Effect of hepatitis C infection on tacrolimus doses and blood levels in liver transplantation recipients

Tacrolimus Exposure in Obese Patients: and A Case-Control Study in Kidney Transplantation

BACKGROUND

Tacrolimus pharmacokinetics in obese (Ob) patients has been poorly studied. In this article, the authors explored the impact of obesity on tacrolimus exposure in kidney transplant recipients (KTRs) and estimated a more suitable initial dosage in this population.

METHODS

A retrospective, observational, monocentric case-control study was performed in obese KTRs (BMI > 30 kg/m2) who received tacrolimus between 2013 and 2017 (initial dose: 0.15 mg/kg/d) (actual weight). Nonobese (Nob) controls (BMI <30 kg/m2) were matched for age and sex. Weekly centralized monitoring of tacrolimus trough levels was performed by liquid chromatography/mass spectrometry until the third month (M3). Target trough levels were set between 8 and 10 ng/mL. All patients received antilymphocyte globulin, corticosteroids, and mycophenolate mofetil.

RESULTS

Of the 541 KTRs, 28 tacrolimus-treated Ob patients were included and compared with 28 NOb-matched controls. With a mean of 22 assays/patient, tacrolimus trough levels were higher in Ob patients (mean 9.9 versus 8.7 ng/mL; P = 0.008); the weight-related dose of Tac was lower at M3 (mean 0.10 versus 0.13 mg/kg/d, P < 0.0001). The tacrolimus concentration to dose (C0/D) was higher in the Ob cohort [mean 116 versus 76 (ng/mL)/(mg/kg/d); P = 0.001]. In Ob patients, a mean decrease of -4.6 mg/d in the 3 months after tacrolimus initiation was required (versus -1.12 in NOb; P = 0.001) to remain within the therapeutic range. Obesity, high mycophenolate mofetil daily dose at M3, and CYP3A5 expression were independently associated with higher tacrolimus exposure. Four dose-adaptation strategies were simulated and compared with the study results.

CONCLUSIONS

An initial dose calculation based on either ideal or lean body weight may allow for faster achievement of tacrolimus trough level targets in Ob KTRs, who are at risk of overexposure when tacrolimus is initiated at 0.15 mg/kg/d. A prospective study is required to validate alternative dose calculation strategies in these patients.

Hepatitis C Virus Eradication with New Interferon-Free Treatment Improves Metabolic Profile in Hepatitis C Virus-Related Liver Transplant Recipients

Interferon (IFN)-free, direct-acting antiviral (DAA) therapy agents provide a safe and efficacious treatment for liver transplant recipients with recurrent hepatitis C virus (HCV) infection. The aim of this study is to evaluate the impact of HCV eradication on the metabolic factors in liver transplant recipients. We completed a retrospective single-center study on HCV-related liver transplant recipients treated with IFN-free DAAs including both treatment-naive and treatment-experienced patients. IFN-free DAAs impact on the metabolic profile were assessed at baseline and sustained virological response (SVR) between 24 and 48 weeks. In total, 91 liver transplant recipients with recurrent HCV infection received IFN-free DAA treatment, 62 patients had IFN-based treatment failure, and 29 were treatment-naïve, of whom 87 (96%) achieved SVR. Eradication of recurrent HCV infection was associated with reduction in the treatment of diabetes and hypertension by 38% and 22% from the baseline respectively. Hemoglobin A1c (HbA1c) levels declined from mean 35.5 ± 4.3 mmol/mol to 33.3 ±3.6 mmol/mol at 44 weeks posttreatment (P = 0.03). Total cholesterol levels increased from 3.8 ± 0.9 mmol/L to 4.9 ± 0.9 mmol/L at 41 weeks posttreatment (P < 0.0001), reflecting a significant increase in serum low-density lipoprotein (LDL) levels (2.0 ± 0.8 to 2.9 ± 0.8; P < 0.0001). Estimated glomerular filtration rate (eGFR) levels increased from 64.9 ± 20 mL/minute to 69.6 ± 20 mL/minute at 24 weeks posttreatment (P = 0.0004). Glucose, lipid profile, and eGFR changes were independent of weight changes and immunosuppression dosage and trough levels. In conclusion, eradication of recurrent HCV infection by DAA therapy has beneficial impacts on glucose metabolism and renal profile and reverses the hypolipidemic effect of HCV in liver transplant recipients. These extrahepatic effects of DAA therapy need to be validated by larger prospective studies.

