Dextrin Sulphate and Fucoidan are Potent Inhibitors of HIV Infection in vitro

Two sulphated polysaccharides, fucoidan (a derivative of seaweed) and the newly synthesised dextrin sulphate, were tested for their ability to inhibit human immunodeficiency virus (HIV) infection in vitro in comparison to dextran sulphate and azidothymidine. They were found to be potent inhibitors of diverse strains of HIV-1 in a variety of human cell lines and in peripheral blood lymphocytes (PBL) using a range of assays, including cell-free and cell-to-cell spread of infection. The drugs did not adversely affect cell proliferation or protein metabolism of PBL. As dextrin sulphate is less potent than dextran sulphate in prolonging thrombin-induced fibrin clotting time, it merits further development as an antiviral agent.

Human Herpesvirus 8 Seroprevalence among Prostate Cancer Case Patients and Control Subjects

To investigate a possible association between human herpesvirus 8 (HHV-8) and prostate cancer, we evaluated HHV-8 seroprevalence in 2 case-control studies. HHV-8 antibodies were detected by immunofluorescence with cells expressing lytic viral proteins and by enzyme immunoassays with recombinant viral structural protein (K8.1) and latent protein (latency-associated nuclear antigen-1; open reading frame 73), respectively. HHV-8 seroprevalence tended to be lower in patients with prostate cancer than in control subjects, but there was no significant difference in either study. These data imply that HHV-8 is not a major prevalent cause of prostate cancer.

Absence of human T-cell lymphotropic virus type I and human foamy virus in thymoma

The cause of thymoma, a rare malignancy of thymic epithelial cells, is unknown. Recent studies have reported the detection of DNA from human T-cell lymphotropic virus type I (HTLV-I) and human foamy virus (HFV) in small numbers of thymoma tumours, suggesting an aetiologic role for these retroviruses. In the present study, we evaluated 21 US thymoma patients and 20 patients with other cancers for evidence of infection with these viruses. We used the polymerase chain reaction to attempt to amplify viral DNA from tumour tissues, using primers from the pol and tax (HTLV-I) and gag and bel1 (HFV) regions. In these experiments, we did not detect HTLV-I or HFV DNA sequences in any thymoma or control tissues, despite adequate sensitivity of our assays (one HTLV-I copy per 25 000 cells, one HFV copy per 7500 cells). Additionally, none of 14 thymoma patients evaluated serologically for HTLV I/II infection was positive by enzyme-linked immunoassay (ELISA), while five (36%) had indeterminate Western blot reactivity. In comparison, one of 20 US blood donors was HTLV-I/II ELISA positive, and nine (45%) donors, including the ELISA-positive donor, had indeterminate Western blot reactivity. Western blot patterns varied across individuals and consisted mostly of weak reactivity. In conclusion, we did not find evidence for the presence of HTLV-I or HFV in US thymoma patients.

Risk of malignant lymphoma associated with human herpesvirus-8: a case-control study in Spain

No overall increased risk of lymphoma associated with antibodies to human herpesvirus-8 was found in 526 lymphomas and 599 controls (odds ratio (OR)=1.04, 95% confidence interval (CI)=0.62–1.75); significant increases were noted for 19 lymphoplasmacytic lymphomas (OR=4.47, 95% CI=1.34–14.85) and nine low-grade lymphoma/lymphoma B-cell NOS (OR=5.82, 95% CI=1.07–31.73).

Multicenter comparison of serologic assays and estimation of human herpesvirus 8 seroprevalence among US blood donors

BACKGROUND

As part of assessing the possibility of transfusion transmission of human herpesvirus 8 (HHV-8 or Kaposi's sarcoma-associated herpesvirus), HHV-8 seroprevalence was estimated among US blood donors, the performance of HHV-8 serologic tests was compared, and the presence of HHV-8 DNA was tested for in donated blood.

STUDY DESIGN AND METHODS

Replicate panels of 1040 plasma specimens prepared from 1000 US blood donors (collected in 1994 and 1995) and 21 Kaposi's sarcoma patients were tested for antibodies to HHV-8 in six laboratories. HHV-8 PCR was performed on blood samples from 138 donors, including all 33 who tested seropositive in at least two laboratories and 22 who tested positive in at least one.

RESULTS

The estimated HHV-8 seroprevalence among US blood donors was 3.5 percent (95% CI, 1.2%-9.8%) by a conditional dependence latent-class model, 3.0 percent (95% CI, 2.0%-4.6%) by a conditional independence latent-class model, and 3.3 percent (95% CI, 2.3%-4.6%) by use of a consensus-derived gold standard (specimens positive in two or more laboratories); the conditional dependence model best fit the data. In this model, laboratory specificities ranged from 96.6 to 100 percent. Sensitivities ranged widely, but with overlapping 95 percent CIs. HHV-8 DNA was detected in blood from none of 138 donors evaluated.

