Genotypic and phenotypic resistance: longitudinal and sequential analysis of hepatitis B virus polymerase mutations in patients with lamivudine resistance after liver transplantation

Risk factors for hepatitis B virus recurrence after living donor liver transplantation: A 22-year experience at a single center

The factors associated with hepatitis B virus (HBV) recurrence after living donor liver transplantation (LDLT) have not been fully clarified. The aim of this study was to determine the risk factors associated with HBV recurrence after LDLT. From January 1996 to December 2018, a total of 609 LDLT operations were performed at our center. A retrospective review was performed of 70 patients (male, n = 59; female, n = 11; median age = 54 years) who underwent LDLT for HBV-related liver disease. The virologic and biochemical data, tumor burden, antiviral and immunosuppressive therapy were evaluated and compared between the HBV recurrence and non-recurrence groups. Eleven of 70 patients (16%) developed post-LDLT HBV recurrence. The overall actuarial rates of HBV recurrence at 1, 3, 5, 10, and 20 years were 0%, 13%, 16.7%, 18.8%, and 18.8%, respectively. The median interval between LDLT and HBV recurrence was 57 months (range, 18-124 months). Based on the univariate and multivariate analyses, a serum HBV DNA level of ≥ 4 log copies/mL (hazard ratio [HR], 4.861; 95% confidence interval [95% CI], 1.172-20.165; P = 0.029), and hepatocellular carcinoma (HCC) beyond the Milan criteria (HR, 10.083; 95% CI, 2.749-36.982; P < 0.001) were independent risk factors for HBV recurrence after LDLT. In LDLT patients, high pre-LT HBV DNA levels and HCC beyond the Milan criteria were risk factors for HBV recurrence. With the current expansion of the LT criteria for HCC, we should remain cautious regarding the risk of HBV recurrence, particularly in these groups.

The efficiency of low-dose hepatitis B immunoglobulin plus nucleos(t)ide analogs in preventing posttransplant hepatitis B virus recurrence

Background/aim

In this study, the efficiency of using low-dose hepatitis B immunoglobulin (HBIG) plus antiviral treatment according to individual needs has been evaluated in posttransplant hepatitis B virus (HBV) patients.

Materials and methods

We retrospectively evaluated 179 patients who were admitted between 2009 and 2014. Five thousand IU intravenous HBIG was given in the anhepatic phase, and 400 IU/day intramuscular (IM) HBIG was given in the posttransplant period. After HBsAg seroconversion, 400 IU IM HBIG was continued as prophylaxis every two weeks.

Results

The average follow-up period was 26 (2–65) months. Seventy patients had hepatocellular carcinoma (HCC). The HBV recurrence was 4.5% in the first year, and 5.8% in the third year. The HBsAg became negative in 11 (2–63) days, and anti-HBs became positive in 9 (1–31) days. HBsAg positivity occurred in 6 patients during the follow-up period. Five of these patients were those who underwent transplantation due to HCC. In 5 of the HCC patients, in whom HBsAg became positive, tumor recurrence was observed after 0.3–9.9 months. HBsAg positivity was more frequently detected in patients with HCC (P = 0.009).

Conclusion

The HBV recurrence should be evaluated as a predictor of the HCC recurrence in patients who were transplanted due to HCC.

High-dose hepatitis B immunoglobulin therapy in hepatocellular carcinoma with hepatitis B virus-DNA/hepatitis B e antigen-positive patients after living donor liver transplantation

AIM: To investigate the impact of high-dose hepatitis B immunoglobulin (HBIG) on hepatocellular carcinoma (HCC) and hepatitis B virus (HBV) recurrence and overall survival after living donor liver transplantation (LDLT).

