Absence of human herpesvirus 6B detection in association with illness in children undergoing cancer chemotherapy.

The lymphotropic herpesviruses, cytomegalovirus (CMV), Epstein-Barr virus (EBV), and human herpesvirus 6B (HHV-6B) can reactivate and cause disease in organ transplant recipients; the contributions of HHV-6A and HHV-7 to disease are less certain. Less is known about their pathogenic roles in children undergoing treatment for malignancies. Children with newly diagnosed cancer were followed for 24 months. Clinical information and blood samples were collected during routine visits and during acute visits for fever or possible viral infections. Lymphotropic herpesvirus DNA in blood was measured by polymerase chain reaction (PCR). Although HHV-6B DNA was detected at least once in about half of the patients; the other viruses were seldom detected. There was no association between HHV-6B detection and individual acute clinical events, however, HHV-6B detection was more common in children who experienced more frequent acute clinical events. In children being treated for various malignancies, HHV-6B detection was common, but was not associated with individual events of acute illness. Thus, if HHV-6B is not assessed longitudinally, clinical events may be misattributed to the virus. The elevated frequency of detection of HHV-6B in sicker children is consistent with prior reports of its detection during apparently unrelated acute clinical events. J. Med. Virol. 88:1427-1437, 2016. © 2016 Wiley Periodicals, Inc.

Roseoloviruses: unmet needs and research priorities: perspective.

The human roseoloviruses, human herpesviruses 6A (HHV-6A), HHV-6B, and HHV-7, are highly prevalent viruses that typically cause fever/rash illnesses such as roseola during early life primary infections. They also cause significant neurologic disease and complications following stem cell and solid organ transplantation, and have suggestive but less certain etiologic associations with other neurologic diseases and immunologic disorders. The US National Institute of Allergy and Infectious Diseases recently sponsored a workshop (Roseoloviruses: Clinical Impact, Interventions, and Research Needs) to discuss disease associations, novel biology, and the many unmet research needs related to Roseoloviruses. This perspective is a distillation of the workshop's presentations and discussions, with a focus on the more general research priorities that emerged.

Association between transfusion with human herpesvirus 8 antibody-positive blood and subsequent mortality.

BACKGROUND: Human herpesvirus 8 (HHV-8) is endemic in Uganda and transmissible by blood. We evaluated mortality following transfusion of HHV-8 antibody-positive blood. METHODS: In a hospital-based, observational, prospective cohort study with a 6-month follow-up, we examined the effect of HHV-8 antibody-positive blood on transfusion recipients surviving at least 7 days. RESULTS: Of 1092 recipients, 471 (43.1%) were transfused with HHV-8 antibody-positive blood. Median age was 1.8 years (range, 0.1-78); 111 (10.2%) died during follow-up. After adjusting for confounders (increasing age, human immunodeficiency virus infection, illness other than malaria, receipt of multiple transfusions), recipients of HHV-8 antibody-positive blood stored ≤4 days ("short-stored") were more likely to die than recipients of HHV-8 antibody-negative blood (adjusted hazards ratio [AHR], 1.92; 95% confidence interval [CI], 1.21-3.05; P = .01). The AHR of the effect of each additional short-stored HHV-8 antibody-positive transfusion was 1.79 (95% CI, 1.33-2.41; P = .001). CONCLUSIONS: Transfusion with short-stored HHV-8 antibody-positive blood was associated with an increased risk of death. Further research is warranted to determine if a causal pathway exists and to verify the observed association between acute HHV-8 infection and premature mortality.

Targeting cytomegalovirus-infected cells using T cells armed with anti-CD3 × anti-CMV bispecific antibody.

Human cytomegalovirus (CMV) reactivation and infection can lead to poor outcomes after allogeneic stem cell transplantation. We hypothesized that anti-CD3 activated T cells (ATCs) armed with chemically heteroconjugated anti-CD3 × polyclonal anti-CMV bispecific antibody (CMVBi) will target and eliminate CMV-infected cells. Arming doses of CMVBi as low as 0.01 ng/10(6) ATCs was able to mediate specific cytotoxicity (SC) directed at CMV-infected target cells significant above unarmed ATCs at mutiplicities of infection (MOI) between 0.01 and 1. At effector-to-target ratios (E:T) of 25:1, 12.5:1, 6.25:1, and 3.125:1, armed ATCs significantly enhanced killing of CMV-infected targets compared with unarmed ATCs. At an MOI of 1.0, the mean % SC directed at CMV-infected targets cells for CMVBi-armed ATCs at E:T of 3.12, 6.25, and 12.5 were 79%, 81%, and 82%, respectively; whereas the mean % SC for unarmed ATCs at the same E:T were all <20%. ATCs, Cytogam(®), or CMVBi alone did not lyse uninfected or CMV-infected targets. Co-cultures of CMVBi-armed ATCs with CMV-infected targets induced cytokine and chemokine release from armed ATCs. This nonmajor histocompatibility complex restricted strategy for targeting CMV could be used to prevent or treat CMV infections after allogeneic stem cell transplantation or organ transplantation.