CONCLUSIONS

Medical and behavioral screening does not eliminate HHV-8-seropositive persons from the US blood donor pool, but no viral DNA was found in donor blood. Further studies of much larger numbers of seropositive individuals will be required to more completely assess the rate of viremia and possibility of HHV-8 transfusion transmission. Current data do not indicate a need to screen US blood donors for HHV-8.

Prevalence and distribution of HHV-8 in different subpopulations, with and without HIV infection, in Spain

OBJECTIVE

To estimate the seroprevalence of HHV-8 in several Spanish subpopulations with different risk levels of acquiring HIV-1 infection and from different geographical regions.

DESIGN

Cross-sectional seroprevalence study.

METHODS

A total of 1699 serum samples from blood donors (613), children under the age of 12 years (100), injecting drug users (IDU) (382), heterosexuals attending a sexually transmitted disease (STD) clinic (273) and homosexual men attending a STD clinic or a HIV-based hospital unit (331) were analysed for anti-HHV-8 antibodies. The presence of antibodies against HHV-8 was tested with an indirect immunofluorescence assay (IFA). A subsample of HHV-8-positive samples was also tested for antibody titre against HHV-8.

RESULTS

The overall seroprevalence of antibodies against HHV-8 for the blood donor population was 6.5% (7.0% in Andalusia, 8.0% in Catalonia and 4.5% in the Basque Country). None of the children tested positive for HHV-8. The HHV-8 prevalence was 86.7% in HIV-positive homosexual men and 28.0% in HIV-negative homosexual men (P < 0.001). Of heterosexual men attending STD clinics, 17.2% tested positive for HHV-8; 11.5% of IDU tested positive for HHV-8. HHV-8 antibody titres by groups parallel the distribution of HHV-8 prevalence. No association between HHV-8 antibody titres and CD4 cell count or HIV viral load was identified.

CONCLUSIONS

The HHV-8 prevalence among blood donors in Spain is higher than in Northern Europe and the USA, but is similar to that in Northern Italy. The distribution of HHV-8 is compatible with a sexually transmitted agent. The distribution of HHV-8 correlates with that of Kaposi's sarcoma but factors other than HHV-8 seem to explain the Kaposi sarcoma distribution.

Latent class analysis of human herpesvirus 8 assay performance and infection prevalence in sub-saharan Africa and Malta

Human herpesvirus 8 (HHV-8) is thought to be highly prevalent in Mediterranean countries and sub-Saharan Africa, where it causes Kaposi's sarcoma in a small proportion of infected immunocompetent persons. However, the lack of serological tests with established accuracy has hindered our understanding of the prevalence, risk factors and natural history of HHV-8 infection. We tested 837 subjects from Congo, Botswana (mostly young adults) and Malta (elderly adults), using an immunofluorescence assay and 2 enzyme immunoassays (EIAs, to viral proteins K8.1 and orf65). Each assay found HHV-8 seroprevalence to be high (49-87%) in the African populations and generally lower (9-54%) in Malta. However, there was only modest agreement among tests regarding which subjects were seropositive (3-way kappa, 0.05-0.34). We used latent class analysis to model this lack of agreement, estimating each test's sensitivity and specificity and each population's HHV-8 prevalence. Using this approach, the K8.1 EIA had consistently high sensitivity (91-100%) and specificity (92-100%) across populations, suggesting that it might be useful for epidemiological studies. Compared with the K8.1 EIA, both the immunofluorescence assay and the orf65 EIA had more variable sensitivity (80-100% and 58-87%, respectively) and more variable specificity (57-100% and 48-85%, respectively). HHV-8 prevalence was 7% among elderly Maltese adults. Prevalence was much higher (82%) in Congo, consistent with very high Kaposi's sarcoma incidence there. Prevalence was also high in Botswana (87% in Sans, an indigenous group, and 76% in Bantus), though Kaposi's sarcoma is not common, suggesting that additional co-factors besides HHV-8 are needed for development of Kaposi's sarcoma.

Activity of thalidomide in AIDS-related Kaposi's sarcoma

PURPOSE

To assess the toxicity and activity of oral thalidomide in Kaposi's sarcoma (KS) in a phase II dose-escalation study.

PATIENTS AND METHODS

Human immunodeficiency virus (HIV)-seropositive patients with biopsy-confirmed KS that progressed over the 2 months before enrollment received an initial dose of 200 mg/d of oral thalidomide in a phase II study. The dose was increased to a maximum of 1,000 mg/d for up to 1 year. Anti-HIV therapy was maintained during the study period. Toxicity, tumor response, immunologic and angiogenic factors, and virologic parameters were assessed.

RESULTS

Twenty patients aged 29 to 49 years with a median CD4 count of 246 cells/mm(3) (range, 14 to 646 cells/mm(3)) were enrolled. All patients were assessable for toxicity, and 17 for response. Drowsiness in nine and depression in seven patients were the most frequent toxicities observed. Eight (47%; 95% confidence interval [CI], 23% to 72%) of the 17 assessable patients achieved a partial response, and an additional two patients had stable disease. Based on all 20 patients treated, the response rate was 40% (95% CI, 19% to 64%). The median thalidomide dose at the time of response was 500 mg/d (range, 400 to 1,000 mg/d). The median duration of drug treatment was 6.3 months, and the median time to progression was 7.3 months.

