Acute HIV syndrome after discontinuation of antiretroviral therapy in a patient treated before seroconversion

Clinical Characteristics of Retroviral Rebound Syndrome: A Case Report and Literature Review

We herein report a case of retroviral rebound syndrome (RRS) complicated with hemophagocytic lymphohistiocytosis. Owing to the paucity of comprehensive data on RRS, we also conducted a literature review. All 19 cases included in the review presented within 2 months after the discontinuation of antiretroviral therapy. They were usually accompanied by both a significant decrease in CD4 count (median 292/μL) and a rapid increase in plasma human immunodeficiency virus loads (median 3.5×10⁵/mL). Although life-threatening complications were reported, the overall prognosis was favorable. The outcomes of this review aided in the diagnosis of the present case.

FRET-Based Detection and Quantification of HIV-1 Virion Maturation

HIV-1 infectivity is achieved through virion maturation. Virus particles undergo structural changes via cleavage of the Gag polyprotein mediated by the viral protease, causing the transition from an uninfectious to an infectious status. The majority of proviruses in people living with HIV-1 treated with combination antiretroviral therapy are defective with large internal deletions. Defective proviral DNA frequently preserves intact sequences capable of expressing viral structural proteins to form virus-like particles whose maturation status is an important factor for chronic antigen-mediated immune stimulation and inflammation. Thus, novel methods to study the maturation capability of defective virus particles are needed to characterize their immunogenicity. To build a quantitative tool to study virion maturation in vitro, we developed a novel single virion visualization technique based on fluorescence resonance energy transfer (FRET). We inserted an optimized intramolecular CFP-YPF FRET donor-acceptor pair bridged with an HIV-1 protease cleavage sequence between the Gag MA-CA domains. This system allowed us to microscopically distinguish mature and immature virions via their FRET signal when the FRET donor and acceptor proteins were separated by the viral protease during maturation. We found that approximately 80% of the FRET labeled virus particles were mature with equivalent infectivity to wild type. The proportion of immature virions was increased by treatment of virus producer cells with a protease inhibitor in a dose-dependent manner, which corresponded to a relative decrease in infectivity. Potential areas of application for this tool are assessing maturation efficiency in different cell type settings of intact or deficient proviral DNA integrated cells. We believe that this FRET-based single-virion imaging platform will facilitate estimating the impact on the immune system of both extracellular intact and defective viruses by quantifying the Gag maturation status.

Intracranial hypertension and papilloedema as a complication to low antiretroviral therapy adherence in a man living with chronic HIV

We describe a 61-year-old man living with HIV on antiretroviral therapy (ART), who presented with headache, dizziness and blurred vision. Latest CD4⁺ cell count 3 months prior to admission was 570×10⁶ cells/mL and HIV viral load <20 copies/mL. The patient was diagnosed with cerebrospinal fluid (CSF) lymphocytic pleocytosis, raised intracranial pressure and papilloedema. Neuroimaging showed normal ventricular volume and no mass lesions, suggesting (1) neuroinfection (2) idiopathic intracranial hypertension or (3) retroviral rebound syndrome (RRS) as possible causes. Neuroinfection was ruled out and idiopathic intracranial hypertension seemed unlikely. Elevated plasma HIV RNA level was detected consistent with reduced ART adherence prior to admission. RRS is a virological rebound after ART interruption, which can mimic the acute retroviral syndrome of acute primary infection. To the best of our knowledge, we describe the second case of RRS presenting as CSF lymphocytic pleocytosis and elevated intracranial pressure after low ART adherence.

HIV-1 variants are archived throughout infection and persist in the reservoir

The HIV-1 reservoir consists of latently infected cells that persist despite antiretroviral therapy (ART). Elucidating the proviral genetic composition of the reservoir, particularly in the context of pre-therapy viral diversity, is therefore important to understanding reservoir formation and the persistence of latently infected cells. Here we investigate reservoir proviral variants from 13 Zambian acutely-infected individuals with additional pre-therapy sampling for a unique comparison to the ART-naïve quasispecies. We identified complete transmitted/founder (TF) viruses from seroconversion plasma samples, and additionally amplified and sequenced HIV-1 from plasma obtained one year post-infection and just prior to ART initiation. While the majority of proviral variants in the reservoir were most closely related to viral variants from the latest pre-therapy time point, we also identified reservoir proviral variants dating to or near the time of infection, and to intermediate time points between infection and treatment initiation. Reservoir proviral variants differing by five or fewer nucleotide changes from the TF virus persisted during treatment in five individuals, including proviral variants that exactly matched the TF in two individuals, one of whom had remained ART-naïve for more than six years. Proviral variants during treatment were significantly less divergent from the TF virus than plasma variants present at the last ART-naïve time point. These findings indicate that reservoir proviral variants are archived throughout infection, recapitulating much of the viral diversity that arises throughout untreated HIV-1 infection, and strategies to target and reduce the reservoir must therefore permit for the clearance of proviruses encompassing this extensive diversity.

