Hepatitis C and hemodialysis: a review

Hepatitis C is a serious public health problem throughout the world; chronic renal patients are highly exposed to this infection. This could be due to a failure to identify carriers of this disease or because of a lack of truly effective biosafety measures implemented in the dialysis units. Molecular biology techniques have allowed for the understanding of this virus in detail, including its replication mechanisms. Epidemiological studies have been made throughout the world, with the goal of determining the dissemination dynamics of this agent, in addition to examining the predominance of the different genotypes, and the possible mutants that are involved. Many questions must still be answered concerning infection by Hepatitis C virus (HCV); this is especially important for immunosuppressed patients.Adolfo Lutz Institute Virology Service Laboratory of HepatitisIrmandade da Santa Casa de Misericórdia de São PauloFaculty of Medical Sciences Santa Casa de São Paulo Molecular Medicine LaboratoryFederal University of São Paulo Medical School Department of Infectious and Parasitic InfectionsUNIFESP, Medical School Department of Infectious and Parasitic InfectionsSciEL

Characterization of primary direct-acting antiviral (DAA) drugs resistance mutations in NS5A/NS5B regions of hepatitis C virus with genotype 1a and 1b from patients with chronic hepatitis

The Hepatitis C virus (HCV) infection is a public health problem. The high level of HCV replication and its lack of post-transcriptional correction mechanisms results in the emergence of viral variants and the difficulty in determining polymorphisms and variants that contain the substitutions associated with resistance towards new antivirals. The main focus of this study was to map the NS5A and NS5B polymorphisms and resistance mutations to new antiviral drugs in HCV strains genotype 1 from patients with chronic hepatitis C infection. Serum samples were collected from patients who underwent routine viral load tests at the Instituto Adolfo Lutz, Sao Paulo city, Brazil. A total of 698 and 853 samples were used for the characterization of NS5A and NS5B regions, respectively, which comprise the HCV genotypes 1a and 1b. The prevalence of resistance mutations found in the NS5A region was 6.4%, with Y93H, L31M, Q30R, and Y93N as the main resistance-associated substitutions (RAS). No NS5B-associated RAS was observed for any of the analyzed drugs. These findings support that the RAS test should be offered to individuals with poor response to double combination regimens prior to treatment initiation, thereby assisting strain vigilance and selection of effective treatment or retreatment options using DAA regimens

Hepatitis C and hemodialysis: a review

Hepatitis C is a serious public health problem throughout the world; chronic renal patients are highly exposed to this infection. This could be due to a failure to identify carriers of this disease or because of a lack of truly effective biosafety measures implemented in the dialysis units. Molecular biology techniques have allowed for the understanding of this virus in detail, including its replication mechanisms. Epidemiological studies have been made throughout the world, with the goal of determining the dissemination dynamics of this agent, in addition to examining the predominance of the different genotypes, and the possible mutants that are involved. Many questions must still be answered concerning infection by Hepatitis C virus (HCV); this is especially important for immunosuppressed patients

Hepatitis B virus infection in children, adolescents, and their relatives: genotype distribution and precore and core gene mutations

INTRODUCTION:The objectives of this study were evaluate hepatitis B virus (HBV) serological markers in children and adolescents followed up at the Child Institute of the Hospital das Clínicas, Faculdade de Medicina de São Paulo, Universidade de São Paulo; identify chronic HBV carriers and susceptible individuals in the intrafamilial environment; characterize HBV genotypes; and identify mutations in the patients and household contacts. METHODS: Ninety-five hepatitis B surface antigen-positive children aged <19 years and 118 household contacts were enrolled in this study. Commercial kits were used for the detection of serological markers, and PCR was used for genotyping. RESULTS: Hepatitis B e antigen (HBeAg) was detected in 66.3% (63/95) of cases. Three of the 30 HBeAg-negative and anti-HBeAg-positive patients presented with precore mutations and 11 presented with mutations in the basal core promoter (BCP). Genotype A was identified in 39 (43.8%) patients, genotype D in 45 (50.6%), and genotype C in 5 (5.6%). Of the 118 relatives, 40 were chronic HBV carriers, 52 presented with the anti-HBc marker, 19 were vaccinated, and 7 were susceptible. Among the relatives, genotypes A, D, and C were the most frequent. One parent presented with a precore mutation and 4 presented with BCP mutations. CONCLUSIONS: Genotypes A and D were the most frequent among children, adolescents, and their relatives. The high prevalence of HBV in the families showed the possibility of its intrafamilial transmission

Prevalence and risk factors of hepatitis C virus infection in hemodialysis patients from one center in Recife, Brazil