CONCLUSION

Oral thalidomide was tolerated in this population at doses up to 1,000 mg/d for as long as 12 months and was found to induce clinically meaningful anti-KS responses in a sizable subset of the patients. Additional studies of this agent in KS are warranted.

Human herpesvirus 8 in Brazilian Amerindians: a hyperendemic population with a new subtype

Human herpesvirus 8 (HHV-8) epidemiology in Brazilian Amerindians was studied. Use of an immunofluorescence (IFA) test for latent antibody demonstrated that the prevalence of HHV-8 in 781 Amerindians of diverse tribes (overall, 53% prevalence) was not related to language group or sex but rather increased gradually from 41% in children <10 years of age to 65% in adults >/=30 years of age. In IFA-positive subjects, HHV-8 DNA was detected in 3 (16%) of 19 mononuclear cell samples from peripheral blood and in 1 of 16 saliva samples. The sequences of conserved ORF22 and K6 genes were typical of HHV-8, but the variable K1 gene sequences were only 70%-75% identical to other known HHV-8 strains. Thus, a new HHV-8 subtype, E, is hyperendemic in Brazilian Amerindians, although Kaposi's sarcoma has not been reported. Transmission is probably oral rather than sexual. The limited genetic pool in isolated groups may permit more frequent transmission of a virus with a low prevalence in heterogeneous populations.

Identifying human herpesvirus 8 infection: performance characteristics of serologic assays

Epidemiologic studies of infection with the oncogenic human herpesvirus 8 (HHV-8) depend on serologic methods to diagnose infection. However, optimal strategies for identifying HHV-8 infection remain undefined. We therefore evaluated four enzyme-linked immunoassays (EIAs) and one immunofluorescence assay (IFA) using sera from 87 individuals with the prototype HHV-8 disease, Kaposi's sarcoma (KS), and 210 participants in a hemophilia study (who were presumed not to be infected with HHV-8). Assays performed reasonably well in distinguishing between infected and uninfected persons, with receiver operator curve areas between 0.86 and 0.96. Nonetheless, IFA had only 86% sensitivity and 88% specificity, and no EIA simultaneously had sensitivity and specificity above 90% for any of the optical density (OD) cutpoints used to define seropositivity. Some assays were markedly less sensitive with diluted KS sera, suggesting that they poorly identify low-titer antibodies present in asymptomatic infection. We also developed a classification tree that categorized individuals as seropositive if they had OD > 2.00 on recombinant K8.1 protein EIA or if they had both K8.1 OD between 0.51 and 2.00 and positive IFA results; this strategy had between 80% and 90% sensitivity and 95% and 100% specificity. Overall, assays performed adequately for use in most epidemiologic investigations, but wider applications will require improved tests.

Detection of antibodies to human herpesvirus 8 in Italian children: evidence for horizontal transmission

Human herpesvirus 8 (HHV-8), also known as Kaposi's sarcoma associated herpesvirus (KSHV), has been shown to be the causative agent for Kaposi's sarcoma (KS) and to be more prevalent in populations or risk groups at increased risk for KS. HHV-8 infection is rare in children from the US and the UK, but has been reported in African children. In this study we examine HHV-8 infection in children from Italy, a country with an elevated prevalence of HHV-8 in adults and high socio-economic conditions.

Serologic evidence of human herpesvirus 8 transmission by homosexual but not heterosexual sex

Epidemiologic studies link Kaposi's sarcoma with a sexually transmitted agent. Human herpesvirus 8 (HHV-8) is likely to be that agent, but routes of transmission are poorly described. A seroepidemiologic study was conducted to determine whether HHV-8 is transmitted sexually between heterosexuals. Sera from 2718 patients attending a sexually transmitted disease (STD) clinic were tested for antibodies to HHV-8 and herpes simplex virus type 2 (HSV-2). Information on sex partners in the previous 12 months and past STDs were obtained by questionnaire. Relationships between possible risk factors and HHV-8 infection were assessed by logistic regression. Overall, seroprevalence of HHV-8 was 7.3%. Independent risk factors for HHV-8 in the whole group were homo/bisexuality and birth in Africa and, among homo/bisexual men, a history of syphilis and HSV-2 and human immunodeficiency virus seropositivity. Among heterosexuals there was no evidence for sexual transmission; the only independent risk factor for HHV-8 seropositivity was birth in Africa.

Variability and evolution of Kaposi's sarcoma-associated herpesvirus in Europe and Africa. International Collaborative Group

OBJECTIVE

To study the evolution of Kaposi's sarcoma-associated herpesvirus (KSHV) or human herpesvirus type 8 in Europe and Africa.

