Pathogenesis of infection with human immunodeficiency virus

Lymphoid interstitial pneumonitis in a newly diagnosed late presenter of human immunodeficiency virus infection: a case report

Background

An increase has been described throughout the years in the frequency of various uncommon diseases in people living with human immunodeficiency virus (HIV). Particularly late presenters are associated with a significant risk not only for acquired immune deficiency syndrome (AIDS)-defining conditions but also for non AIDS-defining diseases which aggravate the prognosis of patients. Lymphoid interstitial pneumonitis (LIP) is one of these conditions described more often after the onset of HIV epidemic. LIP is a benign polyclonal lymphoproliferative disorder of the lung with not well characterized clinical and radiographic findings.

Case presentation

We report the diagnostic approach and clinical progress of a newly diagnosed late presenter of HIV infection with respiratory problems in our HIV unit. The findings of computed tomography indicated the diagnosis of HIV-associated LIP, although this condition is mainly described in a normal range of CD4 cell count.

Conclusion

This case presentation highlights the importance of timely diagnosis and initiation of antiretroviral therapy. The increase of CD4 cell count and viral suppression may improve the symptoms of LIP.

Changing the pill: developments toward the promise of an ultra-long-acting gastroretentive dosage form

INTRODUCTION

The development of oral sustained release dosage forms has been a longstanding goal due to the potential for ease of administration, improved pharmacokinetics, reduced dosing frequency, and improved adherence. The benefits of multiday single-dose drug delivery are evident in the success and patient adoption of injected and implanted dosage forms. However, in the space of oral medications, all current commercially available gastric resident dosage forms, and most in development, are limited to gastric residence of less than 1 day.

AREAS COVERED

Reviews of systems to extend gastric residence reveal that 1 day or more residence has been an unmet challenge. New dosage forms are in development that seek to address many of the key physiological and design challenges of long-term gastric retention beyond 24 h  and up to a week or longer. The present analysis highlights the design, material considerations and implications of unfolding dosage form systems with ultra-long-term gastric residence.

EXPERT OPINION

The development of oral dosage forms providing sustained release of high potency medications over days or weeks could transform care, significantly decrease patient burden in chronic disease management and improve outcomes.

Alcohol Abuse and Stage of HIV Disease in Intravenous Drug Abusers

Our objective was to identify factors that might correlate with human immunodeficiency virus (HIV) disease stage in intravenous drug abusers (IVDA). Particular attention was given to alcohol abuse. We accordingly explored in a cross-sectional study the relation between stage of HIV disease and age, sex, needle sharing, ethnicity, self-reported history of alcohol consumption and CAGE scores. IVDA from a single municipal hospital were subdivided into three groups according to HIV disease status. Group 1 comprised 42 individuals with AIDS; group 2 comprised 114 who were HIV positive but without AIDS; and group 3 comprised 52 who were HIV negative. Information on alcohol consumption and CAGE responses were obtained by questionnaire and interview.

Discriminant analysis indicated that alcohol abuse, assessed either by self-reported consumption or by CAGE scores, was significantly more common in the AIDS group than in either the HIV positive or the HIV negative groups, when controlled for age, sex, and needle sharing status. The relative risk of AIDS was 3.8 times higher in the heavy drinkers than in moderate drinkers. Needle sharing was also more common in the AIDS group than in the HIV positive or HIV negative groups when the other factors were controlled for. AIDS was more common in black than white IVDA, and this increased frequency did not appear related to alcohol consumption since the distribution of heavy drinkers within each category of HIV disease did not differ within the ethnic groups.

These data indicate that a history of heavy alcohol consumption is more common in IVDA with AIDS than in IVDA at earlier stages of HIV disease.

Viruses, Immunity and Unusual Lymphoproliferative Disorders of the Chest: Integrating Imaging With Pathogenesis and Clinical Presentations

Unusual lymphoproliferative diseases result from the stimulation of intrathoracic lymphoid tissue by viruses and immune dysfunction, ranging from benign hyperplasia to malignant transformation. We review the clinical, radiological, and histopathological findings of unusual lymphoproliferative disorders, which have been linked to viruses or immune dysfunction, focusing on thoracic manifestations. Understanding these advances in science enhances the radiologist's skills in integrating the imaging findings to the clinical scenario to suggest the correct diagnosis.

HIV associated Lymphocytic Interstitial Pneumonia: a clinical, histological and radiographic study from an HIV endemic resource-poor setting

Background

There is a paucity of clinical and histopathological data about HIV-associated lymphocytic interstitial pneumonitis (LIP) in adults from HIV endemic settings. The role of Ebstein-Barr virus (EBV) in the pathogenesis remains unclear.

Methods

We reviewed the clinical, radiographic and histopathological features of suspected adult LIP cases at the Groote Schuur Hospital, Cape Town South Africa, over a 6 year period. Archived tissue sections were stained for CD3, CD4, CD8, CD20 and LMP-1 antigen (an EBV marker).

Results

42 cases of suspected LIP(100% HIV-infected) were identified. 75% of patients were empirically treated for TB prior to being referred to the chest service for further investigation. Tissue samples were obtained using trans-bronchial biopsy. 13/42 were classified as definite LIP (lymphocytic infiltrate with no alternative diagnosis), 19/42 probable LIP (lymphocytic infiltrate but evidence of anthracosis or fibrosis) and 10 as non-LIP (alternative histological diagnosis). Those with definite LIP were predominantly young females (85%) with a median CD4 count of 194 (IQR 119–359). Clinical or radiological features had poor predictive value for LIP. Histologically, the lymphocytic infiltrate comprised mainly B cells and CD8 T cells. The frequency of positive EBV LMP-1 antigen staining was similar in definite and non- LIP patients [(2/13 (15%) vs. 3/10 (30%); p = 0.52].

Conclusions

In a HIV endemic setting adult HIV-associated LIP occurs predominantly in young women. The diagnosis can often be made on transbronchial biopsy and is characterized by a predominant CD8 T cell infiltrate. No association with EBV antigen was found.

Introducing mediterranean journal of hematology and infectious diseases

Mediterranean Journal of Hematology and Infectious Diseases (MJHID) is a new open access, peer-reviewed, online journal, which encompasses different aspects of clinical and translational research providing an insight into the relationship between acute and chronic infections and hematological diseases. MJHID will be a topical journal on subjects of current importance in clinical haematology and infectious diseases. Every issue should have, beside the editor in chief, a guest editor. Both editor in chief and guest editor provide to invite experts in the selected topic to performe a complete update of the arguments readily available for practising phisicians. The journal will have also a section devoted to original papers, case reports and letters to editor and Editorial comment mostly focusing on the arguments treated in the previous topical issues.

