Increasing trends in primary NNRTI resistance among newly HIV-1-diagnosed individuals in Buenos Aires, Argentina

Objective: Our objective was to estimate primary resistance in an urban setting in a developing country characterized by high antiretroviral (ARV) coverage over the diagnosed population and also by an important proportion of undiagnosed individuals, in order to determine whether any change in primary resistance occurred in the past five years. Design: We carried out a multi-site resistance surveillance study according to WHO HIV resistance guidelines, using a weighted sampling technique based on annual HIV case reports per site. Methods: Blood samples were collected from 197 drug-naive HIV-1-infected individuals diagnosed between March 2010 and August 2011 at 20 HIV voluntary counselling and testing centres in Buenos Aires. Clinical records of enrolled patients at the time of diagnosis were compiled. Viral load and CD4 counts were performed on all samples. The pol gene was sequenced and the resistance profile determined. Phylogenetic analysis was performed by neighbour-joining (NJ) trees and bootscanning analysis. Results: We found that 12 (7.9%) of the 152 successfully sequenced samples harboured primary resistance mutations, of which K103N and G190A were the most prevalent. Non-nucleoside reverse transcriptase inhibitors (NNRTI) resistance mutations were largely the most prevalent (5.9%), accounting for 75% of all primary resistance and exhibiting a significant increase (p =0.0072) in prevalence during the past 10 years as compared to our previous study performed in 1997-2000 and in 2003-2005. Nucleoside reverse transcriptase inhibitor (NRTI) and protease inhibitor primary resistance were low and similar to the one previously reported. Conclusions: Levels of primary NNRTI resistance in Buenos Aires appear to be increasing in the context of a sustained ARV coverage and a high proportion of undiagnosed HIV-positive individuals. © 2013 Rodriguez-Rodrigues N et al; licensee International AIDS Society.Fil: Rodriguez Rodrigues, Nahuel Emiliano. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas en Retrovirus y Sida; ArgentinaFil: Duran, Adriana. Ministerio de Salud de la Nación; ArgentinaFil: Bouzas, Maria Belen. Gobierno de la Ciudad de Buenos Aires. Hospital de Infecciosas F. J. Muñiz; ArgentinaFil: Zapiola, Ines. Gobierno de la Ciudad de Buenos Aires. Hospital de Infecciosas F. J. Muñiz; ArgentinaFil: Vila, Marcelo. Organizacion Mundial de la Salud; ArgentinaFil: Indyk, Debbie. Icahn School of Medicine at Mount Sinai; Estados UnidosFil: Bissio, Emiliano. Ministerio de Salud de la Nación; ArgentinaFil: Salomon, Horacio Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas en Retrovirus y Sida; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Microbiología; ArgentinaFil: Dilernia, Dario Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas en Retrovirus y Sida; Argentin

Molecular characterization of hepatitis B virus X gene in chronic hepatitis B patients

BACKGROUND: HBV-X protein is associated with the pathogenesis of HBV related diseases, specially in hepatocellular carcinomas of chronic patients. Genetic variability of the X gene includes genotypic specific variations and mutations emerging during chronic infection. Its coding sequence overlaps important regions for virus replication, including the basal core promoter. Differences in the X gene may have implications in biological functions of the protein and thus, affect the evolution of the disease. There are controversial results about the consequences of mutations in this region and their relationship with pathogenesis. The purpose of this work was to describe the diversity of HBV-X gene in chronic hepatitis patients infected with different genotypes, according to liver disease. METHODS: HBV-X gene was sequenced from chronic hepatitis B patient samples, analyzed by phylogeny and genotyped. Nucleotide and aminoacid diversity was determined calculating intragenetic distances. Mutations at 127, 130 and 131 aminoacids were considered in relation to liver disease. RESULTS: The most prevalent genotype detected in this cohort was F (F1 and F4), followed by D and A. Most of the samples corresponding to genotypes A and F1 were HBeAg(+) and for genotypes D and F4, HBeAg(−) samples were represented in a higher percentage. Intragenetic distance values were higher in HBeAg(−) than in positive samples for all genotypes, and lower in overlapped regions, compared to single codification ones. Nucleotide and aminoacid diversities were higher in HBeAg(−), than in HBeAg(+) samples. CONCLUSIONS: Independently of the infecting genotypes, mutations at any of 127, 130 and/or 131 aminoacid positions and HBeAg(−) status were associated with mild liver disease in this cohort

Role of viral load in Hepatitis B virus evolution in persistently normal ALT chronically infected patients

