YMDD Mutants Research Articles

The study of the relationship between YMDD mutation and the degree of liver function destroyed

目的 采用自行研制的微量核酸释放剂(micro-nucleic acid releasing reagent, MNRR),建立微量血清直接进行PCR扩增的一步法实时荧光PCR检测拉米夫定治疗后YMDD变异的情况,探讨乙肝病毒YMDD变异与肝脏功能损伤程度的关系.方法设计包含YIDD和YVDD变异区和无变异参照的三条下游引物,与同一上游引物和探针建立3管荧光PCR扩增体系,变异Ct值与参照Ct值之差在3.3之内判断为阳性变异.建立将血清标本直接加到含有MNRR的扩增管进行核酸处理和PCR扩增的一步法检测.将0.2 ml 的PCR扩增管按3管/份标本排放到核酸提取仪,每管加入3.5 μl 的MNRR和3.5μl待测血清,用带虑芯吸头的加样器轻轻吹打混匀,加30 μl无菌石蜡油覆盖,于80℃静置8 min和10℃静置1 min,直接加入PCR扩增液,封盖后移至实时荧光PCR仪进行扩增.对154例采用拉米夫定治疗1年后的乙肝患者YIDD变异发生率进行分析,并研究其与肝脏功能损伤程度之间的关系.结果拉米夫定治疗1年后YIDD变异率为15.9%;YVDD变异率为9.6%,YIDD和YVDD共生变异率为4.4%.发生YIDD/YVDD共生变异的患者其血清HBV DNA 含量显著高于单一发生YIDD变异的患者(P<0.05),发生YMDD共生变异的乙肝患者其肝脏功能损伤的程度明显较单一发生YIDD变异者严重.结论拉米夫定治疗发生共生变异的患者其血清HBV DNA含量显著高于单一发生YIDD或YVDD变异的患者;发生YMDD共生变异的乙肝患者其肝功能损伤的程度明显重于无变异或单一发生YMDD变异的患者。

The development and reliability study of high throughput assay for YMDD mutation by pyrosequencing

目的 建立基于焦磷酸测序技术的高通量的乙型肝炎病毒YMDD突变临床检测方法.方法应用专用的YMDD突变区域的扩增引物,经PCR扩增及磁珠分离,制备YMDD区焦磷酸测序单链模板,并在PSQ96A焦磷酸测序仪上进行焦磷酸测序,应用标准的YMDD区突变质粒作为阳性对照模板和标准品,观察批量分析的可靠性并初步批量检定90例临床血清标本.结果建立了基于焦磷酸测序技术的YMDD突变检测平台,实现了临床血清标本的高通量检测.能一次获得90人份的YMDD突变临床检测结果.经标准的YMDD突变质粒及血清标本的重复性及可靠性检测,质粒标准品的突变检出率及重复率均达100%,而血清标本达98.8%.结论本方法可准确.高通量、快速检测YMDD区突变,特别适宜临床批量检测需要。

Adefovir dipivoxil in treatment of decompensated liver cirrhosis patients with YMDD mutation

To evaluate the efficacy and safety of adefovir dipivoxil in treatment of decompensated liver cirrhosis patients with YMDD motif mutation during lamivudine therapy. The disease relapsed in 14 hepatitis B patients with decompensated liver cirrhosis during lamivudine treatment due to the YMDD motif mutation. All 14 patients had positive HVBDNA and active hepatitis, and were evaluated as Child-Pugh Score C (CPS-C). The patients were treated with lamivudine 50 mg/d and adefovir dipivoxil 10 mg/d for 6 months. One patient signed off due to non-hypoxemic hyperlactacidemia; other 13 patients showed decreased serum HBVDNA. All patients had serum HBVDNA < or =10(5) copies/ml and 7 patients had HBVDNA < or =10(4) copies/ml. Six patients regained normal serum ALT level and Child-Pugh scores decreased in all patients. Adefovir dipivoxil has satisfied efficacy and safety in treatment of decompensated liver cirrhosis patients with YMDD motif mutation during lamivudine treatment.