Myocardial disease in human immunodeficiency virus (HIV) infection: a review

Heart muscle disease is the most important cardiovascular manifestation of HIV infection and is likely to become even more prevalent as HIV infected patients live longer. This may present as myocarditis, dilated cardiomyopathy or isolated left or right ventricular dysfunction. Myocardial involvement in HIV infection is multifactorial and may arise as a result of myocardial invasion with HIV itself, opportunistic infections, viral infections, autoimmune response to viral infection, drug-related cardiac toxicity, nutritional deficiencies, and prolonged immunosuppression. Both adults and children are affected with severity ranging from incidental microscopic inflammatory findings at autopsy to clinically significant cardiac disease with chronic cardiac dysfunction. It is associated with a poor prognosis, and results in symptomatic heart failure in up to 5% of HIV patients. Clinical pathological studies from the pre-HAART era show a 30% prevalence of cardiomyopathy in patients with AIDS. The introduction of highly active antiretroviral therapy (HAART) regimens has substantially modified the course of HIV disease by lengthening survival and improving quality of life of HIV-infected patients. There is also good evidence that HAART significantly reduces the incidence of cardiovascular manifestations of HIV infection. By preventing opportunistic infections and reducing the incidence of myocarditis, HAART regimens have reduced the prevalence of HIV-associated cardiomyopathy by almost 7-fold from the pre-HAART era. HAART is however only available to a minority of HIV infected individuals in most areas of the world and studies from the pre-HAART period still apply. In this review, the aetiopathogenesis and presentation of HIV related myocardial disease were reviewed and measures taken to improve survival discussed.

Viruses and rickettsiae

In this review I shall try to provide a brief, up-to-date, account of the neuropathology of those viral and rickettsial diseases that are particularly prevalent in tropical regions. These diseases are not, however, exclusive to the tropics. Some, such as AIDS, are common in temperate regions as well, though others are closer to being exclusively tropical, such as some of the arthropod-borne (ARBO) virus encephalides. The latter are dependent for their dissemination on an existence during part of their infectious cycle in insects which are, in turn, climatically and seasonally sensitive. This necessarily limits their geographical distribution. Factors that influence some of the other diseases are less closely dependent on climate and geography and reflect more the social or cultural conditions under which people live. Thus, diseases that depend for their spread on forms of human behavior such as promiscuity or drug abuse (AIDS), or poor hygiene and living conditions (polio, rickettsial diseases) or on contact with domestic and other animals (rabies) may occur in a more widespread distribution, for the tropics are not the only places that afford opportunities for these diseases to flourish. I shall select for discussion aspects of the pathology of these diseases that are currently undergoing investigation but will aim to present these against the backdrop of more established aspects of their pathology. Recent reviews of the pathology of viral encephalitis can be found in Hamilton and Wiley (33) and Esiri and Kennedy (20) and of HIV-1 infection in Price & Sidtis (78) and Scaravilli (85).

Structure–activity relationship study of flavone compounds with anti-HIV-1 integrase activity: A density functional theory study

Human immunodeficiency virus type-1 integrase (HIV-1 IN) is an essential enzyme for effective viral replication. Flavone compounds have been very much studied due to their activity during the inhibition process of HIV-1 IN. In this study, we employed density functional theory (DFT) using the B3LYP hybrid functional to calculate a set of molecular properties for 32 flavonoid compounds with anti-HIV-1 IN activity. The stepwise discriminant analysis (SDA), principal component analysis (PCA) and hierarchical cluster analysis (HCA) methods were employed to reduce dimensionality and investigate possible relationship between the calculated properties and the anti-HIV-1 IN activity. These analyses showed that the molecular hydrophobicity (ClogP), charge on atom 11 and electrophilic index (omega) are responsible for the separation between anti-HIV-1 IN active and inactive compounds.

AIDS and Recurrent Aphthous Stomatitis

The immunodeficiency state in HIV infected patients has been the cause of severe episodes of Recurrent Aphthous Stomatitis (RAS). Aim: Our study aims to establish correlation between the manifestations of RAS and the immunosuppression state caused by HIV infection, through counting of CD4+ cells, CD8+ cells, CD4+:CD8+ cells ratio and viral load. Study design: series study. Material and Method: Ninety-four HIV infected patients (25 women and 69 men) with RAS were evaluated in the ENT Department of the University of Sao Paulo-Medical School from January 1998 to December 2003. The age ranged between 19 and 63 years (mean = 35.3 years). The patients were divided in two groups: AIDS group and HIV infected group. Results: The patients with AIDS and HIV infection presented, respectively, eight ulcers and two ulcers by outbreaks. Similarly, patients with major RAS presented smaller counting of cells CD8+, CD4+ and CD4+/CD8+ cells, and higher mean value of viral load than the patients with herpetiform and minor RAS. Between patients with minor and herpetiform RAS there were no statistical differences. Conclusions: The emergence of the lesions, mainly in major RAS, is directly related to the immunological state of the HIV infected patient. These patients frequently present nutritional deficits and worsening in life style. Thus, diagnosis and treatment of RAS is a challenge that should not be neglected.

Current status of gene therapy strategies to treat HIV/AIDS

Progress in developing effective gene transfer approaches to treat HIV-1 infection has been steady. Many different transgenes have been reported to inhibit HIV-1 in vitro. However, effective translation of such results to clinical practice, or even to animal models of AIDS, has been challenging. Among the reasons for this failure are uncertainty as to the most effective cell population(s) to target, the diffuseness of these target cells in the body, and ineffective or insufficiently durable gene delivery. Better understanding of the HIV-1 replicative cycle, host factors involved in HIV-1 infection, vector biology and application, transgene technology, animal models, and clinical study design have all contributed vastly to planning current and future strategies for application of gene therapeutic approaches to the treatment of AIDS. This review focuses on the newest developments in these areas and provides a strong basis for renewed optimism that gene therapy will have an important role to play in treating people infected with HIV-1.

