HCV drug discovery aimed at viral eradication.

Hepatitis C virus (HCV) causes significant morbidity and mortality worldwide with nearly 3% of the world population infected by this virus. Fortunately, this virus does not establish latency, and hence it may be possible to eradicate it. HCV is strongly associated with liver cirrhosis and hepatocellular carcinoma and is currently treated with pegylated interferon-alpha (peg-IFN-alpha) and ribavirin. Unfortunately, these limited treatment options often produce significant side effects, and currently, complete eradication of virus with combined drug modalities has not yet been achieved for the majority of chronically HCV-infected individuals. Restricted treatment options, lack of a universal cure for HCV and the link between chronic infection, liver cirrhosis and hepatocellular carcinoma necessitate design of novel drugs and treatment options. Understanding the relationship between the immune response, viral clearance and inhibition of viral replication with pharmacology-based design can ultimately allow for complete eradication of HCV. This review focuses upon significant novel preclinical and clinical specifically targeted antiviral therapy (STAT-C) drugs under development, highlights their mechanism of action, and discusses their impact on systemic viral loads and permanent clearance of infection.

Prevalence of GB virus C (hepatitis G virus) and risk factors for infection in São Paulo, Brazil.

The prevalence of GB virus C (GBV-C) varies widely throughout the world. A cross-sectional study was conducted in the city of São Paulo, Brazil, to estimate the prevalence of GBV-C infection and to identify associated risk factors, using a large sampling of the general population rather than blood donors or an illness-related group of subjects. GBV-C RNA was detected by reverse-transcriptase polymerase chain reaction using primers directed to the 5' noncoding region (NCR) and nonstructural 5A region (NS5A) in serum samples from 1,039 healthy individuals 2 years of age or more. Fifty-two individuals were positive for both sets of primers and one was positive for NS5A only (prevalence of GBV-C infection, 5.1%; 95%CI, 3.9-6.7%). No child under 5 years of age was found positive. Among subjects aged 5 years or more, the prevalence of infection increased consistently with age, up to 30-39 years (8.3%), and decreased from then on. The number of sexual partners in the last 3 years (2 or more: OR, 2.6; 95%CI, 1.3-5.5) and history of contact with blood-sucking insects (OR, 2.5; 95%CI 1.2-5.4) were independently associated with GBV-C infection. In conclusion, the prevalence of GBV-C infection is high in São Paulo. In addition to parenteral transmission, another route, e.g. sexual or vertical, may be involved.

Chronic hepatitis C virus infections in brazilian patients: association with genotypes, clinical parameters and response to long term alpha interferon therapy

The present study assessed the clinical significance of hepatitis C virus (HCV) genotypes and their influence on response to long term recombinant-interferon-alpha (r-IFN-alpha) therapy in Brazilian patients. One hundred and thirty samples from patients previously genotyped for the HCV and with histologically confirmed chronic hepatitis C (CH-C) were evaluated for clinical and epidemiological parameters (sex, age, time of HCV infection and transmission routes). No difference in disease activity, sex, age or mode and time of transmission were seen among patients infected with HCV types 1, 2 or 3. One hundred and thirteen of them were treated with 3 million units of r-IFN-alpha, 3 times a week for 12 months. Initial response (IR) was significantly better in patients with genotype 2 (100%) and 3 (46%) infections than in patients with genotype 1 (29%) (p < 0. 005). Among subtypes, difference in IR was observed between 1b and 2 (p < 0.005), and between 1b and 3a (p < 0.05). Sustained response (SR) was observed in 12% for (sub)type 1a, 13% for 1b, 19% for 3a, and 40% for type 2; significant differences were found between 1b and 2 (p < 0.001), and between 1b and 3a (p < 0.05). Moreover, presence of cirrhosis was significantly associated with non response and response with relapse (p < 0.05). In conclusion, non-1 HCV genotype and lack of histological diagnosis of cirrhosis were the only baseline features associated with sustained response to treatment. These data indicate that HCV genotyping may have prognostic relevance in the responsiveness to r-IFN-alpha therapy in Brazilian patients with chronic HCV infection, as seen in other reports worldwide.