Despite reducing viremia to levels below the limit of detection in standard assays, effective antiretroviral therapy (ART) does not eradicate cells latently infected with HIV-1. These cells serve as a reservoir for viral rebound if therapy is interrupted; thus, understanding the composition of the reservoir may yield further targets for HIV-1 cure strategies. We have taken a genetic approach to elucidating the reservoir in 13 Zambian subtype C seroconvertors who were followed longitudinally through ART initiation and virologic suppression. In five of the 13 individuals, provirus sequences identical to or differing by five or fewer nucleotides from the transmitted/founder virus were detected, indicating archiving and persistence of early infection variants for more than six years following infection. While the majority of proviral variants in latently infected cells were most closely related to plasma virus circulating immediately prior to treatment initiation, additional variants dating to intermediate time points in the infection were also observed. These findings demonstrate that virus is archived during all stages of ART-naïve infection, and these variants persist throughout ART. HIV-1 cure strategies to eliminate the reservoir must address the broad genetic diversity of a within-host proviral quasispecies including variants archived from acute through chronic infection.

Acute Human Immunodeficiency Virus (HIV) Syndrome After Nonadherence to Antiretroviral Therapy in a Patient With Chronic HIV Infection: A Case Report

We report a rare case of acute human immunodeficiency virus (HIV) syndrome in a patient with chronic HIV infection with acute illness indistinguishable from acute retroviral syndrome. The patient presented with an acute febrile mononucleosis-like illness after increasing nonadherence to antiretroviral therapy. A marked increase in HIV RNA level of 1 220 000 copies/mL from less than 20 copies/mL occurred within 3 weeks. The diagnosis of acute HIV syndrome was made after alternative causes of illness were ruled out.

Short-term antiretroviral therapy to prevent mother-to-child transmission is safe and results in a sustained increase in CD4 T-cell counts in HIV-1-infected mothers

BACKGROUND

Short-term antiretroviral therapy (START) to prevent mother-to-child transmission (MTCT) is currently recommended for all HIV-1-infected pregnant women. The objective of this study was to assess the effect on CD4 cell counts and viral load dynamics the withdrawal of START after birth could generate.

METHODS

This was a 5-year cohort study involving HIV-1-infected pregnant women who presented with CD4 counts >300 cells/microL and had received START to prevent MTCT.

RESULTS

Seventy-five pregnancies were assessed. In 24 cases, there was a history of antiretroviral therapy prior to prophylaxis. The median baseline CD4 count was 573 cells/microL. In 75% of cases, prophylaxis was started after 26.6 weeks of gestation. The median CD4 cell count increase over baseline during prophylaxis was 24.5%. In only five cases did HIV-1 viral load remain detectable during prophylaxis. After START, CD4 cell counts did not drop significantly, and the HIV-1 viral load plateau was near the baseline level. The estimated mean time for CD4 count to fall below 300 cells/microL was 3.5 years and was directly associated with high baseline CD4 cell count, as well as with CD4 increase after prophylaxis, whereas it was negatively correlated with previous use of antiretroviral (ARV) drugs and persistence of detectable HIV-1 viral load during prophylaxis.

CONCLUSIONS

A potent, well-tolerated prophylactic ARV regimen can improve CD4 cell counts during and after START. In women receiving such prophylaxis, there is a remarkable time interval for CD4 cell counts to drop to levels that indicate treatment.

