HIV serodiscordant sex partners and the prevalence of human herpesvirus 8 infection among HIV negative men who have sex with men: baseline data from the EXPLORE Study

Today's Kaposi sarcoma is not the same as it was 40 years ago, or is it?

This review will provide an overview of the notion that Kaposi sarcoma (KS) is a disease that manifests under diverse and divergent circumstances. We begin with a historical introduction of KS and KS-associated herpesvirus (KSHV), highlight the diversity of clinical presentations of KS, summarize what we know about the cell of origin for this tumor, explore KSHV viral load as a potential biomarker for acute KSHV infections and KS-associated complications, and discuss immune modulators that impact KSHV infection, KSHV persistence, and KS disease.

Kaposi's Sarcoma-Associated Herpesvirus, the Etiological Agent of All Epidemiological Forms of Kaposi's Sarcoma

Simple Summary

Kaposi’s sarcoma-associated herpesvirus (KSHV) is one of the seven oncogenic viruses currently recognized by the International Agency for Research on Cancer. Its presence for Kaposi’s sarcoma development is essential and knowledge on the oncogenic process has increased since its discovery in 1994. However, some uncertainties remain to be clarified, in particular on the exact routes of transmission and disparities in KSHV seroprevalence and the prevalence of Kaposi’s sarcoma worldwide. Here, we summarized the current data on the KSHV viral particle’s structure, its genome, the replication, its seroprevalence, the viral diversity and the lytic and latent oncogenesis proteins involved in Kaposi’s sarcoma. Lastly, we reported the environmental, immunological and viral factors possibly associated with KSHV transmission that could also play a role in the development of Kaposi’s sarcoma.

Abstract

Kaposi’s sarcoma-associated herpesvirus (KSHV), also called human herpesvirus 8 (HHV-8), is an oncogenic virus belonging to the Herpesviridae family. The viral particle is composed of a double-stranded DNA harboring 90 open reading frames, incorporated in an icosahedral capsid and enveloped. The viral cycle is divided in the following two states: a short lytic phase, and a latency phase that leads to a persistent infection in target cells and the expression of a small number of genes, including LANA-1, v-FLIP and v-cyclin. The seroprevalence and risk factors of infection differ around the world, and saliva seems to play a major role in viral transmission. KSHV is found in all epidemiological forms of Kaposi’s sarcoma including classic, endemic, iatrogenic, epidemic and non-epidemic forms. In a Kaposi’s sarcoma lesion, KSHV is mainly in a latent state; however, a small proportion of viral particles (<5%) are in a replicative state and are reported to be potentially involved in the proliferation of neighboring cells, suggesting they have crucial roles in the process of tumorigenesis. KSHV encodes oncogenic proteins (LANA-1, v-FLIP, v-cyclin, v-GPCR, v-IL6, v-CCL, v-MIP, v-IRF, etc.) that can modulate cellular pathways in order to induce the characteristics found in all cancer, including the inhibition of apoptosis, cells’ proliferation stimulation, angiogenesis, inflammation and immune escape, and, therefore, are involved in the development of Kaposi’s sarcoma.

Poppers, by Inducing HHV-8 Virion Production, Can Act as a Promoter for HHV-8 Transmission in Men Who Have Sex With Men

Environmental factors were reported to increase the risk of human herpesvirus 8 (HHV-8) transmission. In a population of men who have sex with men (MSM), we found evidence that chemsex was associated with human herpesvirus 8 seropositivity in vivo and that poppers induced HHV-8 virion production in vitro. Our finding may explain the higher HHV-8 transmission in MSM.