Donor and recipient P450 gene polymorphisms influence individual pharmacological effects of tacrolimus in Chinese liver transplantation patients

The immunosuppressant drug tacrolimus (Tac) used for the prevention of immunological rejection is a metabolic substrate of cytochrome P450 enzymes. This study was designed to evaluate the short-term and long-term potential influence of single-nucleotide polymorphisms (SNPs) in CYP450 genes of liver transplant (LT) recipients as well as the donors on individual pharmacological effects of Tac and to guide individualized-medication from the perspective of pharmacogenomics. Twenty-one SNPs of the CYP450 gene were genotyped for both recipients and donors in 373 LT patients receiving Tac-based immunosuppressants. The Tac concentration/dosage ratio (C/D) was evaluated from the initial medication until one year after LT. The C/D ratio was significantly higher when the donor and/or recipient genotype of CYP3A5 rs776746 was G/G or rs15524 was T/T or rs4646450 was C/C all through one year after transplantation. Comparing the effect of donor gene variants of rs776746, rs15524, and rs4646450 on Tac C/D ratios with the recipients, statistically significant differences were found between the donor T/T group and the recipient T/T group in rs15524 at 1 month and 6 months, and at 6 months, the donor C/C group differed from the recipient C/C group in rs4646450. In conclusion, rs776746, rs15524, and rs4646450 of CYP3A5 had a significant influence on Tac pharmacological effects for both the initial use and long-term use. The donor liver genotype and the recipient intestine genotype contribute almost equally in the short-term, but the donor genotype had a greater effect than the recipient genotype at 6 months. Personalized Tac treatment after LT should be based on the CYP3A5 genotype.

Which Kidney Transplant Recipients Can Benefit from the Initial Tacrolimus Dose Reduction?

Background

Observational data suggest that the fixed initial recommended tacrolimus (Tc) dosing (0.2 mg/kg/day) results in supratherapeutic drug levels in some patients during the early posttransplant period. The aim of the study was to analyze a wide panel of patient-related factors and their interactions which increase the risk for first Tc blood level > 15 ng/ml.

Materials and Methods

We performed a retrospective analysis of 488 consecutive adult kidney transplant recipients who were initially treated with triple immunosuppressive regimen containing tacrolimus twice daily. The analysis included the first assessment of Tc trough blood levels and several demographic, anthropometric, laboratory, and comedication data.

Results

The multiple logistic regression analysis showed that age > 55 years, BMI > 24.6 kg/m², blood hemoglobin concentration > 9.5 g/dl, and the presence of anti-HCV antibodies independently increased the risk for first Tc level > 15 ng/ml. The relative risk (RR) for first tacrolimus level > 15 ng/ml was 1.88 (95% CI 1.35–2.64, p < 0.001) for patients with one risk factor and 2.81 (2.02–3.89, p < 0.001) for patients with two risk factors.

Conclusions

Initial tacrolimus dose reduction should be considered in older, overweight, or obese kidney transplant recipients and in subjects with anti-HCV antibodies. Moreover, dose reduction of tacrolimus is especially important in patients with coexisting multiple risk factors.