METHODS: We investigated 168 patients who underwent LDLT due to HCC, and who were HBV-DNA/hepatitis B e antigen (HBeAg) -positive, from January 2008 to December 2013. After assessing whether the patients met the Milan criteria, they were assigned to the low-dose HBIG group and high-dose HBIG group. Using the propensity score 1:1 matching method, 38 and 18 pairs were defined as adhering to and not adhering to the Milan criteria. For each pair, HCC recurrence, HBV recurrence and overall survival were analyzed by the Kaplan-Meier method and the log rank test according to the HBIG dose.

RESULTS: Among those who met the Milan criteria, the 6-mo, 1-year, and 3-year HCC recurrence-free survival rates were 88.9%, 83.2%, and 83.2% in the low-dose HBIG group and 97.2%, 97.2%, and 97.2% in the high-dose HBIG group, respectively (P = 0.042). In contrast, among those who did not meet the Milan criteria, HCC recurrence did not differ according to the HBIG dose (P = 0.937). Moreover, HBV recurrence and overall survival did not differ according to the HBIG dose among those who met (P = 0.317 and 0.190, respectively) and did not meet (P = 0.350 and 0.987, respectively) the Milan criteria.

CONCLUSION: High-dose HBIG therapy can reduce HCC recurrence in HBV-DNA/HBeAg-positive patients after LDLT.

Risk factors for hepatitis B virus recurrence after living donor liver transplantation: A 17-year experience at a single center

AIM

The incidence of hepatitis B virus (HBV) recurrence after liver transplantation (LT) has been reduced by prophylaxis with hepatitis B immunoglobulin (HBIG) and nucleoside analogs, but the factors associated with HBV recurrence are unclear. The aim of this study was to determine the risk factors associated with HBV recurrence after living donor LT (LDLT).

METHODS

A retrospective review was performed for 45 patients (28 male and 17 female; median age, 54 years) who underwent LDLT for HBV-related liver disease and were followed up for at least 6 months between October 1996 and June 2013. The virological data, tumor burden, antiviral therapy and immunosuppressive therapy were evaluated and compared between the HBV recurrence ad non-recurrence groups.

RESULTS

Seven of the 45 patients (15.6%) developed post-LT HBV recurrence. The median interval between LDLT and HBV recurrence was 23.7 months (range, 0.8-35.9). Three of the seven patients (42.9%) developed recurrence after cessation of HBIG, and three (42.9%) were cases with hepatocellular carcinoma (HCC) recurrence after LDLT. The remaining case underwent transplantation from a donor with positive hepatitis B surface antigen. Based on the univariate and multivariate analyses, HBIG cessation (hazard ratio [HR], 20.17; 95% confidence interval [95% CI], 2.091-194.593; P = 0.009) and HCC recurrence (HR, 30.835; 95% CI, 3.132-303.593; P = 0.003) were independent risk factors for HBV recurrence after LDLT.

CONCLUSION

In LDLT patients, cessation of HBIG and HCC recurrence were risk factors associated with HBV recurrence, so careful monitoring for serological HBV markers is needed in patients with these factors.

Variations in the S and P regions of the hepatitis B virus genome under immunosuppression in vitro and in vivo

To provide a basis for improved prevention and treatment of hepatitis B virus (HBV) re-infection after liver transplantation, variations in the S and P genes of HBV under immunosuppression in vitro and their association with patient prognosis were investigated. For the in vitro study, HepG2.2.15 hepatocellular carcinoma cells stably producing HBV particles were treated with the immunosuppressants methylprednisolone (MP) and tacrolimus (FK506) at doses found to be non-toxic by the methylthiazolyl tetrazolium (MTT) cell viability assay. MP dose-dependently inhibited HBV DNA expression in HepG2.2.15 cells, while FK506 did not, as determined by quantitative real-time PCR (qRT-PCR). By gene sequencing, both MP and FK506 were found to cause variations in HBV S, P, and S/P overlapping regions. MP- but not FK506-induced mutations were common in the glucocorticoid response element of the P region, while both immunosuppressants caused mutations outside the nucleoside analogue resistance sites. For the in vivo study, 14 patients with HBV-related end-stage liver disease re-infected after liver transplantation, and 20 cases without HBV re-infection as controls, were studied. Seventy-five percent of re-infected recipients showed multi-loci amino acid mutations at different sites besides lamivudine (LAM)-resistant loci in the P region, including in the glucocorticoid response element. Fifty percent of re-infected recipients had mutations in the "a" determinant region and flanking sequences. Re-infection was associated with negative serum hepatitis B immunoglobulin (HBIG), as measured by a microparticle capture enzyme immunoassay. Nucleotide mutations in the S region caused missense or synonymous mutations, which caused synonymous mutations in the overlapping P region. These results showed that effects of immunosuppressants on HBV genes in vitro were different from those in clinical recipients. Positive HBV DNA and gene mutations pre-transplantation were factors affecting re-infection post-transplantation. Multiple mutations found in the P and S genes suggest that the formation of quasispecies contributes to HBV re-infection after liver transplantation.