Pathological Features of Kaposi's Sarcoma-Associated Herpesvirus Infection

Kaposi's sarcoma-associated herpesvirus (KSHV, human herpesvirus 8, or HHV-8) was firstly discovered in Kaposi's sarcoma tissue derived from patients with acquired immune deficiency syndrome. KSHV infection is associated with malignancies and certain inflammatory conditions. In addition to Kaposi's sarcoma, KSHV has been detected in primary effusion lymphoma, KSHV-associated lymphoma, and some cases of multicentric Castleman disease (MCD). Recently, KSHV inflammatory cytokine syndrome (KICS) was also defined as a KSHV-associated disease. In KSHV-associated malignancies, such as Kaposi's sarcoma and lymphoma, KSHV latently infects almost all tumor cells, and lytic proteins are rarely expressed. A high titer of KSHV is detected in the sera of patients with MCD and KICS, and the expression of lytic proteins such as ORF50, vIL-6, and vMIP-I and vMIP-II is frequently observed in the lesions of patients with these diseases. Immunohistochemistry of LANA-1 is an important diagnostic tool for KSHV infection. However, much of the pathogenesis of KSHV remains to be elucidated, especially regarding oncogenesis. Some viral proteins have been shown to have transforming activity in mammalian cells; however, these proteins are not expressed in latently KSHV-infected cells. KSHV encodes homologs of cellular proteins in its genome such as cyclin D, G-protein coupled protein, interleukin-6, and macrophage inflammatory protein-1 and -2. Molecular mimicry by these viral proteins may contribute to the establishment of microenvironments suitable for tumor growth. In this review, the virus pathogenesis is discussed based on pathological and experimental findings and clinical aspects.

HIV-associated Kaposi sarcoma and related diseases

: The search for the etiologic agent for Kaposi sarcoma led to the discovery of Kaposi sarcoma-associated herpesvirus (KSHV) in 1994. KSHV, also called human herpesvirus-8, has since been shown to be the etiologic agent for several other tumors and diseases, including primary effusion lymphoma (PEL), an extracavitary variant of PEL, KSHV-associated diffuse large B-cell lymphoma, a form of multicentric Castleman disease, and KSHV inflammatory cytokine syndrome. KSHV encodes several genes that interfere with innate and specific immunity, thwart apoptosis, enhance cell proliferation and cytokine production, and promote angiogenesis, and these play important roles in disease pathogenesis. HIV is an important cofactor in Kaposi sarcoma pathogenesis, and widespread use of antiretroviral therapy has reduced Kaposi sarcoma incidence. However, Kaposi sarcoma remains the second most frequent tumor arising in HIV-infected patients in the United States and is particularly common in sub-Saharan Africa. KSHV prevalence varies substantially in different populations. KSHV is secreted in saliva, and public health measures to reduce its spread may help reduce the incidence of KSHV-associated diseases. Although there have been advances in the treatment of Kaposi sarcoma, KSHV-multicentric Castleman disease, and PEL, improved therapies are needed, especially those that are appropriate for Kaposi sarcoma in resource-poor regions.

Kaposi's sarcoma: etiology and pathogenesis, inducing factors, causal associations, and treatments: facts and controversies

Kaposi's sarcoma (KS), an angioproliferative disorder, has a viral etiology and a multifactorial pathogenesis hinged on an immune dysfunction. The disease is multifocal, with a course ranging from indolent, with only skin manifestations to fulminant, with extensive visceral involvement. In the current view, all forms of KS have a common etiology in human herpesvirus (HHV)-8 infection, and the differences among them are due to the involvement of various cofactors. In fact, HHV-8 infection can be considered a necessary but not sufficient condition for the development of KS, because further factors (genetic, immunologic, and environmental) are required. The role of cofactors can be attributed to their ability to interact with HHV-8, to affect the immune system, or to act as vasoactive agents. In this contribution, a survey of the current state of knowledge on many and various factors involved in KS pathogenesis is carried out, in particular by highlighting the facts and controversies about the role of some drugs (quinine analogues and angiotensin-converting enzyme inhibitors) in the onset of the disease. Based on these assessments, it is possible to hypothesize that the role of cofactors in KS pathogenesis can move toward an effect either favoring or inhibiting the onset of the disease, depending on the presence of other agents modulating the pathogenesis itself, such as genetic predisposition, environmental factors, drug intake, or lymph flow disorders. It is possible that the same agents may act as either stimulating or inhibiting cofactors according to the patient’s genetic background and variable interactions.