Use of Hepatitis B Core Antibody–Positive Liver Allograft in Hepatitis C Virus–Positive and –Negative Recipients With Use of Short Course of Hepatitis B Immunoglobulin and Lamivudine

Introduction With the shortage of donor organs, increasing number of hepatitis B core antibody (HBcAb)–positive [HBcAb(+)] liver allografts are being used for liver transplantation (LTx) in patients who are HBcab-negative [HBsAb(−)]. This study was aimed at assessing outcomes for hepatitis C virus (HCV)-positive [HCV(+)] and HCV-negative [HCV(−)] patients who received HBcAb(+) liver grafts from deceased donors and also received a short course of hepatitis B immunoglobulin (HBIg) with long-term lamivudine therapy after LTx. Materials and methods From February 1995 through February 2003, 28 patients (mean age 53.8 ± 10.2 years, 19 men and nine women, 16 HCV[−]; 12 HCV[+]) received HbcAb(+) liver allografts. All recipients received a short course of HBIg prophylaxis (10,000 units/day for 4 days) and long-term lamivudine 100 mg/d after LTx in addition to a tacrolimus-based immunosuppressive regimen. Results Seven (25%) of the 28 recipients died during follow-up and three recipients required retransplantation. Three recipients (10.7%) developed HBV infection during follow-up, one of whom died 36 months after LTx and the other two had YMDD mutant HBV. The overall 6-year actuarial patient survival after transplantation was 74.4% and those for HCV(−) and HCV(+) recipients were 81.3% and 66.6%, respectively ( P = .46). The overall 6-year actuarial graft survival was 63.9% and those for HCV(+) and HCV(−) recipients were 68.8% and 57.1%, respectively ( P = .6). Conclusion We conclude that HBcAb(+) liver grafts can be used for both HCV(+) patients and HCV(−) patients who are critically ill, have early hepatocellular carcinoma, or have been exposed to HBV in the past. A short course of HBIg-lamivudine combination therapy provides effective prophylaxis against HBV infection in 89% of recipients of HBcAb(+) grafts.

Systematic review: treatment of chronic hepatitis B virus infection by pegylated interferon

Pegylated interferon-alpha has been shown to be more efficacious than conventional interferon in treating chronic hepatitis C. The use of peginterferon in chronic hepatitis B virus infection with positive hepatitis B e antigen has also been tested in a number of trials since 2003. To systematically summarize and compare the results of these studies. Four studies were identified from PubMed, Medline and reference lists. Data from the trials were extracted and analysed. Where appropriate, combined odds ratio of different trials was calculated. Safety data including serious adverse events and emergence of drug-resistant mutants were recorded. Three of the four trials contained predominantly Asian patients. Peginterferon is found to be superior to lamivudine monotherapy and induced sustained biochemical and virological responses in about one-thirds of patients after 12 months of therapy. Coadministration of lamivudine did not result in improvement in viral suppression. Peginterferon appears to reduce the emergence of YMDD mutation in the combination treatment groups. It was well tolerated with serious adverse events reported in <10% of patients in most trials. Peginterferon-alpha treatment of at least 6 months should be considered as one of the first-line therapeutic options for hepatitis B virus infection.

Noninvasive Markers of Fibrosis for Longitudinal Assessment of Fibrosis in Chronic Liver Disease: Are They Ready for Prime Time?

Over the past decade, there has been a renewed enthusiasm to develop noninvasive serum markers or tests to assess the presence and severity of fibrosis in chronic liver disease. Although a single marker or test has lacked the necessary accuracy to predict fibrosis, different combinations of these markers or tests have shown encouraging results. However, interlaboratory variability and inconsistent results with liver diseases of varying etiologies have made it difficult to assess the reliability of these markers in clinical practice. In this issue of the Journal, Poynard and colleagues describe the "histological" response to lamivudine in patients with chronic HBV over a 24-month period using surrogate serum biomarkers (FibroTest-ActiTest) without corroborating histological data. Investigators found improvement in fibrosis and inflammation in 85% and 91%, respectively, despite the emergence of YMDD mutation in 41.5% of patients. The higher improvement rates reported in this study should be interpreted with caution for a number of reasons including the absence of data on virological response rates, corroboratory histological data, and data on the validity of FibroTest to evaluate fibrosis in a longitudinal manner. Although FibroTest has been studied extensively by the authors of the current study, to date there are only few independent studies. In addition to significant interlaboratory variations, these studies have shown that significant fibrosis could be missed, or conversely significant fibrosis diagnosed in the absence of minimal or no fibrosis in about 15-20% of patients. We may be approaching a time when serum biomarkers may become an integral part of the assessment of patients with chronic liver disease, but published evidence suggests that these markers are not yet ready for prime time.

