The aims of the present study were to determine the prevalence of human herpesvirus type 8 (HHV-8) in HIV-positive Brazilian patients with (HIV+/KS+) and without Kaposi's sarcoma (HIV+/KS-) using PCR and immunofluorescence assays, to assess its association with KS disease, to evaluate the performance of these tests in detecting HHV-8 infection, and to investigate the association between anti-HHV-8 antibody titers, CD4 counts and staging of KS disease. Blood samples from 66 patients, 39 HIV+/KS+ and 27 HIV+/KS-, were analyzed for HHV-8 viremia in peripheral blood mononuclear cells by PCR and HHV-8 antigenemia for latent and lytic infection by immunofluorescence assay. Positive samples for latent nuclear HHV-8 antigen (LNA) antibodies were titrated out from 1/100 to 1/409,600 dilution. Clinical information was collected from medical records and risk behavior was assessed through an interview. HHV-8 DNA sequences were detected by PCR in 74.3% of KS+ patients and in 3.7% of KS- patients. Serological assays were similar in detecting anti-LNA antibodies and anti-lytic antigens in sera from KS+ patients (79.5%) and KS- patients (18.5%). HHV-8 was associated with KS whatever the method used, i.e., PCR (odds ratio (OR) = 7.4, 95% confidence interval (CI) = 2.16-25.61) or anti-LNA and anti-lytic antibodies (OR = 17.0, 95%CI = 4.91-59.14). Among KS+ patients, HHV-8 titration levels correlated positively with CD4 counts (rho 0.48, P = 0.02), but not with KS staging. HHV-8 is involved in the development of KS in different geographic areas worldwide, as it is in Brazil, where HHV-8 is more frequent among HIV+ patients. KS severity was associated with immunodeficiency, but no correlation was found between HHV-8 antibody titers and KS staging.

Background: Epidemiologic studies have indicated that human herpesvirus 8 is implicated in the development of Kaposi sarcoma in different geographic areas worldwide.Goal: To provide information on the prevalence of human herpesvirus 8 in Brazil and its association with Kaposi sarcoma.Study Design: An immunofluorescence assay was performed to test 1,044 serum samples from 747 blood donors, 73 patients presenting to casualty departments, and 224 patients attending sexually transmitted disease/AIDS clinics. The sexually transmitted disease group was composed of 88 patients with HIV (40 Kaposi sarcoma positive, 48 Kaposi sarcoma negative) and 136 patients without HIV,Results: Antibodies to human herpesvirus 8-latent nuclear antigens were found in 34 blood donors (4.6%), and in seven casualty patients (9.6%), The highest frequency of human herpesvirus 8 antibodies was found in the sexually transmitted disease group: 32 HIV-positive patients with Kaposi sarcoma (80%) and seven patients without Kaposi sarcoma (14.6%),Conclusion: The presence of human herpesvirus 8 in patients with HIV was strongly associated with Kaposi sarcoma (odds ratio, 23.4; 95% CI, 7.7-71.4), male gender, homosexual or bisexual orientation, and hepatitis B virus infection, but not with the other sexually transmitted diseases that were investigated.

Human Herpesvirus 8 (HHV-8) has been consistently associated with Primary Effusion Lymphoma (PEL or body-cavity-based lymphoma) but not with other lymphomas, This paper reports on an AIDS patient without obvious malignant effusion in body cavities but with a cutaneous lymphoma where HHV-8 and Epstein-Barr virus (EBV) were detected by PCR and electron microscopy, Both viruses were also detected in all the cells of a malignant cell line (BBG1) established from the patient's peripheral blood mononuclear cells. As in PEL and PEL-derived cell lines, both the tumor and the Lines lacked B-antigen expression in immunological studies but were of the same B origin as shown by clonal immunoglobulin gene rearrangements. In contrast to other co-infected cell lines, BBG1 and subclones spontaneously expressed the HHV-8 lytic antigens p40, p27, p60 and the EBV transforming latent antigen EBNA2. These data suggest that the clinical and biological features of HHV-8-and EBV-associated lymphomas could be wider than has been described to date in PEL particularly with the in vivo presence of circulating malignant dually-infected cells engaged in a spontaneous HHV-8 lytic infection.

Human herpesvirus 6 (HHV-6) infection is common and occurs early in life, causing exanthema subitum (roseola)1 and an acute febrile illness without rash in young children.2,3 HHV-6 infection has recently been implicated as a major cause of febrile convulsions in children4 and acute HHV-6 infections account for 10 to 20% of all febrile children seen in pediatric emergency departments.3 Serious complications have been described including disseminated infection,5 meningitis,6 encephalitis,7, 8 fulminant hepatitis9, 10 and fatal hemophagocytic syndrome.11 This report presents two cases of neonatal hepatitis associated with a primary infection with HHV-6 that could possibly have resulted from an ante- or perinatal transmission.

Ten human herpes virus 6 (HHV-6) strains from different origins were studied using reactivity to monoclonal antibodies and polymerase chain reaction analysis. Using immunofluorescence and neutralization assays, two monoclonal antibodies gave a positive reaction with the ten strains while three others only reacted with a fraction of these strains. This differential reactivity permitted segregation of the ten strains into two non-overlapping antigenic groups, designated as I and II. DNA was amplified from two regions of HHV-6 genome corresponding to the putative large tegument protein (LTP) gene and major capsid protein (MCP) gene, respectively. The restriction analysis of amplified products using HindIII for LTP and HaeII for MCP showed identical patterns among the strains belonging to the same antigenic group while BglII, TaqI and ClaI provided distinct patterns among group II strains. The nucleotide sequence of amplified products was determined and homology was found to be equal to or greater than 99% within each group whereas it was 96% between both groups. The number of amino-acid changes was higher when comparing two strains of different groups than when comparing two strains of the same group. The converging results of antigenic and genetic analyses led us to consider HHV-6 groups I and II as two distinct types of HHV-6 species.