Treatment guidelines for each form of KS are outlined, because a unique standard therapy for all of them cannot be considered due to KS heterogeneity. In most cases, therapeutic options, both local and systemic, should be tailored to the patient’s peculiar clinical conditions.

Quantitative determinations of anti-Kaposi sarcoma-associated herpesvirus antibody levels in men who have sex with men

Infection with Kaposi sarcoma-associated herpesvirus (KSHV; also called human herpesvirus-8) is common among men who have sex with men (MSM). Here, quantitative anti-KSHV antibody levels were measured using luciferase immunoprecipitation systems (LIPS) in an MSM cohort with and without HIV from the NIH Clinical Center. Antibodies were detected using a mixture of 4 KSHV antigens in the MSM cohort and in Kaposi sarcoma (KS) patients. Along with HIV status, these results were compared with K8.1 and ORF73 ELISA, PCR virus detection, and additional LIPS testing. LIPS revealed that 25% (76/307) of the MSM cohort were KSHV seropositive, including 59 HIV+ and 17 HIV- subjects. The anti-KSHV antibody levels detected by LIPS were not statistically different between the KSHV+/HIV+ and KSHV+/HIV- subgroups but were lower than the KS patients (P < 0.0001). ELISA analysis of the MSM cohort detected a 35.5% frequency of KSHV infection and showed agreement with 81% of the samples evaluated by LIPS. Further LIPS testing with v-cyclin, a second ORF73 fragment and ORF38 reconciled some of the differences observed between LIPS and the ELISA immunoassays, and the revised LIPS seroprevalence in the MSM cohort was increased to 31%. Additional quantitative antibody analysis demonstrated statistically lower KSHV antibody levels in MSM compared to KS patients, but no difference was found between KSHV infected with and without HIV coinfection. These findings also suggest that antibodies against v-cyclin and ORF38 are useful for identifying patients with asymptomatic KSHV infection.

Prevalence and correlates of Kaposi's sarcoma-associated herpesvirus infection in a sample of men who have sex with men in eastern China

This study aimed to determine the seroprevalence of Kaposi's sarcoma-associated herpesvirus (KSHV) and related factors in men who have sex with men (MSM) in China. A total of 208 subjects were recruited from eastern China from 2008 to 2009. Plasma samples were collected and screened for KSHV, HIV and syphilis. Overall, KSHV seroprevalence was 32·7% in the subjects. About 92·7% of subjects reported having ever had anal sex with a man, of whom 67·8% had receptive anal sex and 77·9% had insertive anal sex. About 93·1% of the study participants reported having had oral sex with a man, of whom 76·0% had receptive oral sex and 56·7% had insertive oral sex. KSHV seropositivity was independently associated with receptive anal sex [odds ratio (OR) 2·68, 95% confidence interval (CI) 1·15–6·23], syphilis (OR 3·25, 95% CI 1·56–6·76) and HSV-2 infection (OR 2·40, 95% CI 1·09–5·26). KSHV infection is highly prevalent and is probably sexually transmitted among MSM in eastern China.

Meeting the challenge of hematologic malignancies in sub-Saharan Africa

Cancer is a leading cause of death and disability in sub-Saharan Africa and will eclipse infectious diseases within the next several decades if current trends continue. Hematologic malignancies, including non-Hodgkin lymphoma, leukemia, Hodgkin lymphoma, and multiple myeloma, account for nearly 10% of the overall cancer burden in the region, and the incidence of non-Hodgkin lymphoma and Hodgkin lymphoma is rapidly increasing as a result of HIV. Despite an increasing burden, mechanisms for diagnosing, treating, and palliating malignant hematologic disorders are inadequate. In this review, we describe the scope of the problem, including the impact of endemic infections, such as HIV, Epstein-Barr virus, malaria, and Kaposi sarcoma-associated herpesvirus. We additionally describe current limitations in hematopathology, chemotherapy, radiotherapy, hematopoietic stem cell transplantation, and supportive care and palliation. We review contemporary treatment and outcomes of hematologic malignancies in the region and outline a clinical service and research agenda, which builds on recent global health successes combating HIV and other infectious diseases. Achieving similar progress against hematologic cancers in sub-Saharan Africa will require the sustained collaboration and advocacy of the entire global cancer community.

