Detection of Kaposi's sarcoma-associated herpesvirus-like DNA sequence in angiosarcoma.

The partial DNA sequence of a putative new herpesvirus has recently been isolated from almost all cases of Kaposi''s sarcoma (KS), from a small subset of AIDS-related lymphomas, and from a high proportion of multicentric Castleman''s disease. The presence of this KS-associated herpesvirus, which is also known as human herpes virus 8 (KSHV/ HHV8), has not been reported in vascular tumors other than KS. We therefore examined a series of vascular neoplasms of both endothelial and pericyte derivation using polymerase chain reaction to detect a 233-hp segment of the viral DNA. KSHV/HHV8 sequences were found in 7 of 24 (29%) angiosarcomas and 1 of 20 (5%) hemangiomas but not in any hemangiopericytomas (0 of 6). The presence of the virus in angiosarcoma was confirmed by direct sequencing of the polymerase chain reaction product and Southern blotting in one case each. Only one of the affected patients was known to be immunocompromised. By detecting its presence in a significant proportion of angiosarcomas, this study extends the number of tumors associated with KSHV/HHV8, further tightens its association with malignancy, and suggests a tropism of the virus for endothelial cells. The presence of KSHV/HHV8 in angiosarcomas in addition to classical KS also indicates that immunosuppression is not a requisite for viral infection.     

HHV8 and female Kaposi's sarcoma

Kaposi's sarcoma (KS) is an enigmatic tumour of uncertain histogenesis. Epidemiological data have long suggested that KS may be caused by an infectious agent, possibly sexually transmitted. Following the documentation of human herpesvirus 8 (HHV8) and its strong association with all forms of KS, it now appears that the putative agent has at last been identified. As KS is rare in females, a unique group was screened for the presence of HHV8 using both conventional solution-phase polymerase chain reaction (PCR) and the newly described technique of TaqMan® PCR. The presence of HHV8 was demonstrated in 10/12 of these female patients. This further supports the direct role of HHV8, in conjunction with cytokines and other factors, in the pathogenesis of KS. © 1997 John Wiley & Sons, Ltd.     

Localization of human herpes-like virus type 8 in vascular endothelial cells and perivascular spindle-shaped cells of Kaposi's sarcoma lesions by in situ hybridization.

Kaposi''s sarcoma (KS) is a neoplasm that develops as multifocal lesions characterized by a histological picture that includes irregularly shaped vascular spaces surrounded by perivascular and interstitial spindle-shaped cells, extravasated erythrocytes, and an inflammatory mononuclear cell infiltrate. Recently, the DNA sequences of a novel human gamma-herpesvirus-like (HHV-8) agent have been detected by polymerase chain reaction in KS associated with acquired immune deficiency syndrome (AIDS-KS), classical KS, and African endemic KS. The present study was done to identify the specific cells within KS tumors that contain the viral DNA. Fourteen skin biopsy specimens, including three classical KSs, six AIDS-KSs, three normal skin specimens, and two common warts from healthy individuals, were examined by polymerase chain reaction for the presence of the HHV-8 DNA sequences. HHV-8 DNA were present in all nine KS specimens but not detectable in the five non-KS tissue samples. Using in situ hybridization, we found the HHV-8 DNA sequences to be predominantly localized to the nuclei of endothelial cells lining the vascular slits and some perivascular spindle-shaped cells, in two of three KS and four of six AIDS-KS tissue sections examined. The HHV-8-positive cells of KS specimens were concurrently shown to also be positive for factor-VIII-related antigen by immunohistochemical staining. The presence of the DNA of HHV-8 in the nuclei of KS cells further supports the possibility that this agent may play a role in the pathogenesis of this tumor.     

Ultrastructural characterization of human herpesvirus 8 (Kaposi's sarcoma- associated herpesvirus) in Kaposi's sarcoma lesions: electron microscopy permits distinction from cytomegalovirus (CMV)