Chronic HBV infection has been associated with severe liver disease although most of them do not progress to this stage. Even though low replicative carriers form the largest group of HBV chronically infected patients, there is a paucity of longitudinal studies to evaluate the molecular evolution of the whole genome in this subset of patients. In this study, longitudinal samples from 10 patients with persistently normal ALT levels were collected. HBV full-length genome sequences were obtained from 3 samples per patient (baseline, 5 and 10-years of follow-up). Patients were grouped according to HBV-DNA level into  103 IU/ml (group B). The substitution rate was inversely related with HBV-DNA levels. Moreover, the rate in the 10-year follow-up was significantly higher in group A (6.9 × 10−4 ± 1.3 × 10−4) than group B (2.7 × 10−4 ± 7.4 × 10−5 substitution/site/year, p < .001). Most of the substitutions were in the Core region and the majority were non-synonymous changes. The rate of nucleotide substitution was inversely related to HBV-DNA levels, highlighting the role of viral load in the HBV intra-host dynamics, even in low replicative state patients. Moreover, the difference in the substitution rate between the analysed groups was mainly consequence of substitutions restricted to the Core region, particularly in the simple coding region and antigenic epitopes, which suggest that the immune pressure drives the different evolutionary behaviour of groups.Fil: Gauder, Catalina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Microbiología, Inmunología y Biotecnología. Cátedra de Virología; ArgentinaFil: Mojsiejczuk, Laura Noelia. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Microbiología, Inmunología y Biotecnología. Cátedra de Virología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Tadey, Luciana. Gobierno de la Ciudad de Buenos Aires. Hospital de Infecciosas "Dr. Francisco Javier Muñiz"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Mammana, Lilia. Gobierno de la Ciudad de Buenos Aires. Hospital de Infecciosas "Dr. Francisco Javier Muñiz"; ArgentinaFil: Bouzas, Maria Belen. Gobierno de la Ciudad de Buenos Aires. Hospital de Infecciosas "Dr. Francisco Javier Muñiz"; ArgentinaFil: Campos, Rodolfo Hector. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Microbiología, Inmunología y Biotecnología. Cátedra de Microbiología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Flichman, Diego Martin. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Microbiología, Inmunología y Biotecnología. Cátedra de Microbiología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas en Retrovirus y Sida. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas en Retrovirus y Sida; Argentin

The Hepatitis C Virus 5′UTR Genomic Region Remains Highly Conserved Under HAART: A 4- to 8-Year Longitudinal Study from HCV/HIV Co-Infected Patients

Fil: Moretti, Franco. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Microbiología. Area Virologia; ArgentinaFil: Bolcic, Federico Martin. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Microbiología. Area Virologia; ArgentinaFil: Mammana, Lilia. Gobierno de la Ciudad de Buenos Aires. Hospital de Infecciosas ; ArgentinaFil: Bouzas, Maria Belen. Gobierno de la Ciudad de Buenos Aires. Hospital de Infecciosas ; ArgentinaFil: Laufer, Natalia Lorna. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Microbiología. Area Virologia; Argentina. Gobierno de la Ciudad de Buenos Aires. Hospital General de Agudos "Juan A. Fernández"; ArgentinaFil: Quarleri, Jorge Fabian. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Microbiología. Area Virologia; Argentin

Discordances between Interpretation Algorithms for Genotypic Resistance to Protease and Reverse Transcriptase Inhibitors of Human Immunodeficiency Virus Are Subtype Dependent

The major limitation of drug resistance genotyping for human immunodeficiency virus remains the interpretation of the results. We evaluated the concordance in predicting therapy response between four different interpretation algorithms (Rega 6.3, HIVDB-08/04, ANRS [07/04], and VGI 8.0). Sequences were gathered through a worldwide effort to establish a database of non-B subtype sequences, and demographic and clinical information about the patients was gathered. The most concordant results were found for nonnucleoside reverse transcriptase (RT) inhibitors (93%), followed by protease inhibitors (84%) and nucleoside RT inhibitor (NRTIs) (76%). For therapy-naive patients, for nelfinavir, especially for subtypes C and G, the discordances were driven mainly by the protease (PRO) mutational pattern 82I/V + 63P + 36I/V for subtype C and 82I + 63P + 36I + 20I for subtype G. Subtype F displayed more discordances for ritonavir in untreated patients due to the combined presence of PRO 20R and 10I/V. In therapy-experienced patients, subtype G displayed a lot of discordances for saquinavir and indinavir due to mutational patterns involving PRO 90 M and 82I. Subtype F had more discordance for nelfinavir attributable to the presence of PRO 88S and 82A + 54V. For the NRTIs lamivudine and emtricitabine, CRF01_AE had more discordances than subtype B due to the presence of RT mutational patterns 65R + 115 M and 118I + 215Y, respectively. Overall, the different algorithms agreed well on the level of resistance scored, but some of the discordances could be attributed to specific (subtype-dependent) combinations of mutations. It is not yet known whether therapy response is subtype dependent, but the advice given to clinicians based on a genotypic interpretation algorithm differs according to the subtype