Cells of the central nervous system as targets and reservoirs of the human immunodeficiency virus

The availability of highly active antiretroviral therapies (HAART) has not eliminated HIV-1 infection of the central nervous system (CNS) or the occurrence of HIV-associated neurological problems. Thus, the neurobiology of HIV-1 is still an important issue. Here, we review key features of HIV-1-cell interactions in the CNS and their contributions to persistence and pathogenicity of HIV-1 in the CNS. HIV-1 invades the brain very soon after systemic infection. Various mechanisms have been proposed for HIV-1 entry into the CNS. The most favored hypothesis is the migration of infected cells across the blood-brain barrier ("Trojan horse" hypothesis). Virus production in the CNS is not apparent before the onset of AIDS, indicating that HIV-1 replication in the CNS is successfully controlled in pre-AIDS. Brain macrophages and microglia cells are the chief producers of HIV-1 in brains of individuals with AIDS. HIV-1 enters these cells by the CD4 receptor and mainly the CCR5 coreceptor. Various in vivo and cell culture studies indicate that cells of neuroectodermal origin, particularly astrocytes, may also be infected by HIV-1. These cells restrict virus production and serve as reservoirs for HIV-1. A limited number of studies suggest restricted infection of oligodendrocytes and neurons, although infection of these cells is still controversial. Entry of HIV-1 into neuroectodermal cells is independent of the CD4 receptor, and a number of different cell-surface molecules have been implicated as alternate receptors of HIV-1. HIV-1-associated injury of the CNS is believed to be caused by numerous soluble factors released by glial cells as a consequence of HIV-1 infection. These include both viral and cellular factors. Some of these factors can directly induce neuronal injury and death by interacting with receptors on neuronal membranes (neurotoxic factors). Others can activate uninfected cells to produce inflammatory and neurotoxic factors and/or promote infiltration of monocytes and T-lymphocytes, thus amplifying the deleterious effects of HIV-1 infection. CNS responses to HIV-1 infection also include mechanisms that enhance neuronal survival and strengthen crucial neuronal support functions. Future challenges will be to develop strategies to prevent HIV-1 spread in the brain, bolster intrinsic defense mechanisms of the brain and to elucidate the impact of long-term persistence of HIV-1 on CNS functions in individuals without AIDS.

Cerebrospinal fluid HIV viral load in different phases of HIV-associated brain disease

We compared CSF HIV viral load in 33 asymptomatic HIV seropositive patients, 11 patients with incipient minor motor deficits (MMD), 11 patients with sustained MMD, and 16 patients with HIV-associated dementia. Patients with incipient MMD showed significantly higher CSF viral load than asymptomatic patients. Demented patients also had higher CSF viral loads than asymptomatic patients. This phenomenon is independent of antiretroviral therapy. Thus, correlation of viral load with time suggests a multiphasic course of HIV-associated CNS disease.

Pigmentation: a potential cutaneous marker for AIDS?

Pigmentation of skin, nails and mucosae has frequently been described in HIV positive patients. Various causes for this phenomenon have been ascribed, which include intake of various drugs like zidovudine, opportunistic infections like toxoplasmosis and adrenocortical suppression. However, there has been no uniform explanation. We describe three AIDS patients with different personal and disease profiles but essentially the same pattern of pigmentation. This pattern of pigmentation is thereby discussed. We also propose that this pigmentation could be a result of late stage HIV disease per se and thus could serve as a useful cutaneous marker for the same.

« Classification 2002 des pneumopathies interstitielles idiopathiques »

OBJECTIVES

Diagnosis of interstitial lung diseases was recently improved by the use of diagnostic tools, such as high-resolution Computed Tomography, and by new insights in their pathogenesis and histology. This led the American Thoracic Society and the European Respiratory Society to propose a new classification of these diseases, in the aim to facilitate early diagnosis and specific care.

CURRENT KNOWLEDGE AND KEY POINTS

Standard radiography gives the first suspicion of chronic diffuse infiltrative lung disease, and anamnesis and physical examination are essential steps of etiological diagnosis. High-Resolution computed tomography confirms the diagnosis of diffuse infiltrative lung disease. Longitudinal lung function tests are essential to assess the consequences of the lung disease. Lung biopsies are often, but not systematically, a useful tool. The 2000 classification consists of seven entities of idiopathic interstitial diseases which are defined on clinical, radiological and pathological criteria: idiopathic pulmonary fibrosis, non-specific interstitial pneumonia, cryptogenic organizing pneumonia, acute interstitial pneumonia, respiratory bronchiolitis associated interstitial lung disease, desquamative interstitial pneumonia and lymphoid interstitial pneumonia. The most frequent is Idiopathic Pulmonary Fibrosis, which has a poor prognosis.

FUTURE PROSPECT AND PROJECTS

This new classification results from a multidisciplinary confrontation with chest physicians, radiologists and pathologists. A better characterization of anatomoclinical entities should lead to a better pronostic evaluation, more informative comparisons of published studies, and therefore to rational therapeutic approach.

Effects of HIV-1 Vpr on Neuroinvasion and Neuropathogenesis

Human immunodeficiency virus type I (HIV-1) infection leads to penetration of the central nervous system (CNS) in virtually all infected individuals and HIV-1-induced encephalopathy in a significant number of untreated patients. The molecular mechanisms by which HIV-1 enters the CNS and yields CNS dysfunction are still unclear. Our laboratories and others have begun to explore the direct effects of prioritized HIV-1-specific proteins on diverse human CNS cell types. One of these proteins, the accessory HIV-1 protein Vpr, is a critical moiety in these studies, and will be discussed in this article.

Immunopathogenesis of HIV-related heart muscle disease: current perspectives

As more effective antiretroviral therapies improve survival times, growing numbers of HIV-positive patients are at risk of developing end-organ damage or neoplasia. Heart muscle disease is the most important cardiovascular manifestation of HIV infection and seems set to become increasingly prevalent. This may take the form of either a dilated cardiomyopathy or isolated left or right ventricular dysfunction, is associated with a poor prognosis, and results in symptomatic heart failure in up to 5% of HIV patients. The precise cause of HIV-associated cardiomyopathy remains unclear but is undoubtedly complex, and most probably multifactorial. This report examines our current understanding of the immunopathogenesis of HIV-associated cardiomyopathy.

