Proposal of pharmacophore model for HIV reverse transcriptase inhibitors: Combined mutational effect analysis, molecular dynamics, molecular docking and pharmacophore modeling study.

OBJECTIVES: Antiretroviral therapy (ART) efficacy is jeopardized by the emergence of drug resistance mutations in HIV, compromising treatment effectiveness. This study aims to propose novel analogs of Effavirenz (EFV) as potential direct inhibitors of HIV reverse transcriptase, employing computer-aided drug design methodologies. METHODS: Three key approaches were applied: a mutational profile study, molecular dynamics simulations, and pharmacophore development. The impact of mutations on the stability, flexibility, function, and affinity of target proteins, especially those associated with NRTI, was assessed. Molecular dynamics analysis identified G190E as a mutation significantly altering protein properties, potentially leading to therapeutic failure. Comparative analysis revealed that among six first-line antiretroviral drugs, EFV exhibited notably low affinity with viral reverse transcriptase, further reduced by the G190E mutation. Subsequently, a search for EFV-similar inhibitors yielded 12 promising molecules based on their affinity, forming the basis for generating a pharmacophore model. RESULTS: Mutational analysis pinpointed G190E as a crucial mutation impacting protein properties, potentially undermining therapeutic efficacy. EFV demonstrated diminished affinity with viral reverse transcriptase, exacerbated by the G190E mutation. The search for EFV analogs identified 12 high-affinity molecules, culminating in a pharmacophore model elucidating key structural features crucial for potent inhibition. CONCLUSION: This study underscores the significance of EFV analogs as potential inhibitors of HIV reverse transcriptase. The findings highlight the impact of mutations on drug efficacy, particularly the detrimental effect of G190E. The generated pharmacophore model serves as a pivotal reference for future drug development efforts targeting HIV, providing essential structural insights for the design of potent inhibitors based on EFV analogs identified in vitro.

Biochemical and structural comparisons of non-nucleoside reverse transcriptase inhibitors against feline and human immunodeficiency viruses.

BACKGROUND: Feline immunodeficiency virus (FIV) causes an acquired immunodeficiency-like syndrome in cats. FIV is latent. No effective treatment has been developed for treatment the infected cats. The first and second generations non-nucleoside reverse transcriptase inhibitors (NNRTIs) for HIV treatment, nevirapine (NVP) and efavirenz (EFV), and rilpivirine (RPV), were used to investigate the potential of NNRTIs for treatment of FIV infection. OBJECTIVE: This study aims to use experimental and in silico approaches to investigate the potential of NNRTIs, NVP, EFV, and RPV, for inhibition of FIV reverse transcriptase (FIV-RT). METHODS: The FIV-RT and human immunodeficiency virus reverse transcriptase (HIV-RT) were expressed and purified using chromatography approaches. The purified proteins were used to determine the IC50 values with NVP, EFV, and RPV. Surface plasmon resonance (SPR) analysis was used to calculate the binding affinities of NNRTIs to HIV-RT and FIV-RT. The molecular docking and molecular dynamic simulations were used to demonstrate the mechanism of FIV-RT and HIV-RT with first and second generation NNRTI complexes. RESULTS: The IC50 values of NNRTIs NVP, EFV, and RPV against FIV-RT were in comparable ranges to HIV-RT. The SPR analysis showed that NVP, EFV, and RPV could bind to both enzymes. Computational calculation also supports that these NNRTIs can bind with both FIV-RT and HIV-RT. CONCLUSIONS: Our results suggest the first and second generation NNRTIs (NVP, EFV, and RPV) could inhibit both FIV-RT and HIV-RT.

The impact of the M184V resistance mutation on treatment outcomes in patients with HIV infection: a systematic review and meta-analysis.

