Impact of protease inhibitors and other antiretroviral treatments on acquired immunodeficiency syndrome survival in San Francisco, California, 1987-1996

Switching from a Non-Protease inhibitor-Based Regimen To the Fixed Dose Combination of Darunavir/Cobicistat/Emtricitabine/Tenofovir Alafenamide in Clinical Practice

Background

Methods

Results

Conclusion

Incidence of first and second primary cancers diagnosed among people with HIV, 1985-2013: a population-based, registry linkage study

BACKGROUND

Cancer survivors are at increased risk for subsequent primary cancers. People living with HIV are at increased risk for AIDS-defining and non-AIDS-defining cancers, but little is known about their risk of first versus second primary cancers. We identified first and second primary cancers that occurred in above population expected numbers among people diagnosed with HIV in San Francisco, and compared first and second cancer incidence across five time periods that corresponded to important advances in antiretroviral therapy.

METHODS

In this population-based study, we used the San Francisco HIV/AIDS case registry to identify people aged 16 years and older who were diagnosed with HIV/AIDS in San Francisco (CA, USA) between Jan 1, 1990, and Dec 31, 2010. We computer-matched records from the registry with the California Cancer Registry to identify primary cancers diagnosed between Jan 1, 1985, and Dec 31, 2013. We calculated year, age, sex, and race adjusted standardised incidence ratios with exact 95% CIs and trends in incidence of first and second AIDS-defining and non-AIDS-defining cancers from 1985 to 2013.

FINDINGS

Of the 22 623 people diagnosed with HIV between Jan 1, 1990, and Dec 31, 2010, we identified 5655 incident primary cancers. We excluded 48 cancers with invalid cancer sequence numbers and 1062 in-situ anal cancers, leaving 4545 incident primary cancers, comprising 4144 first primary cancers, 372 second primary cancers, 26 third primary cancers, and three fourth or later primary cancers. First primary cancer standardised incidence ratios were elevated for Kaposi sarcoma (127, 95% CI 121-132), non-Hodgkin lymphoma (17·2, 16·1-18·4), invasive cervical cancer (8·0, 4·1-11·9), anal cancer (46·7, 39·7-53·6), vulvar cancer (13·3, 6·1-20·6), Hodgkin's lymphoma (10·4, 8·4-12·5), eye and orbit cancer (4·2, 1·4-6·9), lip cancer (3·8, 1·3-6·2), penile cancer (3·8, 1·4-6·1), liver cancer (3·0, 2·3-3·7), miscellaneous cancer (2·3, 1·7-3·0), testicular cancer (2·0, 1·4-2·6), tongue cancer (1·9, 1·1-2·7), and lung cancer (1·3, 95% CI 1·1-1·6). Second primary cancer risks were increased for Kaposi sarcoma (28·0, 95% CI 20·2-35·9), anal cancer (17·0, 10·2-23·8), non-Hodgkin lymphoma (11·1, 9·3-12·8), Hodgkin's lymphoma (5·4, 1·1-9·7), and liver cancer (3·6, 1·4-5·8). We observed lower first primary cancer standardised incidence ratios for prostate cancer (0·6, 95% CI 0·5-0·7), colon cancer (0·6, 0·4-0·8), and pancreatic cancer (0·6, 0·3-1·0), and lower second primary cancer standardised incidence ratios for testicular cancer (0·3, 0·0-0·9), kidney cancer (0·4, 0·0-0·9), and prostate cancer (0·6, 0·2-0·9). First and second primary AIDS-defining cancer incidence declined, and second primary non-AIDS-defining cancer incidence increased over time.

INTERPRETATION

Because of an increased risk for both first and second primary cancers, enhanced cancer prevention, screening, and treatment efforts are needed for people living with HIV both before and after initial cancer diagnosis.

FUNDING

University of California San Francisco and US Centers for Disease Control and Prevention.

Non-proteolytic functions of microbial proteases increase pathological complexity

Proteases are enzymes that catalyse hydrolysis of peptide bonds thereby controlling the shape, size, function, composition, turnover and degradation of other proteins. In microbes, proteases are often identified as important virulence factors and as such have been targets for novel drug design. It is emerging that some proteases possess additional non‐proteolytic functions that play important roles in host epithelia adhesion, tissue invasion and in modulating immune responses. These additional “moonlighting” functions have the potential to obfuscate data interpretation and have implications for therapeutic design. Moonlighting enzymes comprise a subcategory of multifunctional proteins that possess at least two distinct biological functions on a single polypeptide chain. Presently, identifying moonlighting proteins relies heavily on serendipitous empirical data with clues arising from proteins lacking signal peptides that are localised to the cell surface. Here, we describe examples of microbial proteases with additional non‐proteolytic functions, including streptococcal pyrogenic exotoxin B, PepO and C5a peptidases, mycoplasmal aminopeptidases, mycobacterial chaperones and viral papain‐like proteases. We explore how these non‐proteolytic functions contribute to host cell adhesion, modulate the coagulation pathway, assist in non‐covalent folding of proteins, participate in cell signalling, and increase substrate repertoire. We conclude by describing how proteomics has aided in moonlighting protein discovery, focusing attention on potential moonlighters in microbial exoproteomes.

Migration patterns among Floridians with AIDS, 1993-2007: implications for HIV prevention and care

OBJECTIVES

To characterize migration patterns among people diagnosed as having and who died of acquired immunodeficiency syndrome (AIDS) from 1993 to 2007 because migrating to a new community can disrupt human immunodeficiency virus/AIDS care delivery and patients' adherence to care and affect migrants' social services and healthcare needs.

METHODS

Florida AIDS surveillance data were used to describe patterns of migration among people diagnosed as having and who died of AIDS from 1993 to 2007. Individual and community characteristics were compared between residence at the time of AIDS diagnosis and residence at the time of death by type of migration.

RESULTS

Of 31,816 people in the cohort, 2510 (7.9%) migrated to another county in Florida and 1306 (4.1%) migrated to another state. Interstate migrants were more likely to be men, 20 to 39 years old, non-Hispanic white, and born in the United States, to have had a transmission mode of injection drug use (IDU) or men who have sex with men with IDU (MSM&IDU), and to have been diagnosed before 1999. Intercounty migrants were more likely to be non-Hispanic white, younger than 60 years, have had a transmission mode of MSM, IDU, or MSM&IDU, have higher CD4 counts/percentages, and to have lived in areas with low levels of poverty or low physician density. There was a small net movement from urban to rural areas within the state.