Lamivudine treatment in maternally transmitted chronic hepatitis B virus infection patients

Lamivudine treatment in chronic carriers who acquired hepatitis B virus through maternal transmission were investigated. A total of 29 subjects (Male:Female, 24:5; mean age, 14.7 +/- 5.6 years) who were hepatitis B e antigen (HBeAg) seropositive for >6 months, alanine aminotransferase (ALT) was >1.3 times of upper limit of normal value, and receiving a 52 week-long treatment, received open-label lamivudine (3 mg/kg per day, maximum 100 mg/day). Another 29 subjects matched for gender, age, liver function, and HBeAg status followed up before the introduction of lamivudine served as the control group. The control group did not receive any treatment and were evaluated at week 52 after the onset of abnormal ALT. Mothers of all study subjects were hepatitis B surface antigen (HBsAg) carriers. A successful treatment response at week 52 was defined as: (i) undetectable hepatitis B virus DNA by real time polymerase chain reaction; (ii) normal ALT; and (iii) HBeAg/anti-HBe seroconversion. Lamivudine-resistant YMDD mutants were checked at week 52. The lamivudine group did not reach a better successful treatment response rate than the control group (17 vs 10%, P = 0.44), except in patients with a baseline ALT >5 times of the upper limit of normal value. YMDD mutants developed in 34% of patients in the lamivudine group. Lamivudine treatment is effective for maternally transmitted subjects with high ALT.

Character of HBV (hepatitis B virus) polymerase gene rtM204V/I and rtL180M mutation in patients with lamivudine resistance

To investigate the relationship between HBV (hepatitis B virus) polymerase gene 180 and 204 sites mutation and lamivudine resistance. One hundred forty-one patients with lamivudine resistance after lamivudine treatment and 60 chronic hepatitis B patients without lamivudine treatment were enrolled in this study. The serum HBV DNA mutation was analyzed by sequence detection via polymerase chain reaction (PCR). The sequences of the same patient were analyzed before and after lamivudine treatment. One hundred and nine lamivudine resistance patients had HBV YMDD (tyrosine-methionine-aspartate-aspartate) mutation. Among them, 45 patients had rtL180M/M204V mutation (41.28%), 28 patients had rtL180M/M204I mutation (25.70%) and 36 patients had rtM204I mutation (33.02%). There were 6 patients with rtL180M mutation in 32 lamivudine resistance patients. Sixty chronic hepatitis patients without lamivudine treatment had no mutations. HBV mutations, which play an important role in lamivudine resistance usually locate at polymerase gene 204 site; 180 site mutation was also observed in these patients. Evaluation of the anti-virus therapy by surveillance of the two sites mutations is of importance.

Determinants of early mortality and benefits of lamivudine therapy in patients with hepatitis B virus‐related decompensated liver cirrhosis

Chronic hepatitis B infection (HBV) is a major health problem worldwide. The prognosis is grave for patients with HBV-related decompensated liver cirrhosis (LC). We evaluated the effectiveness and the determinants of early mortality of lamivudine treatment in patients with HBV-related decompensated LC. Thirty patients with HBV-related decompensated LC and active viral replication were treated with lamivudine 100 mg daily for a median duration of 9 months. Among these patients, five patients died within 3 months. Two patients were lost to follow-up at week 8 and 9. One patient was treated for <6 months. Twenty-two patients were treated over 6 months. Univariate analysis revealed that the total bilirubin (P = 0.008), prothrombin time (P = 0.004), Child-Turcotte-Pugh score (P = 0.005), the model of efd-stage liver disease score (P = 0.004) and stage III hepatic encephalopathy (P = 0.001) were predictive factors of early mortality. Multivariate analysis revealed that the independent factor associated with early mortality was stage III encephalopathy. Among 22 patients, liver function improved markedly after lamivudine therapy. Of the nine hepatitis B e antigen (HBeAg)-positive patients, three had HBeAg seroconversion. Two patients had YMDD mutant and virological breakthrough at 41 and 46 weeks. One of the two had hepatocellular carcinoma and died of hepatic failure at week 125; the other received adefovir and is doing well. Lamivudine appeared to have benefits in viral suppression and significant improvement in liver function in patients with HBV-related decompensated LC. As noted in prior studies, poor baseline liver function is associated with a poor prognosis in Asian patients with decompensated HBV cirrhosis treated with lamivudine.

