prediction model for tacrolimus initial dose. The dose needed to reach steady state tacrolimus concentrations and achieve the target range was used to validate model prediction efficiency. Our final model consisted of 7 predictors-CYP3A5 rs776746, SLCO1B3 rs4149117, SLC2A2 rs1499821, NFATc4 rs1955915, alanine aminotransferase, direct bilirubin, and hematocrit-and explained 41.4% variance in the tacrolimus concentration/dose ratio. It achieved an area under the receiver operating characteristic curve of 0.804 (95% confidence interval, 0.746-0.861). The Hosmer-Lemeshow test yielded a nonsignificant P value of .790, suggesting good fit of the model. The predicted dose exhibited good correlation with the observed dose in the early postoperative period (r = 0.748, P less than .001). Our study provided a genotype-guided prediction model for tacrolimus initial dose, which may help to guide individualized dosing of tacrolimus in the lung transplant population in clinical practice.

Prevalence and clinical significance of potential drug-drug interactions among lung transplant patients

Background: Drug-drug interactions (DDIs) are a major but preventable cause of adverse drug reactions. There is insufficient information regarding DDIs in lung transplant recipients. Objective: This study aimed to determine the prevalence of potential DDIs (pDDIs) in intensive care unit (ICU) lung transplant recipients, identify the real DDIs and the most frequently implicated medications in this vulnerable population, and determine the risk factors associated with pDDIs. Methods: This retrospective cross-sectional study included lung transplant recipients from January 2018 to December 2021. Pertinent information was retrieved from medical records. All prescribed medications were screened for pDDIs using the Lexicomp® drug interaction software. According to this interaction software, pDDIs were classified as C, D, or X (C = monitor therapy, D = consider therapy modification, X = avoid combination). The Drug Interaction Probability Scale was used to determine the causation of DDIs. All statistical analysis was performed in SPSS version 26.0. Results: 114 patients were qualified for pDDI analysis, and total pDDIs were 4051. The most common type of pDDIs was category C (3323; 82.0%), followed by D (653; 16.1%) and X (75; 1.9%). Voriconazole and posaconazole were the antifungal medicine with the most genuine DDIs. Mean tacrolimus concentration/dose (Tac C/D) before or after co-therapy was considerably lower than the Tac C/D during voriconazole or posaconazole co-therapy (p < 0.001, p = 0.027). Real DDIs caused adverse drug events (ADEs) in 20 patients. Multivariable logistic regression analyses found the number of drugs per patient (OR, 1.095; 95% CI, 1.048-1.145; p < 0.001) and the Acute Physiology and Chronic Health Evaluation II (APACHE Ⅱ) score (OR, 1.097; 95% CI, 1.021-1.179; p = 0.012) as independent risk factors predicting category X pDDIs. Conclusion: This study revealed a high incidence of both potential and real DDIs in ICU lung transplant recipients. Immunosuppressive drugs administered with azole had a high risk of causing clinically significant interactions. The number of co-administered drugs and APACHE Ⅱ score were associated with an increased risk of category × drug interactions. Close monitoring of clinical and laboratory parameters is essential for ensuring successful lung transplantation and preventing adverse drug events associated with DDIs.

Pharmacogenomic Analysis of CYP3A5*3 and Tacrolimus Trough Concentrations in Vietnamese Renal Transplant Outcomes

Purpose

CYP3A5 polymorphisms have been associated with variations in the pharmacokinetics of tacrolimus (Tac) in kidney transplant patients. Our study aims to quantify how the CYP3A5 genotype influences tacrolimus trough concentrations (C0) in a Vietnamese outpatient population by selecting an appropriate population pharmacokinetic model of Tac for our patients.

Patients and Methods

The external dataset was obtained prospectively from 54 data of adult kidney transplant recipients treated at the 103 Military Hospital. All published Tac population pharmacokinetic models were systematically screened from PubMed and Scopus databases and were selected based on our patient's available characteristics. Mean absolute prediction error (MAPE), mean prediction error, and goodness-of-fit plots were used to identify the appropriate model for finding the formula that identifies the influence of CYP3A5 genotype on the pharmacokinetic data of Vietnamese patients.