HIV is a global deliberating infectious disease. Of note, more than 36 million people living with HIV (PLHIV) with approximately newly diagnosed 1.5 million cases annually. M184V is a single base mutation in the highly conserved YMDD domain of reverse transcriptase (RT). It is one of the most encountered resistances associated with mutations to nucleoside RT inhibitors. There were continuous efforts to evaluate the impact of M184V mutation on the treatment outcomes in PLHIV. Therefore, the present systematic review was executed to reveal the virological failure, virological suppression, and resistance to antiretroviral therapy (ART) regimens in PLHIV with the M184V mutation. All clinical studies comparing the treatment outcomes among PLHIV harboring or not harboring M184V mutation were appropriate for systematic review and meta-analysis. The present systematic review included six articles, encompassing 4760 PLHIV. Of them, 1222 (25.67%) patients had M184V mutation, while 3538 (74.32%) PLHIV did not. The meta-analysis showed that patients with M184V mutation were 1.87 times more liable to virological failure (risk ratio [RR] 1.87; 95% 1.09, 3.20; p = 0.02). Furthermore, pooling the data from two studies revealed a significantly higher risk of viral blips (RR 2.26; 95% 1.47, 3.46; p = 0.0002). Concerning discontinuation of ART, there was no statistical difference between patients with and without M184V mutation (RR: 0.99; 95% 0.78, 1.25; p = 0.90). The present study revealed the negative impact of the M184V mutation on treatment outcomes in PLHIV. This included a higher risk of virological failure and viral blips, relative to patients without the mutation. Such patients may benefit from more aggressive and combined therapy for better disease management.

Resistance levels to non-nucleoside reverse transcriptase inhibitors among pregnant women with recent HIV infection in Malawi.

BACKGROUND: Information on HIV drug resistance (HIVDR) prevalence in people newly diagnosed with HIV is limited. We implemented a cross-sectional study to estimate HIVDR prevalence among pregnant women recently infected with HIV in Malawi. METHODS: The HIVDR study was nested within a routine antenatal clinic (ANC) sentinel surveillance survey. Dried blood spot samples were tested for recent infection using a limiting antigen antibody assay together with HIV viral load testing. HIV-1 protease and reverse transcriptase were sequenced using Sanger sequencing. Drug susceptibility was predicted using Stanford HIVdb algorithm (version 8.9). Weighted analysis was performed in Stata 15.1. RESULTS: Of the 21,642 pregnant women enrolled in the ANC survey, 8.4% (1826/21,642) tested HIV positive. Of these, 5.0% (92/1826) had recent HIV infection, and 90.2% (83/92) were tested by PCR. The amplification and sequencing success rate was 57.8% (48/83). The prevalence of any HIVDR was 14.6% (5/45) (95% CI: 4.7-36.8%), all of which indicated HIVDR to nonnucleoside reverse transcriptase inhibitors (NNRTIs). HIVDR to nucleoside reverse transcriptase inhibitors was 7.9% (2/45) (95% CI: 1.4-34.6%). Resistance to protease inhibitors currently in use in Malawi was not observed. CONCLUSIONS: Despite the low number of cases with presumed TDR, our study hints that resistance to NNRTIs was high, above the 10% target for regimen change. Further investigation is needed to establish the exact magnitude of presumed TDR among women recently infected with HIV. These findings support the transition to an integrase inhibitor-based first-line regimen for patients initiating or on ART.

Retroviral reverse transcriptase: Structure, function and inhibition.

Reverse transcriptase (RT) is a multifunctional enzyme that has RNA- and DNA-dependent DNA polymerase activity and ribonuclease H (RNase H) activity, and is responsible for the reverse transcription of retroviral single-stranded RNA into double-stranded DNA. The essential role that RT plays in the human immunodeficiency virus (HIV) life cycle is highlighted by the fact that multiple antiviral drugs-which can be classified into two distinct therapeutic classes-are routinely used to treat and/or prevent HIV infection. This book chapter provides detailed insights into the three-dimensional structure of HIV RT, the biochemical mechanisms of DNA polymerization and RNase H activity, and the mechanisms by which nucleoside/nucleotide and nonnucleoside RT inhibitors block reverse transcription.

HIV-1 drug resistance among individuals who seroconverted in the ASPIRE dapivirine ring trial.

