The changing picture of the HIV/AIDS epidemic

EcoHIV infection of mice establishes latent viral reservoirs in T cells and active viral reservoirs in macrophages that are sufficient for induction of neurocognitive impairment

Suppression of HIV replication by antiretroviral therapy (ART) or host immunity can prevent AIDS but not other HIV-associated conditions including neurocognitive impairment (HIV-NCI). Pathogenesis in HIV-suppressed individuals has been attributed to reservoirs of latent-inducible virus in resting CD4+ T cells. Macrophages are persistently infected with HIV but their role as HIV reservoirs in vivo has not been fully explored. Here we show that infection of conventional mice with chimeric HIV, EcoHIV, reproduces physiological conditions for development of disease in people on ART including immunocompetence, stable suppression of HIV replication, persistence of integrated, replication-competent HIV in T cells and macrophages, and manifestation of learning and memory deficits in behavioral tests, termed here murine HIV-NCI. EcoHIV established latent reservoirs in CD4+ T lymphocytes in chronically-infected mice but could be induced by epigenetic modulators ex vivo and in mice. In contrast, macrophages expressed EcoHIV constitutively in mice for up to 16 months; murine leukemia virus (MLV), the donor of gp80 envelope in EcoHIV, did not infect macrophages. Both EcoHIV and MLV were found in brain tissue of infected mice but only EcoHIV induced NCI. Murine HIV-NCI was prevented by antiretroviral prophylaxis but once established neither persistent EcoHIV infection in mice nor NCI could be reversed by long-acting antiretroviral therapy. EcoHIV-infected, athymic mice were more permissive to virus replication in macrophages than were wild-type mice, suffered cognitive dysfunction, as well as increased numbers of monocytes and macrophages infiltrating the brain. Our results suggest an important role of HIV expressing macrophages in HIV neuropathogenesis in hosts with suppressed HIV replication.

HIV treatment adherence and sexual functioning

To our knowledge, no studies have considered the bidirectional relationship between HIV infected patients' social/sexual lives and HAART adherence. To determine it's potential impact the study sample consisted of 135 men starting HAART and being followed for 6 months. Twenty percent of men enrolled in the study self-reported non-adherence. Non-adherent patients reported a greater number and severity of adverse effects such as gastrointestinal and body changes. All participants were aware of these risks, requested support, and were advised by the health care providers. As many as 26% of the HIV infected men, at the second visit, reported sexual dysfunction and none received information regarding the possibility of this side effect. Of importance, patients reporting sexual dysfunction, were more likely to report not being fully adherent to the medication (RR=2.46 95% CI 1.3-4.7; P=0.04). Of most concern, none of the men reported looking for medical advice.

Bacterial lipopolysaccharide enhances cardiac dysfunction but not retroviral replication in murine AIDS: roles of macrophage infiltration and toll-like receptor 4 expression

Cardiovascular disease is an important complication of human immunodeficiency virus/acquired immune deficiency syndrome (AIDS), but the mechanism(s) involved are poorly understood. Although co-infecting pathogens have been implicated as an important factor in AIDS progression, no studies have investigated these interactions in cardiac tissue. We recently demonstrated that the murine AIDS model (LPBM5 retroviral infection) mimics human immunodeficiency virus-related cardiac dysfunction and pathology. We tested the hypothesis that subseptic lipopolysaccharide exposure (LPS) would enhance LPBM5 progression and exacerbate cardiovascular dysfunction during murine AIDS development. LPS (5 mg/kg, Escherichia coli 0111:B4) was administered at 1, 6, and 8 weeks during LPBM5 infection, and cardiac performance was evaluated at 10 weeks using noninvasive echocardiography. LPS alone had no significant effects, whereas it amplified abnormalities in cardiac structure and function observed in murine AIDS. Cardiac dysfunction was associated with selective increases in nonfocal infiltration of CD68(+) cells and correlated with the extent of cardiac dysfunction. Retroviral progression and cardiac retroviral content remained unaltered, but cardiac toll-like receptor 4 was increased in retrovirus + LPS. We provide first-time evidence of multipathogen enhancements to retrovirus-related cardiac complications and implicate innate immune responses, not co-pathogen-induced retroviral replication, as the primary mechanism in this setting.

Cardiovascular complications of human immunodeficiency virus infection

The heart and great vessels are not the sites most frequently affected by opportunistic infections and neoplastic processes in patients with acquired immune deficiency syndrome (AIDS). However, cardiovascular complications occur in a significant number of such patients and are the immediate cause of death in some. The spectrum of cardiovascular complications of AIDS that may be depicted at imaging includes dilated cardiomyopathy, pericardial effusion, human immunodeficiency virus-associated pulmonary hypertension, endocarditis, thrombosis, embolism, vasculitis, coronary artery disease, aneurysm, and cardiac involvement in AIDS-related tumors. To aid accurate diagnosis and appropriate treatment planning, radiologists should be familiar with the imaging appearance of each of these complications.

