Persistent HIV transcription and variable antiretroviral drug penetration in lymph nodes during plasma viral suppression

OBJECTIVE

The ability of antiretroviral drugs to penetrate and suppress viral replication in tissue reservoir sites is critical for HIV remission. We evaluated antiretroviral concentrations in lymph nodes and their impact on HIV transcription.

METHODS

Participants of the RV254/SEARCH010 Acute HIV Infection Cohort in Thailand were enrolled. Group 1 (n  = 6) initiated and continued antiretrovirals with two nucleoside reverse transcriptase inhibitors (NRTIs), dolutegravir (DTG) and mar- aviroc (MVC). Group 2 (n = 12) initiated antiretrovirals with two NRTIs as well as efavirenz and were switched to two NRTIs as well as DTG. Antiretroviral concentrations were measured by mass spectroscopy. HIV RNA+ and DNA+ cells were measured by in-situ hybridization.

RESULTS

All participants were MSM. At lymph node biopsy, all had plasma HIV RNA less than 20 copies/ml. Group 2 had longer durations of antiretroviral and DTG use (medians of 135 and 63 weeks, respectively) compared with Group 1 (median 44 weeks for both). TFV-DP, 3TC-TP, DTG and MVC were quantifiable in all lymph node samples from participants receiving those drugs versus carbovir-triphosphate (CBV-TP) in four out of 14. Median ratios of lymph node to peripheral blood concentrations were DTG, 0.014; MVC, 6.9; CBV-TP, 0.38; 3TC-TP, 0.32; and TFV-DP, 3.78. Median inhibitory quotients [ratios of lymph node concentrations to in-vitro inhibitory levels (IC50-or-90)] were DTG, 0.8; MVC, 38.8; CBV-TP, 0.5; 3TC- TP, 4.1; and TFV-DP, 1.8. Ongoing viral transcription was detected in lymph node of all participants. Median lymph node RNA+ cells were 71 350 versus 99 750 cells/g for Groups 1 and 2, respectively (P = 0.111).

CONCLUSION

MVC has enhanced lymph node penetration and thereby may contribute to more complete viral suppression in the lymph node.

Losartan to reduce inflammation and fibrosis endpoints in HIV disease

BACKGROUND

Persistent inflammation and incomplete immune recovery among persons with HIV (PHIV) are associated with increased disease risk. We hypothesized that the angiotensin receptor blocker (ARB) losartan would reduce inflammation by mitigating nuclear factor (NF)κB responses and promote T-cell recovery via inhibition of transforming growth factor-beta (TGFβ)-mediated fibrosis.

METHODS

Losartan (100 mg) versus placebo over 12 months was investigated in a randomized (1 : 1) placebo-controlled trial, among PHIV age at least 50 years, receiving antiretroviral therapy (ART), with HIV RNA less than 200 copies/ml and CD4+ cell count 600 cells/μl or less. Inflammation, fibrosis and myocardial biomarkers were measured in blood using ELISA, electrochemiluminescence and immunoturbidimetric methods, and T-cell and monocyte phenotypes were assessed with flow cytometry among a subset of participants. Changes over follow-up in (log-2 transformed) biomarkers and cell phenotypes (untransformed) were compared between losartan and placebo arms using linear mixed models.

RESULTS

Among 108 PHIV (n = 52 to losartan; n = 56 to placebo), 97% had a month 12 visit. Median age was 57 years and baseline CD4+ cell count was 408 cells/μl. Losartan treatment was not associated with an improvement in interleukin-6 levels, or other blood measures of inflammation, immune activation, fibrosis activity or myocardial function. CD4+ and CD8+ T cells also did not differ by treatment group. Losartan reduced SBP and DBP by 6 and 5 mmHg, respectively.

CONCLUSION

Among older PHIV with viral suppression, losartan did not improve blood measures of inflammation nor T-cell immune recovery. Losartan treatment is unlikely to reduce inflammation associated comorbidities to a clinically meaningful degree, beyond the benefits from lowering blood pressure.

CLINICALTRIALSGOV

NCT02049307.

Understanding the renin-angiotensin-aldosterone-SARS-CoV axis: a comprehensive review

Importance

Coronavirus disease 2019 (COVID-19), the disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has been declared a global pandemic with significant morbidity and mortality since first appearing in Wuhan, China, in late 2019. As many countries are grappling with the onset of their epidemics, pharmacotherapeutics remain lacking. The window of opportunity to mitigate downstream morbidity and mortality is narrow but remains open. The renin–angiotensin–aldosterone system (RAAS) is crucial to the homeostasis of both the cardiovascular and respiratory systems. Importantly, SARS-CoV-2 utilises and interrupts this pathway directly, which could be described as the renin–angiotensin–aldosterone–SARS-CoV (RAAS–SCoV) axis. There exists significant controversy and confusion surrounding how anti-hypertensive agents might function along this pathway. This review explores the current state of knowledge regarding the RAAS–SCoV axis (informed by prior studies of SARS-CoV), how this relates to our currently evolving pandemic, and how these insights might guide our next steps in an evidence-based manner.

Observations

This review discusses the role of the RAAS–SCoV axis in acute lung injury and the effects, risks and benefits of pharmacological modification of this axis. There may be an opportunity to leverage the different aspects of RAAS inhibitors to mitigate indirect viral-induced lung injury. Concerns have been raised that such modulation might exacerbate the disease. While relevant preclinical, experimental models to date favour a protective effect of RAAS–SCoV axis inhibition on both lung injury and survival, clinical data related to the role of RAAS modulation in the setting of SARS-CoV-2 remain limited.

Conclusion

Proposed interventions for SARS-CoV-2 predominantly focus on viral microbiology and aim to inhibit viral cellular injury. While these therapies are promising, immediate use may not be feasible, and the time window of their efficacy remains a major unanswered question. An alternative approach is the modulation of the specific downstream pathophysiological effects caused by the virus that lead to morbidity and mortality. We propose a preponderance of evidence that supports clinical equipoise regarding the efficacy of RAAS-based interventions, and the imminent need for a multisite randomised controlled clinical trial to evaluate the inhibition of the RAAS–SCoV axis on acute lung injury in COVID-19.

The interplay of SARS-CoV-2 with the renin–angiotensin–aldosterone system probably accounts for much of its unique pathology. Appreciating the degree and mechanism of this interaction highlights potential therapeutic options, including blockade (ARBs).https://bit.ly/3aue4tS

Recommendations for analytical antiretroviral treatment interruptions in HIV research trials-report of a consensus meeting

Analytical antiretroviral treatment interruption (ATI) is an important feature of HIV research, seeking to achieve sustained viral suppression in the absence of antiretroviral therapy (ART) when the goal is to measure effects of novel therapeutic interventions on time to viral load rebound or altered viral setpoint. Trials with ATIs also intend to determine host, virological, and immunological markers that are predictive of sustained viral control off ART. Although ATI is increasingly incorporated into proof-of-concept trials, no consensus has been reached on strategies to maximise its utility and minimise its risks. In addition, differences in ATI trial designs hinder the ability to compare efficacy and safety of interventions across trials. Therefore, we held a meeting of stakeholders from many interest groups, including scientists, clinicians, ethicists, social scientists, regulators, people living with HIV, and advocacy groups, to discuss the main challenges concerning ATI studies and to formulate recommendations with an emphasis on strategies for risk mitigation and monitoring, ART resumption criteria, and ethical considerations. In this Review, we present the major points of discussion and consensus views achieved with the goal of informing the conduct of ATIs to maximise the knowledge gained and minimise the risk to participants in clinical HIV research.