Evaluation of antiretrovirals in animal models of HIV infection

Animal models of HIV infection have played an important role in the development of antiretroviral drugs. Although each animal model has its limitations and never completely mimics HIV infection of humans, a carefully designed study allows experimental approaches that are not feasible in humans, but that can help to better understand disease pathogenesis and to provide proof-of-concept of novel intervention strategies. While rodent and feline models are useful for initial screening, further testing is best done in non-human primate models, such as simian immunodeficiency virus (SIV) infection of macaques, because they share more similarities with HIV infection of humans. In the early years of the HIV pandemic, non-human primate models played a relatively minor role in the antiretroviral drug development process. Since then, a better understanding of the disease and the development of better drugs and assays to monitor antiviral efficacy have increased the usefulness of the animal models. In particular, non-human primate models have provided proof-of-concept for (i) the benefits of chemoprophylaxis and early treatment, (ii) the preclinical efficacy of novel drugs such as tenofovir, (iii) the virulence and clinical significance of drug-resistant viral mutants, and (iv) the role of antiviral immune responses during drug therapy. Ongoing comparison of results obtained in animal models with those observed in human studies will further validate and improve these animal models so they can continue to help advance our scientific knowledge and to guide clinical trials. This article forms part of a special issue of Antiviral Research marking the 25th anniversary of antiretroviral drug discovery and development, Vol 85, issue 1, 2010.

Retroviral rebound syndrome after treatment discontinuation in a 15 year old girl with HIV attracted through mother-to-child transmission: case report

A case of a 15 year old girl with retroviral rebound syndrome after discontinuation of highly active antiretroviral treatment (HAART) due to side effects is presented. The patient was transmitted with HIV at birth by her mother. She had recovered from severe AIDS after HAART was initiated five years earlier. This is the first case reported in the literature of retroviral rebound syndrome in a vertically transmitted HIV-infected patient.

Multiple organ failure during primary HIV infection

The appearance of primary HIV infection ranges from an asymptomatic presentation to a symptomatic illness resembling infectious mononucleosis. Severe unusual presentations include acute myopericarditis, renal failure, and opportunistic infections such as esophageal candidiasis, cytomegalovirus infection, and Pneumocystis jirovecii pneumonia. We report a case of multiple organ failure during primary HIV infection.

Cellular immunotherapy for cytomegalovirus and HIV-1 infection

Current antiviral drugs do not fully reconstitute the specific antiviral immune control in chronically human immunodeficiency virus (HIV)-1-infected patients or in cytomegalovirus (CMV)-infected patients after hematopoietic stem cell transplantation. Therefore, immunotherapy in which the patient's immune system is manipulated to enhance antiviral immune responses has become a promising area of viral immunology research. In this review, an overview is provided on the cellular immunotherapy strategies that have been developed for HIV infection and CMV reactivation in immunocompromised patients. As an introduction, the mechanisms behind the cellular immune system and their importance for the development of a workable immunotherapy approach are discussed. Next, the focus is shifted to the immunopathogenesis of CMV and HIV-1 infections to correlate these findings with the concepts and ideas behind the viral-specific immunotherapies discussed. Current and future perspectives of active and passive cellular immunotherapy for the treatment of CMV and HIV-1 infections are reviewed. Finally, pitfalls and key issues with regard to the development of immunotherapy protocols that can be applied in a clinical setting are addressed.

The development and utility of a clinical algorithm to predict early HIV-1 infection

The association between self-reported clinical factors and recent HIV-1 seroconversion was evaluated in a prospective cohort of 4652 high-risk participants in the HIV Network for Prevention Trials (HIVNET) Vaccine Preparedness Study. Eighty-six individuals seroconverted, with an overall annual seroconversion rate of 1.3 per 100 person-years. Four self-reported clinical factors were significantly associated with HIV-1 seroconversion in multivariate analyses: recent history of chlamydia infection or gonorrhea, recent fever or night sweats, belief of recent HIV exposure, and recent illness lasting > or =3 days. Two scoring systems, based on the presence of either 4 or 11 clinical factors, were developed. Sensitivity ranged from 2.3% (with a positive predictive value of 12.5%) to 72.1% (with a positive predictive value of 1%). Seroconversion rates were directly associated with the number of these clinical factors. The use of scoring systems comprised of clinical factors may aid in detecting early and acute HIV-1 infection in vaccine and microbicide trials. Organizers can educate high-risk trial participants to return for testing during interim visits if they develop these clinical factors. Studying individuals during early and acute HIV-1 infection would allow scientists to investigate the impact of the intervention being studied on early transmission or pathogenesis of HIV-1 infection.

