Reverse-Transcriptase Characteristics of Hepatitis B Virus Polymerase Gene in Treatment-Naïve Asymptomatic Chronic Hepatitis B Individuals

Nucleos(t)ide analogues (NUCs) remain the main treatment for chronic hepatitis B (CHB). Long-term use of NUCs significantly reduces disease progression; however, it might lead to resistance-associated mutations. We studied characteristics of polymerase gene related to NUCs resistance in naïve hepatitis B surface antigen (HBsAg)-positive individuals. The research was done at Laboratory of Hepatitis, Eijkman Institute, Jakarta Thirty eight samples were obtained and submitted for HBV DNA detection. Identification of mutations was performed by PCR-sequencing, and analyzed to obtain NUCs resistance motifs. Genotype and subtype were determined based on HBsAg sequence. Mutation of rtQ238H/N was found in 37 (97.4%) samples. Of those, 23 (62.2%) showed rtQ238H mutation, 10 (27.0%) had rtQ238N mutation, and four (10.8%) with double mutations of rtA194T and rtQ238H. Genotype B was found in 26 (68.4%), C in 11 (28.9%), and D in one (2.6%) samples. Statistically, the mutation variant of rtQ238H was associated with genotype B (p<0.001), while rtQ238N with C (p<0.001). The ayw subtype was found in 25 (65.8%), adr in 11 (28.9%), and adw in two (5.3%) samples. No mutation associated with NUCs resistance was found in most samples. This emphasizes that NUCs are still a prospective treatment in naïve CHB patients.  Mutation of rtQ238H was a variant found to be significantly associated with HBV genotype B and rtQ238N with genotype C

Second-line antiretroviral therapy in resource-limited settings: the experience of Médecins Sans Frontières

OBJECTIVES: To describe the use of second-line protease-inhibitor regimens in Médecins Sans Frontières HIV programmes, and determine switch rates, clinical outcomes, and factors associated with survival. DESIGN/METHODS: We used patient data from 62 Médecins Sans Frontières programmes and included all antiretroviral therapy-naive adults (> 15 years) at the start of antiretroviral therapy and switched to a protease inhibitor-containing regimen with at least one nucleoside reverse transcriptase inhibitor change after more than 6 months of nonnucleoside reverse transcriptase inhibitor first-line use. Cumulative switch rates and survival curves were estimated using Kaplan-Meier methods, and mortality predictors were investigated using Poisson regression. RESULTS: Of 48,338 adults followed on antiretroviral therapy, 370 switched to a second-line regimen after a median of 20 months (switch rate 4.8/1000 person-years). Median CD4 cell count at switch was 99 cells/microl (interquartile ratio 39-200; n = 244). A lopinavir/ritonavir-based regimen was given to 51% of patients and nelfinavir-based regimen to 43%; 29% changed one nucleoside reverse transcriptase inhibitor and 71% changed two nucleoside reverse transcriptase inhibitors. Median follow-up on second-line antiretroviral therapy was 8 months, and probability of remaining in care at 12 months was 0.86. Median CD4 gains were 90 at 6 months and 135 at 12 months. Death rates were higher in patients in World Health Organization stage 4 at antiretroviral therapy initiation and in those with CD4 nadir count less than 50 cells/microl. CONCLUSION: The rate of switch to second-line treatment in antiretroviral therapy-naive adults on non-nucleoside reverse transcriptase inhibitor-based first-line antiretroviral therapy was relatively low, with good early outcomes observed in protease inhibitor-based second-line regimens. Severe immunosuppression was associated with increased mortality on second-line treatment

Stabilized reverse transcriptase fusion proteins

Stabilized reverse transcriptase fusion proteins including a thermostable reverse transcriptase connected to a stabilizer protein are described. Attaching the stabilizer protein to the thermostable reverse transcriptase stabilizes the fusion protein and can aid in its purification, provide increased solubility, allow for longer storage, or allow the fusion protein to be used under more rigorous conditions such as higher temperature. The stabilized reverse transcriptase fusion protein can also include a linker between the stabilizer protein and the thermostable reverse temperature. The stabilized reverse transcriptase fusion proteins are suitable for use in nucleic acid amplification methods such as the reverse transcription polymerase chain reaction and other applications involving cDNA synthesis.Board of Regents, University of Texas Syste

Detection of viable Mycobacterium ulcerans in clinical samples by a novel combined 16S rRNA reverse transcriptase/IS2404 real-time qPCR assay.