Beta-herpesviruses in febrile children with cancer.

We conducted a cross-sectional study of beta-herpesviruses in febrile pediatric oncology patients (n = 30), with a reference group of febrile pediatric solid-organ transplant recipients (n = 9). One (3.3%) of 30 cancer patients and 3 (33%) of 9 organ recipients were PCR positive for cytomegalovirus. Four (13%) of 30 cancer patients and 3 (33%) of 9 transplant recipients had human herpesvirus 6B (HHV-6B) DNAemia, which was more common within 6 months of initiation of immune suppression (4 of 16 vs. 0 of 14 cancer patients; p = 0.050). HHV-6A and HHV-7 were not detected. No other cause was identified in children with HHV-6B or cytomegalovirus DNAemia. One HHV-6B-positive cancer patient had febrile disease with concomitant hepatitis. Other HHV-6B-positive children had mild "viral" illnesses, as did a child with primary cytomegalovirus infection. Cytomegalovirus and HHV-6B should be included in the differential diagnosis of febrile disease in children with cancer.

Human herpesvirus 8 presence and viral load are associated with the progression of AIDS-associated Kaposi's sarcoma.

OBJECTIVE: We present the largest longitudinal study to date that examines the association between Kaposi's Sarcoma (KS) disease progression and the presence and viral load of human herpesvirus 8 (HHV-8). METHODS: Ninety-six men were enrolled at HIV clinics in Atlanta, Georgia, who had KS (n = 47) or were without KS but seropositive for HHV-8. Visits occurred at 6-month intervals for 2 years at which the patient's KS status was evaluated and oral fluid and blood were collected for quantification of HHV-8 DNA and antibodies. RESULTS: The presence of HHV-8 DNA in blood was more common (P < 0.001) and the viral load higher (P < 0.001) in men with KS in comparison with men without KS. Mean HHV-8 viral loads in blood and oral fluids were associated with disease status, being highest among patients with progressing KS, intermediate among patients with stable KS, and lowest among patients with regressing KS. Consistent with our previous report high antibody titers to HHV-8 orf 65 were inversely associated with HHV-8 shedding in oral fluid. CONCLUSIONS: We observed a significant association between changes in KS disease severity and the presence and viral load of HHV-8. HHV-8 viral load in blood may provide useful information to clinicians for assessment of the risk of further disease progression in patients with KS.

Transmission of human herpesvirus 8 by blood transfusion.

BACKGROUND: Whether human herpesvirus 8 (HHV-8) is transmissible by blood transfusion remains undetermined. We evaluated the risk of HHV-8 transmission by blood transfusion in Uganda, where HHV-8 is endemic. METHODS: We enrolled patients in Kampala, Uganda, who had received blood transfusions between December 2000 and October 2001. Pretransfusion and multiple post-transfusion blood specimens from up to nine visits over a 6-month period were tested for HHV-8 antibody. We calculated the excess risk of seroconversion over time among recipients of HHV-8-seropositive blood as compared with recipients of seronegative blood. RESULTS: Of the 1811 transfusion recipients enrolled, 991 were HHV-8-seronegative before transfusion and completed the requisite follow-up, 43% of whom received HHV-8-seropositive blood and 57% of whom received seronegative blood. HHV-8 seroconversion occurred in 41 of the 991 recipients. The risk of seroconversion was significantly higher among recipients of HHV-8-seropositive blood than among recipients of seronegative blood (excess risk, 2.8%; P<0.05), and the increase in risk was seen mainly among patients in whom seroconversion occurred 3 to 10 weeks after transfusion (excess risk, 2.7%; P=0.005), a result consistent with the transmission of the virus by transfusion. Blood units stored for up to 4 days were more often associated with seroconversion than those stored for more than 4 days (excess risk, 4.2%; P<0.05). CONCLUSIONS: This study provides strong evidence that HHV-8 is transmitted by blood transfusion. The risk may be diminished as the period of blood storage increases.

Primate cytomegalovirus US12 gene family: a distinct and diverse clade of seven-transmembrane proteins.