Retroviral Rebound Syndrome with Fatal Outcome after Discontinuation of Antiretroviral Therapy

We report the case of a patient with AIDS who developed retroviral rebound syndrome that led to death after antiretroviral therapy was stopped because of toxicity. Cases of retroviral rebound syndrome reported in the literature are briefly reviewed.

Primary human immunodeficiency virus type 1 infection

Primary human immunodeficiency virus type 1 (HIV-1) infection represents the initial stage of disease that immediately follows viral entry into the body. Primary infection is frequently accompanied by an acute retroviral syndrome with associated high levels of plasma HIV-1 RNA and the development of host immune responses. The identification of subjects during this period requires a high index of suspicion and an understanding of how to make the diagnosis, as standard HIV-1 antibody tests can initially be negative. Identifying these people provides a unique opportunity for early counseling to reduce further transmission, facilitates entry into care, and allows for further study of the immunopathogenesis of disease and the potential role of early antiretroviral therapy.

Discontinuation of antiretroviral therapy in patients with chronic HIV infection: clinical, virologic, and immunologic consequences

To investigate the clinical, virologic and immunologic consequences of planned treatment interruptions in chronically HIV-infected patients. One hundred forty-one patients with undetectable viral load for at least 6 months and CD4+ T cells count greater than 500 per microliter were recruited. Their antiretroviral therapy was stopped and clinical, analytic, virologic, and immunologic data were recorded at baseline, during discontinuation, and after restarting treatment. Viral load rebound after discontinuation in 137 (97%) patients, and was similar to prehighly active antiretroviral therapy (HAART) levels. A rapid decrease in CD4+ T-cell count (median, 240 cells per microliter), was observed in the first 3 months in all patients, with pronounced differences between them. After a median follow-up of 36 months, 45.5% patients were still without therapy. Factors related to a more severe decline were a prior lower CD4+ T nadir (<200 cells per microliter) before starting HAART, a greater increase (>500 cells per microliter) with it, a higher CD4+ T-cell count before interruption (>800 cells per microliter) and a higher viral load rebound after it. The increase in CD4+ T-cell counts after reinitiation was slower than the decline and only 55% of patients have regained the preinterruption levels at 12 months of follow- up. Twelve infectious events were registered. Treatment failure related to drug resistance was observed in two patients. Planned treatment interruptions may be safe in selected patients with previous CD4+ T cell nadir greater than 200 cells per microliter and pre-HAART VL less than 55.000 copies per milliliter, but should be not recommended in patients with the prognostic factors related to a rapid decline described in this study. Furthermore, there is a considerable concern about the development of drug resistance and the possibility of an incomplete immune reconstitution after the treatment interruption in some patients.

Primary HIV-1 infection: Diagnosis, pathogenesis, and treatment

Primary HIV-1 infection represents the time when the virus is first disseminating throughout the body and induces host immune responses. Diagnosing this stage of disease requires an understanding of who is at risk, the clinical manifestations of primary infection, and how the diagnosis is made. Identifying these individuals allows for counseling to prevent further transmission to others and the potential benefits associated with early antiretroviral therapy. Moreover, studying these individuals provides important insight into the biology of HIV-1 transmission and immunopathogenesis.

Strategies to Decrease Viral Load Rebound, and Prevent Loss of Cd4 and Onset of Resistance during Structured Treatment Interruptions

Background

Toxicity and other drug adherence-related factors have contributed to decreased compliance to antiretroviral regimens amongst HIV-infected patients. Irregular therapy disruption causes loss of CD4 T cells, onset of drug resistance and rapid rebound of plasma viral load (VL). However, an appropriate choice of drugs and properly scheduled structured treatment interruptions (STIs) may limit VL rebound, maintain CD4 counts and minimize resistance.

Methods

We conducted a clinical study of STIs, RIGHT 901, involving 60 drug-naive patients with chronic HIV infection (CD4 >300, VL >10000) randomized to receive didanosine-stavudine-indinavir (IDV group) or didanosine-stavudine-hydroxyurea (HU group), for 12 weeks. Subsequently, all patients were randomized again to start STI (short induction) or to continue the therapy for an additional 24 weeks before starting STI (long induction). Both groups underwent four STI cycles and then stopped therapy as long as viraemia remained below 10000 copies/ml before reinitiating another four cycles of STI.