Results

The model of Zhu et al had a good predictive ability with MAPE of 19.29%. The influence of CYP3A5 genotype on tacrolimus clearance was expressed by the following formulas: CL/F=27 , 2 × [ ( WT/70 ) 0 , 75 ] × [ ( HCT/0 , 35 ) -0 , 501 ] × [ ( POD/180 ) 0 , 0306 ] × CYP3A5 ( L/h ) . The simulation result showed that Tac C0 was significantly higher in patients not expressing CYP3A5 (p< 0.001).

Conclusion

The incorporation of the CYP3A5 phenotype into Zhu's structural model has significantly enhanced our ability to predict Tacrolimus trough levels in the Vietnamese population. This study's results underscore the valuable role of CYP3A5 phenotype in optimizing the forecast of Tac concentrations, offering a promising avenue to assist health-care practitioners in their clinical decision-making and ultimately advance patient care outcomes.

Effect of Tacrolimus Time in Therapeutic Range on Postoperative Recurrence in Patients Undergoing Liver Transplantation for Liver Cancer

BACKGROUND AND OBJECTIVE

Liver cancer is the second highest cause of cancer-related deaths worldwide. It is commonly treated with liver transplantation, where tacrolimus is typically used as an antirejection immunosuppressant. The purpose of this study was to evaluate the effect of tacrolimus time in therapeutic range (TTR) on liver cancer recurrence in liver transplant recipients and to compare the performance of TTRs calculated according to the target ranges recommended in published guidelines.

METHODS

A total of 84 patients who underwent liver transplantation for liver cancer were retrospectively included. Tacrolimus TTR was calculated using linear interpolation from the date of transplantation until recurrence or the last follow-up according to target ranges recommended in the Chinese guideline and international expert consensus.

RESULT

Twenty-four recipients developed liver cancer recurrence after liver transplantation. The CTTR (TTR calculated according to the Chinese guideline) for the recurrence group was significantly lower than that of the nonrecurrence group (26.39% vs. 50.27%, P < 0.001), whereas the ITTR (TTR calculated according to the international consensus) was not significantly different between the two groups (47.81% vs. 56.37%, P = 0.165). Multivariate survival analysis revealed that age, microvascular invasion, hepatocellular carcinoma, CTTR, and mean tacrolimus trough concentration were independent predictors of liver cancer recurrence after liver transplantation.

CONCLUSIONS

TTR predicts liver cancer recurrence in liver transplant recipients. The range of tacrolimus concentrations recommended in the Chinese guideline was more beneficial than that recommended in the international consensus for Chinese patients undergoing liver transplantation for liver cancer.

Treatment of hypopigmented burn hypertrophic scars with short-term topical tacrolimus does not lead to repigmentation

OBJECTIVES

Dyschromia is an understudied aspect of hypertrophic scar (HTS). The use of topical tacrolimus has successfully shown repigmentation in vitiligo patients through promotion of melanogenesis and melanocyte proliferation. It was hypothesized that HTSs treated with topical tacrolimus would have increased repigmentation compared to controls.

METHODOLOGY

Full-thickness burns in red Duroc pigs were either treated with excision and meshed split-thickness skin grafting or excision and no grafting, and these wounds formed hypopigmented HTSs (n = 8). Half of the scars had 0.1% tacrolimus ointment applied to the scar twice a day for 21 days, while controls had no treatment. Further, each scar was bisected with half incurring fractional ablative CO2 laser treatment before topical tacrolimus application to induce laser-assisted drug delivery (LADD). Pigmentation was evaluated using a noninvasive probe to measure melanin index (MI) at Days 0 (pretreatment), 7, 14, and 21. At each timepoint, punch biopsies were obtained and fixed in formalin or were incubated in dispase. The formalin-fixed biopsies were used to evaluate melanin levels by H&E staining. The biopsies incubated in dispase were used to obtain epidermal sheets. The ESs were then flash frozen and RNA was isolated from them and used in quantitative reverse transcription polymerase chain reaction for melanogenesis-related genes: Tyrosinase (TYR), TYR-related protein-1 (TYRP1), and dopachrome tautomerase (DCT). Analysis of variance test with Šídák's multiple comparisons test was used to compare groups.

