NOVA2 regulates neural circRNA biogenesis

Circular RNAs (circRNAs) are highly expressed in the brain and their expression increases during neuronal differentiation. The factors regulating circRNAs in the developing mouse brain are unknown. NOVA1 and NOVA2 are neural-enriched RNA-binding proteins with well-characterized roles in alternative splicing. Profiling of circRNAs from RNA-seq data revealed that global circRNA levels were reduced in embryonic cortex of Nova2 but not Nova1 knockout mice. Analysis of isolated inhibitory and excitatory cortical neurons lacking NOVA2 revealed an even more dramatic reduction of circRNAs and establishes a widespread role for NOVA2 in enhancing circRNA biogenesis. To investigate the cis-elements controlling NOVA2-regulation of circRNA biogenesis, we generated a backsplicing reporter based on the Efnb2 gene. We found that NOVA2-mediated backsplicing of circEfnb2 was impaired when YCAY clusters located in flanking introns were mutagenized. CLIP (cross-linking and immunoprecipitation) and additional reporter analyses demonstrated the importance of NOVA2 binding sites located in both flanking introns of circRNA loci. NOVA2 is the first RNA-binding protein identified to globally promote circRNA biogenesis in the developing brain.

Physiologic RNA targets and refined sequence specificity of coronavirus EndoU

Coronavirus EndoU inhibits dsRNA-activated antiviral responses; however, the physiologic RNA substrates of EndoU are unknown. In this study, we used mouse hepatitis virus (MHV)-infected bone marrow-derived macrophage (BMM) and cyclic phosphate cDNA sequencing to identify the RNA targets of EndoU. EndoU targeted viral RNA, cleaving the 3' side of pyrimidines with a strong preference for U ↓ A and C ↓ A sequences (endoY ↓ A). EndoU-dependent cleavage was detected in every region of MHV RNA, from the 5' NTR to the 3' NTR, including transcriptional regulatory sequences (TRS). Cleavage at two CA dinucleotides immediately adjacent to the MHV poly(A) tail suggests a mechanism to suppress negative-strand RNA synthesis and the accumulation of viral dsRNA. MHV with EndoU (EndoUmut) or 2'-5' phosphodiesterase (PDEmut) mutations provoked the activation of RNase L in BMM, with corresponding cleavage of RNAs by RNase L. The physiologic targets of EndoU are viral RNA templates required for negative-strand RNA synthesis and dsRNA accumulation. Coronavirus EndoU cleaves U ↓ A and C ↓ A sequences (endoY ↓ A) within viral (+) strand RNA to evade dsRNA-activated host responses.

Cardiovascular disease and diabetes in HIV-positive and HIV-negative gay and bisexual men over the age of 55 years in Australia: insights from the Australian Positive & Peers Longevity Evaluation Study

OBJECTIVES

As HIV-positive people age, diagnosis and management of comorbidities associated with ageing are of increasing concern. In this study, we aimed to compare the self-reported prevalences of heart disease, stroke, thrombosis and diabetes in older Australian HIV-positive and HIV-negative gay and bisexual men (GBM).

METHODS

We analysed data from the Australian Positive & Peers Longevity Evaluation Study (APPLES), a study of a prospectively recruited cross-sectional sample of 228 (51.1%) HIV-positive and 218 (48.9%) HIV-negative GBM, aged ≥ 55 years. Regression methods were used to assess the association of HIV status with self-reported comorbidities.

RESULTS

Of 446 patients, 389 [200 (51.4%) HIV-positive] reported their disease history. The reported prevalence of comorbidities was higher in the HIV-positive group than in the HIV-negative group: heart disease, 19.5 versus 12.2%; stroke, 7.5 versus 4.2%; thrombosis, 10.5 versus 4.2%; and diabetes, 15.0 versus 9.0%, respectively. In adjusted analyses, HIV-positive GBM had significantly increased odds of reporting heart disease [adjusted odds ratio (aOR) 1.99; P = 0.03] and thrombosis (aOR 2.87; P = 0.01). In our analysis, HIV status was not significantly associated with either age at diagnosis of heart disease (median 53 years for HIV-positive GBM versus 55 years for HIV-negative GBM; P = 0.64) or 5-year cardiovascular disease (CVD) risk estimated using the Framingham risk score.

CONCLUSIONS

HIV-positive GBM more commonly reported heart disease and thrombosis compared with their HIV-negative peers. These results further highlight the need to understand the impact of HIV on age-related comorbidities in GBM, to guide optimal screening and treatment strategies to reduce the risk of these comorbidities among the HIV-positive population.

Global accumulation of circRNAs during aging in Caenorhabditis elegans

Background

Circular RNAs (CircRNAs) are a newly appreciated class of RNAs that lack free 5′ and 3′ ends, are expressed by the thousands in diverse forms of life, and are mostly of enigmatic function. Ostensibly due to their resistance to exonucleases, circRNAs are known to be exceptionally stable. Previous work in Drosophila and mice have shown that circRNAs increase during aging in neural tissues.

Results

Here, we examined the global profile of circRNAs in C. elegans during aging by performing ribo-depleted total RNA-seq from the fourth larval stage (L4) through 10-day old adults. Using stringent bioinformatic criteria and experimental validation, we annotated a high-confidence set of 1166 circRNAs, including 575 newly discovered circRNAs. These circRNAs were derived from 797 genes with diverse functions, including genes involved in the determination of lifespan. A massive accumulation of circRNAs during aging was uncovered. Many hundreds of circRNAs were significantly increased among the aging time-points and increases of select circRNAs by over 40-fold during aging were quantified by RT-qPCR. The expression of 459 circRNAs was determined to be distinct from the expression of linear RNAs from the same host genes, demonstrating host gene independence of circRNA age-accumulation.

Conclusions

We attribute the global scale of circRNA age-accumulation to the high composition of post-mitotic cells in adult C. elegans, coupled with the high resistance of circRNAs to decay. These findings suggest that the exceptional stability of circRNAs might explain age-accumulation trends observed from neural tissues of other organisms, which also have a high composition of post-mitotic cells. Given the suitability of C. elegans for aging research, it is now poised as an excellent model system to determine whether there are functional consequences of circRNA accumulation during aging.

Electronic supplementary material

The online version of this article (10.1186/s12864-017-4386-y) contains supplementary material, which is available to authorized users.

Genome-Wide circRNA Profiling from RNA-seq Data

The genome-wide expression patterns of circular RNAs (circRNAs) are of increasing interest for their potential roles in normal cellular homeostasis, development, and disease. Thousands of circRNAs have been annotated from various species in recent years. Analysis of publically available or user-generated rRNA-depleted total RNA-seq data can be performed to uncover new circRNA expression trends. Here we provide a primer for profiling circRNAs from RNA-seq datasets. The description is tailored for the wet lab scientist with limited or no experience in analyzing RNA-seq data. We begin by describing how to access and interpret circRNA annotations. Next, we cover converting circRNA annotations into junction sequences that are used as scaffolds to align RNA-seq reads. Lastly, we visit quantifying circRNA expression trends from the alignment data.

Transcriptome profiling of aging Drosophila photoreceptors reveals gene expression trends that correlate with visual senescence

BACKGROUND

Aging is associated with functional decline of neurons and increased incidence of both neurodegenerative and ocular disease. Photoreceptor neurons in Drosophila melanogaster provide a powerful model for studying the molecular changes involved in functional senescence of neurons since decreased visual behavior precedes retinal degeneration. Here, we sought to identify gene expression changes and the genomic features of differentially regulated genes in photoreceptors that contribute to visual senescence.

RESULTS

To identify gene expression changes that could lead to visual senescence, we characterized the aging transcriptome of Drosophila sensory neurons highly enriched for photoreceptors. We profiled the nuclear transcriptome of genetically-labeled photoreceptors over a 40 day time course and identified increased expression of genes involved in stress and DNA damage response, and decreased expression of genes required for neuronal function. We further show that combinations of promoter motifs robustly identify age-regulated genes, suggesting that transcription factors are important in driving expression changes in aging photoreceptors. However, long, highly expressed and heavily spliced genes are also more likely to be downregulated with age, indicating that other mechanisms could contribute to expression changes at these genes. Lastly, we identify that circular RNAs (circRNAs) strongly increase during aging in photoreceptors.

CONCLUSIONS

Overall, we identified changes in gene expression in aging Drosophila photoreceptors that could account for visual senescence. Further, we show that genomic features predict these age-related changes, suggesting potential mechanisms that could be targeted to slow the rate of age-associated visual decline.

Comparison of Kaposi Sarcoma Risk in Human Immunodeficiency Virus-Positive Adults Across 5 Continents: A Multiregional Multicohort Study

BACKGROUND

We compared Kaposi sarcoma (KS) risk in adults who started antiretroviral therapy (ART) across the Asia-Pacific, South Africa, Europe, Latin, and North America.

METHODS

We included cohort data of human immunodeficiency virus (HIV)-positive adults who started ART after 1995 within the framework of 2 large collaborations of observational HIV cohorts. We present incidence rates and adjusted hazard ratios (aHRs).

