Current HIV Research - Volume 7, Issue 5, 2009

In June 2007, the European Medicines Agency announced the recall by Roche of nelfinavir from European Union markets because of contamination of tablets with ethyl mesylate. Based on this event, we investigated the effect of switching therapy because of nelfinavir recall or for other reasons on the perception of therapy benefits and adherence to treatment in HIV-infected children and their caregivers. Thirty-eight children (mean age 12.1±6.7 years) were enrolled. A 35-item questionnaire was administered to the caregivers of enrolled children. Adherence was evaluated through a 4-day recall adherence instrument. Enrolled children were divided into 3 groups: patients who were shifted because of nelfinavir recall (group A, 8 patients); patients who were shifted for other reasons (group B, 12 patients); patients who were not shifted in the last 6 months (group C, 18 patients). All caregivers considered antiretroviral therapy necessary and effective for their children. However, drug shifting generated anxiety in most of them, irrespective of the reason for shifting. At baseline, 74% patients adhered to therapy. Adherence rate was related to the type of caregivers being higher in children cared for by foster parents than in children cared for by biological parents or second-degree relatives. Adherence rates did not change significantly in groups A and B after switching. Drug-switching raises concern in caregivers of HIV-infected children and induces a negative feeling irrespective of the reason for switching. However, switching, including the shift due to nelfinavir recall, did not affect adherence rates.

Acute appendicitis as a manifestation of the immune reconstitution inflammatory syndrome is repeatedly discussed in the literature, but only a few cases of acute appendicitis associated with the initiation of cART have been published as yet. We describe a case of a young HIV-infected man who suffered from acute appendicitis early after the successful switch of a failing cART regimen.

Cerebrovascular disease (CVD) has early been recognized in HIV-infected patients, including infectious arteritis, inflammatory vasculitis, aneurismal and small-vessel arteriopathy, to which adds now the premature atherosclerotic cerebral arteriopathy associated with the highly active antiretroviral therapy (HAART)-induced metabolic disorders. As a result of the increased life-expectancy associated with HAART, HIV patients grow older and are exposed to the combined vascular risk of antiviral-induced metabolic changes and advancing age. Several studies have documented subclinical cervical artery atherosclerosis, as assessed by intima-media thickness, ultrasound detection of carotid artery plaques and intracerebral small-vessel disease, all being associated with the induced metabolic changes. This suggests that vascular prevention should be performed on a long-term basis.

The prevalence of diabetes in the United States is rising. As HIV-infected people live longer, they become more susceptible to chronic diseases such as diabetes. Additionally, some antiretroviral agents have been linked to impaired glucose tolerance and increased diabetes risk. To estimate the burden and trends of diabetes among hospitalized HIV-infected persons in the United States, we used data from the 1994-2004 Nationwide Inpatient Sample, a nationally representative survey of inpatient hospitalizations. Odds ratios (OR) and 95% confidence intervals (CI) were adjusted for demographic and hospital characteristics using logistic regression. Between 1994 and 2004, the rate of hospitalizations with a diabetes code per 100 hospitalizations increased from 3.9 to 8.4 (2.2 fold) among HIV-infected persons. Among HIV-uninfected people, the corresponding rate increased from 12.8 to 17.7 (1.4 fold). Since 1998, the mean age of HIVinfected hospitalized people with a diabetes diagnosis rose from 45 to 66 years and became similar to that of HIVuninfected people. Compared to 1994-1996, in 2002-2004 the probability of hospitalizations with diabetes increased among both HIV-infected and HIV-uninfected persons (OR, 1.92, 95% CI, 1.79-2.05 and OR, 1.38, 95% CI, 1.36-1.40, respectively). Given the increasing prevalence of diabetes in hospitalized HIV-infected persons, it will be important to monitor the trends closely in addition to the effects of different types of antiretroviral regimens, in order to optimize comprehensive long-term care of HIV-infected persons.

In the absence of effective treatment, infection with the human immunodeficiency virus (HIV) ultimately leads to the acquired immune deficiency syndrome (AIDS). Many attempts have been made to prevent and attenuate HIV infection. While antiretroviral therapies for infected individuals have had great success, preventative and therapeutic vaccines focused on both humoral and cell-mediated immunity have failed. Recently, several natural killer cell receptor (NKR) genotypes, in concert with certain class I human histompatibility-linked antigens (HLA) were found to be associated with protection from HIV infection and/or disease progression. These receptors are expressed on both natural killer (NK) cells and subsets of T lymphocytes. As HIV infection is often associated with attenuation of NK cells and much remains unknown about the basic functions of NKR, it remains undetermined whether the protective effect of these receptors relates to their expression on NK cells, T lymphocytes or both. This review summarizes current literature regarding NKR and HIV infection, and addresses several major questions remaining about the role of these receptors in protection against infection and disease progression.