Lymphoid interstitial pneumonia: a narrative review

Lymphoid interstitial pneumonia (LIP) is regarded as both a disease and a nonneoplastic, inflammatory pulmonary reaction to various external stimuli or systemic diseases. It is an uncommon condition with incidence and prevalence rates that are largely unknown. Liebow and Carrington originally classified LIP as an idiopathic interstitial pneumonia in 1969. Although LIP had since been removed from that category, the most recent consensus classification sponsored by the American Thoracic Society and the European Respiratory Society recognizes that some cases remain idiopathic in origin, and its clinical, radiographic, and pathologic features warrant the return of LIP to its original classification among the idiopathic interstitial pneumonias. LIP also belongs within a spectrum of pulmonary lymphoproliferative disorders that range in severity from benign, small, airway-centered cellular aggregates to malignant lymphomas. It is characterized by diffuse hyperplasia of bronchus-associated lymphoid tissue. The dominant microscopic feature of LIP is a diffuse, polyclonal lymphoid cell infiltrate surrounding airways and expanding the lung interstitium. Classically, LIP occurs in association with autoimmune diseases, most often Sjögren syndrome. This has led to consideration of an autoimmune etiology for LIP, but its pathogenesis remains poorly understood. Persons who are seropositive for HIV, and children in particular, are at increased risk of acquiring LIP. Some studies suggest causal roles for both HIV and Epstein-Barr virus. The incidence of LIP is approximately twofold greater in women than men. The average age at diagnosis is between 52 years and 56 years. Symptoms of progressive cough and dyspnea predominate. There is great variability in the clinical course of LIP, from resolution without treatment to progressive respiratory failure and death. Although LIP is often regarded as a steroid-responsive condition, and oral corticosteroids continue to be the mainstay of therapy, response is unpredictable. Approximately 33 to 50% of patients die within 5 years of diagnosis, and approximately 5% of cases of LIP transform to lymphoma.

HIV-1 reservoirs

In most infected individuals, HIV-1 replicates high levels throughout the duration of infection, including the clinically quiescent phase of disease. The level of this active viral replication correlates directly with disease progression and survival. The advent of combination therapeutics for HIV-1 (i.e., highly active antiretroviral therapy [HAART]) has led to dramatic reductions in viral replication in vivo and morbidity and mortality, at least in the developed world.

Hematologic Aspects of HIV/AIDS

This review addresses various aspects of HIV infection pertinent to hematology, including the consequences of HIV infection on specific aspects of hematopoiesis and an update on the current biologic, epidemiologic and therapeutic aspects of AIDS-related lymphoma and Hodgkin's disease. The results of the expanding use of progenitor cell transplantation in HIV infected patients are also reviewed. In Section I, Dr. Scadden reviews the basis for HIV dysregulation of blood cell production, focusing on the role of the stem cell in HIV disease. T cell production and thymic function are discussed, with emphasis placed upon the mechanisms of immune restoration in HIV infected individuals. Results of clinical and correlative laboratory studies are presented. In Section II, Dr. Levine reviews the recent epidemiologic trends in the incidence of lymphoma, since the widespread availability of highly active anti-retroviral therapy (HAART). The biologic aspects of AIDS-lymphoma and Hodgkin's disease are discussed in terms of pathogenesis of disease. Various treatment options for these disorders and the role of concomitant anti-retroviral and chemotherapeutic intervention are addressed. Drs. Zaia and Krishnan will review the area of stem cell transplantation in patients with AIDS related lymphoma, presenting updated information on clinical results of this procedure. Additionally, they report on the use of gene therapy, with peripheral blood CD34+ cells genetically modified using a murine retrovirus, as a means to treat underlying HIV infection. Results of gene transfer experiments and subsequent gene marking in HIV infected patients are reviewed.

Combination genetic therapy to inhibit HIV-1

Compared with single agents, combination antilentiviral pharmacotherapy targets multiple HIV-1 functions simultaneously, maximizing efficacy and decreasing chances of escape mutations. Combination genetic therapy could theoretically enhance efficacy similarly, but delivery of even single genes to high percentages of hematopoietic cells or their derivatives has proven problematic. Because of their high efficiency of gene delivery, we tested recombinant SV40-derived vectors (rSV40s) for this purpose. We made six rSV40s, each carrying a different transgene that targeted a different lentiviral function. We tested the ability of these constructs, individually and in double and triple combinations, to protect SupT1 human T lymphoma cells from HIV-1 challenge. Single chain antibodies (SFv) against CXCR4 and against HIV-1 reverse transcriptase (RT) and integrase (IN) were used, as were polymeric TAR decoys (PolyTAR) and a dominant-negative mutant of HIV-1 Rev (RevM10). Immunostaining showed that virtually all doubly treated cells expressed both transgenes. All transgenes individually protected from HIV-1 but, except for anti-CXCR4 SFv, their effectiveness diminished as challenge doses increased from 40 through 2500 tissue culture infectious dose(50) (TCID(50))/10(6) cells. However, all combinations of transgenes protected target cells better than individual transgenes, even from the highest challenge doses. Thus, combination gene therapies may inhibit HIV-1 better than single agents, and rSV40s may facilitate delivery of multigene therapeutics.

The Biology and Evolution of HIV

▪ Abstract  This review examines the current state of knowledge about HIV/AIDS in terms of its origins, pathogenesis, genetic variation, and evolutionary biology. The HIV virus damages the host's immune system, resulting in AIDS, which is characterized by immunodeficiency, opportunistic infections, neoplasms, and neurological problems. HIV is a complex retrovirus with a high mutation rate. This mutation rate allows the virus to evade host immune responses, and evidence indicates that selection favors more virulent strains with rapid replication. While a number of controversial theories attempt to explain the origin of HIV/AIDS, phylogenetic evidence suggests a zoonotic transmission of HIV to humans and implicates the chimpanzee (Pan troglodytes troglodytes) as the source of HIV-1 infection and the sooty mangabey as the source of HIV-2 infection in human populations. New therapies provide hope for increased longevity among people living with AIDS, but the biology of HIV presents significant obstacles to finding a cure and/or vaccine. HIV continues to be a threat to the global population because of its fast mutation rate, recombinogenic effect, and its use of human defenses to replicate itself.