Response to long‐term lamivudine treatment (up to 5 years) in patients with severe chronic hepatitis B, role of genotype and drug resistance

Lamivudine is effective in suppressing viral replication, normalizing alanine aminotransferase (ALT), and improving histological appearance in HBe positive and negative hepatitis. It is unclear whether hepatitis B virus (HBV) genotype influences the response to lamivudine. We report the long-term response of patients with chronic hepatitis B with and without cirrhosis at baseline treated with lamivudine according to HBV genotype. Retrospective review of charts of all patients treated with lamivudine monotherapy between 1993 and 2002. Response to therapy defined as ALT in the normal range, undetectable HBV DNA, and in the HBeAg positive group loss of HBeAg and/or the development of anti-HBe. HBV DNA measured by the Digene Hybrid capture assay (sensitivity 1.4 x 10(6) copies/mL). YMDD mutation at rtL180M and rtM204V/I measured by restriction digest of amplified products. Genotyping performed by sequencing and phylogenetic tree analysis of the preS region of the virus genome. Seventy-one patients treated with lamivudine for 6 months or more, 53 (75%) were male, average age 47 years, 38 (54%) were HBeAg+ and 33 (46%) HBeAg-. Mean baseline HBV DNA viral titre was 1280.2 copies/mL and 518 copies/mL respectively. Cirrhosis was present in 30 (42%). Sera were examined for YMDD mutations at last patient visit in 61 (86%), and were detected in 45 (74%), there being no association with a particular genotype. Data from up to 5 years on lamivudine indicated no difference in biochemical or virological response between genotypes. Cirrhosis was more prevalent with specific genotypes. We found no influence of HBV genotype on the development of resistance to lamivudine, however liver disease severity was influenced by genotype.

Management of the hepatitis B virus in the liver transplantation setting: A European and an American perspective

Management of the hepatitis B virus in the liver transplantation setting: A European and an American perspective

Liver transplantation for chronic hepatitis B with lamivudine‐resistant YMDD mutant using add‐on adefovir dipivoxil plus lamivudine

Lamivudine treatment in patients with chronic hepatitis B virus (HBV) infection may improve clinical state and suppress viral replication before liver transplantation. Emergence of lamivudine-resistant YMDD mutant is common. We report the results of liver transplantation in 16 patients with pretransplantation YMDD mutants after receiving lamivudine treatment for a median of 738 days (range, 400-1799 days). Adefovir dipivoxil (10 mg daily) was added on to lamivudine for a median of 20 days (range, 8-271 days) before (n = 11) or at (n = 5) liver transplantation, and the combination was continued indefinitely thereafter. Eight patients received additional intravenous hepatitis B immune globulin (HBIG) for a median of 24 months. Fifteen patients with known pre-adefovir HBV DNA levels had a median titer of 14,200 x 10(3) copies/mL (2 x 10(3) to 4,690,000 x 10(3) copies/mL), and 14 had HBV DNA >10(5) copies/mL. All but 1 patient remained positive for HBV DNA (by quantitative polymerase chain reaction [qPCR]) at the time of liver transplantation, and the titer was greater than10(5) copies/mL in 8 patients. The median follow-up after liver transplantation was 21.1 (range, 4.4-68.9) months. One patient (6%) died of an unrelated cause 12.2 months after transplantation, and 15 patients (94%) were alive with the original graft. All patients cleared HBV DNA and had no detectable HBV DNA by qPCR at the latest follow-up. Fourteen patients had cleared hepatitis B surface antigen (HBsAg), but 2 patients who received only adefovir dipivoxil and lamivudine without HBIG remained HBsAg positive after 7.7 and 9.5 months. Serum HBV DNA, however, was negative, and there was no biochemical or histological evidence of recurrence. Adefovir dipivoxil was well tolerated with no significant renal toxicity. In conclusion, a combination of add-on adefovir dipivoxil plus lamivudine therapy provides effective prophylaxis in patients with pretransplantation YMDD mutant that may be actively replicating. The cost effectiveness of additional passive immunoprophylaxis remains to be defined.