Kaposi's sarcoma (KS) has been shown by molecular techniques to be associated with infection with human herpesvirus 8 (HHV8/KSHV), but specific ultrastructural characterization of the virus has been impaired by the frequent presence in these lesions of other herpesviruses, particularly cytomegalovirus (CMV). Since the ultrastructural appearance of HHV8/KSHV has been studied in the cell line KS-1 uninfected with other viruses including CMV, it was possible to undertake a comparative study of CMV and HHV8/KSHV in KS lesions. HHV8/KSHV was sparsely present and lytic infection was restricted to endothelial cells. The following specific ultrastructural features allowed distinction between HHV8/KSHV and CMV: the viral particles were more delicate and less numerous in cases of HHV8/KSHV infection; the viral tegument was more electron-dense in CMV than in HHV8/KSHV; dense bodies characteristic of CMV were absent in HHV/KSHV; complete CMV viral particles were more variable in size and generally larger (150–200 nm) than HHV8/KSHV (120–150 nm); and finally, the viral envelope was more pleomorphic in CMV than in KSHV/HHV8. Similarities between CMV and HHV8/KSHV included the basic structure of the nucleocapsids and the presence of capsids lacking central DNA cores (so-called non-infectious enveloped particles). These observations show that electron microscopy can be used to identify HHV8/KSHV and confirm the relationship between HHV8/KSHV and KS. © 1997 John Wiley & Sons, Ltd.     

Molecular analysis of clonality in Kaposi's sarcoma.

BACKGROUND: Kaposi''s sarcoma is considered to be an angioproliferative disease associated with a novel herpesvirus (KSHV/HHV8), but the precise pathophysiology of the lesion remains unclear. The study of clonality in Kaposi''s sarcoma using X linked DNA polymorphism has been difficult so far, because of a very strong prevalence of the disease in males. AIMS: To study the clonality of Kaposi''s sarcoma lesions. METHODS: An assay based on a methyl sensitive restriction digest followed by polymerase chain reaction (PCR) amplification of the highly polymorphic human androgen receptor (HUMARA) gene was used. Tissues from Kaposi''s sarcoma lesions and control tissues from the same patients were obtained from seven females, four with classic Kaposi''s sarcoma and three with AIDS associated Kaposi''s sarcoma. A cutaneous angiosarcoma was also analysed, for comparative purposes, and showed evidence of clonality after HpaII digestion. RESULTS: All patients were heterozygous for the HUMARA polymorphism and informative for analysis. In all patients, including four with a nodular form of Kaposi''s sarcoma and more than 70% spindle cells in the lesion, a polyclonal pattern of inactivation could be demonstrated. CONCLUSIONS: The Kaposi''s sarcoma lesion is first of all a polyclonal cell proliferation.     

Kaposi's sarcoma-associated herpesvirus (KSHV)/human herpesvirus 8 (HHV8)—a new human tumour virus

Recently, a novel DNA virus has been molecularly cloned from Kaposi's sarcoma (KS) tissue, a tumour common in acquired immune deficiency syndrome (AIDS). Analysis of the viral genome confirms that it is a relative of human herpesviruses and the virus has been designated HHV-8. Epidemiological evidence suggests a strong aetiological link between the presence of HHV-8 DNA and/or antibodies against the virus, and KS. Additional sequence analysis suggests that the HHV-8 genome contains sequences which encode a D type cyclin and a number of other genes potentially implicated in growth deregulation which may be relevant to its proposed role as a transforming virus. © 1997 John Wiley & Sons, Ltd.     

Patterns of antibodies against latent and lytic antigens of human herpesvirus 8 in an endemic population and patients with Kaposi's sarcoma in Mozambique

The patterns of antibodies against latent and lytic antigens of human herpesvirus 8 (HHV‐8) were assessed using immunofluorescence assays of samples from 155 persons seropositive for HHV‐8 seen at public health centers and 24 patients with Kaposi's sarcoma (KS) from Mozambique. Of the 155 persons without KS, 48 (31%) had antibodies against latent antigens only, 29 (18.7%) had antibodies against lytic antigens only, and 78 (50.3%) had antibodies against both types of antigen. The HHV‐8 antibody titer tended to increase with age until age 40, after which it began to decrease. High titers of antibodies against latent and lytic antigens of HHV‐8 were detected mostly in persons co‐infected with HIV, and these increased titers could have a predictive value. All patients with KS except four patients who were seronegative for HHV‐8 had elevated titers of HHV‐8 antibodies, predominantly against latent antigens. The data suggest the potential for an increase in the development of KS in this endemic area for HHV‐8. J. Med. Virol. 82:1576–1581, 2010. © 2010 Wiley‐Liss, Inc.     