Treatment with valacyclovir, famciclovir, or antiretrovirals reduces human herpesvirus-8 replication in HIV-1 seropositive men

Human herpesvirus-8 (HHV-8) replication is a key factor in Kaposi sarcoma, primary effusion lymphoma, and Castleman disease pathogenesis. In vitro data suggest that antivirals inhibit HHV-8 replication, but little data exist in humans. Daily oropharyngeal swabs were analyzed from HIV/HHV-8 dually infected men enrolled in three previous clinical trials of valacyclovir and famciclovir for HIV-1 and/or HSV-2 suppression. Fifty-eight participants contributed 6,036 swabs. HHV-8 was detected in 1,128 (19%) of 6,036 swabs, including 618 (21%) of 2,992 on placebo, 323 (15%) of 2,221 on valacyclovir, and 187 (23%) of 823 on famciclovir. After adjusting for baseline HIV viral load and highly active antiretroviral therapy (HAART) use, an 18% reduction in HHV-8 shedding frequency (IRR 0.822; P = 0.011) was found in participants on valacyclovir and a 30% reduction (IRR 0.700; P < 0.001) on famciclovir. HAART was associated with an 89% (IRR 0.129; P = 0.048) reduction in HHV-8-shedding. Neither antiviral nor antiretroviral therapy was associated with decreased HHV-8 quantity. Valacyclovir and famciclovir were associated with modest but significant reductions in HHV-8 oropharyngeal shedding frequency. In contrast, HAART was a potent inhibitor of HHV-8 replication. Studies of whether antiviral therapy in combination with ART will prevent HHV-8-associated disease appear warranted.

Pathology of Kaposi's Sarcoma-Associated Herpesvirus Infection

Kaposi’s sarcoma-associated herpesvirus (KSHV; human herpesvirus 8) is a human herpesvirus, classified as a gamma-herpesvirus. KSHV is detected in Kaposi’s sarcoma (KS), primary effusion lymphoma (PEL), and some cases of multicentric Castleman’s disease (MCD). Similar to other herpes viruses, there are two phases of infection, latent and lytic. In KSHV-associated malignancies such as KS and PEL, KSHV latently infects almost all tumor cells. Quantitative PCR analysis revealed that each tumor cell contains one copy of KSHV in KS lesions. The oncogenesis by KSHV has remained unclear. Latency-associated nuclear antigen (LANA)-1 plays an important role in the pathogenesis of KSHV-associated malignancies through inhibition of apoptosis and maintenance of latency. Because all KSHV-infected cells express LANA-1, LANA-1 immunohistochemistry is a useful tool for diagnosis of KSHV infection. KSHV encodes some homologs of cellular proteins including cell-cycle regulators, cytokines, and chemokines, such as cyclin D, G-protein-coupled protein, interleukin-6, and macrophage inflammatory protein-1 and -2. These viral proteins mimic or disrupt host cytokine signals, resulting in microenvironments amenable to tumor growth. Lytic infection is frequently seen in MCD tissues, suggesting a different pathogenesis from KS and lymphoma.

Human herpesvirus 8 seropositivity among sexually active adults in Uganda

Introduction

Sexual transmission of human herpesvirus 8 (HHV8) has been implicated among homosexual men, but the evidence for sexual transmission among heterosexual individuals is controversial. We investigated the role of sexual transmission of HHV8 in a nationally representative sample in Uganda, where HHV8 infection is endemic and transmitted mostly during childhood.