CONCLUSIONS

A sizable percentage of people, particularly younger people and people with a transmission mode of IDU and IDU&MSM, migrated at least once between the time of their AIDS diagnosis and death. This has important implications for care and treatment, as well as efforts to prevent the disease. Further research is needed to explore barriers and facilitators to access to care upon migration and to assess the need for programs to help people transfer their human immunodeficiency virus/AIDS care, ensuring continuity of care and adherence.

Endosomal trafficking of nanoformulated antiretroviral therapy facilitates drug particle carriage and HIV clearance

Limitations of antiretroviral therapy (ART) include poor patient adherence, drug toxicities, viral resistance, and failure to penetrate viral reservoirs. Recent developments in nanoformulated ART (nanoART) could overcome such limitations. To this end, we now report a novel effect of nanoART that facilitates drug depots within intracellular compartments at or adjacent to the sites of the viral replication cycle. Poloxamer 407-coated nanocrystals containing the protease inhibitor atazanavir (ATV) were prepared by high-pressure homogenization. These drug particles readily accumulated in human monocyte-derived macrophages (MDM). NanoATV concentrations were ∼1,000 times higher in cells than those that could be achieved by the native drug. ATV particles in late and recycling endosome compartments were seen following pulldown by immunoaffinity chromatography with Rab-specific antibodies conjugated to magnetic beads. Confocal microscopy provided cross validation by immunofluorescent staining of the compartments. Mathematical modeling validated drug-endosomal interactions. Measures of reverse transcriptase activity and HIV-1 p24 levels in culture media and cells showed that such endosomal drug concentrations enhanced antiviral responses up to 1,000-fold. We conclude that late and recycling endosomes can serve as depots for nanoATV. The colocalization of nanoATV at endosomal sites of viral assembly and its slow release sped antiretroviral activities. Long-acting nanoART can serve as a drug carrier in both cells and subcellular compartments and, as such, can facilitate viral clearance.

IMPORTANCE

The need for long-acting ART is significant and highlighted by limitations in drug access, toxicity, adherence, and reservoir penetrance. We propose that targeting nanoformulated drugs to infected tissues, cells, and subcellular sites of viral replication may improve clinical outcomes. Endosomes are sites for human immunodeficiency virus assembly, and increasing ART concentrations in such sites enhances viral clearance. The current work uncovers a new mechanism by which nanoART can enhance viral clearance over native drug formulations.

Alcohol and HIV: Experimental and Clinical Evidence of Combined Impact on the Lung

Despite antiretroviral therapy, lung disease is a leading cause of death in individuals infected with human immunodeficiency virus type 1 (HIV). Individuals infected with HIV are susceptible to serious bacterial and viral infections, such as pneumococcus and influenza, which are particularly problematic for lung health, resulting in lung injury. Additionally, HIV-infected individuals are susceptible to a number of pulmonary diseases for unknown reasons. Alcohol, the most commonly abused drug in the world, continues to exact an enormous toll on morbidity and mortality in individuals living with HIV. Chronic alcohol abuse has been shown to affect lung immunity, resulting in significant lung injury. There is a paucity of literature on the additive effects of HIV and alcohol, two diseases of immune senescence, in the lung. This chapter begins by discussing the latest literature evaluating the epidemiology of HIV, alcohol use, and lung health focusing on two prevalent infections, tuberculosis and pneumococcal pneumonia. In parallel, we discuss the interactions of alcohol and HIV on the risk for acute lung injury and subsequent morbidity and mortality. We then discuss the pathophysiology of how these two diseases of immune dysfunction affect the lung, with a focus on the oxidative stress, alveolar macrophage host immune capacity, and immunomodulatory role of zinc in the airway. Finally, we review the latest literature on how HIV and alcohol affect other pulmonary disorders including chronic obstructive pulmonary disease, pulmonary hypertension, and lung cancer.

Rural AIDS diagnoses in Florida: changing demographics and factors associated with survival

PURPOSE

To compare demographic characteristics and predictors of survival of rural residents diagnosed with acquired immunodeficiency syndrome (AIDS) with those of urban residents.

METHODS

Florida surveillance data for people diagnosed with AIDS during 1993-2007 were merged with 2000 Census data using ZIP code tabulation areas (ZCTAs). Rural status was classified based on the ZCTA's rural-urban commuting area classification. Survival rates were compared between rural and urban areas using survival curves and Cox proportional hazards models controlling for demographic, clinical, and area-level socioeconomic and health care access factors.

FINDINGS

Of the 73,590 people diagnosed with AIDS, 1,991 (2.7%) resided in rural areas. People in the most recent rural cohorts were more likely than those in earlier cohorts to be female, non-Hispanic black, older, and have a reported transmission mode of heterosexual sex. There were no statistically significant differences in the 3-, 5-, or 10-year survival rates between rural and urban residents. Older age at the time of diagnosis, diagnosis during the 1993-1995 period, other/unknown transmission mode, and lower CD4 count/percent categories were associated with lower survival in both rural and urban areas. In urban areas only, being non-Hispanic black or Hispanic, being US born, more poverty, less community social support, and lower physician density were also associated with lower survival.

CONCLUSIONS

In rural Florida, the demographic characteristics of people diagnosed with AIDS have been changing, which may necessitate modifications in the delivery of AIDS-related services. Rural residents diagnosed with AIDS did not have a significant survival disadvantage relative to urban residents.

Community poverty and trends in racial/ethnic survival disparities among people diagnosed with AIDS in Florida, 1993-2004

OBJECTIVES

We described the racial/ethnic disparities in survival among people diagnosed with AIDS in Florida from 1993 to 2004, as the availability of highly active antiretroviral therapy (HAART) became widespread. We determined whether these disparities decreased after controlling for measures of community-level socioeconomic status.

METHODS

We compared survival from all causes between non-Hispanic Blacks and non-Hispanic Whites vis-a-vis survival curves and Cox proportional hazards models controlling for demographic, clinical, and area-level poverty factors.

RESULTS

Racial/ethnic disparities in survival peaked for those diagnosed during the early implementation of HAART (1996-1998) with a Black-to-White hazard ratio (HR) of 1.72 (95% confidence interval [CI] = 1.62, 1.83) for males and 1.40 (95% CI = 1.24, 1.59) for females. These HRs declined significantly to 1.48 (95% CI = 1.35, 1.64) for males and nonsignificantly to 1.25 (95% CI = 1.05, 1.48) for females in the 2002 to 2004 diagnosis cohort. Disparities decreased significantly for males but not females when controlling for baseline demographic factors and CD4 count and percentage, and became nonsignificant in the 2002 to 2004 cohort after controlling for area poverty.