RESULTS

We included 208140 patients from 57 countries. Over a period of 1066572 person-years, 2046 KS cases were diagnosed. KS incidence rates per 100000 person-years were 52 in the Asia-Pacific and ranged between 180 and 280 in the other regions. KS risk was 5 times higher in South African women (aHR, 4.56; 95% confidence intervals [CI], 2.73-7.62) than in their European counterparts, and 2 times higher in South African men (2.21; 1.34-3.63). In Europe, Latin, and North America KS risk was 6 times higher in men who have sex with men (aHR, 5.95; 95% CI, 5.09-6.96) than in women. Comparing patients with current CD4 cell counts ≥700 cells/µL with those whose counts were <50 cells/µL, the KS risk was halved in South Africa (aHR, 0.53; 95% CI, .17-1.63) but reduced by ≥95% in other regions.

CONCLUSIONS

Despite important ART-related declines in KS incidence, men and women in South Africa and men who have sex with men remain at increased KS risk, likely due to high human herpesvirus 8 coinfection rates. Early ART initiation and maintenance of high CD4 cell counts are essential to further reducing KS incidence worldwide, but additional measures might be needed, especially in Southern Africa.

A longitudinal cohort study of HIV 'treatment as prevention' in gay, bisexual and other men who have sex with men: the Treatment with Antiretrovirals and their Impact on Positive And Negative men (TAIPAN) study protocol

BACKGROUND

Australia has increased coverage of antiretroviral treatment (ART) over the past decade, reaching 73% uptake in 2014. While ART reduces AIDS-related deaths, accumulating evidence suggests that it could also bolster prevention efforts by reducing the risk of HIV transmission ('treatment as prevention'). While promising, evidence of community-level impact of treatment as prevention on reducing HIV incidence among gay and bisexual men is limited. We describe a study protocol that aims to determine if scale up of testing and treatment for HIV leads to a reduction in community viraemia and, in turn, if this reduction is temporally associated with a reduction in HIV incidence among gay and bisexual men in Australia's two most populous states.

METHODS

Over the period 2009 to 2017, we will establish two cohorts making use of clinical and laboratory data electronically extracted retrospectively and prospectively from 73 health services and laboratories in the states of New South Wales and Victoria. The 'positive cohort' will consist of approximately 13,000 gay and bisexual men (>90% of all people living with HIV). The 'negative cohort' will consist of at least 40,000 HIV-negative gay and bisexual men (approximately half of the total population). Within the negative cohort we will use standard repeat-testing methods to calculate annual HIV incidence. Community prevalence of viraemia will be defined as the proportion of men with a viral load ≥200RNA copies/mm³, which will combine viral load data from the positive cohort and viraemia estimates among those with an undiagnosed HIV infection. Using regression analyses and adjusting for behavioural and demographic factors associated with infection, we will assess the temporal association between the community prevalence of viraemia and the incidence of HIV infection. Further analyses will make use of these cohorts to assess incidence and predictors of treatment initiation, repeat HIV testing, and viral suppression.

DISCUSSION

This study will provide important information on whether 'treatment as prevention' is associated with a reduction in HIV incidence at a community level among gay and bisexual men.

Pharmacokinetic and Pharmacodynamic Comparison of Once-Daily Efavirenz (400 mg vs. 600 mg) in Treatment-Naïve HIV-Infected Patients: Results of the ENCORE1 Study

Daily efavirenz 400 mg (EFV400) was virologically noninferior to 600 mg (EFV600) at 48 weeks in treatment‐naïve patients. We evaluated EFV400 and EFV600 pharmacokinetics (NONMEM v. 7.2), assessing patient demographics and genetic polymorphisms (CYP2B6, CYP2A6, CYP3A4, NR1I3) as covariates and explored relationships with efficacy (plasma HIV‐RNA (pVL) <200 copies/mL) and safety outcomes at 48 weeks in 606 randomized ENCORE1 patients (female = 32%, African = 37%, Asian = 33%; EFV400 = 311, EFV600 = 295). CYP2B6 516G>T/983T>C/CYP2A6*9B/*17 and weight were associated with efavirenz CL/F. Exposure was significantly lower for EFV400 (geometric mean ratio, GMR; 90% confidence interval, CI: 0.73 (0.68–0.78)) but 97% (EFV400) and 98% (EFV600) of evaluable pVL was <200 copies/mL at 48 weeks (P = 0.802). Four of 20 patients with mid‐dose concentrations <1.0 mg/L had pVL ≥200 copies/mL (EFV400 = 1; EFV600 = 3). Efavirenz exposure was similar between those with and without efavirenz‐related side effects (GMR; 90% CI: 0.95 (0.88–1.02)). HIV suppression was comparable between doses despite significantly lower EFV400 exposure. Comprehensive evaluation of efavirenz pharmacokinetics/pharmacodynamics revealed important limitations in the accepted threshold concentration.

Ribonuclease L and metal-ion-independent endoribonuclease cleavage sites in host and viral RNAs

Ribonuclease L (RNase L) is a metal-ion–independent endoribonuclease associated with antiviral and antibacterial defense, cancer and lifespan. Despite the biological significance of RNase L, the RNAs cleaved by this enzyme are poorly defined. In this study, we used deep sequencing methods to reveal the frequency and location of RNase L cleavage sites within host and viral RNAs. To make cDNA libraries, we exploited the 2′, 3′-cyclic phosphate at the end of RNA fragments produced by RNase L and other metal-ion–independent endoribonucleases. We optimized and validated 2′, 3′-cyclic phosphate cDNA synthesis and Illumina sequencing methods using viral RNAs cleaved with purified RNase L, viral RNAs cleaved with purified RNase A and RNA from uninfected and poliovirus-infected HeLa cells. Using these methods, we identified (i) discrete regions of hepatitis C virus and poliovirus RNA genomes that were profoundly susceptible to RNase L and other single-strand specific endoribonucleases, (ii) RNase L-dependent and RNase L-independent cleavage sites within ribosomal RNAs (rRNAs) and (iii) 2′, 3′-cyclic phosphates at the ends of 5S rRNA and U6 snRNA. Monitoring the frequency and location of metal-ion–independent endoribonuclease cleavage sites within host and viral RNAs reveals, in part, how these enzymes contribute to health and disease.

Ritonavir-boosted lopinavir plus nucleoside or nucleotide reverse transcriptase inhibitors versus ritonavir-boosted lopinavir plus raltegravir for treatment of HIV-1 infection in adults with virological failure of a standard first-line ART regimen (SECOND-LINE): a randomised, open-label, non-inferiority study

BACKGROUND

Uncertainty exists about the best treatment for people with HIV-1 who have virological failure with first-line combination antiretroviral therapy of a non-nucleoside analogue (NNRTI) plus two nucleoside or nucleotide analogue reverse transcriptase inhibitors (NtRTI). We compared a second-line regimen combining two new classes of drug with a WHO-recommended regimen.

METHODS

We did this 96-week, phase 3b/4, randomised, open-label non-inferiority trial at 37 sites worldwide. Adults with HIV-1 who had confirmed virological failure (plasma viral load >500 copies per mL) after 24 weeks or more of first-line treatment were randomly assigned (1:1) to receive ritonavir-boosted lopinavir plus two or three NtRTIs (control group) or ritonavir-boosted lopinavir plus raltegravir (raltegravir group). The randomisation sequence was computer generated with block randomisation (block size four). Neither participants nor investigators were masked to allocation. The primary endpoint was the proportion of participants with plasma viral load less than 200 copies per mL at 48 weeks in the modified intention-to-treat population, with a non-inferiority margin of 12%. This study is registered with ClinicalTrials.gov, number NCT00931463.

FINDINGS

We enrolled 558 patients, of whom 541 (271 in the control group, 270 in the raltegravir group) were included in the primary analysis. At 48 weeks, 219 (81%) patients in the control group compared with 223 (83%) in the raltegravir group met the primary endpoint (difference 1·8%, 95% CI -4·7 to 8·3), fulfilling the criterion for non-inferiority. 993 adverse events occurred in 271 participants in the control group versus 895 in 270 participants in the raltegravir group, the most common being gastrointestinal.

INTERPRETATION

The raltegravir regimen was no less efficacious than the standard of care and was safe and well tolerated. This simple NtRTI-free treatment strategy might extend the successful public health approach to management of HIV by providing simple, easy to administer, effective, safe, and tolerable second-line combination antiretroviral therapy.

FUNDING

University of New South Wales, Merck, AbbVie, the Foundation for AIDS Research.

The 2010 Royal Australasian College of Physicians' policy statement 'Circumcision of infant males' is not evidence based

Infant male circumcision (MC) is an important issue guided by Royal Australasian College of Physicians (RACP) policy. Here we analytically review the RACP's 2010 policy statement 'Circumcision of infant males'. Comprehensive evaluation in the context of published research was used. We find that the Statement is not a fair and balanced representation of the literature on MC. It ignores, downplays, obfuscates or misrepresents the considerable evidence attesting to the strong protection MC affords against childhood urinary tract infections, sexually transmitted infections (human immunodeficiency virus, human papilloma virus, herpes simplex virus type 2, trichomonas and genital ulcer disease), thrush, inferior penile hygiene, phimosis, balanoposthitis and penile cancer, and in women protection against human papilloma virus, herpes simplex virus type 2, bacterial vaginosis and cervical cancer. The Statement exaggerates the complication rate. Assertions that 'the foreskin has a functional role' and 'is a primary sensory part of the penis' are not supported by research, including randomised controlled trials. Instead of citing these and meta-analyses, the Statement selectively cites poor quality studies. Its claim, without support from a literature-based risk-benefit analysis, that the currently available evidence does 'not warrant routine infant circumcision in Australia and New Zealand' is misleading. The Statement fails to explain that performing MC in the neonatal period using local anaesthesia maximises benefits, safety, convenience and cost savings. Because the RACP's policy statement is not a fair and balanced representation of the current literature, it should not be used to guide policy. In the interests of public health and individual well-being, an extensive, comprehensive, balanced review of the scientific literature and a risk-benefit analysis should be conducted to formulate policy.

