Kaposi's sarcoma-associated herpesvirus seroprevalence in selected german patients: evaluation by different test systems

Human Herpesvirus 8 in Australia: DNAemia and Cumulative Exposure in Blood Donors

Human herpesvirus 8 (HHV-8), the causative agent of Kaposi’s sarcoma, multicentric Castleman’s disease and primary effusion lymphoma, predominantly manifests in immunocompromised individuals. However, infection in immunocompetent individuals does occur. The prevalence of HHV-8 exposure in blood donors from non-endemic countries ranges between 1.2% and 7.3%. Nothing was known about the prevalence in Australian blood donors. Therefore, this study investigated the active and cumulative exposure of HHV-8 in this cohort. Plasma samples (n = 480) were collected from eastern Australian blood donors and were tested for HHV-8 DNA by qPCR, and for HHV-8 antibodies by two different ELISAs. Samples initially positive on either ELISA were retested in duplicate on both, and on a mock-coated ELISA. Any samples positive two or three out of the three times tested on at least one ELISA, and repeat negative on the mock-coated ELISA, were assigned as repeat positive. None of the 480 samples tested contained HHV-8 DNA. Serological testing revealed 28 samples (5.83%; 95% CI: 3.74−7.93%) had antibodies to HHV-8. There was no difference (p > 0.05) in seropositivity between sex or with increasing age. This is the first study to show serological evidence of cumulative HHV-8 exposure and no HHV-8 DNAemia within a select blood donor population in Australia. Our molecular and serological data is consistent with published results for blood donors residing in HHV-8 non-endemic countries, which shows the prevalence to be very low.

Seroprevalence of human herpesvirus 8 in Ireland among blood donors, men who have sex with men, and heterosexual genitourinary medicine and infectious diseases clinic attendees

Human herpesvirus 8 (HHV-8) seroprevalence varies geographically and between subpopulations. High seroprevalence rates have been ascribed to men who have sex with men (MSM), African migrants, and HIV-infected individuals. The objective of this study was to determine the seroprevalence of HHV-8 in an Irish population, including specific risk groups. A cross-sectional study of 200 blood donors and 200 genitourinary medicine (GUM) and infectious diseases (ID) clinic patients was performed, with testing for Immunoglobulin G (IgG) antibodies to HHV-8 lytic antigens using a commercial indirect fluorescence assay (Scimedx Corp.). Verification was performed at the Centers for Disease Control and Prevention (CDC). All 200 blood donor samples were negative for HHV-8 IgG antibodies. 21% of GUM and ID patients were positive for HHV-8 IgG antibodies. One hundred of these patients were MSM, 35% of whom were HHV-8 seropositive (46% of HIV-positive MSM and 24% of HIV-negative MSM). Of 100 heterosexual patients, only 7% were HHV-8 seropositive. The absence of seropositivity in 200 Irish blood donors may suggest that Ireland has a low overall population HHV-8 seroprevalence. The proportion of HHV-8 seropositivity in the MSM population was significantly higher than in the heterosexual population and most marked in HIV-positive MSM.

High seroprevalence of antibodies against Kaposi's sarcoma-associated herpesvirus (KSHV) among HIV-1-infected children and adolescents in a non-endemic population

Human herpesvirus-8 (HHV-8) is the etiological agent of Kaposi's sarcoma (KS), which primarily affects human immunodeficiency virus (HIV)-infected adults with advanced immunodeficiency. Currently, only limited prevalence data for HHV-8 infection in HIV-infected children living in non-endemic areas are available. This multicenter cross-sectional study was conducted in four university hospitals in Germany specializing in pediatric HIV care. Stored serum specimens obtained from 207 vertically HIV-1-infected children and adolescents were tested for antibodies against lytic and latent HHV-8 antigens. Logistic regression was used to assess independent risk factors associated with HHV-8 seropositivity. The overall HHV-8 seroprevalence was 24.6 % (n = 51/207) without significant differences related to sex, age, or ethnicity. In univariate analysis, HHV-8 seropositivity was significantly associated with a child having being born outside Germany, maternal origin from sub-Saharan Africa, a history of breastfeeding, CDC immunologic category 3, and deferred initiation of antiretroviral therapy (>24 months of age). In multivariate analysis, a child's birth outside Germany was the only significant risk factor for HHV-8 seropositivity (odds ratio 3.98; 95 % confidence interval 1.27-12.42). HHV-8-associated malignancies were uncommon; only one patient had a history of KS. Serum specimen of vertically HIV-infected children and adolescents living in Germany showed a high HHV-8 seroprevalence. These findings suggest that primary HHV-8 infection-a risk factor for KS and other HHV-8-associated malignancies-occurs early in life. Thus, management of perinatally HIV-infected children should include testing for HHV-8 coinfection and should consider future risks of HHV-8-associated malignancies.

