The impact of directly acting antivirals on the enzymatic liver function of liver transplant recipients with recurrent hepatitis C

Long-Term Impact of Direct-Acting Antivirals on Liver Fibrosis and Survival in HCV-Infected Liver Transplant Recipients

(1) Background: Little is known about the long-term impact of sustained virological response (SVR) on fibrosis progression and patient survival in liver transplantation (LT) recipients treated with direct-acting antivirals (DAAs). We investigated liver fibrosis evolution and patient survival in hepatitis C virus (HCV)-infected patients receiving DAAs after LT. (2) Methods: All consecutive HCV-infected patients treated with DAAs after LT between May 2014 and January 2019 were considered. The clinical and virological features were registered at the baseline and during the follow-up. The liver fibrosis was assessed by liver biopsy and/or transient elastography (TE) at the baseline and at least 1 year after the end of treatment (EoT). (3) Results: A total of 136 patients were included. The SVR12 was 78% after the first treatment and 96% after retreatment. After the SVR12, biochemical tests improved at the EoT and remained stable throughout the 3-year follow-up. Liver fibrosis improved after the SVR12 (p < 0.001); nearly half of the patients with advanced liver fibrosis experienced an improvement of an F ≤ 2. The factors associated with lower survival in SVR12 patients were the baseline platelet count (p = 0.04) and creatinine level (p = 0.04). (4) Conclusions: The long-term follow-up data demonstrated that SVR12 was associated with an improvement in hepatic function, liver fibrosis, and post-LT survival, regardless of the baseline liver fibrosis. The presence of portal hypertension before the DAAs has an impact on patient survival, even after SVR12.

Effectiveness and safety of generic and brand direct acting antivirals for treatment of chronic hepatitis C

BACKGROUND

Direct acting antivirals (DAAs) are a very effective treatment for hepatitis C virus (HCV). However, brand DAAs are expensive. The licensing of cheaper generic DAAs may address this issue, but there is a lack of clinical studies comparing the efficacy of generic vs brand DAA formulations.

AIM

To compare the efficacy and safety of generic against brand DAAs for chronic hepatitis C treatment in Bahrain.

METHODS

This was a retrospective observational study involving 289 patients with chronic HCV infection during 2016 to 2018. There were 149 patients who were treated with brand DAAs, while 140 patients were treated with generic DAAs. Commonly used DAAs were Ombitasvir/Paritaprevir/Ritonavir ± Dasabuvir ± Ribavirin, and Sofosbuvir/Daclatasvir ± Ribavirin. SVR at 12 wk post treatment was the main outcome variable.

RESULTS

Overall, 87 patients (30.1%) had cirrhosis and 68.2% had genotype 1 HCV infection. At 12 wk post treatment, SVR was achieved by 271 (93.8%) of the patients. In patients who were treated with generic medications, 134 (95.7%) achieved SVR at 12 wk post treatment, compared to 137 (91.9%) among those treated with brand medications (P = 0.19). Having cirrhosis [odds ratio (OR): 9.41, 95% confidence interval (CI): 2.47–35.84] and having HCV genotype 3 (OR: 3.56, 95%CI: 1.03–12.38) were significant independent predictors of not achieving SVR. Alanine transaminase, gamma-glutamyl transpeptidase, and total bilirubin levels decreased significantly following therapy with both generic and brand DAAs.

CONCLUSION

Generic and brand DAAs demonstrate comparable effectiveness in the treatment of chronic hepatitis C patients. Both are safe and equally effective in improving biochemical markers of hepatic inflammation.

Influence of Inflammation on Cytochromes P450 Activity in Adults: A Systematic Review of the Literature