CONCLUSIONS

Area poverty appears to play a role in racial/ethnic disparities even after controlling for demographic factors and CD4 count and percentage.

Predictors of death in Malaysian HIV-infected patients on anti-retroviral therapy

OBJECTIVE

To determine the predictors of death in Malaysian HIV-infected patients undergoing antiretroviral therapy (ART).

METHODS

Data from 845 HIV-infected patients aged ≥ 20 years on ART in a large teaching hospital in Malaysia from 1989 to 2009 were analyzed using Kaplan-Meier and Cox regression analyses.

RESULTS

72.7% of the patients survived. Multivariate Cox regression showed that significant predictors of death were age ≥ 50 years (HR 1.76; 95% CI 1.18-2.64), secondary education (HR 3.57; 95% CI 1.12-11.37), tertiary education (HR 3.57; 95% CI 1.09-11.70), being unemployed (HR 1.49; 95% CI 1.07-2.09), AIDS on initial presentation (HR 5.75; 95% CI 3.29-10.07), single-drug ART (HR 1.84; 95% CI 1.27, 2.66), double-drug ART (HR 1.63; 95% CI 1.19-2.25) and inability to achieve viral load ≤ 50 copies/ml (HR 10.22; 95% CI 7.26-14.37).

CONCLUSION

Every effort needs to be made to ensure that all HIV patients have access to triple drug ART, to lower viral load to ≤ 50 copies/ml and to treat HIV patients before they progress to AIDS as these are significant modifiable predictors of death in Malaysian HIV patients.

The mysteries and demands of HIV care: qualitative analyses of HIV specialists’ views on their expertise

To deepen our understanding of the mysteries and demands associated with HIV care and to inform the debate about HIV specialization, we conducted in-depth interviews with a purposive sample of 20 identified HIV specialists in the San Francisco Bay Area. Participants were from several medical specialties and reported a median of 50% of their time spent in HIV patient care. Through constant comparison, a template of open codes was constructed to identify themes that emerged from the data. Data were analyzed according to the conventions of qualitative research and revealed six interrelated themes: (1) coping with uncertainty and rapid change: being 'comfortable with mystery'; (2) the powerful role of experience; (3) the dual faces of knowledge: 'knowing the patient' and 'knowing the facts'; (4) the dual faces of passion: challenge and calling; (5) stress and burnout; and (6) the relationship between academia and 'the trenches'. The themes underscore the dual dimensions of HIV care: providers must interweave the 'half-baked' science about drug therapies, side effects and drug interactions with the psychosocial and lifestyle factors of the patient. They also provide insight into quantitative findings linking greater HIV experience with better patient outcomes and suggest that providers need skills associated with generalist and specialist training, a phenomenon that argues for a 'special' specialty for HIV care.

Illness meanings of AIDS among women with HIV: merging immunology and life experience

Little attention has been paid to illness meanings held by those with HIV in the presence of highly active antiretroviral therapy (HAART). This article illustrates how elucidating illness meanings might aid our understanding of HAART adherence and other important health behaviors. Using multiple qualitative methods, including in-depth interviews, free lists, and drawings, I explore meanings surrounding the concept of AIDS among women with HIV in New Orleans, Louisiana. Illness meanings of AIDS reflect the women's negotiation of physical, social, and emotional threats posed by HIV. HIV-positive women displace death and stigma away from an HIV diagnosis to an AIDS diagnosis, creating a sense of safety and normalcy for themselves. Women with AIDS diagnoses, however, struggle to construct illness meanings of AIDS that resist its association with ostracism and death. Drawings produced by the women provide rich insights and illustrate the value of drawings as a visual method in exploring illness meanings.

Lopinavir impairs protein synthesis and induces eEF2 phosphorylation via the activation of AMP-activated protein kinase

HIV anti-retroviral drugs decrease protein synthesis, although the underlying regulatory mechanisms of this process are not fully established. Therefore, we investigated the effects of the HIV protease inhibitor lopinavir (LPV) on protein metabolism. We also characterized the mechanisms that mediate the effects of this drug on elongation factor-2 (eEF2), a key component of the translational machinery. Treatment of C2C12 myocytes with LPV produced a dose-dependent inhibitory effect on protein synthesis. This effect was observed at 15 min and was maintained for at least 4 h. Mechanistically, LPV increased the phosphorylation of eEF2 and thereby decreased the activity of this protein. Increased phosphorylation of eEF2 was associated with increased activity of its upstream regulators AMP-activated protein kinase (AMPK) and eEF2 kinase (eEF2K). Both AMPK and eEF2K directly phosphorylated eEF2 in an in vitro kinase assay suggesting two distinct paths lead to eEF2 phosphorylation. To verify this connection, myocytes were treated with the AMPK inhibitor compound C. Compound C blocked eEF2K and eEF2 phosphorylation, demonstrating that LPV affects eEF2 activity via an AMPK-eEF2K dependent pathway. In contrast, incubation of myocytes with rottlerin suppressed eEF2K, but not eEF2 phosphorylation, suggesting that eEF2 can be regulated independent of eEF2K. Finally, LPV did not affect PP2A activity when either eEF2 or peptide was used as the substrate. Collectively, these results indicate that LPV decreases protein synthesis, at least in part, via inhibition of eEF2. This appears regulated by AMPK which can act directly on eEF2 or indirectly via the action of eEF2K.

Atazanavir: its role in HIV treatment

Azatanavir is a protease inhibitor (PI) approved for the treatment of HIV-1 infection. Atazanavir is a substrate and inhibitor of cytochrome P450 isozyme 3A and an inhibitor and inducer of P-glycoprotein. It has similar virologic efficacy as efavirenz and ritonavir-boosted lopinavir in antiretroviral-naive individuals. Its impact on lipids is less than other PIs and it is suitable for those in whom hyperlipidemia is undesirable. Ritonavir boosting of atazanavir enhances the bioavailability of atazanavir but may result in some elevation of lipids and is recommended for treatment-experienced patients and those receiving efavirenz or tenofovir. Ritonavir-boosted atazanavir has similar antiviral activity as ritonavir-boosted lopinavir in both antiretroviral therapy-naive and -experienced patients. Atazanavir causes unconjugated bilirubinemia in over 40% of patients but results in less than 2% discontinuations. Atazanavir is licensed for once-daily use and atazanavir/ritonavir competes with lopinavir/ritonavir as the most commonly prescribed PI.

