J. Guardia

Hepatitis C virus antibodies among risk groups in Spain.

The frequency of hepatitis C virus (HCV) infection in Spain was assessed by means of a recombinant-based immunoassay for serum anti-HCV antibodies. 836 serum samples were tested from 676 patients selected according to their risk of blood-borne viral infections and presence of liver disease. Among patients at high risk of infection (with or without liver disease) anti-HCV antibodies were found in 85% of prospectively followed patients with post-transfusion non-A, non-B hepatitis, 62% of patients with chronic hepatitis or cirrhosis and a history of blood transfusion, 70% of haemophiliacs receiving replacement therapy, 70% of intravenous drug abusers, and 20% of haemodialysis patients. Only 8% of homosexual men infected with human immunodeficiency virus and 6% of female contacts of drug abusers were positive. Among patients with liver disease and no history of parenteral exposure to blood, anti-HCV antibodies were detected in 38% with cryptogenic, alcoholic, or primary biliary cirrhosis and in 44% with chronic active hepatitis. Among healthy subjects without risk factors for hepatitis the overall prevalence of anti-HCV was 1.2%.

The development of low-grade cerebral edema in cirrhosis is supported by the evolution of 1H-magnetic resonance abnormalities after liver transplantation

BACKGROUND/AIMS Liver failure may cause brain edema through an increase in brain glutamine. However, usually standard neuroimaging techniques do not detect brain edema in cirrhosis. We assessed magnetization transfer ratio and (1)H-magnetic resonance (MR) spectroscopy before and after liver transplantation to investigate changes in brain water content in cirrhosis. METHODS Non-alcoholic cirrhotics without overt hepatic encephalopathy (n=24) underwent (1)H-MR of the brain and neuropsychological tests. (1)H-MR results were compared with those of healthy controls (n=10). In a subgroup of patients (n=11), the study was repeated after liver transplantation. RESULTS Cirrhotic patients showed a decrease in magnetization transfer ratio (31.5+/-3.1 vs. 37.1+/-1.1, P<0.01) and an increase in glutamine/glutamate signal (2.22+/-0.47 vs. 1.46+/-0.26, P<0.01). The increase in glutamine/glutamate signal was correlated to the decrease in magnetization transfer ratio and to neuropsychological function. Following liver transplantation, there was a progressive normalization of magnetization transfer ratio, glutamine/glutamate signal and neuropsychological function. Accordingly, correlations between these variables were lost after liver transplantation. CONCLUSIONS Cirrhotic patients show reversible changes in magnetization transfer ratio that are compatible with the development of low-grade cerebral edema. Minimal hepatic encephalopathy and low-grade cerebral edema appear to be the consequences of the metabolism of ammonia in the brain.

Quality of life and cognitive function in hepatitis C at different stages of liver disease

BACKGROUND/AIMS Hepatitis C has been associated with a decrease in quality of life and with neurological abnormalities. The aim of our study was to investigate the relationship between quality of life and cognitive function. METHODS Quality of life, clinical variables and neuropsychological function were evaluated in 120 patients with hepatitis C (mild chronic hepatitis, compensated cirrhosis and decompensated cirrhosis) and in healthy controls (n=40, in each group). RESULTS Patients with chronic hepatitis or compensated cirrhosis showed a decrease in quality of life, in spite of unimpaired neuropsychological tests. Patients with decompensated cirrhosis exhibited a further decrease in quality of life and neuropsychological abnormalities. The decrease in quality of life was associated with the severity of liver failure, neuropsychological abnormalities and treatment with beta-blockers or diuretics. However, in the multivariable analysis, only treatment with beta-blockers or diuretics (which was limited to decompensated cirrhosis) was independently associated with quality of life. CONCLUSIONS Hepatitis C causes a decrease in quality of life even in the absence of major cognitive impairment. The mechanisms that worsen quality of life are unknown. However, in cirrhotic outpatients with prior decompensations, treatment with beta-blockers or diuretics appears to have an important effect on quality of life.

Quantitative detection of hepatitis B virus DNA in serum by a new rapid real-time fluorescence PCR assay

