Search PubMed⌕ Search

Biomedical subjects

M Buti

Publications and source records attributed to M Buti.

At least 19 recordsLinked to original sources
PubMed2006

Cost-effectiveness analysis of lamivudine and adefovir dipivoxil in the treatment of patients with HBeAg-negative chronic hepatitis B.

AIM: To estimate the cost-effectiveness over a 4-year duration of lamivudine and adefovir dipivoxil for patients with hepatitis B 'e' antigen-negative chronic hepatitis B. METHODS: A decision analysis model has been used to perform a cost-effectiveness analysis of lamivudine and adefovir dipivoxil from the perspective of the Spanish Public Health System. Data were obtained from clinical trials. RESULTS: For the base-case, the total estimated cost per patient treated with lamivudine or adefovir dipivoxil for 4 years was 11,457 and 21,939 respectively. Virological response at year 4 for the lamivudine arm was 40.4% and 78.0% for the adefovir dipivoxil arm. The average cost-effectiveness ratio (cost per responding patient at year 4) was 28,375 for the lamivudine arm and 28,132 for the adefovir dipivoxil arm. The incremental cost-effectiveness ratio of adefovir dipivoxil vs. lamivudine (cost per additional responding patient with adefovir dipivoxil) was 27,872, demonstrating that this cost was slightly lower than the average cost-effectiveness ratios of adefovir dipivoxil or lamivudine. The sensitivity analysis demonstrated that the factors that most influence the cost-effectiveness were the response to adefovir dipivoxil and lamivudine at year 4. CONCLUSION: Long-term treatment with adefovir dipivoxil is a cost-effective strategy in patients with chronic hepatitis B 'e' antigen-negative hepatitis.

Adenine↗
PubMed2006

Hepatitis B virus genotypes and G1896A precore mutation in 486 Spanish patients with acute and chronic HBV infection.

This study aims to determine the prevalence of hepatitis B virus (HBV) genotypes (A-F) and their association with the G1896A precore mutation in 486 patients positive for HBV surface antigen. Genotypes were determined by RFLP and precore mutation by real-time PCR. Genotypes D (48.1%) and A (39.5%) were the most common, followed by F (4.1%) and B, C and E (<1%). The A to D ratio (A:D) was 1.4 in HBeAg+ chronic hepatitis B (CHB), 0.6 in HBeAg- CHB and 1.4 in HBeAg- inactive carriers. Distribution of these genotypes was different between HBeAg+ CHB and HBeAg- CHB (P = 0.02), and between HBeAg- CHB and HBeAg- inactive carriers (P = 0.009). Genotype A was the most prevalent in HBeAg+ CHB with elevated alanine aminotransferase (ALT) (68.6%) and genotype D in HBeAg+ CHB with fluctuating ALT (60.7%). There was a difference in genotype prevalence between chronic and acute infection (P = 0.03). The precore mutant correlated with high levels of HBV-DNA in genotype d HBeAg- CHB. Genotype D is not as highly prevalent in Spanish patients as would be expected in a Mediterranean area. The unequal prevalence of genotypes between acute and chronic infection suggests that genotype A is associated with a higher tendency to cause chronic infection.

Adolescent↗
PubMed2005

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.

BACKGROUND: Lamivudine therapy for chronic hepatitis B has been associated with changes in different regions of the hepatitis B virus nucleotide sequence. AIM: 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. METHODS: Eighty consecutive samples were taken from 10 chronic hepatitis B 'e' antigen-negative patients. RESULTS: 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. CONCLUSION: 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.

Adult↗
PubMed2005

Study on the efficacy and safety of adefovir dipivoxil treatment in post-liver transplant patients with hepatitis B virus infection and lamivudine-resistant hepatitis B virus.

Hepatitis B virus (HBV) recurrence and de novo HBV infection are frequent events in liver transplantation recipients. Treatment with lamivudine is initially efficient in both infections but the incidence of lamivudine-resistant HBV emergence increases over time. Adefovir appears to be promising in post-liver transplantation patients with recurrent HBV infection and lamivudine-resistant HBV. This study analyzed adefovir treatment in 42 post-liver transplantation patients who developed recurrent HBV or de novo HBV infection with lamivudine-resistant HBV (54.8% HCV-coinfected). Patients received 10 mg of oral adefovir once daily for a mean period of time of 21.5 months (range from 12 to 31 months). In 62.9% of patients, ALT levels decreased significantly. Serum HBV-DNA was undetectable in 64% of the cases. Twenty percent of patients lost HBeAg marker and 13.3% of them developed anti-HBe. In 9.5% of recipients, HBsAg became negative. There was no significant change in serum creatinine levels. In only one patient was worsening of the renal function detected, making dose adjustment necessary. No other side effects were reported. Our results confirm the efficacy and safety of adefovir treatment in post-liver transplantation patients with lamivudine-resistant HBV, neither were adefovir-resistant mutations identified in patients after 21 months of therapy, nor were there adverse events, especially renal toxicity.