INTRODUCTION: A potential concern with the use of dapivirine (DPV) for HIV prevention is the selection of a drug-resistant virus that could spread and reduce the effectiveness of non-nucleoside reverse transcriptase (NNRTI)-based first-line antiretroviral therapy. We evaluated HIV-1 seroconversions in MTN-020/ASPIRE for selection of drug resistance and evaluated the genetic basis for observed reductions in susceptibility to DPV. METHODS: MTN-020/ASPIRE was a placebo-controlled, Phase III safety and effectiveness study of DPV ring for HIV-1 prevention conducted at 15 sites in South Africa, Zimbabwe, Malawi and Uganda between 2012 and 2015. Plasma from individuals who seroconverted in ASPIRE was analysed for HIV-1 drug resistance using both population Sanger sequencing and next-generation sequencing (NGS) with unique molecular identifiers to report mutations at ≥1% frequency. DPV susceptibility of plasma-derived recombinant HIV-1 containing bulk-cloned full-length reverse transcriptase sequences from MTN-020/ASPIRE seroconversions was determined in TZM-bl cells. Statistical significance was calculated using the Fisher's exact test. RESULTS: Plasma from all 168 HIV seroconversions were successfully tested by Sanger sequencing; 57 of 71 DPV arm and 82 of 97 placebo (PLB) arm participants had NGS results at 1% sensitivity. Overall, 18/168 (11%) had NNRTI mutations including K101E, K103N/S, V106M, V108I, E138A/G, V179D/I/T and H221Y. Five samples from both arms had low-frequency NNRTI mutations that were not detected by Sanger sequencing. The frequency of NNRTI mutations from the DPV arm (11%) was not different from the PLB arm (10%; p = 0.80). The E138A mutation was detected in both the DPV (3 of 71 [4.2%]) and PLB arm (5 of 97 [5.2%]) and conferred modest reductions in DPV susceptibility in some reverse transcriptase backgrounds but not others. CONCLUSIONS: HIV-1 drug resistance including NNRTI resistance did not differ between the DPV and placebo arms of the MTN-020/ASPIRE study, indicating that drug resistance was not preferentially acquired or selected by the DPV ring and that the preventive benefit of DPV ring outweighs resistance risk.

[Study of the specific toxic effects of the substance 1-[2-(2-benzoylphenoxy)ethyl]-6-methyluracil, the original non-nucleoside inhibitor of human immunodeficiency virus type 1 (Retroviridae; Orthoretrovirinae; Lentivirus: Human immunodeficiency virus 1) reverse transcriptase].

INTRODUCTION: Combination antiretroviral therapy is currently the main component of treatment for human immunodeficiency virus (HIV) infected patients. At the same time, the high mutational potential of the virus and the frequency of side effects of existing drugs dictate the need for the development and preclinical study of new, more effective and safer compounds.The aim of the study is to evaluate the specific types of toxicity of a new non-nucleoside inhibitor of human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RNA-dependent DNA revertase) (NNRTI) based on the substance 1-[2-(2-benzoylphenoxy)ethyl]-6-methyluracil, a benzophenone derivative. MATERIAL AND METHODS: The study investigated reproductive toxicity, embryotoxicity, immunotoxicity, genotoxic (in micronucleus test in and comet assay) and allergenic properties of the test itemcompound. It was tested on three species of animals in two doses: the estimated therapeutic dose (1 TD) and its tenfold equivalent (10 TD). Taking into account the metabolic coefficients, the doses for rats (Rattus) were 9 and 90 mg/kg, for mice (Mus musculus), 21 and 210 mg/kg, and for guinea pigs (Cavia porcellus), 8 and 80 mg/kg, respectively. RESULTS AND DISCUSSION: According to the obtained results, a favorable safety profile of the tested compound was established. Negative effects on the immune system, reproductive function, the body of pregnant animals and the fetus were not observed, as well as the compound did not have genotoxic and allergenic properties. CONCLUSION: These data allows to consider the studied compound as a promising therapeutic candidate for the treatment of HIV-1 infection.

Small Conformational Changes Underlie Evolution of Resistance to NNRTI in HIV Reverse Transcriptase.