A current debate in the HIV-1 vaccine field concerns the ability of an immunodeficiency virus to elicit a protective response. One argument is that HIV-1 superinfections are frequent in healthy individuals, because virus evades conventional immune surveillance, a serious obstacle to vaccine design. The opposing argument is that protection from superinfection is significant, reflecting a robust immune response that might be harnessed by vaccination to prevent disease. In an experiment designed to address the debate, two macaques received an I.V. inoculation with SHIV KU-1-d (a derivative of SHIV KU-1) and were rested for >10 months. Infection elicited diverse neutralizing antibody activities in both animals. Animals were then exposed to SHIV 89.6P (I.V.), a virus carrying a heterologous envelope protein relative to the vaccine strain. Infection was monitored by viral load and CD4+ T-cell measurements. All control animals were infected and most succumbed to disease. In contrast, protection from superinfection was statistically significant in test monkeys; one animal showed no evidence of superinfection at any time point and the second showed evidence of virus at only one time point over a 6-month observation period. Neither animal showed signs of disease. Perhaps this protective state may serve as a ‘gold-standard’ for HIV-1 vaccine development, as a similar degree of protection against immunodeficiency virus infections in humans would be much desired.

Chronic infection by herpes simplex virus type 2 (HSV-2) increases HIV susceptibility, perhaps due to HSV-2- associated increases in activated mucosal immune cells. A small number of Kenyan female sex workers (FSWs) exhibit relative HIV resistance. We examined whether relative HIV resistance was related to differences in the prevalence or mucosal immune impact of HSV-2. Participants were recruited from an open cohort of HIV-uninfected FSWs in Nairobi, Kenya. Women who had been practicing sex work in the cohort for ≥3 years without acquiring HIV were defined as relatively HIV resistant. HSV-2 diagnostics were performed, and cervical immune cell subsets were examined by flow cytometry in a subset of participants. The study population comprised 139 HIV-uninfected FSWs. HSV-2 seroprevalence was actually higher in FSWs meeting criteria for relative HIV resistance than in non-resistant FSWs (75/80, 94% vs 46/59, 78%; LR = 7.5; P = 0.006), likely due to the increased age and longer duration of sex work in the resistant subgroup. Late HIV acquisition was not associated with recent HSV-2 infection, and HSV-2 associated increases in HIVsusceptible cervical immune cell populations were similar in both groups. Relative HIV resistance in Kenyan FSWs was not due to a reduced prevalence or mucosal immune impact of HSV-2 infection.

HIV-1 exerts its most profound effects through destruction of the host's immune responses specifically through targeting of the T-lymphocyte populations. In addition to its primary immune target, HIV-1 also targets cells of the nervous, skeletal and vascular system. There is emerging evidence to suggest that HIV-1 may, in part at least, affect these diverse tissues by impairing the homeostatic production of terminally differentiated cells from stem and progenitor cell populations. The interaction between HIV-1 and stem cell populations may serve to underpin the diverse nonimmunological effects of HIV-1. This review deals with the effect of HIV-1 infection on a number of progenitor cell types, with emphasis on delineating mechanisms of HIV's destructive effect on the body. Modification of these effects may represent novel avenues for exploration in our search for clinical interventions.

The vpr gene of human immunodeficiency virus type 1 (HIV-1) plays an important role in the pathogenicity of viruses. Previous studies showed that mutation of certain sites in HIV-1 Vpr amino acid sequences might influence the clinical process of infected individuals and attenuate its apoptosis-inducing capacity on infected cells. The present study was designed to transfect hela cells with several HIV-1 vpr fragments carrying specific mutation sites, and to observe the distinction of apoptosis-inducing effects of different HIV-1 vpr variant fragments on host cells and explore the possible mechanisms. According to the previous results, 14 typical vpr variant fragments were chosen from Chinese HIV-1 infected individuals. After PCR amplification of vpr gene, the products were purified and double digested with Hind and BamHI. Then pcDNA3.1 (+) eukaryotic expression plasmids were used for the ligation and transduction experiments. The recombinant plasmids were transiently transfected into Hela cells with liposomes, and meanwhile the blank cell and empty vector cell were established as control. RT-PCR was used to detect the mRNA expression of target genes; fluorescent microscope for observing apoptotic cells with Hoechst staining; DNA agarose electrophoresis for detecting apoptotic gradient band; Annexin assay for detecting cell apoptosis; and Caspase activity test for exploring the pathway of cell apoptosis. After transfected with 14 vpr gene segments, the Hela cells exhibited various apoptosis-inducing capabilities. We found that the HIV-1 Vpr segments with mutation at the 70th, 85th, 86th, or 94th site showed lower apoptosis-inducing capabilities than other segments on Hela cells, and the apoptosis-inducing ability of HIV-1 vpr gene on host cells might be related to its subtype. Meanwhile, we found that the Caspase3 activity of transfected cell carrying these mutated fragment sites was decreased as compared to the cell with other fragments. This study firstly found that the HIV-1 Vpr fragments with the 70th, 85th, 86th, or 94th site mutation might attenuate their apoptosis-inducing abilities on Hela cells. One of the mechanisms might be the attenuation of Caspase-3 activity.