Materials and Methods

The study population was a subset of participants (n = 2681) from a population-based HIV/AIDS serobehavioral survey of adults aged 15–59 years conducted in 2004/2005. High risk for sexual transmission was assessed by questionnaire and serological testing for HIV and herpes simplex virus 2. Anti-HHV8 antibodies were measured using two enzyme immunoassays targeting synthetic peptides from the K8.1 and orf65 viral genes. The current study was restricted to 2288 sexually active adults. ORs and 95% CIs for HHV8 seropositivity were estimated by fitting logistic regression models with a random intercept using MPLUS and SAS software.

Results

The weighted prevalence of HHV8 seropositivity was 56.2%, based on 1302 seropositive individuals, and it increased significantly with age (P_trend<0.0001). In analyses adjusting for age, sex, geography, education, and HIV status, HHV8 seropositivity was positively associated with reporting two versus one marital union (OR:1.52, 95% CI: 1.17–1.97) and each unit increase in the number of children born (OR: 1.04, 95% CI: 1.00–1.08), and was inversely associated with ever having used a condom (OR: 0.64, 95% CI: 0.45–0.89). HHV8 seropositivity was not associated with HIV (P = 0.660) or with herpes simplex virus 2 (P = 0.732) seropositivity. Other sexual variables, including lifetime number of sexual partners or having had at least one sexually transmitted disease, and socioeconomic variables were unrelated to HHV8 seropositivity.

Conclusion

Our findings are compatible with the conclusion that sexual transmission of HHV8 in Uganda, if it occurs, is weak.

Mucosal Fluids and Biomarkers of Clinical Disease

Diagnostic tests for a range of oral and systemic diseases using fluids sampled from the mouth are under intense investigation and are increasingly being used. Methods exist for identification of HIV antibody and nucleic acid and for other viral infections of the mouth, such as Kaposi sarcoma herpes virus or human herpesvirus-8, which may coexist with HIV. A number of commercial test kits are available, with variable evidence of sensitivity, specificity, and utility. There is intense research on sophisticated but potentially facile handheld in-office devices for many disease markers. Challenges to their uptake require well-designed studies on their practical reliability and utility, with appropriate controls. A range of ethical, social, and political issues need to be addressed in such studies.

Do fewer cases of Kaposi's sarcoma in HIV-infected patients reflect a decrease in HHV8 seroprevalence?

Infection with human herpes virus 8 (HHV8) is associated with development of Kaposi's sarcoma (KS); therefore also known as KS-associated herpes virus. KS is closely associated with human immunodeficiency virus (HIV) infection, and consequently HHV8 seroprevalence is higher in HIV-infected compared to HIV-negative patients. Currently, KS is rarely seen in clinical practice, which might be a consequence of an optimized anti-HIV treatment leading to an improved immunological status, or alternatively of a decrease in HHV8 prevalence. To determine the prevalence of HHV8 antibodies in HIV-positive compared to HIV-negative patients from the University Hospital Frankfurt/Main, Germany, and to compare our results with previously published data to illustrate trends in the spread of infection. Hundred serum samples each of HIV-positive and HIV-negative patients were analyzed for HHV8 antibodies by using an IgG immunofluorescence test. The overall HHV8 seroprevalence was 16% with no statistically significant gender-specific differences; however, the distribution between the HIV-infected patients and the HIV-negative control group was significantly different (30 and 2%, respectively). The highest rate of seroprevalence in HIV-infected patients was detected at the age of 40-49 (42%) and the lowest rate at the age of 20-29 years (16.6%). In comparison with formerly conducted studies, our data clearly showed an increase in the HHV8 seroprevalence in HIV-infected patients, both in men and women. Therefore, we conclude that the low rate of clinical KS is associated with an improved immunological status due to an optimized anti-HIV therapy.

