Asunaprevir and daclatasvir for recurrent hepatitis C after liver transplantation: A Japanese multicenter experience

Analysis of Short-Term and Long-Term Outcomes of Living Donor Liver Transplantation for Patients with a High Model for End-Stage Liver Disease Score

BACKGROUND

The Model of End-Stage Liver Disease (MELD) scoring system can predict short-term survival among patients awaiting liver transplantation and is used to allocate organs prioritizing liver transplantation. Patients with high MELD scores have been reported to have worse early graft dysfunction and survival. However, recent studies have shown that patients with high MELD scores had satisfactory graft survival, although they showed more postoperative complications. In this study, we examined the effect of the MELD score on the short-term and long-term prognosis of living donor liver transplantation (LDLT).

METHODS

This study included 102 patients who underwent LDLT in our institution between 2005 and 2020. The patients were divided into 3 groups according to MELD score (low MELD group: ≤20, moderate MELD group: 21-30, and high MELD group: ≥31). Perioperative factors were compared among the 3 groups, and cumulative overall survival rates were calculated using the Kaplan-Meier method.

RESULTS

The patients' characteristics were comparable, and the median age was 54 years. Hepatitis C virus cirrhosis was the most common primary disease (n = 40), followed by hepatitis B virus (n = 11). The low MELD group consisted of 68 patients (median score: 16, 10-20); the moderate MELD group, 24 patients (median score: 24, 21-30); and the high MELD group, 10 patients (median score: 35, 31-40). The mean operative time (1241 min versus 1278 min versus 1158 min, P = .19) and mean blood loss (7517 mL vs 11162 mL vs 8808 mL, P = .71) were not significantly different among the 3 groups. The vascular and biliary complication rates were similar. The periods of intensive care unit and hospital stay tended to be longer in the high MELD group, but the difference was insignificant. The 1-year postoperative survival rate (85.3 % vs 87.5 % vs 90.0 %, P = .90) and overall survival rate were also not significantly different among the 3 groups.

CONCLUSIONS

Our study showed that LDLT patients with high MELD scores do not have a worse prognosis than those with low scores.

Antibody-Mediated Rejection and Recurrent Primary Disease: Two Main Obstacles in Abdominal Kidney, Liver, and Pancreas Transplants

The advances in acute phase care have firmly established the practice of organ transplantation in the last several decades. Then, the next issues that loom large in the field of transplantation include antibody-mediated rejection (ABMR) and recurrent primary disease. Acute ABMR is a daunting hurdle in the performance of organ transplantation. The recent progress in desensitization and preoperative monitoring of donor-specific antibodies enables us to increase positive outcomes. However, chronic active ABMR is one of the most significant problems we currently face. On the other hand, recurrent primary disease is problematic for many recipients. Notably, some recipients, unfortunately, lost their vital organs due to this recurrence. Although some progress has been achieved in these two areas, many other factors remain largely obscure. In this review, these two topics will be discussed in light of recent discoveries.

Dynamic changes of HCV genomes under selective pressure from DAAs therapy in relapsed patients

Currently, direct-acting antiviral drugs (DAAs) are widely used as therapeutic methods for hepatitis C virus (HCV)-positive patients, however, patients may experience treatment failure, and the dynamic changes of HCV genomes in these patients are unknown. In this study, three real-world DAAs cohorts were enrolled to observe clinical efficacy. In addition, serum samples from treatment failure patients at baseline and relapse were used to analyze changes of the HCV genomes at near full-length genome level, including resistance-associated variants (RAVs), viral quasispecies diversity and selection analysis. Next-generation sequencing was used as the detection method. The overall sustained virological response at 12 w after the end of treatment was achieved in 91.9% (57/62) of HCV patients, and 3 paired samples obtained from relapsed patients. All the 3 patients harbored baseline NS5A RAVs, the frequency of NS5A RAVs increased in 2 patients and a new NS5A RAV emerged in 1 patient at relapse, and almost all the viral strains existed with NS5A RAVs at relapse. The results of the viral quasispecies diversity analysis revealed that viral quasispecies diversity decreased at relapse compared to baseline, and the results of selection analysis indicated that the virus population experienced a bottleneck phenomenon, recent selective sweep and population expansion or was under purification selection after DAAs treatment. This study indicated that the clinical efficacy was excellent in real-world DAAs cohorts, and the viral strains existed at relapse were selective by DAAs therapy.