To report long-term data on safety and effectiveness of antiretroviral regimens, including nevirapine. HIV-1- infected patients who received nevirapine-based approaches for at least 4 years were identified in the databases of five centers and included in a retrospective cohort study. Data collected included plasma HIV-RNA (viral load) and CD4+ Tcell counts, lipid and liver function tests, at baseline, 2-year and > 4-year time points. Hepatitis C virus (HCV) coinfection, adverse events, and reasons for using nevirapine were also recorded. Two hundred and twenty-nine patients (139 males/90 females) were included. The mean age was 37 years (range 20-59). Most patients (n = 124; 54%) were former intravenous drug users. One hundred and thirty-five of the patients (59%) were coinfected with HCV. Median time on nevirapine was 72.6 months. The main reasons for nevirapine use included: second- or third-line therapy (39%), simplification of therapy (29%), first-line therapy (18%) and efavirenz intolerance (9%). LDL cholesterol and triglycerides decreased during the >4-year follow-up (135 mg/dl to 109 mg/dl, p = 0.04; and 216 mg/dl to 153 mg/dl, p<0.01, respectively), and HDL cholesterol increased from 48 mg/dl at baseline to 62 mg/dl (p<0.01). Liver enzymes remained without significant changes during follow-up. The reported follow-up pattern of laboratory tests was also found in the subset of HCV-coinfected patients, where men and women were compared and patients with a CD4+ cell count cutoff value of 250/mm3 were stratified. Mean CD4+ T-cell counts increased from 439/mm3 at baseline to 628/mm3 at the last available visit (p<0.001). Ninety-four per cent (172 out of 184) of patients who remained on nevirapine-based therapy at last visit maintained viral load values below the limit of detection (<50 copies/ml). Throughout the follow-up nevirapine was stopped or withdrawn in 43 patients due to virological failure (n = 17), toxicity (n = 5), therapy interruption (n = 3), death (n = 2), dyslipidemia (n = 1), simplification (n = 1) or unknown reasons (n = 14). Adverse events were reported in 40 patients but none was directly attributed to nevirapine. Nevirapine-based antiretroviral therapy provides sustained immunological and virological effectiveness over a more than 4-year treatment period as well as a beneficial lipid metabolic profile and a favorable safety profile, even in HCV-coinfected patients and women with CD4+ cell counts above 250/mm3. The study data support a nevirapine-based approach as a suitable long-term strategy in the HIV-1-infected population.

Peroxisome proliferator-activated receptor gamma (PPARγ) is involved in obesity and in some components of the metabolic syndrome in unselected population. To determine whether PPARγ genetic variants are associated with the risk of developing lipodystrophy and its associated metabolic disturbances in HIV-1-infected patients treated with HAART and to assess PPARγ mRNA expression in subcutaneous adipose tissue (SAT). The study group comprised 278 patients infected with HIV-1 and treated with antiretroviral drugs (139 with lipodystrophy and 139 without) and 105 uninfected controls (UC). The PPARγ Pro12Ala (C>G) single nucleotide polymorphism (SNP) was assessed using PCRRFLPs on white cell DNA. PPARγ mRNA expression in SAT was assessed in 38 patients (25 with lipodystrophy and 13 without) and in 21 UC by real-time PCR. Statistical analysis was based on Student's T tests, 2 tests, Spearman's correlations tests and logistic regression tests. PPARγ Pro12Ala genotype distribution and allele frequencies were nonsignificantly different between both HIV-1-infected categories, lipodystrophy vs non-lipodystrophy (p = 0.9 and p = 0.87, respectively). Lipodystrophic patients harbouring the rare X/Ala genotype (Ala/Ala plus Pro/Ala) had significantly greater plasma total and LDL cholesterol levels compared with carriers of the common Pro/Pro genotype (p = 0.029 and p = 0.016, respectively) at univariate analyses. At multivariate analyses these associations were no longer significant. There was a near-significant decreased SAT PPARγ mRNA expression in patients with lipodystrophy compared to UC (p = 0.054). PPARγ Pro12Ala SNP has no effect on the risk of developing lipodystrophy in HIV-1-infected patients treated with HAART. PPARγ mRNA SAT expression appears decreased in lipodystrophy.