Consistent polymerse chain reaction–single-strand conformation polymorphism pattern of human herpesvirus-8 in the course of classical Kaposi's sarcoma assumes its clonal origin

There is emerging evidence that Kaposi's sarcoma–associated herpesvirus (KSHV or HHV-8) has a central role in the pathogenesis of Kaposi's sarcoma (KS). The occurrence of HHV-8 in classical KS biopsies is reported irrespective of its clinical stage (patch, plaque, nodular). HHV-8 was detected in 25 of 28 formalin-fixed paraffin-embedded classical KS samples by nested polymerase chain reaction. In addition, in six patients multiple tumors were available (n = 21). Single-strand conformation polymorphism (SSCP) analysis of the amplicons showed uniform SSCP pattern of samples belonging to the same patient regardless of whether the KS was multiplex or developed again years after the first excision. Most of the SSCP patterns were confirmed by further sequence analysis. The presence of the same sequence variant of HHV-8 in various samples of the same patient supports the clonal origin of classical Kaposi's sarcoma. J. Med. Virol. 54:300–304, 1998. © 1998 Wiley-Liss, Inc.     

National Society for Histotechnology SymposiumlConvention November 16-20,1981

Abstract

Human herpes virus 8 (HHV8) has been consistently implicated in the pathogenesis of Kaposi's sarcoma (KS) and has been studied in a variety of skin lesions, principally by means of polymerase chain reaction. With this in mind, we sought to characterize a variety of skin lesions by means of paraffin immunoperoxidase studies using the antibody to the HHV8 latent nuclear antigen 1. We studied a variety of benign and malignant vascular lesions, including KS (eight cases), hemangiomas (six), angiolymphoid hyperplasia (three), and angiosarcoma (two). In addition, we assessed antibody staining in lymphomatoid papulosis (LYP; 5 cases), pityriasis lichenoides et varioliforrnis acuta (5), and pityriasis rosea (5) as well as a variety of lnesenchymal and epithelial primary cutaneous tumors (nine cases). In accordance with previous studies, all cases of KS (8/8) showed positive staining with HHV8 in a granular nuclear pattern; staining was limited to tumor cells. None of the other cutaneous tumors or inflammatory conditions showed any staining (0/35). HHV8 is a useful tool in confirming the diagnosis of cutaneous KS. Consistent with previous studies, HHV8 was not demonstrated in LYP and, novel to this study, was not found in pityriasis rosea or pityriasis lichenoides et varioliformis acuta. Paraffin ilnmunoperoxidase with HHV8 latent nuclear antigen 1 is a viable alternative to polymerase chain reaction and can be used in diagnostic and research capacities with consistent results. (The J Histotechnol 28:67, 2005)

Submitted November 30, 2004; accepted with revisions April 6, 2005     

Human herpesvirus 8 (Kaposi's sarcoma-associated herpesvirus) DNA in Kaposi's sarcoma lesions,AIDS Kaposi's sarcoma cell lines,endothelial Kaposi's sarcoma simulators,and the skin of immunosuppressed patients.

We used the polymerase chain reaction on 63 tissue specimens of histologically staged classic Kaposi''s sarcoma (KS) from 40 patients, 14 specimens from 14 acquired immune deficiency syndrome (AIDS)-KS cases (all from the same geographic area over a 10-year period), and peripheral blood mononuclear cells from 1 of the non-AIDS KS patients to amplify a specific 210-bp genomic sequence of the newly discovered KS-associated herpesvirus (KSHV). Also tested were 86 benign and malignant endothelial lesions, which potentially simulated each KS histological stage and were further matched by age approximation and by sex with a classical KS specimen. The lesions included hemangioma, lymphangioma, pyogenic granuloma, and angiosarcoma. KSHV was also sought in multiple well characterized vascular endothelial cell lines from AIDS-KS lesions and in 20 mainly cutaneous benign and malignant lesions from 15 immunosuppressed transplant patients. Overall, 92% of KS tissue specimens, representing 88% of classical KS and 100% of AIDS-KS patients, and in addition the sample of peripheral blood mononuclear cell DNA, were positive as visualized on ethidium bromide gels and confirmed by Southern blot hybridization (only 1 case was negative on gell visualization but positive on Southern blot), thus confirming the close association of KSHV with KS of different clinical forms. None of the various other endothelial lesion, skin lesions in immunosuppressed patients, or AIDS-KS endothelial cell lines contained amplifiable KSHV DNA, which indicates that reactivation of KSHV is not present in the skin lesions of immunosuppressed patients and probably is not a ubiquitous agent that secondarily infects proliferative endothelium. The absence of amplifiable virus DNA in the cultured endothelium of KS suggests that the stimulus for angioproliferation originates in another host cell or under conditions not reproduced in culture. The polymerase chain reaction is a specific and sensitive means of verifying KS in the differential diagnosis of angioproliferative lessons.     

