[Assessment of the PCR-Southern blot technique for the analysis of viremia in patients with acute hepatitis A]

Assessment of viremia in hepatitis A virus (HAV) infection is not frequently performed with conventional methods because the techniques used are laborious, have low sensitivity are usually performed in feces. The aims of this study were to develop a polymerase chain reaction (PCR) and Southern blot technique to detect HAV-RNA in the serum of patients with acute HAV infection and to determine the relationship between HAV-RNA and anti-HAV IgM and alanine aminotransferase (ALT) levels. The presence of HAV-RNA was studied in 26 serum samples from 21 patients with acute hepatitis A. We also studied 11 samples from patients with acute hepatitis B and 15 samples from patients with non-A, non-E hepatitis. HAV-RNA was detected in 10 (38%) of the 26 serum samples from patients with acute hepatitis A. Simple PCR was positive in 5 samples and PRC-Southern blot was positive in 10. All the serum samples obtained during the first week of onset were HAV-RNA positive and 50% of those obtained during the second week were positive. None of the serum samples obtained after the second week of onset were HAV-RNA positive. None of the serum samples from the 11 patients with acute hepatitis B or from the 15 patients with non-A, non-E acute hepatitis were positive for HAV-RNA. No significant relationship was detected between HAV-RNA detection and an IgM anti-HAV or ALT positive result. In conclusion, the presence of HAV-RNA in acute hepatitis A is frequent but the PCR Southern blot technique is required for detection, which is transitory during the first weeks after onset.

HEV identified in serum from humans with acute hepatitis and in sewage of animal origin in Spain

BACKGROUND/AIMS

Hepatitis E virus (HEV) is an enterically transmitted pathogen that appears sporadically in non-endemic countries. We studied HEV as a causal agent of acute hepatitis cases in the Spanish population, and the role of pigs as an animal reservoir.

METHODS

The presence of HEV-RNA was analysed by nested polymerase chain reaction in 37 serum samples from patients with acute viral hepatitis, 48 porcine serum samples, 6 pig faecal samples and 12 slaughter-house sewage samples. Presence of antibodies was also tested in porcine sera.

RESULTS

HEV-RNA was found in 3 human serum samples from patients presenting IgG anti-HEV antibodies. Nucleotide sequence analysis identified 2 strains with 93.4% identity, phylogenetically most closely related to the Greece1 isolate, and more closely related to North American and other European strains than to those from endemic regions. HEV-RNA was also detected in slaughterhouse sewage mainly from pigs, presenting 92-94% nucleotide similarity compared to the strains detected in the human sera. Twenty-five per cent of the pigs tested presented IgG anti-HEV antibodies.

CONCLUSIONS

These data suggest that the HEV could be more widespread than previously thought, and present new evidence of the close relationship between HEV strains detected in pigs and those from acute hepatitis patients.

Hepatitis A and B in children and adolescents--what can we learn from Puglia (Italy) and Catalonia (Spain)?

Viral hepatitis remains a major contributor to the global disease burden. Mass immunisation strategies against hepatitis B have been adopted by more than 90 developing and industrialised countries. Countries with low hepatitis A endemicity are experiencing cyclical outbreaks and an epidemiological shift, with larger numbers of individuals at risk of infection at an older age, resulting in increased morbidity. The high cost of outbreaks in these countries has made immunisation strategies cost-effective. The development of a vaccine against hepatitis A and a combined vaccine against hepatitis A and hepatitis B offers potentially exciting opportunities for a preventative approach in areas of both low and high endemicity. Existing mass immunisation programmes against hepatitis B will facilitate the adoption of joint strategies illustrated by the examples of Puglia (Italy) and Catalonia (Spain).

Cost-effectiveness of combination therapy for naive patients with chronic hepatitis C

BACKGROUND/AIMS

The higher initial cost of combination therapy is a factor which may discourage its use in naive patients with histologically mild or moderate chronic hepatitis C. However, chronic hepatitis C is a slowly progressive disease associated with a decrease in life expectancy and quality of life. The objective of this study was to determine if the incremental sustained response rate of combination therapy is sufficient to outweigh its extra cost.

METHODS

Chronic hepatitis C progression was studied using a Markov model in which cohorts of patients were treated with combination therapy for 6-12 months or with interferon for 12 months. The sustained virological response rates applied were 43, 35 and 19%, respectively, for combination therapy for 12 months, for 6 months and for interferon for 12 months. Costs for each clinical state were calculated according to clinical practice in Spain.