Assessing adherence in Thai patients taking combination antiretroviral therapy

In settings where medications and viral load (VL) monitoring are limited by cost, clinicians need reliable ways to assess patient adherence to therapy. We assessed sensitivity and specificity of two self-reported adherence tools (a visual analogue scale [VAS] and the CASE [Center for Adherence Support Evaluation] adherence index), against a standard of detectable VL, with 288 patients from three sites in Thailand. We also assessed predictors of non-adherence. The sensitivity and specificity of the VAS <95% and CASE adherence index ≤11 against a VL >50 copies/mL were 26% and 90%, 19% and 95%, respectively. Against a VL ≥1000 copies/mL sensitivities increased to 55% and 36%, respectively, and specificities were unchanged. Attending a clinic not staffed by HIV specialists (odds ratio [OR] 3.14; 95% confidence interval [CI] 1.19-8.34) and being educated to primary school level or less (OR 2.24; 95% CI 1.01-4.94) were associated with self-reported adherence <95% on the VAS in multivariate analysis. Adherence assessed by the VAS was a more accurate predictor of detectable VL. Policy-makers in resource-limited settings should ensure that treatment centres are staffed with well-trained personnel aware of the importance of good patient adherence.

Dynamics of cognitive change in HIV-infected individuals commencing three different initial antiretroviral regimens: a randomized, controlled study

BACKGROUND

Improvements in neurocognitive (NC) function have been associated with commencing antiretroviral therapy in HIV-infected subjects. However, the dynamics of such improvements are poorly understood.

METHODS

We assessed changes in NC function via a validated computerized battery (CogState™, Melbourne, Victoria, Australia) at baseline and after 24 and 48 weeks in a subset of therapy-naïve neuro-asymptomatic HIV-infected subjects, randomized to commence three different antiretroviral regimens.

RESULTS

Of 28 subjects enrolled in the study, nine, eight and 11 were randomly allocated to commence tenofovir/emtricitabine with efavirenz (arm 1), atazanavir/ritonavir (arm 2) and zidovudine/abacavir (arm 3), respectively. Overall improvements in NC function were observed at week 24 and function continued to improve at week 48 (changes in z-score for overall cognitive global score of 0.16 and 0.18 at weeks 24 and 48, respectively). Within the NC speed domains, generally greater improvements were observed in arms 2 and 3, compared with arm 1 (changes in z-score for composite speed scores at weeks 24/48 of 0.16/0.16, -0.29/-0.24 and -0.15/-0.31 in arms 1, 2 and 3, respectively; P = 0.04 for change at week 48 in arm 3 versus arm 1). Finally, improvements in executive function occurred later (only observed at week 48) and were driven by improvements in arm 3 (z-score changes of 0.23, 0.06 and -0.78 in arms 1, 2 and 3, respectively; P = 0.02 for change in arm 3 versus arm 1).

CONCLUSION

Improvements in NC function continue over the first year after initiating antiretroviral therapy in neuro-asymptomatic HIV-infected subjects.

Genital shedding of HIV after scheduled treatment interruption

This study assessed genital shedding of HIV in patients on intermittent combination antiretroviral therapy (cART) and assessed predictors of having detectable genital HIV RNA in 156 Thai patients with CD4 > 350 cells/μL and HIV RNA ≤50 copies/mL who were randomized to continuous therapy (CT, n = 65) or CD4-guided cART (n = 91). There were 383 matched genital and plasma HIV RNA samples (CT: 158, CD4 guided: 225). In 14 samples collected within eight weeks of treatment interruption, detectable HIV RNA was present in 29% of genital samples and 71% of plasma samples. In 55 samples collected after eight weeks of treatment interruption, detectable HIV RNA was present in 60% of genital samples and 98% of plasma samples. In 110 samples collected up to 96 weeks after treatment re-initiation, detectable genital HIV RNA was found in 8% of samples and all of these were within the first 17 weeks. Independent predictors of detectable genital HIV RNA were increasing age and increasing concentrations of HIV RNA in plasma. These findings support the role of cART in maintaining undetectable HIV RNA in genital secretions.

Hyperlactataemia in HIV-infected subjects initiating antiretroviral therapy in a large randomized study (a substudy of the INITIO trial)

OBJECTIVE

The aim of the study was to evaluate the predictive value of clinical and molecular risk factors, including peripheral blood mononuclear cell (PBMC) mitochondrial DNA (mtDNA) and mitochondrial RNA (mtRNA), for the development of lactic acidosis (LA) and symptomatic hyperlactataemia (SHL).

METHODS

In a substudy of a large multicentre, randomized trial of three antiretroviral regimens, all containing didanosine (ddI) and stavudine (d4T), in antiretroviralnaïve, HIV-1-infected patients, patients with LA/SHL ('cases') were compared with those without LA/SHL in a univariate analysis, with significant parameters analysed in a multivariate model. In a molecular substudy, PBMC mtDNA and mtRNA from cases and matched controls at baseline and time of event were examined.

RESULTS

In 911 subjects followed for a median of 192 weeks, 24 cases were identified (14 SHL and 10 LA). In univariate analysis, cases were more likely to be female (P=0.05) and to have a high body mass index (BMI) (P=0.02). In multivariate analyses, only BMI remained an independent predictor of the development of LA/SHL (P=0.03). Between cases and controls there was no significant difference in mtDNA copy number at baseline (389 vs. 411 copies/cell, respectively; P=0.60) or at time of event (329 vs. 474 copies/cell, respectively; P=0.21), in the change in mtDNA copy number from baseline to event (-65 vs. +113 copies/cell, respectively; P=0.12), in mtRNA expression at baseline or time of event, or in the change in mtRNA expression from baseline to event.

CONCLUSION

The development of LA/SHL was associated with increased BMI, but PBMC mtDNA and mtRNA did not predict LA/SHL. This demonstrates the ineffectiveness of routine measurement of PBMC mtDNA in patients on ddI and d4T as a means of predicting development of LA/SHL.

The effects of enfuvirtide therapy on body composition and metabolic parameters over 48 weeks in the TORO body imaging substudy

OBJECTIVE

The aim of the study was to compare the metabolic and morphological effects of enfuvirtide plus an optimized background (OB) regimen vs. OB alone (control group) in treatment-experienced patients in the T-20 vs. Optimized Regimen Only (TORO) studies.

METHODS

Body composition and metabolic changes were investigated in patients over 48 weeks, based on fasting chemistries, body weight, and other anthropometric measurements. Dual-energy X-ray absorptiometry (DEXA) and computed tomography (CT) scans were performed in a patient subgroup (n=155) at baseline and at weeks 24 and 48.

RESULTS

At week 48, mean changes from baseline were similar between treatment groups for glucose, insulin, C-peptide, total cholesterol, low-density lipoprotein (LDL) cholesterol, very low density lipoprotein (VLDL) cholesterol, high-density lipoprotein (HDL) cholesterol and triglyceride levels. The enfuvirtide group experienced a significant increase in body weight [mean change from baseline +0.99 kg; 95% confidence interval (CI) +0.54, +1.44] and, in those who had body scans, there was a significant increase in truncal fat (by DEXA: median change +419.4 g; 95% CI+71.3, +767.5) and total fat [visceral adipose tissue (VAT)+subcutaneous adipose tissue (SAT) by single-slice abdominal CT scan: median change +25.5 cm(2) ; 95% CI+8.9, +42.0] over 48 weeks; significant increases in these parameters were not seen in the control group. There was no significant change in truncal:peripheral fat ratio in either the enfuvirtide or the control group.

CONCLUSION

The addition of enfuvirtide to an OB regimen does not appear to have unfavourable effects on fat distribution or metabolic parameters.

Antiviral activity of apricitabine in treatment-experienced HIV-1-infected patients with M184V who are failing combination therapy

OBJECTIVES

Apricitabine (ATC) is a novel deoxycytidine analogue nucleoside reverse transcriptase inhibitor (NRTI) with significant antiviral activity in vitro, including activity against HIV-1 with reverse transcriptase mutations that confer resistance to other NRTIs. ATC has shown promising antiviral activity and good tolerability when given as monotherapy for 10 days in treatment-naïve HIV-1-infected patients.

METHODS

In this Phase II randomized, double-blind study, 51 treatment-experienced HIV-1-infected patients with the reverse transcriptase mutation M184V who were failing therapy which included lamivudine (3TC) were randomized to receive twice-daily 600 mg ATC, 800 mg ATC or 150 mg 3TC for 21 days. Patients remained on their existing background regimen until day 21, when background therapy could be optimized according to genotype at screening.