Simultaneous quantification of human herpesvirus 8 DNA by real time PCR in different tissues of HIV infected cuban patients with Kaposi's sarcoma

In Cuba, previous reports have shown an increase of epidemic KS, reaching a total of 120 cases by the end of 2007, despite the use of HAART. To evaluate and compare the role of human herpes virus 8 (HHV-8) viral loads in different compartments of AIDS-related Kaposi's sarcoma (AIDS-KS) patients real-time polymerase chain reaction (RT-PCR) was used to determine the genome copy number of HHV-8 in plasma, saliva, tissue and peripheral blood mononuclear cells (PBMC) of 49 AIDS-KS patients. Overall, 98% of AIDS-KS patients harbored detectable HHV-8. HHV-8 could be detected in 91.6% of KS tissue lesions showing the highest viral load (median log = 3.14 copies/100 ng DNA) followed by saliva and PBMC which were positive in 78%, and 69.2%; respectively. In contrast, HHV-8 was detected in only 37% of plasma samples, which also showed lower viral loads. Men who had sex with men (MSM) were more likely to have three-times higher HHV-8 genome copies in KS lesions when compared with tissues from heterosexuals individuals (OR 3; 95% CI 1.1 to 12.5). These results emphasize the systemic nature of HHV-8-infection and demonstrate the possible role of saliva in HHV-8 transmission among MSM.

Prevalence and correlates of human herpesvirus 8 infection among Peruvian men who have sex with men

BACKGROUND

Infection with human herpesvirus 8 (HHV-8) is common among men who have sex with men (MSM) in North America and Europe and is also found to be endemic in some regions of South America. Little is known about HHV-8 prevalence and its correlates among MSM in the Andean region.

METHODS

We assessed HHV-8 seroprevalence among 497 MSM recruited for the 2002 Peruvian HIV sentinel surveillance program using a combined HHV-8 enzyme immunoassay and immunofluorescence assay algorithm. Logistic regression analysis was used to estimate odds ratios (ORs) and their 95% confidence intervals (CIs) to determine the association between selected covariates and HHV-8 seropositivity.

RESULTS

One hundred thirty-one (66.5%, 95% CI 63.1% to 69.9%) of 197 HIV-infected and 80 (26.7%, 95% CI 24.4% to 29.0%) of 300 HIV-uninfected MSM had serologic evidence of HHV-8 infection. Factors independently associated with HHV-8 infection were education<12 years (OR 1.7, 95% CI 1.1 to 2.7), anal receptive sex with the last partner (OR 2.0, 95% CI 1.2 to 3.3), self-reported sexually transmitted infection symptoms during the last year (OR 1.9, 95% CI 1.2 to 3.0), coinfection with HIV (OR 4.2, 95% CI 2.8 to 6.4) and chronic hepatitis B (OR 4.9, 95% CI 1.5 to 15.8). MSM with long-standing HIV infection were more likely to have serologic evidence of HHV-8 infection when compared with men with recently acquired HIV (OR 3.8, 95% CI 1.7 to 9.1).

CONCLUSIONS

HHV-8 infection is common among both HIV-infected and HIV-negative MSM in Lima, Peru. HHV-8 seropositivity is correlated with anal receptive sex, self-reported sexually transmitted infection symptoms, and HIV infection among these MSM and thus seems to be sexually transmitted. HHV-8 infection seems to be acquired after HIV infection, suggesting that future studies should evaluate the mode of HHV-8 transmission and prevention strategies among HIV-uninfected MSM.

Use of saliva as a lubricant in anal sexual practices among homosexual men

OBJECTIVES

Compared with other sexually active adults, men who have sex with men (MSM) are more frequently infected with several pathogens including cytomegalovirus, hepatitis B virus, and Kaposi sarcoma-associated herpesvirus. Because one common element between these organisms is their presence in saliva, we evaluated saliva exposure among MSM in a heretofore relatively unrecognized route-via use of saliva as a lubricant in anal sex.

METHODS

MSM in a San Francisco population-based cohort were interviewed regarding use of saliva by the insertive partner as a lubricant in various anal sexual practices.

RESULTS

Among 283 MSM, 87% used saliva as a lubricant in insertive or receptive penile-anal intercourse or fingering/fisting at some point during their lifetime; 31%-47% did so, depending upon the act, in the prior 6 months. Saliva use as a lubricant was more common among younger men and among HIV-infected men when with HIV-infected partners. Even among MSM following safe sex guidelines by avoiding unprotected penile-anal intercourse, 26% had anal exposure to saliva via use as a lubricant.