Complications musculaires de l’infection par le virus de l’immunodéficience humaine (VIH) à l’ère des trithérapies

Introduction of highly active antiretroviral therapy (HAART) has dramatically modified the natural history of HIV disease, but lengthening the survival of HIV-infected individuals has been associated with an increasing prevalence of iatrogenic conditions. Muscular complications of HIV infection are classified as follows: (1) HIV-associated myopathies and related conditions including polymyositis, inclusion-body myositis, nemaline myopathy, diffuse infiltrative lymphocytosis syndrome (DILS), HIV-wasting syndrome, vasculitis, myasthenic syndromes, and chronic fatigue; (2) iatrogenic conditions including mitochondrial myopathies, HIV-associated lipodystrophy syndrome, and immune restoration syndrome; (3) opportunistic infections and tumor infiltrations of skeletal muscle; and (4) rhabdomyolysis. These features are described in the present review.

Skeletal muscle involvement in human immunodeficiency virus (HIV)-infected patients in the era of highly active antiretroviral therapy (HAART)

Skeletal muscle involvement can occur at all stages of human immunodeficiency virus (HIV) infection, and may represent the first manifestation of the disease. Myopathies in HIV-infected patients are classified as follows: (1) HIV-associated myopathies and related conditions, including HIV polymyositis, inclusion-body myositis, nemaline myopathy, diffuse infiltrative lymphocytosis syndrome (DILS), HIV-wasting syndrome, vasculitic processes, myasthenic syndromes, and chronic fatigue; (2) muscle complications of antiretroviral therapy, including zidovudine and toxic mitochondrial myopathies related to other nucleoside-analogue reverse-transcriptase inhibitors (NRTIs), HIV-associated lipodystrophy syndrome, and immune restoration syndrome related to highly active antiretroviral therapy (HAART); (3) opportunistic infections and tumor infiltrations of skeletal muscle; and (4) rhabdomyolysis. Introduction of HAART has dramatically modified the natural history of HIV disease by controlling viral replication, but, in turn, lengthening of the survival of HIV-infected individuals has been associated with an increasing prevalence of iatrogenic conditions.

AIDS-related vasculopathy: evidence for oxidative and inflammatory pathways in murine and human AIDS

Increased life expectancy of human immunodeficiency virus (HIV)-positive patients has led to evidence of complications apparently not directly related to immunodeficiency or opportunistic infection, including increased cardiovascular risk. We tested the hypothesis that vascular dysfunction occurs in the murine acquired immune deficiency syndrome (AIDS) model and evaluated potential mechanisms in murine AIDS tissues and relevant human HIV/AIDS vascular tissues. We also investigated endothelial activation and/or endothelial protein nitration and their association with time-dependent vascular dysfunction. At 1 and 5 wk of murine AIDS, statistically significant decreases in KCl contractility and time-dependent contractile deficits in response to phenylephrine were observed. The maximal response (E(max)) was reduced by approximately 40% at 10 wk, and EC(50) values were significantly changed: 102 +/- 7.3 ng for control vs. 190 +/- 37 and 130 +/- 22 ng at 5 and 10 wk, respectively (P < 0.05). Endothelium-dependent relaxation to ACh was decreased (EC(50) = 120 +/- 27 and 343 +/- 94 nM for control and at 10 wk, respectively), whereas the response to an exogenous nitric oxide donor, sodium nitroprusside, remained unchanged, suggesting a specific endothelial dysfunction. Histochemical investigations of the same vascular tissues as well as corresponding coronary endothelium showed an increase in protein 3-nitrotyrosine, intercellular adhesion molecule, and nitric oxide synthase isoforms 2 and 3. These findings were corroborated in concurrent experiments in a cohort of well-cataloged human cardiac microvascular tissues. We have demonstrated, for the first time, a specific functional vasculopathy with endothelial involvement in a murine model of AIDS that was also associated with and correlated to increased oxidative stress and specific endothelial activation. This finding was echoed in a relevant population of human HIV/AIDS patients. Research into sources and intracellular targets of oxidants in this disease could provide important mechanistic insights and may reveal new therapeutic opportunities for this increasingly important cardiovascular disease state.

Partial immune reconstitution following highly active antiretroviral therapy: can adjuvant interleukin-2 fill the gap?

Highly active antiretroviral therapy (HAART) induces a substantial control of HIV viral replication, but it allows for only a partial immune reconstitution, thus prompting the rationale for the adjuvant use of immunomodulants. Based on its in vitro action as a major T cell growth factor, interleukin (IL)-2 has now been extensively investigated for its potential to correct the HIV-driven immune deficiencies, possibly translating into immunological control over HIV infection. Specific immunological end points have thus far been addressed within extensive Phase I/II trials, disclosing a broad insight into several aspects of the IL-2-mediated immune reconstitution allowing for interesting clinical speculation. Indeed, preliminary results indicate that adjuvant IL-2 induces a significant CD4 cell rescue in patients with no immune recovery following long-term HAART, thus standing as a valid and safe therapeutic option for these patients. Furthermore, in these patients, the IL-2-mediated immune reconstitution is characterized by a rise in both peripheral turnover and de novo T cell synthesis, with reversion of the skewed HIV-driven immunophenotypic pattern, a substantial increase in IL-7 production and in several markers of immune function. Combined, these findings indicate IL-2 has a beneficial effect in correcting the severe disruption in T cell homeostasis induced by HIV, through the interaction with T cells and cytokine microenvironment. However, whether or not these immunological effects translate into an actual immunological competency and therefore clinical benefit, still awaits demonstration from ongoing large, controlled clinical studies.