Long-term hepatitis B virus dynamics in HIV–hepatitis B virus-co-infected patients treated with tenofovir disoproxil fumarate

The long-term impact of tenofovir disoproxil fumarate (TDF) on hepatitis B virus (HBV) replication has not yet been studied in HIV-HBV-co-infected patients. We conducted a prospective study of HBV-DNA decay kinetics in 28 HIV-HBV-co-infected patients treated by TDF. HBV dynamics were studied using mixed linear models, and baseline factors affecting them were analysed using Cox models. The HBV-DNA load declined by a mean of 4.6 log copies/ml during follow-up (mean 71 weeks), and fell below the detection limit (200 copies/ml) in 21 patients. Inhibition of viral replication by TDF was associated with a decrease in alanine aminotransferase levels (125 versus 68 IU, P < 0.05). HBV-DNA decay was biphasic, with an rapid fall followed by a gradual decline. Baseline factors associated with a steeper first slope in the HBV-DNA decrease were high HBV load, positive hepatitis B e antigen (HBeAg) and YMDD mutations. Baseline factors increasing the time to reach an HBV-DNA level less than 200 copies/ml were high HBV load (150 days when HBV-DNA < 10 log, 316 days when HBV-DNA > 10 log) and positive HBeAg. Previous exposure to lamivudine or TDF-lamivudine did not modify HBV-DNA decrease under therapy in this population with a high prevalence of YMDD mutations. The long-term decline in HBV DNA under TDF is biphasic and is primarily influenced by the initial HBV load. However, the clinical significance of such an association remains moderate, and TDF can be efficiently included in the highly active antiretroviral therapy regimen of HIV-HBV-co-infected patients, regardless of HBV strains and their degree of replication.

Simultaneous detection of two major lamivudine-resistant mutants using competitively differentiated-PCR

Rapid, specific and sensitive methods without advanced equipment are required urgently in developing countries in order to detect or monitor lamivudine-resistant mutants routinely before or in the course of the therapy. A protocol is described for the detection of two major YMDD mutations simultaneously through modifying a previous competitively differentiated-PCR (CD-PCR) by revising the strategy, increasing the number of competitively differentiated primers, increasing the number of labeled haptens, optimizing the amplification system and analyzing its products by enzyme immunoassay. Special care was taken to promote the sensitivity, specificity and the ability of the protocol to detect mutation in mixture of the mutants and wild strain. YMDD mutants in clinical serum samples were detected simultaneously, specifically and rapidly only with assistance of the equipment used widely in highly prevalent areas of hepatitis B virus infection.

Changes in different regions of hepatitis B virus gene in hepatitis B ‘e’ antigen‐negative patients with chronic hepatitis B: the effect of long‐term lamivudine therapy

Lamivudine therapy for chronic hepatitis B has been associated with changes in different regions of the hepatitis B virus nucleotide sequence. To study changes in the sequences of polymerase and precore/core promoter regions of hepatitis B virus, before and during 5 years of therapy with lamivudine. Eighty consecutive samples were taken from 10 chronic hepatitis B 'e' antigen-negative patients. Nine patients carried hepatitis B virus precore mutations during the study. Before therapy, wild type was replaced by A1896 in two (20%) cases. During treatment, A1896 reverted transitory to wild type in five cases (50%) and in one case wild type was replaced by A1896. The continuous detection of precore mutations during therapy was associated with a lower response rate. YMDD mutations were observed in nine cases and both, L180M and M204V/I mutations were simultaneously detected in six cases. About 75% of the patients with M204V mutations were responders and none with M204I or mixed pattern sustained response. Hepatitis B 'e' antigen-negative patients exhibit changes in the precore regions both spontaneously and under lamivudine therapy, the transitory reversion to wild type being most frequently witnessed. Patients carrying M204V mutations are more likely to respond to therapy. If, in further studies, these results are confirmed some patients with YMDD mutations could benefit from prolonging the duration of lamivudine therapy.