Differential improvement in survival among patients with AIDS after the introduction of HAART

We explored changes in the survival of patients with AIDS (PWA) according to the availability of antiretroviral drugs (1994-2002). We tested whether changes in the hazard ratio of progression to death (HR) have been homogeneous among various groups of PWA. We included 4158 PWA diagnosed in Paris, notified to the French National Surveillance Institute by 2002. Four calendar periods were defined: monotherapy (1994-95), bitherapy-HAART transition (1996), early HAART (1997-99), late HAART (2000-October 2002). HR were calculated with Cox models, including the calendar period, modelled as a time dependent covariate. Models were stratified by age, transmission category, CD4 cell count, and AIDS-defining illnesses (ADI) group. Cumulative survival at 60 months increased from 44.0% (before July 1996) to 75.6% (after July 1996) and median survival increased from 31.9 months to >76 months. Adjusted HR reached a minimum in the late HAART period (HR 0.22, 95% CI: 0.19-0.26). No difference in the decrease of the HR has been found by age. HR decreased and was marked during the late HAART period across all HIV transmission categories, including intravenous drug use. HR decreased significantly for all ADIs groups, including tumours. Among PWA diagnosed with tuberculosis, the HR decreased significantly only in the late HAART period. HR decrease was stronger for PWA with a CD4 cell count < or =200/mm(3). Substantial improvements in survival after the introduction of HAART were found for all PWA but varied by specific ADIs and the degree of immunosuppression.

Protease inhibitors and their peptidomimetic derivatives as potential drugs

Precise spatial and temporal regulation of proteolytic activity is essential to human physiology. Modulation of protease activity with synthetic peptidomimetic inhibitors has proven to be clinically useful for treating human immunodeficiency virus (HIV) and hypertension and shows potential for medicinal application in cancer, obesity, cardiovascular, inflammatory, neurodegenerative diseases, and various infectious and parasitic diseases. Exploration of natural inhibitors and synthesis of peptidomimetic molecules has provided many promising compounds performing successfully in animal studies. Several protease inhibitors are undergoing further evaluation in human clinical trials. New research strategies are now focusing on the need for improved comprehension of protease-regulated cascades, along with precise selection of targets and improved inhibitor specificity. It remains to be seen which second generation agents will evolve into approved drugs or complementary therapies.

Coronary Heart Disease Risks and Lifestyle Behaviors in Persons With HIV Infection

Metabolic complications such as HIV-associated lipodystrophy syndrome are common in patients with HIV-1 infection who are taking highly active antiretroviral therapy. HIV-associated lipodystrophy syndrome is characterized by dyslipidemia, fat redistribution, and altered glucose metabolism; however, there has been little study of relationships between these risk factors for coronary heart disease (CHD) and lifestyle risks. The aims of this study were to (a) describe the physical activity levels, nutrition habits, and smoking behaviors of persons with HIV-1 infection; (b) describe their CHD risks and estimate 10-year risk for CHD outcomes; and (c) examine the relationship between potentially modifiable lifestyle behaviors and risk factors for atherosclerotic cardiovascular disease in persons with HIV-1 infection receiving highly active antiretroviral therapy. Variables included lipid profile and other metabolic indices, body fat distribution, body mass index, blood pressure, and lifestyle behaviors (physical activity, dietary habits, smoking). A cross-sectional design and convenience sampling (n = 95) was used. Participants had multiple modifiable risk factors: 20% had a 10-year risk of 10% or higher of developing CHD. Results underscore the need for health promotion interventions to target lifestyle risks in persons with HIV-1 infection taking highly active retroviral therapy.

Highly active antiretroviral therapy access and neurological complications of human immunodeficiency virus infection: Impact versus resources in Brazil

Currently, there are almost 600,000 human immunodeficiency virus (HIV)-infected individuals in Brazil. From 1984 to 2004, 362,364 acquired immunodeficiency virus (AIDS) cases were officially reported and 155,000 patients are under highly active antiretroviral therapy (HAART) treatment. Like in developed countries, universal access to treatment in Brazil has definitively changed both mortality and morbidity of AIDS. Today, the median survival time is 58 months, with a 2-year survival of 63%, versus 18 months before HAART. As expected, the incidence of nervous system opportunistic infectious diseases and tumors has also decreased in Brazil. However, few Brazilian reports about neurological manifestations of HIV infection are available, particularly after the beginning of more effective antiretroviral therapy. Autopsy series report that toxoplasmosis is the most prevalent neurological disease, followed by cryptococcosis and HIV encephalitis. A much lower incidence of progressive multifocal leukoencephalopathy has been described in Brazil than in reports from developed countries. A possibility for this discrepancy could be differences in terms of JC virus (JCV) isolates or even the interactions between JCV and local HIV strains. Some particularities about the involvement of the nervous system in Brazilian patients are worthy of note, such as the occurrence of central nervous system involvement in chronic Chagas' disease in patients with AIDS, and the concomitance of leprosy and HIV infection. National surveillance of neurological manifestations of HIV infection is needed to ascertain the real impact of HAART on nervous system diseases associated with AIDS in Brazil.

HIV antiretroviral agents inhibit protein synthesis and decrease ribosomal protein S6 and 4EBP1 phosphorylation in C2C12 myocytes

Combined antiretroviral drug regimens have promoted clinical, immunologic, and virologic improvements in AIDS patients. Nevertheless, these therapies are associated with derangements in lipid and carbohydrate metabolism. In this study, we examined the effects of a representative protease inhibitor (nelfinavir), a nonnucleoside reverse transcriptase inhibitor (nevirapine), and a nucleoside reverse transcriptase inhibitor (zidovudine) on protein synthesis in skeletal muscle cells. To examine these processes, C2C12 myocytes were treated with increasing concentrations of nelfinavir, nevirapine, or zidovudine for 1 or 2 days, and rates of protein synthesis were determined by measuring [35S]methionine/cysteine incorporation into cellular proteins. Treatment of myocytes with therapeutic concentrations of nelfinavir, nevirapine, or zidovudine for 48 hr decreased protein synthesis by 14-20%. An approximately 60% decline was observed in cells treated with higher concentrations of nevirapine or nelfinavir. In contrast, the basal rate of protein synthesis was not affected when cells were incubated with these compounds for 24 hr. Therapeutic concentrations of nelfinavir and nevirapine did not impair the anabolic effect of insulin on protein synthesis. However, zidovudine suppressed the stimulatory effect of insulin. The decreased protein synthesis induced by nelfinavir and zidovudine was associated with decreases in the phosphorylation of the S6 ribosomal protein (rpS6) and the repressor binding protein 4EBP1, while the inhibitory effect of nevirapine was mainly associated with a decline in phosphorylated 4EBP1. In conclusion, nelfinavir, nevirapine, and zidovudine treatments decreased protein synthesis in myocytes and this effect was correlated with a reduction in the phosphorylation level of proteins that regulate translation initiation.