DESIGN AND METHODS

PCR and sequence analysis of the variable viral membrane glycoprotein gene K1 in 58 tumour and peripheral blood samples from patients with AIDS-related Kaposi's sarcoma (KS), 'classic' (HIV-negative) KS, transplant KS, Multicentric Castleman's Disease, other lymphoproliferative disorders, and healthy KSHV-infected individuals from the UK, Denmark, Sweden, Italy, Spain, Iceland, The Faroe Islands, Greece, The Gambia and Uganda.

RESULTS

Three major groups of K1 sequences were found: A, B and C, as defined previously. The K1 gene has evolved, both within and between these three groups, under positive selection. KSHV group B strains predominate in Africa and are more distant from groups A and C, found in Europe, than A and C are from each other. Within group C two subgroups, C' and C", can be identified. Subgroup C" is more closely related to group A in a region of the K1 protein and appears to be phylogenetically close to the branchpoint between A and C. Group A and C strains are currently found in both HIV-1-infected and -uninfected Europeans, and were already present in Europe before the start of the AIDS epidemic. We found some examples of closely related K1 sequences in Italy and Denmark, but in general KSHV strains in Europe did not cluster geographically.

CONCLUSION

KSHV strains in East and West Africa are closely related but phylogenetically distant from those in Europe. The two major KSHV groups in Europe are more closely related, with some strains adopting an intermediate phylogenetic position. In Europe, KSHV strains may have been disseminated at least several decades ago. Variability in the K1 region is driven by selection and does not correlate with different KSHV-related pathologies or geographic regions where clinically more aggressive HIV-negative KS ('endemic' KS) is more common.

Antibodies against human herpesvirus 8 in black South African patients with cancer

BACKGROUND

Infection with human herpesvirus 8 (HHV-8) has been consistently linked to Kaposi's sarcoma, but its mode of transmission, association with other cancers, and interaction with the human immunodeficiency virus type 1 (HIV-1) are largely unknown.

METHODS

Between January 1992 and December 1997, we interviewed 3591 black patients with cancer in Johannesburg and Soweto, South Africa. Blood was tested for antibodies against HIV-1 and HHV-8 in 3344 of the patients. Antibodies against HHV-8 were detected with an indirect immunofluorescence assay. The intensity of the fluorescent signal correlated well with the titers of antibodies (P<0.001). The relations among the presence of anti-HHV-8 antibodies, sociodemographic and behavioral factors, type of cancer, and the presence or absence of coexistent HIV infection were examined with the use of unconditional logistic-regression models.

RESULTS

Among the 3293 subjects with cancers other than Kaposi's sarcoma, the standardized seroprevalence of antibodies against HHV-8 was 32 percent, which did not differ significantly from the standardized seroprevalence among black blood donors. Among these 3293 patients, the prevalence of antibodies against HHV-8 increased with increasing age (P<0.001) and an increasing number of sexual partners (P=0.05) and decreased with increasing years of education (P=0.007); it was not strongly associated with HIV-1 infection. Anti-HHV-8 antibodies were more frequent among black than white blood donors (P<0.001). Among the 51 patients with Kaposi's sarcoma, the standardized seroprevalence of antibodies against HHV-8 was 83 percent, significantly higher than the prevalence among those without Kaposi's sarcoma (P<0.001). For 16 other specific types of cancer, including multiple myeloma (108 cases) and prostate cancer (202 cases), the variation in the standardized seroprevalence of antibodies against HHV-8 was not remarkable. At a given intensity of fluorescence of anti-HHV-8 antibodies, Kaposi's sarcoma was more frequent among HIV-1-positive patients than among those who were HIV-1-negative (P<0.001).

CONCLUSIONS

Among black patients with cancer in South Africa, the seroprevalence of anti-HHV-8 antibodies is high and is specifically associated with Kaposi's sarcoma, particularly at high titers.

Human herpesvirus 8: seroepidemiology among women and detection in the genital tract of seropositive women

An indirect IFA to detect antibodies against latent nuclear antigens of human herpesvirus 8 (HHV-8) was used to determine the prevalence of HHV-8 antibodies in 169 women attending a sexually transmitted diseases clinic and a human immunodeficiency virus (HIV) clinic at a London hospital. Nested polymerase chain reaction was used to detect HHV-8 DNA in 93 blood samples and 89 cervical brush scrapes (CBS). Another 96 CBS from women attending a colposcopy clinic were also analyzed. The overall seroprevalence of HHV-8 was 18.3%. The seroprevalence was higher among women born in Africa (24.7%) than among women born elsewhere (11.5%; P=.06) and was independent of HIV serostatus. HHV-8 DNA was detected in 3 CBS and 6 peripheral blood samples from 11 HHV-8-seropositive women but not in CBS from 78 seronegative women, 96 women from the colposcopy clinic, or in blood samples from 82 seronegative women.