Despite achieving considerable success in reducing the number of fatalities due to acquired immunodeficiency syndrome, emergence of resistance against the reverse transcriptase (RT) inhibitor drugs remains one of the biggest challenges of the human immunodeficiency virus antiretroviral therapy (ART). Non-nucleoside reverse transcriptase inhibitors (NNRTIs) form a large class of drugs and a crucial component of ART. In NNRTIs, even a single resistance mutation is known to make the drugs completely ineffective. Additionally, several inhibitor-bound RTs with single resistance mutations do not exhibit any significant variations in their three-dimensional structures compared with the inhibitor-bound RT but completely nullify their inhibitory functions. This makes understanding the structural mechanism of these resistance mutations crucial for drug development. Here, we study several single resistance mutations in the allosteric inhibitor (nevirapine)-bound RT to analyze the mechanism of small structural changes leading to these large functional effects. In this study, we have shown that in absence of significant conformational variations in the inhibitor-bound wild-type RT and RT with single resistance mutations, the protein contact network analysis of their static structures, along with molecular dynamics simulations, can be a useful approach to understand the functional effect of small local conformational variations. The simple network analysis exposes the localized contact changes that lead to global rearrangement in the communication pattern within RT. Furthermore, these conformational changes have implications on the overall dynamics of RT. Using various measures, we show that a single resistance mutation can change the network structure and dynamics of RT to behave more like unbound RT, even in the presence of the inhibitor. This combined coarse-grained contact network and molecular dynamics approach promises to be a useful tool to analyze structure-function studies of proteins that show large functional changes with negligible variations in their overall conformation.

Mini Review - Epigenetics: Quest for no-escape to HIV, a persistent pathogen.

Acquired Immune Deficiency Syndrome (AIDS) is a disease infection mix, which is primarily because of 'deficient' immune system. Human Immune-deficiency Virus (HIV) makes the immune system susceptible to many infections by infiltrating it. Many researchers believe that HIV is a mutated form of Simian Immune-deficiency Virus (SIV). After being clinically discovered in 1981 in America, it is said to have caused 36 million deaths. Treatment of AIDS has been a 'burning ' issue ever since its discovery. There is no cure for AIDS! Although, Recombinant Transcriptase Inhibitors (RTis) are being considered a major treatment against HIV that can not only lessen the effect of HIV but also can prolong the life of HIV positive patients. More recent advancement includes 'transplantation of transgenic stem cells' in HIV positive patients. As latency of HIV provirus in host genome is the preeminent weapon of this virus against RTis that compel it to hide from host immune system and a persistent pathogen thereof. Thus, epigenetic activation of latent provirus pool by methyl inhibitors along with non¬toxic chemical drugs seems to be a more promising treatment to avoid the burden of lifelong RTI.

[Diversity of HIV-1 subtypes and primary HIV-1 drug resistance among 302 newly confirmed HIV infections/AIDS in Henan province, China].

OBJECTIVE: To investigate HIV-1 subtype diversity and the frequency of primary drug resistance in newly confirmed HIV infections/AIDS, and the ratio of recently infected cases in Henan. METHODS: Newly confirmed HIV infections/AIDS from June 2013 to October 2013 and from June 2014 to October 2014 in the municipal CDC and county CDC of six cities in Henan province (Nanyang, Luohe, Pingdingshan, Shangqiu, Xuchang and Zhengzhou) were included in this study. Information on demographics, route of infection and antiviral therapy regimen were obtained from report cards, and at follow-up visits. After collection of blood samples from 402 individuals for confirmatory diagnostic tests, 100 were excluded because of hemolysis or insufficient samples in 11 cases, and incomplete amplification results in 89 cases. Recent HIV infection was determined by the BED capture immunoassay. An in-house method were used for genotypic drug resistance tests and sequence analysis. RESULTS: Among the 302 individuals included, the mean age was (44.0±15.5) years, and 160 (53.0%) and 142 (47.0%) cases were confirmed in 2013 and 2014, respectively. The ratio of recent infections was 29.5% (89 cases), inside, the ratio of recent infections were 31.3% (20/64), 40.5% (30/74), 21.3% (32/150), 3/8 and 4/6 in 01_AE, 07_BC, B, 01_B and other subtypes (B/C, C, 01_BC and 08_BC) (χ(2)=13.48, P=0.009). The frequency of the B subtype was higher in former infections, at 55.4% (118/213), than in recent infections, at 36% (32/89) (χ(2)=9.49, P=0.002). In contrast, the ratios of both 07_BC and other subtypes were lower in former infections (20.7% (44/213) and 1% (2/213), respectively) than recent infections (33.7% (30/89), χ(2)=5.78, P=0.016 and 5% (4/89), χ(2)=4.08; P=0.044, respectively). The frequency of primary HIV-1 drug resistance was 6.0% (18 cases) in 302 subjects. The frequency of resistance to nucleoside reverse transcriptase inhibitor (NRTI) and non-nucleoside reverse transcriptase inhibitor (NNRTI) drugs was 2.7% (8 cases) and 3.6% (11 cases), respectively. Primary HIV-1 drug resistance was more frequent in subtypes B and 07_BC, at 8.7% (13 cases) and 5.4% (4 cases), respectively. CONCLUSION: Newly confirmed HIV infections/AIDS in Henan province harbored certain proportion of none-B subtypes, the frequency of primary resistance tended to be high in HIV-1B infection. The molecular epidemiology of HIV and the development of primary drug resistance should be regularly monitored.