Prognostic Factors for Survival Differ According to CD4+ Cell Count Among HIV-Infected Injection Drug Users

To identify prognostic indicators of survival at different CD4 cell levels, independent of highly active antiretroviral therapy (HAART), among injection drug users (IDUs). A community-recruited cohort of injection drug users followed semiannually from 1988 through 2000. Five partially overlapping subcohorts were defined by when participants first reached a CD4 cell level of 351 to 500, 201 to 350, 101 to 200, 51 to 100, or </=50 cells/microL. Prognostic factors were measured at entry into each category. Kaplan-Meier survival estimates for HIV-related death and Cox regression models were constructed by CD4 category. Among the 1030 HIV-infected IDUs, survival improved in the HAART-era with hazard ratios 0.42, 0.36, 0.24, 0.21, and 0.25, respectively, for CD4 cell groups of 500 to 351, 350 to 201, 200 to 101, 100 to 51, and </=50 cells/microL. Shorter survival was associated with prior hospitalization, AIDS, and sexually transmitted disease, with similar effects in the pre-HAART and HAART eras. For the lowest CD4 cell level, prior sepsis or endocarditis, outpatient/emergency room visits, and alcohol use provide additional prognostic value. Survival among HIV-infected IDUs improved since the introduction of HAART, even though utilization of HAART was incomplete. Clinical and behavioral variables provided prognostic information about survival, including substance use indicators.

A structural basis for the acute effects of HIV protease inhibitors on GLUT4 intrinsic activity

Human immunodeficiency virus (HIV) protease inhibitors (PIs) act as reversible noncompetitive inhibitors of GLUT4 with binding affinities in the low micromolar range and are known to contribute to alterations in glucose homeostasis during treatment of HIV infection. As aspartyl protease inhibitors, these compounds all possess a core peptidomimetic structure together with flanking hydrophobic moieties. To determine the molecular basis for GLUT4 inhibition, a family of related oligopeptides containing structural elements found in PIs was screened for their ability to inhibit 2-deoxyglucose transport in primary rat adipocytes. The peptide oxybenzylcarbonyl-His-Phe-Phe-O-ethyl ester (zHFFe) was identified as a potent inhibitor of zero-trans glucose flux with a K(i) of 26 mum. Similar to PIs, transport inhibition by this peptide was acute, noncompetitive, and reversible. Within a Xenopus oocyte expression system, zHFFe acutely and reversibly inhibited GLUT4-mediated glucose uptake, whereas GLUT1 activity was unaffected at concentrations as high as 1 mm. The related photoactivatable peptide zHFF-p-benzoylphenylalanine-[(125)I]Tyr-O-ethyl ester selectively labeled GLUT4 in rat adipocytes and indinavir effectively protected against photolabeling. Furthermore, GLUT4 bound to a peptide affinity column containing the zHFF sequence and was eluted by indinavir. These data establish a structural basis for PI effects on GLUT4 activity and support the direct binding of PIs to the transport protein as the mechanism for acute inhibition of insulin-stimulated glucose uptake.

Indinavir impairs protein synthesis and phosphorylations of MAPKs in mouse C2C12 myocytes

Anti-retroviral therapy promotes clinical, immunologic, and virologic improvement in human immunodeficiency virus-infected patients. Whereas this therapy adversely affects carbohydrate and lipid metabolism, the effects of anti-retroviral drugs on muscle protein synthesis and degradation have not been reported. To examine these processes, we treated C2C12 myocytes with increasing concentrations of the protease inhibitor indinavir for 1 or 2 days. Treatment of myocytes with a therapeutic concentration of indinavir (20 microM) for 24 h decreased basal protein synthesis by 18%, whereas a 42% decline was observed after 48 h. A similar decrement, albeit quantitatively smaller, was detected with other protease inhibitors. Indinavir did not alter the rate of proteolysis. Likewise, indinavir did not impair the anabolic effect of insulin-like growth factor-I on protein synthesis. Mechanistically, indinavir decreased the phosphorylation of the S6 ribosomal protein (rpS6), and this reduction was associated with a decreased phosphorylation of p70S6 kinase and p90rsk as well as the upstream regulators ERK1/2 and MEK1/2. Indinavir also decreased the phosphorylation of Mnk1 and its upstream effectors, p38 MAPK and ERK1/2. Indinavir did not affect the phosphorylation of mTOR or 4E-BP1, but it did decrease the amount of the active eukaryotic initiation factor eIF4G-eIF4E complex. In conclusion, indinavir decreased protein synthesis in myocytes. This decrease was associated with the disruption of the ERK1/2 and p38 MAPK pathways and a reduction in both the level of functional eIF4F complex and rpS6 phosphorylation.

Changes in the transmission dynamics of the HIV epidemic after the wide-scale use of antiretroviral therapy could explain increases in sexually transmitted infections: results from mathematical models

BACKGROUND

Recent increases in bacterial sexually transmitted infections (STI) and risk behavior have coincided with the introduction of antiretroviral therapy (ART) in homosexual communities of industrialized countries. The reasons for these increases are not fully understood.

GOAL

The goal of this study was to understand the various effects of ART on risk behaviors and STI.

OBJECTIVE

The objective of this study was to assess the independent impact of the change in the transmission dynamics of HIV/AIDS as a result of the wide-scale use of ART on a bacterial STI.

STUDY DESIGN

We developed a mathematical model of bacterial STI and treated/untreated HIV/AIDS infection for an open homosexual population. At the individual level, we assume that susceptible and healthy HIV-positive individuals do not increase their risk behavior as a result of ART over time. However, individuals with AIDS, who are successfully treated with ART, can resume sexual activity. The impact of the wide-scale use of ART on risky behavior, STI, and HIV/AIDS was evaluated over a wide range of assumptions on treatment use, ART efficacy, and population characteristics.