Geographical and genetic diversity of the human hepatitis B virus

Hepatitis B virus (HBV) is one of the most widely distributed viruses that infect humankind. Distinct clinical and virological characteristics of the HBV-infection have been reported in different geographical parts of the world and are increasingly associated with genetic diversity of the infecting virus. HBV is classified into genotypes and subgenotypes that are associated with ethnicity and geography. The genetic diversity of HBV in its various aspects has been the subject of extensive investigations during the last few decades. Since molecular epidemiology research tools have become widely available, the number of new publications in this field has grown exponentially. This review summarises the recent publications on the geographical distribution of genetic variants of HBV, and proposes updated criteria for the identification of new genotypes and subgenotypes of the virus.

Recurrence of hepatocellular carcinoma and hepatitis B reinfection in hepatitis B surface antigen-positive patients after liver transplantation

Hepatitis B virus (HBV) reinfection and recurrence of hepatocellular carcinoma (HCC) after orthotopic liver transplantation (OLT) are associated with increased graft failure and reduced patient survival. We evaluated the effects of both HCC recurrence and HBV reinfection on the long-term survival of these patients after OLT. One hundred seventy-five patients underwent OLT for HBV-related liver diseases and were the subjects of this retrospective study. We assessed risk factors for HBV reinfection, HCC recurrence, and survival post-OLT using univariate and multivariate analyses. During a mean follow-up of 43.0 +/- 42.0 months, 88 of 175 (50.3%) patients transplanted for HBV-related liver disease had HCC prior to OLT. Thirteen (14.8%) of these patients had HCC recurrence after OLT. The mean time for recurrence of HCC was 26.1 +/- 31.9 months. Twelve of 175 (6.9%) patients developed HBV reinfection after liver transplantation. The mean time for HBV reinfection was 28.7 +/- 26.4 months. Ten of these 12 (83.3%) patients had HCC prior to OLT, and 5 (50%) developed recurrence of HCC. On multivariate analyses, pre-OLT HCC and recurrence of HCC post-OLT were significantly associated with HBV reinfection after transplantation (P = 0.031 and P < 0.001, respectively). HCC recurrence after OLT was associated with lymphovascular invasion (P < 0.001) and post-OLT chemotherapy (P < or = 0.001). The 3- and 5-year survival rates were significantly decreased in patients with HBV reinfection (P = 0.007) and in patients with HCC recurrence after OLT (P = 0.03). In conclusion, pre-OLT HCC and HCC recurrence after transplantation were associated with HBV reinfection and with decreased patient survival. Hepatitis B immunoglobulin and antiviral therapy was only partially effective in preventing HBV reinfection in patients with HCC recurrence.

Lamivudine resistance and other mutations in the polymerase and surface antigen genes of hepatitis B virus associated with a fatal hepatic failure case

BACKGROUND AND AIM

Resistance to lamivudine therapy of chronic hepatitis B virus (HBV) infection occurs by mutation in the YMDD motif of the reverse transcriptase (rt) domain (rtM204V/I) of the virus polymerase, and is usually accompanied by rtL180M mutation. Here we investigated virological factors associated with hepatic failure in a 58-year-old male, chronically HBV-infected patient who died after 33 months of lamivudine therapy.