Background: Available in-vitro and animal studies indicate that inflammation impacts cytochromes P450 (CYP) activity via multiple and complex transcriptional and post-transcriptional mechanisms, depending on the specific CYP isoforms and the nature of inflammation mediators. It is essential to review the current published data on the impact of inflammation on CYP activities in adults to support drug individualization based on comorbidities and diseases in clinical practice. Methods: This systematic review was conducted in PubMed through 7th January 2021 looking for articles that investigated the consequences of inflammation on CYP activities in adults. Information on the source of inflammation, victim drugs (and CYPs involved), effect of disease-drug interaction, number of subjects, and study design were extracted. Results: The search strategy identified 218 studies and case reports that met our inclusion criteria. These articles were divided into fourteen different sources of inflammation (such as infection, autoimmune diseases, cancer, therapies with immunomodulator…). The impact of inflammation on CYP activities appeared to be isoform-specific and dependent on the nature and severity of the underlying disease causing the inflammation. Some of these drug-disease interactions had a significant influence on drug pharmacokinetic parameters and on clinical management. For example, clozapine levels doubled with signs of toxicity during infections and the concentration ratio between clopidogrel's active metabolite and clopidogrel is 48-fold lower in critically ill patients. Infection and CYP3A were the most cited perpetrator of inflammation and the most studied CYP, respectively. Moreover, some data suggest that resolution of inflammation results in a return to baseline CYP activities. Conclusion: Convincing evidence shows that inflammation is a major factor to be taken into account in drug development and in clinical practice to avoid any efficacy or safety issues because inflammation modulates CYP activities and thus drug pharmacokinetics. The impact is different depending on the CYP isoform and the inflammatory disease considered. Moreover, resolution of inflammation appears to result in a normalization of CYP activity. However, some results are still equivocal and further investigations are thus needed.

Impact of Inflammation on Cytochromes P450 Activity in Pediatrics: A Systematic Review

Background and Objective

Cytochromes P450 (CYP) are the major enzymes involved in hepatic metabolism of drugs. Personalization of treatment in pediatrics is a major challenge, as it must not only take into account genetic, environmental, and physiological factors but also ontogeny. Published data in adults show that inflammation had an isoform-specific impact on CYP activities and we aimed to evaluate this impact in the pediatric population.

Methods

Articles listed in PubMed through 7 January, 2021 that studied the impact of inflammation on CYP activities in pediatrics were included in this systematic review. Sources of inflammation, victim drugs (CYP involved), effect of drug–disease interactions, number and age of subjects, and study design were extracted.

Results

Twenty-seven studies and case reports were included. The impact of inflammation on CYP activities appeared to be age dependent and isoform-specific, with some drug–disease interactions having significant pharmacokinetic and clinical impact. For example, midazolam clearance decreases by 70%, while immunosuppressant and theophylline concentrations increase three-fold and two-fold with intensive care unit admission and infection. Cytochrome P450 activity appears to return to baseline level when the disease is resolved.

Conclusions

Studies that have assessed the impact of inflammation on CYP activity are lacking in pediatrics, yet it is a major factor to consider to improve drug efficacy or safety. The scarce current data show that the impact of inflammation is isoform and age dependent. An effort must be made to improve the understanding of the impact of inflammation on CYP activities in children to better individualize treatment.

Treatment of hepatitis C in two paediatric patients using sofosbuvir during haematopoietic stem cell transplantation

We report the first two paediatric cases of sofosbuvir treatment during high-intensity myeloablative conditioning and engraftment phases of haematopoietic stem cell transplantation. These reports highlight the safety of sofosbuvir during all phases of transplantation and the lack of interaction between sofosbuvir and alkylating or immunosuppressive agents.

Clinical efficacy of direct-acting antiviral therapy for recurrent hepatitis C virus infection after liver transplantation in patients with hepatocellular carcinoma

BACKGROUND

Recurrent hepatitis C virus (HCV) infection of transplanted liver allografts is universal in patients with detectable HCV viremia at the time of transplantation. Direct-acting antiviral (DAA) therapy has been adopted as the standard of care for recurrent HCV infection in the post-transplant setting. However, there are insufficient data regarding its efficacy in liver transplant (LT) recipients with a history of hepatocellular carcinoma (HCC), and the risk of HCC recurrence after DAA therapy is unknown.

AIM

To demonstrate predictors of DAA treatment failure and HCC recurrence in LT recipients.

METHODS

A total of 106 LT recipients given DAAs for recurrent HCV infection from 2015 to 2019 were identified (68 with and 38 without HCC). Descriptive statistics and logistic regression models were used to estimate the multivariate odds ratios and respective 95% confidence intervals for predictors of treatment failure and HCC recurrence.

RESULTS

Six patients (6%) experienced DAA therapy failure post-LT and 100 (94%) had a sustained virologic response at follow-up week 12. A high alanine transaminase level > 35 U/L at treatment week 4 was a significant predictor of treatment failure. Relapse to pre-LT DAA therapy is a predictor of post-LT HCC recurrence, P = 0.04. DAA relapse post-LT was also associated with post-transplantation HCC recurrence, P = 0.05.