Is unsafe sexual behaviour increasing among HIV-infected individuals?

BACKGROUND

The number of new diagnoses of HIV infection is rising in the northwestern hemisphere and it is becoming increasingly important to understand the mechanisms behind this trend.

OBJECTIVE

To evaluate whether reported unsafe sexual behaviour among HIV- infected individuals is changing over time.

DESIGN

Participants in the Swiss HIV Cohort Study were asked about their sexual practices every 6 months for 3 years during regular follow-up of the cohort beginning on 1 April 2000.

METHODS

: Logistic regression models were fit using generalized estimating equations assuming a constant correlation between responses from the same individual.

RESULTS

At least one sexual behaviour questionnaire was obtained for 6545 HIV-infected individuals and the median number of questionnaires completed per individual was five. There was no evidence of an increase in reported unsafe sex over time in this population [odds ratio (OR), 1.0; 95% confidence interval (CI), 0.96-1.05]. Females (OR, 1.38; 95% CI, 1.19-1.60), 15-30 year olds (OR, 1.26; 95% CI, 1.09-1.47), those with HIV-positive partners (OR, 12.58; 95% CI, 10.84-14.07) and those with occasional partners (OR, 3.25; 95% CI, 2.87-3.67) were more likely to report unsafe sex. There was no evidence of a response bias over time, but individuals were less willing to leave questions about their sexual behaviour unanswered or ambiguous (OR, 0.93; 95% CI, 0.90-0.97).

CONCLUSIONS

There was no evidence of a trend in unsafe sex behaviour over time. However, several subgroups were identified as being more likely to report unsafe sex and should be targeted for specific interventions.

Enfermedad cardiovascular sintomática en pacientes infectados por el virus de la inmunodeficiencia humana que reciben tratamiento antirretroviral de gran actividad

BACKGROUND AND OBJECTIVE

Our goal was to assess the main characteristics of cardiovascular disease in HIV-infected patients on highly active antiretroviral therapy (HAART).

PATIENTS AND METHOD

Retrospective analysis of the clinico-epidemiological characteristics of 16 HIV-infected patients treated with HAART who had suffered a cardiovascular event from a 1,459 patients' cohort.

RESULTS

Clinical presentation of cardiovascular disease was an acute coronary syndrome in 12 cases, ischemic stroke in 2 and peripheral vascular disease in 2. Patients included in the study had a mean of 3.2 cardiovascular risk factors, smoking and low HDL levels being the more prevalent risk factors. Eight (50%, 95% CI, 25-75%) patients fulfilled the criteria of metabolic syndrome. The mean CD4 count was 548 x 10(6)/l.

CONCLUSIONS

HIV-infected patients on HAART ha-ve a high cardiovascular risk. A strict management of modifiable risk factors must be warranted in these patients.

Predictors of cardiac morbidity and related mortality in children with acquired immunodeficiency syndrome

OBJECTIVES

The aim of this study was to determine the prevalence of cardiovascular dysfunction and its predictors in children with acquired immunodeficiency syndrome (AIDS).

BACKGROUND

Cardiovascular manifestations are common among children with AIDS but may be clinically occult.

METHODS

We reviewed the medical records, echocardiograms, electrocardiograms, and Holter monitor studies of 68 children with AIDS. We tested clinical and demographic characteristics at the time of AIDS diagnosis for their ability to predict serious cardiac events, death, and cardiac death.

RESULTS

The median time from AIDS diagnosis to death or end of follow-up was 1.0 year (range, 1 week to 7.9 years). Nineteen patients (28%) experienced serious cardiac events after AIDS diagnosis. Of 43 patients who died, 15 (35%) had cardiac dysfunction. Multivariable analyses revealed that recurrent bacterial infections, wasting, encephalopathy, male gender, and an earlier year of AIDS diagnosis were predictors of serious cardiac events (relative risk [RR] = 9.3, 6.9, 4.7, 4.1, and 0.76, respectively, p < 0.05). Wasting, encephalopathy, a low age-adjusted CD4 count, a low age-adjusted immunoglobulin G (IgG) level, and an earlier year of AIDS diagnosis increased the risk of all-cause mortality (RR = 8.9, 5.1, 2.7, 0.82, and 0.8, respectively, p <or= 0.02). Male gender, a low age-adjusted CD4 count, and a low age-adjusted IgG level increased the risk for cardiac death (RR = 16.9, 4.2, and 0.68, respectively, p <or= 0.05).

CONCLUSIONS

Serious cardiac events and cardiac death are common among children with AIDS. Factors such as recurrent bacterial infections, wasting, encephalopathy, male gender, low CD4 and IgG levels, and an earlier year at AIDS diagnosis may identify high-risk patients.