Human herpesvirus type 8 in tuberculosis patients with effusion

Background

Many patients with tuberculosis (TB) are seropositive for human herpesvirus type 8 (HHV-8), and many patients with primary effusion lymphoma have high levels of HHV-8 DNA in their effusions. However, the status of HHV-8 in the effusions of patients with TB remains unclear.

Methods

Blood samples were collected from 129 patients with pulmonary TB and 129 age- and sex-matched healthy controls. Forty of the TB patients had pleural or peritoneal effusions, and 38 of these effusions were available. Both blood and effusion samples were analyzed for lymphocyte and monocyte counts and/or HHV-8 antibodies and DNA.

Results

TB patients with or without effusions had significantly greater HHV-8 seropositivity (p = 0.009) and titers of HHV-8 antibodies (p = 0.005) than healthy controls. The seropositivity and blood titers of HHV-8 antibodies were similar in TB patients with and without effusions. Among TB patients with effusions, similar percentages had seropositive plasma and seropositive effusions. Plasma samples of 6 TB patients, but none of the healthy controls, were positive for HHV-8 DNA (p = 0.03). TB patients with or without effusions had lower blood lymphocyte counts and higher blood monocyte counts than healthy controls (p < 0.0001 for both). TB patients with effusions had significantly lower blood lymphocyte counts than those without effusions (p = 0.035).

Conclusions

HHV-8 had similar seroprevalence in TB patients with and without effusions. However, TB patients with effusions had lower blood lymphocyte counts than those without effusions.

Utilising proteomic approaches to understand oncogenic human herpesviruses (Review)

The γ-herpesviruses Epstein-Barr virus and Kaposi's sarcoma-associated herpesvirus are successful pathogens, each infecting a large proportion of the human population. These viruses persist for the life of the host and may each contribute to a number of malignancies, for which there are currently no cures. Large-scale proteomic-based approaches provide an excellent means of increasing the collective understanding of the proteomes of these complex viruses and elucidating their numerous interactions within the infected host cell. These large-scale studies are important for the identification of the intricacies of viral infection and the development of novel therapeutics against these two important pathogens.

High prevalence of human herpesvirus type 8 infection in patients with pulmonary tuberculosis in Taiwan

Blood samples were collected from 101 untreated pulmonary tuberculosis (TB) patients and 101 age- and sex-matched healthy control subjects. TB patients had lower lymphocyte and a higher monocyte counts than control subjects (p <0.0001 for both). The seropositive rate of human herpesvirus (HHV) type 8 antibody was higher in patients (30/101) than in control subjects (15/101) (p = 0.01). Antibody titres in patients also exceeded those in control subjects (p 0.006). Lymphocyte and monocyte counts between seronegative and seropositive subjects were not different. Four patients were positive for HHV-8 DNA. The study revealed a significantly higher HHV-8 seroprevalence in untreated pulmonary TB patients than in general population.

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.

HIV-associated Kaposi sarcoma: pathogenic mechanisms

Kaposi sarcoma (KS) is a multicentric angioproliferative disorder characterized by spindle cell proliferation, neo-angiogenesis, inflammation, and edema. Human herpesvirus (HHV)-8, a gamma-herpesvirus, is a critical factor, but is not alone sufficient for the initiation of KS. Other cofactors such as human immunodeficiency virus (HIV), host-derived cytokines, chemokines, and growth factors are required for the development of KS. Whether HIV-associated KS is a reactive hyperplastic inflammatory lesion or a true neoplasm is still controversial. It is likely that HIV-associated KS begins as a reactive disorder that in some cases progresses to a monoclonal, an oligoclonal, and a polyclonal neoplasm.