CONCLUSION

DAAs are effective and safe in the treatment of recurrent HCV infection in LT recipients with history of HCC. Relapse to pre- and post-LT DAA therapy is associated with post-transplantation HCC recurrence.

Management and tolerability of glecaprevir-pibrentasvir pharmacotherapy in hepatitis C viremic heart and lung transplant recipients

We conducted a retrospective review of thoracic transplant recipients (22 heart and 16 lung transplant recipients) prospectively enrolled in a single-center observational study of HCV NAT+ organ transplantation in HCV NAT- recipients. All recipients were treated with 8 weeks of glecaprevir-pibrentasvir (GP) for HCV viremia in addition to standard triple immunosuppression post-transplant. Thoracic transplant recipients of HCV NAT- organs were used as a control (24 heart and 22 lung transplant recipients). Our primary outcome was to assess the effect of GP on tacrolimus dose requirements. Secondary objectives included assessing drug interactions with common post-transplant medications, adverse effects, and the need to hold or discontinue GP therapy. The median tacrolimus concentration-to-dose ratio (CDR) in the cohort was 184 (99-260) during GP therapy and 154 (78-304) over the first month after GP (P = .79). Trends in median tacrolimus CDR were similar on a per-week basis and per-patient basis. In three instances, concomitant posaconazole and GP led to hyperbilirubinemia and interruption of posaconazole. GP therapy was held in one heart transplant recipient and discontinued in another due to unresolving hyperbilirubinemia. Utilization of GP to treat HCV viremia post-thoracic transplant is feasible and safe, but requires modifications to post-transplant pharmacotherapy and careful monitoring for adverse effects.

Raltegravir pharmacokinetics before and during treatment with ombitasvir, paritaprevir/ritonavir plus dasabuvir in adults with human immunodeficiency virus-1 and hepatitis C virus coinfection: AIDS Clinical Trials Group sub-study A5334s

AIMS

AIDS Clinical Trials Group study A5334s evaluated the pharmacokinetics of raltegravir before and during combined administration of ombitasvir, paritaprevir/ritonavir, plus dasabuvir (OBV/PTV/r + DSV) and weight-based ribavirin in human immunodeficiency virus (HIV) and hepatitis C virus (HCV) coinfected adults. The pharmacokinetics of OBV/PTV/r + DSV during raltegravir coadministration were also characterized.

METHODS

Adults living with HIV/HCV coinfection receiving steady-state raltegravir (400 mg twice daily) with 2 nucleos(t)ide analogues were enrolled. Pharmacokinetics of raltegravir were assessed prior to HCV therapy, and 4 weeks later following initiation of OBV/PTV/r (25/150/100 mg) once daily + DSV (250 mg) twice daily. Geometric mean ratios (GMRs) and 90% confidence intervals (CIs) were used to compare the following: raltegravir pharmacokinetics with HCV therapy (week 4) vs before HCV therapy (week 0); OBV/PTV/r and DSV pharmacokinetics vs historical healthy controls; raltegravir pharmacokinetics at week 0 vs historical control adults living with HIV.

RESULTS

Eight of 11 participants had decreased raltegravir exposures after initiation of HCV therapy. The GMRs (90% CI) for maximum concentration and area under the concentration-time curve of raltegravir with vs without HCV therapy were 0.68 (0.38-1.19) and 0.82 (0.58-1.17), respectively. Comparing OBV/PTV/r pharmacokinetics in healthy controls, A5334s study participants demonstrated generally lower maximum concentration and area under the concentration-time curve values by 41-82% and 4-73%, respectively. Raltegravir exposures tended to be higher in A5334s study participants compared to adults living with HIV.

CONCLUSIONS

The majority of participants' plasma raltegravir exposures were lower after initiation of HCV therapy in coinfected adults; however, confidence intervals were wide.