Kaposi's sarcoma herpesvirus as a new paradigm for virus-induced oncogenesis

Seroepidemiologic studies show that Kaposi's sarcoma herpesvirus (KSHV) is more prevalent in those populations at higher risk to develop Kaposi's sarcoma (KS). Anti-KSHV antibody titer is also higher in those who develop KS. KSHV is a sexually transmitted disease among homosexual men, but other routes of transmission appear to be more important in Africa and Mediterranean Europe. KSHV encodes numerous cellular homologues that might be involved in KS and lymphoma pathogenesis. The characterization of these homologues provides insight into the functions of their cellular counterparts. KSHV is also unique among human herpesviruses by encoding chemokine homologues. Unlike cellular MIP1 alpha and RANTES, KSHV-chemokines are promiscuous in their receptor usage and do induce angiogenesis. They may also play a role in preventing central nervous system diseases in HIV-positive individuals.

Human herpesvirus type 8 and Kaposi's sarcoma

Kaposi's sarcoma-associated herpesvirus or human herpesvirus type 8 (HHV-8) is present in all forms of Kaposi's sarcoma (KS) as well as in primary effusion lymphomas and some cases of Castleman's disease. In KS tissues, HHV-8 is present in endothelial and spindle cells. Current serologic tests suggest that HHV-8 is predominantly found in those at risk of KS and is not as widespread as most other human herpesviruses. HHV-8 encodes various proteins that may play a role in promotion of cellular growth, including cyclin- and G-coupled protein receptor homologues, and anti-apoptotic proteins, including Bcl-2, IL-6 (i.e., interleukin 6), and FLIP (i.e., FLICE inhibitory protein) homologues. In addition, HHV-8 encodes two macrophage inflammatory-like proteins with anti-human immunodeficiency virus and angiogenic potential.

Interassay correlation of human herpesvirus 8 serologic tests. HHV-8 Interlaboratory Collaborative Group

To standardize human herpesvirus 8 (HHV-8) antibody assays for application to asymptomatic infection, a blinded comparison was done of seven immunofluorescence assays and ELISAs. Five experienced laboratories tested a serum panel from 143 subjects in 4 diagnostic groups. Except for a minor capsid protein ELISA, the other six tests detected HHV-8 antibodies most frequently in classic (80%-100%) and AIDS-related (67%-91%) Kaposi's sarcoma, followed by human immunodeficiency virus-seropositive patients (27%-60%), and least frequently in healthy blood donors (0-29%). However, these six assays frequently disagreed on individual sera, particularly for blood donor samples. Current HHV-8 antibody tests have uncertain accuracy in asymptomatic HHV-8 infection and may require correlation with viral protein or nucleic acid detection. Antibody assays are useful for epidemiologic investigations, but the absolute prevalence of HHV-8 infection in the United States cannot yet be determined.

Limited transmission of Kaposi's sarcoma-associated herpesvirus in cultured cells

Kaposi's sarcoma-associated herpesvirus (KSHV) (also called human herpesvirus 8) is a novel gammaherpesvirus strongly implicated in the pathogenesis of Kaposi's sarcoma. Although virions can be produced in high yield from latently infected B-cell lines treated with phorbol esters, little is known about the infectivity of such virus, and efficient serial propagation of KSHV has been problematic. Here we report on the infectivity of KSHV produced from phorbol-induced BCBL-1 cells, employing an assay based on the detection of a spliced late mRNA by a sensitive reverse transcriptase PCR (RT-PCR) method. The results of this study confirm previous observations that 293 cells are susceptible to viral infection; however, infection with BCBL-1-derived virus is inefficient and the pattern of viral gene expression in infected cells may not fully reproduce that of authentic lytic infection. In keeping with this finding, serial propagation of BCBL-1-derived virus could not be demonstrated on 293 cells. Eleven of 38 other cell lines tested also supported KSHV infection, as judged by this RT-PCR assay, including cells of B-cell, endothelial, epithelial, and fibroblastic origin; however, in all cases, infection proceeded at or below the levels observed in 293 cells.

A broad range of chemokine receptors are used by primary isolates of human immunodeficiency virus type 2 as coreceptors with CD4

Like human immunodeficiency virus type 1 (HIV-1) and simian immunodeficiency virus (SIV), HIV-2 requires a coreceptor in addition to CD4 for entry into cells. HIV and SIV coreceptor molecules belong to a family of seven-transmembrane-domain G-protein-coupled receptors. Here we show that primary HIV-2 isolates can use a broad range of coreceptor molecules, including CCR1, CCR2b, CCR3, CCR4, CCR5, and CXCR4. Despite broad coreceptor use, the chemokine ligand SDF-1 substantially blocked HIV-2 infectivity of peripheral blood mononuclear cells, indicating that its receptor, CXCR4, was the predominant coreceptor for infection of these cells. However, expression of CXCR4 together with CD4 on some cell types did not confer susceptibility to infection by all CXCR4-using virus isolates. These data therefore indicate that another factor(s) influences the ability of HIV-2 to replicate in human cell types that express the appropriate receptors for virus entry.