Transplantation of CCR5∆32 Homozygous Umbilical Cord Blood in a Child With Acute Lymphoblastic Leukemia and Perinatally Acquired HIV Infection

Background

Allogeneic hematopoietic cell transplantation (allo-HCT) in a CCR5∆32 homozygous donor resulted in HIV cure. Understanding how allo-HCT impacts the HIV reservoir will inform cure strategies.

Methods

A 12-year-old with perinatally acquired, CCR5-tropic HIV and acute lymphoblastic leukemia underwent myeloablative conditioning and umbilical cord blood (UCB) transplantation from a CCR5∆32 homozygous donor. Peripheral blood mononuclear cells (PBMCs) and the rectum were sampled pre- and post-transplant. The brain, lung, lymph node (LN), stomach, duodenum, ileum, and colon were sampled 73 days after transplantation (day +73), when the patient died from graft-vs-host disease. Droplet digital polymerase chain reaction (ddPCR) and in situ hybridization (ISH) were used detect the HIV reservoir in tissues. CCR5 and CD3 expression in the LN was assessed using immunohistochemistry (IHC).

Results

HIV DNA (vDNA) was detected in PBMCs by ddPCR pretransplant but not post-transplant. vDNA was detected by ISH in the rectum at days –8 and +22, and in the LN, colon, lung, and brain day +73. vDNA was also detected in the lung by ddPCR. IHC revealed CCR5+CD3+ cells in the LN postmortem.

Conclusions

HIV was detected in multiple tissues 73 days after CCR5∆32 homozygous UCB allo-HCT despite myeloablative conditioning and complete donor marrow engraftment. These results highlight the importance of analyzing tissue during HIV cure interventions and inform the choice of assay used to detect HIV in tissue reservoirs.

Multiple Origins of Virus Persistence during Natural Control of HIV Infection

Targeted HIV cure strategies require definition of the mechanisms that maintain the virus. Here, we tracked HIV replication and the persistence of infected CD4 T cells in individuals with natural virologic control by sequencing viruses, T cell receptor genes, HIV integration sites, and cellular transcriptomes. Our results revealed three mechanisms of HIV persistence operating within distinct anatomic and functional compartments. In lymph node, we detected viruses with genetic and transcriptional attributes of active replication in both T follicular helper (TFH) cells and non-TFH memory cells. In blood, we detected inducible proviruses of archival origin among highly differentiated, clonally expanded cells. Linking the lymph node and blood was a small population of circulating cells harboring inducible proviruses of recent origin. Thus, HIV replication in lymphoid tissue, clonal expansion of infected cells, and recirculation of recently infected cells act together to maintain the virus in HIV controllers despite effective antiviral immunity.

IL-15 drives CD8 T cell cycling and differentiation in chronic HIV-1 infection (VIR6P.1162)

HIV-1 infection is characterized by sustained CD8 T cell expansion that is linked to morbid outcomes even after HIV replication is controlled with antiretroviral therapy (ART). The drivers of this persistent CD8 expansion in HIV-1 infection are not well understood. Here we show that cycling frequency is increased in memory CD8 T cells in untreated HIV-1 infected patients and cycling CD8 T cells have a broad T cell receptor repertoire tightly linked to the repertoire of non-cycling cells suggesting that they are largely driven into cycle by bystander mechanisms. In HIV-1 infection, cycling and granzyme B expression were increased among CD8 T cells binding viral peptide/HLA tetramers and this enriched cycling/cytolytic phenotype among virus-reactive CD8 T cells could be generated in vitro by exposure to interleukin (IL)-15. Lymph nodes of HIV-1 infected untreated patients were enriched for interleukin-15 expression that correlated with circulating CD8 T cell counts and normalized with drug-induced control of HIV-1 replication. The determinants of persistent CD8 T cell expansion and the mechanisms whereby this expansion is linked to increased morbidity merit further examination.

Challenges in detecting HIV persistence during potentially curative interventions: a study of the Berlin patient

There is intense interest in developing curative interventions for HIV. How such a cure will be quantified and defined is not known. We applied a series of measurements of HIV persistence to the study of an HIV-infected adult who has exhibited evidence of cure after allogeneic hematopoietic stem cell transplant from a homozygous CCR5Δ32 donor. Samples from blood, spinal fluid, lymph node, and gut were analyzed in multiple laboratories using different approaches. No HIV DNA or RNA was detected in peripheral blood mononuclear cells (PBMC), spinal fluid, lymph node, or terminal ileum, and no replication-competent virus could be cultured from PBMCs. However, HIV RNA was detected in plasma (2 laboratories) and HIV DNA was detected in the rectum (1 laboratory) at levels considerably lower than those expected in ART-suppressed patients. It was not possible to obtain sequence data from plasma or gut, while an X4 sequence from PBMC did not match the pre-transplant sequence. HIV antibody levels were readily detectable but declined over time; T cell responses were largely absent. The occasional, low-level PCR signals raise the possibility that some HIV nucleic acid might persist, although they could also be false positives. Since HIV levels in well-treated individuals are near the limits of detection of current assays, more sensitive assays need to be developed and validated. The absence of recrudescent HIV replication and waning HIV-specific immune responses five years after withdrawal of treatment provide proof of a clinical cure.

There is intense interest in developing a cure for HIV. How such a cure will be quantified and defined is not known. We applied a series of measurements of HIV persistence to the study of an HIV+ adult who has exhibited evidence of cure after a stem cell transplant. Samples from blood, spinal fluid, lymph node, and gut were analyzed in multiple laboratories using different approaches. No HIV was detected in blood cells, spinal fluid, lymph node, or small intestine, and no infectious virus was recovered from blood. However, HIV was detected in plasma (2 laboratories) and HIV DNA was detected in the rectum (1 laboratory) at levels considerably lower than those expected in antiretroviral treated patients. The occasional, low-level HIV signals might be due to persistent HIV or might reflect false positives. The sensitivity of the current generation of assays to detect HIV RNA, HIV DNA, and infectious virus are close to the limits of detection. Improvements in these tests will be needed for future curative studies. The lack of rebounding virus after five years without therapy, the failure to isolate infectious virus, and the waning HIV-specific immune responses all indicate that the Berlin Patient has been effectively cured.