METHODS

Nucleotide sequencing was performed from one sample collected before and two samples collected during lamivudine therapy.

RESULTS

A peak of alanine aminotransferase and aspartate aminotransferase levels occurred after 19 months of lamivudine treatment, associated with the rtM204I mutation. After 32 months, the rtM204V mutation was predominant, accompanied by the lamivudine-resistant rtL180M mutation. Furthermore, two rare polymerase (rtS117Y and rtV142A) and three HBsAg (L109I, F134L, and I208T) substitutions were observed. At that time, the patient was hospitalized with hepatic decompensation, followed by hepatic failure, and died one month later. HBV-DNA was detected at moderate levels (8.3 x 10(4)-2.6 x 10(6) copies/mL) throughout.

CONCLUSION

The results suggest that substitutions in polymerase (rtS117Y, rtV142A) and surface antigens (L109I, F134L, and I208T), associated with lamivudine-resistant mutations at positions 180 and 204, were involved in this case of fatal hepatitis B.

Differences of YMDD mutational patterns, precore/core promoter mutations, serum HBV DNA levels in lamivudine-resistant hepatitis B genotypes B and C

The aims of this study were to investigate the viral differences among lamivudine-resistant hepatitis B virus (HBV) genotypes B and C in vivo. Fifty-three patients carrying lamivudine-resistant HBV were enrolled in this study. HBV genotypes, Levels of alanine aminotransferase (ALT), HBV DNA levels were monitored during therapy. The polymerase and precore/core promoter genes were amplified by polymerase chain reaction and their products were sequenced directly. Among 53 patients resistant HBV genotypes B and C accounted for 41.50% and 58.50%, respectively. The occurrence of reverse transcriptase rt204I mutants was lower in genotype B (36.36%) than that in genotype C (87.10%), whereas rt204V mutants was higher in genotype B (63.64%) than that in genotype C (12.90%). The occurrence of precore mutation (nt1896A) was higher in genotype B (77.27%) than that in genotype C (32.26%). Serum HBV DNA levels after emergence of lamivudine resistance were higher in genotype C (7.71 +/- 0.80 Log copies/mL) compared with genotype B (6.97 +/- 0.77 Log copies/mL). Multivariate analysis identified pretreatment HBV DNA levels, HBeAg status and HBV genotype as independent factors associated with a shorter time to lamivudine resistance(P = 0.035, P = 0.006 and P = 0.001, respectively). Multivariate analysis showed that HBV genotype (P = 0.004) and pretreatment ALT levels (P = 0.01) was independently associated with YMDD mutational patterns. The results showed that the YMDD mutational patterns, precore mutation and serum HBV DNA levels differ between lamivudine-resistant HBV genotypes B and C in vivo. It is valuable for treatment of lamivudine-resistant HBV in clinic.

Discontinuation of lamivudine treatment for hepatitis flare after kidney or heart transplantation in hepatitis B surface antigen-positive patients: A retrospective case series

BACKGROUND

Limited data are available on the clinical course of hepatitis B virus (HBV) infection after discontinuation of lamivudine prescribed for kidney or heart posttransplantation hepatitis flare

OBJECTIVE

The purpose of this study was to investigate the reasons for discontinuation, subsequent reappearance of HBV DNA, and mortality in heart and kidney transplant recipients who discontinued lamivudine treatment.

METHODS

This retrospective case series followed up male and female hepatitis B surface antigen (HBsAg)-positive Taiwanese transplant recipients from the National Taiwan University Hospital, Taipei, Taiwan, between July 1989 and January 1999. Biochemical, virologic, and serologic parameters and liver-related mortality of patients who discontinued lamivudine 100 mg QD prescribed for posttransplantation hepatitis flare were compared with those in a group of patients who continued use of lamivudine administered for the same indication over the same period of time. Serum HBV DNA levels were checked in all patients before and after discontinuation of lamivudine, and after resumption of lamivudine treatment and in patients with breakthrough hepatitis flare.