A comparative study of the frequency of antibody and titers against human herpesvirus 8 latent and lytic antigens in “at‐risk” individuals and among patients with Kaposi's sarcoma

Differences in the prevalence of human herpesvirus 8 (HHV‐8) and Kaposi's sarcoma (KS) have been described, depending on the study population and their geographic origin. A cross‐ sectional study aimed at detecting the frequency and titers of antibodies against HHV‐8 latent and lytic antigens in serum samples from individuals with different risk‐factors for HHV‐8 infection, as well as predictive marker identification in patients with KS, was conducted. Serum samples were collected from seven groups of individuals: 75 patients with AIDS‐KS, 5 with classic KS, 16 with African KS, 495 with HIV/AIDS, 805 patients with chronic kidney disease, 683 handicapped individuals, and 757 health care workers. Samples were evaluated for the presence and titers of HHV‐8‐specific antibodies to latent and lytic antigens using “in house” immunofluorescence assays. The results were analyzed by the Chi‐square, Fisher's exact test, Kruskal–Wallis and/or Mann–Whitney U‐tests. The frequencies of HHV‐8 antibodies were as follows: 87.5–100% in patients with KS, 20.4% in patients with HIV/AIDS, 18% in patients with chronic kidney disease, 1.6% in handicapped individuals, and 1.1% in health care workers. A greater number of samples were antibody positive to lytic antigens. Elevated titers of antibodies to latent and lytic antigens, mostly among patients with KS, were detected. Using established serological assays, different “at‐risk” populations for HHV‐8 infection/disease were detected in this geographic area, confirming HIV/AIDS and identifying patients with chronic kidney disease as high‐risk groups. It is suggested that a longitudinal evaluation of antibody titers in patients with chronic kidney disease be undertaken to confirm their predictive value in the development of KS. J. Med. Virol. 81:1292–1297, 2009. © 2009 Wiley‐Liss, Inc.     

Intrahost genetic variability of human herpes virus‐8

Studies were conducted to determine whether HHV‐8 hyperactivity could be the consequence of the propensity of the host to multiple HHV‐8 infection. The aim of the present work was to investigate HHV‐8 intrahost genetic variability. HHV‐8 subgenomic DNA was amplified by PCR from patients infected with HIV, health care workers (HCW) and bone marrow transplant recipients (BMT), and from oral lesional tissues of AIDS‐Kaposi's sarcoma (KS) patients. As controls, blood from HIV‐negative health care workers, and the cell lines BC‐1, BC‐2, and BCP‐1 were used. Clones derived from amplicons originating from DNA fragments in open reading frame (ORF) 26 and ORF K1 were isolated. For each ORF, intra‐specimen nucleotide sequence differences were determined. The extent of HHV‐8 variation in clones derived from blood of patients infected with HIV was significantly higher than in blood from health care workers or post‐bone marrow transplantation patients or in AIDS‐KS tissue. Among the clones derived from the latter three categories of specimens, sequence variations were not significant. It is concluded that HIV‐infected individuals can have multiple of HHV‐8, but AIDS‐KS lesions are associated with infection by a single HHV‐8 variant or a small group of related variants. J. Med. Virol. 85:636–645, 2013. © 2013 Wiley Periodicals, Inc.     

Molecular epidemiology of human herpesvirus 8 variants in Kaposi's sarcoma from Iranian patients

Kaposi's sarcoma (KS) is a rare cancer in Iran and there is no epidemiological and molecular information about HHV-8 variants circulating among the Iranian population. In this study HHV-8 sequences have been analyzed in 43 cutaneous KS biopsies from Iranian patients mainly affected by classic KS. DNA samples were subjected to PCR amplification of HHV-8 ORF26, T0.7 and K1 followed by direct nucleotide sequencing and phylogenetic analysis. The analysis of ORF26 showed that 30 (69.8%) and 13 (30.2%) samples belonged to subtypes A/C and K, respectively. In general, the clustering of HHV-8 T0.7 variants paralleled that of ORF26. Genotyping of K1 sequences showed that the majority of samples (39 out of 41) fall into the large C clade with only 2 belonging to the A clade. In conclusion, HHV-8 variants identified among classic Iranian KS are largely related to Eurasian genotypes previously identified in KS from Mediterranean, Middle East, and East Asian regions.     