Results

During continuous therapy VLs were suppressed at similar rates in both the HU and IDV groups, while a blunted CD4 count was documented in the HU group. Following the first stop median VL rebounded close to baseline values in both groups, however, during the following STI median VL rebound decreased in the HU group, while in the IDV group VL continued to rebound to values close to baseline, and the difference between the two groups was statistically significant. Moreover, patients treated with HU had a constant and stable CD4 increase during STI, whereas CD4 counts fluctuated in the IDV group, with sharp falls during treatment interruptions and partial CD4 recovery following treatment restart. Even in the presence of IDV resistance predisposing mutations at baseline, no genotypic change in the protease sequence was observed during STI. A relevant mutation in the reverse transcriptase sequence (K70R) emerged in one patient interrupting treatment after 36 weeks of continuous therapy and in one patient after four STI cycles. Side effects (no major events) were similar among groups.

Conclusions

An appropriate choice of STI schedule and regimens containing drugs less prone to resistance and/or able to prevent CD4 fluctuation may contribute to optimizing STI for chronically infected patients with respect to limiting viral rebound, improving CD4 counts and maintaining a resistance profile comparable to continuous highly active antiretroviral therapy.

Can structured treatment interruptions (STIs) be used as a strategy to decrease total drug requirements and toxicity in HIV infection?

Structured treatment interruptions (STIs) are a new strategy under investigation in clinical trials involving a number of different HIV-infected populations. These populations include patients with prolonged HIV RNA suppression who were treated in either seroconversion or later in disease, and patients with virologic failure despite HAART, prior to the initiation of a salvage regimen. The goals of STI vary in each of these groups. Until the results of clinical trials are available, the use of STIs must be considered experimental. There are a number of potential risks, including the loss of a significant number of CD4 cells with the development of opportunistic infections, rebound of HIV RNA, emergence of drug resistance, and reseeding of viral reservoirs. However, STIs also hold the promise for decreasing antiretroviral drug burden and toxicity, and improving quality of life. Given that much of the world's population infected with HIV does not have access to continuous HAART, the development of strategies that could decrease overall drug burden and cost is important. This paper provides an update of the recently published and presented studies on the use of STIs in various populations of HIV-infected patients. In particular, it discusses what is known and unknown about the relative risks and benefits of this approach, and what studies are ongoing. Lastly, it identifies how the use of STIs could decrease drug burden and toxicity in patients receiving therapy.

Antiretroviral drug resistance testing in adults infected with human immunodeficiency virus type 1: 2003 recommendations of an International AIDS Society-USA Panel

New information about the benefits and limitations of testing for resistance to human immunodeficiency virus (HIV) type 1 (HIV-1) drugs has emerged. The International AIDS Society-USA convened a panel of physicians and scientists with expertise in antiretroviral drug management, HIV-1 drug resistance, and patient care to provide updated recommendations for HIV-1 resistance testing. Published data and presentations at scientific conferences, as well as strength of the evidence, were considered. Properly used resistance testing can improve virological outcome among HIV-infected individuals. Resistance testing is recommended in cases of acute or recent HIV infection, for certain patients who have been infected as long as 2 years or more prior to initiating therapy, in cases of antiretroviral failure, and during pregnancy. Limitations of resistance testing remain, and more study is needed to refine optimal use and interpretation.

Greater reversal of CD4+ cell abnormalities and viral load reduction after initiation of antiretroviral therapy with zidovudine, lamivudine, and nelfinavir before complete HIV type 1 seroconversion

In a prospective open-label study, 41 male subjects received nelfinavir, zidovudine, and lamivudine stratified as either: early stage (ES; negative/indeterminate Western blot; n = 19) or late stage (LS; positive Western blot; n = 22) primary HIV-1 infection. Despite higher median baseline HIV-1 RNA levels and lower CD4(+) cell numbers in the ES subjects, a significantly greater decline in viral load (-3.46 vs. -2.83 log(10) copies/ml; p = 0.023) and increase in CD4(+) cell number (+85 vs. +41 cells/month increase, p = 0.01) were observed over the first 3 months of therapy such that both groups had comparable results at 1 year. The proportion with HIV-1 RNA < 50 copies/mL at 1 year was similar (9 of 19 ES subjects and 11 of 22 LS subjects by intention-to-treat analysis). Memory CD4(+) cell numbers, and activated CD4(+) percentages, were also significantly improved in ES subjects. Despite poorer prognostic markers at baseline ES subjects achieved responses similar to those of LS subjects after 1 year of treatment.