Human cytomegalovirus (HCMV; Human herpesvirus 5) and the other betaherpesviruses encode a number of distinct gene families, including the US12 family, which is represented only in the cytomegaloviruses of higher primates, and is comprised of a set of 10 contiguous genes (US12 through US21), each encoding a seven-transmembrane (7TM) protein. Nonessential for replication in cell culture but well-conserved among clinical isolates, little is known of possible US12 family member functions, other than a previously identified amino acid sequence similarity between US21 and a group of 7TM proteins that include known inhibitors of apoptosis, and a very limited description of similarity between US12 family members and G-protein-coupled receptors (GPCR). As a prelude to biochemical analysis, we have conducted a detailed analysis of the relationships among US12 family members and between these proteins and other proteins, particularly GPCR and other 7TM molecules. In most cases, the closest relatives of individual genes are their colinear counterparts in the other viruses. Thus, the initial duplication and divergence events that resulted in the current version of the US12 family preceded divergence of the rhesus and hominoid lineages. Our phylogenetic analysis indicates that the US12 family represents a distinct branch of the 7TM superfamily. Although they are distantly related, at least some of the US12 family members may have GPCR-related properties, but they are also likely to embody functions and mechanisms that differ from more conventional GPCRs. Our analyses suggest that the 7TM structure of US12 family members constitutes a functionally flexible structural scaffold that can be readily adapted to diverse functional ends. This strategy may be the driving force in the emergence of the several families of duplicated and diverged betaherpesvirus genes.

Possible transmission of human herpesvirus-8 by blood transfusion in a historical United States cohort.

BACKGROUND: Transmission of human herpesvirus-8 (HHV-8) by blood transfusion in the United States appears plausible but has not been demonstrated. The objective of this study was to evaluate evidence of HHV-8 transmission via blood transfusion. STUDY DESIGN AND METHODS: Serum specimens were collected before and 6 months after surgery from 406 patients who enrolled in the Frequency of Agents Communicable by Transfusion study (FACTS) in Baltimore, Maryland, from 1986 to 1990. The change in HHV-8 serostatus was measured by a lytic-antigen immunofluorescence assay. RESULTS: Of the 284 patients who were initially HHV-8-seronegative and who received transfusions, 2 seroconverted, 1 with a postsurgery antibody titer of 1:160 and the other with a titer of 1:1280. These patients received 12 and 13 units of blood, respectively. None of the HHV-8-seronegative patients who did not receive transfusions seroconverted. If seroconversion was caused by transfused blood, the transmission risk per transfused component was 0.082 percent. CONCLUSIONS: This is the first report suggesting transmission of HHV-8 via blood components in the United States. Because linked donor specimens were not available, other routes of transmission cannot be excluded; however, the evidence is consistent with infection being caused by transfusion. Future studies should include contemporary US populations with linked donor specimens and populations at higher risk for HHV-8 infection.

Evidence for both lytic replication and tightly regulated human herpesvirus 8 latency in circulating mononuclear cells, with virus loads frequently below common thresholds of detection.

To address whether human herpesvirus 8 (HHV-8) DNA in peripheral blood mononuclear cells (PBMCs) might be the product of latent or lytic infection and to shed light on sporadic detection of HHV-8 DNA in individuals seropositive for the virus, we studied the frequency of infected cells, total virus load, and virus load per infected cell in PBMCs from men coinfected with HHV-8 and human immunodeficiency virus (HIV), some of whom had Kaposi's sarcoma. The low frequencies of infected cells detected (fewer than one per million cells in some individuals) suggest that the prevalence of the virus in circulating leukocytes was underestimated in previous studies that employed more conventional sampling methods (single, small-volume specimens). Mean virus loads ranged from 3 to 330 copies per infected PBMC; these numbers can represent much higher loads in individual lytically infected cells (>10(3) genomes/cell) in mixtures that consist predominantly of latently (relatively few genomes) infected cells. The presence in some subjects of high HHV-8 mean genome copy numbers per infected cell, together with viral DNA being found in plasma only from subjects with positive PBMCs, supports earlier suggestions that the virus can actively replicate in PBMCs. In some individuals, mean virus loads were less than 10 genomes per infected cell, suggesting a tightly controlled purely latent state. HHV-8 genome copy numbers are substantially higher in latently infected cells derived from primary effusion lymphomas; thus, it appears that HHV-8 is able to adopt more than one latency program, perhaps analogous to the several types of Epstein-Barr virus latency.