Interferon-α is the primary plasma type-I IFN in HIV-1 infection and correlates with immune activation and disease markers

Type-I interferon (IFN-I) has been increasingly implicated in HIV-1 pathogenesis. Various studies have shown elevated IFN-I and an IFN-I-induced gene and protein expression signature in HIV-1 infection, yet the elevated IFN-I species has not been conclusively identified, its source remains obscure and its role in driving HIV-1 pathogenesis is controversial. We assessed IFN-I species in plasma by ELISAs and bioassay, and we investigated potential sources of IFN-I in blood and lymph node tissue by qRT-PCR. Furthermore, we measured the effect of therapeutic administration of IFNα in HCV-infected subjects to model the effect of IFNα on chronic immune activation. IFN-I bioactivity was significantly increased in plasma of untreated HIV-1-infected subjects relative to uninfected subjects (p = 0.012), and IFNα was the predominant IFN-I subtype correlating with IFN-I bioactivity (r = 0.658, p<0.001). IFNα was not detectable in plasma of subjects receiving anti-retroviral therapy. Elevated expression of IFNα mRNA was limited to lymph node tissue cells, suggesting that peripheral blood leukocytes are not a major source of IFNα in untreated chronic HIV-1 infection. Plasma IFN-I levels correlated inversely with CD4 T cell count (p = 0.003) and positively with levels of plasma HIV-1 RNA and CD38 expression on CD8 T cells (p = 0.009). In hepatitis C virus-infected subjects, treatment with IFN-I and ribavirin increased expression of CD38 on CD8 T cells (p = 0.003). These studies identify IFNα derived from lymph nodes, rather than blood leukocytes, as a possible source of the IFN-I signature that contributes to immune activation in HIV-1 infection.

SIVmac251 infection of Rhesus Macaques destroys secondary lymphoid tissue architecture and depletes naïve T cell populations (45.9)

The organized stromal cell network of secondary lymphoid tissue constitutes a microenvironment that plays a critical role in naïve T cells homeostasis, by providing survival factors such as interleukin-7 (IL-7). We previously showed that collagen deposition and damage to the lymphatic tissue niche in the course of HIV-1 infection contributes to CD4 T cell depletion and limits immune reconstitution with antiretroviral therapy. However, the mechanisms behind it have yet to be defined. Here we show in the SIV-rhesus macaque (Macaca mulatta; RMs) model, that collagen deposition and progressive loss of the stromal cell network limit both access and the source of interleukin-7 on which survival particularly of naïve T cells depends, and, consequently, greatly increased apoptosis results in progressive depletion of both naïve CD4 and CD8 T cell populations. We further show that the loss of the network and T cell depletion are interrelated by the stromal cell network’s dependence on lymphotoxin-beta produced by T cells. Thus, T cell depletion is a multiplicative and progressive pathological process involving access and interdependencies of T cells and supporting lymphatic tissue architecture.

Differential Th17 CD4 T-cell depletion in pathogenic and nonpathogenic lentiviral infections

Acute HIV infection is characterized by massive loss of CD4 T cells from the gastrointestinal (GI) tract. Th17 cells are critical in the defense against microbes, particularly at mucosal surfaces. Here we analyzed Th17 cells in the blood, GI tract, and broncheoalveolar lavage of HIV-infected and uninfected humans, and SIV-infected and uninfected sooty mangabeys. We found that (1) human Th17 cells are specific for extracellular bacterial and fungal antigens, but not common viral antigens; (2) Th17 cells are infected by HIV in vivo, but not preferentially so; (3) CD4 T cells in blood of HIV-infected patients are skewed away from a Th17 phenotype toward a Th1 phenotype with cellular maturation; (4) there is significant loss of Th17 cells in the GI tract of HIV-infected patients; (5) Th17 cells are not preferentially lost from the broncheoalveolar lavage of HIV-infected patients; and (6) SIV-infected sooty mangabeys maintain healthy frequencies of Th17 cells in the blood and GI tract. These observations further elucidate the immunodeficiency of HIV disease and may provide a mechanistic basis for the mucosal barrier breakdown that characterizes HIV infection. Finally, these data may help account for the nonprogressive nature of nonpathogenic SIV infection in sooty mangabeys.

Simian immunodeficiency virus-induced intestinal cell apoptosis is the underlying mechanism of the regenerative enteropathy of early infection

The enteropathic manifestations of the human immunodeficiency virus (HIV) and the simian immunodeficiency virus (SIV) in late infection are usually due to infection by other microbes, but in early infection the viruses themselves cause an enteropathy by heretofore undetermined mechanisms. Here we report that SIV induces massive apoptosis of intestinal epithelial cells lining the small and large bowel, thus identifying apoptosis as the driving force behind the regenerative pathology of early infection. We found that apoptosis of gut epithelium paralleled the previously documented apoptosis and massive depletion of CD4 T cells in gut lamina propria, triggered by established mechanisms of gut epithelial cell apoptosis and, at peak, possibly by virus interactions with GPR15/Bob, an intestinal epithelial cell-associated alternative coreceptor for SIV and HIV-1. Apoptosis in early SIV infection is thus the common theme of the pathological processes that quickly afflict the innate as well as adaptive arms of the gut immune system.

An update on short-course episodic and prevention therapies for herpes genitalis

The prevalence of herpes genitalis (genital herpes) has increased markedly over the past three decades. The most common cause is infection with the herpes simplex virus type 2 (HSV-2), but it can also occur as a result of HSV-1 infection. Herpes genitalis can cause substantial psychosexual as well as physical morbidity and, in immunocompromised individuals, such as those who are HIV-positive, HSV infection can result in severe disease with progressive and extensive lesions. The natural history of herpes genitalis and the pathways of infection are now well known; however, the factors associated with reactivation have yet to be fully defined. A number of management approaches with antiviral medications are commonly used, including episodic and suppressive treatments. For episodic therapy, the duration of both lesions and symptoms, as well as the proportion of aborted episodes, are the most important measures of efficacy. For suppressive therapy, the time to first recurrence and frequency of recurrences over time are the most important clinical measures of antiviral benefit. Regarding the duration of episodic regimens, comparisons of 1-, 2- and 3-day antiviral courses with standard 5-day regimens show similar benefits on healing and relief of symptoms, with the obvious improvement in convenience, economy and compliance. In HIV-positive patients, antiherpes therapy has proved effective in speeding healing of lesions and reducing subclinical shedding, and can be used to treat genital HSV-2 infections in this group. Suppressive antiviral therapy has been shown to decrease the risk of HSV transmission in heterosexual couples. New approaches to the prevention of HSV infection, including vaccines and topical microbicides, are under investigation.

