ABSTRACT
A percentage of hepatitis C virus (HCV)-infected patients fail direct acting antiviral (DAA)-based treatment regimens, often because of drug resistance-associated substitutions (RAS). The aim of this study was to characterize the resistance profile of a large cohort of patients failing DAA-based treatments, and investigate the relationship between HCV subtype and failure, as an aid to optimizing management of these patients. A new, standardized HCV-RAS testing protocol based on deep sequencing was designed and applied to 220 previously subtyped samples from patients failing DAA treatment, collected in 39 Spanish hospitals. The majority had received DAA-based interferon (IFN) α-free regimens; 79% had failed sofosbuvir-containing therapy. Genomic regions encoding the nonstructural protein (NS) 3, NS5A, and NS5B (DAA target regions) were analyzed using subtype-specific primers. Viral subtype distribution was as follows: genotype (G) 1, 62.7%; G3a, 21.4%; G4d, 12.3%; G2, 1.8%; and mixed infections 1.8%. Overall, 88.6% of patients carried at least 1 RAS, and 19% carried RAS at frequencies below 20% in the mutant spectrum. There were no differences in RAS selection between treatments with and without ribavirin. Regardless of the treatment received, each HCV subtype showed specific types of RAS. Of note, no RAS were detected in the target proteins of 18.6% of patients failing treatment, and 30.4% of patients had RAS in proteins that were not targets of the inhibitors they received. HCV patients failing DAA therapy showed a high diversity of RAS. Ribavirin use did not influence the type or number of RAS at failure. The subtype-specific pattern of RAS emergence underscores the importance of accurate HCV subtyping. The frequency of "extra-target" RAS suggests the need for RAS screening in all three DAA target regions.
Subject(s)
Antiviral Agents/therapeutic use , Drug Resistance, Multiple, Viral/genetics , Hepacivirus/drug effects , Hepacivirus/genetics , Mutation , Antiviral Agents/pharmacology , Cohort Studies , Drug Therapy, Combination , Genotype , Hepatitis C/drug therapy , High-Throughput Nucleotide Sequencing , Humans , Spain , Treatment FailureABSTRACT
FUNDAMENTO: Se ha implicado la existencia de microquimerismo fetal (MQF) en la etiopatogenia de la CBP. El objetivo de este estudio fue determinar la presencia de MQF en pacientes diagnosticadas de CBP. PACIENTES Y MÉTODO: Se estudió la presencia de MQF en 28 mujeres, 14 con CBP y 14 controles sanos. Se extrajo ADN a partir de células de sangre periférica, y mediante reacción en cadena de polimerasa se detectó una secuencia específica de cromosoma Y, que se confirmó por análisis Southern blot. RESULTADOS: Se detectó MQF en un única paciente diagnosticada de CBP (7 per cent) y en nigún caso del grupo control. CONCLUSIONES: La presencia de MQF no parece desempeñar un papel importante en la patogenia de las pacientes con CBP (AU)
Subject(s)
Middle Aged , Aged , Adult , Female , Humans , Y Chromosome , DNA , Liver Cirrhosis, Biliary , FetusABSTRACT
BACKGROUND: Fetal microchimerism (FM) has been implicated in the pathogenesis of primary biliary cirrhosis (PBC). The aim of the study was to investigate the presence of FM in PBC patients. PATIENTS AND METHOD: FM was studied in 28 women, 14 with PBC and 14 healthy controls.DNA was extracted from peripheral blood cells, and a PCR analysis to detect a specific Y-chromosome sequence was performed. Specificity was confirmed by Southern-blot analysis. RESULTS: The Y-chromosome sequence was amplified from peripheral-blood cell DNA in only one PBC patient and in none of the controls. CONCLUSIONS: FM does not seem to play a major role in patients with PBC.