Eight human herpesvirus 6 (HHV-6) strains were studied by Southern blot and polymerase chain reaction. DNA from infected cells was digested by a panel of restriction enzymes and hybridized with cloned BamHI fragments corresponding to about 30% of the HHV-6 strain SIE genome. In parallel, this DNA was amplified by polymerase chain reaction using pairs of primers derived from the strain SIE nucleotide sequence. Subsequently, amplification products were analyzed by hybridization, digestion with restriction endonucleases, and partial nucleotide sequencing. Overall results indicated that all strains were closely related to one another. However, concordant differences in restriction patterns allowed at least two groups to be distinguished, typified by strains SIE and HST, respectively. Differences between the two groups were found to reflect a limited number of punctual changes in nucleotide sequences. These results strengthen the idea of a unique HHV-6 species with genetic polymorphism. In addition, this study provides useful markers for the diagnosis and molecular epidemiology of HHV-6 infections.

The polymerase chain reaction (PCR) was used to detect human herpes virus 6 (HHV-6) sequences in tissue culture. A pair of primers was synthesized and used to amplify a conserved region of the genome. Amplified products were detected either by visualization of UV illuminated ethidium bromide stained gel or, by hybridization with a specific radiolabeled oligonucleotide. As little as 5 fg of HHV-6 could be detected in infected cells, making this assay suitable for diagnostic purposes.

A serological study of human herpesvirus-6 (HHV-6) infection was performed by means of immunofluorescence assay on fixed HHV-6-infected cells. Comparison between indirect immunofluorescence assay (IFA) and anticomplement immunofluorescence assay (ACIF) showed that the latter test was the most appropriate for HHV-6 serology, although both methods exhibited identical sensitivity. ACIF, which was performed on HSB2 cells infected with the HBLV strain (provided by S.Z. Salahuddin), was then used to determine the titre of HHV-6 antibodies in serum by end-point dilution. The sera from 115 healthy subjects and 99 patients with presumed viral infection were tested. A similar distribution of HHV-6 titres was evidenced in both cases and the rate of individuals exhibiting a positive titre of 20 and above was about 30% of the whole population studied. No serological cross-reactivity was observed between HHV-6 and other herpesviruses, suggesting that the HHV-6 ACIF test was quite specific.

We studied the sensitivity of human herpesvirus-6 (HHV-6) to 4 antiviral drugs known to be effective in the treatment of infections with other human herpesviruses and human immunodeficiency virus. HHV-6 was grown in peripheral blood lymphocytes, and virus multiplication was quantified by evaluation of the cytopathic effect by molecular hybridization and indirect immunofluorescence assay. The 50% and 90% inhibitory concentrations (IC50 and IC90) were determined for each drug. The results obtained by the 3 different quantification techniques were found to correlate, and enabled us to conclude that HHV-6 replication was readily inhibited by foscarnet or ganciclovir. In contrast, inhibition of HHV-6 replication was observed only at high concentrations of acyclovir, and was not detected at the tested concentrations of zidovudine.

La mise en culture de lymphocytes sanguins d'un sujet atteint de SIDA a conduit à la multiplication concomitante d'un herpesvirus humain 6 (HHV6) et d'un VIH. Cependant, la multiplication du HHV6 a progressivement occulté celle du VIH et abouti de facto à une inhibition de la réplication du VIH par le HHV6 lors des passages ultérieurs en coculture.

D uring the last 10 years, there has been growing evidence that viral infection might be an important clue to hematologic malignancies end disorders of the immune system. Adult T-cell leut emia (ATL), a distinct clinical entity initially described in Japan in 1977 [1], is the first human malignancy recognized as being associated with a retrovirus, HTLV-I (human Tcell leukemia/lymphoma virus type 1) [2]. Human immunodeficiency viruses type 1 and type 2 (HIV-1 and HIV-2) were described in 1983 and 1986, respectively, as agents responsible for the acquired immunodeficiency syndrome (AIDS) [3,4]. Recently, a novel lymphotropic herpesvirus, designated human herpesvirus 6 (HHV-6), has been suspected of playing a role in human lymphoproliferative disease [5]. Herein we describe a case of a young African woman with ATL, noteworthy for simultaneous infection with HTLV-I, HIV-2, and HHV-6, three viruses exhibiting tropism for human lymphoid cells. Since the epidemiology of the diseases thought to be linked to these viruses in Africa is still partly unknown, the results of a serologic study among the relatives of the patient will be presented.

The Epstein-Barr virus (EBV) abortive producer cell line Daudi may be induced to an incomplete cycle of viral production by chemicals such as 12-O-tetradecanoylphorbol-13-acetate (TPA) and n-butyrate. These chemicals greatly increase expression of the early antigen but not that of viral capsid antigen. DNA from these cells was cleaved with various restriction enzymes specific for the mCG sites. Viral sequences (mostly in an episomal form) were tested for their methylation patterns and compared to the methylation pattern of the producer cell line B95-8. The BamHI C, V, and H EBV DNA fragments appeared to be nonmethylated in B95-8 whether or not induced by TPA. The same fragments were partially methylated in noninduced Daudi cells. Treatment of the latter with TPA and n-butyrate increased the amount of viral DNA per cell, and hypomethylation of some EBV DNA sites occurred in parallel. Transcription changes were noted only at the level of the BamHI H fragment; cytoplasmic RNA molecules specific for this region were detected only after induction.