Kaposi's sarcoma in the Gambia, West Africa is less frequent in human immunodeficiency virus type 2 than in human immunodeficiency virus type 1 infection despite a high prevalence of human herpesvirus 8

OBJECTIVES

To investigate the distribution of Kaposi's sarcoma (KS) cases in patients with human immunodeficiency virus types 1 and 2 (HIV-1 and HIV-2) infection in the Gambia; to document the prevalence of human herpesvirus 8 (HHV-8) infection in various population groups in the Gambia.

STUDY DESIGN/METHODS

A retrospective analysis of KS cases in hospital records at the Medical Research Council (MRC) hospital was performed, along with a cross-sectional survey of HHV-8 prevalence in hospital-based and community-based study population with polymerase chain reaction (PCR) and serologic assays.

RESULTS

After adjusting for gender and CD% at the first visit, HIV-1-positive patients were 12.4 times more likely to have KS than were HIV-2-positive patients. The prevalence of antibodies to HHV-8 and the HHV-8 genome was high in both HIV-1-positive and HIV-2-positive patients without KS. The prevalence of antibodies was also high in pregnant women who were HIV-1-positive, HIV-2-positive, or HIV-negative (73%, 83%, and 79%, respectively).

CONCLUSIONS

HHV-8 infection is widespread in the Gambia. In addition to immunosuppression and HHV-8 infection, other cofactors specifically related to HIV-1 rather than HIV-2 appear to be involved in the development of KS.

Association of Kaposi's sarcoma associated herpesvirus (KSHV) DNA in bronchoalveolar lavage fluid of HIV infected individuals with bronchoscopically diagnosed tracheobronchial Kaposi's sarcoma

OBJECTIVES

To determine the frequency of detection of Kaposi's sarcoma associated herpesvirus (KSHV), also known as human herpesvirus (HHV) type 8, DNA in bronchoalveolar lavage (BAL) fluid from HIV infected individuals with and without KS and to compare this with the detection rate in peripheral blood. Also to identify whether KSHV was associated with specific cell types in lavage fluid.

METHODS

Nested PCR was used to detect KSHV DNA in BAL fluid from 41 consecutive individuals with Kaposi's sarcoma (KS) and in 41 controls with similar CD4 lymphocyte counts. Semiquantification of viral DNA was by end point titration. A positive cell sorting selection procedure was used to isolate specific BAL fluid cell types.

RESULTS

KSHV DNA was detected in BAL fluid from 24 of 29 (83%) individuals with a bronchoscopic diagnosis of tracheobronchial KS. None was detected in 12 individuals with only cutaneous KS, or in 41 matched controls without KS. In five, KSHV DNA was detected in the cell depleted and cellular fractions of BAL fluid and in 1/5 in the CD14 (macrophage) fractions. None was detected in the CD19 (B lymphocyte) or CD4/CD8 (T lymphocyte) fractions.

CONCLUSIONS

There was a clear association between the diagnosis of tracheobronchial KS and detection of KSHV DNA in BAL fluid. The cell type supporting KSHV in the respiratory tract is not CD 19 positive and has yet to be conclusively identified.

Identification of a major latent nuclear antigen, LNA-1, in the human herpesvirus 8 genome

OBJECTIVES

Human herpesvirus 8 (HHV-8) is strongly associated with all forms of Kaposi's sarcoma (KS) and with primary effusion lymphomas (PEL). KS patients' sera are immunoreactive against discrete nuclear localizing antigens in PEL cell lines. This study sought to identify and characterize these nuclear localizing proteins.

STUDY DESIGN/METHODS

KS patients' sera were used to screen a cDNA expression library derived from a PEL cell line (BCP-1) latently infected with HHV-8.

RESULTS

An HHV-8-specific cDNA clone was isolated. It encoded one partial and two complete open reading frames (ORFs): ORF 73, ORF 72 (v-cyclin), and K13, respectively. The immunodominant epitope was mapped to the C-terminal domain of ORF 73. Analysis with the KS patients' sera of HEK 293 cells transfected with a clone encompassing the complete coding region of ORF 73, ORF 72, and K13 gave a nuclear immunofluorescence pattern similar to that observed in BCP-1 cells. Western blot analysis with KS patients' sera of transfected HEK 293 cells revealed an immunoreactive protein of 220 to 230 kD that was similar to that observed previously in PEL cell lines. After induction of lytic replication of HHV-8 in BCP-1 cells with n-butyrate, we observed a major reduction in the expression of an ORF 73-specific 6.6-kb mRNA, indicating that this region is under latent control.

CONCLUSIONS

These data identify a region of HHV-8 encoding for a major immunoreactive latent nuclear antigen (LNA-1), analogous to the Epstein-Barr virus latent nuclear antigens.