RESULTS

At day 21, the mean change in viral load was -0.71 and -0.90 log(10) HIV-1 RNA copies/mL in the 600 and 800 mg ATC groups, respectively, compared with a -0.03 log(10) change in the 3TC group. In patients with at least three thymidine analogue mutations (TAMs) at baseline, greater reductions in viral load were observed in the 800 mg ATC group at day 21 than in the 600 mg ATC group. Few genotypic changes were detected at day 21 [two patients (600 mg ATC) lost and three patients (800 mg ATC) gained a TAM] and all patients with detectable virus retained the M184V mutation. The safety profiles of the two ATC doses were similar to that of 3TC.

CONCLUSIONS

Over the 21-day treatment period, ATC showed promising antiviral activity and was well tolerated in treatment-experienced patients with M184V, with or without additional TAMs.

Predictors of bacterial pneumonia in Evaluation of Subcutaneous Interleukin-2 in a Randomized International Trial (ESPRIT)

BACKGROUND AND OBJECTIVES

Bacterial pneumonia still contributes to morbidity/mortality in HIV infection despite effective combination antiretroviral therapy (cART). Evaluation of Subcutaneous Interleukin-2 in a Randomized International Trial (ESPRIT), a trial of intermittent recombinant interleukin-2 (rIL-2) with cART vs. cART alone (control arm) in HIV-infected adults with CD4 counts ≥300cells/μL, offered the opportunity to explore associations between bacterial pneumonia and rIL-2, a cytokine that increases the risk of some bacterial infections.

METHODS

Baseline and time-updated factors associated with first-episode pneumonia on study were analysed using multivariate proportional hazards regression models. Information on smoking/pneumococcal vaccination history was not collected.

RESULTS

IL-2 cycling was most intense in years 1-2. Over ≈7 years, 93 IL-2 [rate 0.67/100 person-years (PY)] and 86 control (rate 0.63/100 PY) patients experienced a pneumonia event [hazard ratio (HR) 1.06; 95% confidence interval (CI) 0.79, 1.42; P=0.68]. Median CD4 counts prior to pneumonia were 570cells/μL (IL-2 arm) and 463cells/μL (control arm). Baseline risks for bacterial pneumonia included older age, injecting drug use, detectable HIV viral load (VL) and previous recurrent pneumonia; Asian ethnicity was associated with decreased risk. Higher proximal VL (HR for 1 log(10) higher VL 1.28; 95% CI 1.11, 1.47; P<0.001) was associated with increased risk; higher CD4 count prior to the event (HR per 100 cells/μL higher 0.94; 95% CI 0.89, 1.0; P=0.04) decreased risk. Compared with controls, the hazard for a pneumonia event was higher if rIL-2 was received <180 days previously (HR 1.66; 95% CI 1.07, 2.60; P=0.02) vs.≥180 days previously (HR 0.98; 95% CI 0.70, 1.37; P=0.9). Compared with the control group, pneumonia risk in the IL-2 arm decreased over time, with HRs of 1.41, 1.71, 1.16, 0.62 and 0.84 in years 1, 2, 3-4, 5-6 and 7, respectively.

CONCLUSIONS

Bacterial pneumonia rates in cART-treated adults with moderate immunodeficiency are high. The mechanism of the association between bacterial pneumonia and recent IL-2 receipt and/or detectable HIV viraemia warrants further exploration.

No significant effect of uridine or pravastatin treatment for HIV lipoatrophy in men who have ceased thymidine analogue nucleoside reverse transcriptase inhibitor therapy: a randomized trial

BACKGROUND

Lipoatrophy can complicate thymidine analogue nucleoside reverse transcriptase inhibitor (tNRTI)-based antiretroviral therapy (ART). Lipoatrophy may be less likely with ART including ritonavir-boosted lopinavir (LPV/r). Small, placebo-controlled studies found that uridine (in tNRTI recipients) and pravastatin improved HIV lipoatrophy over 12 weeks. Today, most patients with lipoatrophy receive non-tNRTI-based ART; the effect of uridine in such patients is unknown.

METHODS

We performed a prospective, randomized trial in lipoatrophic adults with plasma HIV RNA<50 HIV-1 RNA copies/mL on tNRTI-sparing ART including LPV/r. Patients received uridine [36 g three times a day (tid) on 10 consecutive days per month; n=10], pravastatin [40 mg every night (nocte); n=12], uridine plus pravastatin (n=11) or neither (n=12) for 24 weeks. The primary endpoint was mean change in limb fat mass as assessed by dual-energy X-ray absorptiometry (DEXA). With 20 patients per intervention, the study had 80% power to detect a mean difference between a treatment and the control of 0.5 kg, assuming a standard deviation of 0.9 and an alpha threshold equal to 5% (two-sided).

RESULTS

Of 45 participants (all men, with median age 49.5 years and median limb fat 2.6 kg), two discontinued pravastatin and one participant stopped both pravastatin and uridine. The difference between the mean changes in limb fat mass for uridine vs. no uridine was 0.03 kg [95% confidence interval (CI) -0.35, +0.28; P=0.79]. The respective difference for pravastatin was -0.03 kg (95% CI -0.29, +0.34; P=0.84). Pravastatin slightly decreased total cholesterol (0.44 mmol/L; P=0.099). Visceral adipose tissue measured by computed tomography did not change significantly.

CONCLUSION

In this population and at the doses used, neither uridine nor pravastatin for 24 weeks significantly increased limb fat mass.

Interleukin-2 therapy in patients with HIV infection

BACKGROUND

Used in combination with antiretroviral therapy, subcutaneous recombinant interleukin-2 raises CD4+ cell counts more than does antiretroviral therapy alone. The clinical implication of these increases is not known.

METHODS

We conducted two trials: the Subcutaneous Recombinant, Human Interleukin-2 in HIV-Infected Patients with Low CD4+ Counts under Active Antiretroviral Therapy (SILCAAT) study and the Evaluation of Subcutaneous Proleukin in a Randomized International Trial (ESPRIT). In each, patients infected with the human immunodeficiency virus (HIV) who had CD4+ cell counts of either 50 to 299 per cubic millimeter (SILCAAT) or 300 or more per cubic millimeter (ESPRIT) were randomly assigned to receive interleukin-2 plus antiretroviral therapy or antiretroviral therapy alone. The interleukin-2 regimen consisted of cycles of 5 consecutive days each, administered at 8-week intervals. The SILCAAT study involved six cycles and a dose of 4.5 million IU of interleukin-2 twice daily; ESPRIT involved three cycles and a dose of 7.5 million IU twice daily. Additional cycles were recommended to maintain the CD4+ cell count above predefined target levels. The primary end point of both studies was opportunistic disease or death from any cause.

RESULTS

In the SILCAAT study, 1695 patients (849 receiving interleukin-2 plus antiretroviral therapy and 846 receiving antiretroviral therapy alone) who had a median CD4+ cell count of 202 cells per cubic millimeter were enrolled; in ESPRIT, 4111 patients (2071 receiving interleukin-2 plus antiretroviral therapy and 2040 receiving antiretroviral therapy alone) who had a median CD4+ cell count of 457 cells per cubic millimeter were enrolled. Over a median follow-up period of 7 to 8 years, the CD4+ cell count was higher in the interleukin-2 group than in the group receiving antiretroviral therapy alone--by 53 and 159 cells per cubic millimeter, on average, in the SILCAAT study and ESPRIT, respectively. Hazard ratios for opportunistic disease or death from any cause with interleukin-2 plus antiretroviral therapy (vs. antiretroviral therapy alone) were 0.91 (95% confidence interval [CI], 0.70 to 1.18; P=0.47) in the SILCAAT study and 0.94 (95% CI, 0.75 to 1.16; P=0.55) in ESPRIT. The hazard ratios for death from any cause and for grade 4 clinical events were 1.06 (P=0.73) and 1.10 (P=0.35), respectively, in the SILCAAT study and 0.90 (P=0.42) and 1.23 (P=0.003), respectively, in ESPRIT.

CONCLUSIONS

Despite a substantial and sustained increase in the CD4+ cell count, as compared with antiretroviral therapy alone, interleukin-2 plus antiretroviral therapy yielded no clinical benefit in either study. (ClinicalTrials.gov numbers, NCT00004978 [ESPRIT] and NCT00013611 [SILCAAT study].)

Effect of early initiation of highly active antiretroviral therapy on CD4 cell count and HIV-RNA viral load trends within 24 months of the onset of acute retroviral syndrome

OBJECTIVES

The effect of starting highly active antiretroviral therapy (HAART) early after the onset of acute retroviral syndrome (ARS) on CD4 and HIV-RNA trends was studied over a 2-year follow-up period.

METHODS

Four groups of HIV-infected patients stratified according to the time interval from ARS onset to HAART initiation and a control group of untreated patients were compared.

RESULTS

The results indicated that the earlier the start of HAART, the faster was the rate of CD4 increase and HIV-RNA decrease. However, this difference did not seem to persist at 24 months.

CONCLUSIONS

The optimal treatment strategy for HIV-infected patients needs to be explored further.