RESULTS

A total of 39 HBsAg-positive transplant recipients (mean [SD] age, 45 [10.0] years) were identified during regular follow-up visits. Nine patients discontinued lamivudine use; 11 patients who continued it were selected as a control group. No significant between-group differences were observed in mean (SD) age (46 [14.0] vs 45 [6.9] years), sex (men/women,vs 1), type of transplant received (heart/kidney,vs ), or pretransplantation liver function test results. The reasons for discontinuation were informed patient decision (4 patients); YMDD mutation (2); self-discontinuation without physician consultation (2); and pregnancy (1). Of those who discontinued lamivudine, serum HBV DNA was undetectable at a mean of 30 (range, 9-47) months' follow-up in 6 (66.7%) of 9 patients. Lamivudine treatment was resumed in 3 patients on reappearance of HBV DNA, and a subsequent rapid decline in the serum HBV DNA was observed. The liver-related mortality rate was not significantly higher in patients who discontinued treatment compared with continuously treated patients (both, 0%). The between-group difference in overall mortality rates was not significant (22.2% and 18.2%, respectively).

CONCLUSIONS

This case series illustrated a variety of clinical situations in which discontinuation of lamivudine treatment prescribed for posttransplantation hepatitis flare may occur. However, liver-related mortality was not increased in these patients compared with those who continued lamivudine treatment.

Low-dose intra-muscular hepatitis B immunoglobulin combined with lamivudine for long-term prophylaxis of hepatitis B recurrence after liver transplantation

AIM: To evaluate the efficacy of long-term, low-dose intra-muscular hepatitis B immunoglobulin (HBIg) combined with lamivudine (LAM) in patients who received orthotopic liver transpl-ants (OLT) and have been followed up for acute or chronic HBV-related end-stage liver disease.

METHODS: The liver transplantation recipients (n = 173) who have been followed up and received antiviral prophylaxis post-OLT were divided into 3 sub-groups according to their post-OLT antiviral therapy, which were group A (LAM monotherapy, n = 2), group B (HBIg and LAM therapy, n = 168) and group C (HBIg and ADF therapy n = 3). All the patients received LAM treatment for 1 or 2 wk ahead of OLT. Either LAM (100 mg) or ADF (adefovir dipivoxil, 10 mg) was administered orally every day. HBIg were administered intravenously during the first post-operative week (total 5000 or 10 000 U according to HBV copies/L pre-operative) and intramuscularly thereafter (400 U per time, the interval can be adjusted according to HBsAb titer in the blood) to maintain an HBsAb titer > 300 U/L within 1 mo, > 200 U/L between 2-3 mo and > 100 U/L beyond 3 mo after operation. Mean follow-up period was 20.8 ± 14 mo. The periodical investigation for the liver function, the serological HBV and the analyses of liver tissues by immunohistochemistry were performed. The recurrent HB and the death suffered from it were recorded and analyzed in this research. The recurrence rates of HBV infection between UCLA and our institute were statistically analyzed.

RESULTS: Four patients experienced HBV recurrence overall. One patient in group A experienced HBV recurrence (1 week after OLT) and positive HBV DNA (2 mo after OLT) associated with an increase in serum alanine aminotransferase. The treatment resistance of LAM was defined and the recipient died of the multiple organ failure 8 mo after OLT. Recurrent HBV appeared in 3 patients, whose HBV DNA levels in the pre-OLT blood were more than 10⁸ copies/L, in group B (12 d, 12 mo and 1.5 mo after OLT respectively). The pre- and post-operative HBeAg and HBV DNA were always positive in the first case whose blood HBsAb titer was far lower than programming effective one. The treatment resistance of HBIg was defined and the patient died of fulminant hepatitis 11 mo after OLT. The second case became an HBsAg carrier after HBV recurrence and was dead due to tumor recurrence 15 mo after OLT. The third case was fine with the treatment of HBIg combined with ADF and was negative for HBsAg after 5.5 mo. The HBV mutation might exist in both of the second and third case. None of group C had HBV recurrence. The HBV recurrence rate under the prophylaxis of HBIg combined with LAM was 1.8% (3/168). Intra-muscular HBIg was tolerated well in all the cases. The study showed no difference between UCLA and our institute (χ² = 0.280 37), and the expenditure was 3000-4000 US dollars per year.