RESULTS

In a 30-year-old patient with moderate chronic hepatitis C, combination therapy for 12 months increases life expectancy by 4.1 years compared with interferon for 12 months. In mild disease, the increase in life expectancy is lower. The cost per life-year saved in patients with chronic hepatitis C ranges from 880 to 64.421 euros depending on the age of the patient, the degree of hepatic lesion and the type and duration of therapy. Compared to other treatments accepted as standard practice in other therapeutic areas, combination therapy for chronic hepatitis C is cost-effective.

CONCLUSIONS

In patients of any age with moderate chronic hepatitis C and those with mild disease under 50 years of age, combination therapy for 12 months is the most cost-effective schedule, whereas in older patients with mild hepatitis, combination therapy for 6 months is the preferred option based on cost-effectiveness criteria.

[Prevalence and incidence of hepatitis A in patients with hepatitis B and C]

BACKGROUND

Patients with chronic hepatitis are in risk to acquire a fulminant hepatitis associated with hepatitis A virus superinfection.

PATIENTS AND METHODS

Antibodies against hepatitis A were study in serum from 353 patients with chronic hepatitis B or C.

RESULTS

The prevalence of IgG-HAV antibodies was 81% in chronic hepatitis C patients, and 77% in chronic hepatitis B patients. The presence of anti-HAV antibodies was related to the patients' age. None case of acute hepatitis A in chronic hepatitis patients was detected.

CONCLUSIONS

The prevalence of anti-HAV antibodies is high in patients with chronic viral hepatitis but the incidence of the disease is low. Hepatitis A vaccination should do with previously screening.

Quantification of serum hepatitis C virus RNA with daily or standard interferon doses plus ribavirin in nonresponder patients with chronic hepatitis C

Less than 10% of patients with chronic hepatitis C infected with genotype 1 achieve a sustained response with 12 months of interferon therapy. Viral kinetics studies have shown that HCV may replicate in less than 24 hr, generating over 10(12) copies per day and suggesting the need for more aggressive therapy. The aim of the study was to determine the effect of a higher and daily dosage of IFN-alpha2b plus ribavirin on the viral load and on the response rate in patients infected by genotype 1 and previous nonresponders to interferon. Ten patients with chronic hepatitis C infected with genotype 1 were allocated to receive IFN-alpha2b, 5 MU daily or three times a week for four weeks followed by 5 MU three times a week until week 24 plus ribavirin for the entire period. At week 4 of therapy, a 2 log reduction in HCV RNA levels was achieved in three (60%) patients in the daily group and in one (20%) patient in the three times a week group. At week 24, HCV RNA was negative in four of the five patients in the three times a week group, and three of the four patients in the daily group had a virological response. However, in follow-up, none of these patients experienced a sustained response. The safety of and ability to tolerate the combination therapy was good, anemia being the most common adverse effect. In conclusion, patients previously not responding to interferon achieved a greater virological reduction early in combination therapy compared to a three times a week interferon schedule. However, the virological response at the end of therapy was similar between the two regimens, and no sustained response was observed in any of the treatment groups.

Rapid method for the detection of anti-HCV antibodies in patients with chronic hepatitis C

OBJECTIVE

to evaluate the usefulness of a simple, rapid, qualitative technique (MedMira Rapid Test) to detect antibodies against hepatitis C virus (HCV) and compare this approach with an immunometric technique in patients with chronic hepatitis C infected with different genotypes.

METHODS

anti-HCV antibodies were determined with the MedMira rapid technique and an immunometric method in samples from 138 patients with chronic hepatitis C infected with different HCV genotypes, and in 50 samples from healthy individuals.

RESULTS

the MedMira rapid technique detected anti-HCV antibodies in 135 (98%) of 138 serum samples from patients with chronic hepatitis C, whereas the immunometric method gave positive results in all 138 samples. Three of the 138 anti-HCV-positive samples identified with the immunometric method and confirmed by inmunoblotting were repeatedly negative with the MedMira rapid technique. Two of these samples were genotype 1 and the third was not genotyped. All samples from the control group were negative for anti-HCV antibodies by both methods. The sensitivity and specificity of the MedMira rapid technique relative to the immunometric technique were 98% and 100% respectively.

CONCLUSION

the MedMira rapid technique is a quick, specific and sensitive method that is easy to use by nonspecialized personnel, and is a good alternative to other, slower methods for the diagnosis of chronic hepatitis C.

