Novel HBsAg mutations correlate with hepatocellular carcinoma, hamper HBsAg secretion and promote cell proliferation in vitro

An impaired HBsAg-secretion can increase HBV oncogenic-properties. Here, we investigate genetic-determinants in HBsAg correlated with HBV-induced hepatocellular carcinoma (HCC), and their impact on HBsAg-secretion and cell-proliferation

Virologic Failure of Protease Inhibitor-Based Second-Line Antiretroviral Therapy without Resistance in a Large HIV Treatment Program in South Africa

Background: We investigated the prevalence of wild-type virus (no major drug resistance) and drug resistance mutations at second-line antiretroviral treatment (ART) failure in a large HIV treatment program in South Africa. Methodology/ Principal Findings HIV-infected patients $\geq$15 years of age who had failed protease inhibitor (PI)-based second-line ART (2 consecutive HIV RNA tests >1000 copies/ml on lopinavir/ritonavir, didanosine, and zidovudine) were identified retrospectively. Patients with virologic failure were continued on second-line ART. Genotypic testing for drug resistance was performed on frozen plasma samples obtained closest to and after the date of laboratory confirmed second-line ART failure. Of 322 HIV-infected patients on second-line ART, 43 were adults with confirmed virologic failure, and 33 had available plasma for viral sequencing. HIV-1 RNA subtype C predominated (n = 32, 97%). Mean duration on ART (SD) prior to initiation of second-line ART was 23 (17) months, and time from second-line ART initiation to failure was 10 (9) months. Plasma samples were obtained 7(9) months from confirmed failure. At second-line failure, 22 patients (67%) had wild-type virus. There was no major resistance to PIs found. Eleven of 33 patients had a second plasma sample taken 8 (5.5) months after the first. Median HIV-1 RNA and the genotypic resistance profile were unchanged. Conclusions/ Significance: Most patients who failed second-line ART had wild-type virus. We did not observe evolution of resistance despite continuation of PI-based ART after failure. Interventions that successfully improve adherence could allow patients to continue to benefit from second-line ART therapy even after initial failure

Cross-disease Meta-analysis of Genome-wide Association Studies for Systemic Sclerosis and Rheumatoid Arthritis Reveals IRF4 as a New Common Susceptibility Locus

OBJECTIVES: Systemic sclerosis (SSc) and rheumatoid arthritis (RA) are autoimmune diseases that share clinical and immunological characteristics. To date, several shared SSc-RA loci have been identified independently. In this study, we aimed to systematically search for new common SSc-RA loci through an inter-disease meta-GWAS strategy. METHODS: We performed a meta-analysis combining GWAS datasets of SSc and RA using a strategy that allowed identification of loci with both same-direction and opposing-direction allelic effects. The top single-nucleotide polymorphisms (SNPs) were followed-up in independent SSc and RA case-control cohorts. This allowed us to increase the sample size to a total of 8,830 SSc patients, 16,870 RA patients and 43,393 controls. RESULTS: The cross-disease meta-analysis of the GWAS datasets identified several loci with nominal association signals (P-value < 5 x 10(-6) ), which also showed evidence of association in the disease-specific GWAS scan. These loci included several genomic regions not previously reported as shared loci, besides risk factors associated with both diseases in previous studies. The follow-up of the putatively new SSc-RA loci identified IRF4 as a shared risk factor for these two diseases (Pcombined = 3.29 x 10(-12) ). In addition, the analysis of the biological relevance of the known SSc-RA shared loci pointed to the type I interferon and the interleukin 12 signaling pathways as the main common etiopathogenic factors. CONCLUSIONS: Our study has identified a novel shared locus, IRF4, for SSc and RA and highlighted the usefulness of cross-disease GWAS meta-analysis in the identification of common risk loci

Focus on recently developed assays for detection of resistance/sensitivity to reverse transcriptase inhibitors

The biology of HIV is rather complex due to high rate of replication, frequent recombination, and introduction of mutations. This gives rise to a number of distinct variants referred as quasispecies. In addition, the latency within reservoir allows the periodic reactivation of virus replication. The rapid replication of HIV allows immune response escape and establishment of resistance to therapy that can be acquired through drug selection and/or transmitted among individuals. This prompted, over the years, the development of a range of assays aimed to determine drug resistance and sensitivity, to be used both in clinical practice and in antiviral research. Reverse transcriptase (RT) inhibitors have an eminent place among the anti-HIV drugs, being constantly present from the beginning until today in the most commonly used antiviral regimens. This mini-review seeks to provide an up-to-date overview of recent efforts in developing even more reliable and simple methods, of both genotypic and phenotypic types, for specifically detecting drug resistance and sensitivity to RT inhibitors

Subtype analysis and mutations to antiviral drugs in HIV-1-infected patients from Mozambique before initiation of antiretroviral therapy: Results from the DREAM programme

Phylogenetic analysis and evaluation of drug-resistance were carried out upon 59 plasma samples from 58 treatment-naïve HIV-1 infected patients from Mozambique, enrolled in a free antiviral-therapy protocol in the frame of Drug-Resource-Enhancement against AIDS and Malnutrition (DREAM) programme. Sequencing of the first 1,300 bases of the pol-gene shows that all virus strains cluster within clade C, with the exception of a single patient carrying a G-subtype virus. Relevant mutations in the reverse transcriptase (RT) are rare: 118A/I/L/G (four patients), 179E/D/I (three patients), 333E/D (two patients), 101R, and 210F (one patient each). In Protease (PR), V82I (10.3%) is the only relevant mutation, while natural polymorphisms/secondary mutations are found, some at very high frequency: 20R (25.9%), 36I (91.4%), 36L (8.6%), 60E (31.0%), 63P (29.3%), and 93L (96.6%). Among them, mutations with a frequency >25% were further investigated to assess their covariation pattern with PI resistance associated mutations. The pattern of covariation observed for K20R and D60E (but not L63P and M36I) was different between C and B subtype isolates from PR-inhibitor-treated patients. The sequences were also analyzed to calculate the ratio of non-synonymous to synonymous substitution. The ratio for PR and RT was 0.116 and 0.093, respectively, suggesting a greater conservation in RT than PR in both subtypes B and C HIV strains. Taken together, the results demonstrate a consistent clade-homogeneity of viral strains circulating in Mozambique, and the very limited presence, in drug-naïve patients, of mutations associated with resistance to RT-inhibitors. The high frequency of secondary mutations/polymorphisms in HIV-PR deserves further studies to evaluate its relevance in clinical settings. © 2005 Wiley-Liss, Inc

Time to detection and loss of M184 genotypic mutation among HIV patients treated with 3TC and failing an HAART regimen

Time to detection and loss of M184 genotypic mutation among HIV patients treated with 3TC and failing an HAART regime

Genetic heterogenicity of HIV-1 protease in drug-naive and drug-treated HIV-positive patients

Genetic heterogenicity of HIV-1 protease in drug-naive and drug-treated HIV-positive patient

Factors predictive of multinucleoside analogue-resistance mutations in an unselected cohort of HAART-failed patients.

Factors predictive of multinucleoside analogue-resistance mutations in an unselected cohort of HAART-failed patients

Long-term evaluation of the effect of genotype-based antiretroviral therapy upon virological, immunological, and clinical parameters

Long-term evaluation of the effect of genotype-based antiretroviral therapy upon virological, immunological, and clinical parameter