RESULTS

Over 10 years, 0% to 55% new bacterial STI could be attributed to the wide-scale use of ART as a result of more modest increases (0-25%) in risky sex occurring at the population level rather than at the individual level. These increases have a negative impact on HIV if coverage is too low. Increasing treatment coverage helps to prevent more HIV infections despite larger increases in risky sex and STI that is predicted to ensue.

CONCLUSION

Taking the differential impact of wide-scale use of ART into account helps to interpret recent behavioral and STI trends. Our results have implications for prevention strategies and for the formulation of public health policies. A better understanding of the differential impact of ART on sexual network over time is required.

HIV prevention in the era of new treatments

Advances in the treatment of HIV disease in recent years have prompted concern that individuals may regard HIV/AIDS as a less serious threat and consequently will be less committed to safer sex practices. This article reviews studies that have been conducted so far to assess the impact of new treatments for HIV on risk perceptions and behaviors among various population groups. Health practitioners need to be alerted to changing attitudes and preventive behaviors in their community stemming from the new treatments. Suggestions are offered to providers of HIV prevention services on how to address the issue of new treatments and the possibility of increasing complacency about safer sex practices.

Relationship-specific unsupportive social interactions and depressive symptoms among women living with HIV/AIDS: direct and moderating effects

Although unsupportive social interactions have demonstrated strong relations with psychological adjustment to illness, little research has been directed at the differential effects of unsupportive interactions from different relationship sources (i.e., family, friends, or a lover/spouse). The present study examines whether the source of unsupportive social interactions has differential main and interactive relations with depressive symptoms among an ethnically diverse sample of women living with HIV/AIDS (N = 146). After imposing demographic controls, unsupportive social interactions from family were found to have a main effect predicting more depressive symptoms. Furthermore, a significant interaction was identified between unsupportive interactions from a lover/spouse and from friends, such that high levels of unsupportive interactions from either or both sources predicted high levels of depressive symptoms. Only when neither source of unsupportive interactions was at a high level were nonclinical levels of depressive symptoms predicted.

Dramatic improvement in survival among adult Brazilian AIDS patients

BACKGROUND

Since the last study of survival time among Brazilian AIDS patients, care has improved steadily, culminating in a controversial policy of universal free access to triple antiretroviral treatment since 1996. This large, national study examined how these changes have impacted survival.

METHODS

Using national data for cases diagnosed in 1995 and 1996, we randomly selected 3930 adult AIDS cases from 18 cities in seven states representing all regions of Brazil. Trained abstracters reviewed medical records, determining dates of diagnosis and death or last contact, exposure category, treatment, and demographics. After review, 2821 cases met the inclusion criteria and were available for Kaplan-Meier and proportional hazards analysis. Data from the earlier study were re-analyzed for comparison.

RESULTS

Median survival was 5 months for cases diagnosed in the 1980s, 18 months for those diagnosed in 1995, and 58 months for those diagnosed in 1996. Predictors of longer survival in univariate analysis included antiretroviral treatment, year of diagnosis, higher education, sexual exposure category, female sex, and Pneumocystis carinii pneumonia prophylaxis. In multivariate analysis, the predictive value of most of these was attenuated or disappeared, leaving antiretroviral treatment as the main predictor of survival.

CONCLUSIONS

Survival time has increased substantially for adult Brazilian AIDS patients. The timing of these gains and analysis of the predictors of survival both indicate antiretroviral treatment as the cause. These findings demonstrate that universal access to antiretroviral treatment in a developing country can produce benefits on the same scale as in richer countries.

Determinants of survival among HIV-infected chronic dialysis patients

Over 100 HIV-infected patients have initiated chronic dialysis at San Francisco General Hospital (SFGH) since 1985. This study employed retrospective analysis to identify determinants of and trends in survival among HIV-infected patients who have initiated chronic dialysis at SFGH from January 1, 1985 to November 1, 2002 (n = 115). Cohort patient survival was compared with survival after an AIDS-opportunistic illness in all HIV-infected patients in San Francisco during the study period. Higher CD4 count (hazard ratio [HR], 0.86 per 50 cells/mm(3) increase; 95% confidence interval [CI], 0.80 to 0.93) and serum albumin (HR, 0.53 per 1 g/dl increase; CI, 0.36 to 0.78) at initiation of dialysis were strongly associated with lower mortality. Survival for those initiating dialysis during the era of highly active antiretroviral therapy (HAART) was 16.1 mo versus 9.4 mo for those initiating dialysis before this time, but this difference was not statistically significant. In adjusted analysis, only a non-statistically significant trend toward improved survival during the HAART era was noted (HR, 0.59; CI, 0.34 to 1.04). By comparison, survival for all HIV-infected patients after an AIDS-opportunistic illness in San Francisco increased from 16 mo in 1994 to 81 mo in 1996. The dramatic improvement in survival that has occurred since the mid-1990s for patients with HIV appears to be greatly attenuated in the sub-group undergoing dialysis. Although this may partly reflect confounding by race, injection drug use and HCV co-infection, future attempts to improve survival among HIV-infected dialysis patients should focus on barriers to the effective use of HAART in this group.

Low socioeconomic status is associated with a higher rate of death in the era of highly active antiretroviral therapy, San Francisco

Highly active antiretroviral therapy (HAART) has dramatically improved survival after AIDS. The benefits of HAART have not been equally realized for all communities, however. We characterize the association of socioeconomic status (SES) with survival after AIDS diagnosis in San Francisco in the period before (1980-1995) and after (1996 - 2001) the wider use of HAART. Using citywide surveillance data, we examined differences in survival after AIDS diagnosis by neighborhood household income using Kaplan-Meier survival analysis and Cox proportional hazards analysis to adjust for significant covariates. Residing in higher SES neighborhoods significantly predicted better survival after AIDS from 1996 to 2001 (hazard ratio = 0.92 per $10,000 increase in neighborhood household income, 95% CI: 0.85-0.99) after adjusting for CD4 count at diagnosis, age, and injection drug user status. Persons living in poorer neighborhoods were less likely to use HAART at any time in the past compared with persons in wealthier neighborhoods. Moreover, no association between survival and neighborhood SES was evident in the era prior to the wide use of HAART. Finally, the difference in survival by neighborhood income level disappeared after controlling for the use of HAART, suggesting that use of or access to treatment explained the association. From 1996 to 2001, survival with AIDS was worse for people living in poorer neighborhoods compared with those living in wealthier neighborhoods of San Francisco as a result of unequal access to or use of HAART.