Early changes in adipokine levels and baseline limb fat may predict HIV lipoatrophy over 2 years following initiation of antiretroviral therapy

BACKGROUND

No biological marker has been identified that predicts the development of lipodystrophy (LD). We investigated whether metabolic and body composition parameters could predict the development of LD over 2 years in adults initiating antiretroviral therapy (ART).

METHODS

We used stored plasma collected at baseline and weeks 12, 24 and 48 from adults initiating combination ART. Adipocytokine, inflammatory cytokine, lipid and glycaemic parameters were measured and related to subsequent lipoatrophy (loss of limb fat mass of at least 2 kg from weeks 24 to 96 by dual-energy X-ray absorptiometry) and an increase in visceral adipose tissue (VAT; an increase of at least 18 cm(2) from baseline to week 48 by abdominal computed tomography). Risk factors associated with limb fat loss and VAT gain were analysed by logistic regression.

RESULTS

Fifty-four HIV-infected, treatment-naïve adults were included in the study: 53 (98%) of them were men, and they had a median age of 39 years [interquartile range (IQR) 34-48 years] and a median body mass index of 22.6 kg/m(2) (IQR 20-24.8 kg/m(2)). In multivariate analysis, a higher baseline limb fat percentage, and a 1 mmol/L increase in plasma leptin levels during the first 6 months of ART, independently predicted a peripheral fat loss of > or = 2 kg [odds ratio (OR) 2.58, 95% confidence interval (CI) 1.04-6.41; OR 3.15, 95% CI 1.34-7.35, respectively). VAT changes showed a borderline association with high baseline tumour necrosis factor-alpha levels and hip circumference (OR 1.04, 95% CI 1.00-1.07; OR 1.44, 95% CI 1.07-1.95, respectively).

CONCLUSIONS

In ART-naïve men, higher baseline limb fat and an early increase in leptin concentrations may predict the subsequent development of lipoatrophy. We did not find the same risk factors in the two different groups of patients with peripheral fat loss and central fat gain, suggesting a partially independent pathogenesis.

The public health impact of widespread availability of nonoccupational postexposure prophylaxis against HIV

OBJECTIVE

The aim of the study was to describe the use of nonoccupational postexposure prophylaxis (NPEP) in Australia, and to estimate the number of HIV infections that its use prevented.

METHODS

We conducted a population-based observational cohort study of people who presented to antiretroviral prescribers in Eastern Australia, and reported a high-risk nonoccupational exposure to HIV, in 1998-2004. Prescribers collected data at baseline, 4 weeks and 6 months. Data collected included details of HIV exposure, drug regimens and HIV serostatus.

RESULTS

The great majority of the 1601 participants were male (95%) and presented after male homosexual exposure (87%). Only 32% of exposures were to HIV-positive sources. Two antiretroviral drugs were prescribed after 48% of events, and three or more drugs after 52% of events. The median time to receipt of NPEP was 23 h. Side effects were reported by 66% of participants. No case of NPEP failure in an adherent individual was identified. It was estimated that 0.9-9.2 HIV infections had been prevented. This compared with a total of 1138 newly acquired HIV infections notified in the geographical area covered by the study.

CONCLUSIONS

In Australia, NPEP has been widely prescribed and is mainly targeted at high-risk exposures. Although there were no identified failures of NPEP, it is likely that only a small proportion of new HIV infections in the study area were prevented. NPEP may be a valuable preventive intervention for an individual, but it can only play a minor role in HIV prevention at the population level unless targeting can be further improved.

Predictive factors for immunological and virological endpoints in Thai patients receiving combination antiretroviral treatment

BACKGROUND

Routine CD4 count and HIV viral load monitoring is a financial barrier in developing countries.

METHODS

We assessed factors associated with CD4 counts < or =200 cells/microL and detectable viral load in Thai HIV-infected patients receiving antiretroviral therapy (ART) at the HIV Netherlands Australia Thailand Research Collaboration and the Thai Red Cross AIDS Research Centre (HIV-NAT). Univariate and multivariate Cox proportional hazards models for multiple treatment failures were used to determine factors related to CD4 counts < or =200 cells/microL and detectable viral load. Multivariate Cox proportional hazards models for CD4 counts < or =200 cells/microL were developed with and without viral load in order to build models applicable to contexts in which viral load is not available.

RESULTS

Four hundred and seventeen patients were included in the study. Fifty-four per cent were male, and the median CD4 count and log(10) viral load at baseline were 283 cells/microL and 4.3 log(10) HIV-1 RNA copies/mL, respectively. Independent factors related to CD4 count < or =200 cells/microL were CD4 count at baseline [hazards ratio (HR) 0.20/100 cells/microL; 95% confidence interval (CI) 0.17-0.23] and changes in CD4 count (HR 0.22/100 cells/microL; 95% CI 0.17-0.28). Factors in multivariate models (in which viral load was considered for inclusion) were CD4 count at baseline (HR 0.21/100 cells/microL; 95% CI 0.18-0.24), changes in CD4 count (HR 0.25/100 cells/microL; 95% CI 0.19-0.32) and detectable viral load (HR 1.94; 95% CI 1.20-3.13). Predictive factors (independent of viral load) were triple ART or highly active antiretroviral therapy (HAART) (HR 0.28; 95% CI 0.22-0.36) and detectable viral load at baseline (HR 2.96; 95% CI 2.24-3.91). Conclusions CD4 count at baseline and changes in CD4 count were important in predicting CD4 counts < or =200 cells/microL. Triple ART and detectable viral load at baseline were important in predicting detectable viral load.

Experience with the use of a first-line regimen of stavudine, lamivudine and nevirapine in patients in the TREAT Asia HIV Observational Database

BACKGROUND

The antiretroviral treatment (ART) combination of stavudine, lamivudine and nevirapine (d4T/3TC/NVP) is the most frequently used initial regimen in many Asian countries. There are few data on the outcome of this treatment in clinic cohorts in this region.

METHODS

We selected patients from the TREAT Asia HIV Observational Database (TAHOD) who started their first ART regimen with d4T/3TC/NVP. Treatment change was defined as cessation of therapy or the addition or change of one or more drugs. Clinical failure was defined as diagnosis with an AIDS-defining illness, or death while on d4T/3TC/NVP treatment.

RESULTS

The rate of treatment change among TAHOD patients starting d4T/3TC/NVP as their first antiretroviral treatment was 22.3 per 100 person-years, with lower baseline haemoglobin (i.e. anaemia) associated with slower rate of treatment change. The rate of clinical failure while on d4T/3TC/NVP treatment was 7.3 per 100 person-years, with baseline CD4 cell count significantly associated with clinical failure. After d4T/3TC/NVP was stopped, nearly 40% of patients did not restart any treatment and, of those who changed to other treatment, the majority changed to zidovudine (ZDV)/3TC/NVP and less than 3% of patients changed to a protease inhibitor (PI)-containing regimen. The rates of disease progression on the second-line regimen were similar to those on the first-line regimen.

CONCLUSION

These real-life data provide an insight into clinical practice in Asia and the Pacific region. d4T/3TC/NVP is maintained longer than other first-line regimens and change is mainly as a result of adverse effects rather than clinical failure. There is a need to develop affordable second-line antiretroviral treatment options for patients with HIV infection in developing countries.

Ovarian, hormonal, and reproductive events associated with synchronization of ovulation and timed appointment breeding of Bos indicus-influenced cattle using intravaginal progesterone, gonadotropin-releasing hormone, and prostaglandin F2α1

The objectives of this study were to 1) compare cumulative pregnancy rates in a traditional management (TM) scheme with those using a synchronization of ovulation protocol (CO-Synch + CIDR) for timed AI (TAI) in Bos indicus-influenced cattle; 2) evaluate ovarian and hormonal events associated with CO-Synch + CIDR and CO-Synch without CIDR; and 3) determine estrual and ovulatory distributions in cattle synchronized with Select-Synch + CIDR. The CO-Synch + CIDR regimen included insertion of a controlled internal drug-releasing device (CIDR) and an injection of GnRH (GnRH-1) on d 0, removal of the CIDR and injection of PGF2alpha (PGF) on d 7, and injection of GnRH (GnRH-2) and TAI 48 h later. For Exp. 1, predominantly Brahman x Hereford (F1) and Brangus females (n = 335) were stratified by BCS, parity, and day postpartum (parous females) before random assignment to CO-Synch + CIDR or TM. To maximize the number of observations related to TAI conception rate (n = 266), an additional 96 females in which TM controls were not available for comparison also received CO-Synch + CIDR. Conception rates to TAI averaged 39 +/- 3% and were not affected by location, year, parity, AI sire, or AI technician. Cumulative pregnancy rates were greater (P < 0.05) at 30 and 60 d of the breeding season in CO-Synch + CIDR (74.1 and 95.9%) compared with TM (61.8 and 89.7%). In Exp. 2, postpartum Brahman x Hereford (F1) cows (n = 100) were stratified as in Exp. 1 and divided into 4 replicates of 25. Within each replicate, approximately one-half (12 to 13) received CO-Synch + CIDR, and the other half received CO-Synch only (no CIDR). No differences were observed between treatments, and the data were pooled. Percentages of cows ovulating to GnRH-1, developing a synchronized follicular wave, exhibiting luteal regression to PGF, and ovulating to GnRH-2 were 40 +/- 5, 60 +/- 5, 93 +/- 2, and 72 +/- 4%, respectively. In Exp. 3, primiparous Brahman x Hereford, (F1) heifers (n = 32) and pluriparous cows (n = 18) received the Select Synch + CIDR synchronization regimen (no GnRH-2 or TAI). Mean intervals from CIDR removal to estrus and ovulation, and from estrus to ovulation were 70 +/- 2.9, 99 +/- 2.8, and 29 +/- 2.2 h, respectively. These results indicate that the relatively low TAI conception rate observed with CO-Synch + CIDR in these studies was attributable primarily to failure of 40% of the cattle to develop a synchronized follicular wave after GnRH-1 and also to inappropriate timing of TAI/GnRH-2.