Prospects for vaccination against hepatitis A and B in Catalonia (Spain)

Catalonia is in an area of intermediate endemicity for hepatitis A virus (HAV) infection. An Expert Committee has recently proposed the implementation of universal hepatitis A vaccination for 12-year-olds, based on the fact that no risk factors can be identified for hepatitis A in 50% of cases, and also that selective vaccination targeted at high-risk groups has a limited potential to reduce the incidence of hepatitis A. The well-established programme of hepatitis B vaccination of pre-adolescents in Catalonian schools has high levels of vaccination coverage. This will provide a means to introduce hepatitis A vaccination in a cost-effective way in schools, by replacing the single vaccine with the combined hepatitis A and B vaccine. High-risk groups will also continue to be targeted. A pilot programme has commenced in the 1998/1999 school year and will be evaluated after 3 years. If it is successful, it will be extended indefinitely.

What to do when standard therapy fails

An important group of patients with chronic hepatitis C do not respond to interferon (IFN) therapy. Compared with untreated patients with chronic hepatitis C, non-responders have a higher percentage of cirrhosis, are more frequently infected by genotype 1 and usually have a viral load above 2 x 106 copies/ml. Also, patients with cirrhosis have lower life expectancy and higher risk of clinical complications, and therefore, are most in need of effective treatment strategies. There is no evidence that the re-treatment of non-responders with a standard regimen of IFN or more prolonged IFN therapy achieves a sustained biochemical or virological response. Between 20% and 40% of non-responder patients treated with IFN therapy for more than two years had an hepatic improvement in liver histology associated with a decrease in hepatitis C virus-ribonucleic acid levels. In contrast, combination therapy with IFN and ribavirin for six months now results in sustained response rates between 6% and 29% depending on the viral genotype and the presence or absence of cirrhosis. Patients infected with genotype 2 and 3 have a higher probability of achieving a sustained virological response than those infected by genotype 1. Currently, different studies are underway to determine whether high-dose IFN and/or induction therapy combined with ribavirin for more prolonged periods of time could increase the sustained response rate in non-responders. No other drugs appear to be efficacious in these patients, except the combination of IFN, ribavirin and amantadine which has shown interesting results in a preliminary trial but they need to be confirmed in further studies. These findings suggest that combination therapy is beneficial and can be recommended for some non-responder patients until other new therapies are available.

Rapid detection of lamivudine-resistant hepatitis B virus polymerase gene variants

The amino acid substitution from methionine to valine or isoleucine at the YMDD (tyrosine, methionine, aspartate, aspartate) motif of the HBV polymerase gene is the main mutation responsible for resistance to lamivudine treatment. Detection of emerging HBV variants by direct sequencing of the HBV genome is excessively time-consuming for studying large numbers of clinical samples. The aim of the study was to analyse the emergence of lamivudine-resistant HBV genotypes by means of restriction fragment length polymorphism (RFLP) of the PCR product generated from a fragment of domain C of the polymerase gene, in clinical samples from patients receiving treatment. The results with this method were compared with those obtained with a direct sequencing technique. In total, 139 serum samples were studied from 37 patients with chronic hepatitis B, obtained at pre-treatment and at 9, 12, 18 and 24 months of treatment. Variants were detected by cleavage of the products of the three PCRs with the following enzymes: FokI (identifies the normal variant, YMDD, and the mutant variant YVDD), SspI (identifies the mutant variant, YIDD) and Alw44I (identifies the variant, YVDD). The digested fragments were separated by electrophoresis in 3% agarose gel. Of the 139 serum samples analysed, the wild-type YMDD sequence was detected in 106 (76%), the YVDD variant in 20 (15%) and the YIDD variant in 13 (9%) cases. The non-mutated variant, YMDD, was detected in all the pre-treatment samples. After 9 months of treatment the mutant variant was detected in four of 37 serum samples analysed (11%) (two YVDD and two YIDD). At 12 months, 12 of the 37 serum samples (32%) showed mutations in the YMDD sequence (seven YVDD and five YIDD). Among the 16 serum samples obtained at 18 months, nine had the YMDD variant (56%) (seven YVDD and two YIDD). At 24 months, variants in the YMDD sequence were detected in eight of the 12 patients treated (66%) (four YVDD and four YIDD). HBV genotypes were confirmed by direct sequencing, with consistent results. In 45% of cases, the emergence of HBV variants was not associated with ALT breakthrough. The PCR-RFLP assay used in this study, in perfect concordance with direct sequencing, is an accurate method for genotyping lamivudine-resistant HBV variants. Since it is a rapid low-cost technique, PCR- RFLP is suitable for large-scale screening of these polymorphisms in clinical samples.