Review of medical encounters in the 5 years before a diagnosis of HIV-1 infection: implications for early detection

Early detection of HIV infection improves prognosis and reduces transmission, but 30%-40% of cases are diagnosed late. A comprehensive and systematic review of medical encounters before diagnosis has not been done. This study reviews 5 years of medical encounters before the diagnosis of HIV infection in members of a large managed care organization where access to care is reasonably good. Patient characteristics, HIV risk factors, and clinical events preceding diagnosis were examined and tested for association with late diagnosis (CD4 cell count of <200/microL at diagnosis). Of 440 HIV-infected patients, 62% had CD4 cell counts of <350/microL, 43% had CD4 cell counts of <200/microL, and 18% had CD4 cell counts of <50/microL at diagnosis. Twenty-six percent of all patients had risks documented >1 year before diagnosis. Only 22% of patients had one of eight clinical indicators suggested in the literature as reasons to test for HIV >1 year before diagnosis. In multiple logistic regression, older age, male sex, race, risk group, no prior HIV testing, physician-initiated testing, and having any of eight clinical indicators before diagnosis were each associated with late diagnosis (p <or=.05). Late diagnosis remains a challenge despite good access to care. In our setting, effective risk assessment before symptoms arise offers greater potential for raising the mean CD4 cell count at diagnosis than does increased awareness of selected HIV-associated clinical prompts.

Predicting death from HIV/AIDS: a case-control study from Florida public HIV/AIDS clinics

BACKGROUND

After markedly decreasing for 3 years, HIV/AIDS mortality declined only slightly in 1999.

METHODS

The authors conducted a case-control study in four Florida urban public health HIV clinics to evaluate modifiable factors associated with HIV/AIDS mortality in a non-research setting. Structured chart review was conducted for 120 case-patients who died in 1999 and for 240 randomly selected control-patients. Risk factors associated with death in univariate analysis were entered into three conceptually related, matched logistic regression models.

RESULTS

In the final multivariate model, homelessness (adjusted odds ratio [AOR], 9.98; 95% confidence interval [CI], 2.34-42.5), Medicaid insurance (AOR, 3.10; 95% CI, 1.43-6.74), having a documented adherence problem (AOR, 3.50; 95% CI, 1.64-7.47), injection drug use (AOR, 2.46; 95% CI, 1.11-5.43), non-specific liver failure (AOR, 76.9; 95% CI, 6.79-870.9), interrupted highly active antiretroviral therapy (HAART) secondary to side effects (AOR, 4.00; 95% CI, 1.46-10.9), and not receiving HAART (AOR, 2.62; 95% CI, 1.03-6.68) were independent predictors of mortality.

CONCLUSIONS

In addition to medical and clinical indicators, several sociobehavioral-demographic factors remained important throughout the multivariate analysis. Improvement in care should include a focus on social circumstances of infected people. Special attention to the homeless, those with adherence problems, and those with liver disease is clearly indicated.

Induction of mucosal IgA following intravaginal administration of inactivated HIV-1-capturing nanospheres in mice

Concanavalin A-immobilized polystyrene nanospheres (Con A-NS) were developed for the HIV-1 vaccine capable of preventing sexual transmission. Con A-NS could capture efficiently HIV-1 irrespective of their cell tropism (R5 or X4). Furthermore, Con A-NS captured equally infectious and heat-inactivated HIV-1. Inactivated HIV-1-capturing Con A-NS (HIV-NS) were intravaginally administered to mice. Heat-inactivated HIV-1 alone and Con A-NS alone were also administered as control immunogens. Vaginal fluids were collected during and after immunization and analyzed for their anti-HIV-1 antibody levels. Although the anti-HIV-1 IgG antibody was undetectable in any groups, increased anti-HIV-1 IgA antibody response was identified in the vaginal fluids of immunized mice with HIV-NS. The vaginal fluids obtained from the HIV-NS-administered mice showed neutralizing activity against the immunizing HIV-1 strain. A marked difference in vaginal distribution was observed between HIV-NS and other immunogens, and the toxicity of Con A was reduced by conjugation with nanospheres. Thus, HIV-NS may have great potential as a prophylactic HIV-1 vaccine and should be examined further for its efficacy in non-human primates.

Impact of improved treatments on perceptions about HIV and safer sex among inner-city HIV-infected men and women

Protease inhibitor combination therapies have significantly improved the health of many people with HIV/AIDS. Prior studies, consisting mainly of gay men, have indicated that these treatments have prompted reduced concern about HIV and an increase in high-risk behavior. This study assessed the impact of HIV treatment advances on HIV-infected individuals living in inner-city areas. A convenience sample was used (n = 196), consisting largely of heterosexual African-Americans and Hispanics. Almost the entire sample had heard of the latest HIV treatments, and 75% were currently on protease inhibitor regimens. One-third of the sample reported that AIDS was a less serious threat nowadays and that being HIV-positive was not a big deal. Fifteen percent of respondents believed that protease inhibitor combination therapies reduced the risk of HIV transmission, and 10% believed that these treatments reduced need for safer sex practices. As in previous studies of other populations, a significant percentage (23%) of respondents practiced safer sex less often since new HIV treatments arrived. HIV prevention programs need to focus more attention on HIV-infected individuals in inner city areas. Interventions for these individuals need to address changing attitudes and behaviors stemming from HIV treatment advances.

Predictors of use of highly active antiretroviral therapy (HAART) among persons with AIDS in San Francisco, 1996-1999

Highly active antiretroviral therapy (HAART) has contributed to a decrease in AIDS-related morbidity and mortality. This study used population-based AIDS surveillance data to evaluate the prevalence and predictors of HAART use among persons with AIDS in San Francisco. Use of HAART among persons living with AIDS increased from 41% in 1996 to 72% in 1999. Fourteen percent of persons diagnosed with AIDS between 1996 and 1999 initiated HAART before their AIDS diagnosis. Use of HAART before an AIDS diagnosis increased from 5% in 1996 to 26% in 1999. In the multivariable analysis, African Americans, injection drug users, and those without insurance at the time of AIDS diagnosis were less likely to use HAART before AIDS diagnosis. Delayed initiation of HAART after AIDS was more likely to occur among African Americans, injection drug users, homeless persons, those with public insurance, and those with higher CD4 counts. Although the overall prevalence of HAART use was high, disparity in use of HAART existed by race and risk group, patient's insurance status, and facility of diagnosis. Barriers in use of treatment should be identified so all persons with AIDS can benefit from improved therapies.