Simian Immunodeficiency Virus–Induced Lymphatic Tissue Fibrosis Is Mediated by Transforming Growth Factor β1–Positive Regulatory T Cells and Begins in Early Infection

In human immunodeficiency virus (HIV) infection, collagen deposition and fibrosis within the T cell zone disrupt the lymphatic tissue architecture, contributing to depletion of CD4(+) T cells and limiting immune reconstitution. We used relevant animal and in vitro models to investigate the kinetics and possible underlying mechanism(s) of this process. In the lymphatic tissue of simian immunodeficiency virus (SIV)-infected rhesus macaques, we observed parallel increases in immune activation, transforming growth factor (TGF) beta 1-positive regulatory T (T(reg)) cells, and collagen type I deposition by 7 days after inoculation, consistent with the hypothesis that early immune activation elicits a countering T(reg) cell response associated with TGF beta 1 expression and collagen deposition. In support of this hypothesis and the possible role of fibrosis in viral pathogenesis, we show (1) spatial colocalization and temporal concordance in levels of TGF beta 1(+) T(reg) cells and collagen deposition; (2) TGF beta 1(+) inducible T(reg) cell stimulation of primary lymphatic tissue fibroblasts to produce collagen type I in vitro; and (3) high levels of immune activation, TGF beta 1(+) T(reg) cells, and collagen deposition in pathogenic SIV infection of macaques, in contrast to apathogenic SIV infection in sooty mangabeys in which levels of immune activation, TGF beta 1(+) T(reg) cells, and collagen deposition were low. We thus conclude that the response of TGF beta 1(+) T(reg) cells to immune activation in early SIV/HIV infection is a double-edged sword: TGF beta 1(+) T(reg) cells normally have a positive effect by limiting immunopathological and autoreactive immune responses, but they also have a negative effect by dampening the antiviral immune response and, as we show here, causing deleterious effects on CD4(+) T cell homeostasis by inducing collagen deposition in lymphatic tissues.

PD-1 is a regulator of virus-specific CD8+ T cell survival in HIV infection

Here, we report on the expression of programmed death (PD)-1 on human virus-specific CD8⁺ T cells and the effect of manipulating signaling through PD-1 on the survival, proliferation, and cytokine function of these cells. PD-1 expression was found to be low on naive CD8⁺ T cells and increased on memory CD8⁺ T cells according to antigen specificity. Memory CD8⁺ T cells specific for poorly controlled chronic persistent virus (HIV) more frequently expressed PD-1 than memory CD8⁺ T cells specific for well-controlled persistent virus (cytomegalovirus) or acute (vaccinia) viruses. PD-1 expression was independent of maturational markers on memory CD8⁺ T cells and was not directly associated with an inability to produce cytokines. Importantly, the level of PD-1 surface expression was the primary determinant of apoptosis sensitivity of virus-specific CD8⁺ T cells. Manipulation of PD-1 led to changes in the ability of the cells to survive and expand, which, over several days, affected the number of cells expressing cytokines. Therefore, PD-1 is a major regulator of apoptosis that can impact the frequency of antiviral T cells in chronic infections such as HIV, and could be manipulated to improve HIV-specific CD8⁺ T cell numbers, but possibly not all functions in vivo.

Premature Induction of an Immunosuppressive Regulatory T Cell Response during Acute Simian Immunodeficiency Virus Infection

Here we report the results of an investigation into the possibility that one mechanism responsible for the establishment of persistent human immunodeficiency virus infection is an early regulatory T (Treg) cell response that blunts virus-specific responses. Using the simian immunodeficiency virus (SIV)-infected rhesus macaque model, we show that, indeed, viral replication and immune activation in lymphatic tissue drive a premature immunosuppressive response, with dramatic increases in the frequencies of CD4+CD25+FOXP3+ Treg cells, transforming growth factor- beta 1+ cells, interleukin-10+ cells, and indoleamine 2,3-dioxygenase+CD3+ cells. When we compared SIV infection with rhesus cytomegalovirus (RhCMV) infection, we found that the frequency of Treg cells paralleled the magnitude of immune activation during both infections but that the magnitude of immune activation and of the Treg cell response were lower and peaked much later during RhCMV infection. Importantly, the frequency of Treg cells inversely correlated with the magnitude of the SIV-specific cytotoxic T lymphocyte response. We conclude that an early Treg cell response during acute SIV infection may contribute to viral persistence by prematurely limiting the antiviral immune response before infection is cleared.

HIV binding, penetration, and primary infection in human cervicovaginal tissue

We have developed human cervicovaginal organ culture systems to examine the initiating events in HIV transmission after exposure to various sources of HIV infectivity, including semen. Newly infected cells were detected in the cervical submucosa 3-4 days after exposure to a primary HIV isolate. At earlier times, extensive and stable binding occurred when cervical surfaces were exposed to virions or seminal cells. Cervical mucus provided some protection for the endocervical surface, by physically trapping virions and seminal cells. Confocal microscopy combined with 3D surface reconstruction revealed that virions could both bind to the external surface of the cervical epithelium and actually penetrate beneath the epithelial surface. In quantitative assays, pretreatment with a blocking antibody directed against beta1 integrin reduced HIV virion binding. Collectively, these results highlight a continuum of complex interactions that occurs when natural sources of HIV infectivity are deposited onto mucosal surfaces in the female reproductive tract.

A model system of oral HIV exposure, using human palatine tonsil, reveals extensive binding of HIV infectivity, with limited progression to primary infection

Oral exposure to human immunodeficiency virus (HIV) type 1 results in systemic infection, but many details surrounding virus transmission remain unresolved. We developed a mucosal model, using human palatine tonsil with intact external epithelium, to study events after oral exposure to HIV. When applied to the external epithelium, semen from an HIV-seropositive patient and cell-free virus both established HIV infection in individual tonsillar cells. However, clusters of infected tonsillar cells were detected where the epithelial surface was damaged. Investigation of the initial events in HIV transmission revealed extensive and stable binding of HIV virions and seminal cells to tonsil epithelium. In experiments modeling physiologically relevant events, the addition of seminal plasma resulted in enhanced virion binding to epithelial cells. These results indicate that, although extensive binding of HIV virions and seminal cells can be demonstrated at an exposed mucosal surface, there is only limited progression from binding to primary infection.

Functional genomic analysis of the response of HIV-1-infected lymphatic tissue to antiretroviral therapy

Highly active antiretroviral therapy (HAART) curtails human immunodeficiency virus type 1 (HIV-1) replication in lymphatic tissues and partially reverses the pathological damage associated with infection, but the genes that mediate these pathological and reparative processes remain largely unknown. To identify these genes, we used microarrays to profile gene expression in serial lymph node biopsy specimens obtained before and after treatment. We discovered approximately 200 treatment-responsive genes, many of them known mediators and moderators of immune activation and defenses, particularly innate defense genes, which, surprisingly, were expressed at all stages of HIV-1 infection. Most of the rest of the treatment-responsive genes we categorized as mediators of trafficking, reformation of active follicles, and tissue repair. We propose a model in which nearly counterbalanced functions of mediators and moderators of immune activation and defenses account for the slow dynamics of HIV-1 infection before treatment. This model suggests that there could be a role for anti-inflammatory agents, alone or in combination with HAART, in treating HIV-1 infection by tipping this balance to mitigate pathology.