CONCLUSIONS

Among MSM, use of saliva as a lubricant is a common, but not ubiquitous, practice in anal sex. The findings provide the rationale for formal investigation of whether saliva use in this way contributes to transmission of saliva-borne pathogens in MSM.

Awareness of Kaposi's sarcoma-associated herpesvirus among men who have sex with men

BACKGROUND

Despite burgeoning scientific knowledge about Kaposi's sarcoma-associated herpesvirus (KSHV), the etiologic agent of Kaposi's sarcoma (KS), little is known about awareness of this virus in the general community. This is particularly the case for men who have sex with men (MSM), the group at greatest risk for infection.

METHODS

The California Health Interview Survey was a random digit- dial survey of over 50,000 households. Men aged 18 to 64 years who self-identified as gay or bisexual were subsequently recontacted for a follow-up study of HIV-related knowledge and behavior in which they were asked if they had heard of KS and to describe the cause of KS.

RESULTS

Of 398 MSM interviewed, 73.0% (95% CI 65.0-79.7) had heard of KS. However, only 6.4% (95% CI 4.4-9.2) of participants correctly identified that KS is caused by KSHV or a virus other than HIV. Postgraduate education, urban residence, and concurrent HIV infection were all independently associated with greater awareness of the viral origin of KS.

CONCLUSION

Awareness of KSHV is very low, overall, among MSM and only somewhat higher, but still unacceptably low, among HIV-infected MSM. Significant efforts are needed to increase awareness of KSHV as a sexually transmitted infection in this population.

HIV/AIDS: epidemiology, pathophysiology, and treatment of Kaposi sarcoma-associated herpesvirus disease: Kaposi sarcoma, primary effusion lymphoma, and multicentric Castleman disease

Kaposi sarcoma-associated herpesvirus infection is associated with the development of 3 proliferative diseases: Kaposi sarcoma, primary effusion lymphoma, and multicentric Castleman disease. These conditions are also intimately associated with human immunodeficiency virus infection, and important synergistic interactions between these 2 viruses have been described. Despite differences in viral gene expression patterns in each condition, Kaposi sarcoma-associated herpesvirus encodes similar oncogenic proteins that promote the activation of sequential and parallel signaling pathways. Therapeutic strategies have been implemented to target these unique signaling pathways, and this sort of molecular targeting is the focus of many current research efforts. The scope of this review is to present contemporary knowledge about the epidemiology, virology, and immunology of Kaposi sarcoma-associated herpesvirus and to highlight several key oncogene products that may be targets for chemotherapy.

New approaches to the treatment of human herpesvirus 8-associated disease

Human herpesvirus 8 (HHV-8, also known as Kaposi sarcoma-associated herpesvirus or KSHV) is the etiologic agent of Kaposi sarcoma (KS) and primary effusion lymphoma (PEL), as well as many cases of Castleman disease. Despite significant advances in understanding the biology and natural history of these diseases, current treatment options have important limitations, and strategies to prevent their development in high-risk individuals are lacking. This article reviews the scope of HHV-8-associated disease, as well as the efficacy of current treatment options. Finally, novel approaches to treatment and prevention are described, including antiviral agents, targeted molecular therapy and a combination of these modalities.

Transmission of human herpesvirus 8: an update

PURPOSE OF REVIEW

Human herpesvirus 8 is associated with neoplastic diseases in the immunocompromised host, including Kaposi's sarcoma, multicentric Castleman disease and primary effusion lymphoma. Acquisition and control of human herpesvirus 8 infection have not yet been fully elucidated. This review focuses on the most recent findings on human herpesvirus 8 transmission.

RECENT FINDINGS

Horizontal transmission by saliva appears the most common route not only in families in endemic regions, but also among high-risk groups in Western countries. Vertical, sexual, and blood and transplant-related transmission, however, remain of significant concern worldwide. Novel approaches to standardize and optimize the assessment of human herpesvirus 8 infection have been reported. New insights on the host immune cell mechanisms devoted to the control of human herpesvirus 8 infection have also been presented.