International Liver Transplantation Society Asian Consensus on the Management of Hepatitis C Virus Infection in Resource Limited Setting-From Noncirrhotic to Decompensated Disease and After Liver Transplantation

BACKGROUND

The population of Asia exceeds 4.4 billion people. Chronic hepatitis C virus (HCV) infection in Asia is characterized by specific distribution of genotypes, lack of access to specific therapeutic agents, relatively high cost of treatment, and lack of experienced healthcare providers. Clear consensus on the diagnosis, management, and monitoring of HCV infection specific to the Asian region is a major unmet need. The consensus guidelines documents that have been published to date by major medical societies presume access to an array of direct acting antiviral agents and diagnostic tests that are not broadly applicable to resource limited settings, including Asia.

METHODS

To address the lack of an Asia-specific set of HCV treatment guidelines, we assembled a panel of 15 HCV experts in the field of hepatology from India, Indonesia, Myanmar, Vietnam, Pakistan, Philippines, and Mongolia convened in April 2017 to review the updated literature and provide recommendations on the diagnosis and management of chronic HCV infection that reflects local conditions.

RESULTS

An evidence-based comprehensive compilation of the literature supported by the graded recommendations from the expert panel for the optimization of the diagnosis, pretreatment, on treatment, and posttreatment assessments, and management of chronic HCV infection has been presented in this article.

CONCLUSIONS

With the evolving treatment landscape and addition of several new direct-acting antiviral agents and combination regimens into the therapeutic armamentarium, the current article may serve as a guide to the clinicians in optimizing the diagnosis and treatment selection for the management of chronic HCV infection in resource-limited settings.

Comparison of the effect of direct-acting antiviral with and without ribavirin on cyclosporine and tacrolimus clearance values: results from the ANRS CO23 CUPILT cohort

PURPOSE

Direct-acting antiviral agents have demonstrated their efficacy in treating HCV recurrence after liver transplantation and particularly the sofosbuvir/daclatasvir combination. Pharmacokinetic data on both calcineurin inhibitors and direct-acting antiviral exposure in liver transplant recipients remain sparse.

METHODS

Patients were enrolled from the ANRS CO23 CUPILT cohort. All patients treated with sofosbuvir/daclatasvir with or without ribavirin were included in this study when blood samples were available to estimate the clearance of immunosuppressive therapy before direct-acting antiviral initiation and during follow-up. Apparent tacrolimus and cyclosporine clearances were estimated from trough concentrations measured using validated quality control assays.

RESULTS

Sixty-seven mainly male patients (79%) were included, with a mean age of 57 years and mean MELD score of 8.2; 50 were on tacrolimus, 17 on cyclosporine. Ribavirin was combined with sofosbuvir/daclatasvir in 52% of patients. Cyclosporine clearance remained unchanged as well as tacrolimus clearance under the ribavirin-free regimen. Tacrolimus clearance increased 4 weeks after direct-acting antivirals and ribavirin initiation versus baseline (geometric mean ratio 1.81; 90% CI 1.30-2.52). Patients under ribavirin had a significantly higher fibrosis stage (> 2) (p = 0.02) and lower haemoglobin during direct-acting antiviral treatment (p = 0.02) which impacted tacrolimus measurements. Direct-acting antiviral exposure was within the expected range.

CONCLUSION

Our study demonstrated that liver transplant patients with a recurrence of hepatitis C who are initiating ribavirin combined with a sofosbuvir-daclatasvir direct-acting antiviral regimen may be at risk of lower tacrolimus concentrations because of probable ribavirin-induced anaemia and higher fibrosis score, although there are no effects on cyclosporine levels.

TRIAL REGISTRATION

NCT01944527.

A Downside to Hepatitis C Virus Cure? Vigilance Is Needed Regarding Hepatitis B Virus Reactivation, Organ Rejection, or Hepatocellular Carcinoma Progression

Cure of hepatitis C virus has become feasible in almost all patients. However, vigilance is needed in 3 scenarios: previous exposure to hepatitis B virus (HBV), history of organ transplantation, and history of cured hepatocellular carcinoma (HCC). The current data suggest that HBV reactivation occurs in about 10% of hepatitis B surface antigen (HBsAg)-positive patients and approximately 1% of hepatitis B core antibody-positive but HBsAg-negative patients. The risk of organ rejection is also around 1%, but can be fatal if not acted on immediately. Finally, the risk of early HCC recurrence may be increased but should not delay initiation of antiviral therapy in the setting of cured HCC; however, increased surveillance may be warranted.