CONCLUSION: The low-dose intra-muscular HBIg combined with LAM is efficacious in the long-term prophylaxis of hepatitis B recurrence after OLT. The total expenditure of prophylaxis is lower. ADF shows efficacy against the HBV-YMDD lamivudine-resistant mutation and may be a more efficacious agent for the prophylaxis of HBV recurrence after OLT.

Current treatment and future directions in the management of chronic hepatitis B viral infection

The World Health Organization places hepatitis B virus (HBV) in the top 10 causes of death worldwide. It is estimated that there are over 400 million carriers of HBV as well. At least 20% to 30% of hepatitis B surface antigen (HBsAg) carriers will die of complications of chronic liver disease, including cirrhosis and liver cancer. The serious consequences of end-stage liver disease and liver cancer occur in 30% of chronic carriers and confront patients and physicians throughout the world. Vaccination is the major form of treatment (prevention) that may eventually eliminate HBV worldwide. This article discusses the currently available treatments as well as evolving treatments for chronic HBV infection.

Polymerase Domain B Mutation Is Associated with Hepatitis Relapse during Long-Term Lamivudine Therapy for Chronic Hepatitis B

Breakthrough hepatitis remains the major issue in long-term lamivudine therapy for chronic hepatitis B. However, the emergence of drug-resistant hepatitis B virus (HBV) is not always accompanied by a relapse of hepatitis. To elucidate factors predictive of breakthrough hepatitis, 53 patients with genotype C of HBV on long-term lamivudine therapy were analyzed. HBV reappeared during therapy in 19 patients with a cumulative incidence of 15% at 1 year, 34% at 2 years, and 60% at 3 years. Within this group, breakthrough hepatitis developed in 12 patients (63%). A polymerase gene domain B mutation (rt180M) emerged in 13 patients, and domain C mutations (rt204I, rt204V) were found in 19 patients. The rt180M mutation was associated with breakthrough hepatitis (p < 0.05) with a positive predictive value of 85% and a negative predictive value of 83%. Patients with the rt180M mutation had higher HBV-DNA levels during viral breakthrough compared to patients with rt180wt (p < 0.05). The mutational pattern of rt204 was not associated with breakthrough hepatitis. In conclusion, genotypic assays for the rt180M mutation after viral breakthrough may be useful in predicting the risk of breakthrough hepatitis and in deciding when to initiate alternative or additive nucleoside analogue therapy.

YMDD variants of HBV DNA polymerase gene: Rapid detection and clinicopathological analysis with long-term lamivudine therapy after liver transplantation

AIM: To look for a rapid low-cost technique for the detection of HBV variants.

METHODS: Two patients who underwent orthotopic liver transplantation (OLT) for HBV infection were treated with lamivudine (100 mg daily) and HBV infection recurred in the grafted livers. The patients were monitored intensively for liver enzymes, hepatitis B surface antigen (HBsAg) and HBV DNA in serum. Liver biopsy was performed regularly. HBV DNA in a conserved polymerase domain (the YMDD locus) was amplified from serum of each patient by PCR and sequenced. HBV genotypes were analyzed by restriction fragment length polymorphism (RFLP) of the PCR products generated from a fragment of the polymerase gene.