Adenine↗
PubMed2004

[Genotype and phenotypic expression of hereditary hemochromatosis in Spain].

INTRODUCTION: The prevalence of C282Y homozygosity in patients with hereditary hemochromatosis (HH) has been reported to be markedly lower in the Mediterranean Basin than in northern Europe. In Spain, the available data are contradictory and limited to small series in specific regions. The objective of this study is to determine the prevalence of the 2 main HFE gene mutations in a large series of unrelated Spanish patients with HH from different geographical origins. PATIENTS AND METHOD: The criteria for HH diagnosis were: repeat serum transferrin saturation index (> 45% plus C282Y homozygosity and/or hepatic iron index (> 1.9 of dry liver weight in non-cirrhotic patients or (> 4.1 in patients with liver cirrhosis. Cases in related individuals were excluded. Demographic data, clinical expression, iron parameters and HFE gene mutations (C282Y and H63D) were assessed in 222 patients. RESULTS: A total of 83.3% of patients were C282Y homozygous and 5% were compound heterozygous (C282Y/H63D). No significant differences in phenotypic expression or in the frequency of C282Y homozygosity were observed between patients born in the North and South of Spain. CONCLUSION: The genotypic and phenotypic expression of HH in Spain is very similar to that reported in Northern Europe. Thus, the genetic heterogeneity described in some Southern European regions cannot be considered a common feature to all countries of the Mediterranean Basin.

Female↗
PubMed2003

Cost-effectiveness analysis of therapeutic strategies for patients with chronic hepatitis C previously not responding to interferon.

BACKGROUND: The efficacy of combination therapy in patients with chronic hepatitis C previously not responding to interferon monotherapy is lower than that in naive patients, and there has been no economic evaluation in this population. AIM: To develop a cost-effectiveness analysis of therapeutic regimens with interferon-alpha and ribavirin in previous interferon non-responders. METHODS: A Markov simulation model was used to project the clinical and economic outcomes of five different therapeutic strategies, including a 'no treatment' alternative, using the health care system perspective. The efficacy data for the different doses and durations were obtained from a previously performed meta-analysis. A sensitivity analysis was performed to test the robustness of the model, analysing changes in different variables. RESULTS: Applying a 3% discount rate, the standard patient on combination therapy for 12 months showed increases of 0.80 years and 1.55 quality-adjusted life years, when compared with the 'no treatment' strategy. This option led to an incremental cost-effectiveness ratio of 11,767 euros per year of life gained and 6073 euros per quality-adjusted life year. CONCLUSIONS: Combination therapy with interferon plus ribavirin is cost-effective in previous interferon non-responders and is within the range of some well-accepted medical interventions in our health care system.

Adult↗
PubMed2003

A cost-effectiveness analysis of peginterferon alfa-2b plus ribavirin for the treatment of naive patients with chronic hepatitis C.

AIM: To estimate the cost-effectiveness of therapy and analyse the effect of therapy compliance in naive patients with chronic hepatitis C. METHODS: A decision analysis using the Markov model was performed for four different therapeutic strategies using peginterferon alfa-2b plus ribavirin or interferon alfa-2b plus ribavirin. Clinical data were obtained from available published reports and from the Spanish health system perspective. RESULTS: The incremental cost-effectiveness ratio of peginterferon alfa-2b plus ribavirin at a fixed dose, compared with interferon alfa-2b plus ribavirin, was 8478 euros per life year saved and 3737 euros per quality-adjusted life year gained. Good therapeutic compliance and weight-adjusted doses of ribavirin decreased the incremental cost-effectiveness ratio to 1636 euros per life year saved and 721 euros per quality-adjusted life year gained. In compliant genotype 1 patients, the incremental cost-effectiveness ratio decreased to 916 euros per life year saved and 404 euros per quality-adjusted life year gained, with an increase from 64 to 69 years in the threshold age at which therapy was cost-effective. The sensitivity analysis demonstrated that changes in the values of the most relevant parameters do not modify the study outcomes. CONCLUSION: From the clinical and pharmaco-economics perspective, the use of decision therapeutic analysis models suggests that the most effective therapy for chronic hepatitis C is peginterferon alfa-2b plus ribavirin adjusted to patient body weight and with good compliance, particularly in genotyped patients.