Clinical features and T-cell subsets in HIV-infected children with and without lymphocytic interstitial pneumonitis

Lymphocytic interstitial pneumonitis (LIP) is a non-infective lung condition common in untreated older children with vertically acquired HIV infection. Little is known about the prognosis in children with LIP, and diagnosis remains a problem where lung biopsy is not feasible. Our aim was to determine which clinical features aid the diagnosis of LIP in conjunction with the typical reticulonodular radiological picture, and whether the prognosis in children with LIP is different from that in HIV-infected children of the same age without LIP. We retrospectively compared the clinical features and T-cell subsets of 49 children with LIP with those of 56 children of similar age without LIP. Diagnosis of LIP was made radiologically. All children were apyrexial at the time of X-ray and acute intercurrent infections and tuberculosis had been excluded as far as possible. Ages ranged from 24 to 112 months in the non-LIP group and from 24 to 120 months in the LIP group. Digital clubbing and reticulo-endothelial hyperplasia were significantly more common in children with LIP than in those without. Children with LIP tended to have lower CD4+ counts and CD4% and higher CD8+ counts and CD8%, which resulted in significantly lower CD4/CD8 ratios in children under 5 years with LIP. It is possible in most cases to diagnose LIP using a combination of clinical and X-ray findings, as long as every effort is made to exclude tuberculosis. Lower CD4+ counts and CD4% as well as more frequent hospital admissions suggest that LIP adversely affects prognosis in children with HIV.

Therapeutic effects of nucleoside analogues on psychomotor slowing in HIV infection

OBJECTIVE

Since psychomotor slowing predicts the development of HIV-1-associated dementia, AIDS and death independently of the immune status, there is urgent need for a neurological therapeutic rationale.

METHODS

The therapeutic efficacy of nucleoside analogues with different abilities to penetrate into the cerebrospinal fluid was assessed in 410 HIV-1-seropositive patients using the results of detailed fine motor tests, which detect minor motor deficits. Patients were selected who showed pathological psychomotor slowing as signs of central nervous system (CNS) dysfunction before therapy onset and who were then treated only with nucleoside analogues for at least 6 months.

RESULTS

Both zidovudine and didanosine improve CNS function to an equal degree when given as monotherapy. Adding a second nucleoside analogue (didanosine, lamivudine, zalcitabine) to zidovudine does not further improve psychomotor performance. However, adding a second nucleoside after a period of zidovudine monotherapy does result in a second but less remarkable therapeutic effect. Combinations containing stavudine are as effective as those including zidovudine when given as first antiretroviral treatment. Furthermore, stavudine effectively improves motor performance even after pretreatment with zidovudine.

Neuronal glycolytic pathway impairment induced by HIV envelope glycoprotein gp120

Neurological impairment is a common feature of Acquired Immunodeficiency Syndrome (AIDS); functional alterations have been reported both in central and peripheral nervous system and the Human Immunodeficiency Virus (HIV) envelope glycoprotein gp120 has been proposed as a neurotoxin acting through a calcium-dependent mechanism. On the other hand it has been reported that gp120 treatment also induce about a 20% decrease in the cerebral glucose utilization and in the cellular ATP levels. The reported observations were performed on experimental system where also non-neuronal cells where present; in order to evaluate whether a direct interaction between HIV proteins and neuronal cells takes place, we used a neuroblastoma cultures where only neuronal cells are present. We analysed the effects of gp120 on the N18TG2 neuroblastoma clone. Treatments were performed both on growing and confluent cultures. Short time treatment with gp120 of confluent cultures causes a 25% reduction in the level of neuron-specific enolase, resulting in a similar decrease of oxygen consumption. Long time exposure of growing cells also causes a reduction in cell survival. Furthermore, using a membrane-specific fluorescent probe we observed that gp120 produces an increase of membrane trafficking. These observations suggest a direct interaction between the viral envelope protein and neuronal cells, which results in an alteration of glycolytic metabolism. This alteration may be related to the neurologic impairments observed in AIDS patients.

Cerebral infarction in adult AIDS patients: observations from the Edinburgh HIV Autopsy Cohort

BACKGROUND AND PURPOSE

Autopsy series of patients with AIDS have found a 4% to 29% prevalence of cerebral infarction. Little is known of the prevalence of cerebral infarction when not associated with non-HIV central nervous system (CNS) infection, lymphoma, or cardioembolic sources. Clinical correlation has seldom been available. We describe the pathological and clinical features of patients from the Edinburgh HIV Cohort Study found to have had cerebral infarcts without evidence of non-HIV CNS infection, CNS lymphoma, or cardioembolic sources at autopsy.

METHODS

From 183 autopsy cases, 26 without evidence of opportunistic cerebral infection or lymphoma were selected. These 26 cases went through a second selection process in which the presence of cerebral infarction, in the absence of the conditions mentioned, was verified. Histology and clinical records for the remaining patients were reviewed.

RESULTS

Ten (5.5%) cases fulfilled the inclusion criteria and demonstrated similar hypoxic-ischemic lesions. Small-vessel thickening was seen in all cases, and perivascular space dilatation, rarefaction, and pigment deposition, with vessel wall mineralization and perivascular inflammatory cell infiltrates, were seen in some cases. Vasculitis was not found. One patient had had a transient ischemic attack, and no patient had had a stroke.

CONCLUSIONS

Cerebral infarcts in HIV-infected patients are not common in the absence of cerebral non-HIV infection, lymphoma, or embolic sources. We found an HIV-associated vasculopathy with similar features in all risk groups. In AIDS patients presenting with stroke or transient ischemic attack, potentially treatable causes, such as cerebral coinfection or tumor, should be sought.

HIV-1-Associated Cognitive-Motor Disorders: A Research-Based Approach to Diagnosis and Treatment

The diagnosis of human immunodeficiency virus type 1 (HIV-1)-associated cognitive-motor disorder--either minor cognitive-motor disorder (MCMD) or HIV-1-associated dementia (HAD)--is fraught with potential pitfalls for the clinician. Before making such a diagnosis, clinicians should exclude other etiologies by using neuroimaging, lumbar puncture, and serum chemistries to screen for opportunistic and non-opportunistic infections of the brain and meninges. Clinicians should also consider psychoneurotoxicity (caused from the use of psychoactive substances and prescribed medications) and psychopathology, such as mood, anxiety, and other disorders. In addition, a thorough medical history and physical examination, including a complete neurologic and neuropsychiatric mental status examination, are necessary for an accurate diagnosis. There is also a need for standardized neuropsychological and functional status tests, since the diagnostic criteria for these disorders are partly based on these criteria. Treatment targets should include subclinical cognitive-motor impairment and neuroprotection, as well as MCMD and HAD. Currently, zidovudine remains the best proven treatment for these disorders, but other nucleoside reverse transcriptase inhibitors, as well as nonnucleoside reverse transcriptase inhibitors and protease inhibitors, show promise, and selected agents from these classes are being tested in clinical trials. Other areas that should be investigated are the modulation of inflammatory mediators (such as tumor necrosis factor alpha), neurotransmitter manipulation (especially of dopamine), and nutritional interventions.