Virological and immunological outcomes at 3 years after starting antiretroviral therapy with regimens containing non-nucleoside reverse transcriptase inhibitor, protease inhibitor, or both in INITIO: open-label randomised trial

BACKGROUND

Antiretroviral therapy has greatly reduced HIV mortality and morbidity. However, the best sequence of regimens and implications of initial regimen for long-term therapeutic success are not well defined.

METHODS

In INITIO, a large international randomised trial, we compared antiretroviral therapy with two nucleoside analogue reverse transcriptase inhibitors (didanosine+stavudine) plus either a non-nucleoside reverse transcriptase inhibitor (efavirenz, EFV) or a protease inhibitor (nelfinavir, NFV), or both (EFV/NFV), in patients with HIV-1 infection who had not previously received antiretroviral drugs. Primary outcomes were proportion with undetectable HIV RNA in plasma, and change in CD4 count from baseline at 3 years. Analyses were by intention-to-treat. This study is registered as an International Standard Randomised Controlled Trial, number ISRCTN44582462.

FINDINGS

We followed up 911 participants (297 EFV, 311 NFV, 303 EFV/NFV). At 3 years, the proportion with HIV RNA less than 50 copies per mL was highest in the EFV group (188 [74%] EFV, 162 [62%] NFV, 155 [62%] EFV/NFV; p=0.004). Mean (95% CI) increases in CD4 count were 316x10(6) cells per L (288-343) for EFV, 289x10(6) cells per L (262-316) for NFV, and 274x10(6) cells per L (231-291) for EFV/NFV (p=0.1). Fewer participants in the EFV group than in the other groups stopped adequate antiretroviral therapy for more than 30 days (p=0.005). Participants in the EFV/NFV group had shorter time to stopping the initial regimen (p<0.0001) and to a treatment modifying adverse event (p=0.04) than those in the other groups.

INTERPRETATION

Starting antiretroviral therapy with a three-drug/two-class regimen including efavirenz was better than starting with regimens including nelfinavir or efavirenz plus nelfinavir in terms of virological suppression and durability of the initial regimen. The shorter time on adequate antiretroviral therapy or to a treatment-modifying adverse event might explain the absence of additional benefit for the four-drug regimen.

Is screening for sexually transmitted infections in men who have sex with men who receive non-occupational HIV post-exposure prophylaxis worthwhile?

BACKGROUND/AIMS

Non-occupational HIV post-exposure prophylaxis (NPEP) is routinely prescribed after high risk sexual exposure. This provides an opportunity to screen and treat individuals at risk of concurrent sexually transmitted infections (STI). The aim of this study was to assess the efficacy of an STI screening programme in individuals receiving NPEP.

METHODS

STI screens were offered to all individuals receiving NPEP from March 2001 to May 2004. Screen results were compared to type of sexual exposure and baseline patient characteristics.

RESULTS

A total of 253 subjects were screened, representing 85% of the target population. All were men who have sex with men (MSM). Common exposure risks were receptive anal intercourse (RAI) in 61% and insertive anal intercourse (IAI) in 33%. 32 (13%) individuals had one or more STI. The most common STIs were rectal infections with Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) in 11 (4.5%) and six (2.5%) individuals, respectively. Subjects with rectal CT were significantly more likely to be co-infected with rectal NG (p<0.001). There was no association between the presence of a rectal STI and age or exposure risk. Only six (19%) individuals with an STI were symptomatic at screening.

CONCLUSION

In this cohort of MSM receiving NPEP, high rates of concomitant STIs are observed highlighting the importance of STI screening in this setting.

Minor changes in calculated creatinine clearance and anion-gap are associated with tenofovir disoproxil fumarate-containing highly active antiretroviral therapy

BACKGROUND

Tenofovir disoproxil fumarate (Tenofovir DF, TDF), the first nucleotide reverse transcriptase inhibitor approved for the treatment of HIV disease, has been associated with renal dysfunction in isolated cases. The aim of this study was to assess changes in renal parameters in individuals receiving TDF- and non-TDF-containing highly active antiretroviral therapy (HAART).

METHODS

All individuals on HAART attending our clinic were included in the analysis. Time-weighted changes in serum creatinine, calculated creatinine clearance (CCrCl) and anion-gap were assessed for individuals on TDF- and non-TDF HAART.

RESULTS

Of 948 individuals on HAART, 290 (31%) and 618 (65%) were on TDF- and non-TDF HAART, with 40 (4%) having ceased TDF HAART. Baseline values for serum creatinine, CCrCl and anion-gap were similar for those on TDF- and non-TDF HAART. In a multivariate analysis, statistically significant differences were observed in time-weighted change from baseline in anion-gap and CCrCl between individuals on TDF- and non-TDF HAART [mean difference in change between groups: anion-gap 0.78 mmol/L (standard error, 0.19) and CCrCl-6.80 (standard error 2.2); P = 0.005 and P = 0.032, respectively] after adjusting for baseline anion-gap and CCrCl, respectively. Two cases of TDF-associated renal failure were observed.

CONCLUSION

Overt renal failure with TDF HAART is rare. However, subtle but statistically significant changes in anion-gap and CCrCl were observed which were associated with TDF HAART. These parameters may be of use in monitoring individuals on HAART.

Randomized, placebo-controlled, phase I/IIa evaluation of the safety and immunogenicity of fowlpox virus expressing HIV gag-pol and interferon-gamma in HIV-1 infected subjects

We conducted a randomized, placebo-controlled double-blind trial to examine the safety and immunogenicity of a candidate HIV therapeutic vaccine based upon a recombinant fowl pox virus capable of coexpressing the human cytokine interferon-gamma and/or genes from HIV-1. Thirty-five eligible subjects were randomized (12 placebo, 11 fowlpox + HIV genes, 12 fowl pox + HIV genes + interferon gamma). All but one subject (placebo group) received three immunizations (by intramuscular injection on day 0, week 4 and week 12) and all completed 52 weeks of follow-up. All subjects continued to take combination antiretroviral therapy for the duration of study. There were no significant toxicity or safety concerns and the distribution of adverse events and their severity was consistent across each randomly assigned vaccine group. Comparison of placebo recipients with the combined recipients of the two vaccine constructs, in terms of anti-HIV gag ELISpot or lymphoproliferative responses, tended to favour the placebo group, but were not significantly different (difference in time-weighted mean change from baseline = 56 Spot forming units (sfu)/10(6) PBMC; p = 0.062 and 4.4 SI; p = 0.337). There were no significant changes in CTL responses by standard Cr(51) release assay. Anti-FPV antibodies were detected by week 14 in 0 placebo and 20 (87%) vaccine recipients. Although safe, neither vaccine construct appeared to possess detectable T-cell mediated anti-HIV immunogenic properties in HIV infected individuals, as measured by standard T cell assays.

Indinavir/ritonavir 800/100 mg bid and efavirenz 600 mg qd in patients failing treatment with combination nucleoside reverse transcriptase inhibitors: 96-week outcomes of HIV-NAT 009

OBJECTIVE

Nucleoside reverse transcriptase (NRTI) sparing is a favourable option for patients with NRTI failure or toxicity.

METHODS

Patients judged to be failing NRTI therapy were enrolled in a single-arm, open-label study of indinavir/ritonavir (IDV/r) 800/100 mg twice a day (bid)+efavirenz (EFV) 600 mg once a day (qd). The primary endpoint was the change in time-weighted average HIV RNA from baseline. The initial 48-week protocol was extended to 96 weeks by a single amendment. Analysis was by intention to treat.

RESULTS

Sixty-one patients (23 female) were enrolled in the study. Baseline median inter-quartile range (IQR) NRTI exposure was 4.4 (3.9-4.7) years; baseline median viral load was 4.09 log(10) HIV-1 RNA copies/mL (range 3.75-4.61 log(10) copies/mL); baseline median CD4 count was 169 cells/microL (range 60-277 cells/microL). The mean (SD) change in time-weighted average HIV RNA from baseline at 48 and 96 weeks was -2.1 (0.7) and -2.1 (0.8) log(10) copies/mL respectively, resulting in 87% and 69% of patients with HIV RNA <50 copies/mL. Sixteen per cent of patients permanently ceased therapy and 26% underwent temporary drug interruptions because of study drug-related adverse events. Fasted-lipid values rose significantly over the 96 weeks of study, as did median blood glucose and median serum creatinine levels. Twelve (20%) patients underwent IDV dose reduction, mainly because of nephrotoxicity (nine of 12 patients). Blood pressure values deteriorated following switch, but markers of nucleoside toxicity improved.