Adult↗
PubMed2002

[Study of hepatitis B virus replication and infection by other hepatitis viruses in patients with chronic hepatitis B virus infection].

AIM: To study hepatitis B virus (HBV) replication in a series of patients with HBV infection and to analyze the frequency of associated hepatitis C virus (HCV) and hepatitis D (HDV) infection. PATIENTS AND METHOD: Serological markers of HBV, HCV and HDV, transaminase values and HBV DNA were studied in serum samples from 463 patients with chronic HBV infection. RESULTS: Three hundred ninety-six (85.5%) were classified as hepatitis B, 33 (7.1%) as hepatitis B and C, 17 (3.6%) as hepatitis B and D and 17 (3.6%) as hepatitis B, C and D. Sixty-seven percent of patients with hepatitis B and 33% of those with chronic hepatitis B were asymptomatic HBsAg carriers. HVB DNA was identified in 27.7% of patients with hepatitis B, in 24% of those with hepatitis B and C, in 11.7% of those with hepatitis B and D and in 29.4% of those with hepatitis B, C and D. HBV DNA and elevated transaminase levels were found in 63% of HBeAg-positive patients and in only 16% of those who were anti-HBe-positive. These latter were considered candidates for antiviral treatment. CONCLUSIONS: In our environment, most patients with HBV infection are asymptomatic HBsAg carriers. Viral replication and elevated alanine aminotransferase levels were found in 22% of the patients. Consequently, these patients are candidates for antiviral treatment. Between 3.6% and 7.1% of patients with hepatitis B presented coinfection with HCV or HDV, or both. No significant differences were found in HBV replication among the different groups.

Adult↗
PubMed2002

Meta-analysis: combination therapy with interferon-alpha 2a/2b and ribavirin for patients with chronic hepatitis C previously non-responsive to interferon.

BACKGROUND: The efficacy of interferon-alpha plus ribavirin treatment for patients not responding to interferon monotherapy is not well established. AIM: To assess the efficacy and safety of combination therapy with interferon-alpha 2a/2b plus ribavirin by performing a meta-analysis of randomized clinical trials. METHODS: A systematic search of electronic databases for randomized clinical trials of interferon-alpha 2a/2b plus ribavirin was conducted independently by two investigators. Data abstraction was performed. The primary end-point was a sustained virological response. Estimates of the common odds ratio were calculated using a random effects model. RESULTS: Of the 127 identified studies, 46 were considered for evaluation and 10 were included (1728 patients). The pooled sustained virological response was 12.6% (95% CI, 9.5-16.3%) for combination therapy vs. 2% (95% CI, 0.9-4.0%) for interferon monotherapy, with a common odds ratio of 5.49. Higher doses of interferon, a longer duration of therapy (48 weeks) and genotypes other than 1 and 4 were associated with an improvement in response. More side-effects and discontinuations were observed with combination therapy than with interferon monotherapy. CONCLUSIONS: Non-responders to interferon may benefit from re-treatment with combination therapy, especially from a 48-week regimen.

Adult↗
PubMed2001

Quantitative hepatitis B virus DNA testing for the early prediction of the maintenance of response during lamivudine therapy in patients with chronic hepatitis B.

To determine whether a dramatic decrease in hepatitis B virus (HBV) DNA levels within the first months of lamivudine therapy can predict the emergence of YMDD variants in patients with chronic hepatitis B, quantitative testing was done every 3 months on serum samples from 35 patients who were treated with lamivudine for >1 year. The decline in HBV DNA levels from baseline to month 3 was higher in 22 responders than in 13 nonresponders (mean+/-SD, 4.16+/-1.06 vs. 2.88+/-1.77 log(10) copies; P=.002), whereas no differences were observed in patients with and without YMDD variants at 1 year of therapy. At 3 months, HBV DNA was undetectable in 77% of the responders, whereas, after 1 year, it was undetectable in 23% of nonresponders, 40% of patients with YMDD variants, and 74% of those without variants. Therefore, quantitative HBV DNA testing is very useful in deciding whether to continue therapy, because of the low likelihood of response in patients who remain HBV DNA positive at month 3 of treatment.

Adult↗
PubMed2001

[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.

Acute Disease↗