Practical Recommendations for Long-term Management of Modifiable Risks in Kidney and Liver Transplant Recipients: A Guidance Report and Clinical Checklist by the Consensus on Managing Modifiable Risk in Transplantation (COMMIT) Group

Short-term patient and graft outcomes continue to improve after kidney and liver transplantation, with 1-year survival rates over 80%; however, improving longer-term outcomes remains a challenge. Improving the function of grafts and health of recipients would not only enhance quality and length of life, but would also reduce the need for retransplantation, and thus increase the number of organs available for transplant. The clinical transplant community needs to identify and manage those patient modifiable factors, to decrease the risk of graft failure, and improve longer-term outcomes.COMMIT was formed in 2015 and is composed of 20 leading kidney and liver transplant specialists from 9 countries across Europe. The group's remit is to provide expert guidance for the long-term management of kidney and liver transplant patients, with the aim of improving outcomes by minimizing modifiable risks associated with poor graft and patient survival posttransplant.The objective of this supplement is to provide specific, practical recommendations, through the discussion of current evidence and best practice, for the management of modifiable risks in those kidney and liver transplant patients who have survived the first postoperative year. In addition, the provision of a checklist increases the clinical utility and accessibility of these recommendations, by offering a systematic and efficient way to implement screening and monitoring of modifiable risks in the clinical setting.

Interferon-free antiviral therapy for chronic hepatitis C among patients in the liver transplant setting

Chronic hepatitis C (HCV) infection remains a major public health problem with many infected individuals worldwide. The revolutionary discovery of highly effective direct-acting antivirals (DAAs) makes chronic HCV infection a curable disease, even in patients with advanced liver disease. Liver function may improve shortly after initiation of antiviral therapy in patients on the waiting list and could even obviate the need for transplantation. However, whether these short term benefits also result in a favorable prognosis on the long-term remains to be seen and this fuels the discussion whether DAAs should be used prior to liver transplantation in all patients. Following liver transplantation, DAA treatment is also highly effective so that postponing antiviral treatment to the post-transplant setting may be better for certain patients. Furthermore, the discussion whether HCV positive organ donors should be used now viral eradication is achieved in almost all patients has regained interest.

Optimal timing for hepatitis C therapy in US patients eligible for liver transplantation: a cost-effectiveness analysis

BACKGROUND

Recurrence of hepatitis C virus (HCV) following liver transplantation (LT) is universal for those with ongoing viraemia and is associated with higher rates of allograft failure and death. However, the optimal timing of HCV treatment for patients awaiting transplant remains unclear.

AIM

To evaluate the comparative cost-effectiveness of treating HCV pre-LT vs. post-LT (pre-emptive or after HCV recurrence).

METHODS

A Markov state-transition model was created to simulate the progression of a cohort of HCV-genotype 1 or 4 cirrhotic patients from the time of transplant listing until death. We then used this model to study the cost-effectiveness of ledipasvir-sofosbuvir (LDV/SOF) with ribavirin for 12 weeks, administered for three separate treatment strategies: (i) pre-LT; (ii) post-LT preemptively prior to HCV recurrence; or (iii) post-LT after HCV recurrence.

RESULTS

In the base-case analysis using a median model for end-stage liver disease (MELD) score <25 at the time of transplant, we found that pre-LT treatment of HCV led to more QALYs for fewer dollars compared to other strategies. Analysis limited to living donor LT recipients revealed that pre-LT treatment was also the most cost-effective strategy. When the analysis was repeated for MELD ≥25, decompensated disease (Child-Pugh class B or C), and hepatocellular carcinoma cases, preemptive post-LT strategy was more cost-effective.

CONCLUSIONS

Treatment of HCV prior to liver transplantation appears to be the most cost-effective strategy for patients with a MELD score <25. For patients with a MELD ≥25 or decompensated cirrhosis, preemptive post-liver transplantation treatment before HCV recurrence is the most cost-effective strategy.

Efficacy and Safety of Direct Acting Antivirals in Kidney Transplant Recipients with Chronic Hepatitis C Virus Infection