A sensitive and accurate HBV DNA quantification assay is essential for monitoring hepatitis B virus (HBV) replication. This study evaluated a real‐time PCR method performed in the LightCyclerTM analyser for quantitative HBV DNA assay. HBV DNA results with this method were compared with those obtained using a branched‐chain DNA (bDNA) solution hybridization assay. Real‐time PCR was performed using two adjacent fluorescently labelled probes and primers corresponding to the HBV core gene. The same standard employed in the bDNA assay was used for calibration. Serum samples came from 193 HBV surface antigen (HBsAg)‐positive patients (34 HBV e antigen (HBeAg)‐positive and 93 with antibody to HBeAg (anti‐HBe)), and 66 asymptomatic HBV carriers. In addition, we analysed serum samples from 8 anti‐HBe‐positive patients who had been receiving lamivudine treatment for more than three years. A linear standard curve was seen in the range from 103 to 108 copies/mL. In the reproducibility analysis, intra‐assay coefficient of variation (CVs) at two known HBV DNA concentrations were 4% and 2% and interassay CVs were 6% and 4%. The median of serum HBV DNA by real‐time PCR was 9.2 × 108 copies/mL in HBeAg‐positive patients with persistently elevated alanine aminotransferase (ALT) levels, 1.3 × 107 copies/mL in anti‐HBe‐positive cases with persistently elevated ALT levels, 3.7 × 104 copies/mL in anti‐HBe‐positive patients with fluctuating ALT levels and 104 copies/mL in asymptomatic HBV carriers. The differences in HBV DNA levels among the various groups studied were statistically significant (P < 0.05). The cut‐off between chronic hepatitis patients and asymptomatic carriers was found to be at a serum HBV DNA concentration of 5 × 104 copies/mL. Of the 109 serum samples with a viral load < 7.5 × 105 (negative by bDNA assay) 44 (40%) were positive by real‐time PCR: 24 (56%) chronic hepatitis and 20 (33%) asymptomatic carriers. There was a positive association between HBV DNA levels determined by real‐time PCR and ALT levels (P < 0.05), which was not observed with the bDNA assay for HBV DNA quantification. At 12 months of lamivudine treatment, 6 patients (75%) showed HBV DNA levels < 5 × 104 copies/mL (range < 103–2 × 103), significantly lower than at baseline. At 36 months, 2 of 8 (25%) showed HBV DNA levels persistently lower than 5 × 104 copies/mL (1.7 × 103, 6 × 103). The LightCycler quantitative real‐time PCR is a practical, sensitive, reproducible single‐tube assay with a wide dynamic range of detection. The assay is automatic except for DNA extraction and the running time is only 70 min. The LightCycler real‐time PCR is useful for identifying different states of HBV infection and for evaluating the efficacy of viral therapy.

Development of a clinical hepatic encephalopathy staging scale.

To develop a scale to assess the severity of hepatic encephalopathy using simple dichotomic items.

Increased tumour necrosis factor α production in mesenteric lymph nodes of cirrhotic patients with ascites

Background: Cytokines produced in mesenteric lymph nodes of cirrhotic rats with bacterial translocation may participate in circulatory alterations of cirrhosis. Aim: To investigate whether cirrhotic patients present an increased local generation of cytokines in mesenteric lymph nodes. Methods: Mesenteric lymph nodes from 26 cirrhotic and 10 control patients were assessed for tumour necrosis factor α (TNF) and interleukin 6 mRNA and protein expression by competitive reverse transcription-polymerase chain reaction, and by enzyme immunoassay and immunohistochemistry, respectively. Results: Interleukin 6 levels were not different between cirrhotics and controls. Protein and mRNA TNF levels in mesenteric lymph nodes from cirrhotics were higher than in controls (p<0.05). Tissue expression of TNF by immunohistochemistry was more abundant in cirrhotics. Ascitic patients showed higher TNF levels (47 (34–54) pg/mg protein) than patients without ascites (18 (17–25) pg/mg protein) (p<0.001). Elevated TNF levels (>28 pg/mg protein) in cirrhotics were associated with a higher Child-Pugh score, the antecedent of ascites, a lower prothrombin rate, and higher bilirubin and blood TNF levels. The strongest association, confirmed by multivariate analysis, was with the presence of ascites (p<0.001). Bacterial infections after transplantation, mainly by enteric bacteria, were only detected in patients with high TNF levels in mesenteric lymph nodes (33% of patients; p=0.05). Conclusion: Patients with advanced liver cirrhosis, and especially with ascites, have increased local production of TNF in mesenteric lymph nodes that, in common with experimental cirrhosis, may also be induced by bacterial translocation.

Peginterferon alpha-2b plus ribavirin vs interferon alpha-2b plus ribavirin for chronic hepatitis C in HIV-coinfected patients

