J.I. Esteban

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%.

epidemiology of hepatitis C virus infection in seven European Union countries: a critical analysis of the literature

Hepatitis C is now recognized as the most common infection causing chronic liver disease in the European population. Our aim was to assess the prevalence of the antibody to hepatitis C virus (HCV), and the incidence of HCV seroconversion in the general population and the main risk groups, namely intravenous drug users, haemodialysis and transfused patients, in seven countries of the European Union, by carrying out a critical analysis of the literature. Data sources used were the Medline database and a manual search using the key words: hepatitis C, prevalence, incidence, transmission, risk factors and epidemiology. Articles published between January 1990 and March 1997 were reviewed. Articles were reviewed according to a critical analysis method regarding title, type of article, study design, period and population, tests, results and their consistency with data. The tests performed were mainly second- or third-generation serological tests. The average prevalence rate in blood donors was 1%, with a north-south gradient ranging from 0.04% to 2%. Prevalence varied from 20% to 30% in haemodialysis patients. The incidence in transfused patients was less than 1% after 1991. The prevalence in intravenous drug users was about 80%. Multicentre studies conducted in larger samples are needed to obtain more accurate and reliable results, in particular. However, the epidemiological studies available allowed us to assess the magnitude of HCV infection in Europe.Eur J Gastroenterol Hepatol12:667-678

Hepatitis C viral quasispecies.

Analysing significant numbers of cDNA clones of the hepatitis C virus (HCV) from single isolates provides unquestionable proof that the viral genome cannot be defined by a single sequence, but rather by a population of variant sequences closely related to one another. This way of organizing the genetic information is referred to as quasispecies. Throughout HCV infection, the number and composition of the variants in the viral population keeps changing owing to environmental influences, resulting in a virus that is constantly redefining itself both genetically and phenotypically. Therefore, the virus has often been investigated in population terms. Many clinical studies have tried to unravel, through the parameters that characterize the HCV quasispecies, prognostic markers of the disease and its response to treatment. Other investigations have focused on discovering how the virus and host interact during chronic infection. The consensus sequence, the rate of fixation of mutations and the complexity of the viral population are useful parameters for describing the viral population behaviour and its interaction with the host. In addition to sequencing, several other methods, based on electrophoretic mobility, have been used to study these parameters, such as temperature gradient‐gel electrophoresis, single‐strand conformation polymorphism and gel‐shift analysis. The viral region examined, the source of clinical specimen, as well as the methodology employed, will be decisive in interpreting the information obtained.

Long-term follow-up of the hepatitis C HENCORE cohort: response to therapy and occurrence of liver-related complications

Summary.  The aims of the study were to verify the long‐term effect of time on viral clearance in hepatitis C virus (HCV) patients and to find out factors possibly associated with disease progression. A total of 1641 patients recruited from eight European centres in 1996–1997 were re‐analysed 5–7 years after inclusion. The occurrence of decompensated cirrhosis, hepatocellular carcinoma (HCC) and liver transplantation was analysed in relation to different host and viral factors. Ninety‐three per cent of the HCV patients who had cleared the virus (spontaneously or after antiviral therapy) remained HCV‐RNA‐negative during follow up and may be considered as ‘cured’. Among patients who were sustained responders at inclusion, 2.3% developed liver complications during follow up, and 31% of non‐responders did. Advanced age at infection and presence of the human leucocyte antigen (HLA) DRB1*1201–3 allele were possibly associated with a higher rate of progression to decompensated cirrhosis or HCC. Decompensated cirrhosis might be further associated with male gender, non‐response to previous therapy, and lack of HLA DRB1*1301 allele, whereas HCC seems to be associated with the presence of the HLA DQ02 allele. Long‐term follow up of HCV patients indicates that virological response persists over time and is associated with a very low incidence of liver complications. Advanced age at inclusion, advanced age at infection, viral genotype 1, non‐response to previous therapy and possibly some specific HLA alleles are factors independently associated with a faster rate of progression towards liver complications. The large proportion of patients lost to follow up stresses the need for a strengthened and optimized management of HCV patients.

Hepatitis E virus infection in acute hepatitis in Spain.

In order to study the prevalence of hepatitis E virus (HEV) infection in developed countries, IgG and IgM anti-HEV were determined in serum samples from 382 patients with acute viral hepatitis (244 hepatitis A, 48 hepatitis B and/or D, and 90 non-A, non-B, non-C hepatitis), 76 healthy subjects, 55 hemophiliacs and 50 patients on hemodialysis. IgG anti-HEV antibodies were detected and confirmed by a synthetic peptide-based EIA in 5 (5.6%) non-A, non-B, non-C acute hepatitis, in 3 (6.5%) B and D acute hepatitis, in 10 (4%) acute A hepatitis, in 3 (5.5%) of 54 healthy adults in none of the hemophiliacs and in 3 (6%) patients on hemodialysis. IgM anti-HEV antibodies were only detected in two cases of acute hepatitis B and/or D. Analysis of serial serum samples demonstrated IgG anti-HEV seroconversion in 3 of the 18 confirmed cases; one of them was also positive for IgM anti-HEV. All 3 acute anti-HEV-positive hepatitis cases occurred in adults, were community-acquired (two of them were intravenous drug addicts) and had a self-limited course. These results demonstrate that HEV is a minor cause of acute hepatitis in Spain. A similar low rate of IgG anti-HEV antibodies was detected in patients with different diseases, suggesting that HEV has a very low epidemiological impact. An apparent association of HEV infection with hepatitis B and D suggests a possible parenteral transmission of a mainly enteral pathogen.