Impact of direct-acting antivirals for hepatitis C virus therapy on tacrolimus dosing in liver transplant recipients

INTRODUCTION

Direct-acting antivirals (DAAs) have transformed hepatitis C virus (HCV) management post-liver transplant. As HCV clears during DAA treatment, hepatic metabolism improves, resulting in decreased tacrolimus concentrations that may require dose adjustment. The purpose of this study was to determine appropriate management of immunosuppression in liver transplant recipients during and following treatment of HCV.

METHODS

This study was a single-center retrospective analysis of 71 liver transplant recipients who were treated for HCV with DAAs. The primary outcome was change in dose-normalized tacrolimus concentrations from the start of DAA treatment to 12 weeks following therapy.

RESULTS

The mean change in log-transformed dose-normalized tacrolimus concentrations was a reduction of 0.43 ng/mL/mg (95% CI; 0.26-0.60, P < 0.0001). The greatest decrease occurred in the first 4 weeks of treatment, after which levels stabilized. The overall mean tacrolimus concentration was 4.8 ng/mL (±2.5). Two patients (3%) developed acute cellular rejection and two patients (3%) had graft loss and died.

CONCLUSION

From the start of treatment to 12 weeks post-DAA therapy, liver transplant recipients experienced a significant decrease in dose-normalized tacrolimus concentrations. In conclusion, close monitoring of tacrolimus concentrations is warranted during and following treatment with DAAs, as dose increases may be indicated in order to maintain therapeutic concentrations to prevent graft rejection.

Evaluation of histological dynamics, kidney function and diabetes in liver transplant patients after antiviral treatment with direct-acting antivirals: Therapy of HCV-recurrence

BACKGROUND

Direct-acting antivirals allow efficient and safe treatment of hepatitis C (HCV) before and after liver transplantation (LT). However, the impact of sofosbuvir on the graft, diabetes, and on kidney function is not answered yet. Primary endpoint of this analysis was the evaluation of kidney function after antiviral treatment (AVT). Secondary endpoints were the assessment of extrahepatic manifestation of HCV-infection by diabetes mellitus and the histopathological changes in terms of inflammation, content of fat, and fibrosis stage.

METHODS

From 2014 to 4/2015, 100 patients with HCV-recurrence after LT were successfully treated with AVT. Ninety-eight received a sofosbuvir-based regimen. Indication was based on genotype, transplant fibrosis stage, and urgency. Biopsies were evaluated before and after treatment. Renal function and diabetes were assessed before, during, and after AVT.

RESULTS

All patients achieved sustained virological response. A significant improvement of inflammation (P = 0.001) and fibrosis stage (P = 0.031) were observed. Significantly less insulin was required in 32 patients with diabetes (P < 0.001) to keep Hb1Ac unchanged after AVT. Kidney function was stable during, 12 weeks after and 48 weeks after antiviral therapy. Stages of renal insufficiency were comparable before and after AVT.

CONCLUSION

Successful sofosbuvir-based AVT leads to a variety of positive development in transplant patients including a significant improvement of inflammation, fat content and fibrosis, a significant decrease in daily insulin dose and no significant impairment of kidney function.

Sofosbuvir, Velpatasvir, and Voxilaprevir for Treatment of Recurrent Hepatitis C Virus Infection After Liver Transplantation

There are limited data on direct-acting antiviral (DAA) treatment options for previously treated patients with recurrent genotype 3 (GT3) hepatitis C virus (HCV) after liver transplantation. Sofosbuvir/velpatasvir/voxilaprevir (SOF/VEL/VOX) is currently approved for treatment of HCV in patients with prior treatment with DAAs. We report the first published experience using SOF/VEL/VOX after liver transplantation for a DAA-experienced patient with severe hepatitis due to early recurrent GT3 HCV. The patient was treated with SOF/VEL/VOX that was extended to a total duration of 16 weeks and was intensified with ribavirin (RBV) starting at week 8 due to persistent viremia during treatment. Sustained virologic response at 12 weeks (SVR12) after treatment completion was achieved. SOF/VEL/VOX was well tolerated, and immediate drug-drug interaction (DDI) with tacrolimus (TAC) was not evident. Due to improvement in liver metabolic function with increasing TAC clearance, TAC dose adjustment was required throughout the treatment course. Conclusion: SOF/VEL/VOX can be considered for treatment of recurrent HCV after transplantation. Further study is needed to establish safety and efficacy and define treatment duration in difficult-to-treat populations.