Phosphohexose isomerase/autocrine motility factor/neuroleukin/maturation factor is a multifunctional phosphoprotein

Phosphohexose isomerase (PHI) is a member of the ectoenzyme/exoenzyme family and plays a key role in both glycolysis and gluconeogenesis pathways. Upon secretion PHI acts as a cytokine with tumor autocrine motility factor (AMF), neuroleukin (NLK) and maturation factor (MF) functions. Signaling is initiated by its binding to a cell surface 78 kDa glycoprotein (gp78). However, since PHI protein is a 'leaderless' secretory protein, released from cells via a non-classical route(s), we questioned whether the molecule undergoes post-translation modification while retaining proper folding and maintaining intact enzymatic and motogenic activities. To address this, we have generated, expressed and isolated a recombinant human AMF (rhAMF). The rhAMF retained the biological activities of the native AMF, i.e., catalyzes phosphohexose isomerization and stimulated cell motility. Additionally, we show here that human PHI is phosphorylated at serine 185 by casein kinase II (CK II) and we provide experimental evidence suggesting that this phosphorylation is associated with secretion, thus providing insights for elucidating the intracellular signal transmission of cell response to stimulation by AMF/NLK/MF.

Pathogenesis of HIV-1 infection within bone marrow cells

Mononuclear phagocytic cells and CD4+ T lymphocytes represent the major targets for infection by HIV-1 in vivo. The most severe pathogenic features associated with HIV-1 infection can be attributed to malfunction or premature death of these cells that are of hematopoietic origin. Patients with acquired immunodeficiency syndrome (AIDS), suffer from many hematologic disorders, particularly those persons with long-term infection of HIV-1. These disorders include anemia, lymphocytopenia, thrombocytopenia and neutropenia. The mechanisms that lead to the induction of these disorders are multi-factorial. However, sufficient evidence has accumulated which suggests that HIV-1 infection of cells within the microenvironment of the bone marrow can lead to the induction of hematopoietic deficits. Most studies indicate that marrow-derived hematopoietic stem cells cannot be infected by HIV-1 until they undergo modest differentiation in order to express the appropriate receptors to enable virus entry and subsequent replication. Some cells within the mixed environment of the marrow stroma appear to support HIV-1 replication however. These cells include marrow microvascular endothelial cells, sometimes referred to as blanket cells, stromal fibroblasts, as well as mononuclear phagocytes. Our recent experiments suggest that the HIV-1 accessory protein, Vpr, plays some role in the activation of marrow-derived mononuclear phagocytes which appears to result in premature phagocytosis of non-adherent marrow cells present in the in vitro cultures. This phenomenon could account, in part, for the induction of cytopenias that are typical of individuals infected by HIV-1.

Anti-human immunodeficiency virus type 1 gene therapy in human central nervous system-based cells: an initial approach against a potential viral reservoir

Studies have demonstrated that human immunodeficiency virus type 1 (HIV-1) infection of central nervous system (CNS)-based cells in vivo results in a series of devastating clinical conditions collectively termed acquired immune deficiency syndrome (AIDS) dementia complex (ADC). Gene therapy for these neurovirological disorders necessitates utilization of a vector system that can mediate in vivo delivery and long-term expression of an antiretroviral transgene in nondividing/postmitotic CNS cellular elements. The present studies focus on the transfer of an anti-HIV-1 gene to primary isolated CNS microvascular endothelial cells (MVECs) and neuronal-based cells, for its effects in protecting these cells from HIV-1 infection. By using an HIV-1-based vector system, it was possible to efficiently transduce and maintain expression of a marker transgene, beta-galactosidase (beta-Gal), in human CNS MVECs, human fetal astrocytes, plus immature and mature (differentiated) NT2 cells. Significant transduction of the marker gene, beta-Gal, in CNS-based cells prompted the utilization of this system with an anti-HIV-1 gene therapeutic construct, RevM10, a trans-dominant negative mutant Rev protein. Initially, it was not possible to generate any HIV-1 vector particles with the RevM10 gene in the transducing construct, because of inhibitory effects on the HIV-1 vector by this gene product. However, the vector could be partially rescued by adding an additional construct that supplied wild-type rev, in trans, during a multiple construct transfection in the packaging 293T cells. Thus, it was possible to significantly improve the titer of RevM10-expressing viral particles generated from these cells. Moreover, this RevM10 vector transduced the neuronal precursor cell line NT2, retinoic acid-differentiated human neurons (hNT) from the precursor cells, and primary isolated human brain MVECs with high efficiency. RevM10 generated from the HIV-1-based vector system potently inhibited replication of diverse HIV-1 strains in human CNS MVECs and neuronal cells. The data generated from these studies represent an initial approach for future development of anti-HIV-1 gene therapy in the CNS.

Adenoidal tissue mass as a clinical guide of disease evolution in vertically HIV-1 infected children

INTRODUCTION

it is known that in early-stage HIV-induced disease there is a discrepancy between the levels of viral burden and virus replication in peripheral blood versus lymphoid organs. HIV disease is active in the lymphoid tissue throughout the period of clinical latency. However, it is not known how long term progression of HIV infection is influenced by short-term changes in the adenoidal size.

OBJECTIVE

To assess the reliability of adenoidal-nasopharyngeal (AN) ratio in predicting clinical evolution of pediatric HIV infection.

METHODS

lateral radiographs of the nasopharynx in 94 Caucasian children born to HIV-1-infected mothers ranged from 6 months to 15 years (60 children infected with HIV-1 and 34 without HIV infection), and in a control group of 692 normal children were evaluated to obtain the AN ratio in order to identify the relationship of AN profiles with different stages of the disease. Patients were rated regarding their clinical and immunological status according to the Center for Disease Control Classification.

RESULTS

statistically significant differences between the groups of HIV-1-infected children, seroreverters and controls in the AN ratio were found (P < 0.001). Moreover, significant differences were also found in individual children that correlated with clinical progression.

CONCLUSION

examination of radiographic changes in adenoidal size by AN ratio in relation to clinical status during one year period in the whole group showed strong prognostic value. These findings may have important implications in the design of therapeutic strategies.