Detection of several types of human papilloma viruses in AIDS-associated Kaposi's sarcoma

Epidemiological studies indicate that acquired immunodeficiency syndrome (AIDS)-associated Kaposi's sarcoma (KS) may be caused by an infectious, preferentially sexually transmitted agent. Infections with human papilloma viruses are common, sexually transmitted diseases occurring frequently in homosexual men, who are also the main risk group of developing KS. In order to evaluate the possible role of HPV in the development of KS, 24 cutaneous AIDS-associated Kaposi's sarcomas were investigated by the polymerase chain reaction (PCR) and by in situ hybridization for the presence of human papilloma viruses (HPV). HPV DNA sequences were detected in 5 of 24 KS specimens, in 4 of 13 normal skin specimens from AIDS patients withoutKS and in 5 of 14 skin specimens of HIV-seronegative patients. For the first time, HPV types 6 and 33 were detected by PCR in KS. A higher proportion of HPV types 16/18 was found in AIDS-associated KS specimens, whereas HPV type 33 was seen more often in normal skin specimens of the control group. Apart from the known HPV types 16/18 described in KS, this study demonstrates also the presence of HPV 6 and 33 in this condition. © 1995 Wiley-Liss, Inc.     

Kaposi's disease and HHV8: a new model of virus-induced tumorigenesis

Kaposi's sarcoma (KS) is a skin disease characterised by spindle cells proliferation and neovascularisation which, in 1994, was associated with a new Gammaherpesvirinae, named human herpesvirus 8 (HHV8). The HHV8 genome, containing more than 140 kilobases, includes genes encoding structural proteins and enzymes, and some homologues to cellular genes which could have been captured in host cells during viral evolution. Several HHV8 proteins interfere with the host cellular cycle either by inhibiting apoptosis or by positive regulation of the cell cycle (viral cyclin or v-cyclin, v-bcl-2, v-FLIP). HHV8 also contains potential oncogenes (v-IRF and v-GPCR, which promote angiogenesis, in particular the secretion of VEGF) as well as homologues of human cytokines and chemokines (v-IL6, v-MIP). HHV8 is clearly associated with KS, multicentric Castleman disease and primary effusion lymphoma. Most of the cells are infected by latent virus, resulting in persistent infection of the lesions. Only a minority of infected cells yield infectious viral particles, and their role in the development of KS and other associated diseases has not been clearly established. The molecular mechanisms and cofactors involved in the physiopathology of this infection have yet to be identified.     

Epidemiological surveillance of the HIV/AIDS complex through the analysis of trends in the incidence of Kaposi's sarcoma in Cali,Colombia

Introduction:

The Kaposi''s sarcoma (KS) incidence has markedly changed in the general population since the onset of the AIDS epidemic in the eighties and after the introduction of the Highly Active Antiretroviral Therapy (HAART) in the nineties.

Objective:

To investigate incidence rate trends for Kaposi''s sarcoma before and during the (HIV/AIDS) epidemic in Cali, Colombia.

Methods:

Exploratory ecological study that included all Kaposi''s sarcoma cases identified by the Cali Cancer Registry from 1962-2007, and 12,887 cases of HIV/AIDS recorded in the Municipal Health Secretariat of Cali between 1986 and 2010. The joinpoint regression model was used to conduct the incidence rate analyses between the years 1962 and 2010.

Results:

A total of 349 KS cases were identified during the study period. Only 5.3% of the cases (n=20) were diagnosed in the pre-epidemic era (1963-1987), of these, 35% were women, and 90% of the tumors were located on the skin. In contrast, 94.7% of KS cases (n=329) were discovered after the emergence of HIV-AIDS. There was a significant decrease in the proportion of women (10.9%, p <0.001) and an increase in the frequency of tumors with an extra-cutaneous location (19.1%, p <0.01) compared to those cases diagnosed in the pre-epidemic era. Notification rates of HIV/AIDS have decreased since 2002 in both genders but KS incidence rates have decreased since 2004 in men only.

Conclusion:

The downward trend in the incidence of these diseases may be associated with factors that prevent the transmission of HIV infection or limit the spread of HIV in the community. Cancer registries represent a resource for timely, population-based surveil-lance of HIV-associated malignancies in Cali, Colombia.     