Genetic alterations in the S gene of hepatitis B virus in patients with acute hepatitis B, chronic hepatitis B and hepatitis B liver cirrhosis before and after liver transplantation

BACKGROUND

Several studies have shown that hepatitis B immunoglobulin (HBIG) imposes a selection pressure on the hepatitis B virus (HBV) S gene, and that the emergence of mutations in this region would make reinfection after orthotopic liver transplantation (OLT) possible.

AIMS

This study was undertaken to analyze the presence of HBV S-gene mutations in the different stages of HBV infection and the relationship between HBIG therapy and the emergence of mutations in liver transplant recipients.

METHODS

The frequency and location of mutations in the coding region of the HBV S gene were studied by PCR and direct sequencing in 30 patients (7 with acute self-limited hepatitis B, 16 with chronic hepatitis B and 7 recipients of (OLT) for HBV-related end stage liver disease who became reinfected).

RESULTS

The average number of amino acid changes was higher in patients with a more advanced stage of disease, 0.57 mutations/100 positions in acute hepatitis B and 1.57 in chronic hepatitis B (1.28 in HBeAg-positive and 1.8 in anti-HBe-positive patients). The average number of substitutions in the transplanted patients was 2.7 before OLT and 3 after OLT. No amino acid substitutions were detected in the "a" determinant of HBsAg in acute hepatitis B, however, 8 substitutions were observed in 6 chronic patients. In 3 OLT patients, 4 substitutions were observed in samples before and after OLT. One of these patients, who had protective levels of anti-HBs, showed 3 additional new amino acid substitutions after OLT, suggesting escape mutant selection by the effect of HBIG therapy. No changes were observed between the consensus sequences obtained several years before and after transplantation, indicating consensus sequence stability.

CONCLUSION

These results show that there is an accumulation of HBV S-gene mutations in HBV-related end-stage liver disease. Prophylaxis with HBIG mainly obtained from acute self-limited hepatitis patients who have a highly homogeneous viral population, may be one factor underlying the reinfection after liver transplantation.

[One year treatment with lamivudine in different hepatitis B virus related hepatic diseases]

BACKGROUND

Three month administration of lamivudine in patients with chronic hepatitis B produces a transitory inhibition of the DNA of the hepatitis B virus (HBV).

AIM

The aim of this study was to evaluate the efficacy and safety of one year treatment with lamivudine in patients with chronic hepatitis B and liver transplantation (LTx) with recurrence of HBV infection.

PATIENTS AND METHODS

Sixteen patients with chronic hepatitis B, 4 patients with decompensated hepatic cirrhosis and 4 patients having undergone LTx with recurrence of HVB infection were treated with the oral administration of 100 mg/day of lamivudine for one year.

RESULTS

At 3 months of treatment, the HBV-DNA became negative in 94% of the cases of chronic hepatitis B, in 10% of those with decompensated hepatic cirrhosis and in 100% of the cases of LTx. At one year of treatment, the HBV-DNA was negative in 81% of the chronic hepatitis B, in 100% of the decompensated cirrhotics and in 100% of the LTX cases which survived. The tolerance to treatment was excellent in all the cases. In 34% of the cases, mutations were observed in the gene of the polymerase DNA at one year of treatment.

CONCLUSIONS

Lamivudine produces intense, rapid inhibition in viral replication not only in chronic hepatitis B but also in cases of decompensated cirrhosis or recurrence following liver transplantation. Around 30% of the patients undergoing one year of treatment with lamivudine developed gene mutations of the HBV polymerase.

[Interferon treatment of chronic viral hepatitis in Catalonia, Spain. Retrospective analysis]

AIM

To analyze the results of interferon treatment in chronic hepatitis B and C in Catalonia, Spain, during the first two years of the Assessment Board of the therapeutic use of interferon.

MATERIAL AND METHODS

A retrospective analysis of the results of 2,142 applications for interferon treatment for chronic hepatitis B (n = 158) and C (n = 1,970) from January, 1993 to December, 1994 presented to the Interferon Assessment Board, was performed by the study of the data of the applications-questionnaires send by the applying physicians.