Hepatitis G virus: prevalence and sequence analysis in blood donors of São Paulo, Brazil.

BACKGROUND AND OBJECTIVES: Hepatitis G virus (HGV) is a recently discovered viral agent transmitted by blood, which was firstly identified in patients with acute or chronic liver disease. HGV prevalence in US blood donors was recently found to average 1-2%. We report a much higher HGV frequency among blood donors of São Paulo, Brazil. MATERIALS AND METHODS: 200 serum samples were submitted to RT-PCR using primers directed to the 5' untranslated region and nonstructural 5A (NS5A) region. PCR products were analyzed by gel electrophoresis and Southern blot hybridization. RESULTS: Of the 200 specimens, 18 (9%; 95% CI 5.4-13.8%) were positive by both sets of primers. Sequence analysis of the NS5A PCR products revealed a homology of 96.3%. Of the 18 HGV-positive samples, only one was positive for anti-HBc and all were anti-HCV- and HCV-RNA-negative. CONCLUSION: Such a high prevalence of HGV in a nonsymptomatic population suggests that this is a benign agent.

Estimated Prevalence of Viral Hepatitis in the General Population of the Municipality of São Paulo, Measured by a Serologic Survey of a Stratified, Randomized and Residence-Based Population.

The present study was done to estimate the prevalence of Hepatitis A (HAV), B (HBV), C (HCV), and E (HEV) infection in the general population residing in the municipality of São Paulo, and to evaluate the level of knowledge related to the various modes of infection transmission by and protection against the different viruses. Blood samples and health questionnaires were collected from 1,059 individuals. The study design used an inductive method of predictive statistical inferences through randomized sampling stratified by Sex, age and residence region. The estimated prevalence rated found were: Hepatitis A = 66.59% (63.75%-69.44% CI); Hepatitis B = 5.94% (4.50%-7.35%); Hepatitis C = 1.42% (0,70%-2.12%); Hepatitis E = 1.68% (0.91%-2.46%). The frequency of hepatitis was similar in males and females. HAV showed an estimated prevalence of 56.16% in the population up to 17 years old, increasing to 65.30% in individuals between 18 and 29 years. The infection reached its peak of 90% in individuals 40 years of age or older. The study showed a greater tendency of dissemination of HBV among the population between 15 and 17 years. This specific age group showed an estimated prevalence of active infection of 1.04% (0.43%-1.65% CI), and also demonstrated an ascending level of acquired immunity with an estimated prevalence of 4.90% (3.60%-6.20% CI). HCV demonstrated an estimated prevalence of 1.42% (0.70%-2.12% CI). This specific infection occurred more frequently among adults 30 years of age or older, with the prevalence reaching a peak of 3.80% among the group aged 50 to 59 years. HEV showed zero prevalence among the age group between 2 and 9 years. This was followed by a slightly ascending rate starting from age 10, with an estimated prevalence of 1.05% (0.94%-3.04% CI) among those 10 to 14 years of age. This infection reached its peak of 3.00% (0.55%-6.74% CI) at the age of 60 years or older. Individuals with lower educational levels had a higher tendency of acquiring HAV and HCV, while there was no statistically significant difference for this parameter related to HBV and HEV. HBV occurred more frequently among inhabitants of the northern region of the city. All other hepatitis forms occurred at similar frequencies among the five regions of the city. Among the population, 1.90% (1.08%-2.72% CI) demonstrated an elevated hepatic enzyme with no serologic evidence indicating the cause was the viruses studied. This observation suggests the presence of other hepatic diseases, possibly including other viral diseases. It was also estimated that 75.12% of the city's population did not know the modes of transmission of hepatitis viruses and 76.70% did not know how to prevent them. This clearly suggests the need for a full-scale education program combined with public health measures regarding prevention of all forms of vial hepatitis.