Structured treatment interruption in patients infected with HIV: a new approach to therapy

Current antiretroviral regimens are limited by issues of potency, adherence, toxicity, resistance and cost. With these limitations and the realisation that eradication of HIV infection currently is not possible, there is enthusiasm for strategies that allow discontinuation of medications, such as the structured treatment interruption (STI). STI is hypothesised to have benefits in three distinct clinical scenarios: acute treated infection, chronic treated infection with controlled viraemia, and chronic treated infection without controlled viraemia (salvage therapy). In patients with acute treated HIV infection, STI may preserve or enhance cellular immune responses to allow continued virological suppression in the absence of ongoing treatment. The Berlin patient presented with acute HIV infection prior to seroconversion and received antiretroviral therapy. After two treatment interruptions (for intercurrent infections), he permanently discontinued therapy and remained virologically suppressed for 2 years. Investigators from Massachusetts General Hospital described eight patients with acute or early HIV infection who received treatment and then underwent one or two STI. After the STIs, five of eight patients showed enhanced cellular immune responses and continued with virological suppression off treatment for a median of 2.7 years. In patients with chronic treated infection with controlled viraemia, STI may enhance immune responses as in the case of acute infection, or may allow decreased drug exposure and toxicity. Investigators from the National Institutes of Health enrolled 18 patients with chronic HIV infection and virological suppression while taking antiretroviral regimens. With a single STI, all patients rebounded, although one (6%) ultimately continued off therapy with virological suppression. The largest study of STI is the Spanish Swiss Intermittent Treatment Trial in which 128 patients with chronic suppressed HIV infection on antiretroviral therapy underwent four cycles of STI. At 52 weeks, 17% had suppressed viral load levels of <5000 copies/ml in the absence of therapy. In patients with chronic treated infection without controlled viraemia (salvage therapy), STI promotes a shift from resistant to wild-type (i.e. no mutations) virus. In the Hamburg cohort, the shift to wild-type virus was seen in 28 of 45 heavily treatment-experienced patients after an STI. Seventy-two percent of these patients experienced a virological response on a subsequent regimen, although many ultimately experienced virological rebound. In the San Francisco cohort, a shift to wild-type virus was seen in 15 of 17 protease inhibitor-experienced patients and six of these patients achieved virological suppression to <200 copies/ml on a new regimen. Risks associated with STI include increases in viral load levels with the risk of loss of virological control (i.e. failure to resuppress on therapy), repopulation of viral reservoirs and antiretroviral resistance, and decreases in CD4+ cell counts with the risk of loss or dysregulation of immune function and the occurrence of clinical events. Other risks include acute retroviral syndrome and the recurrence of short-term adverse effects. Currently, STI cannot be recommended as part of routine clinical care. Prospective studies are needed to assess the risks and benefits of this strategy in all clinical settings.

Structured treatment interruptions in HIV/AIDS therapy

Structured treatment interruption (STI) has been investigated for three distinct clinical scenarios: during acute infection with the goal of immune reconstitution and auto immunization; during chronic infection, to decrease the amount and toxicity of antiretroviral drugs; and during virologic failure to restore response to subsequent antiretroviral therapy. The potential costs and benefits of STI should be determined.

The failure of HAART to cure the HIV-1/AIDS complex. Suggestions to add integrase inhibitors as complementary virostatics, and to replace their continuous long combination applications by short sequences differing by drug rotations

While the intensive virostatic combinations applied according to the conventional models (such as HAART), based only on the attacks of two HIV-1 targets, retrotranscriptase and protease, and applied in a long and continuous fashion, a) are notably toxic, b) do not correct completely the abnormal immunologic parameters, and c) are followed by particularly severe and poorly sensitive relapses in case of discontinuation, we propose to the 'AIDS treatment headquarters' to include in their failing strategy the two original features which we have included in the treatment of a cohort of a dozen patients, treatment applied at all but one AIDS stage. We attack one more HIV-1 target than the conventional protocols do, by adding inhibitors of integrase; we apply the combinations of virostatics, comprising inhibitors of the three targets, in short sequences (of 3 weeks), between which the analogues are changed inside each series. The first patient of the cohort started his treatment 8.5 years ago, and the entries of the others into it have been at random and not randomized. All patients are alive today and in excellent condition.