RESULTS

The global rate of response to the questionnaires was of 85%. For chronic hepatitis C, three treatment schedules were evaluated included 936 cases out of the 1,931 authorizations. A sustained response was observed in 20% of the cases treated with 3 MU of interferon for 6 months, in 32% of those treated over 12 months and 20% of those treated with 5-6 MU of interferon for 6 months. The patients with chronic hepatitis B were divided into 2 groups in relation to the presence or absence of HBeAg. Of the 153 applications, 34 belonging to HBeAg positive patients and 52 anti-HBe positive patients who received interferon treatment at 5-10 MU three times per week for 4-6 months were evaluated. Sustained response was observed in 44% of the chronic hepatitis HBeAg positive cases and in 25% of the anti-HBe cases treated. In general, response to treatment was higher in females and in those subjects under the age of 40 years than in male and in older subjects. No differences were observed in the response among the different types of interferon. Withdrawal from treatment due to adverse effects or because of the patient's wish was similar among the patients with chronic hepatitis B (5%) and C (3%), being higher in those undergoing treatment for a longer period of time.

CONCLUSIONS

The data obtained from the Interferon Assessment Board for the treatment of viral hepatitis demonstrates the use of very variable schedules of this drug, especially in chronic 85% and complete evaluation was achieved in 54% of the chronic hepatitis B and in 48% of the cases of chronic hepatitis C.

Efficacy of lamivudine in patients with hepatitis B e antigen-negative/hepatitis B virus DNA-positive (precore mutant) chronic hepatitis B. Lamivudine Precore Mutant Study Group

This placebo controlled, double-blind study evaluated the efficacy and safety of lamivudine in patients with hepatitis B e antigen (HBeAg)-negative/hepatitis B virus (HBV) DNA-positive chronic hepatitis B. Patients were randomized to receive 100 mg lamivudine orally once daily for 52 weeks (n = 60) or placebo for 26 weeks (n = 65). Patients who were HBV DNA positive at week 24 were withdrawn at week 26. The primary efficacy endpoint was loss of serum HBV DNA plus normalization of alanine transaminase (ALT) at week 24. A significantly higher proportion of patients receiving lamivudine (63%) had a complete response at week 24 compared with patients receiving placebo (6%) (P <.001). Secondary efficacy parameters included histological response from baseline to week 52 in the lamivudine-treated patients. At week 52, 60% of lamivudine-treated patients with liver biopsy specimens available showed histological improvement (>/=2-point reduction in Knodell necro-inflammatory score), 29% showed no change, and 12% worsened. In a ranked assessment of pretreatment and post-treatment biopsy pairs 11% improved, 86% showed no change, and 2% worsened in fibrosis. At week 52, 27% of patients receiving lamivudine had YMDD (tyrosine-methionine-aspartate-aspartate amino acid motif of HBV polymerase) variant HBV. The incidence of adverse events and laboratory abnormalities was similar in both groups. In conclusion, lamivudine treatment results in a significant virological and biochemical improvement compared with placebo, induces an improvement or no change in histology in most patients, and is well tolerated. The response to lamivudine therapy in HBeAg-negative patients is similar to the response reported in previous studies of patients with HBeAg-positive chronic hepatitis B.

[Quantitative determination of HBV-DNA in chronic hepatitis B: comparison of three methods]

The aim of this study was to evaluate a technique of quantitative determination of DNA-HBV in serum, bDNA Quantiplex, in a series of 90 patients with chronic HBV infection: 75 with chronic hepatitis B (24 HBeAg positive and 51 with anti-HBe) and 15 asymptomatic carriers of HBV (anti-HBe positive). The results were related to DNA-HBV determination by hydridation techniques in dot-blot and PCR. DNA-HBV was detected by the Quantiplex bDNA technique in 61 (81%) of the 75 patients with chronic hepatitis B, in 24 (100%) of the 24 HBeAg positive patients and in 37 (72%) of the 51 anti-HBe positive (p < 0.05) patients and in none of the asymptomatic HBV carriers. The median of DNA-HBV concentration was 4,000 pg/ml in the hepatitis HBeAg and 71 pg/ml in the ati-HBe positive (p < 0.05). A significant relation was observed between the ALT value and the DNA-HBV concentration (p < 0.05). DNA-HBV by dot-blot was positive in 22 (29%) of the chronic hepatitis B and in none of the asymptomatic HBV carriers. DNA-HBV was not observed by dot-blot in 39 patients positive for DNA-HBV by the Quantiplex bDNA technique. DNA-HBV by PCR was identified in 65 (87%) of the chronic hepatitis B and in one of the asymptomatic HBV carriers. The sensitivity of the Quantiplex bDNA technique (98% versus the PCR technique) is much greater than that observed with dot-blot. In conclusion, the determination of DNA-HBV by the Quantiplex bDNA technique may be considered a good method for evaluating the viremia and degree of viral replication in patients with chronic hepatitis B.