The prevalence of Hepatitis C Virus (HCV) infection is significantly higher in patients with end-stage renal disease compared to the general population and poses important clinical challenges in patients who undergo kidney transplantation. Historically, interferon-based treatment options have been limited by low rates of efficacy and significant side effects, including risk of precipitating rejection. Limited data exist on the use of all-oral, interferon-free direct-acting antiviral (DAA) therapies in kidney transplant recipients. In this study, we performed a retrospective chart review with prospective clinical follow-up of post-kidney transplant patients treated with DAA therapies at three major hospitals in Boston, MA. A total of 24 kidney recipients with HCV infection received all-oral DAA therapy post-transplant. Patients were predominantly male (79%) with a median age of 60 years (range 34–70 years), median creatinine of 1.2 mg/dL (0.66–1.76), and 42% had advanced fibrosis or cirrhosis. The majority had HCV genotype 1a infection (58%). All patients received full-dose sofosbuvir; it was paired with simeprevir (9 patients without and 3 patients with ribavirin), ledipasvir (7 patients without and 1 patient with ribavirin) or ribavirin alone (4 patients). The overall sustained virologic response (SVR12) was 91% (21 out of 23 patients). One patient achieved SVR4 but demised prior to SVR12 check point due to treatment unrelated cause. Two treatment failures were successfully retreated with alternative DAA regimens and achieved SVR. Both initials failures occurred in patients with advanced fibrosis or cirrhosis, with genotype 1a infection, and prior HCV treatment failure. Adverse events were reported in 11 patients (46%) and were managed clinically without discontinuation of therapy. Calcineurin inhibitor trough levels did not significantly change during therapy. In this multi-center series of patients, all-oral DAA therapy appears to be safe and effective in post-kidney transplant patients with chronic HCV infection.

Ledipasvir and Sofosbuvir Plus Ribavirin for Treatment of HCV Infection in Patients With Advanced Liver Disease

BACKGROUND & AIMS

There are no effective and safe treatments for chronic hepatitis C virus (HCV) infection of patients who have advanced liver disease.

METHODS

In this phase 2, open-label study, we assessed treatment with the NS5A inhibitor ledipasvir, the nucleotide polymerase inhibitor sofosbuvir, and ribavirin in patients infected with HCV genotypes 1 or 4. Cohort A enrolled patients with cirrhosis and moderate or severe hepatic impairment who had not undergone liver transplantation. Cohort B enrolled patients who had undergone liver transplantation: those without cirrhosis; those with cirrhosis and mild, moderate, or severe hepatic impairment; and those with fibrosing cholestatic hepatitis. Patients were assigned randomly (1:1) to receive 12 or 24 weeks of a fixed-dose combination tablet containing ledipasvir and sofosbuvir, once daily, plus ribavirin. The primary end point was sustained virologic response at 12 weeks after the end of treatment (SVR12).

RESULTS

We enrolled 337 patients, 332 (99%) with HCV genotype 1 infection and 5 (1%) with HCV genotype 4 infection. In cohort A (nontransplant), SVR12 was achieved by 86%-89% of patients. In cohort B (transplant recipients), SVR12 was achieved by 96%-98% of patients without cirrhosis or with compensated cirrhosis, by 85%-88% of patients with moderate hepatic impairment, by 60%-75% of patients with severe hepatic impairment, and by all 6 patients with fibrosing cholestatic hepatitis. Response rates in the 12- and 24-week groups were similar. Thirteen patients (4%) discontinued the ledipasvir and sofosbuvir combination prematurely because of adverse events; 10 patients died, mainly from complications related to hepatic decompensation.

CONCLUSION

The combination of ledipasvir, sofosbuvir, and ribavirin for 12 weeks produced high rates of SVR12 in patients with advanced liver disease, including those with decompensated cirrhosis before and after liver transplantation. ClinTrials.gov: NCT01938430.

What is the long-term outcome of the liver allograft?