Changes in plasma human immunodeficiency virus type 1 RNA associated with herpes simplex virus reactivation and suppression

In early trials of antiretroviral therapy, acyclovir was associated with increased survival by an unknown mechanism. The hypothesis that subclinical herpes simplex virus (HSV) reactivation was associated, in vivo, with increased plasma human immunodeficiency virus (HIV) RNA and suppression with a reduced plasma HIV RNA load was investigated. HSV cultures were performed daily on HSV-2-positive/HIV-positive patients, and plasma HIV-1 RNA loads were measured at regular intervals. A subset of patients prior to, during, and after HSV suppression with high-dose acyclovir was measured to determine whether HSV suppression was associated with a decrease in HIV replication. Most (25/27 HSV-2-positive/HIV-positive persons) reactivated HSV. Total HSV shedding rate was strongly correlated with plasma HIV-1 RNA load (R=0.54; P=.004), and the plasma HIV-1 RNA level at a given CD4 cell count was 48% lower when treated with acyclovir. These data indicate that frequent mucosal HSV reactivation influences HIV replication in vivo and daily HSV suppression may be important in the management of HSV-positive/HIV-positive persons.

The role of HSV in the transmission and progression of HIV

Herpes simplex virus (HSV) is a common co-infection in persons infected with human immunodeficiency virus type 1 (HIV-1). Chronic perianal ulceration from herpes simplex virus type 2 (HSV-2) was one of the first opportunisitc infections identified among patients with AIDS. Subsequent research has established that the natural history of HSV-2 is altered in co-infected persons as they experience more frequent clinical and subclinical reactivation of HSV than persons infected only with HSV-2. In addition, there are accumulating data to suggest a significant biological interaction between these two viruses that result in more efficient sexual transmission of HIV-1 and an increased rate of HIV replication during both clinical and subclinical HSV reactivation.

Treatment of primary human immunodeficiency virus type 1 infection with potent antiretroviral therapy reduces frequency of rapid progression to AIDS

Immunologic data supporting immediate antiretroviral therapy in primary human immunodeficiency virus type 1 (HIV-1) infection are emerging; however, clinical benefit has not been demonstrated. The clinical and virologic course of 47 patients who were enrolled from September 1993 through June 1996 and who were not initially treated with potent therapy was compared with the course of 20 patients who immediately began therapy with zidovudine, lamivudine, and indinavir. Demographic and baseline laboratory data were comparable. During 78 weeks of follow-up, the early-treatment cohort showed a reduced frequency of opportunistic infections (5% vs. 21.3%; relative risk, 0.11; P=.02), less frequent progression to AIDS (13% vs. 0%), and significantly less frequent nonopportunistic mucocutaneous disorders and respiratory infections (P<.01). Plasma HIV-1 RNA levels were <50 copies/mL in all patients who continued therapy; however, after 9--12 months, HIV-1 remained detectable in latently infected CD4(+) T cells and in lymph node mononuclear cells. Combination antiretroviral therapy during primary HIV-1 infection demonstrated a decreased frequency of minor opportunistic infections, mucocutaneous disorders, and respiratory infections and reduced progression to AIDS.

Productive infection of T cells in lymphoid tissues during primary and early human immunodeficiency virus infection

Current models suggest that during human immunodeficiency virus type 1 (HIV-1) transmission virions are selected that use the CCR5 chemokine receptor on macrophages and/or dendritic cells. A gradual evolution to CXCR4 chemokine receptor use causes a shift in the proportion of productively infected cells to the CD4 cell population. Productively infected cells during acute and early infection in lymphoid tissue were assessed, as well as the impact of productive infection on the T cell population in 21 persons who had biopsies performed on days 2-280 after symptoms of acute HIV-1 seroconversion. Even in the earliest stages of infection, most productively infected cells were T lymphocytes. There were sufficient infected cells in lymphoid tissue (LT) to account for virus production and virus load in plasma. Despite the relatively high frequency of productively infected cells in LT, the impact on the size of the T cell population in LT at this stage was minor.

Mucosal shedding of human herpesvirus 8 in men

BACKGROUND

Epidemiologic studies suggest that human herpesvirus 8 (HHV-8) is sexually transmitted among men who have sex with men; however, the mode of transmission is unclear.

METHODS

To evaluate the patterns of shedding of HHV-8, we obtained mucosal-secretion samples from a cohort of HHV-8-seropositive men who had sex with men and had no clinical evidence of Kaposi's sarcoma. Quantitative polymerase-chain-reaction (PCR) assays, in situ PCR assays, and in situ RNA hybridization were used to identify potential sources of infectious HHV-8.

RESULTS

We detected HHV-8 in at least one mucosal sample from 30 of 50 men who were seropositive for HHV-8 (60 percent). Overall, HHV-8 was detected in 30 percent of oropharyngeal samples, as compared with 1 percent of anal and genital samples (P<0.001). In 39 percent of the HHV-8-seropositive men, HHV-8 was detected in saliva on more than 35 percent of the consecutive days on which samples were obtained. The median log titer of HHV-8 from the oral cavity was approximately 2.5 times as high as the titer at all other sites. In situ hybridization studies indicated that HHV-8 DNA and messenger RNA were present in oral epithelial cells. Among 92 men who had sex with men and who were seronegative for the human immunodeficiency virus (HIV), a history of sex with a partner who had Kaposi's sarcoma, deep kissing with an HIV-positive partner, and the use of amyl nitrite capsules ("poppers") or inhaled nitrites were independent risk factors for infection with HHV-8.

CONCLUSIONS

Oral exposure to infectious saliva is a potential risk factor for the acquisition of HHV-8 among men who have sex with men. Hence, currently recommended safer sex practices may not protect against HHV-8 infection.

Rapid accumulation of human immunodeficiency virus (HIV) in lymphatic tissue reservoirs during acute and early HIV infection: implications for timing of antiretroviral therapy

The follicular dendritic cell network (FDC) in lymphoid tissues (LTs) is the major site of human immunodeficiency virus (HIV) storage in presymptomatic and late stages of disease. However, little is known about the rate of virus accumulation during the acute and early stages. In situ hybridization and quantitative image analysis were used to determine the amount of virus bound to the FDC network during the first year of infection. The FDC pool was already >7.0 log10 copies of HIV RNA/g LT in the first year, and 2 patients biopsied within 2-4 days of symptom onset had 7.3 and 8.2 log10 copies of HIV RNA/g LT, respectively. There was no correlation between duration of infection and accumulation of HIV into the FDC network. These data suggest that a large pool of infectious virus is established soon after infection and that initiation of antiretroviral therapy when symptoms of primary HIV infection are recognized is unlikely to prevent substantial accumulation of virus in the FDC network.

Effect of combination antiretroviral therapy on T-cell immunity in acute human immunodeficiency virus type 1 infection

T-cell responses were evaluated prospectively in 41 patients with acute human immunodeficiency virus type 1 (HIV-1) infection (30 untreated and 11 receiving zidovudine, lamivudine, and indinavir) and in 38 uninfected adults. By 6-12 months, treated patients had significantly greater median Candida and tetanus lymphoproliferative responses (stimulation index [SI], 76 and 55, respectively) than did untreated patients (SI, 7 and 6, P=.02 and.001, respectively), and the responses of treated patients surpassed those of uninfected adults (SI, 19 and 32, P= .002 and .101, respectively). Unlike the patients in the untreated group, the patients in the treated group mounted a 6-fold increased HIV-1 p24 response (SI increase, 1.0 to 5.7, P= .01) within 3 months. HIV-1-specific cytotoxicity remained detectable in most treated patients. Thus, combination therapy administered within 3-4 months of infection was associated with improved T-cell memory responses that were distinct from those of untreated patients. The amplified HIV-1-specific T-cell responses may help maintain cytotoxic activities.