Cytomegalovirus infection and HIV-1 disease progression in infants born to HIV-1-infected women. Pediatric Pulmonary and Cardiovascular Complications of Vertically Transmitted HIV Infection Study Group

BACKGROUND AND METHODS

Cytomegalovirus (CMV) has been implicated as a cofactor in the progression of human immunodeficiency virus type 1 (HIV-1) disease. We assessed 440 infants (75 of whom were HIV-1-infected and 365 of whom were not) who had known CMV status and were born to HIV-1-infected women and who were followed prospectively. HIV-1 disease progression was defined as the presence of class C symptoms (according to the criteria of the Centers for Disease Control and Prevention [CDC]) or CD4 counts of less than 750 cells per cubic millimeter by 1 year of age and less than 500 cells per cubic millimeter by 18 months of age.

RESULTS

At birth the frequency of CMV infection was similar in the HIV-1-infected and HIV-1-uninfected infants (4.3 percent and 4.5 percent, respectively), but the HIV-1-infected infants had a higher rate of CMV infection at six months of age (39.9 percent vs. 15.3 percent, P=0.001) and continued to have a higher rate of CMV infection through four years of age (P=0.04). By 18 months of age, the infants with both infections had higher rates of HIV-1 disease progression (70.0 percent vs. 30.4 percent, P=0.001), CDC class C symptoms or death (52.5 percent vs. 21.7 percent, P=0.008), and impaired brain growth or progressive motor deficits (35.6 percent vs. 8.7 percent, P=0.005) than infants infected only with HIV-1. In a Cox regression analysis, CMV infection was associated with an increased risk of HIV-1 disease progression (relative risk, 2.59; 95 percent confidence interval, 1.13 to 5.95). Among children infected with HIV-1 alone, but not among those infected with both viruses, children with rapid progression of HIV-1 disease had higher mean levels of HIV-1 RNA than those with slower or no progression of disease.

CONCLUSIONS

HIV-1-infected infants who acquire CMV infection in the first 18 months of life have a significantly higher rate of disease progression and central nervous system disease than those infected with HIV-1 alone.

Human immunodeficiency virus type 1 in the semen of men receiving highly active antiretroviral therapy

BACKGROUND

Highly active antiretroviral therapy can effectively decrease the levels of human immunodeficiency virus type 1 (HIV-1) virions in peripheral plasma and seminal fluid of infected men. Whether the genital tract of HIV-1-infected men who are receiving highly active antiretroviral therapy and who have no detectable virus in the peripheral plasma harbors replication-competent virus is not known.

METHODS

We collected peripheral-blood and semen samples from seven men with HIV-1 infections who were receiving highly active antiretroviral therapy and who had no detectable viral RNA (fewer than 50 copies per milliliter) in plasma and analyzed the samples for cell-associated proviral DNA using a quantitative polymerase-chain-reaction assay. Replication-competent viruses were evaluated by cell-coculture assays. Proviral DNA and replication-competent virus obtained from peripheral-blood and seminal cells were also analyzed by sequencing relevant viral genes.

RESULTS

Despite the long-term suppression of HIV-1 RNA in the plasma of the seven men, proviral DNA was detected in seminal cells in four. Replication-competent viruses were recovered from peripheral-blood cells in three men and from the seminal cells in two of these three men. The viruses recovered from the seminal cells had no genotypic mutations suggestive of resistance to antiretroviral drugs and were macrophage-tropic, a feature that is characteristic of HIV-1 strains that are capable of being sexually transmitted.

CONCLUSIONS

In HIV-1-infected men who are receiving highly active antiretroviral therapy and who have no detectable levels of viral RNA in plasma the virus may be present in seminal cells and therefore may be capable of being transmitted sexually.

How HIV resists eradication

Successfully treated patients with no evidence of plasma viremia may continue to harbor stable reservoirs of HIV at multiple sites, including those shielded by blood-tissue barriers. HIV may be controllable, but few believe that it can be eradicated with the limited group of agents now available. Creative new pharmacologic strategies are needed, as well as increased commitment to the development of a safe and effective vaccine.

Clotting factor concentrates and immune function in haemophilic patients

Patients with haemophilia often exhibit a variety of disturbances in immune function. Although infections with HIV, hepatitis and other viruses no doubt contribute to these abnormalities, chronic exposure to extraneous proteins in clotting factor concentrates (CFCs) may also play a role. Numerous in vitro and ex vivo studies show that protein contaminants--such as immunoglobulins, fibrinogen and fibronectin--can depress various immune function indicators. Generally, such studies show that intermediate-purity CFCs are more inhibitory than very high-purity (e.g. monoclonal-purified) CFCs. In many, but not all, studies, the degree of immunosuppression correlates with the amount of intermediate-purity CFC administered over time. Among various indicators of immune function, CD4+ lymphocyte number is a marker for the progression of HIV infection, and maintenance of CD4+ number is associated with delayed progression. A number of studies suggest that, compared with intermediate-purity CFCs, use of very high-purity CFCs is associated with longer preservation of this class of lymphocytes. However, it remains to be seen whether this translates to improved long-term clinical outcomes. Further research is needed on the impact of CFCs on the immune system. For the time being, however, evidence to date favours the use of very high-purity products because they appear to preserve immune function and reduce the risk of infection with hepatitis and other viruses.

Human immunodeficiency virus infection in pregnancy

The pace at which our knowledge and treatment of the human immunodeficiency virus (HIV) has advanced has been staggering. A disease that was unknown two decades ago, that was untreatable only a decade ago, and whose rate of mother-to-child transmission was immutable just 5 years ago, is now readily diagnosed, treated with increasing effectiveness, and blocked from transmission in the large majority of cases. None of these advances can be provided to patients unless their physicians actively screen patients and, for those identified as HIV infected, assure them of access to the latest therapies. This article is a primer for those obstetricians who would engage in such efforts. The data that form the basis of therapy are provided as well as clinical guidelines for the care of the pregnant woman infected with HIV.

Cardiac manifestations of HIV/AIDS: a review of disease spectrum and clinical management

HIV and AIDS involve multiple organ systems. Lungs, brain, skin, gastrointestinal tract, kidneys, and heart are the major organs targeted by the direct effects of HIV infection and the secondary opportunistic complications of AIDS. Although most other organ system involvement has been extensively described in numerous studies and reviews, cardiac abnormalities related to HIV infection have remained less well characterized, partially because their pathogenesis was less clear and their clinical significance was uncertain. Most studies that have described cardiac complications in AIDS patients were postmortem, although some clinical series have been reported. It is now clear that cardiac involvement in AIDS patients is relatively common. Although most such conditions are clinically quiescent, some may have devastating and fatal outcomes. Pericardial effusion and myocarditis are among the most commonly reported abnormalities. Cardiomyopathy, endocarditis, and coronary vasculopathy have also been reported. In this review, we discuss the most common cardiac abnormalities in HIV-infected patients, as well as their clinical significance, clinical presentation, and management.