Spontaneous hepatitis B surface antigen clearance in a long-term follow-up study of patients with chronic type B hepatitis. Lack of correlation with hepatitis C and D virus superinfection.

We investigated the frequency of HBsAg clearance and the possible role of viral superinfection in a long-term follow-up of 184 patients with chronic hepatitis B (CHB). Our subjects were 184 patients with chronic hepatitis B and the follow-up was 12-216 months (mean 66.2 +/- 53.7 months). The investigative methods used were: immunoenzymatic assays for HBV, HCV, HDV, and HIV markers; polymerase chain reaction (PCR) for HBV DNA; and liver biopsy and immunoperoxidase. During the follow-up, 20 of the 184 patients cleared serum HBsAg. A comparison of patients with persistent HBsAg(group I) and of those who cleared this marker (group II) showed a significant difference in mortality (P = 0.002) between the two groups and a tendency to a more severe exacerbation (flare) in group II (P = 0.07). Antibodies to hepatitis C and D virus as well as antibodies to HIV were equally distributed in both groups. Thirteen patients (7.9%) from group I, but none from group II, subsequently developed hepatocellular carcinoma. These results suggest that the frequency of spontaneous clearance of HBsAg during chronic HBV infection is low. No determinant factor for the clearance was found, including the presence of liver cirrhosis. Serum HBV DNA was undetectable by PCR after clearance in 16 out of 17 patients.

Hepatitis C virus genotyping by means of 5'-UR/core line probe assays and molecular analysis of untypeable samples.

To test the theoretical possibility of 5'-UR mistyping between hepatitis C virus subtypes 1a and 1b, we combined a 5'-UR/Core line probe assay (LiPA) with a nested PCR system and retested 183 sera, previously genotyped as type 1a or 1b and originating mainly from Western Europe. Eight percent of these were found to be wrongly subtyped. Based on this method, 3 additional subtypes of type 1 were discovered (1d-1f). Randomly selected European type 2 sera (n = 18) were tested with a similar type 2 5'-UR/Core LiPA. They were unexpectedly found to belong to subtype 2c in the majority of cases. Among serum samples originating from South-East Asia, several additional genotypes (7a, 7c, 7d, and 9a) were detected which had 5'-UR sequence motifs indistinguishable from genotype 1. Based on 13,203 pairwise comparisons in the 340-bp NS5B region, classification into types, subtypes, and isolates was obtained in 99.8% of all cases by using the phylogenetic border value of 0.328 for subtypes/types and 0.127 for isolates/subtypes; and evidence for a 10th major type of HCV was provided. Combination of all available HCV sequence data from the 447-bp Core/E1 region and the NS5B 340-bp and 222-bp regions provided evidence for the existence of 10 types, including 50 subtypes. Previously, extensive studies involving genotypes 1a, 1b, 2a, and 2b indicated the importance of HCV subtyping in interferon treatment and progression of chronic liver disease. The herein described expansion in the number of HCV types and subtypes should help improve diagnosis, treatment and possibly prophylaxis of hepatitis C liver disease.

Human T lymphotropic virus type I-associated myelopathy/tropical spastic paraparesis in São Paulo, Brazil.

We conducted a prospective clinical and epidemiologic evaluation of 45 cases of human T lymphotropic virus type I (HTLV-1)-associated myelopathy/tropical spastic paraparesis (HAM/TSP) in São Paulo, Brazil. All enrolled patients had progressive chronic myelopathy and high titers of HTLV-I and HTLV-II antibodies, as determined by enzyme immunoassay and western blot. In 24 cases, the polymerase chain reaction (PCR) was performed so that HTLV-I could be distinguished from HLTV-II. The clinical and epidemiologic features of the patients from our study were similar to those of patients with HAM/TSP from other areas of endemicity for HTLV-I except that more patients in our study had received a blood transfusion prior to their illness. Despite the presence of HTLV-II virus in Brazil, all patients whose serum was tested by PCR were found to be infected with the HTLV-I virus.