Pseudo-Primary Infection Syndrome following Discontinuation of Antiretroviral Therapy

We report the case of a retroviral rebound syndrome associated with parotid gland enlargement in a chronically HIV-infected man.

Natural history of HIV-1 infection

Infection with the human immunodeficiency virus type 1 (HIV-1) results in progressive loss of immune function marked by depletion of the CD4+ T-lymphocytes, leading to opportunistic infections and malignancies characteristic of AIDS. Although both host and viral determinants influence the rate of disease progression, the median time from initial infection to the development of AIDS among untreated patients ranges from 8 to 10 years. The clinical staging of HIV disease and the relative risk of developing opportunistic infections historically relied on the CD4+ T-lymphocyte counts. Although more recent studies have shown the importance of viral load quantitation in determining the rate of disease progression, it is still useful to categorize HIV disease stage on the basis of the degree of immunodeficiency: early disease (CD4+ > 500 cells/mL), mid-stage disease (CD4+ between 200 and 500 cells/mL), and end-stage disease (CD4+ < 50 cell/mL). This article reviews the natural history of HIV disease at each stage of HIV-1 infection with emphasis on acute infection and the major virologic and immunologic determinants of disease progression.

Primary HIV infection. Current trends in transmission, testing, and treatment

In the changing kaleidoscope of HIV disease, early detection of primary infection has become increasingly important. Primary care physicians who recognize the signs and symptoms are in an ideal position to diagnose the disease at an early stage and to help stem the tide of new infections in the community. In this article, Drs Yu and Daar discuss current strategies for early diagnosis, including recommended testing and steps to prevent transmission of the virus, and present the latest thinking about antiretroviral therapy during primary HIV infection.

Antiretroviral therapy during primary immunodeficiency virus infection can induce persistent suppression of virus load and protection from heterologous challenge in rhesus macaques

A limited period of chemotherapy during primary immunodeficiency virus infection might provide a long-term clinical benefit even if treatment is initiated at a time point when virus is already detectable in plasma. To evaluate this strategy, we infected rhesus macaques with the pathogenic simian/human immunodeficiency virus RT-SHIV and treated them with the antiretroviral drug (R)-9-(2-phosphonylmethoxypropyl)adenine (PMPA) for 8 weeks starting 7 or 14 days postinfection. PMPA treatment suppressed viral replication efficiently in all of the monkeys. After chemotherapy ended, virus replication rebounded and viral RNA in plasma reached levels comparable to that of the controls in four of the six monkeys. However, in the other two animals, virus loads peaked only moderately after withdrawal of the drug and then declined to low or even undetectable levels. These low levels of viremia remained stable for at least 31 weeks after cessation of therapy. At this time point, these two monkeys were challenged with SIV(8980) to evaluate whether the host responses which were able to keep RT-SHIV replication under control were also sufficient to protect against infection with a highly pathogenic heterologous virus. Both monkeys proved to be protected against the heterologous virus. In one of the two animals, low levels of SIV(8980) replication were detected. Thus, by chemotherapy during the acute phase of pathogenic virus replication, we could achieve not only persistent virus load suppression in two out of six monkeys but also protection from subsequent heterologous challenge. By this chemotherapeutic attenuation, the replication kinetics of attenuated viruses could be mimicked and a vaccination effect similar to that induced by live attenuated simian immunodeficiency virus vaccines was achieved.

Human anti-HIV-1 tat sFv intrabodies for gene therapy of advanced HIV-1-infection and AIDS

The early successes of highly active anti-retroviral therapies (HAART) for the treatment of HIV-1-infection and AIDS have raised the question as to whether there is a legitimate role for gene therapy in the treatment of this chronic infectious disease. However, in many patients the profound suppression of viral replication is short lived, particularly if patients have been treated with sequential monotherapies in the past, have been infected with a highly drug resistant isolate of HIV-1, or have temporarily discontinued therapy as a "holiday" or because of drug intolerance. In addition, life-long adherence to maintenance HAART will probably be required even in responding patients with undetectable viremia because of the reservoirs of latently infected cells that can persist for years. Gene therapy through the introduction of anti-retroviral "resistance" genes into CD4(+) T cells is one approach that could give long term protection to these HIV-1 susceptible cells in vivo. We have explored this approach by developing intrabodies to the critical HIV-1 transactivator protein, Tat that is absolutely required for HIV-1 replication. This provocative treatment approach, that will be tested in a clinical gene therapy trial, sets the groundwork for determining if anti-Tat intrabody gene therapy together with HAART can provide a treatment strategy for the immune reconstitution of HIV-1-infected patients with advanced disease.

