Hepatitis E virus mutations associated with ribavirin treatment failure result in altered viral fitness and ribavirin sensitivity

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• 作者：Yannick Debing¹ ; ^&dagger ; ; Christophe Ramiè ; re² ; ³ ; ⁴ ; ⁵ ; ^&dagger ; ; Kai Dallmeier¹ ; Gé ; raldine Piorkowski⁶ ; Mary-Anne Trabaud² ; Fanny Lebossé ; ⁴ ; ⁵ ; ⁷ ; ⁸ ; Caroline Scholtè ; s² ; ³ ; ⁴ ; ⁵ ; Magali Roche⁹ ; Catherine Legras-Lachuer⁹ ; ¹⁰ ; Xavier de Lamballerie⁶ ; ¹¹ ; Patrice André ; ² ; ³ ; ⁴ ; ⁵ ; ^&Dagger ; ; Johan Neyts¹ ; ^&Dagger ; ; ^{johan.neyts@rega.kuleuven.be" class="auth_mail" title="E-mail the corresponding author}
• 关键词：HEV ; hepatitis E virus ; RBV ; ribavirin ; ALT ; alanine aminotransferase ; IU ; international units ; γGT ; γ-glutamyltransferase ; CLL ; chronic lymphoid leukemia ; NGS ; next-generation sequencing ; RdRp ; RNA-dependent RNA polymerase ; HVR ; hypervariable region ; ORF ; open reading frame ; IMPDH ; inosine 5&prime ; -monophosphate dehydrogenase ; MPA ; mycophenolic acid ; LOD ; limit of detection ; RLU ; relative light units ; FBS ; fetal bovine serum ; HS ; human serum ; WT ; wild-type ; VC ; virus control
• 刊名：Journal of Hepatology
• 出版年：2016
• 出版时间：September 2016
• 年：2016
• 卷：65
• 期：3
• 页码：499-508
• 全文大小：1453 K

文摘

Ribavirin monotherapy is the preferred treatment for chronic hepatitis E, although occasional treatment failure occurs. We present a patient with chronic hepatitis E experiencing ribavirin treatment failure with a completely resistant phenotype. We aimed to identify viral mutations associated with treatment failure and explore the underlying mechanisms.

Methods

Viral genomes were deep-sequenced at different time points and the role of identified mutations was assessed in vitro using mutant replicons, antiviral assays, cell culture of patient-derived virus and deep-sequencing.

Results

Ribavirin resistance was associated with Y1320H, K1383N and G1634R mutations in the viral polymerase, but also an insertion in the hypervariable region comprising a duplication and a polymerase-derived fragment. Analysis of these genome alterations in vitro revealed replication-increasing roles for Y1320H and G1634R mutations and the hypervariable region insertion. In contrast, the K1383N mutation in the polymerase F1-motif suppressed viral replication and increased the in vitro sensitivity to ribavirin, contrary to the clinical phenotype. Analysis of the replication of mutant full-length virus and in vitro culturing of patient-derived virus confirmed that sensitivity to ribavirin was retained. Finally, deep-sequencing of hepatitis E virus genomes revealed that ribavirin is mutagenic to viral replication in vitro and in vivo.

Conclusions

Mutations Y1320H, G1634R and the hypervariable region insertion compensated for K1383N-associated replication defects. The specific role of the K1383N mutation remains enigmatic, but it appears to be of importance for the ribavirin resistant phenotype in this patient.

Lay summary

Ribavirin is the most common treatment for chronic hepatitis E and is mostly effective, although some cases of ribavirin treatment failure have been described. Here, we report on a particular case of ribavirin resistance and investigate the underlying causes of treatment failure. Mutations in the viral polymerase, an essential enzyme for viral replication, appear to be responsible.