RESULTS

Over time, within the grafted HTS and the NS group, there were no significant changes in MI, except for Week 3 in the -Tacro group. (+Tacro HTS= pre = 685.1 ± 42.0, w1 = 741.0 ± 54.16, w2 = 750.8 ± 59.0, w3 = 760.9 ± 49.8) (-Tacro HTS= pre = 700.4 ± 54.3, w1 = 722.3 ± 50.7, w2 = 739.6 ± 53.2, w3 = 722.7 ± 50.5). Over time, within the ungrafted HTS and the NS group, there were no significant changes in MI. (+Tacro HTS= pre = 644.9 ± 6.9, w1 = 661.6 ± 3.3, w2 = 650.3 ± 6.2, w3 = 636.3 ± 7.4) (-Tacro HTS= pre = 696.8 ± 8.0, w1 = 695.8 ± 12.3, w2 = 678.9 ± 14.0, w3 = 731.2 ± 50.3). LADD did not lead to any differential change in pigmentation compared to the non-LADD group. There was no evidence of increased melanogenesis within the tissue punch biopsies at any timepoint. There were no changes in TYR, TYRP1, or DCT gene expression after treatment.

CONCLUSION

Hypopigmented HTSs treated with 0.1% tacrolimus ointment with or without LADD did not show significantly increased repigmentation. This study was limited by a shorter treatment interval than what is known to be required in vitiligo patients for repigmentation. The use of noninvasive, topical treatments to promote repigmentation are an appealing strategy to relieve morbidity associated with dyschromic burn scars and requires further investigation.

Systemic calcineurin inhibitors tacrolimus and voclosporin: A review of off-label dermatologic uses

BACKGROUND

Systemic calcineurin inhibitors, cyclosporine, tacrolimus, and voclosporin, have been utilized in various dermatologic conditions. Although there have been numerous off-label dermatologic indications with published guidelines for cyclosporine, there is no established strong consensus for tacrolimus and voclosporin.

OBJECTIVE

To conduct a review of off-label use of systemic tacrolimus and voclosporin in various dermatoses to better inform treatment methods.

METHODS

A literature search was conducted using PubMed and Google Scholar. Relevant clinical trials, observational studies, case series, and reports regarding off-label dermatologic uses of systemic tacrolimus and voclosporin were included.

RESULTS

Tacrolimus shows promise for numerous dermatologic conditions, including psoriasis, atopic dermatitis/eczema, pyoderma gangrenosum, chronic urticaria, and Behcet's disease. Randomized controlled trial data are only available for voclosporin in psoriasis, which showed efficacy but did not meet noninferiority to cyclosporine.

LIMITATIONS

Data were limited and extracted from published papers. Studies differed in methodology, and nonstandardized outcomes limited the conclusions drawn.

CONCLUSIONS

In comparison to cyclosporine, tacrolimus can be considered for treatment-refractory disease or in patients with cardiovascular risk factors or inflammatory bowel disease. Voclosporin has only been utilized in psoriasis currently, and clinical trials in psoriasis show voclosporin's efficacy. Voclosporin can be considered for patients with lupus nephritis.

Etiology, risk factors and management of hypertension post liver transplantation

BACKGROUND

Cardiovascular events are one of the most important causes of morbidity and mortality in the long-term follow-up of liver transplant recipients. Hypertension is a significant cardiovascular risk factor that occurs frequently after pediatric liver transplantation. Chronic use of immunosuppressants - mainly calcineurin inhibitors - plays a major role in the development of post-transplant hypertension and circadian disturbances such as flattening of the nocturnal blood pressure dip. This requires special attention in children given the long timeframe during which immunosuppressive therapy is necessary. Careful and structured blood pressure monitoring and adequate treatment of hypertension are essential to optimize the quality of life and life expectancy of pediatric liver transplant patients. However, evidence-based guidelines for monitoring and management of post-transplant hypertension and its complications are lacking.