Hepatitis delta genotypes in chronic delta infection in the northeast of Spain (Catalonia)

BACKGROUND/AIMS

Based on genetic analysis of variants obtained around the world, three genotypes of the hepatitis delta virus have been defined. Hepatitis delta virus variants have been associated with different disease patterns and geographic distributions. To determine the prevalence of hepatitis delta virus genotypes in the northeast of Spain (Catalonia) and the correlation with transmission routes and clinical disease, we studied the nucleotide divergence of the consensus sequence of HDV RNA obtained from 33 patients with chronic delta hepatitis (24 were intravenous drug users and nine had no risk factors), and four patients with acute self-limited delta infection.

METHODS

Serum HDV RNA was amplified by the polymerase chain reaction technique and a fragment of 350 nucleotides (nt 910 to 1259) was directly sequenced.

RESULTS

Genetic analysis of the nucleotide consensus sequence obtained showed a high degree of conservation among sequences (93% of mean). Comparison of these sequences with those derived from different geographic areas and pertaining to genotypes I, II and III, showed a mean sequence identity of 92% with genotype I, 73% with genotype II and 61% with genotype III. At the amino acid level (aa 115 to 214), the mean identity was 87% with genotype I, 63% with genotype II and 56% with genotype III. Conserved regions included the RNA editing domain, the carboxyl terminal 19 amino acids of the hepatitis delta antigen and the polyadenylation signal of the viral mRNA.

CONCLUSIONS

Hepatitis delta virus isolates in the northeast of Spain are exclusively genotype I, independently of the transmission route and the type of infection. No hepatitis delta virus subgenotypes were found, suggesting that the origin of hepatitis delta virus infection in our geographical area is homogeneous.

[Cost effectiveness of the treatment of chronic hepatitis C with interferon-alpha]

The purpose of this study was to assess the cost-effectiveness of the treatment of chronic hepatitis C with interferon in Spain. Disease progression was studied using a Markov model through which an untreated cohort of 1000 patients was compared with cohorts treated with interferon 3 MU three times per week for 6, 12 or 18 months. Treatment cost, patients quality of life, and survival were the parameters evaluated. Using the perspective of the National Health System, an 18 month treatment with alfa interferon offers a better cost-effectiveness ratio than a treatment of 6 or 12 months duration. The age of the patient at the start of treatment is one of the most influential factors on the cost-effectiveness of treatment. In patients under 45 years of age, a net cost saving is observed with all treatment schedules, especially with 18 months treatment, due to significant reductions in severe complications of disease progression. In patients aged 45-60, 18 months treatment incurs a net cost, although important gains are made in survival and quality of life. In patients over 65 years of age, the economic benefits of prolonged treatment do not compensate the extra cost. In conclusion, treatment of chronic hepatitis C with alfa interferon should begin as early as possible, especially in young patients. In cases of favourable response, treatment should be extended to 18 months, in order to obtain a higher rate of sustained response, avoid progression of hepatic disease and achieve a more favourable cost-effectiveness ratio.

Transient emergence of hepatitis B variants in a patient with chronic hepatitis B resistant to lamivudine

BACKGROUND

Lamivudine is a cytosine nucleoside analogue that inhibits hepatitis B virus replication. Resistance to lamivudine monotherapy has been reported in patients who received lamivudine to prevent recurrent hepatitis B virus infection after liver transplantation. No cases of resistance have been described in patients who did not clear HBV DNA during lamivudine therapy.

METHODS

We report the case of an adult patient with chronic HBeAg-positive hepatitis B who had a hepatitis flare during lamivudine therapy. The patient did not respond to lamivudine and, at 4 months of treatment, developed a significant serum alanine aminotransferase elevation. Alanine aminotransferase levels remained elevated for 4 months and returned to baseline spontaneously. Lamivudine therapy was administered for 1 year (52 weeks) and after withdrawal, alanine aminotransferase levels remained elevated.

RESULTS

Sequencing studies of HBV DNA at week 52 showed the emergence of a lamivudine-resistant variant associated with two point mutations in the hepatitis B virus polymerase gene: one mutation led to amino acid substitution of methionine to valine at residue 552, in the highly conserved tyrosine-methionineaspartate-aspartate motif, part of the active site of the polymerase; the second mutation consisted of a substitution of leucine to methionine at residue 528. At week 54 of follow-up, both mutations were undetectable.

CONCLUSION

This observation demonstrates the transient emergence of HBV variants in the course of therapy in a patient resistant to lamivudine therapy.