With improved long-term survival following liver transplantation (LT), issues relating to the assessment of the liver allograft in long-term survivors are becoming increasingly relevant. Histological abnormalities are commonly present in late post-transplant biopsies, including protocol biopsies from patients who appear to be well with good graft function. Recurrent disease is the commonest recognised cause of abnormal graft histology, but may be modified by the effects of immunosuppression or interactions with other graft complications, resulting in complex or atypical changes. Other abnormalities seen in late post-transplant biopsies include rejection (which often has different appearances to those seen in the post-transplant period), de novo disease, "idiopathic" post-transplant hepatitis (IPTH) and nodular regenerative hyperplasia. In many cases graft dysfunction has more than one cause and liver biopsy may help to identify the predominant cause of graft damage. Problems exist with the terminology used to describe less well understood patterns of graft injury, but there is emerging evidence to suggest that late rejection, de novo autoimmune hepatitis and IPTH may all be part of an overlapping spectrum of immune-mediated injury occurring in the late post-transplant liver allograft. Careful clinico-pathological correlation is very important and the wording of the biopsy report should take into account therapeutic implications, particularly whether changes in immunosuppression may be indicated. This article will provide an overview of the main histological changes occurring in long-term survivors post-LT, focusing on areas where the assessment of late post-transplant biopsies is most relevant clinically.

The spectrum of hepatic functional impairment in compensated chronic hepatitis C: results from the Hepatitis C Anti-viral Long-term Treatment against Cirrhosis Trial

BACKGROUND

The spectrum of functional impairment in patients with compensated chronic hepatitis C is incompletely defined.

AIM

To define hepatic impairment by quantitative tests (quantitative liver function tests) and correlate results with disease severity in patients with chronic hepatitis C.

METHODS

We studied 285 adult patients with chronic hepatitis C prior to treatment in the Hepatitis C Anti-viral Long-term Treatment against Cirrhosis Trial; 171 had Ishak fibrosis stages 2-4 (fibrosis) and 114 had stage 5 or 6 (cirrhosis). None had had clinical decompensation. A battery of 12 quantitative liver function test assessed the spectrum of hepatic microsomal, mitochondrial and cytosolic functions, and hepatic and portal blood flow.

RESULTS

Twenty-six to 63% of patients with fibrosis and 45-89% with cirrhosis had hepatic impairment by quantitative liver function test; patients with cirrhosis had the greatest impairment (P-value ranging from 0.15 to <0.0001). Cholate Cl(oral), cholate shunt and perfused hepatic mass correlated with cirrhosis, stage of fibrosis (r = -0.51, +0.49, -0.51), varices and variceal size (r = -0.39, +0.36, -0.41). PHM < 95 and cholate shunt >35% identified 91% of patients with medium- or large-sized varices.

CONCLUSIONS

Hepatic impairment is common in compensated patients with fibrosis or cirrhosis because of chronic hepatitis C. Cholate shunt, and cholate Cl(oral) and perfused hepatic mass, identify patients at risk for cirrhosis or varices.

Tacrolimus and cyclosporin doses and blood levels in hepatitis C and alcoholic liver disease patients after liver transplantation

Hepatitis C virus (HCV)-induced cirrhosis is the most common indication for liver transplantation (LT). However, graft reinfection is nearly universal. The choice of immunosuppression, including the calcineurin inhibitor (CNI), may have some effect on severity of recurrence and graft survival. In addition, HCV recurrence may have some impact on metabolism of immunosuppressive drugs. In this retrospective study, we examined the dose and blood levels of tacrolimus (TAC) and cyclosporin A (CYA) in HCV patients consecutively undergoing transplantation (TAC, n = 44; CYA, n = 60) and surviving 12 months post-LT. In addition, we examined the CNI dose and blood levels in an age- and gender-matched comparison group of patients who were transplanted for alcoholic liver disease (ALD) (TAC, n = 44; CYA, n = 47). During the 12-month period of observation, TAC levels were significantly higher for HCV than for ALD patients (P = 0.002). The dose of TAC decreased over time for both HCV and ALD patients (P < 0.001), but the reduction was greater for HCV patients (P = 0.03). CYA dose decreased over time for both groups (P < 0.001) but a greater reduction was observed for the HCV group (P = 0.007). For both HCV and ALD patients, CYA levels decreased over time (P < 0.001) but there was no significant difference between HCV and ALD patients. Thus, to maintain comparable blood levels, a greater reduction of dose was required for HCV than for ALD patients. In conclusion, our observations demonstrate a likely effect of HCV infection on CNI metabolism, an effect that is not clearly due to graft damage. Physicians need to be alert to this interaction and to the need to respond quickly to changes in CNI levels that may be associated with HCV infection and with HCV clearance during antiviral therapy.