High efficacy of generic and brand direct acting antivirals in treatment of chronic hepatitis C

BACKGROUND

Direct acting antivirals (DAAs) are highly effective for treatment of hepatitis C (HCV) but brand products are priced beyond the means of most low and middle income countries (LMICs). Although a few DAAs are offered at reduced prices in access programs, they are still beyond affordability in limited resource settings with a large HCV infected population. Cheap generics might fill this economic need, but studies comparing their clinical efficacy to that of original products are limited.

AIM

To compare efficacy of brand and generic DAAs used in the national treatment program in Egypt.

METHODS

HCV treatment eligible patients (n=971) were enrolled. They were treated with 12 weeks of either sofosbuvir-daclatasvir (SOF-DCV) or SOF-ledipasvir (SOF-LDV). Ribavirin (RBV) was added to patients with cirrhosis and to SOF experienced patients. Patients with cirrhosis who were RBV intolerant were treated for 24 weeks without RBV.

RESULTS

Most patients were males (61.4%), treatment naïve (88.6%), without cirrhosis (61.7%), and the mean age was 51.3±11.31 years. Baseline characteristics were not different in patients treated with brand or generic medications regarding age, liver tests, creatinine, platelets, MELD score, baseline HCV-RNA and transient elastography. Overall sustained virologic response (SVR) rate was 98.1%, which was similar for generic and brand drugs (98.2% vs. 98.1%; p=1), and similar with both regimens used (SOF-DCV±RBV: brand: 98.1%, generic 97.8%; p=0.729, SOF-LDV±RBV: brand 98.2%, generic 100%; p=0.729). AST and ALT decreased significantly with initiation of therapy with both generic and original drugs.

CONCLUSION

Generic and brand DAAs are equally effective for achieving SVR and improving aminotransferases.

Randomized clinical trial comparing liver resection with and without perioperative assessment of liver function

Background

Liver function tests may help to predict outcomes after liver surgery. The aim of this study was to evaluate the clinical impact on postoperative outcome and patient management of perioperative liver function testing using the LiMAx^® test.

Methods

A multicentre RCT was conducted in six academic liver centres. Patients with intrahepatic tumours scheduled for open liver resection of at least one segment were eligible. Patients were randomized to undergo additional perioperative liver function tests (LiMAx^® group) or standard care (control group). Patients in the intervention arm received two perioperative LiMAx^® tests, one before the operation for surgical planning and another after surgery for postoperative management. The primary endpoint was the proportion of patients transferred directly to a general ward. Secondary endpoints were severe complications, length of hospital stay (LOS) and length of intermediate care/ICU (LOI) stay.

Results

Some 148 patients were randomized. Thirty‐six of 58 patients (62 per cent) in the LiMAx^® group were transferred directly to a general ward, compared with one of 60 (2 per cent) in the control group (P < 0·001). The rate of severe complications was significantly lower in the LiMAx^® group (14 per cent versus 28 per cent in the control group; P = 0·022). LOS and LOI were significantly shorter in the LiMAx^® group (LOS: 10·6 versus 13·3 days respectively, P = 0·012; LOI: 0·8 versus 3·0 days, P < 0·001).

Conclusion

Perioperative use of the LiMAx^® test improves postoperative management and reduces the incidence of severe complications after liver surgery. Registration number: NCT01785082 ( https://clinicaltrials.gov).

The Predictive Value of the Maximal Liver Function Capacity Test for the Isolation of Primary Human Hepatocytes