Recent advances in the treatment of hepatitis C virus infection for special populations and remaining problems

Hepatitis C virus (HCV) infection is one of the primary causes of liver cirrhosis, hepatocellular carcinoma (HCC), and liver transplantation (LT). The rate of HCV infection is high in patients on hemodialysis and in patients infected with human immunodeficiency virus (HIV). In liver transplant patients with HCV infection, recurrent HCV infection of the transplanted liver is universal and results in rapid liver fibrosis progression. In patients with HCV/HIV coinfection as well, liver fibrosis advances rapidly. Thus, there is an urgent need for prompt HCV infection treatment in these special populations (i.e. HIV/HCV coinfection, HCV infection after LT, and dialysis patients). Interferon (IFN)-based therapy for HCV infection could not achieve a high rate of sustained viral response and could cause severe adverse events in the aforementioned special populations. Direct-acting antivirals (DAAs) have recently been developed, and clinical trials have shown that IFN-free DAA-based therapies are associated with a significantly better safety and therapeutic profile than IFN-based therapies. However, the majority of the initial DAA trials excluded special populations; thus, the efficacy and safety of IFN-free DAA-based therapy in special populations remained to be clearly established. Although recent clinical trials and clinical studies have shown the high efficacy and safety of this therapy even in special populations, several unresolved problems, including emergence of resistance-associated variants after failure to respond to DAAs and HCC occurrence after DAA therapy, still exist. Hence, in this review, we discuss the recent advances in anti-HCV therapy for special populations and the remaining problems regarding this therapy.

Single-molecular real-time deep sequencing reveals the dynamics of multi-drug resistant haplotypes and structural variations in the hepatitis C virus genome

While direct-acting antivirals (DAAs) for hepatitis C virus (HCV) have dramatically progressed, patients still suffer from treatment failures. For the radical eradication of HCV, a deeper understanding of multiple resistance-associated substitutions (RASs) at the single-clone level is essential. To understand HCV quasispecies and their dynamics during DAA treatment, we applied single-molecule real-time (SMRT) deep sequencing on sera from 12 patients with genotype-1b HCV infections with DAA treatment failures, both pre- and post-treatment. We identified >3.2 kbp sequences between NS3 and NS5A genes of 187,539 clones in total, classifying into haplotype codes based on the linkage of seven RAS loci. The number of haplotype codes during the treatment, per sample, significantly decreased from 14.67 ± 9.12 to 6.58 ± 7.1, while the number of nonsynonymous codons on the seven RAS loci, per clone, significantly increased from 1.50 ± 0.92 to 3.64 ± 0.75. In five cases, the minority multi-drug resistant haplotypes at pre-treatment were identical to the major haplotypes at relapse. Moreover, various structural variations (SVs) were detected and their dynamics analysed. These results suggest that SMRT deep sequencing is useful for detecting minority haplotypes and SVs, and to evaluate the dynamics of viral genomes at the single-clone level.

Exploring the hepatitis C virus genome using single molecule real-time sequencing

Single molecular real-time (SMRT) sequencing, also called third-generation sequencing, is a novel sequencing technique capable of generating extremely long contiguous sequence reads. While conventional short-read sequencing cannot evaluate the linkage of nucleotide substitutions distant from one another, SMRT sequencing can directly demonstrate linkage of nucleotide changes over a span of more than 20 kbp, and thus can be applied to directly examine the haplotypes of viruses or bacteria whose genome structures are changing in real time. In addition, an error correction method (circular consensus sequencing) has been established and repeated sequencing of a single-molecule DNA template can result in extremely high accuracy. The advantages of long read sequencing enable accurate determination of the haplotypes of individual viral clones. SMRT sequencing has been applied in various studies of viral genomes including determination of the full-length contiguous genome sequence of hepatitis C virus (HCV), targeted deep sequencing of the HCV NS5A gene, and assessment of heterogeneity among viral populations. Recently, the emergence of multi-drug resistant HCV viruses has become a significant clinical issue and has been also demonstrated using SMRT sequencing. In this review, we introduce the novel third-generation PacBio RSII/Sequel systems, compare them with conventional next-generation sequencers, and summarize previous studies in which SMRT sequencing technology has been applied for HCV genome analysis. We also refer to another long-read sequencing platform, nanopore sequencing technology, and discuss the advantages, limitations and future perspectives in using these third-generation sequencers for HCV genome analysis.

Efficacy and safety of glecaprevir and pibrentasvir treatment for 8 or 12 weeks in patients with recurrent hepatitis C after liver transplantation: a Japanese multicenter experience

BACKGROUND

Efficacy of 8-week regimen with direct-acting antivirals (DAA) for patients with hepatitis C after liver transplantation has not been clarified. This study aimed to clarify the efficacy and safety of glecaprevir and pibrentasvir therapy for 8 and 12 weeks in Japanese patients with recurrent hepatitis C after liver transplantation.

METHODS

A cohort study of liver transplant recipients with recurrent hepatitis C treated with glecaprevir (300 mg/day) and pibrentasvir (120 mg/day) was performed at nine liver transplant centers in Japan.

RESULTS

Twenty-five patients with hepatitis C after liver transplantation were treated with glecaprevir and pibrentasvir. Twenty-four patients completed the treatment protocol; treatment was discontinued in one patient who had nausea at 3 days after the initiation of treatment. All the 24 patients who completed the 8- or 12-week treatment protocol achieved a sustained virological response 12 weeks after completion of treatment (SVR12). The SVR12 rates in patients with HCV genotype 1 and 2 were 100% (21 of 21 patients) and 75% (3 of 4 patients), respectively. All patients with prior DAA therapy failure (n = 6), jaundice (n = 4), and liver cirrhosis (n = 4) achieved SVR12. Seven of 8 patients (88%) with severe renal impairment achieved SVR12. Adverse events occurred in 6 of 25 patients (24%), including serious adverse events in 2 patients (8%). Treatment-related adverse events were nausea, pruritus, and mild renal dysfunction.

