[Show abstract][Hide abstract] ABSTRACT: The anti-HCV antibody response has not been well characterized during the early phase of HCV infection and little is known about its relationship to the clinical course during this period.
We analyzed serial anti-HCV antibodies longitudinally obtained from a prospective cohort of 65 patients with acute HCV infection by using a microparticle enzyme immunoassay AxSYM HCV 3.0 (Abbott Diagnostics) during the first 12 months from HCV acquisition in Rio de Janeiro, Brazil. Spontaneous viral clearance (SVC) was defined as undetectable HCV RNA in serum, in the absence of treatment, for three consecutive HCV PCR tests within 12-months of follow-up.
Baseline antibody values were similar among patient groups with self-limiting HCV evolution (n = 34) and persistent viremia (n = 31) [median (interquartile range) signal/cut-off ratio (s/co) 78.7 (60.7-93.8) vs. 93.9 (67.8-111.9), p = 0.26]. During 12-months follow-up, patients with acute spontaneous resolving HCV infection showed significantly lower serial antibody response in comparison to individuals progressing to chronic infection [median (interquartile range) s/co 62.7 (35.2-85.0) vs. 98.4 (70.4-127.4), p < 0.0001]. In addition, patients with self-limiting HCV evolution exhibited an expeditious, sharp decline of serial antibody values after SVC in comparison to those measured before SVC [median (interquartile range) s/co 56.0 (25.4-79.3) vs. 79.4 (66.3-103.0), p < 0.0001].
Our findings indicate a rapid short-term decline of antibody values in patients with acute spontaneous resolving HCV infection.
Full-text · Article · Jan 2011 · BMC Infectious Diseases
[Show abstract][Hide abstract] ABSTRACT: In the last decade, a declining prevalence of HCV infection has been described in injecting drug users (IDUs) in different countries. This study is the first to assess temporal trends in drug-injecting patterns, HCV infection rates and viral genotype distribution in 770 Brazilian IDUs, recruited by two cross-sectional studies (1994-1997 and 1999-2001). A substantial decline in the prevalence of HCV infection was found over the years (75% in 1994 vs. 20.6% in 2001, P<0.001) that may be a consequence of the significant reduction in the overall frequencies of drug injection and needle-sharing, as well as the participation of IDUs in initiatives aimed at reducing drug-related harm. No trend was found in terms of viral genotype distribution. Despite the favourable scenario, preventive measures must be maintained, especially in vulnerable subgroups such as young or new injectors, where risky behaviours through direct and indirect sharing practices remain common.
Full-text · Article · Jul 2009 · Epidemiology and Infection
[Show abstract][Hide abstract] ABSTRACT: Since the identification of hepatitis C virus (HCV) in 1989 as a causative agent for a number of the extrahepatic alterations related to HCV infection an underlying immune mediated pathogenetic mechanism has been postulated. HCV-associated thrombocytopenia may be considered complex and multifactorial in origin, since different mechanisms have been implicated in its pathophysiology. With respect to autoimmune thrombocytopenia in chronic HCV infection, the detection of specific antibodies against platelet glycoproteins have been reported only in a few studies, but no systematic study has been carried out. We examined the clinical, laboratory, and virological characteristics of a case series of 10 patients with autoimmune thrombocytopenia (platelet count <150.0 x 10(9)/L) related to chronic HCV infection. Cases, six males and four females, aged 57.1 +/- 12.6 years, presented high titers of antibodies against platelet glycoprotein (GP) IIb/IIIa, GP Ia/IIa, and/or GP Ib/IX, and no other mechanism involved in the pathogenesis of HCV-associated thrombocytopenia was identified. Furthermore, cases were not associated with particular HCV genotype. Complete platelet response was observed in two patients treated with pegylated interferon plus ribavirin, and partial platelet response was seen in two patients treated with anti-D Ig and one patient treated with corticosteroids. These findings indicate that an autoimmune mechanism may play a role in the pathogenesis of HCV-associated thrombocytopenia in a proportion of these patients.
