Identification of hepatitis B virus A1762T/G1764A double mutant strain in patients in Southern Brazil

Abstract Infection by hepatitis B virus (HBV) is a worldwide public health problem. Chronic HBV infection with high viral replication may lead to cirrhosis and/or hepatocellular carcinoma. Mutant HBV strains, such as the HBV A1762T/G1764A double mutant, have been associated with poor prognosis and higher risk of the patient for developing cirrhosis and/or hepatocellular carcinoma. This study analyzed the presence of the HBV A1762T/G1764A double mutant in patients with chronic HBV and its association with clinical parameters such as viral load, aminotransferases, and HBV antigens. A total of 49 patients with chronic hepatitis B were included in the study, and the HBV A1762T/G1764A double mutant strain was detected in four samples (8.16%) by polymerase chain reaction followed by restriction fragment length analysis (PCR-RFLP). The viral load was not significantly different between patients with or without the double mutant strain (p = 0.43). On the other hand, carriers of the HBV A1762T/G1764A double mutant had higher levels of ALT (p = 0.0028), while AST levels did not differ between groups (p = 0.051). In this study, 75% of the samples with the HBV A1762T/G1764A double mutation were HBeAg negative and anti-HBe positive, reflecting seroconversion even though they still displayed high viral loads. Our study has shown that the HBV A1762T/G1764A double mutant strain circulates in Brazilian patients, and is associated with elevated levels of ALT and HBeAg seroconversion.

Identification of hepatitis B virus A1762T/G1764A double mutant strain in patients in Southern Brazil.

Infection by hepatitis B virus (HBV) is a worldwide public health problem. Chronic HBV infection with high viral replication may lead to cirrhosis and/or hepatocellular carcinoma. Mutant HBV strains, such as the HBV A1762T/G1764A double mutant, have been associated with poor prognosis and higher risk of the patient for developing cirrhosis and/or hepatocellular carcinoma. This study analyzed the presence of the HBV A1762T/G1764A double mutant in patients with chronic HBV and its association with clinical parameters such as viral load, aminotransferases, and HBV antigens. A total of 49 patients with chronic hepatitis B were included in the study, and the HBV A1762T/G1764A double mutant strain was detected in four samples (8.16%) by polymerase chain reaction followed by restriction fragment length analysis (PCR-RFLP). The viral load was not significantly different between patients with or without the double mutant strain (p=0.43). On the other hand, carriers of the HBV A1762T/G1764A double mutant had higher levels of ALT (p=0.0028), while AST levels did not differ between groups (p=0.051). In this study, 75% of the samples with the HBV A1762T/G1764A double mutation were HBeAg negative and anti-HBe positive, reflecting seroconversion even though they still displayed high viral loads. Our study has shown that the HBV A1762T/G1764A double mutant strain circulates in Brazilian patients, and is associated with elevated levels of ALT and HBeAg seroconversion.

Frequency of the mdr1 gene polymorphism rs1045642 (c3435t) in hcv-hiv co-infected patients / Frequência do polimorfismo rs1045642 (C3435T) do gene MDR1 em pacientes coinfectados HCV-HIV

ABSTRACT Background Due to the high prevalence of co-infection by hepatitis C virus (HCV) and human immunodeficiency virus (HIV) and the severity of these infections, the understanding of the biological mechanisms involved in these processes, including viral behavior and host genetic profile, is of great importance for patient treatment and for public health policies.Some single nucleotide polymorphisms (SNPs) in the human genome, such as the SNP rs1045642 (C3435T) in the MDR1 gene, have been reported to be associated to the sustained virological response (SVR) to HCV treatment in HCV-HIV co-infected patients. Objective The present study analyzes the MDR1 gene C3435T polymorphism in HCV-HIV co-infected patients. Methods A total of 99 HCV-HIV patients were included in the study. The DNA was extracted from blood samples, and the SNP rs1045642 was assessed by Real Time PCR (qPCR). Risk factors for acquiring the virus and the SVR after HCV treatment with pegylated interferon-alpha and ribavirin were also analyzed. Results Among the patients, 54 (54.5%) were male and 45 (45.5%) were female. The average age was 46.1±9.8 years. The SVR after HCV treatment was 40%. The frequencies of MDR1 genotypes CC, CT and TT were 28.3%, 47.5% and 24.2%, respectively. Allele frequencies were 52% for the C allele and 48% for the T allele. No association was found for SNP rs1045642 (C3435T) regarding response to treatment (P=0.308). Conclusion - In this study, the C3435T polymorphism in the MDR1 gene appears not to be associated with SVR in HCV-HIV co-infected individuals.