CONCLUSIONS

IDV/r 800/100 mg bid+EFV 600 mg qd gave a potent, durable response in these NRTI failures and was reasonably well tolerated. However, we observed adverse effects on renal, metabolic and blood pressure parameters. Lower doses of boosted IDV might improve toxicity while maintaining efficacy, and this possibility warrants further investigation.

The use of a triple nucleoside-nucleotide regimen for nonoccupational HIV post-exposure prophylaxis

OBJECTIVES

Nonoccupational post-exposure prophylaxis (NPEP) for HIV is recommended after high-risk sexual exposure. Because of the high incidence of intolerable side effects observed with protease inhibitor- and zidovudine-based NPEP regimens, our unit changed standard NPEP treatment to 28 days of tenofovir-lamivudine-stavudine (TDF-3TC-d4T). The aim of this study was to compare side effects and numbers of individuals completing NPEP before and after this change.

METHODS

Parameters were compared amongst individuals commencing the following NPEP regimens: zidovudine-lamivudine (ZDV-3TC), zidovudine-lamivudine-nelfinavir (ZDV-3TC-NFV) and TDF-3TC-d4T.

RESULTS

A total of 385 individuals received ZDV-3TC (n = 36), ZDV-3TC-NFV (n = 225) or TDF-3TC-d4T (n = 137) as NPEP for the first time between June 1999 and November 2003. Noncompletion rates were 25%, 32% and 15%, respectively (P = 0.001), with odds ratios for noncompletion being 2.0 [95% confidence interval (CI) 0.8-4.8] and 2.7 (95% CI 1.6-4.8) in the first two groups compared with the TDF-3TC-d4T group (P = 0.008). Adverse events were less common in the TDF-3TC-d4T group, with significantly lower rates of nausea and headache, but significantly higher rates of peripheral neuropathy and asymptomatic raised transaminases. There was no HIV seroconversion in any group.

CONCLUSIONS

TDF-3TC-d4T is significantly better tolerated than ZDV-3TC or ZDV-3TC-NFV as NPEP and results in greater numbers of individuals completing 28 days of treatment.

HIV and hepatitis C coinfection within the CAESAR study

The declining incidence of AIDS-related opportunistic diseases among people with HIV infection has shifted the focus of clinical management to prevention and treatment of comorbidities such as chronic liver disease. The increased risk of hepatitis C virus (HCV)-related advanced liver disease in people with HIV infection makes early HCV diagnosis a priority. To assess HCV prevalence and predictors of HIV/HCV coinfection, we have conducted a retrospective analysis of people enrolled in the CAESAR (Canada, Australia, Europe, South Africa) study, a multinational randomized placebo-controlled study of the addition of lamivudine to background antiretroviral therapy. The impact of HCV on HIV disease progression was also examined. Anti-HCV antibody testing on 1649 CAESAR study participants demonstrated a HIV/HCV coinfection prevalence of 16.1%, which varied from 1.9% in South Africa to 48.6% in Italy. The strongest predictor of HIV/HCV coinfection was HIV exposure category (P<0.0001), with odds ratios (ORs) compared to homosexual as follows: injecting drug use (IDU), 365 [95% confidence interval (CI): 179-742]; transfusion or blood products, 32.2 (95% CI: 15.2-67.6); homosexual and IDU, 22.9 (95% CI: 8.5-62.1). The prevalence of HIV/HCV was low (3.7%) among homosexual men without reported IDU. Other predictors of HIV/HCV coinfection were alanine aminotransferase (ALT), country of residence, ethnicity and stage of HIV disease. A history of IDU or ALT > or =40 U/L at baseline had a positive predictive value (PPV) of 35%, negative predictive value (NPV) of 96%, sensitivity of 82% and specificity of 71% for HIV/HCV coinfection. HIV disease progression was similar in HIV monoinfected and HIV/HCV coinfected patients. People with HIV and a history of IDU or elevated liver function tests should be targeted for HCV testing. The low prevalence of HIV/HCV coinfection among homosexual men without a history of IDU suggests low efficiency of sexual HCV transmission.

HIV Lipodystrophy Case Definition using Artificial Neural Network Modelling

Objective

A case definition of HIV lipodystrophy has recently been developed from a combination of clinical, metabolic and imaging/body composition variables using logistic regression methods. We aimed to evaluate whether artificial neural networks could improve the diagnostic accuracy.

Methods

The database of the case-control Lipodystrophy Case Definition Study was split into 504 subjects (265 with and 239 without lipodystrophy) used for training and 284 independent subjects (152 with and 132 without lipodystrophy) used for validation. Back-propagation neural networks with one or two middle layers were trained and validated. Results were compared against logistic regression models using the same information.

Results

Neural networks using clinical variables only (41 items) achieved consistently superior performance than logistic regression in terms of specificity, overall accuracy and area under the ROC curve. Their average sensitivity and specificity were 72.4 and 71.2%, as compared with 73.0 and 62.9% for logistic regression, respectively (area under the ROC curve, 0.784 vs 0.748). The discriminating performance of the neural networks was largely unaffected when built excluding 13 parameters that patients may not have readily available. The average sensitivity and specificity of the neural networks remained the same when metabolic variables were also considered (total 60 items) without a clear advantage against logistic regression (overall accuracy 71.8%). The performance of networks considering also body composition variables was similar to that of logistic regression (overall accuracy 78.5% for both).

Conclusions

Neural networks may offer a means to improve the discriminating performance for HIV lipodystrophy, when only clinical data are available and a rapid approximate diagnostic decision is needed. In this context, information on metabolic parameters is apparently not helpful in improving the diagnosis of HIV lipodystrophy, unless imaging and body composition studies are also obtained.

Combined analysis of two-year follow-up from two open-label randomized trials comparing efficacy of three nucleoside reverse transcriptase inhibitor backbones for previously untreated HIV-1 infection: OzCombo 1 and 2

PURPOSE

To compare inhibition of HIV replication, improvements in CD4+ T-cell counts, metabolic parameters, and body shape changes after 2 years of assigned therapy in OzCombo patients.

METHOD

Study participants were those who were recruited into the open-label OzCombo 1 (1996/1997) and OzCombo 2 (1997/1998) trials. Patients in OzCombo 1 were randomized to receive indinavir in combination with zidovudine+lamivudine (AZT+3TC; n = 35), stavudine (d4T)+3TC (n = 34), or d4T+didanosine (ddI) (n = 37). OzCombo 2 patients were randomized to the same nucleoside reverse transcriptase inhibitor (NRTI) backbones with nevirapine (n = 20, 22, 23, respectively). The mean time-weighted changes from baseline in CD4 T-cell count/mL, HIV RNA (log copies/mL plasma), and proportions with detectable viral load (<500 copies plasma HIV RNA/mL) between NRTI arms over 2 years were compared by formal meta-analysis. A cross-sectional study of metabolic and body shape complications was also undertaken.

RESULTS

For the comparison of d4T+3TC and d4T+ddI to AZT+3TC, mean differences in time-weighted change from baseline in CD4 T-cell count/microL and log copies HIV RNA/mL adjusted for baseline CD4+ T-cell and HIV RNA counts were: -44 (p =.08) and -14 (p =.56) cells/microL and -0.1 (p =.40) and -0.1 (p =.6) copies/mL. Odds ratios for detectable viral load in the last study quarter were 0.6 (p =.44) and 1.0 (p =.95). The mean percent leg fat was lower in the d4T+3TC and d4T+ddI than the AZT+3TC arm (mean difference 5.1% [p =.07] and 7.6% [p =.02], respectively).

CONCLUSION

For all regimens, virological control and immunological response were maintained over 2 years. Regimens containing d4T and particularly d4T+ddI were significantly associated with increased peripheral fat loss compared with AZT+3TC.

HIV lipodystrophy: prevalence, severity and correlates of risk in Australia

OBJECTIVE

To establish the prevalence, severity and factors associated with the HIV lipodystrophy syndrome.

METHODS

Cross-sectional study of lipodystrophy conducted in high HIV caseload primary care sites and HIV outpatient clinics. A subset of patients was examined using dual energy X-ray absorptiometry (DEXA) and single cut abdominal computerized tomography (CT) at the L4 vertebral level to quantify regional and total body fat. Factors associated with lipodystrophy, lipoatrophy and lipohypertrophy were assessed using multiple logistic regression based on assignment of cases and non-cases.

RESULTS

One thousand, three hundred and forty-eight patients (95% male) were surveyed, 20% had AIDS, the mean CD4 lymphocyte count was 486 cells/microL, and 55% had <500 HIV-1 RNA copies/mL. Most participants (87%) had previously received or were currently receiving combination antiretroviral therapy, 73% with at least one protease inhibitor (PI) and 14% a non-PI-containing regimen. Lipodystrophy prevalence was 53% and of these, 55% reported both peripheral lipoatrophy and central lipohypertrophy, 31% experienced peripheral lipoatrophy only and 14% had central lipohypertrophy only. The prevalence of any body habitus change was 62% in PI-experienced patients, 33% in PI-naive patients and 21% in antiretroviral-naive patients. Lipodystrophy severity was less in antiretroviral-naive patients and most severe in PI-experienced patients. Increasing severity of lipodystrophy was both positively and significantly correlated with elevated liver enzymes, decreased testosterone levels, decreased skin-fold thickness, lower levels of total and peripheral fat (DEXA) and higher levels of visceral fat (CT). Lipodystrophy was also significantly associated with increasing age, symptomatic HIV disease, effective viral suppression, and increasing duration of therapy with both nucleoside reverse transcriptase inhibitors and PIs.