No preview · Article · Mar 2009 · Hematology (Amsterdam, Netherlands)
[Show abstract][Hide abstract] ABSTRACT: The present study examined the distribution of hepatitis C virus (HCV) genotypes and subtypes in a hemodialysis population in Goiás State, Central Brazil, and evaluated the efficiency of two genotyping methods: line probe assay (LiPA) based on the 5' noncoding region and nucleotide sequencing of the nonstructural 5B (NS5B) region of the genome. A total of 1095 sera were tested for HCV RNA by RT-nested PCR of the 5' noncoding region. The LiPA assay was able to genotype all 131 HCV RNA-positive samples. Genotypes 1 (92.4%) and 3 (7.6%) were found. Subtype 1a (65.7%) was the most prevalent, followed by subtypes 1b (26.7%) and 3a (7.6%). Direct nucleotide sequencing of 340 bp from the NS5B region was performed in 106 samples. The phylogenetic tree showed that 98 sequences (92.4%) were classified as genotype 1, subtypes 1a (72.6%) and 1b (19.8%), and 8 sequences (7.6%) as subtype 3a. The two genotyping methods gave concordant results within HCV genotypes and subtypes in 100 and 96.2% of cases, respectively. Only four samples presented discrepant results, with LiPA not distinguishing subtypes 1a and 1b. Therefore, HCV genotype 1 (subtype 1a) is predominant in hemodialysis patients in Central Brazil. By using sequence analysis of the NS5B region as a reference standard method for HCV genotyping, we found that LiPA was efficient at the genotype level, although some discrepant results were observed at the subtype level (sensitivity of 96.1% for subtype 1a and 95.2% for subtype 1b). Thus, analysis of the NS5B region permitted better discrimination between HCV subtypes, as required in epidemiological investigations.
Preview · Article · Apr 2007 · Brazilian Journal of Medical and Biological Research
[Show abstract][Hide abstract] ABSTRACT: Fourteen hepatitis C virus (HCV) chronically infected patients were submitted to routine liver biopsy for histological evaluation. Liver samples were assayed to HCV-RNA by in situ hybridization, using digoxigenin labeled probe. HCV genotypes were found to be predominantly type 1 (71.4%), followed by genotype 3 (21.4%), and genotype 2 (7.2%). Alanine-aminotransferase levels were raised in 10 patients. The histopathological scores were minimal (21.4%), mild (57.2%), and moderate (21.4%). Viral RNA was detected in liver cells from nine patients (64.3%). ISH method provides localization and poor confirmation of HCV RNA in the liver tissue of HCV chronic patients.
Full-text · Article · Jun 2005 · Memórias do Instituto Oswaldo Cruz
[Show abstract][Hide abstract] ABSTRACT: Hepatitis B virus (HBV) genotype A has been divided recently into two subgroups, designated A-A' (genotype A excluding A') and A'. Isolates belonging to subgroup A' have been identified in Africa. A new genotyping method, based on PCR amplification of the pre-S/S genome region and subsequent restriction fragment length polymorphism (RFLP) analysis, was developed, that established a correlation between RFLP subtypes and subgroups within genotype A. To investigate the occurrence of subgroup A' in South America, 119 Brazilian HBV isolates were analyzed. Ninety-three (78%) of them belonged to genotype A, with three predominating RFLP subtypes: 44 (37%) isolates were classified as AI, 30 (25%) were AII, and 18 (15%) were AIII. Pre-S/S nucleotide sequences of 15 genotype A isolates were determined. Phylogenetic analysis performed with these 15 and an additional 41 sequences revealed that isolates AI and AII clustered in subgroup A', whereas isolates AIII were classified into subgroup A-A'. The correlation RFLP subtypes-subgroups was confirmed by the presence of amino acid residues specific for subgroup A' in the surface antigens and polymerase of isolates AI and AII. The high proportion (63%) of isolates from subgroup A' suggested an African origin for a large number of Brazilian HBVs.
Full-text · Article · Aug 2004 · Archives of Virology
[Show abstract][Hide abstract] ABSTRACT: The presence of hepatitis B virus (HBV) serological markers was investigated in 170 patients (137 male, 33 female) infected with human immunodeficiency virus (HIV) type 1. Antibodies to the hepatitis B core antigen (anti-HBc antibodies) were detected in 115 (68%) patients. Of these 115, 14 (12%) were hepatitis B surface antigen (HBsAg) positive, 60 (52%) presented anti-HBs antibodies, and 41 (35%) were anti-HBc positive only. All 115 of the anti-HBc positive samples were tested for HBV DNA by using two polymerase chain reaction (PCR) assays that amplify the core and pre-S regions of the HBV genome, respectively. HBV DNA was detected in 23 samples: 7 of 14 (50%) HBsAg-positive samples, 12 of 60 (20%) anti-HBs-positive samples, and 4 of 41 (10%) samples positive for anti-HBc only. Six samples (all HBsAg positive) were positive in both PCR assays and 17 samples were HBV DNA positive in only one assay. The mean viral load in HBsAg-positive patients was higher than that observed in HBsAg-negative patients. A number of patients were receiving treatment with lamivudine, a drug that interferes with both HBV and HIV replication. However, neither the rate of HBV DNA positivity nor HBV load was significantly different between patients treated with lamivudine and those not treated with this drug.