Detection of Viable <em>Mycobacterium ulcerans</em> in Clinical Samples by a Novel Combined 16S rRNA Reverse Transcriptase/IS<em>2404</em> Real-Time qPCR Assa

Higher Efficiency In Prediction Of TIBO Activity By Evolutionary Neural Network

The treatment of acquired immunodeficiency syndrome (AIDS) is a challenging medical problem. TIBO is a nonnucleoside reverse transcriptase inhibitor, which binds non-competitively to the hydrophobic pocket on the p66 subunit of RT enzyme. We used a dataset consisting of physicochemical properties and reverse transcriptase inhibitor activities of 88 set of 4,5,6,7-tetrahydro-y-imidazo-[4,5,1-jk][1,4]-x-benzodiazepin-2-(1h)one derivatives that are variously substituted by halogens, alkyl groups. The dataset was taken from the BIOBYTE database at (www.davidhoekman.com). The concentration of the compound leading to 50% effect has been measured and expressed as IC50. The logarithm of the inverse of this parameter has been used as biological end points (log 1/C) in the QSAR studies. The evolutionary neural network (ENN) is a new system for modeling multivariate data. The strengths of ENN&#x2019;s are that they can extract insignificant predictors, choose the size of the hidden layers and nodes and fine tune the parameters needed in training the network. We have used an ENN to predict the biological activities of Reverse Transcriptase Inhibitors. We have found out that Evolutionary Neural networks are better predictor of activity values than Multiple linear regression and Multilayered Perceptrons. We have calculated the correlation coefficient of each of the methods where we have found ENNs are the best

Prevalence of HIV-1 Drug Resistance among Women Screening for HIV Prevention Trials in KwaZulu-Natal, South Africa (MTN-009)

Background:A major concern with using antiretroviral (ARV)-based products for HIV prevention is the potential spread of drug resistance, particularly from individuals who are HIV-infected but unaware of their status. Limited data exist on the prevalence of HIV infection or drug resistance among potential users of ARV-based prevention products.Methods:A cross-sectional study of reproductive-aged women who presented to screen for an HIV prevention trial was conducted at 7 clinical sites in Durban, South Africa. CD4+T cell counts, HIV-1 RNA levels and population sequencing of the protease and reverse transcriptase genes were performed for all women with 2 positive HIV rapid tests. Resistance mutations were identified using the Stanford Calibrated Population Resistance Tool.Results:Of the 1073 evaluable women, 400(37%) were confirmed as HIV-infected. Of those, plasma HIV-1 RNA was detectable in 365/400(91%) and undetectable(200 copies/ml) analyzed for drug resistance, 26(7.4%) had nucleoside reverse transcriptase inhibitor (NRTI), non-nucleoside reverse transcriptase inhibitor (NNRTI) or protease inhibitor (PI) drug resistance mutations. Among those with resistance, 18/26 participants(62%) had single-class NNRTI resistance and 5/26(19%) had dual-class NRTI/NNRTI. Major mutations in reverse transcriptase included K65R(n = 1), L74I(n = 1), K103N(n = 19), V106M(n = 4), Y181C(n = 2), M184V(n = 4), and K219E/R(n = 2). Major PI-resistance mutations were rare: M46L(n = 1) and I85V(n = 1). All participants were infected with subtype C virus, except one infected with subtype A.Conclusions:In women from Durban, South Africa screening for an HIV prevention trial, the HIV prevalence was high (37%) and HIV drug resistance prevalence was above 5%. This study highlights the potential challenges faced when implementing an ARV-based prevention product that overlaps with first-line antiretroviral therapy. Effective screening to exclude HIV infection among women interested in uptake of ARV-based HIV prevention will be essential in limiting the spread of ARV resistance

Lamarck and immunity: Somatic and germline evolution of antibody genes

Current work on the mechanism of hypermutation of somatically rearranged antibody variable (V) genes shows that the most likely mechanism involves both direct DNA modification (deamination of cytosines to uracils by AID deaminase) and strand nicking plus mRNA editing (deamination of adenosine to inosine via the ADAR1 deaminase) coupled to a reverse transcription process to fix RNA sequence modifications in V gene DNA - most likely involving the repair enzyme DNA polymerase eta (rt) known to be an efficient reverse transcriptase in vitro. The DNA sequence patterns of families of similar germline V genes reveals that many features of somatically mutated and antigen-selected variable genes appear written into the germline V gene arrays of the immune system. Lamarckian gene feedback and cellular reverse transcription, coupled to Darwinian antigen binding selection of somatically mutated V genes, are concepts which appear necessary for a more complete understanding how the V gene complex has evolved. Antibody variable (V) genes of the immune system have therefore been used to test ideas on reverse transcriptase-coupled soma-to-germline feedback in a complex multicellular system. Such feedback constitutes a violation of Weismann's Barrier and thus support for some type of Lamarckian gene feedback operative during the evolution of the vertebrate immune system