SUMMARY

The increasing knowledge about the routes of human herpesvirus 8 transmission, which appear now more similar to those of other more ubiquitous human herpesviruses (i.e. Epstein-Barr virus and cytomegalovirus), the growing efforts in improving laboratory diagnosis and the caution in the research of new biological associations are the major recent findings. They constitute a fundamental background for directing more appropriate future research and achieving more stringent evidence useful for the control of human herpesvirus 8 spread and for the management of human herpesvirus 8-related diseases.

Frequent and asymptomatic oropharyngeal shedding of human herpesvirus 8 among immunocompetent men

BACKGROUND

Little is known about the clinical and virologic manifestations of human herpesvirus (HHV)-8 infection in immunocompetent persons in the absence of malignancy.

METHODS

A total of 46 human immunodeficiency virus-negative, HHV-8-seropositive men collected saliva daily, and 25 recorded 15 common symptoms daily (gastrointestinal, constitutional, and oropharyngeal) and absences from work or school. Quantitative polymerase chain reaction measured HHV-8 DNA in saliva.

RESULTS

Some 44 (96%) of 46 men reported having sex with men (MSM). Of the 44 MSM, 27 (61%) had HHV-8 detected in saliva on > or = 1 day; heterosexual men also shed HHV-8. In analyses restricted to MSM, HHV-8 DNA was detected on 636 (22%) of 2897 days. Among MSM with HHV-8 detected in saliva, the median rate was 20% (range, 1%-100%), with 30% shedding on > 50% of days, and the median quantity was 4.5 log10 copies/mL (range, 2.0-7.3 log10 copies/mL). The quantity of HHV-8 shed was lower in nonwhites (P<.001) and younger participants (P=.03). The frequency of HHV-8 detection and quantity were correlated (r=0.62; P<.001). Symptoms were reported on 10 (9%) of 114 days when HHV-8 was present, compared with 78 (9%) of 830 days without (odds ratio, 0.93 [95% confidence interval, 0.30-2.88]; P=.9).

CONCLUSIONS

HHV-8 is detected frequently and intermittently in the saliva of chronically infected immunocompetent MSM, but this infection is asymptomatic.

High risk of human immunodeficiency virus in men who have sex with men with herpes simplex virus type 2 in the EXPLORE study

The relation between herpes simplex virus type 2 (HSV-2) and human immunodeficiency virus (HIV) acquisition was evaluated among 4,295 high-risk, HIV-negative men who have sex with men in an intensive behavioral intervention (colloquially referred to as "EXPLORE") study in the United States from 1999 to 2003. Sexual behavior data were obtained by computer-assisted self-interview, and sera were collected semiannually for HIV and HSV-2 serology. HSV-2 infection was classified as "recent incident" (at the first HSV-2 seropositive visit), "remote incident" (within 24 months of the first positive visit), and "prevalent" (for visits >24 months after the first HSV-2 positive visit). Baseline HSV-2 prevalence was 20.3%. HSV-2 incidence was 1.9 (95% confidence interval (CI): 1.6, 2.2) per 100 person-years; significant risk factors were African-American race, unprotected receptive anal intercourse, an HIV-positive male sex partner, and six or more male partners in the prior 6 months. The behavioral intervention did not reduce HSV-2 acquisition (adjusted hazard ratio (HR) = 1.2, 95% CI: 0.9, 1.6). Overall HIV incidence was 1.9 (95% CI: 1.7, 2.2) per 100 person-years. HIV risk was elevated among men who have sex with men with recent incident HSV-2 (adjusted HR = 3.6, 95% CI: 1.7, 7.8), remote incident HSV-2 (adjusted HR = 1.7, 95% CI: 0.8, 3.3), and prevalent HSV-2 (adjusted HR = 1.5, 95% CI: 1.1, 2.1) infection compared with HSV-2 seronegative participants. HIV intervention strategies targeting HSV-2 prevention and suppression among men who have sex with men should be evaluated.