Frequency of symptomatic and asymptomatic herpes simplex virus type 2 reactivations among human immunodeficiency virus-infected men

Herpes simplex virus (HSV) infection is common in persons coinfected with human immunodeficiency virus (HIV). In a prospective study, daily viral cultures of the mouth, genitals, and rectum were collected from 68 HIV-positive and 13 HIV-negative men who have sex with men. Subjects completed a median of 57 days of follow-up. Anogenital HSV-2 cultures were positive on 405 (9.7%) of 4167 days for HIV-positive men and on 24 (3.1%) of 766 days for HIV-negative men. Most reactivations were perirectal and subclinical. Risk factors for increased HSV-2 shedding among HIV-positive men were low CD4 cell count (odds ratio, 2.5; 95% confidence interval, 1.2-5.4) and antibodies to both HSV-1 and HSV-2 versus HSV-2 only (odds ratio, 1.9; 95% confidence interval, 1.0-3.7). Three isolates obtained from 3 separate subjects were resistant to acyclovir. Thus, subclinical HSV-2 reactivation is an important opportunistic infection in persons with HIV infection. Further studies are necessaryto determine the impact of subclinical HSV-2 reactivation on the natural history of HIV infection.

Frequent recovery of HIV-1 from genital herpes simplex virus lesions in HIV-1-infected men

CONTEXT

Genital ulcer disease has been epidemiologically linked as a risk factor in the transmission of the human immunodeficiency virus 1 (HIV-1). While herpes simplex virus 2 (HSV-2) is the most common cause of genital ulcers, no study has systematically evaluated the frequency or titer of HIV-1 virus in HSV-2 lesions.

OBJECTIVE

To compare lesional HIV-1 RNA levels during and after genital HSV-2 reactivation and to evaluate the frequency, titer, and duration of HIV-1 RNA shedding in lesions due to HSV-2.

DESIGN

Convenience sample.

SETTING

Sexually transmitted disease research clinic at the University of Washington, Seattle.

PATIENTS

Twelve HIV-infected men with a history of symptomatic HSV-2 infection who underwent daily sampling of genital lesions for HIV-1 RNA by polymerase chain reaction assay and HSV-2 by culture.

MAIN OUTCOME MEASURE

Detection of lesional HIV RNA and HSV-2.

RESULTS

HIV-1 RNA was detected from lesional swabs in 25 of 26 consecutively studied HSV-2 episodes and on 67% of days in which genital lesions were noted. The HIV-1 RNA titers in lesional swabs exceeded 10000 copies/mL of swab sample in 75% of samples (range, 2.2-3.2 x 10(5) copies/mL of swab sample). HIV-1 RNA in genital lesion swabs was seen in persons with high and low titers of plasma HIV-1 RNA and was not associated with plasma HIV-1 RNA levels.

CONCLUSIONS

HIV-1 virions can consistently be detected in genital ulcers caused by HSV-2, which suggests that genital herpes infection likely increases the efficiency of the sexual transmission of HIV-1.

Evolutionary pattern of human immunodeficiency virus (HIV) replication and distribution in lymph nodes following primary infection: implications for antiviral therapy

Evolutionary patterns of virus replication and distribution in lymphoid tissue during the early phases of HIV infection have not been delineated. Lymph node (LN) biopsies were excised from patients at different times after the estimated time of primary infection. Within 3 months of the acute viral syndrome, HIV was mostly present in individual virus-expressing cells in LNs; trapping of virions in the follicular dendritic cell (FDC) network was minimal or absent, but was the predominant form of HIV detected in LNs of subjects with chronic infection, either recent (4-20 months after primary infection) or long-term (>2-3 years after primary infection). Plasma viremia was significantly higher in patients during the first 3 months than in those recently infected; however, there were no significant differences in the number of virus-expressing cells per square millimeter of LN tissue in these two groups. Numbers of virus-expressing cells in lymphoid tissue were significantly lower in the subjects with long-term infection than in the other two groups. Therefore, during the transition from primary to chronic HIV infection, the level of HIV replication in lymphoid tissue remains elevated despite the fact that viremia is significantly downregulated. These findings have implications for therapeutic strategies in primary HIV infection and in recent seroconvertors.

Famciclovir for the suppression of symptomatic and asymptomatic herpes simplex virus reactivation in HIV-infected persons. A double-blind, placebo-controlled trial

BACKGROUND

Herpes simplex virus (HSV) infection is one of the most common opportunistic infections in HIV-infected persons. However, most documentation of the effectiveness of antiviral therapy in reducing HSV reactivation is anecdotal.

OBJECTIVE

To evaluate the quantitative effect of antiviral therapy on the frequency of HSV reactivation in HIV-infected persons.

DESIGN

Double-blind, placebo-controlled, crossover trial.

SETTING

Research clinic at a university hospital.

PATIENTS

48 persons (45 men and 3 women) who were HIV positive and HSV seropositive.

INTERVENTION

Patients were randomly assigned to receive famciclovir, 500 mg orally twice daily, or placebo for 8 weeks. They then crossed over to receive the other regimen after a 1-week washout period.

MEASUREMENTS

Patients obtained daily cultures of their perirectal, urethral, oral, and genital areas and kept dairy records of signs and symptoms of genital and oral-labial herpes.

RESULTS

The median CD4 cell count at study entry was 384 cells/mm3. In the intention-to-treat analysis of the first study period, HSV was isolated on 122 of 1114 (11%) placebo days compared with 9 of 1071 (1%) famciclovir days (relative risk, 0.15; P < 0.001). For patients who completed the crossover, the median difference in days with symptoms between placebo and famciclovir was 13.8% of days and the median difference in days on which HSV was isolated was 5.4% of days (P < 0.001 for both). Percentage of days with HSV-2 shedding was reduced from 9.7% to 1.3%. Breakthrough reactivations that occurred while patients were receiving famciclovir were infrequent, short, and often asymptomatic, HSV-2 isolates from these reactivations were susceptible to penciclovir in vitro.

CONCLUSIONS

Antiviral chemotherapy with famciclovir results in clinically and statistically significant reductions in the symptoms associated with HSV infection and the symptomatic and asymptomatic shedding of HSV among HIV-positive persons.

Cytotoxic-T-cell responses, viral load, and disease progression in early human immunodeficiency virus type 1 infection

BACKGROUND

Early in human immunodeficiency virus type 1 (HIV-1) infection there is a decline in viral replication that has been attributed to host immunity, but the components of this response, particularly the ability of cytotoxic T lymphocytes to control viral burden and influence the outcome of disease, are poorly understood.

METHODS

We prospectively studied 33 patients with primary HIV-1 infection for HIV-specific activated cytotoxic T lymphocytes and memory cytotoxic T lymphocytes and compared these lymphocyte responses with changes in viral load and clinical status over the subsequent 18 to 24 months.