Antiretroviral drug resistance mutations in naïve and experienced patients in Shiraz, Iran, 2014

Resistance to antiretroviral agents is a significant concern in the clinical management of HIV-infected individuals, particularly in areas of the world where treatment options are limited. In this study, we aimed to identify HIV drug-resistance-associated mutations in 40 drug-naïve patients and 62 patients under antiretroviral therapy (ART) referred to the Shiraz HIV/AIDS Research Center – the first such data available for the south of Iran. HIV reverse transcriptase and protease genes were amplified and sequenced to determine subtypes and antiretroviral- resistance-associated mutations (RAMs). Subtype CRF35-AD recombinant was the most prevalent in all patients (98 of 102, 96 % ), followed by subtype A1, and subtype B (one each, 2 % ). Among the 40 ART-naïve patients, two mutations associated with nucleoside reverse transcriptase inhibitor (NRTI) resistance (two with Y115F and T215I) and three associated with non-nucleoside reverse transcriptase inhibitor (NNRTI) resistance (two with G190S and Y181C, four with V179T) were found. Among ART-experienced patients, four mutations associated with resistance to NRTI, four with NNRTI, and five with protease inhibitors (PI) were found. Twenty patients with high levels of resistance were already on second-line therapy. We document for the first time in this region of Iran high levels of ART resistance to multiple drugs. Our findings call for more vigilant systematic ART resistance surveillance, increased resistance testing, careful management of patients with existing regimens, and strong advocacy for expansion of available drugs in Iran. © 2016, Springer-Verlag Wien

Factors Associated with the Incidence of Type 2 Diabetes Mellitus in HIV-Infected Participants in the Swiss HIV Cohort Study

Background. Human immunodeficiency virus (HIV)-infected persons may be at increased risk for developing type 2 diabetes mellitus because of viral coinfection and adverse effects of treatment. Methods. We studied associations of new-onset diabetes mellitus with hepatitis B virus and hepatitis C virus coinfections and antiretroviral therapy in participants in the Swiss HIV Cohort Study, using Poisson regression. Results. A total of 123 of 6513 persons experienced diabetes mellitus during 27,798 person-years of follow-up (PYFU), resulting in an incidence of 4.4 cases per 1000 PYFU (95% confidence interval [CI], 3.7-5.3 cases per 1000 PYFU). An increased incidence rate ratio (IRR) was found for male subjects (IRR, 2.5; 95% CI, 1.5-4.2), older age (IRR for subjects >60 years old, 4.3; 95% CI, 2.3-8.2), black (IRR, 2.1; 95% CI, 1.1-4.0) and Asian (IRR, 4.9; 95% CI, 2.2-10.9) ethnicity, Centers for Disease Control and Prevention disease stage C (IRR, 1.6; 95% CI, 1.04-2.4), and obesity (IRR, 4.7; 95% CI, 3.1-7.0), but results for hepatitis C virus infection or active hepatitis B virus infection were inconclusive. Strong associations were found for current treatment with nucleoside reverse-transcriptase inhibitors (IRR, 2.22; 95% CI, 1.11-4.45), nucleoside reverse-transcriptase inhibitors plus protease inhibitors (IRR, 2.48; 95% CI, 1.42-4.31), and nucleoside reverse-transcriptase inhibitors plus protease inhibitors and nonnucleoside reverse-transcriptase inhibitors (IRR, 3.25; 95% CI, 1.59-6.67) but were not found for treatment with nucleoside reverse-transcriptase inhibitors plus nonnucleoside reverse-transcriptase inhibitors (IRR, 1.47; 95% CI, 0.77-2.82). Conclusions. In addition to traditional risk factors, current treatment with protease inhibitor- and nucleoside reverse-transcriptase inhibitor-containing regimens was associated with the risk of developing type 2 diabetes mellitus. Our study did not find a significant association between viral hepatitis infection and risk of incident diabete