RESULTS: YMDD wild-type HBV was detected in one patient by PCR-RFLP and DNA sequencing 19 mo after OLT, and YIDD mutant-type HBV in the other patient, 16 mo after OLT.

CONCLUSION: PCR-RFLP assay is an accurate and simple method for genotyping lamivudine-resistant HBV variants.

Prevention of hepatitis B virus reinfection after orthotopic liver transplantation

OBJECTIVE

We discuss the prevention of hepatitis B virus reinfection following orthotopic liver transplantation.

METHODS

Sixty-eight cases of chronic fulminant hepatitis B, the end stage of liver cirrhosis and liver carcinoma complicated with HBV cirrhosis, were given antiviral drugs pre- and posttransplantation to prevent hepatitis B virus reinfection. Lamivudine was administered to two cases and lamivudine + HBIG to 63 cases. Adefovir + HBIG was administered to three cases. The serum HBV, HBV DNA, liver biopsy immunohistochemistry and clinical examinations were performed.

RESULTS

One of two cases given lamivudine developed reinfection with serum HBSAg, HbeAb, HBcAb, HBV DNA, and positive and liver biopsy immunohistochemistry showing HBSAg phenotype. Two of the 63 cases given lamivudine + HBIG developed reinfection with serum HBSAg, HBeAb, HBcAb positive and liver biopsy immunohistochemistry showing HBSAg phenotype. The serum HBV DNA was positive in one of the two cases. Three cases given adefovir developed no reinfection with HBV.

CONCLUSION

Orthotopic liver transplantation is an effective treatment for HBV infection; lamivudine + HBIG or adefovir + HBIG prevent hepatitis B virus reinfection.

Prophylaxis of hepatitis B virus recurrence after liver transplantation in carriers of lamivudine-resistant mutants

The combination of lamivudine and hepatitis B immunoglobulin (HBIG) reduces the risk of hepatitis B virus (HBV) recurrence after liver transplantation (LT). However, the efficacy of this strategy and the need for combined therapy with adefovir dipivoxil (ADV) in patients who select lamivudine-resistant strains (YMDD) before surgery is still unknown. Twenty-two patients treated with lamivudine (LAM) who underwent LT after YMDD-mutant selection were studied. In 13 patients, YMDD mutants were associated with an HBV DNA breakthrough greater than 5 log10 (group A: phenotypic resistance), and 11 were treated with ADV to decrease viral load before LT. In the remaining 9 patients who did not experience the viral breakthrough, YMDD mutants were detected only retrospectively in sera stored at the time of LT (group B: genotypic resistance). During 35 months of post-LT follow-up, none of the 11 patients of group A treated with ADV before and after surgery (in addition to HBIG and LAM) had HBV recurrence, and neither did any of the 7 subjects of group B treated with LAM before and after transplantation (in addition to HBIG). HBV recurred in 2 patients of group A (untreated with ADV before surgery and transplanted with an HBV DNA exceeding 5 log10) and in 2 subjects of group B (who spontaneously stopped HBIG after surgery). In carriers of YMDD mutants, the risk of post-LT HBV recurrence is low, provided that preemptive and prophylactic ADV (in addition to LAM and HBIG) treatment is used in highly viremic patients and prophylactic LAM (or ADV) and HBIG therapy is continued in low viremic patients.

YMDD mutations in patients with chronic hepatitis B untreated with antiviral medicines

AIM: To polymerase P region (YMDD) mutations of hepatitis B virus gene (HBV DNA) in patients with chronic hepatitis B (CHB) untreated with antiviral medicines and to explore its correlation with pre-c-zone mutations, HBV genotypes and HBV DNA level, and to observe its curative effect.