[The morphologic variants of KSHV/HHV 8-associated lymphoproliferations]

KSHV/HHV 8 infection is associated with primary effusion lymphoma, multicentric Castleman disease (MCD) and MCD-associated plasmablastic lymphoma. We report the case of an HIV-infected male with Kaposi sarcoma, MCD in the lymph node and development of a KSHV/HHV 8-associated plasmablastic lymphoma in the liver. Immunohistochemistry revealed an HHV 8 infection of plasmablasts showing cytoplasmic IgM/lambda expression. To the best of our knowledge, liver infiltration by a MCD-associated HHV 8 positive plasmablastic lymphoma has not been documented previously. The differential diagnosis is discussed.

Seroprevalence of six different viruses among pregnant women and blood donors in rural and urban Burkina Faso: A comparative analysis

A seroprevalence study was carried out of six different human pathogenic viruses, namely human immunodeficiency virus (HIV), hepatitis B virus (HBV), hepatitis C virus (HCV), human T-cell leukemia virus (HTLV), human herpesvirus type 8 (HHV-8), and dengue virus among pregnant women and blood donors from rural (Nouna) and urban (Ouagadougou) Burkina Faso, West Africa. A total of 683 samples from blood donors (n = 191) and pregnant women (n = 492) were collected from both sites and screened for the different virus infection markers resulting in the following prevalence values for Nouna or Ouagadougou, respectively: HIV 3.6/4.6, anti-HBV core (anti-HBc) 69.6/76.4, HBV surface antigen (HBsAg)14.3/17.3, HCV 2.2/1.5, HTLV 1.4/0.5, HHV-8 11.5/13.5, dengue virus 26.3/36.5. Individuals aged > or =25 years were more likely to be infected with HIV than those below 24 years (P < 0.05). Infection with HIV increased the likelihood of co-infection with other viruses, such as HHV-8, HBV and HTLV. Co-infection studies involving five viruses (HBV-HBsAg, HHV-8, HIV, HCV, and HTLV) showed that 4.8% (33/683) of the studied population were dually infected, with HBsAg+ HHV-8 (13/33), HBsAg+HIV (8/33) and HIV+HHV-8 (8/33) being the most common co-infections. Of the population studied 0.6% (4/683) was triply infected, the most common infection being with HBV+HIV+HHV-8 (3/4). There was no difference in the prevalence of HIV, anti-HBc, HBsAg, HCV, HTLV, and HHV-8 either among blood donors or pregnant women in urban or rural setting, while dengue virus prevalence was relatively lower in rural (26.3%) than in urban (36.5%) Burkina Faso.

Human herpesvirus 8--a novel human pathogen

In 1994, Chang and Moore reported on the latest of the gammaherpesviruses to infect humans, human herpesvirus 8 (HHV-8) [1]. This novel herpesvirus has and continues to present challenges to define its scope of involvement in human disease. In this review, aspects of HHV-8 infection are discussed, such as, the human immune response, viral pathogenesis and transmission, viral disease entities, and the virus's epidemiology with an emphasis on HHV-8 diagnostics.

Kaposi's sarcoma-associated herpesvirus: clinical, diagnostic, and epidemiological aspects

Kaposi's sarcoma-associated herpesvirus (KSHI) is one of the few viruses proven to be associated with tumorigenesis in humans. Its causal association with all clinical and epidemiological variants of Kaposi's sarcoma (KS) is well established. KSHV is also involved in the pathogenesis of primary effusion lymphoma (PEL) and a subset of multicentric Castleman's disease (MCD). Possible associations of KSHV with other clinical settings have been extensively examined. The findings from several of these studies are contradictory and are yet to be resolved. Concentrated effort over the last decade, since the initial discovery of KSHV, led to the development of several experimental systems that resulted in a better comprehension of the biological characteristics of KSHV and set the stage for the understanding of mechainisms by which diseases are induced by the virus. The development of molecular, histological, and serological tools for KSHV diagnosis allowed researchers to track the transmission and to study the epidemiology of KSHV. These assays have been applied, in particular in ambiguous cases, in order to confirm clinically and pathologically based diagnoses. Here, we review the advances in the clinical, experimental, diagnostic, and epidemiological research of KSHV.