RESULTS

Soon after infection, activated HIV-specific cytotoxic T lymphocytes, mediated primarily by CD8+ cells, were detected in 17 of 23 patients (74 percent). Memory cytotoxic T lymphocytes were found in 6 of 6 patients tested (100 percent) during the first three months of infection and in 17 of 21 patients (81 percent) tested during the first six months. The frequencies of memory cytotoxic T lymphocytes varied markedly over time, but overall they declined over the first 6 to 8 months and then stabilized over the next 12 to 18 months. The patients with higher frequencies of Env-specific memory cytotoxic T lymphocytes had a median level of plasma HIV-1 RNA about one third that of the patients with lower frequencies, (median number of RNA copies per milliliter, 22,000 vs. 62,000; P=0.006). Patients with low frequencies of Env-specific memory cytotoxic T lymphocytes (or none) in early infection had a more rapid decline to less than 300 CD4+ cells per cubic millimeter (P = 0.05).

CONCLUSIONS

In early HIV-1 infection, the induction of memory cytotoxic T lymphocytes, particularly those specific for Env, helps control viral replication and is associated with slower declines in CD4+ cell counts. Host cytolytic effector responses appear to delay the progression of HIV-1 disease.

A randomized, double-blind, placebo-controlled trial of cidofovir gel for the treatment of acyclovir-unresponsive mucocutaneous herpes simplex virus infection in patients with AIDS

The safety and efficacy of cidofovir gel for treatment of acyclovir-unresponsive herpes simplex virus infections in AIDS patients was evaluated in a randomized, double-blind, multicenter trial. Cidofovir (0.3% or 1%) or placebo gel was applied once daily for 5 days. Ten of 20 cidofovir-treated and none of 10 placebo-treated patients had complete healing or >50% decreased area (P = .008); 30% of cidofovir-treated patients versus 0 placebo recipients had complete healing (P = .031). Viral shedding ceased in 13 (87%) of 15 cidofovir-treated and 0 of 9 placebo-treated patients (P = .00004). For cidofovir-treated patients, median time to complete or good response was 21 days, and median time to negative viral culture was 2 days (P = .025, P = .0001, respectively). Median lesion area decreases were 58% for cidofovir-treated versus 0 for placebo-treated patients (P = .005), and mean pain score changes were -1.84 versus -0.34 (P = .042). Application site reactions occurred in 25% of cidofovir-treated and 20% of placebo-treated patients; none was dose-limiting. Cidofovir therapy provided significant benefits in lesion healing, virologic effect, and pain reduction.

Primary HIV infection. Early diagnosis and treatment are critical to outcome

It is now apparent that early identification of primary HIV infection is important, because events occurring in early disease may predict how fast a patient progresses to AIDS. However, as Dr Schacker points out, diagnosis is not easy at this stage. This article describes clinical features and laboratory tests to help primary care physicians make a timely diagnosis and discusses current recommendations for therapy.

The relationship between tumor necrosis factor and human immunodeficiency virus gene expression in lymphoid tissue

In tissue culture models of chronic human immunodeficiency virus type 1 (HIV-1) infection, cytokines such as tumor necrosis factor alpha (TNF-alpha) activate viral gene expression. We sought evidence that TNF-alpha might similarly regulate viral gene expression in vivo in the major lymphoid tissue (LT) reservoir. We used in situ hybridization, quantitative image analysis, and double-label techniques to compare cytokine and HIV-1 RNA levels in sections of tonsil and lymph node tissues obtained from individuals in early and later stages of HIV-1 infection. The levels of TNF-alpha gene expression in LT from HIV-1-infected an uninfected individuals were indistinguishable, and we found no correlation between TNF-alpha gene expression in LT and the level of HIV-1 gene expression in LT. There is thus little evidence that in vivo TNF-alpha significantly influences HIV production in LT.

Herpes simplex virus seropositivity and reactivation at delivery among pregnant women infected with human immunodeficiency virus-1

OBJECTIVE

Our purpose was to determine whether pregnant women infected with human immunodeficiency virus-1 have an increased risk of herpes simplex virus-2 seropositivity and herpes simplex virus reactivation at delivery.

STUDY DESIGN

Sixty women infected with human immunodeficiency virus and 8408 other patients who were delivered at the University of Washington between 1989 and 1995 had herpes simplex virus serologic determinations at delivery. Genital herpes simplex virus cultures were obtained for 48 (80%) of the human immunodeficiency virus-infected women and 5567 (66%) of the controls. Logistic regression was used to adjust for possible confounding factors.

RESULTS

Forty-five (75%) of human immunodeficiency virus-infected women and 2709 (32%) controls were seropositive for herpes simplex virus-2 (p < 0.0001). Eight percent of human immunodeficiency virus-infected women and 2% of controls had herpes simplex virus reactivation in labor (p < 0.05).

CONCLUSIONS

Infection with herpes simplex virus-2 is common among pregnant women infected with human immunodeficiency virus. Herpes simplex virus reactivation complicates labor in this group more often than in other obstetric patients. The role of herpes simplex virus in perinatal human immunodeficiency virus transmission warrants further study.

Divergent patterns of progression to AIDS after infection from the same source: human immunodeficiency virus type 1 evolution and antiviral responses

The rate of progression to AIDS in human immunodeficiency virus type 1 (HIV-1)-infected individuals is determined by a complex series of interactions between the host and virus. Here we evaluate virologic properties and host responses in two men near-simultaneously infected with HIV-1 from the same sexual partner--one individual progressed to AIDS in less than 2 years, and the other remains asymptomatic 3 years postinfection. Distinct neutralizing antibody and cellular immune responses were evident, with the slower progressor exhibiting generally stronger and broader responses, except for cytotoxic T-lymphocyte responses early in infection. Virtually identical, homogeneous virus populations were found in both patients in the first sample obtained; however, a second unrelated HIV-1 virus population was also found in the fast progressor. Whether the second population emanated from an additional source of infection or the two were transmitted from the original source could not be determined. The virus population in the slower progressor turned over and diversified rapidly, whereas both virus populations in the rapid progressor evolved at a much slower rate. In addition, the character of mutational changes underlying these diversities appeared to be distinct, with a bias for diversifying selection developing in the slower progressor and a reciprocal bias towards purifying selection maintained in both populations in the fast progressor. Thus, the rapid evolution that is a hallmark of HIV replication may be a reflection of strong host resistance against emerging virus variants and a longer period of asymptomatic infection. Furthermore, rapid progression was not linked to a collapse of any appreciable immune response following attainment of some threshold of antigenic diversity but rather to a failure to drive this diversification and a condition of relatively unimpeded expansion of variants with optimized replicative capacity within the host.

The qualitative nature of the primary immune response to HIV infection is a prognosticator of disease progression independent of the initial level of plasma viremia

Following infection of the host with a virus, the delicate balance between virus replication/spread and the immune response to the virus determines the outcome of infection, i.e., persistence versus elimination of the virus. It is unclear, however, what relative roles immunologic and virologic factors play during primary viral infection in determining the subsequent clinical outcome. By studying a cohort of subjects with primary HIV infection, it has been demonstrated that qualitative differences in the primary immune response to HIV, but not quantitative differences in the initial levels of viremia are associated with different clinical outcomes.