TXU (anti-CD7)-pokeweed antiviral protein as a potent inhibitor of human immunodeficiency virus

We have evaluated the clinical potential of TXU (anti-CD7)-pokeweed antiviral protein (PAP) immunoconjugate (TXU-PAP) as a new biotherapeutic anti-human immunodeficiency virus (anti-HIV) agent by evaluating its anti-HIV type 1 (anti-HIV-1) activity in vitro, as well as in a surrogate human peripheral blood lymphocyte-severe combined immunodeficient (Hu-PBL-SCID) mouse model of human AIDS. The present report documents in a side-by-side comparison the superior in vitro anti-HIV-1 activity of TXU-PAP compared to the activities of zidovudine, 2',3'-didehydro-2',3'-dideoxythymidine, unconjugated PAP, and B53-PAP, an anti-CD4-PAP immunoconjugate. Notably, TXU-PAP elicited potent anti-HIV activity in the Hu-PBL-SCID mouse model of human AIDS without any side effects and at doses that were very well tolerated by cynomolgus monkeys. Furthermore, plasma samples from TXU-PAP-treated cynomolgus monkeys showed potent anti-HIV-1 activity in vitro.

A preliminary study to determine the effect of an infusion of cryopreserved autologous lymphocytes on immunocompetence and viral load in HIV-infected patients

Therapeutic measures aimed at boosting the immunity of HIV-infected patients are a critical component of strategies for effective therapy of HIV and AIDS. To improve immunocompetence in patients with progressive disease, autologous lymphocytes that were collected and cryopreserved earlier in the course of HIV-infection were reinfused. None of the 12 patients receiving cell infusions experienced any adverse effects. Improvements in immunologic parameters (CD4+ counts, CD8+ counts, or both; HIV-specific cytotoxic T-lymphocyte (CTL) activity; or viral load) were seen in seven patients. Restoration of the CD4+ count to the level recorded at the time of cell harvest was achieved in two patients with less advanced disease. Plasma HIV RNA was reduced by >0.5 logs in two of the four patients tested. These preliminary results suggest that cellular immunotherapy using cryopreserved autologous lymphocytes has the potential to improve some measures of immunity in patients with HIV/AIDS and warrants further investigation.

Early increase of CD4+ CD45RA+ and CD4+ CD95- cells with conserved repertoire induced by anti-retroviral therapy in HIV-infected patients

Administration of anti-retroviral drugs induces a decrease of viral load associated with increase of CD4+ cell count in most HIV-infected patients. To investigate the early changes in CD4+ cell phenotype induced by anti-retroviral therapy, six patients with CD4+ cell count > 100/mm3 and never treated with anti-HIV therapy were enrolled and blood samples collected several times within 14 days from the initiation of therapy with Zidovudine plus Didanosine. CD4+ cell count and HIV viraemia were investigated at each time point, as well as the expression of CD45RA, CD45RO and CD95/Fas molecules on CD4+ cells, and the T cell receptor (TCR) Vbeta repertoire of CD4+ cells. All patients showed a rapid and dramatic decrease in viral load with a corresponding increase of CD4+ cell count. The main remodelling of CD4+ cell subpopulations took place in the first 14 days of therapy, and consisted of: (i) increased CD4+CD45RA+/CD4+CD45RO+ ratio; (ii) decrease of CD95/Fas expression. The rise in absolute number of CD4+CD45RA+ cells was paralleled by an increase of CD4+CD95/Fas- cells and accounted for most of the early increment of CD4+ cell count. The TCR Vbeta repertoire of CD4+ cells was conserved after anti-HIV therapy, with the exception of two patients with expanded CD4+Vbeta12+ cells, which also tested CD45RA+ and CD95/Fas-. These experiments show that newcomer CD4+ lymphocytes are CD45RA+CD95/Fas- cells, suggesting that blocking HIV replication causes an early and antigen-independent proliferation of possibly 'naive' cells unprimed for CD95/Fas-mediated apoptosis. These cells expressed a conserved and widespread TCR repertoire, suggesting that their capability for antigenic recognition is intact.

Relationship between human immunodeficiency virus-associated dementia and viral load in cerebrospinal fluid and brain

Cerebrospinal fluid (CSF) human immunodeficiency virus (HIV) RNA levels were measured with the Nucleic Acid Sequence-Based Amplification (NASBA) assay to determine the relationship with neurological status; 37 subjects with HIV dementia (HIV-D) were compared with 77 with HIV with minor neurological signs (HIV-MCMD) and 93 neurologically normal HIV-seropositive individuals (HIV-NML). The NASBA assay had a lower limit of detection of 100 copies per milliliter. Mean CSF log HIV RNA levels were significantly higher in those with dementia after adjusting for CD4 count and were correlated with dementia severity. Plasma levels did not distinguish comparably immunosuppressed subjects with or without dementia. CSF and plasma RNA levels were significantly intercorrelated for subjects with CD4 counts <200/mm3 and also correlated inversely with CSF beta2-microglobulin. CSF RNA levels were independent of CSF pleocytosis or antiretroviral exposure. Brain RNA levels were consistently higher than CSF but correlated with CSF values for dementia subjects. The NASBA assay can be used reliably to determine HIV RNA levels in CSF, brain, and plasma samples. CSF HIV RNA may be a surrogate marker for brain infection, based on the observed correlation with brain levels. The association between plasma HIV RNA and CSF levels of HIV and beta2-microglobulin suggests that both viral load and CNS immune activation are important determinants of neurological disease.

SIV infection of macaques: a model for studying AIDS and drug abuse

Rhesus monkeys (Macaca mulatta) and the simian immunodeficiency virus (SIV) were used as an animal model system to evaluate longitudinally the effects of opioid dependence on the development of AIDS. Results have shown that in addition to weakening the host's T cell and PMN functions, chronic opioid treatment of SIVmac239-infected animals caused (a) an increased virus replication rate, (b) an increased rate of viral mutation, (c) a nascent humoral (antibody) response against mutated autologous strains of virus, (d) an alteration of CD8 + cell-mediated immunity toward the mutant virus, (e) an increased tolerance of AZT among the infectious virus and (f) a shorter life span for the infected animals. These results suggest that chronic administration of opioids alters general fundamental aspects of the AIDS viremia.