Several reports have indicated that patients with low CD4+ cell count could be at a higher risk for arterial lesions or cardiovascular disease (CVD). Recently, current use of abacavir has been associated with an excess risk of CVD. High sensitivity-C-reactive protein and interleukin-6 levels were high for patients receiving the drug. These data lead to the hypothesis that alternative mechanisms may be at work other than those linked to lipid changes and “classic” risk factors for atheroma. Consequently, we investigated the ultrasound characteristics of carotid plaques in HIV-positive patients comparing the results with those obtained from patients affected by atherosclerosis and patients with arteritis. The study population included 110 HIV-positive patients and 91 HIV-negative patients (61 atherosclerotic patients and 30 with arteritis). All patients were subjected to ultrasonography of the epi-aortic vessels. When compared to atherosclerotic patients, there was a significantly higher proportion of HIV-positive patients with hypoechogenic and homogeneous lesions, uniform in their parietal and endoluminal portions with a smooth or slightly irregular surface. No significant differences were found between HIV-positive and arteritis patients. This ultrasonographic study confirms that inflammatory mechanisms could play a major role in the onset of vascular damage in HIV-1 positive patients.

In order to evaluate consistency and comparability of lipid reporting in antiretroviral treatment (ART) studies, 25 ART trials cited in the Department of Health and Human Services Guidelines were analyzed. Changes in lipids from a separate clinical cohort initiating ART were presented using different approaches to illustrate impact of various methods. Most trials presented lipids as the proportion of graded laboratory toxicities (n = 20). Studies of protease inhibitor (PI)- based regimens reported lipids more completely than non-nucleoside reverse transcriptase inhibitor (NNRTI)-based studies. Trials comparing PI-based regimens to NNRTI therapy generally reported graded toxicities or did not include lipids. Within the cohort group, lipid changes appeared lower when presented as median values compared to mean values. Use of grade 3 or higher lipid elevations as the reporting method minimized impact: only 1/64 (2%) reached this threshold. In contrast, reporting outcomes as proportion not at goal per National Cholesterol Education Program (NCEP) Guidelines revealed rates of 23% for triglycerides and 39% for HDL cholesterol. The Framingham risk-prediction model predicted an elevated 10 year risk of cardiovascular disease in 12%. Lipid reporting approaches vary considerably among published ART trials. Implementing a standard approach to reporting lipids including use of NCEP Guidelines and the Framingham risk-prediction model may provide more useful data for clinicians.

To assess the usage, knowledge and attitudes of Patients Living with HIV with respect to supplements. A questionnaire was mailed to people living with HIV via HIV/AIDS organizations in Ontario and distributed to those attending the HIV-clinic of the University Health Network. The survey was completed by 312 subjects (95 female, 207 male). Self-rated health status was considered fair/good in 77.5% and excellent in 15.4% of participants. Vitamin/mineral supplement was used by 75.6%. Main reasons to take supplements were to: prolong life (56.1%); treat HIV-related conditions (19.9%); increase energy level (42.6%) and to boost immunity (36.5%). Among participants, 54.2% were somewhat familiar with supplements, 44.7% trusted the information on the labels and 28.2% felt that if a supplement is available for sale, it is safe. Supplements were mostly purchased at pharmacies (45.5%) and health food stores (30.1%). Only 25.9% and 27.9% of participants discussed their use of supplements with their HIV or family doctor respectively. Supplements are frequently used by people living with HIV without consulting their doctors. Current research has not shown a clear benefit from micronutrient supplementation and with the possible potential drug interactions, people living with HIV will need nutrition education regarding supplement usage and should report their use to their physicians.

Acquired immunodeficiency syndrome (AIDS) is a major public health problem worldwide. This study was performed to explore the feasibility of vertical transmission of human immunodeficiency virus-1 (HIV-1) gag gene via oocyte. The recombinant plasmid (pIRES2-EGFP-gag) was injected into mouse ovaries to transfect germ cells. Induction of superovulation and then animal mating were performed to collect oocytes and two-cell embryos. Positive FISH signals for HIV-1 gag DNA were detected in the nuclei of oocytes and embryos, and in chromosomes of mature oocytes, indicated integration of the gene into the oocyte genome and gene replication in the embryo. HIV-1 gag cDNA positive bands detected by RT-PCR in oocytes and embryos indicated successful gene transcription, while positive immunofluorescence signals for HIV-1 gag protein indicated successful translation in both oocytes and embryos. The HIV-1 gag gene was transmitted vertically to the next generation via oocytes and it retained its function in replication, transcription and translation following at least one mitotic division in embryos.