METHODS

We conducted a comprehensive review of the current knowledge and practices concerning post-transplant hypertension. The databases Pubmed, Embase, Web of Science and Google Scholar were scanned with the following keywords: pediatric liver transplantation, immunosuppression, tacrolimus, cardiovascular effects, hypertension, heart function, kidney function, circadian rhythm, mechanism, monitoring, and management.

RESULTS

In this review, we describe the incidence and etiology of hypertension in pediatric liver transplant recipients, the underlying mechanisms and characteristics of calcineurin inhibitor-induced hypertension, and the consequences of and risk factors for post-transplant hypertension. We hereby present an overview of the current practices in blood pressure monitoring and antihypertensive treatment as well as an algorithm for the evaluation and management of hypertension post liver transplantation. Finally, we discuss knowledge gaps and suggestions for future research.

Characterization of the calcineurin inhibitor pain syndrome in patients undergoing allogeneic hematopoietic cell transplantation

Calcineurin inhibitor pain syndrome (CIPS) is a rare complication of graft-vs-host disease prophylaxis following allogeneic hematopoietic cell transplant (alloHCT). CIPS presents as severe bilateral lower extremity pain, and the incidence, risk factors, and management of CIPS are poorly characterized.This is a single center retrospective study of patients who received tacrolimus (TAC) following alloHCT to describe the characteristics and management of CIPS and compare to a cohort who did not develop CIPS.Fifteen of 585 alloHCT patients (2.6%) developed CIPS at a median of 5 days following TAC initiation and a median level of 10.5 ng/mL. Severe bilateral foot, ankle, or leg pain were the primary symptoms. Patients with CIPS were younger and more frequently received myeloablative conditioning and total body irradiation compared to patients without CIPS. Analgesic regimens included dihydropyridine calcium channel blockers, gabapentinoids, topical diclofenac, and opioids.Clinicians should be aware of this uncommon but severe adverse effect.

A longitudinal study of long-term renal outcome after pediatric liver transplantation in relation to CNI exposure

BACKGROUND

Chronic kidney disease (CKD) is reported in 20%-30% of children after liver transplantation (LT). One of the proposed underlying causes is the long-term exposure to tacrolimus, a calcineurin inhibitor (CNI), which is the main immunosuppressive drug used after LT. Variation in tacrolimus absolute exposure and relative dose requirements are believed to be important risk factors for developing CNI-associated nephrotoxicity.

AIM

To describe the long-term renal outcome of pediatric LT recipients and determine the effects of tacrolimus exposure on renal outcome parameters.

METHODS

Retrospective single center study of renal function (GFR, proteinuria) and pharmacokinetic parameters (C0 , AUC0-12h ) obtained during annual follow-up in children after liver transplantation, between 1998 and 2019. Relevant pharmacogenetic variants for tacrolimus disposition (CYP3A5 and ABCB1) were determined in recipients and donors. The evolution of individual renal function and tacrolimus exposure was evaluated using linear mixed models for repeated measurements.

RESULTS

Twenty-six children were included (mean follow-up: 10.4 years (range 2-18.9)). Mean estimated GFR was 109.3 (SE: 7.4), vs. measured: 91.3 mL/min/1.73 m2 (SE: 6.3), which remained stable during follow-up. CKD stage ≥2 was observed in 32.8% of the visits based on eGFR versus 50.0% on mGFR. CKD stage ≥3 was uncommon (4.1% and 6.2% resp.). Mean tacrolimus C0 was 5.3 ng/mL (SE: 2.5) with a AUC0-12h of 72.7 ng*h/mL (SE: 30.3), which demonstrated a small decrease during follow-up. There was a negative correlation between C0 and mGFR (rS  = -0.3; p < .001). We found no correlation between GFR and tacrolimus dose requirements ((ng/mL)/(mg/kg)) or pharmacogenetic background.

CONCLUSION

Renal function during long-term follow-up after pediatric LT remained stable for the majority of our cohort. However, mild CKD was relatively common, warranting follow-up into adulthood. Although absolute tacrolimus exposure has a small depressing effect on concurrent GFR, there is no progressive deterioration of GFR due to long-term exposure, dose requirements or genetic background under the current target levels. These findings should be confirmed in a larger sample set, ideally including data from multiple centers.