Dynamics of viral load rebound and immunological changes after stopping effective antiretroviral therapy

BACKGROUND

This study addresses the dynamic of viral load rebound and immune system changes in a cohort of eight consecutive HIV-1-infected patients in very early stages [all the patients were taking highly active antiretroviral therapy (HAART} and were recruited in the coordinating center from a larger study] who decided to discontinue HAART after 1 year of treatment and effective virologic response. The safety of this procedure and the outcome with reintroduction of the same treatment was also investigated.

METHODS

Plasma, cerebrospinal fluid (CSF), and lymphatic tissue viral loads were measured at baseline; lymphocyte immunophenotyping and CD4 lymphocyte proliferative responses to mitogens and specific antigens were assessed. The same antiretroviral therapy was reintroduced as soon as plasma viral load became detectable (above 200 copies/ml).

RESULTS

At day 0, plasma viral load was below 20 copies/ml in all eight patients (and below 5 copies/ml in five of eight patients). A rebound in plasma viral load was detected in all patients from day 3 to day 31 with a mean doubling time of 2.01 (SE 0.29) days. Three out of eight patients achieved a peak plasma viral load at least 0.5 log10 above baseline, pretreatment values. Mutations associated with resistance to reverse transcriptase or protease inhibitors were not detected. After 31 days off therapy, CD4 lymphocytes decreased [mean 45% (SE 4) to 37% (SE 3); P = 0.04], CD8+CD28+ lymphocytes decreased [mean 59% (SE 5) to 43% (SE 4); P = 0.03], and CD8+CD38+ lymphocytes increased [mean 55% (SE 3) to 66% (SE 4); P = 0.009]. Mean stimulation indices of lymphocytes treated with phytohemagglutinin (PHA) and CD3 decreased from day 0 to day 31 from 34% (SE 8) to 17% (SE 9) (P = 0.06) and from 24% (SE 8) to 5% (SE 2) (P = 0.02), respectively. These changes were mainly contributed by the group of five patients with plasma viral load below 5 copies/ml at day 0. Viral load dropped below 20 copies/ml in all patients after 1 month of restarting the same antiretroviral regimen.

CONCLUSIONS

Discontinuation of HAART after 1 year of successful treatment is followed by a rapid rebound of viral load; this rapidly returns to undetectable levels following reintroduction of the same treatment. In patients with more effective control of virus replication (viremia below 5 copise/ml), discontinuation of treatment was associated with more severe impairment of immunologic parameters.

Failure to learn human immunodeficiency virus test results in Los Angeles public sexually transmitted disease clinics

BACKGROUND

Early human immunodeficiency virus (HIV) defection is essential for initiating treatment and partner-notification activities. Sexually transmitted disease (STD) clinic attendees are at high risk for infection and should be made aware of their HIV status.

GOAL

To determine the characteristics associated with not receiving an HIV test result in an STD clinic setting.

STUDY DESIGN

Confidential HIV testing was offered to 6,705 persons attending four public STD clinics in Los Angeles who submitted blood for syphilis serology and were tested for HIV antibody in an unlinked HIV serosurvey. Human immunodeficiency virus test results and return status were anonymously linked to other risk information.

RESULTS

Only one-third of attendees were tested and given their results. Those testing HIV positive in the anonymous survey and those requesting HIV testing were most likely to receive a test result (i.e., 41% and 49%, respectively). Those solely requesting an STD examination, repeat testers, and African-Americans were least likely to receive a result (i.e., 32%, 30%, and 26%, respectively).

CONCLUSIONS

Most STD clinic patients fail to receive an HIV test result. Other strategies, such as rapid HIV testing, are needed to increase participation and receipt of HIV test results in this high-risk population.