Cost analysis of erythropoietin versus blood transfusions for cervical cancer patients receiving chemoradiotherapy

PURPOSE

Red blood cell (RBC) transfusions or erythropoietin (EPO) can be used to evade the detrimental effects of anemia during radiotherapy, but the economic consequences of selecting either intervention are not well defined. The RBC transfusion needs during chemoradiotherapy for cervix cancer were quantified to allow comparison of RBC transfusion costs with the projected cost of EPO in this setting.

METHODS AND MATERIALS

For patients receiving pelvic radiotherapy, weekly cisplatin, and brachytherapy, the RBC units transfused during treatment were tallied. RBC transfusion costs per unit included the blood itself, laboratory fees, and expected value (risk multiplied by cost) of transfusion-related viral illness. EPO costs included the drug itself and supplemental RBC transfusions when hemoglobin was not adequately maintained. An EPO dosage based on reported usage in cervix cancer patients was applied.

RESULTS

Transfusions were given for hemoglobin <10 g/dL. Among 12 consecutive patients, 10 needed at least 1 U of RBC before or during treatment, most commonly after the fifth week. A total of 37 U was given during treatment, for an average of 3.1 U/patient. The sum total of the projected average transfusion-related costs was $990, compared with the total projected EPO-related costs of $3869.

CONCLUSIONS

Because no proven clinical advantage has been documented for EPO compared with RBC transfusions to maintain hemoglobin during cervix cancer treatment, for most patients, transfusions are an appropriate and appealingly less expensive option.

Adverse metabolic consequences of HIV protease inhibitor therapy: the search for a central mechanism

Although the clinical introduction of human immunodeficiency virus (HIV) protease inhibitors (PIs) has resulted in a dramatic decline in HIV-related morbidity and mortality, it is now recognized that PI therapy is associated with serious adverse metabolic effects, including peripheral lipoatrophy, increased visceral fat, hyperlipidemia, and insulin resistance. Despite increasing awareness of this metabolic syndrome, the etiology of these side effects remains obscure. This review critically examines current mechanistic hypotheses in the context of the available experimental data. To date, a single unifying explanation for this syndrome has not been confirmed. As data accumulate, it is becoming clear that PIs lack precision in their cellular targets and it is likely that many of the side effects of these drugs are due to inhibition of a number of unrelated molecules.

Expenditures for the care of HIV-infected patients in the era of highly active antiretroviral therapy

BACKGROUND

The introduction of expensive but very effective antiviral medications has led to questions about the effects on the total use of resources for the care of patients with human immunodeficiency virus (HIV) infection. We examined expenditures for the care of HIV-infected patients since the introduction of highly active antiretroviral therapy.

METHODS

We interviewed a random sample of 2864 patients who were representative of all American adults receiving care for HIV infection in early 1996, and followed them for up to 36 months. We estimated the average expenditure per patient per month on the basis of self-reported information about care received.

RESULTS

The mean expenditure was $1,792 per patient per month at base line, but it declined to $1,359 for survivors in 1997, since the increases in pharmaceutical expenditures were smaller than the reductions in hospital costs. Use of highly active antiretroviral therapy was independently associated with a reduction in expenditures. After adjustments for the interview date, clinical status, and deaths, the estimated annual expenditure declined from $20,300 per patient in 1996 to $18,300 in 1998. Expenditures among subgroups of patients varied by a factor of as much as three. Pharmaceutical costs were lowest and hospital costs highest among underserved groups, including blacks, women, and patients without private insurance.

CONCLUSIONS

The total cost of care for adults with HIV infection has declined since the introduction of highly active antiretroviral therapy. Expenditures have increased for medications but have declined for other services. However, there are large variations in expenditures across subgroups of patients.

Reduction in CD8+ cell noncytotoxic anti-HIV activity in individuals receiving highly active antiretroviral therapy during primary infection

Recent advances in the ability to detect people at the early stages of HIV infection now permit the initiation of antiretroviral treatment before the full complement of antiviral immune responses has evolved. However, the influence of early treatment interventions on the developing anti-HIV immune response is unknown. This study investigates the impact of standard highly active antiretroviral therapy (HAART) during the primary stages of HIV infection on the plasma HIV-1 RNA level, CD4(+) and CD8(+) lymphocyte counts, and the CD8(+) cell anti-HIV response. Individuals treated with HAART within 6 months of infection showed dramatic and rapid reductions in HIV-1 RNA levels along with modest increases in CD4(+) cell number and decreases in CD8(+) cell numbers. A significant reduction in the level of CD8(+) cell noncytotoxic suppression of HIV replication was observed over time in most participants receiving HAART. Importantly, those individuals choosing not to receive therapy maintained low but detectable HIV-1 RNA levels and showed no reduction in their CD8(+) cell antiviral response. These results suggest that either continued antigenic challenge is required to sustain CD8(+) cell-mediated anti-HIV activity, or that HAART has some inhibitory effect on this important immunologic function during the early stages of infection.

Reduction in CD8+ cell noncytotoxic anti-HIV activity in individuals receiving highly active antiretroviral therapy during primary infection

Recent advances in the ability to detect people at the early stages of HIV infection now permit the initiation of antiretroviral treatment before the full complement of antiviral immune responses has evolved. However, the influence of early treatment interventions on the developing anti-HIV immune response is unknown. This study investigates the impact of standard highly active antiretroviral therapy (HAART) during the primary stages of HIV infection on the plasma HIV-1 RNA level, CD4(+) and CD8(+) lymphocyte counts, and the CD8(+) cell anti-HIV response. Individuals treated with HAART within 6 months of infection showed dramatic and rapid reductions in HIV-1 RNA levels along with modest increases in CD4(+) cell number and decreases in CD8(+) cell numbers. A significant reduction in the level of CD8(+) cell noncytotoxic suppression of HIV replication was observed over time in most participants receiving HAART. Importantly, those individuals choosing not to receive therapy maintained low but detectable HIV-1 RNA levels and showed no reduction in their CD8(+) cell antiviral response. These results suggest that either continued antigenic challenge is required to sustain CD8(+) cell-mediated anti-HIV activity, or that HAART has some inhibitory effect on this important immunologic function during the early stages of infection.