METHODS: A total of 104 cases (38 cases in group of familial aggregation and 66 cases in group of non-familial aggregation) were randomly chosen from 226 patients with CHB who did not receive the treatment of lamivudine (LAM) and any other antivirus drugs within the last one year. Their serum YMDD mutations were detected by microcosmic nucleic acid and cross-nucleic acid quantitative determination, HBV genotypes by PCR-microcosmic nucleic acid cross-ELISA, HBV DNA quantitative determination and fluorescence ration PCR analysis, hepatitis B virus markers (HBVM) by ELISA. LAM was taken by 10 patients with YMDD mutations and its curative effect was observed.

RESULTS: Twenty-eight cases (26.9%) had YMDD mutations, of them 11 cases (28.9%) were in familial aggregation group (38 cases) and 17 cases (25.8%) in non-familial aggregation group (66 cases) with no significant difference between the two groups. Twenty-seven point one percent (16/59) cases were positive for HBeAg YMDD mutations, and 26.7% (12/45) cases were negative for HBeAg and positive for anti-HBe. There was also no significant difference between the two groups. Different YMDD incidence rate existed in different HBV genotypes. HBV DNA level did not have a positive correlation with the incidence of YMDD mutations. LAM was effective for all patients with mutations.

CONCLUSION: Wild mutant strains in HBV and their incidence rate have no significant difference between familial aggregation and non-familial aggregation. It may have no significant relationship between YMDD mutations and pre-c-zone mutations. HBV DNA level may not have a positive correlation with YMDD mutations. LAM is clinically effective for CHB patients with YMDD mutations.

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Prospective study on lamivudine-resistant hepatitis B in renal allograft recipients

The natural history of lamivudine-resistant hepatitis B virus (HBV) infection in renal transplant recipients (RTx) is unclear, despite its increasing incidence. Twenty-nine HBsAg-positive RTx with rising HBV DNA received lamivudine therapy. The course of lamivudine-resistant HBV infection was studied prospectively. During 68.7 +/- 12.5 months of follow-up, 14 (48.3%) patients developed lamivudine resistance, at 10-35 months (mean 16.9 +/- 7.0). All showed mutant sequences at codons 552 and 528 of the YMDD motif, while 13 patients demonstrated wild-type sequence at codon 555. Lamivudine resistance was unrelated to patient demographics, HBeAg status/sero-conversion, or genotype. Following resistance, HBV DNA and alanine aminotransferase showed an initial increase followed by spontaneous gradual reduction. The subsequent peak HBV DNA was lower (1.26 +/- 1.09 x 10(9) vs. 6.26 +/- 12.23 x 10(9) copies/mL, p = 0.011), while that of alanine aminotransferase was higher (196 +/- 117 vs. 77 +/- 47 imicro/l, p = 0.005), compared with pretreatment levels. Post-resistance hepatitic flare occurred in 11 (78.6%) patients. This was transient in four (36.4%), but became chronic in six (54.5%) patients. Decompensation was noted in one patient during this flare, but all survived. We conclude that drug resistance is prevalent in lamivudine-treated RTx. Despite a lower ensuing peak viremia compared with baseline, hepatitic flare is common. While most patients have spontaneous resolution, a minority may develop potentially fatal decompensation during the preceding exacerbation.

Two subtypes of genotype B (Ba and Bj) of hepatitis B virus in Japan

We have previously reported 2 subtypes of hepatitis B virus (HBV) genotype B, one of which has the recombination with genotype C over the precore region plus core gene (Ba) and the other of which does not (Bj). A restriction fragment-length polymorphism method with 2 endonucleases was newly developed for distinguishing between subtypes Ba and Bj and was applied to 313 carriers of HBV genotype B in Japan. Subtype Ba was detected in 38 (12%) and subtype Bj in 275 (88%) of the carriers of HBV genotype B. Hepatitis B e antigen in serum was found more frequently in patients with chronic infection with subtype Ba than in those with chronic infection with subtype Bj (8 [32%] of 25 vs. 25 [9%] of 273; P<.01). The new method for distinguishing between Ba and Bj by restriction fragment-length polymorphism would be useful in examining the distribution of these 2 subtypes in situations in which HBV genotype B is prevalent.

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