Summary.  Treatment of chronic hepatitis C in human immunodeficiency virus (HIV)‐infected patients is associated with low response rates and high incidence of side effects. One hundred twenty‐one hepatitis C virus (HCV)–HIV‐coinfected patients were randomized to receive interferon alpha‐2b (3 MU thrice weekly; n = 61) or peginterferon alpha‐2b (1.5 μg/kg/week; n = 60), plus ribavirin (800 mg daily), for 24 (genotype 2 or 3) or 48 weeks (genotype 1 or 4). We assessed early virological response at 4, 8 and 12 weeks to predict sustained virological response (SVR). Safety assessment included frequent blood lactate measurement and relative quantitation of mitochondrial DNA (mtDNA) content in peripheral blood mononuclear cells. In intention‐to‐treat analysis, the SVR rate was higher in the peginterferon group (55%vs 26%; P = 0.002). The difference for HCV genotypes 1 and 4 was 45%vs 14% (P = 0.009) and 50%vs 27% (P = 0.387), respectively, and for genotype 2 or 3, 71%vs 43% (P = 0.12) Viral response at 4, 8 and 12 weeks of treatment was highly predictive of SVR. Among genotype 3 patients, 17 of 20 (85%) whose HCV RNA was already undetectable at 4 weeks had an SVR after 24 weeks of treatment. Hyperlactataemia occurred in 22 patients and was clinically significant in six, two of whom died. mtDNA decreased significantly 4–12 weeks after the start of treatment in patients developing clinically significant hyperlactataemia. Peginterferon alpha‐2b plus ribavirin was more effective than interferon alpha‐2b plus ribavirin in HIV‐coinfected patients. Frequent monitoring of virological response may be very helpful to optimize treatment compliance, to tailor treatment duration and to minimize side effects.

Ultra-Deep Pyrosequencing (UDPS) Data Treatment to Study Amplicon HCV Minor Variants

We have investigated the reliability and reproducibility of HCV viral quasispecies quantification by ultra-deep pyrosequencing (UDPS) methods. Our study has been divided in two parts. First of all, by UDPS sequencing of clone mixes samples we have established the global noise level of UDPS and fine tuned a data treatment workflow previously optimized for HBV sequence analysis. Secondly, we have studied the reproducibility of the methodology by comparing 5 amplicons from two patient samples on three massive sequencing platforms (FLX+, FLX and Junior) after applying the error filters developed from the clonal/control study. After noise filtering the UDPS results, the three replicates showed the same 12 polymorphic sites above 0.7%, with a mean CV of 4.86%. Two polymorphic sites below 0.6% were identified by two replicates and one replicate respectively. A total of 25, 23 and 26 haplotypes were detected by GS-Junior, GS-FLX and GS-FLX+. The observed CVs for the normalized Shannon entropy (Sn), the mutation frequency (Mf), and the nucleotidic diversity (Pi) were 1.46%, 3.96% and 3.78%. The mean absolute difference in the two patients (5 amplicons each), in the GS-FLX and GS-FLX+, were 1.46%, 3.96% and 3.78% for Sn, Mf and Pi. No false polymorphic site was observed above 0.5%. Our results indicate that UDPS is an optimal alternative to molecular cloning for quantitative study of HCV viral quasispecies populations, both in complexity and composition. We propose an UDPS data treatment workflow for amplicons from the RNA viral quasispecies which, at a sequencing depth of at least 10,000 reads per strand, enables to obtain sequences and frequencies of consensus haplotypes above 0.5% abundance with no erroneous mutations, with high confidence, resistant mutants as minor variants at the level of 1%, with high confidence that variants are not missed, and highly confident measures of quasispecies complexity.

Ultra-Deep Pyrosequencing Detects Conserved Genomic Sites and Quantifies Linkage of Drug-Resistant Amino Acid Changes in the Hepatitis B Virus Genome

Background Selection of amino acid substitutions associated with resistance to nucleos(t)ide-analog (NA) therapy in the hepatitis B virus (HBV) reverse transcriptase (RT) and their combination in a single viral genome complicates treatment of chronic HBV infection and may affect the overlapping surface coding region. In this study, the variability of an overlapping polymerase-surface region, critical for NA resistance, is investigated before treatment and under antiviral therapy, with assessment of NA-resistant amino acid changes simultaneously occurring in the same genome (linkage analysis) and their influence on the surface coding region. Methodology/Principal Findings Serum samples obtained from chronic HBV-infected patients at pre-treatment and during sequential NA treatment with lamivudine, adefovir, and entecavir were analyzed by ultra-deep pyrosequencing (UDPS) using the GS-FLX platform (454 Life Sciences-Roche). The pre-treatment HBV quasispecies was not enriched with NA-resistant substitutions. The frequencies of this type of substitutions at pre-treatment did not predict the frequencies observed during lamivudine treatment. On linkage analysis of the RT region studied, NA-resistant HBV variants (except for rtA181T) were present in combinations of amino acid substitutions that increased in complexity after viral breakthrough to entecavir, at which time the combined variant rtL180M-S202G-M204V-V207I predominated. In the overlapping surface region, NA-resistant substitutions caused selection of stop codons in a significant percentage of sequences both at pre-treatment and during sequential treatment; the rtA181T substitution, related to sW172stop, predominated during treatment with lamivudine and adefovir. A highly conserved RT residue (rtL155), even more conserved than the essential residues in the RT catalytic motif YMDD, was identified in all samples. Conclusions UDPS methodology enabled quantification of HBV quasispecies variants, even those harboring complex combinations of amino acid changes. The high percentage of potentially defective genomes, especially in the surface region, suggests effective trans-complementation of these variants.

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

Summary.  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.