A hemodialysis population from a dialysis unit in the city of Recife, Northeastern Brazil, was screened to assess the prevalence of hepatitis C virus (HCV) infection and to investigate the associated risk factors. Hemodialysis patients (n = 250) were interviewed and serum samples tested for anti-HCV antibodies by enzyme-linked immunosorbent assay (ELISA). All samples were also tested for HCV RNA by reverse transcriptase nested polymerase chain reaction (RT-nested-PCR). Out of 250 patients, 21 (8.4%) were found to be seropositive by ELISA, and 19 (7.6%) patients were HCV RNA positive. HCV viraemia was present in 90.5% of the anti-HCV positive patients. The predominant genotype was HCV 1a (8/19), followed by 3a (7/19), and 1b (4/19). None of the anti-HCV negative patients were shown to be viraemic by the PCR. Univariate analysis of risk factors showed that time spent on hemodialysis, the number of blood transfusions and a blood transfusion before November 1993 were associated with HCV positivity. However, multivariate analysis revealed that blood transfusions before November 1993 were significantly associated with HCV infection in this population. Low prevalence levels were encountered in this center, however prospective studies are necessary to confirm these findings

Prevalence and risk factors of hepatitis C virus infection in hemodialysis patients from one center in Recife, Brazil

A hemodialysis population from a dialysis unit in the city of Recife, Northeastern Brazil, was screened to assess the prevalence of hepatitis C virus (HCV) infection and to investigate the associated risk factors. Hemodialysis patients (n = 250) were interviewed and serum samples tested for anti-HCV antibodies by enzyme-linked immunosorbent assay (ELISA). All samples were also tested for HCV RNA by reverse transcriptase nested polymerase chain reaction (RT-nested-PCR). Out of 250 patients, 21 (8.4%) were found to be seropositive by ELISA, and 19 (7.6%) patients were HCV RNA positive. HCV viraemia was present in 90.5% of the anti-HCV positive patients. The predominant genotype was HCV 1a (8/19), followed by 3a (7/19), and 1b (4/19). None of the anti-HCV negative patients were shown to be viraemic by the PCR. Univariate analysis of risk factors showed that time spent on hemodialysis, the number of blood transfusions and a blood transfusion before November 1993 were associated with HCV positivity. However, multivariate analysis revealed that blood transfusions before November 1993 were significantly associated with HCV infection in this population. Low prevalence levels were encountered in this center, however prospective studies are necessary to confirm these findings

Precisão dos testes sorológico e molecular para diagnóstico do HBV e HCV em pacientes com Insuficiência Renal Crônica em hemodiálise, em Porto Velho, Brasil

Patients under hemodialysis treatment for chronic renal failure (CRF) are among the groups with the highest prevalence of hepatitis B and C viruses due to frequent blood transfusions and nosocomial transmission. A group of CRF patients living in Porto Velho were tested with serological markers for hepatitis B and C using the ELISA test and molecular biology techniques (PCR). The validity parameters for the serological results were measured based on the PCR results. Of the 128 patients on hemodialysis during the study, 12 (9.4%) were HBsAg positive, 69 (53.9%) were anti-HBc positive, 93 (72.7%) were anti-HBs positive, and 22 (17.2%) were anti-HCV positive. The PCR tests result in 12 (9.4%) HBV-DNA positive and 16 (12.5%) HCV-RNA positive. The accuracy, sensitivity and specificity of ELISA for HBsAg were 90.6%, 50% and 94.8%, and the same parameters were 92.2%, 87.5% and 92.9% for anti-HCV. Based on the results just the negative predictive value for anti-HCV (98,2%) is a reliable test in CRF patients on hemodialysis. Beside that, serial serological and/or molecular tests are the indicated methodology to diagnosis HBV and HCV infection in these patients.Pacientes em tratamento com hemodiálise para a Insuficiência Renal Crônica (IRC) estão entre os grupos com maior prevalência da infecção pelo vírus da hepatite B e C, devido às transfusões de sangue e transmissão nosocomial. Um grupo de pacientes com IRC residentes em Porto Velho foi testado com marcadores sorológicos para hepatite B e C utilizando o teste ELISA e técnicas de biologia molecular (PCR). Os parâmetros para a validação dos resultados sorológicos foram medidos com base nos resultados da PCR. Dos 128 pacientes em hemodiálise durante o estudo, 12 (9,4%) eram HBsAg positivos, 69 (53,9%) eram anti-HBc positivos, 93 (72,7%) eram anti-HBs positivos, e 22 (17,2%) eram anti- HCV positivos. Os resultados dos testes com PCR foram de 12 (9,4%) HBV-DNA positivos e 16 (12,5%) HCV-RNA positivos. A precisão, sensibilidade e especificidade do ELISA para o HBsAg foram de 90,6%, 50% e 94,8%, e os mesmos parâmetros foram de 92,2%, 87,5% e 92,9% para anti-HCV. Com base nos resultados, apenas o valor preditivo negativo para anti-HCV (98,2%) mostrou-se confiável em pacientes renais crônicos em hemodiálise. Além disto, testes sorológicos e/ou moleculares representam a metodologia indicada para o diagnóstico da infecção pelo HBV e HCV nestes pacientes