Tacrolimus Concentration/Dose Ratio: A Tool for Guiding Tacrolimus Dosage Post-renal Transplantation

Background The calcineurin inhibitor, Tacrolimus (Tac), exhibits variable absorption and undergoes first-pass metabolism when administered orally. The narrow therapeutic window and individual variability of this immunosuppressive agent make therapeutic drug monitoring essential. We hypothesized that the Tac metabolism rate - defined as the blood concentration normalized by its daily dose (the C/D ratio) - is associated with post-renal transplant (RTx) function. Methodology A retrospective observational study was conducted including 40 RTx patients. Clinical reports from four follow-up ambulatory appointments at one, three, six, and 12 months were analyzed. Tac dose and its blood levels were used to calculate the Tac concentration/dose (C/D) ratio. Patients with a Tac C/D ratio <1.05 ng/mL x 1/mg and a C/D ratio >1.05 ng/mL x 1/mg were categorized as fast and slow metabolizers. Serum creatinine levels were compared between the two groups, and their association with the Tac C/D ratio was analyzed. Student's unpaired t-test and the Mann-Whitney U test were used to analyze the difference in the C/D ratio between the groups. Spearman correlation analysis was conducted to analyze the association of the C/D ratio with serum creatinine in both groups. A P-value of <0.05 was considered statistically significant. Results Fast metabolizers showed increased serum creatinine (P < 0.05), and the C/D ratio correlated with creatinine levels. ROC analysis used to identify fast metabolizers for the C/D ratio at three months had an area of 0.925 (P < 0.01). Conclusions The Tac C/D ratio can be used as an earlier diagnostic tool to predict the development of nephrotoxicity in RTx patients.

Anti-inflammatory and antioxidative actions of tacrolimus (FK506) on human microglial HMC3 cell line

Microglial cells are indispensable for the normal development and functioning of neurons in the central nervous system, where they play a crucial role in maintaining brain homeostasis by surveilling the microenvironment for signs of injury or stress and responding accordingly. However, in neurodegenerative diseases, the density and phenotypes of microglial cells undergo changes, leading to chronic activation and inflammation. Shifting the focus from neurons to microglia in drug discovery for neurodegenerative diseases has become an important therapeutic target. This study was aimed to investigate the potential of Tacrolimus (FK506) an FDA-approved calcineurin inhibitor, to modulate the pathology of neurodegenerative diseases through anti-inflammatory and antioxidative effects on microglial activation. The human microglia clone 3 (HMC3) cells were exposed to 1 μg/mL LPS in the presence and absence of doses of FK506. Survival rates of cells were determined using the 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide (MTT) method. Morphological evaluation of cells showed that FK506 restored the normal morphology of activated microglia. Furthermore, FK506 treatment increases the total antioxidant capacity and reduces the total oxidative capacity, indicating its potential antioxidant effects. Data from ELISA and RT-PCR analyses showed that LPS abolished its promoting effects on the release of proinflammatory IL-1β and IL-6 cytokines in HMC3 cells, reflecting the anti-inflammatory effect of FK506. These findings support the idea that FK506 could be a promising therapeutic agent for neurodegenerative diseases by modulating microglial activation and reducing inflammation and oxidative stress.

Sigmoid Colon Perforation in Diffuse Large B-Cell Lymphoma Due to Tacrolimus-Induced Immunodeficiency: A Case Report