Rilpivirine resistance associated mutations in HIV-1 infected pregnant women / Mutaciones asociadas a resistencia a rilpivirina en embarazadas infectadas por VIH-1

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Impacto del tratamiento antirretroviral en la función sexual de mujeres con VIH / Impact of antiretroviral treatment on sexual function of HIV-infected women

Objetivo. Describir la función sexual de un grupo de mujeres con VIH bajo tratamiento antirretroviral. Evaluar si existe diferencia entre las tratadas con un esquema que contiene Inhibidores No Nucleósidos de la Transcriptasa Inversa (INNTI) y aquéllas que reciben Inhibidores de la Proteasa (IP). Material y métodos. Estudio descriptivo, transversal. Muestra: 92 pacientes mujeres con VIH bajo tratamiento antirretroviral, que son asistidas en el Instituto Centralizado de Asistencia e Investigación Clínica Integral (CAICI). Instrumento: Se les realizó una encuesta que consta de características demográficas, preguntas referidas al VIH y al The Female Sexual Function Index (FSFI). Análisis estadístico: se utilizó ANOVA, Kruskall-Wallis, Chi cuadrado, regresión logística y alpha de Cronbach. Resultados. Edad media: 42±10 años; 65% tenían pareja estable, siendo el 73% de estas sero-discordantes. La mayoría (45,7%) estaban en tratamiento antirretroviral por más de dos años, con una media de CD4 mayor a 500 cél/ml y el 90% con carga viral plasmática indetectable. El 64,1% presentaba otra enfermedad asociada, por lo que el 55,4% tomaba medicación concomitante. El 27,2% continuó con su actividad sexual luego del diagnóstico de VIH, pero el 26,1% nunca la retomó. La puntuación total alcanzada por medio del FSFI fue de 20,4±10,1 para las tratadas con IP y 20±10,6 para las tratadas con INNTI (p <0,005). Conclusiones. La muestra analizada presentó un puntaje compatible con disfunción sexual. No hubo diferencia estadísticamente significativa en la función sexual de las mujeres tratadas con IP y las tratadas con INNTI

Summary Objective: To describe the sexual function in a group of women with HIV on antiretroviral treatment. To assess whether there is a difference between those treated with Non-nucleoside Inhibitors of he Reverse Transcriptase (NNRTI) and those receiving protease inhibitors (PIs). Material and methods: Descriptive, transversal study. Study sample: 92 women with HIV on antiretroviral therapy who are assisted in the Central Institute of Integral Assistance and Clinical Research (CAICI). Instrument: They completed a survey consisting of questions about demographic characteristics, HIV, and The Female Sexual Function Index (FSFI). Statistical analysis: ANOVA, Kruskal-Wallis, Chi-square, logistic regression and Cronbach’s alpha. Results: Average age was 42±10 years; 65% had a steady partner, of which 73% were sero-discordant. Most patients (45.7%) had been on antiretroviral treatment for more than two years, with a mean CD4 greater than 500 cells/ml and 90% with undetectable plasma viral load. Other illnesses were present in 64.1%, and 55.4% were taking concomitant medication. Sexual activity after HIV diagnosis was continued by 27.2%, while 26.1% never resumed it. The total score achieved by the FSFI was 20.4±10.1 among those treated with IP and 20.0±10.6 among those treated with NNRTI(p<0.005). Conclusions: The score in the present sample supports the existence of sexual dysfunction. There was no statistically significant difference in the sexual function of women treated with either PI or NNRTI