The Clinical Impact of Early Detection of the Ymdd Mutant on the Outcomes of Long-Term Lamivudine Therapy in Patients with Chronic Hepatitis B

The early emergence of lamivudine (3TC)-resistant tyrosine-methionine-aspartate-aspartate (YMDD) mutants has been reported during 3TC therapy in patients with chronic hepatitis B (CHB) in hepatitis B virus (HBV)-endemic areas; however, its clinical impact during long-term 3TC therapy is unknown. This study was performed to investigate the impact of the early emergence of YMDD mutants 3 months after the initiation of treatment on the outcomes of long-term 3TC therapy in HBV e antigen (HBeAg)-positive CHB. We analysed YMDD genotypes in consecutive samples from 30 patients with HBeAg positive CHB throughout 3TC treatment using both restriction fragment length polymorphism and mass spectrometric assays. Long-term outcome was compared between patients who had YMDD mutations detected at 3 months and those who had no mutations. YMDD mutation was detected in 16 (53.3%) out of 30 patients at 3 months and only the rtM2041 mutation was found. Cumulative HBeAg loss rates at 3 years was 12.5% and 57.4% in patients who had the rtM2041 mutant and wild-type virus at 3 months, respectively (P=0.010). Cumulative viral breakthrough rates at 3 years was 75.0% and 14.3% in patients who had the rtM204I mutant and wild-type virus at 3 months, respectively (P=0.002). Logistic regression revealed that YMDD mutation at 3 months was significantly related to viral breakthrough within 24 months (P=0.003). In conclusion, early detection for HBV YMDD mutation at 3 months may be useful to predict the long-term outcomes of 3TC therapy in patients with HBeAg-positive CHB in HBV-endemic areas.

Effect of Lamivudine Therapy on the Serum Covalently Closed-Circular (ccc) DNA of Chronic Hepatitis B Infection

To determine the effect of 1-yr lamivudine treatment on serum covalently closed-circular DNA (cccDNA) level. Serum total HBV DNA and cccDNA levels at baseline, week 24, and week 52 were measured in 82 lamivudine-treated patients, 17 of whom received 1-yr placebo and acted as controls. There was a significant reduction in the cccDNA levels from baseline (median 3.0 x 10(6) copies/ml) to week 24 (33,476 copies/ml) and week 52 (48,694 copies/ml) (p < 0.001 for both). The median reduction in cccDNA level at week 24 and 52 were 2.21 and 2.12 logs, respectively, which were significantly greater than those of controls (0.31 log, p < 0.001; 0.2 log, p < 0.001, respectively). Fifteen patients (18.3%) developed YMDD mutations by week 52. Compared to patients without YMDD mutations, patients with YMDD mutations had significantly less median reduction of total HBV DNA level (4.44 vs 3.65 logs, respectively, p= 0.02) and cccDNA level (2.27 vs 1.65 logs, respectively, p= 0.016) at week 24 and significantly less median reduction of cccDNA at week 52 (2.35 vs 0.8 logs respectively, p < 0.001). One-year lamivudine treatment decreased serum cccDNA level by 2 logs. The chance of YMDD mutations at week 52 was related to the magnitude of viral suppression at week 24.

INTERFERON-ALPHA AND EXTENDED LAMIVUDIN COMBINATION THERAPY IN CHILDREN WITH CHRONIC HEPATITIS B INFECTION: EFFICACY AND RATE OF EMERGENCE OF YMDD MUTANT VARIANT

Aim: To evalute the efficacy and rate of breakthrough of IFN-alpha and extended LAM combination therapy in chronic hepatitis B infection. Methods: 38 children (9.8 ± 4.1 years) received simultaneously interferon- alpha (5-10 megaunits /m2for six months) and LAM (4 mg/kg/day, max 100 mg) for median 31 (12 -60) months. LAM was administered until antiHBe seroconversion and was continued for another 6 months in responders. In nonresponders it was stopped after at least 2 years. Histologic evaluation was performed at baseline and end of therapy. Follow up time after end of therapy was median 12 (3-30) months. Results: Pretherapy median ALT and HBV DNA were 60 U/L and 2000 pg/ml. End of therapy ALT normalization (71.1%), HBeAg loss with anti HBeAg seroconversion (34.2%), HBsAg clearance (5.2%), HBV DNA clearance (36.8%), histologic (47.6%), complete (34.2% ) and sustained (31.7%) response were achieved. Relapse rate was 7.6%. Predictive factor in responders was high baseline ALT (p < 0.01). Breakthrough and YMDD mutant rate were 65.8% and 55.2%.Baseline ALT was lower in patients with breakthrough (p < 0.01) but no significant difference in sex, age, baseline HBV DNA level and HAI score were found (p > 0.05). In children with breakthrough baseline and end of therapy ALT were not significantly different, but HBV DNA was lower than baseline (p < 0.01). In follow-up, 22.2% of nonresponders showed ALT elevation and 8% (one with YMDD mutant) achived response. Conclusion: Response rate of IFN and extended LAM therapy was not higher than previously reported monotherapy or combination therapies. Histologic response occured in 47.9% of patients. Relapse rate was low. High ALT level was the predictor of succesful therapy. HBe Ag seroconversion continued with extended therapy, but mutation rate also increased. Breakthrough was associated with lowel ALT. Hepatitis flare was not observed in nonresponders. Because of development of YMDD mutants, the benefit versus risk of LAM therapy must be weighed carefully.