Early detection of nonresponse to interferon plus ribavirin combination treatment of chronic hepatitis C

We have investigated the value of early hepatitis C virus (HCV) RNA decline (ΔHCV RNA) to predict response to combination therapy in 66 chronic hepatitis C patients treated with IFN‐α2b (3 MU thrice weekly) and ribavirin (800 mg daily) for 12 months [25 sustained responders (SR) and 41 nonresponders or relapsers (NR)]. Serum HCV RNA was retrospectively measured in samples obtained at baseline and 4, 8 and 12 weeks after treatment onset, using a commercially available quantitative RT‐PCR assay. At 4 weeks, serum HCV RNA had decreased a mean of 2.6 ± 0.8 logs among SR as compared with only 0.5 ± 0.8 logs in NR (P < 0.001), and was already undetectable (< 600 IU/mL) in 12 (48%) of the SR but in none of the NR. At 8 weeks, HCV RNA was undetectable in 21 SR and in 2 NR and mean ΔHCV RNA were 4.2 ± 1.3 and 0.8 ± 1.0 logs, respectively (P < 0.001). At week 12 all SR had undetectable HCV RNA as compared with only five NR (P < 0.001). Stepwise logistic regression analysis identified ΔHCV RNA at 12 weeks as the strongest predictor of sustained response. Receiver operating characteristic (ROC) curves of ΔHCV RNA for sustained response prediction identified sensitivity peaks with 100% negative predictive value corresponding to ΔHCV RNA > 1 log at 4 weeks, > 2 logs at 8 weeks and > 3 logs at 12 weeks. Our results show that early changes in the HCV RNA level may reliably identify patients having no chance of a sustained virological response during the first 3 months of combination therapy, thus providing an excellent tool for optimizing antiviral treatment of chronic hepatitis C.

Anti-HD IgM as a marker of chronic delta infection.

The value of anti-HD IgM as a marker of chronic delta infection was evaluated by correlating its presence in serum with that of HD-Ag in liver cells and with the degree of inflammatory activity. Thirty-six patients with HBsAg-positive chronic hepatitis and anti-HD at high titers were studied. Overall, the liver cells of 26 patients contained HD-Ag and 27 were positive for IgM anti-HD. The correlation between both markers was excellent: 25 cases were positive for both serum anti-HD IgM and intrahepatic HD-Ag and 8 were negative for both markers. There was only 1 HD-Ag-positive patient, who was anti-HD IgM-negative. Two patients were anti-HD IgM-positive and HD-Ag-negative. Histological damage was more severe in anti-HD IgM-positive cases than in those negative for this marker (Knodells index 13.5 vs 11.9, P less than 0.01). We conclude that anti-HD IgM is a good marker of chronic active delta infection.

Nosocomial transmission of hepatitis C virus during contrast-enhanced computed tomography scanning.

We have investigated two cases of acute hepatitis C that occurred in patients who underwent digestive endoscopy and contrast-enhanced computed tomography (CT) scanning at two different centers. Investigations to identify the sources of infection included an on-site review of diagnostic procedures, interview of the involved healthcare staff, serological testing of the patients who underwent the procedures before and after the index cases and a molecular analysis of viral isolates from the patients and from potential viremic sources. In both cases, the epidemiological investigation identified a chronic hepatitis C virus (HCV) carrier who had been subjected to CT-scanning immediately before the index patient. Genetic distance and molecular phylogenetic analyzes of HCV sequences showed a close relationship between the isolates from these carriers and those from the acute-hepatitis patients, strongly suggesting that patient-to-patient transmission had occurred during CT. This is the first report describing two well documented cases of HCV nosocomial patient-to-patient transmission during contrast-enhanced CT scanning.

Clinical and serological outcome of acute delta infection

To assess the clinical and serological outcome of hepatitis delta virus (HDV) infection, 59 patients with acute delta hepatitis were followed for 6-28 months. Forty-two patients had simultaneous HDV and HBV coinfection (anti-HBc IgM-positive, group I) and 17 were HBsAg carriers with HDV superinfection (anti-HBc IgM-negative, group II). Overall, serum HD-Ag and anti-HD IgM were the most sensitive markers for diagnosis of delta infection during the first 2 weeks after onset of symptoms. The clinical presentation was similar in both groups; 4 patients (1 in group I and 3 in group II) (7%) developed fulminant hepatitis, but none of them died. The majority of patients with HBV-HDV coinfection (group I) eventually recovered, whereas all HBsAg carriers with HDV superinfection (group II) developed chronic liver disease. Liver histology in these patients showed chronic active hepatitis and/or cirrhosis in 90%. The hepatic lesion was probably due to persistent HDV infection, as indicated by the presence of intrahepatic HD-Ag and/or persistence of serum anti-HD IgM in 90% of the patients.

Subtype mutations in the envelope 2 region including phosphorylation homology domain of Hepatitis C virus do not predict effectiveness of antiviral therapy

Summary.  The aim of this study was to determine whether specific sequences of the phosphorylation homology domain (PePHD) region could be correlated with differences in response to antiviral therapy in patients infected with hepatitis C virus subtypes 1b, 2c, 3a and 4c/d. We included 43 patients (22 sustained responders and 21 nonresponders or relapsers) in the study, who were classified according to early viral decline during the first weeks of antiviral treatment and response at end of follow up. Type of mutations, mutation frequency, genetic diversity and phylogenetic relationships were compared at the PePHD and flanking regions. Phylogenetic trees showed that each sequence clustered together with those of the same subtype. Sequences from subtypes 1b and 4c/d resembled more closely the phosphorylation sites of protein kinase R and eIF2α than sequences from genotypes 2c and 3a, the latter with higher response rates to interferon‐α (IFNα) treatment. However, within specific subtypes, no separate clusters of responders and nonresponders were observed either at the beginning or at the end of follow up. We were not able to find any particular sequence or mutation in the PePHD region or in any other subregion of the fragment studied that allowed prediction of treatment response.