Impacto del tratamiento antirretroviral en la función sexual de mujeres con VIH / Impact of antiretroviral treatment on sexual function of HIV-infected women

Objetivo. Describir la función sexual de un grupo de mujeres con VIH bajo tratamiento antirretroviral. Evaluar si existe diferencia entre las tratadas con un esquema que contiene Inhibidores No Nucleósidos de la Transcriptasa Inversa (INNTI) y aquéllas que reciben Inhibidores de la Proteasa (IP). Material y métodos. Estudio descriptivo, transversal. Muestra: 92 pacientes mujeres con VIH bajo tratamiento antirretroviral, que son asistidas en el Instituto Centralizado de Asistencia e Investigación Clínica Integral (CAICI). Instrumento: Se les realizó una encuesta que consta de características demográficas, preguntas referidas al VIH y al The Female Sexual Function Index (FSFI). Análisis estadístico: se utilizó ANOVA, Kruskall-Wallis, Chi cuadrado, regresión logística y alpha de Cronbach. Resultados. Edad media: 42±10 años; 65% tenían pareja estable, siendo el 73% de estas sero-discordantes. La mayoría (45,7%) estaban en tratamiento antirretroviral por más de dos años, con una media de CD4 mayor a 500 cél/ml y el 90% con carga viral plasmática indetectable. El 64,1% presentaba otra enfermedad asociada, por lo que el 55,4% tomaba medicación concomitante. El 27,2% continuó con su actividad sexual luego del diagnóstico de VIH, pero el 26,1% nunca la retomó. La puntuación total alcanzada por medio del FSFI fue de 20,4±10,1 para las tratadas con IP y 20±10,6 para las tratadas con INNTI (p <0,005). Conclusiones. La muestra analizada presentó un puntaje compatible con disfunción sexual. No hubo diferencia estadísticamente significativa en la función sexual de las mujeres tratadas con IP y las tratadas con INNTI(AU)

Summary Objective: To describe the sexual function in a group of women with HIV on antiretroviral treatment. To assess whether there is a difference between those treated with Non-nucleoside Inhibitors of he Reverse Transcriptase (NNRTI) and those receiving protease inhibitors (PIs). Material and methods: Descriptive, transversal study. Study sample: 92 women with HIV on antiretroviral therapy who are assisted in the Central Institute of Integral Assistance and Clinical Research (CAICI). Instrument: They completed a survey consisting of questions about demographic characteristics, HIV, and The Female Sexual Function Index (FSFI). Statistical analysis: ANOVA, Kruskal-Wallis, Chi-square, logistic regression and CronbachÆs alpha. Results: Average age was 42±10 years; 65% had a steady partner, of which 73% were sero-discordant. Most patients (45.7%) had been on antiretroviral treatment for more than two years, with a mean CD4 greater than 500 cells/ml and 90% with undetectable plasma viral load. Other illnesses were present in 64.1%, and 55.4% were taking concomitant medication. Sexual activity after HIV diagnosis was continued by 27.2%, while 26.1% never resumed it. The total score achieved by the FSFI was 20.4±10.1 among those treated with IP and 20.0±10.6 among those treated with NNRTI(p<0.005). Conclusions: The score in the present sample supports the existence of sexual dysfunction. There was no statistically significant difference in the sexual function of women treated with either PI or NNRTI(AU)

Drug-resistance development differs between HIV-1-infected patients failing first-line antiretroviral therapy containing nonnucleoside reverse transcriptase inhibitors with and without thymidine analogues.