No preview · Article · Mar 2003 · European Journal of Clinical Microbiology
[Show abstract][Hide abstract] ABSTRACT: During an outbreak of hepatitis B virus (HBV) infection in a hemodialysis unit, patients were assessed for serological viral markers and vaccination status. HBV infection was identified in 26 patients. Twenty of these were positive for hepatitis B surface antigen (HBsAg), and 6 were negative for HBsAg but positive for IgM antibody to hepatitis B core (anti-HBc) and HBV DNA. The primary source of infection was not clearly identified, although 2 patients were suspected to be the index cases. A multiple logistic regression analysis revealed low anti-HBs titers and vaccination status to be independently associated with the risk of acquiring HBV infection. Both the high prevalence of HBV infection (31%) detected in this unit and the low vaccine response (53%) observed reinforce the importance of universal and preventive measures in controlling HBV infection. The detection of HBV DNA in HBsAg-negative/IgM anti-HBc-positive patients emphasizes the value of anti-HBc testing in the routine screening of HBV in hemodialysis units.
[Show abstract][Hide abstract] ABSTRACT: The prevalence of antibodies directed against the enterically transmitted hepatitis A virus (HAV) was measured in 2 groups of people living in Rio de Janeiro, Brazil. Of 1,056 health care workers (HCWs), 778 (73.7%) were anti-HAV positive. A high prevalence of anti-HAV antibodies (85.7%) was also found among 274 voluntary blood donors (BDs). TT virus (TTV) is a DNA virus that has been found in the sera of patients with post-transfusion hepatitis of unknown etiology. Occurrence of virus shedding suggests that the fecal-oral route may be an important mode of TTV transmission, particularly in the developing world. The presence of TTV DNA was analyzed by PCR in the sera of 191 HCWs and 151 BDs. TTV was detected in 65.4% of HCWs and 79.5% of BDs. In both groups, a family income of < US$400 per month and a level of education of < 11 y of schooling were found to be risk factors for HAV infection. Furthermore, a low family income was associated with TTV viremia in the HCW group. However, the presence of TTV DNA was associated with neither low level of education nor anti-HAV positivity.
No preview · Article · Feb 2001 · Infectious Diseases
[Show abstract][Hide abstract] ABSTRACT: Hepatitis B vaccine is the most effective strategy for preventing the transmission of hepatitis B virus (HBV) in haemodialysis centers. Nevertheless, lower vaccine responses have been reported in haemodialysis patients as compared with healthy subjects. This study examines the response to Euvax-B in Brazilian haemodialysis patients and staff. A total of 102 eligible patients (n = 42) and staff members (n = 60) consented to be studied. Patients were immunized intramuscularly with four doses of 40 g of Euvax-B vaccine at 0, 1, 2 and 6 months. In staff members, the vaccine was administered in three doses of 20 g at 0, 1, and 6 months. Post-vaccine samples were taken from all subjects 1 month after each dose. The vaccine response was determined by measuring antibody to the hepatitis B surface antigen (anti-HBs) levels using ELISA. Subjects with anti-HBs titres equal to or higher than 10 UI/L were considered immune protected. Of the haemodialysis patients who received four doses of hepatitis B vaccine, 89.5% responded to Euvax-B vaccine. The geometric mean of anti-HBs titres was 322.8 IU/L (95% CI: 317.7–328). Among staff members, 93.3% reached anti-HBs protective titres after the third vaccine dose. The geometric mean of anti-HBs titres was 2209 IU/L (CI: 2198–2219). Age, male gender and body mass index were not associated with vaccine response in either group. This study showed a good immunogenicity response to Euvax-B in haemodialysis patients and staff.
No preview · Article · Jan 2001 · European Journal of Epidemiology