CONCLUSIONS

The prevalence and severity of lipodystrophy reflects both length and type of treatment with antiretroviral therapy and is associated with decreased testosterone, increases in liver enzymes and greater suppression of HIV RNA. The reports of lipodystrophy in a small percentage of antiretroviral-naive patients suggests that factors other than antiretroviral therapy may be involved in the aetiology of this syndrome or that some conditions, such as wasting or age-associated obesity, may mimic lipoatrophy and lipohypertrophy, respectively.

Heterozygosity for CCR5-Delta32 but not CCR2b-64I protects against certain intracellular pathogens

OBJECTIVE

To determine the association between CCR5 and CCR2b genotype and the clinical manifestation of first and subsequent AIDS-defining illnesses (ADIs).

METHODS

The distribution of ADIs was examined by CCR5 and CCR2b genotype in a subset of homosexual men enrolled in the Sydney AIDS Prospective Study. The expected number of ADIs was calculated from rates observed in the same tertiary hospital over the same period.

RESULTS

Information on initial ADI was collected for 117 homosexual men diagnosed with AIDS before January 1998. Of these individuals, 17 were heterozygous for the CCR5-Delta32 mutation and 11 were heterozygous for CCR2b-64I. The number of observed cases of Pneumocystis carinii pneumonia (PCP), toxoplasmosis, Mycobacterium avium complex (MAC) and cryptosporidiosis reported as a first ADI was substantially fewer in people heterozygous for the CCR5-Delta32 mutation than for those without the mutation, despite similar age, CD4 T-cell count at AIDS diagnosis, year of AIDS diagnosis and receipt of antiretroviral treatment. In addition, among individuals heterozygous for CCR5-Delta32 there were fewer cases of PCP, toxoplasmosis, MAC, and cryptosporidiosis observed as subsequent ADIs compared to the number expected, based on rates measured in the same hospital during the same period (seven observed vs. 24 expected, RR = 0.3, 95% CI = 0.01-0.6). The distribution of first and subsequent ADIs did not differ from the number expected in individuals heterozygous for the CCR2b-64I mutation.

CONCLUSION

Results from this study show that heterozygosity for CCR5-Delta32 but not CCR2b-64I appears to protect against opportunistic infections.

A role for olestra in body weight management

Olestra is a fat substitute made from fatty acids esterified to sucrose and can be used in the preparation of virtually any food made with fat. Foods made with olestra retain the mouthfeel, palatability and satiating effects of their full-fat counterparts without providing any digestible energy. Because olestra provides no energy, it has the potential to be a useful tool in weight loss and weight maintenance. Short-term studies of olestra replacement in foods demonstrate that fat replacement leads to a net reduction in fat intake. When excess total energy is available, fat replacement also reduces total energy intake in lean and obese men and women. In longer-term studies in which olestra is incorporated into the daily diet, there is an incomplete compensation for the fat energy replaced by olestra. When overweight men consumed olestra as part of a varied diet over nine months, weight loss continued for the duration of the study, whereas individuals receiving a typical low-fat diet regained most of the initial weight lost. Other studies are underway to examine the usefulness of olestra in long-term weight maintenance following weight loss. Post-marketing surveillance of olestra foods in the United States indicates that substitution of olestra for only 1-2 g of fat d-1 may be sufficient to prevent the average weight gain reported in adults of 0.5-1.0 kg year-1.

Characterization of the phenotypic and lymphokine profile associated with strong CD8+ anti-HIV-1 suppressor activity (CASA)

A panel of 22 CD8+ T cell lines, with a broad range of CD8+ anti-HIV-1 suppressor activity (CASA) were generated from a single patient with HIV-1 infection. CD8+ T cell lines with either strong or weak CASA were examined and compared for cell surface and intracellular markers, constitutive chemokine and lymphokine mRNA levels and inducible lymphokine expression. Strong CASA significantly correlated with CD8+ T cell lines that highly coexpressed the molecule CD28+ (r=0.52, P=0.01) and Ki67+ (r=0.88, P=0.02), with strong CASA CD8+ T cell lines demonstrating significantly higher (P < 0.05) expression of CD8+CD28+ and CD8+Ki67+ compared to those with weak activity. No such correlations or findings were observed for the markers CD38, HLA-DR, CD57 or perforin. The Th1 cytokines were expressed at greater levels than the Th2 cytokines, with strong CASA significantly associated with an increased inducible level of IL-2 production (P=0.05). Constitutive RANTES, IP-10 and I-309 mRNA expression were significantly (P < 0.05) elevated in CD8+ T cell lines exhibiting strong CASA compared to those with weak CASA. There was no significant difference in the mRNA expression of the lymphokines IL-2, 4, 5, 8, 9, 10, 14, 15, or chemokines MIP-1alpha, MIP-1beta, MCP-1, and Ltn. Strong CASA was therefore associated with rapidly replicating CD8+ T cells of the phenotype CD8+CD28+Ki67+ that expressed greater levels of IL-2 and the ligands RANTES and I-309.

The impact of HIV therapy on co-infection with hepatitis B and hepatitis C viruses

Improving survival for people with HIV has brought management of co-morbidities into focus. In the era of highly active antiretroviral therapy, co-infection with either hepatitis B virus and/or hepatitis C virus, and HIV therapies themselves, have increased liver disease-related morbidity and mortality. The dual anti-HIV and anti-hepatitis B activity of several established and emerging therapeutic agents provides the opportunity to both restore immune function and prevent liver disease progression in people with HIV-hepatitis B virus co-infection. Improving hepatitis C antiviral therapy also provides optimism around management of liver disease in people with HIV-hepatitis C virus co-infection. However, formulation of appropriate therapeutic strategies for HIV-hepatitis B and HIV-hepatitis C co-infection requires further research, including clinical trials of combination antiviral therapy with specific anti-hepatitis B and anti-hepatitis C activity. A possible role may also exist for combined antiviral and immune-based therapies.

Relation between dietary intake, serum concentrations, and retinal concentrations of lutein and zeaxanthin in adults in a Midwest population

BACKGROUND

Information on concentrations of retinal carotenoids (macular pigment, or MP) is of particular interest because MP protects against age-related macular degeneration, the leading cause of irreversible blindness in the United States.

OBJECTIVE

This study was designed to evaluate the relation between dietary intake, blood concentrations, and retinal concentrations of carotenoids in a large group of volunteers.

DESIGN

Two hundred eighty volunteers in the Indianapolis area completed health and diet questionnaires, donated a blood sample, and participated in MP density assessment to determine retinal carotenoid status. Dietary intake was assessed by food-frequency questionnaire. Serum concentrations of lutein, zeaxanthin, and beta-carotene were measured by HPLC. MP optical density (MPOD) was determined psychophysically with a 460-nm, 1 degrees test stimulus.

RESULTS

Average MPOD was 0.21 +/- 0.13. Average intakes of lutein + zeaxanthin and beta-carotene were 1101 +/- 838 and 2935 +/- 2698 microg/d, respectively. Although several key dietary intake variables (eg, lutein + zeaxanthin and beta-carotene) differed by sex, no significant sex differences were found in either serum concentrations of lutein and zeaxanthin or MPOD. Serum beta-carotene concentrations were significantly higher in women than in men. Serum lutein + zeaxanthin and dietary intake of lutein + zeaxanthin were significantly correlated and significantly related to variations in MPOD (r = 0.21, P < 0.001, and r = 0.25, P < 0.001, respectively).

CONCLUSIONS

Retinal carotenoids can be measured in epidemiologic studies. In this study, MPOD was associated with lutein + zeaxanthin in the diet and the serum. Retinal concentrations, however, were influenced by other factors as well. To understand the effect of dietary lutein + zeaxanthin intake on the retina and risk of age-related eye disease, future studies should include measures of macular concentrations of these pigments.

HIV protease inhibitors protect apolipoprotein B from degradation by the proteasome: a potential mechanism for protease inhibitor-induced hyperlipidemia

Highly active anti-retroviral therapies, which incorporate HIV protease inhibitors, resolve many AIDS-defining illnesses. However, patients receiving protease inhibitors develop a marked lipodystrophy and hyperlipidemia. Using cultured human and rat hepatoma cells and primary hepatocytes from transgenic mice, we demonstrate that protease inhibitor treatment inhibits proteasomal degradation of nascent apolipoprotein B, the principal protein component of triglyceride and cholesterol-rich plasma lipoproteins. Unexpectedly, protease inhibitors also inhibited the secretion of apolipoprotein B. This was associated with inhibition of cholesteryl-ester synthesis and microsomal triglyceride transfer-protein activity. However, in the presence of oleic acid, which stimulates neutral-lipid biosynthesis, protease-inhibitor treatment increased secretion of apolipoprotein B-lipoproteins above controls. These findings suggest a molecular basis for protease-inhibitor-associated hyperlipidemia, a serious adverse effect of an otherwise efficacious treatment for HIV infection.