The need for primary human hepatocytes is constantly growing for basic research, as well as for therapeutic applications. However, the isolation outcome strongly depends on the quality of liver tissue, and we are still lacking a preoperative test that allows the prediction of the hepatocyte isolation outcome. In this study, we evaluated the "maximal liver function capacity test" (LiMAx) as predictive test for the quantitative and qualitative outcome of hepatocyte isolation. This test is already used in clinical routine to measure preoperative and to predict postoperative liver function. The patient's preoperative mean LiMAx was obtained from the patient records, and preoperative computed tomography and magnetic resonance images were used to calculate the whole liver volume to adjust the mean LiMAx. The outcome parameters of the hepatocyte isolation procedures were analyzed in correlation with the adjusted mean LiMAx. Primary human hepatocytes were isolated from partial hepatectomies (n = 64). From these 64 hepatectomies we included 48 to our study and correlated their isolation outcome parameters with volume corrected LiMAx values. From a total of 11 hepatocyte isolation procedures, metabolic parameters (albumin, urea, and aspartate aminotransferase or AST) were assessed during the hepatocyte cultivation period of 5 days. The volume adjusted mean LiMAx showed a significant positive correlation with the total cell yield (p = 0.049; r = 0.242; n = 48). The correlations of volume adjusted LiMAx values with viable cell yield and cell viability did not reach statistical significance. To create a more homogenous study group regarding tumor entities, subgroup analyses were performed. A subgroup analysis of isolations from patients with colorectal metastasis revealed a significant correlation between volume adjusted mean LiMAx and total cell yield (p = 0.012; r = 0.488; n = 21) and viable cell yield (p = 0.034; r = 0.405; n = 21), whereas a subgroup analysis of isolations of patients with carcinoma of the biliary tree showed significant correlations of volume adjusted mean LiMAx with cell viability (r = 0.387; p = 0.046; n = 20) and lacked significant correlations with total cell yield (r = -0.060; p = 0.401; n = 20) and viable cell yield (r = 0.012; p = 0.480; n = 20). The volume-adjusted mean LiMAx did not show a significant correlation with any of the metabolic parameters. In conclusion, the LiMAx test might be a useful tool to predict the quantitative outcome of hepatocyte isolation, as long as underlying liver disease is taken into consideration.

Direct-acting antiviral agent efficacy and safety in renal transplant recipients with chronic hepatitis C virus infection: A PRISMA-compliant study

BACKGROUND

The efficacy and safety of direct-acting antivirals (DAAs) for treating hepatitis C virus (HCV)-infected renal transplant recipients (RTRs) has not been determined.

METHODS

We searched PubMed, Embase, and the Cochrane Central Register of Controlled Trials and assessed the quality of eligible studies using the Joanna Briggs Institute scale. DAA efficacy and safety were assessed using standard mean difference (SMD) with 95% confidence intervals (95%CIs).

RESULTS

Six studies (360 RTRs) were included. Two hundred thirty six RTRs (98.3%) achieved sustained virological response within 12 weeks; HCV infection was cleared in 239 RTRs after 24-week treatment. Liver function differed significantly pre- and posttreatment (alanine aminotransferase, SMD: 0.96, 95%CIs: 0.65, 1.26; aspartate aminotransferase, SMD: 0.89, 95%CIs: 0.60, 1.18); allograft function pre- and posttreatment was not statistically different (serum creatinine, SMD: -0.13, 95%CIs: -0.38, 0.12; estimated glomerular filtration rate, SMD: 0.20, 95%CIs: -0.11, 0.51). General symptoms (fatigue nausea dizziness or headache) were the most common adverse events (AEs) (39.3%). Severe AEs, that is, anemia, portal vein thrombosis, and streptococcus bacteraemia and pneumonia, were present in 1.1%, 0.6%, and 1.1% of RTRs, respectively.

CONCLUSION

Our findings suggest that DAAs are highly efficacious and safe for treating HCV-infected RTRs and without significant AE.

Decreased tacrolimus plasma concentrations during HCV therapy: a drug-drug interaction or is there an alternative explanation?

Chronic hepatitis C virus (HCV) infection can cause severe liver cirrhosis, for which liver transplantation is the only therapy. To prevent organ rejection, transplanted patients are treated with immunosuppressive agents. We describe two transplanted patients treated with tacrolimus who were simultaneously treated with direct-acting antivirals (DAAs) for their chronic HCV infection. No pharmacokinetic drug-drug interactions (DDIs) were expected between tacrolimus and the selected DAAs. However, in both patients, tacrolimus plasma concentrations decreased during HCV treatment. We hypothesise that decreased plasma concentrations were not caused by a DDI but were an indirect result of the clearance of the HCV infection. During chronic HCV infection, pro-inflammatory cytokines may inhibit cytochrome P450 (CYP) enzymes, which are primarily responsible for tacrolimus metabolism. If this is true, then with clearance of the virus the activity of these enzymes will normalise and tacrolimus metabolism will increase. These changes were clinically relevant because the tacrolimus dosage needed to be adjusted. Therefore, physicians should be aware that CYP substrates with narrow therapeutic ranges might require dose adaption during HCV therapy with DAAs.