Chronic ductopenic rejection in patients with recurrent hepatitis C virus treated with pegylated interferon alfa-2a and ribavirin

BACKGROUND

Interferon use for post liver transplantation (LT) recurrent hepatitis C (HCV) has not consistently been associated with acute cellular rejection (ACR). We examined the incidence of chronic ductopenic rejection (CR) in patients receiving pegylated interferon alfa-2a and ribavirin (PEG) to treat recurrent HCV.

METHODS

A chart review of 12 patients developing CR while receiving an escalating dose regimen of PEG with protocol liver biopsies every 6 months was conducted. Values are shown as median (range).

RESULTS

Twelve of the 70 patients treated with PEG developed CR. Median age at LT was 53 (37-63) years; immunosuppression consisted of tacrolimus or cyclosporine with prednisone. PEG was started at 3.6 (0.2-13.5) years after LT. Two patients had one episode of ACR before PEG. Four patients had first ACR while receiving PEG. CR was diagnosed after 12 (4-17) months of PEG; by then 8 patients had undetectable HCV-RNA. Tacrolimus and cyclosporine levels (ng/mL) were 7.9 (3.2-18.9) and 76 (71-93) before PEG, and 6.9 (3.7-9.7) and 130 (81-153) at CR. Six patients were treated more than 1 year with PEG; three had undetectable HCV-RNA when CR was diagnosed. Five patients are being treated for CR; one has been listed for LT; two patients were retransplanted. Five patients died as a result of sepsis partially related to CR.

CONCLUSIONS

Treatment with pegylated-interferon alpha-2a and ribavirin may trigger rapidly progressive CR in patients with therapeutic immunosuppressive trough levels, with or without first inducing ACR.

Active Drug Transport of Immunosuppressants

Immunosuppressants have a narrow therapeutic index, and pharmacokinetic variability negatively affects long-term outcome of transplantation. Recently, it has become clear that active transport is a major determinant of the inter-and intraindividual variability of the pharmacokinetics and pharmacodynamics of immunosuppressants. Active transport plays a key role in (1) the poor correlation between oral doses and systemic exposure of cyclosporine, tacrolimus, sirolimus, and everolimus, (2) tissue distribution including distribution into lymphocytes, (3) hepatic and intestinal metabolism, (4) the pharmacokinetic variability of immunosuppressants after oral dosing, (5) drug-drug interactions, (6) disease-drug interactions, and (7) age, gender, and ethnicity-based differences in pharmacokinetics of immunosuppressants. Those new insights may significantly improve patient management and long-term outcome not only by reducing pharmacokinetic variability and avoidance of drug-drug interactions but also by identification of sensitive patient populations. They will also significantly impact preclinical and clinical development strategies of new immunosuppressants.

Functional interactions between P-glycoprotein and CYP3A in drug metabolism

The interaction between drug-metabolising enzymes and active transporters is an emerging concept in pharmacokinetics. In the gut mucosa, P-glycoprotein and cytochrome P450 (CYP)3A functionally interact in three ways: i) drugs are repeatedly taken up and pumped out of the enterocytes by P-glycoprotein, thus increasing the probability of drugs being metabolised; ii) P-glycoprotein keeps intracellular drug concentrations within the linear range of the metabolising capacity of CYP3A; and iii) P-glycoprotein transports drug metabolites formed in the mucosa back into the gut lumen. In comparison with the gut mucosa, in hepatocytes the spatial sequence of CYP3A and P-glycoprotein is reversed, resulting in different effects when the activity of one or both are changed. CYP3A and P-glycoprotein are both regulated by nuclear receptors such as the pregnane X receptor (PXR). There is significant genetic variability of CYP3A, P-glycoprotein and PXR and their expression and activity is dependent on coadministered drugs, herbs, food, age, hormonal status and disease. Future pharmacogenomic and pharmacokinetic studies will have to take all three components into account to allow for valid conclusions.