The evaluation of velopharyngeal function using flexible nasendoscopy

Nasendoscopy is an essential tool in assessing the dynamic function and structure of the velopharyngeal sphincter during speech and swallowing. Flexible fibre-optic nasendoscopy has been used by the cleft palate team at Withington Hospital, Manchester since 1989. Seventy-six patients were referred between 1989 and 1994 for evaluation of velopharyngeal function during speech. Flexible nasendoscopic evaluation was attempted in 50 patients, and successfully carried out in 43 patients. The age range was four years to 77 years (mean 21 years). The patients were divided into two groups: Group 1 consisting of patients with cleft palate and Group 2 comprised of patients with non-overt cleft palate-related velopharyngeal dysfunction of various aetiologies; such as, submucous cleft, post-tonsillectomy, post-adenoidectomy, neurological and post-traumatic. Based on the findings on nasendoscopy, videofluoroscopy and clinical speech/voice analysis the following treatment options were recommended: 17 (40 per cent) for pharyngoplasty, five (11 per cent) for revision pharyngoplasty, 15 (35 per cent) for speech therapy, four for an obturator and one for tonsillectomy. Two previously undetected submucous clefts were diagnosed.

Etiology of AIDS-related Kaposi's sarcoma and lymphoma

Kaposi's sarcoma (KS) and non-Hodgkin's lymphomas (NHL) are common consequences of HIV infection. These tumours appear to be precipitated by herpesviruses. Epstein-Barr virus (EBV) is implicated as a cause of up to 50% of systemic NHLs and up to 100% of central nervous system lymphomas in patients with AIDS. KS may be a consequence of the newly identified gamma-herpesvirus KSHV (KS-associated herpesvirus or HHV-8). This herpesvirus is found in all KS biopsies from different epidemiologic forms of this disease. KSHV is also implicated in the pathogenesis of a rare form of B cell lymphoma called body-cavity based lymphoma or primary effusion lymphoma (PEL).

Detection of human herpesvirus 8 DNA in semen from HIV-infected individuals but not healthy semen donors

OBJECTIVE

To ascertain the prevalence of Kaposi's sarcoma-associated herpesvirus (KSHV), also known as human herpesvirus (HHV) type 8, and cytomegalovirus (CMV) DNA in semen was investigated.

METHODS

Amplification by nested polymerase chain reaction was used to detect viral DNA sequences in samples from 24 HIV-infected gay men, 15 of them with Kaposi's sarcoma (KS), and 115 healthy donors.

RESULTS

Six of the 24 HIV-infected patients had detectable HHV-8 DNA in their semen: three of the 15 patients with KS and three of the nine patients without KS. CMV DNA was detected in 20 semen samples from HIV-infected patients. None of the semen samples from healthy donors had detectable HHV-8 DNA and rates of CMV DNA detection were low (3%).

CONCLUSIONS

The study demonstrates the presence of HHV-8 in semen from HIV-infected individuals with, or at risk, of developing KS and the potential for sexual transmission of the virus. We found no evidence of HHV-8 in the semen of HIV-uninfected donors.

Prevalence of Kaposi's sarcoma associated herpesvirus infection measured by antibodies to recombinant capsid protein and latent immunofluorescence antigen

BACKGROUND

Kaposi's sarcoma-associated herpesvirus (KSHV), also known as human herpesvirus 8, may be the infectious cause of KS. Its prevalence in the general population, on the basis of detection of the virus genome, is controversial. To investigate the seroprevalence, we measured antibodies to a recombinant capsid-related (lytic cycle) KSHV antigen and a latent antigen complex.

METHODS

We selected potentially immunoreactive capsid-related proteins of KSHV by expressing them as recombinant proteins and testing them in western blot assays. We used a truncated recombinant protein encoded by KSHV open reading frame 65 (orf 65) to develop a diagnostic enzyme-linked immunosorbent assay (ELISA) and tested sera from HIV-infected individuals with KS, HIV-uninfected patients with "classic" KS, other HIV risk groups, and blood donors. We also compared the antibody response to this capsid-related protein to the response to latent antigen(s) in an immunofluorescence assay.

FINDINGS

77/92 (84%) sera from KS patients reacted with the KSHV orf 65 protein and 84/103 (81.5%) reacted with KSHV latent antigen(s). The dominant immunogenic region of orf 65 is within the carboxyterminal 80 aminoacids, a region with little sequence similarity to the related Epstein-Barr virus, suggesting that orf 65 is a KSHV specific antigen. Only three sera from patients with haemophilia (1/84) or from intravenous drug users (2/63) had KSHV specific antibodies in the orf 65 assay whereas none of these sera reacted with latent antigen. Antibodies to KSHV were also infrequently found in UK and US blood donors by either assay (UK, 3/174 with orf 65 and 4/150 with latent antigen; US, 6/117 with orf 65 and 0/117 with latent antigen). They were more common among HIV-infected gay men without KS (5/16 by orf 65 ELISA, 10/33 by IFA), HIV-uninfected STD clinic attenders (14/166 by IFA), and Ugandan HIV-uninfected controls (6/17 by orf 65 ELISA, 9/17 by IFA). Antibody reactivity to the orf 65 protein (ELISA) and to latent antigen(s) (IFA) was concordant in 89% of 462 sera tested but reactive blood donor sera were discordant in both assays. Four AIDS-KS sera were unreactive in both assays.