LONG TERM LAMIVUDINE TREATMENT FOR CHRONIC HEPATITIS B INFECTION IN CHILDREN UNRESPONSIVE TO INTERFERON

Background: Three years ago we reported the results of an open prospective study that investigated the efficacy and safety of one year lamivudine treatment in children (n = 22) with chronic hepatitis B (CHB) who failed interferon treatment. We showed that one year lamivudine treatment resulted in decreased HBV replication and improved ALT values, but an exceptionally high rate (65%) of lamivudine-resistant mutants. Aims: The present study examined the efficacy and safety of prolonged lamivudine therapy in this group of children (aged 8.5-19 years of age). Methods: This cohort of 22 children (17 boys, 5 girls) was prospectively followed for a median of 3.6 years (range 3 to 4 years). Children were treated with lamivudine 3 mg/kg/day up to 100 mg/day, and were instructed to come back to follow up every 4 months. At each visit children underwent physical examination, compliance to treatment and side effects were recorded and blood tests were performed, including blood count, liver enzymes and bilirubin, HBeAg/antiHBe, HBV DNA and HBV mutants. Results: Of the 22 children that started the study, only five were taking lamivudine after 4 years. The reasons for drop out from the study were lack of adherence to treatment (10/17), HBeAg/antiHBe seroconversion (5/17) and lack of response to treatment (2/17). Children who maintained lamivudine treatment at the end of 4 years had persistent ALT normalization and low HBV DNA levels and YMDD mutant was present only in one child. No clinical adverse effects were recorded during lamivudine treatment or after treatment termination. Transient ALT flare up (×12 ULN) was present in one patient. Two patients showed persistent elevated CPK values (1753 IU/L to 478 IU/L) with normal blood gases and serum lactate. Conclusions: In this cohort, children with CHB who failed to respond to previous IFN therapy and were treated with lamivudine for up to 4 years, had high rates of drop out, mainly because of lack of compliance to treatment and poor HBeAg seroconversion rate, suggesting that prolonged lamivudine treatment in children is hard to achieve and probably not efficient.

Relationship between B virus hepatitis genotypes and therapeutic efficacy in early treatment for chronic hepatitis B by using lamivudine

To investigate the relationship between hepatitis B virus (HBV) genotype and therapeutic efficacy during the early phase of lamivudine treatment. Totally 595 patients with chronic hepatitis B were treated with lamivudine 100 mg/day for 12 months. HBV genotypes, contents of HBV DNA, HBeAg/anti-HBe and YMDD mutation after lamivudine treatment for 12 months were determined. The data were analyzed with SPSS software. In 595 patients, 8 (1.4%) were genotype A; 53 (8.9%) genotype B; 360 (60.5%) genotype C; 112 (18.8%) were coinfection of genotype B and C; 14 (2.4%) of A and C; 15 (2.5%) A and B; 6 (1.0%) of A, B, and C, and remaining 27 (4.5%) were unspecified. Patients were treated with lamivudine 100 mg/day for 12 months. Genotype B with HBV DNA levels turned to be negative (HBV DNA < 0.1 ng/L) was 87.2%, genotype C was 89.51%, coinfection of genotype B and C was 93.04% (P > 0.05). HBeAg seroconversion of genotype B was 11.65%, of genotype C was 20.64%, and of coinfection of genotype B and C was 18.57% (P > 0.05). All 69 strains of YMDD mutation were detected after lamivudine treatment for 12 months, in which genotype B was in 16.98%, genotype C in 15.38%, and coinfection of genotype B and C was in 13.86% (P > 0.05). There was no difference in HBV genotypes and the rate of development of YMDD mutations, HBeAg seroconversion, descending of HBV DNA level in Chinese patients with chronic hepatitis B.