BACKGROUND Tenofovir alafenamide fumarate(TAF)is one of the first-line treatments used to treat chronic hepatitis B patients;TAF has strong antiviral activity and a high barrier to resistance.Although virological brea...BACKGROUND Tenofovir alafenamide fumarate(TAF)is one of the first-line treatments used to treat chronic hepatitis B patients;TAF has strong antiviral activity and a high barrier to resistance.Although virological breakthroughs in patients during TAF treatment are rare,patients with incomplete responses to TAF are occasionally observed.AIM To investigate responsible mutations in the reverse transcriptase region of hepatitis B virus(HBV)for TAF-incomplete responses.METHODS Thirteen chronic hepatitis B patients who received TAF monotherapy were included.A TAF-incomplete responder was defined as one who was continuously positive for HBV DNA over 2 years after TAF treatment initiation.The emergences of mutations in TAF-incomplete responders were evaluated before,one year after,and two years after treatment by deep sequencing of HBV DNA and RNA.RESULTS Two patients were continuously positive for HBV DNA over two years.The rtL269I mutation,one of the CYEI mutations linked to tenofovir resistance,was detected in both patients by direct sequencing.The deep sequencing analysis revealed that a combination of rtT118A and rtL220I mutations and the rtL269I mutation were predominantly detected in HBV DNA even when these mutations were barely detected in HBV RNA.This suggests a superior replication capability of the HBV variants with these mutations under TAF treatment.CONCLUSION The deep sequencing analysis of HBV DNA and RNA and comparing the detection rates of mutations were useful for estimating responsible mutations for TAF-incomplete responses.Such analysis is needed to evaluate the association between mutations that emerge during TAF treatment and incomplete responses to TAF.展开更多
AIM To investigate the prevalence and virological characteristics of occult hepatitis B virus(HBV)infections in patients with hematological malignancies in South Egypt.METHODS Serum samples were collected from 165 pat...AIM To investigate the prevalence and virological characteristics of occult hepatitis B virus(HBV)infections in patients with hematological malignancies in South Egypt.METHODS Serum samples were collected from 165 patients with hematological malignancies to monitor titers of HBV DNA,hepatitis B surface antigen(HBs Ag),and antibodies to HBV core(anti-HBc)and surface antigens.Serum samples negative for HBs Ag and positive for anti-HBc were subjected to nucleic acid extraction and HBV DNA detection by real-time polymerase chain reaction.DNA sequences spanning the S region were analyzed in cases with occult HBV infection.In vitro comparative study of constructed 1.24-fold wild type and S protein mutant HBV genotype D clones was further performed.RESULTS HBV DNA was detected in 23(42.6%)of 54 patients with hematological malignancies who were HBsA g negative,but anti-HBc positive,suggesting the presence of occult HBV infection.The complete HBV genome was retrieved from 6 occult HBV patients,and P120 T and S143 L were detected in 3 and 2 cases,respectively.Site directed mutagenesis was done to produce 1.24-fold genotype D clones with amino acid mutations T120 and L143.The in vitro analyses revealed that a lower level of extracellular HBsA g was detected by chemiluminescence enzyme immunoassay(CLEIA)with the clone containing T120 mutation,compared with the wild type or the clone with S143 L mutation despite the similar levels of extracellular and intracellular HBs Ag detected by Western blot.Southern blot experiments showed that the levels of intracellular HBV DNA were not different between these clones.CONCLUSION Occult HBV infection is common in patients with hematological malignancies and associated with P120 T and S143 L mutations.120 T mutation impairs the detection of HBsA g by CLEIA.展开更多
基金Supported by the Japan Agency for Medical Research and Development(AMED),No.JP22fk0310503.
文摘BACKGROUND Tenofovir alafenamide fumarate(TAF)is one of the first-line treatments used to treat chronic hepatitis B patients;TAF has strong antiviral activity and a high barrier to resistance.Although virological breakthroughs in patients during TAF treatment are rare,patients with incomplete responses to TAF are occasionally observed.AIM To investigate responsible mutations in the reverse transcriptase region of hepatitis B virus(HBV)for TAF-incomplete responses.METHODS Thirteen chronic hepatitis B patients who received TAF monotherapy were included.A TAF-incomplete responder was defined as one who was continuously positive for HBV DNA over 2 years after TAF treatment initiation.The emergences of mutations in TAF-incomplete responders were evaluated before,one year after,and two years after treatment by deep sequencing of HBV DNA and RNA.RESULTS Two patients were continuously positive for HBV DNA over two years.The rtL269I mutation,one of the CYEI mutations linked to tenofovir resistance,was detected in both patients by direct sequencing.The deep sequencing analysis revealed that a combination of rtT118A and rtL220I mutations and the rtL269I mutation were predominantly detected in HBV DNA even when these mutations were barely detected in HBV RNA.This suggests a superior replication capability of the HBV variants with these mutations under TAF treatment.CONCLUSION The deep sequencing analysis of HBV DNA and RNA and comparing the detection rates of mutations were useful for estimating responsible mutations for TAF-incomplete responses.Such analysis is needed to evaluate the association between mutations that emerge during TAF treatment and incomplete responses to TAF.
基金Supported by Japan Society for the Promotion of Science,No.15H05289
文摘AIM To investigate the prevalence and virological characteristics of occult hepatitis B virus(HBV)infections in patients with hematological malignancies in South Egypt.METHODS Serum samples were collected from 165 patients with hematological malignancies to monitor titers of HBV DNA,hepatitis B surface antigen(HBs Ag),and antibodies to HBV core(anti-HBc)and surface antigens.Serum samples negative for HBs Ag and positive for anti-HBc were subjected to nucleic acid extraction and HBV DNA detection by real-time polymerase chain reaction.DNA sequences spanning the S region were analyzed in cases with occult HBV infection.In vitro comparative study of constructed 1.24-fold wild type and S protein mutant HBV genotype D clones was further performed.RESULTS HBV DNA was detected in 23(42.6%)of 54 patients with hematological malignancies who were HBsA g negative,but anti-HBc positive,suggesting the presence of occult HBV infection.The complete HBV genome was retrieved from 6 occult HBV patients,and P120 T and S143 L were detected in 3 and 2 cases,respectively.Site directed mutagenesis was done to produce 1.24-fold genotype D clones with amino acid mutations T120 and L143.The in vitro analyses revealed that a lower level of extracellular HBsA g was detected by chemiluminescence enzyme immunoassay(CLEIA)with the clone containing T120 mutation,compared with the wild type or the clone with S143 L mutation despite the similar levels of extracellular and intracellular HBs Ag detected by Western blot.Southern blot experiments showed that the levels of intracellular HBV DNA were not different between these clones.CONCLUSION Occult HBV infection is common in patients with hematological malignancies and associated with P120 T and S143 L mutations.120 T mutation impairs the detection of HBsA g by CLEIA.