The sigmoid colon is an uncommon site for the origin of primary malignant lymphomas in the GI tract. Additionally, immunosuppressive agents, widely used in treating autoimmune diseases, have been associated with the induction of malignancies, including lymphoproliferative disorders. In this report, we present a rare case of GI perforation suggesting a link between immunosuppressive therapy, particularly tacrolimus treatment, and diffuse large B-cell lymphoma (DLBCL). A 75-year-old female patient presented with abdominal pain to our ER. She had a medical history of polymyositis and interstitial pneumonia, treated with the immunosuppressant tacrolimus. An abdominal CT scan revealed free gas in the abdominal cavity, leading to a diagnosis of GI perforation. The patient exhibited generalized peritonitis and underwent emergency surgery the same day. During surgery, a perforation in the sigmoid colon was identified, and a Hartmann procedure was performed. Postoperative pathology showed CD20+, CD30+, CD5-, CD10-, BCL6+, MUM1+, and MIB-1 LI of 50-60%. The diagnosis of DLBCL was confirmed, classified as EBV-positive diffuse large B-cell lymphoma, not otherwise specified (NOS), in the sigmoid colon, with positive EBER-ISH, LMP-1, and EBNA2 findings. Given her history of immunosuppressant use, she was categorized as having other iatrogenic immunodeficiency-associated lymphoproliferative disorders (OIIA-LPD), according to the WHO Classification of 2017. This case highlights the importance for clinicians to consider the risk of oncogenesis associated with the prolonged use of immunosuppressive agents.

Effects of Wuzhi Capsule on Whole-Blood Tacrolimus Concentration Levels: A Systematic Review and Meta-Analysis

BACKGROUND

Wuzhi Capsule (WZC) is a traditional Chinese medicinal herb widely used to treat drug-induced hepatitis or liver dysfunction and is usually prescribed in China to increase tacrolimus concentration. Several studies with small sample sizes have shown that WZC can increase tacrolimus concentration levels in clinical practice. This study aimed to evaluate the effect of WZC on whole-blood tacrolimus concentration levels and safety.

METHODS

We searched 7 databases for randomized clinical trials (RCTs) and observational studies (OSs) comparing whole-blood tacrolimus concentration levels between WZC and non-WZC treatments. Data analysis was performed using Review Manager version 5.3. This study was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses reporting guidelines.

RESULTS

Eleven studies involving 6 RCTs and 5 OSs were included. The meta-analysis indicated that whole-blood tacrolimus concentration levels in the WZC group was significantly higher than that of the non-WZC group [weighted mean difference = 1.38, 95% CI (confidence interval), 1.21-1.56, P < 0.001], and similar results were shown in all the subgroups of follow-up time, different primary disease, and different WZC doses. In the self-control OSs, the whole-blood tacrolimus concentration levels in the WZC group was significantly higher than the non-WZC group (weighted mean difference = 1.17, 95% CI, 0.71-1.64, P < 0.001). WZC was generally well tolerated and there was no significant difference in the incidence of adverse reactions between the 2 groups.

CONCLUSIONS

WZC can increase whole-blood tacrolimus concentration levels. This may be an economical and practical treatment choice for patients, especially those with poor oral tacrolimus absorption capabilities. Nevertheless, RCTs and OSs with large sample sizes and high quality are needed in the future to confirm these positive results.

Population pharmacokinetic models of tacrolimus in paediatric solid organ transplant recipients: A systematic review

AIMS

This study aimed to provide up-to-date information on paediatric population pharmacokinetic models of tacrolimus and to identify factors influencing tacrolimus pharmacokinetic variability.

METHODS

Systematic searches in the Web of Science, PubMed, Scopus, Science Direct, Cochrane, EMBASE databases and reference lists of articles were conducted from inception to March 2023. All population pharmacokinetic studies of tacrolimus using nonlinear mixed-effect modelling in paediatric solid organ transplant patients were included.

RESULTS

Of the 21 studies reviewed, 62% developed from liver transplant recipients and 33% from kidney transplant recipients. Most studies used a 1-compartment model to describe tacrolimus pharmacokinetics. Body weight was a significant predictor for tacrolimus volume of distribution (Vd/F). The estimated Vd/F for 1-compartment models ranged from 20 to 1890 L, whereas the peripheral volume of distribution (Vp/F) for 2-compartment models was between 290 and 1520 L. Body weight, days post-transplant, CYP3A5 genotype or haematocrit were frequently reported as significant predictors of tacrolimus clearance. The estimated apparent clearance values range between 0.12 and 2.18 L/h/kg, with inter-individual variability from 13.5 to 110.0%. Only 29% of the studies assessed the generalizability of the models with external validation.