INTERPRETATION

The distribution of antibodies to both a capsid-related recombinant protein and latent antigen(s) of KSHV strongly supports the view that infection with this virus is largely confined to individuals with, or at increased risk for, KS. However, infection with KSHV does occur, rarely, in the general UK and US population and is more common in Uganda. Antibodies to latent antigen(s) or to orf 65 encoded capsid protein will not detect all cases of KSHV infection, and a combination of several antigens will probably be required for accurate screening and confirmatory assays.

Kaposi's sarcoma-associated herpesvirus and Kaposi's sarcoma in Africa. Uganda Kaposi's Sarcoma Study Group

BACKGROUND

Endemic Kaposi's sarcoma (KS) is a clinically and epidemiologically distinct human immunodeficiency virus negative form of KS occurring in Africa. Kaposi's sarcoma is now the most frequently reported cancer in some areas of Africa.

OBJECTIVE

To determine if a KS-associated herpesvirus (KSHV) is present in both endemic HIV-seronegative and HIV-seropositive KS lesions from African patients.

METHODS

Paraffin-embedded tissue specimens from Ugandan patients with KS and non-KS tumor control patients attending a university-based oncology clinic were examined in a blinded case-control study. Tissue DNA specimens were examined for detectable KSHV genome by nested polymerase chain reaction performed at two independent laboratories.

RESULTS

We identified KSHV in 17 (85%) of 20 KS tissue specimens from HIV-seronegative patients and 22 (92%) of 24 KS tissue specimens from HIV-infected persons. Kaposi's sarcoma lesions from four HIV-infected persons and four HIV-seronegative persons were positive for KSHV. Unlike previous studies in North America and Europe, three (14%) of 22 non-KS cancer control patients' tissue specimens were also positive for KSHV that resulted in an overall odds ratio of 49.2 (95% confidence interval, 9.1 to 335) for detecting KSHV in KS lesions from patients in Uganda.

CONCLUSION

As in North America and Europe, KSHV infection is strongly associated with both HIV-seropositive and HIV-seronegative KS in Africa. However, it is likely that infection with this virus is more highly prevalent in Uganda.

Detection of Kaposi sarcoma associated herpesvirus in peripheral blood of HIV-infected individuals and progression to Kaposi's sarcoma

Kaposi sarcoma-associated herpesvirus (KSHV) is consistently found in biopsy samples from patients with AIDS-related and "classical" Kaposi's sarcoma (KS). Although highly suggestive of a causal role of KSHV in the pathogenesis of KS, this observation does not exclude the possibility that KSHV, like other herpesviruses, is widely distributed and is a mere "passenger" in these lesions. Here we report that KSHV was detectable in peripheral blood mononuclear cells of 24/46 (52%) of KS patients, but in none of 134 blood donors or 26 HIV-uninfected hospital controls. KSHV detection increased with immunosuppression, as shown by a correlation with a reduced number of CD4-positive T-cells. Moreover, KSHV detection in peripheral blood cells of HIV-infected individuals without KS predicted the subsequent appearance of KS lesions. 143 patients who did not have KS at the time of their first (or only) blood sample were followed up for a median of 30 months. Of the 11 who had been KSHV positive 6 developed KS compared with only 12 out of 132 who were KSHV negative. These findings are compatible with a causative role of KSHV in KS. KSHV was rarely detected in sputum and throat swabs of HIV-infected patients, providing a potential explanation for the apparently limited spread of this virus.

HIV-specific cytotoxic T-cells in HIV-exposed but uninfected Gambian women

A crucial requirement in the rational design of a prophylactic vaccine against the human immunodeficiency virus (HIV) is to establish whether or not protective immunity can occur following natural infection. The immune response to HIV infection is characterized by very vigorous HIV-specific cytotoxic T-lymphocyte (CTL) activity. We have identified four HIV-1 and HIV-2 cross-reactive peptide epitopes, presented to CTL from HIV-infected Gambians by HLA-B35 (the most common Gambian class I HLA molecule). These peptides were used to elicit HIV-specific CTLs from three out of six repeatedly exposed but HIV-seronegative female prostitutes with HLA-B35. These women remain seronegative with no evidence of HIV infection by polymerase chain reaction or viral culture. Their CTL activity may represent protective immunity against HIV infection.

A measles virus isolate from a child with Kawasaki disease: sequence comparison with contemporaneous isolates from 'classical' cases

We examined the relationship between a measles virus isolate from a child with Kawasaki disease and two contemporaneous wild-type isolates from children with 'classical' measles and the Schwarz vaccine strain. Sequence analysis of 3118 bp from the nucleoprotein, matrix, fusion and haemagglutinin genes of each virus revealed that the isolate from the child with Kawasaki disease was not related to measles vaccine strains and did not contain any of the marked abnormalities previously found in subacute sclerosing panencephalitis isolates, but was more akin to wild-type isolates currently circulating in the U.K. A comparison of our sequences with those obtained from earlier wild-type U.K. isolates suggests significant evolution of measles virus in the U.K. over the last decade.