Detection of human herpes virus 8 DNA and sequence polymorphism in classical,epidemic, and iatrogenic Kaposi's sarcoma in South Africa

The aetiology and detection of human herpes virus type 8 (HHV-8) DNA sequences in Kaposi's sarcoma (KS) is a matter of intense investigation. We report on the detection of HHV-8 DNA and sequence polymorphism in different clinicopathological subtypes of cutaneous KS samples from South Africa. The diagnosis was confirmed by histological examination in all cases. Six patients had classic KS (CKS), 3 epidemic KS (EKS), and 3 iatrogenic KS (IKS). A nested polymerase chain reaction (PCR) assay was used to detect HHV-8 DNA in cell lysates, prepared from formalin fixed, paraffin embedded sections. We investigated polymorphism in the HHV-8 DNA using single-stranded conformational polymorphism (SSCP) analysis on the PCR products, followed by direct sequencing. HHV-8 DNA was detected in all the patients with KS, irrespective of the clinicopathological subtype. Direct sequencing was performed on 5 selected cases and showed single base pair substitutions in all. The spectrum of mutations was similar to those described previously. No correlation was found between the different types of KS and sequence variation. The results support the hypothesis that HHV-8 is strongly associated with different clinicopathological subtypes of KS and confirm the occurrence of HHV-8 in patients with CKS, EKS, and IKS in South Africa. J. Med. Virol. 52:168–172, 1997. © 1997 Wiley-Liss, Inc.     

A descriptive study of Kaposi's sarcoma in south Florida

A larger-than-expected incidence of Kaposi''s sarcoma in women is observed in south Florida. The possibility of a shift in cancer experience to groups previously considered at low risk (eg, women and blacks) or tumors (eg, Kaposi''s sarcoma) is suggested.     

Quantification of human herpesvirus 8 by real-time PCR in blood fractions of AIDS patients with Kaposi's sarcoma and multicentric Castleman's disease

Few studies have assessed human herpesvirus 8 (HHV8) viremia levels in different HHV8-related pathologies, using sensitive and reproducible molecular assays. Our objective was to compare the HHV8 DNA load in serial blood samples (collected every 3 months for 1 year) from acquired immunodeficiency syndrome (AIDS) patients with Kaposi's sarcoma (KS) and multicentric Castleman's disease (MCD). The HHV8 viral load was determined in both peripheral blood mononuclear cells (PBMC) and plasma fractions, using a competitive real-time polymerase chain reaction (PCR) assay developed in a LightCycler instrument (Roche Diagnostics). In six subjects with limited or extensive KS while on highly active antiretroviral therapy, the HHV8 DNA load was either undetectable (<50 copies/10(5) cells) or low (1,000 copies in at least one of the samples from the two subjects with both KS and MCD. HHV8 DNA was detected in plasma only when the cellular viral load was >10,000 copies/10(5) cells. After chemotherapy, the HHV8 DNA load became undetectable in the MCD patients despite no changes in CD4 T-cell counts or highly active antiretroviral therapy (HAART) regimens. These results suggest that the pathogenesis of the two HHV8-associated diseases (i.e., KS and MCD) might be different, as only the latter was associated with important viremia in our patients.     

Cytomegalovirus and human herpesvirus 8 DNA detection in peripheral blood monocytic cells of AIDS patients: correlations with the presence of Kaposi's sarcoma and CMV disease

To establish the effect of the presence in blood cells of cytomegalovirus (CMV) and human herpesvirus 8 (HHV8) DNA, two herpesviruses that are activated frequently in AIDS patients, were selected from the Amsterdam Cohort Studies on HIV/AIDS 181 PBMC samples from patients with and without Kaposi's sarcoma (KS), and with and without CMV-related disease. The viral loads of both HHV8 and CMV were determined by real-time PCR at the time of diagnosis of AIDS. There was no significant difference in prevalence and load for CMV between the KS and non-KS patients. The variable related most strongly to KS was the presence of HHV8 DNA in PBMCs, whilst CMV DNA was related to the development of CMV disease and shortened survival. The frequency of detection of HHV8 increased when the patient presented with more severe KS symptoms at diagnosis, but detection of HHV8 DNA did not influence survival. Therefore, HHV8 and CMV DNA measured in the blood of AIDS patients, are each related mainly to the associated disease, and have no additional predictive value in these patients.