Prevalência de anticorpos anti-HTLVI/II em doadores de sangue da Fundaçäo Pró-Sangue Hemocentro de Säo Paulo / Prevalence of anti-HTLVI/II antibodies in blood donors of Fundaçäo Pró-Sangue Hemocentro de Säo Paulo

O teste ELISA ant-HTLVI/II foi introduzido na triagem sorlógica de doadores de sangue na Fundaçäo Pró-sangue Hemocentro de Säo Paulo (FPS/HSP) em julho de 1991. NO período compreendido entre julho de 1991 e julho de 1994 foram submetidos à triagem serológica 597.727 doadores. Destes, 7682 foram recusados por terem apresentado reatividade no teste ELISA anti-HTLVI/II. A positividade observada, para o referido teste, foi diminuindo com o correr do tempo: 2,12 por cento em 1991; 1,6 por cento em 1992; 0,8 por cento em 1993 e 1,0 por cento em 1994, sendo esse fato atribuido a melhora da especialidade e reprodutividade dos kits comerciais. Foi utilizado o teste suplementar de Western Blot para confirmar os resultados dos testes ELISA. Em 249 amostras de soros de doadores, com resultado repetidamente positivo (RRP) no teste ELISA (hemobio), o poder confirmatório do Western Blot (Cambridge Biotech) foi de 24.9 por cento (IC/90 por cento: 20,4 por cento-29,39 por cento). Baseados nesses dados, considera-se uma expectativa de prevalência de indivíduos infectados pelo HTLVI/II, na populaçäo de doadores de sangue da FPS/HSP de 0,142 por cento (IC/90 por cento; 0,116 por cento-0,167 por cento). Em 437 amostras de soro de doadores que retornaram ao Banco de Sangue, para confirmar o resultado inicial e apresentaram RRP no teste ELISA, o poder confirmatório do Western Blot foi de 34,55 por cento (IC/90 por cento: 30,82 por cento-38,28 por cento)...

Detection of hepatitis B virus DNA by the polymerase chain reaction in anti-HBe positive chronic hepatitis B patients.

Detection of HBV-DNA by PCR was compared with other serological markers (HBsAG, HBeAg and anti-HBe) in a series of 49 Chronic Hepatitis B patients, including 12 with a spontaneous clearance of HBsAg. None of these HBsAg negative cases were PCR positive, but 33/37 (89.2%) HBsAg positive cases were PCR positive (p < 0.0001). Among HBsAg positive samples, nine cases were HBeAg positive and anti-HBe negative, all of them PCR positive. Other 3 patients were HBeAg and anti-HBe positive and these cases were also found PCR positive. A third group included 21 patients anti-HBe positive and HBeAg negative: 19 of them were PCR positive and 2 were PCR negative. The last 4 cases were HBeAg and anti-HBe negative, two of them were PCR positive. The detection of anti-HBe viremic cases in the present series suggest that preC variants could occur in our country. In conclusion, the integrated phase of chronic hepatitis B seems to be less frequent than it was assumed, when only HBeAg or dot blot hybridization techniques were used. The new term "low replication phase" might favorably replace the former "integrated phase".

Catarata secundária a hipoparatreoidismo / Cataract secondary to hypoparathyroidism

O hipoparatireoidismo, condiçäo em que há produçäo insuficiente de hormônio paratireóideo (PTH), provoca distúrbio metabólico caracterizado por hipocalcemia e hiperfosfatemia e suas consequentes mainifestaçöes clínicas. A manifestaçäo ocular principal do hipoparatireoidismo constitui a formaçäo da catarata. A gênesi da catarata no hipoparatireoidismo parece estar ligada ao desequilíbrio iônico no cristalino causado pela hipocalcemia. Apresentamos um caso de catarata bilateral, secundária a hipoparatireoidismo pós-cirúrgico, em paciente de 61 anos