CONCLUSIONS

Eight- or 12-week regimen of glecaprevir and pibrentasvir is efficacious and safe in patients with recurrent HCV infection after liver transplantation, even in difficult-to-treat populations, including patients with severe renal impairment, prior DAA experience, liver cirrhosis, or jaundice after liver transplantation.

Direct-acting antiviral agents for liver transplant recipients with recurrent genotype 1 hepatitis C virus infection: Systematic review and meta-analysis

Background

Comprehensive evaluation of safety and efficacy of different combinations of direct‐acting antivirals (DAAs) in liver transplant recipients with genotype 1 (GT1) hepatitis C virus (HCV) recurrence remains limited. Therefore, we performed this systematic review and meta‐analysis in order to evaluate the clinical outcome of DAA treatment in liver transplant patients with HCV GT1 recurrence.

Methods

Studies were included if they contained information of 12 weeks sustained virologic response (SVR12) after DAA treatment completion as well as treatment related complications for liver transplant recipients with GT1 HCV recurrence.

Results

We identified 16 studies comprising 885 patients. The overall pooled estimate proportion of SVR12 was 93% (95% confidence interval (CI): 0.89, 0.96), with moderate heterogeneity observed (τ² = 0.01, P < 0.01, I²=75%). High tolerability was observed in liver transplant recipients reflected by serious adverse events (sAEs) with pooled estimate proportion of 4% (95% CI: 0.01, 0.07; τ² = 0.02, P < 0.01, I² = 81%). For subgroup analysis, a total of five different DAA regimens were applied for treating these patients. Sofosbuvir/Ledipasvir (SOF/LDV) led the highest pooled estimate SVR12 proportion, followed by Paritaprevir/Ritonavir/Ombitasivir/Dasabuvir (PrOD), Daclatasvir (DCV)/Simeprevir (SMV) ± Ribavirin (RBV), and SOF/SMV ± RBV, Asunaprevir (ASV)/DCV. There was a tendency for favoring a higher pooled SVR12 proportion in patients with METAVIR Stage F0‐F2 of 97% (95% CI: 0.93, 0.99) compared to 85% (95% CI: 0.79, 0.90) for stage F3‐F4 (P < 0.01). There was no significant difference between LT recipients treated with or without RBV (P = 0.23).

Conclusions

Direct‐acting antiviral treatment is highly effective and well‐tolerated in liver transplant recipients with recurrent GT1 HCV infection.

Interaction of immunosuppressants with HCV antivirals daclatasvir and asunaprevir: combined effects with mycophenolic acid

AIM

To investigate the specific effects of immunosuppressants on the antiviral action of daclatasvir and asunaprevir.

METHODS

The antiviral activity of daclatasvir (DCV) and asunaprevir (ASV) combined with immunosuppressants was tested using two in vitro models for hepatitis C virus (HCV) infection.

RESULTS

Tacrolimus, rapamycin and cyclosporine did not negatively affect the antiviral action of DCV or ASV. Mycophenolic acid (MPA) showed additive antiviral effects combined with these direct acting antivirals (DAAs). MPA induces interferon-stimulated genes (ISGs) and is a potent GTP synthesis inhibitor. DCV or ASV did not induce ISGs expression nor affected ISG induction by MPA. Rather, the combined antiviral effect of MPA with DCV and ASV was partly mediated via inhibition of GTP synthesis.

CONCLUSION

Immunosuppressants do not negatively affect the antiviral activity of DAAs. MPA has additive effect on the antiviral action of DCV and ASV. This combined benefit needs to be confirmed in prospective clinical trials.

Treatment of hepatitis C in special populations

Hepatitis C virus (HCV) infection is one of the primary causes of liver cirrhosis and hepatocellular carcinoma. In hemodialysis patients, the rate of HCV infection is high and is moreover associated with a poor prognosis. In liver transplantation patients with HCV infection, recurrent HCV infection is universal, and re-infected HCV causes rapid progression of liver fibrosis and graft loss. Additionally, in patients with HCV and human immunodeficiency virus (HIV) co-infection, liver fibrosis progresses rapidly. Thus, there is an acute need for prompt treatment of HCV infection in these special populations (i.e., hemodialysis, liver transplantation, HIV co-infection). However, until recently, the standard anti-HCV treatment involved the use of interferon-based therapy. In these special populations, interferon-based therapies could not achieve a high rate of sustained viral response and moreover were associated with a higher rate of adverse events. With the development of novel direct-acting antivirals (DAAs), the landscape of anti-HCV therapy for special populations has changed dramatically. Indeed, in special populations treated with interferon-free DAAs, the sustained viral response rate was above 90%, with a lower incidence and severity of adverse events.