CONCLUSION

This review highlights the potential factors, modelling approaches and validation methods that impact tacrolimus pharmacokinetics in a paediatric population. The clinician could predict tacrolimus clearance based on body weight, CYP3A5 genotype, days post-transplant or haematocrit. Further research is required to determine the relationship between pharmacogenetics and tacrolimus pharmacodynamics in paediatric patients and confirm the applicability of nonlinear kinetics in this population.

cyclosporine in pediatric hematopoietic stem cell transplantation for thalassemia

OBJECTIVES

Graft-versus-host disease (GvHD) is one of the leading causes of morbidity and mortality in patients undergoing allogeneic HSCT, and effective prevention of GvHD is critical for the success of the HSCT procedure. Calcineurin inhibitors (CNI) have been used for decades as the backbone of GvHD prophylaxis. In this study, the efficacy and safety of Cyclosporine A (CsA) and tacrolimus (TCR) were compared in pediatric HSCT for thalassemia.

MATERIALS AND METHODS

This is a retrospective analysis of 129 pediatric patients who underwent HSCT with the diagnosis of thalassemia at Medicalpark Göztepe and Antalya Hospitals between January 2017 and December 2020.

RESULTS

Despite the GvHD prophylaxis, grade II-IV acute GvHD developed in 29 patients. Of these patients, 12 had only gut, 10 had only skin, 6 had combined gut and skin, and one had only liver GvHD. Fifteen of these 29 patients were in the CsA group, and 14 of them were in the TCR group. There was no significant difference between the groups in terms of acute GvHD occurrence, GvHD stage, or involvement sites. In terms of CNI-related toxicity, neurotoxicity in 15 (CsA n = 9, TCR n = 6) and nephrotoxicity in 18 (CsA n = 4, TCR n = 14) patients were observed. While there was no difference between the two groups in terms of neurotoxicity, more nephrotoxicity developed in patients using TCR (p = .013). There was no significant difference between the groups in terms of engraftment syndrome, veno-occlusive disease, CMV reactivation, PRES, or graft rejection.

CONCLUSION

Regarding GvHD, there was no difference in efficacy between TCR and CsA usage. Patients taking TCR experienced noticeably higher nephrotoxicity in terms of adverse effects. This difference should be considered according to the patient's clinical situation while choosing a CNI.

Interstitial lung changes and persistent COVID-19 in a patient with follicular lymphoma: A case report

We herein report a case of interstitial lung changes in a patient with prolonged coronavirus disease 2019 (COVID-19) with follicular lymphoma receiving rituximab and bendamustine who recovered after treatment with a combination therapy consisting of corticosteroids and immunosuppressive agents. There is currently no treatment strategy for prolonged pneumonitis following COVID-19, which can be life-threatening for immunocompromised patients. Thus, further investigation is warranted.

Predicting Tacrolimus Concentrations in the Skin of Adult Kidney Transplant Recipients: A Feasibility Study

Solid organ transplant recipients are at an increased risk of developing skin cancers due to chronic immunosuppression, particularly with calcineurin inhibitors. Tacrolimus is the most prescribed calcineurin inhibitor in this patient cohort, and understanding tacrolimus concentrations in the skin will facilitate the development of anti-cancer preventive and therapeutic strategies. Here, we show that in mice, tacrolimus blood levels peaked rapidly ∼1 h post last oral dose while skin levels rose more slowly and remained high for at least 6 h. Subsequently, tacrolimus skin and blood concentrations were assessed in 15 kidney transplant recipients. The mean age was 61 years, the average time post-transplant was 7 years (range 0-21 years) and 87% were male. The average skin sampling time post tacrolimus dosing was 6 h 32 min. Skin tacrolimus concentrations ranged from 7.1 ng/g to 71.2 ng/g and correlated with blood concentrations (r = 0.6). Mouse and human mean skin concentrations were in a similar range. Our data suggests that tacrolimus measurements in the blood may be used to approximate tacrolimus concentrations in the skin of kidney transplant recipients, and further exploited for the delivery of anti-cancer therapies designed to antagonize the immunosuppressive effects of tacrolimus in the skin.