OBJECTIVES: We evaluated the emergence of drug resistance in patients failing first-line regimens containing one nonnucleoside reverse transcriptase inhibitor (NNRTI) administered with zidovudine (ZDV) + lamivudine (the ZDV group) or non-thymidine analogues (non-TAs) (tenofovir or abacavir, + lamivudine or emtricitabine; the non-TA group). METHODS: Three hundred HIV-1-infected patients failing a first-line NNRTI-containing regimen (nevirapine, n = 148; efavirenz, n = 152) were included in the analysis. Virological failure was defined as viraemia ≥ 400 HIV-1 RNA copies/mL for the first time at least 6 months after starting the NNRTI-based regimen. For each patient, a genotypic resistance test at failure was available. The presence of drug-resistance mutations in HIV-1 reverse transcriptase was evaluated by comparing patients treated with NNRTI + zidovudine + lamivudine vs. those treated with NNRTI + non-TA. RESULTS: A total of 208 patients were failing with NNRTI + zidovudine + lamivudine and 92 with NNRTI + non-TA. No significant differences were observed between the non-TA group and the ZDV group regarding the time of virological failure [median (interquartile range): 12 (8-25) vs. 13 (9-32) months, respectively; P = 0.119] and viraemia [median (interquartile range): 4.0 (3.2-4.9) vs. 4.0 (3.3-4.7) log10 copies/mL, respectively; P = 0.894]. Resistance to reverse transcriptase inhibitors (RTIs) occurred at a significant lower frequency in the non-TA group than in the ZDV group (54.3 vs. 75.5%, respectively; P = 0.001). This difference was mainly attributable to a significantly lower prevalence of NNRTI resistance (54.3 vs. 74.0%, respectively; P = 0.002) and of the nucleoside reverse transcriptase inhibitor (NRTI) mutation M184V (23.9 vs. 63.5%, respectively; P < 0.001) in the non-TA group compared with the ZDV group. As expected, the mutation K65R was found only in the non-TA group (18.5%; P < 0.001). CONCLUSIONS: At first-line regimen failure, a lower prevalence of RTI resistance was found in patients treated with NNRTI + non-TA compared with those treated with NNRTI + zidovudine + lamivudine. These results confirm that the choice of backbone may influence the prevalence of drug resistance at virological failure.

A modified SILCS contraceptive diaphragm for long-term controlled release of the HIV microbicide dapivirine.

BACKGROUND: There is considerable interest in developing new multipurpose prevention technologies to address women's reproductive health needs. This study describes an innovative barrier contraceptive device--based on the SILCS diaphragm--that also provides long-term controlled release of the lead candidate anti-HIV microbicide dapivirine. STUDY DESIGN: Diaphragm devices comprising various dapivirine-loaded polymer spring cores overmolded with a nonmedicated silicone elastomer sheath were fabricated by injection molding processes. In vitro release testing, thermal analysis and mechanical characterization were performed on the devices. RESULTS: A diaphragm device containing a polyoxymethylene spring core loaded with 10% w/w dapivirine provided continuous and controlled release of dapivirine over a 6-month period, with a mean in vitro daily release rate of 174 mcg/day. The mechanical properties of the new diaphragm were closely matched to the SILCS diaphragm. CONCLUSIONS: The study demonstrates proof of concept for a dapivirine-releasing diaphragm with daily release quantities potentially capable of preventing HIV transmission. In discontinuous clinical use, release of dapivirine may be readily extended over 1 or more years.

[The newest developments in anti-HIV-1 drugs].

In the two decades since AZT was first approved for clinical use in 1987, 24 additional antiretroviral agents have been approved. They include 7 nucleoside analogs, a nucleotide analog and 4 non-nucleoside reverse transcriptase inhibitors, 10 protease inhibitors, 2 entry inhibitors and an integrase inhibitor. More than 20 investigational agents are currently being studied in clinical trials. Highly active antiretroviral therapy (HAART), which involves a combination of anti-HIV-1 drugs, is extremely effective in suppressing HIV-1 replication and increasing CD4+ number and results in substantial reductions in HIV-1-related morbidity and mortality. In last 20 years, much has been learned about resistance to antiretroviral drugs, drug interactions and metabolic complications of antiviral drug use. Drugs are now selected on the basis of resistance tests and on the risk of specific drug complications in individual patients. As a result, decisions about the therapy of HIV/AIDS have become personalized and are made on a patient-by-patient basis. With appropriate medical management, a person with HIV-1 now has the possibility of a nearly normal life expectancy.