RESUMO Contexto Em virtude da elevada prevalência da coinfecção pelos vírus da hepatite C (HCV) e da imunodeficiência humana (HIV) e às inúmeras complicações que esses vírus acarretam, é fundamental o maior entendimento do comportamento biológico dos mesmos. O polimorfismo de nucleotídeo único rs1045642 C3435T do gene de resistência a múltiplas drogas MDR1, no qual ocorre modificação do códon ATC para ATT, parece estar relacionado à resposta virológica sustentada ao tratamento do HCV em coinfectados HCV-HIV. Objetivo Mapear o polimorfismo C3435T do gene MDR1 em pacientes coinfectados HCV-HIV e correlacionar com dados clínicos e laboratoriais. Métodos Foram analisados 99 pacientes coinfectados HCV-HIV. A identificação molecular do polimorfismo de nucleotídeo único rs1045642 do gene MDR1 foi realizada pela técnica de PCR em tempo real (qPCR) alelo-específico com primers e sondas específicos para a identificação desse polimorfismo. Fatores de risco para a aquisição do HCV e a resposta virológica sustentada ao tratamento do HCV com interferon-alfa peguilado e ribavirina foram analisados. Resultados Dentre os pacientes avaliados, 54 (54,5%) eram do gênero masculino e 45 (45,5%) do gênero feminino. A média de idade foi de 46,1 anos (±9,8). As frequências dos genótipos CC, CT e TT foram 28,3%, 47,5% e 24,2% respectivamente, e as frequências alélicas foram 52% para alelo C e 48% para alelo T. Não houve associação entre o gene MDR1 e a resposta virológica sustentada (P=0,308). Conclusão Neste estudo, o polimorfismo C3435T no gene MDR1 não apresentou associação com a resposta virológica sustentada ao tratamento em indivíduos coinfectados HCV-HIV.

Cationic Nanoemulsions as a Gene Delivery System: Proof of Concept in the Mucopolysaccharidosis I Murine Model.

Mucopolysaccharidosis I (MPS I) is an autosomal recessive lysosomal storage disease due to deficient a-L-iduronidase (IDUA) activity. It results in the accumulation of the glycosaminoglycans (GAGs) heparan and dermatan sulfate and leads to several clinical manifestations. This study describes the use of cationic nanoemulsions as a non-viral carrier for the plasmid named pIDUA, which has the gene that encodes for the IDUA enzyme. Cationic nanoemulsions, composed by a medium chain triglycerides oil core stabilized by DOTAP, DOPE and DSPE-PEG, were prepared by high pressure homogeneization. pIDUA was complexed with nanoemulsions in the end of manufacturing process. Physicochemical properties of complexes were influenced by the charge ratio used. From a charge ratio of +2/-, it was observed a total complexation of pIDUA with formulation as well as a protection of plasmid against DNAse I digestion. In vitro assay in fibroblasts of one MPS I patient presented greater and significant trasfection efficiency for pIDUA complexed to formulation in the +4/- charge ratio. This formulation was administered via the tail vein and the portal vein. Animals were compared to untreated MPS I mice. Transfection efficiency was measured as IDUA enzyme activity. After intravenous administration, IDUA activity was significantly higher in lungs and liver. The set of results shows the formulation obtained at the +4/- charge ratio as a promising non-viral gene delivery system, once showed increased enzyme activity both in vitro and in vivo.

Evaluation of the C3435T polymorphism in the MDR1 gene in patients with hepatocellular carcinoma.

INTRODUCTION: Considering the high prevalence of liver tumors and the impact on patient survival, a greater understanding of the biological behavior of those tumors if of great importance. The multidrug resistance gene (MDR1) may present as single nucleotide polymorphism (SNP) which can affect the expression and activity of P-glycoprotein (Pgp), and high expression of Pgp has been associated with a worse prognosis in affected patients. OBJECTIVE: To correlate the C3435T polymorphism in the MDR1 gene with the immunohistochemical expression of Pgp. MATERIAL AND METHODS: A total of 67 samples from patients with diagnosis of hepatocellular carcinoma (HCC), collected in the period from 2000 to 2009, were analyzed. The polymorphism in the MDR1 gene was determined by the technique of allele-specific real time PCR using TaqMan assay, and the expression of protein Pgp was evaluated by immunohistochemistry. RESULTS: Among the samples evaluated, 56 (83.6%) were from male patients and 11 (16.4%) from females. Mean age was 60.6 years (± 8.8), ranging from 37 to 85 years. The etiology of the HCC was related to hepatitis C virus infection (HCV) in 31 (46.3%) of cases, followed by hepatitis C virus infection + alcohol in 24 cases (35.8%), alcohol in 4 cases (6)%, hepatitis B virus (HBV) in 4 cases (6%) and other factors in 4 cases (6%). Liver transplantation was performed in 48 cases (71.6%) and hepatectomia in 19 cases (28.4%). The genotypes CC, CT and TT showed frequencies of 25.4%, 41.8% and 32.8%, respectively, and the allele frequencies were 46.3% for allele C and 53.7% for allele T. The expression of Pgp in over 75% of the cells was significantly more frequent in tumor tissue. On the other hand, a low expression of Pgp, in less than 25% of the cells, was significantly more frequent in non-tumor tissue. The Pgp expression in more than 50% of tumor cells of individuals with genotypes CC, CT and TT was 15.7%, 51.0% and 33.3%, respectively, and was significantly higher when in the presence of allele T (p = 0.002). CONCLUSION: The presence of the polymorphic allele T is related to increased expression of Pgp protein in patients with HCC.