Clinical and epidemiologic features of primary HIV infection

BACKGROUND

The acute clinical events surrounding the acquisition of human immunodeficiency virus (HIV) have not been well characterized.

OBJECTIVE

To further define the clinical and epidemiologic presentation of primary HIV infection.

DESIGN

Descriptive cohort study.

SETTING

University research clinic.

PATIENTS

46 adults (43 men and 3 women) with primary HIV infection who enrolled in the study a median of 51 days after HIV seroconversion.

MEASUREMENTS

Documentation of recent HIV seroconversion. Standardized collection of demographic characteristics and sexual contact history, results of tests for HIV RNA, HIV culture, and T-cell subsets.

RESULTS

41 of 46 patients (89%) developed an acute retroviral syndrome. Primary HIV infection was infrequently diagnosed at the initial medical encounter, even in persons enrolled in routine HIV screening programs. Median numbers of sexual partners 6 months and 1 month before acquisition of HIV were three and one, respectively; 21 patients (46%) reported having had only one partner in the month before seroconversion. Of the 12 patients who could identify the precise date of and activity leading to seroconversion, 4 reported having only oral-genital contact.

CONCLUSIONS

Primary HIV infection causes a recognizable clinical syndrome that is often underdiagnosed, even in persons enrolled in a program of routine surveillance for HIV infection. Frequency of sexual contact and overall numbers of sexual partners in this group of homosexual men who acquired HIV were markedly lower than those seen a decade ago. Acquisition of HIV does occur, even in persons with relatively few sexual partners. Increased attention to oral-genital contact as a means of acquiring HIV appears to be warranted.

Phase I study of high-dose, intravenous rsCD4 in subjects with advanced HIV-1 infection

In vitro, recombinant soluble CD4 (rsCD4) attaches to and inactivates human immunodeficiency virus (HIV). To determine if prolonged therapy with high-dose intravenous rsCD4 provides an in vivo benefit, we gave three HIV-1-infected patients with AIDS, whose isolates were susceptible in vitro to rsCD4, 10 mg/kg of rsCD4 for 4 weeks, 5 mg/kg for 4 weeks, and 1 mg/kg for 2 weeks. Single-dose pharmacokinetic studies performed prior to this showed transient in vivo decreases of HIV-1 plasma viremia in all three subjects. Surrogate markers of HIV activity, clinical status, HIV-1 p24 antigen, plasma HIV-1 titers, and peripheral blood mononuclear cell (PBMC) intracellular titers of virus were measured at entry, and every other week after onset of therapy. All subjects demonstrated rsCD4 concentration-dependent reduction in plasma viremia, with two subjects having complete neutralization of cell-free virus. The third subject's isolate was relatively resistant to the in vivo effects of rsCD4 and only partial reduction in plasma virus titers was obtained, even at the highest dose of 10 mg/kg. There was no change in the PBMC intracellular viral titer or surrogate markers of HIV-1 activity (including CD4 cell count and beta 2-microglobulin). There was subjective improvement in clinical symptoms, and all subjects gained weight with the highest doses of rsCD4. rsCD4 exhibited linear pharmacokinetics over the dose range studied. We conclude that high-dose intravenous rsCD4 can be safely given for up to 10 weeks and that it has a stable pharmacokinetic profile.(ABSTRACT TRUNCATED AT 250 WORDS)

Human herpesvirus 6 DNA in blood cells of human immunodeficiency virus-infected men: correlation of high levels with high CD4 cell counts

The relationship between human herpesvirus 6 (HHV-6) and the progression of human immunodeficiency virus type 1 (HIV-1) infection to AIDS was evaluated using the polymerase chain reaction to quantitate HHV-6 genome equivalents in peripheral blood mononuclear cells (PBMC) and saliva of 32 HIV-1-seropositive men. Unlike other herpesviruses, HHV-6 was found with higher frequency and in higher copy numbers of HIV-infected men with high rather than low CD4 cell counts. Among subjects with > 400 CD4 cells/mL, 100% had detectable HHV-6 genomes in PBMC compared with 57.9% of subjects with < 400 CD4 cells/mL (P < .05). There was no significant correlation between HHV-6 antibody titer or number of amplifiable copies of HHV-6 DNA in saliva and stage of HIV disease or CD4 cell number.

The effects of high-dose recombinant soluble CD4 on human immunodeficiency virus type 1 viremia

In vitro, low-passage clinical human immunodeficiency virus type 1 (HIV-1) isolates require up to 1000 times greater serum levels of recombinant soluble CD4 (rsCD4) than have ever been given. To determine if sufficient serum levels of rsCD4 provide in vivo inhibition of HIV-1, 4 HIV-1 plasma-viremic subjects were given single-dose boluses of 2, 4, 6, 8, and 10 mg/kg intravenous rsCD4. Plasma HIV-1 cultures were done after infusion. Three subjects demonstrated a dose-dependent reduction in plasma HIV-1 viremia. The inhibitory effect of rsCD4 on plasma HIV-1 viremia was associated with the in vitro ID90-95 of the isolate, not the ID50. These data demonstrate that extremely high doses of rsCD4 inactivate cell-free HIV-1 in vivo and suggest that high doses of rsCD4 may have some short-term therapeutic utility, such as with accidental or occupational HIV-1 exposure.

Topical treatment of infection with acyclovir-resistant mucocutaneous herpes simplex virus with the ribonucleotide reductase inhibitor 348U87 in combination with acyclovir

The thiocarbonohydrazone 348U87 inactivates herpes simplex virus ribonucleotide reductase and potentiates the activity of acyclovir against wild-type and acyclovir-resistant strains of herpes simplex virus. We treated 10 human immunodeficiency virus-infected patients with acyclovir-resistant anogenital herpes simplex virus infection with a topical preparation of 348U87 (3%) in combination with acyclovir (5%) in an open-labelled study. Transient improvement with combination therapy occurred frequently; however, target lesions reepithelialized completely in only 1 of 10 patients. Termination of study drug therapy was most often due to cessation of therapeutic effect before complete resolution of lesions. As currently formulated, topical 348U87 offers little therapeutic benefit for this indication.

Potential for combined therapy with 348U87, a ribonucleotide reductase inhibitor, and acyclovir as treatment for acyclovir-resistant herpes simplex virus infection

Inhibitors of the ribonucleotide reductase of herpes simplex viruses (HSV) potentiate the activity of acyclovir in vitro and in animal studies. In addition, the combination of the ribonucleotide reductase inhibitor 348U87 and acyclovir has synergistic therapeutic effects against infections in mice due to thymidine kinase-deficient, thymidine kinase-altered, and DNA polymerase mutants of HSV. We performed a pilot study of topical combination therapy with 348U87 (3%) and acyclovir (5%) cream for acyclovir-resistant, anogenital HSV infections in ten human immunodeficiency virus (HIV)-infected patients. Our results, with lack of complete reepitheliazation of lesions in all patients and poor virologic response, suggest that this therapy is unlikely to be useful for this indication.