Repeated measures study of human herpesvirus 8 (HHV-8) DNA and antibodies in men seropositive for both HHV-8 and HIV.

OBJECTIVE: To study the natural history and pathogenesis of human herpesvirus 8 (HHV-8) infection in HHV-8-seropositive, immunosuppressed men. DESIGN: Longitudinal study of 87 HHV-8- and HIV-seropositive men [42 with Kaposi's sarcoma (KS)] during four visits over a 2 month period. METHODS: : Patients provided oral fluid and blood. HHV-8 antibody titers were measured with peptide-based enzyme-linked immunosorbent assays (ELISA) for ORF65 and K8.1; HHV-8 DNA was detected with polymerase chain reaction ELISA. RESULTS: HHV-8 DNA was present in oral fluid or peripheral blood mononuclear cells (PBMC) at one or more of the four visits in 71% of men with KS and 56% of men without KS. The strongest correlate of HHV-8 DNA in PBMC was the presence of KS [odds ratio (OR), 8.7; 95% confidence interval (CI), 3.4-22]. Detection of HHV-8 DNA in oral fluid or PBMC was often intermittent, but individuals who shed virus at one time point were more likely to shed at other times. Some men had incomplete epitope recognition in their anti-HHV-8 antibody response. High antibody titers were associated with the absence of circulating HHV-8, particularly for the ORF65 seroassay (OR, 0.16; 95% CI, 0.05-0.51). CONCLUSIONS: Among HHV-8 seropositive men, circulating virus is common even in the absence of disease. The link between KS and HHV-8 DNA in PBMC suggests that anti-herpes drugs may impede KS development or progression. Seroassays should target multiple epitopes to achieve maximal sensitivity. HHV-8 replication may be limited by high antibody titers or other immune function for which antibodies are a marker.

Elevated seroprevalence of human herpesvirus 8 among men with prostate cancer.

Background. To investigate any epidemiological association between human herpesvirus (HHV)-8 and prostate cancer, we determined the prevalence of HHV-8 seropositivity among prostate cancer case and control subjects in the United States and Trinidad and Tobago.Methods. Antibodies against HHV-8 were detected in 2 independent laboratories using either indirect immunofluorescence assay (IFA) or a combination of enzyme-linked immunosorbent assay and IFA.Results. Among 138 Tobago men with prostate cancer, HHV-8 seroprevalence was 39.9%-significantly higher than that among 140 age-matched control subjects (22.9%; P=.003; odds ratio [OR], 2.24; 95% confidence interval [CI], 1.29-3.90). Among 100 US men with prostate cancer, seroprevalence was 20%-significantly higher than that of 177 blood donors (5.1%; P=.001; OR, 4.67; 95% CI, 1.91-11.65) and higher than that of 99 men with cancer not related to HHV-8 (13%; P=.253; 95% CI, 0.77-3.54).Conclusions. HHV-8 seropositivity is elevated among men with prostate cancer compared with control subjects, which suggests that HHV-8 plays a role in the development of prostate cancer.

Human herpesvirus 8: current issues.

Although human herpesvirus 8 (HHV-8) is the etiologic agent of Kaposi sarcoma (KS), there are no formal guidelines for the clinical management of HHV-8 infection. In patients infected with human immunodeficiency virus (HIV), highly active antiretroviral therapy (HAART) is the best tool for the prevention of KS. In patients who have undergone transplantation, KS is often managed by curtailing immunosuppressive therapies, despite the potential adverse consequences for graft survival. Interventions related to HHV-8 infection might improve the management of KS in immunocompromised patients. However, knowledge from HHV-8 research cannot yet be translated into clinically useful interventions. Achieving clinical utility will require the commercial development of diagnostic tools currently available only in research settings and the evaluation of potential interventions. Such interventions might include the use of HHV-8 diagnostics to identify patients at high risk and to aid in the early detection of KS, prophylaxis with antiherpes drugs to prevent KS, treatment of KS with antiherpes drugs, and donor/recipient screening for organ transplantation.

Kaposi's sarcoma in Uganda: risk factors for human herpesvirus 8 infection among blood donors.

Human herpesvirus 8 (HHV-8) is etiologically linked to Kaposi's sarcoma, a common cancer in Uganda. The authors assessed HHV-8 seroprevalence, risk factors for infection, and HHV-8 assays in a cross-sectional study of Ugandan blood donors. Of 3,736 specimens, the authors selected 203 reactive for HIV, hepatitis B surface antigen (HBsAg), or syphilis, and, randomly, 203 nonreactive specimens. For HHV-8 testing, the authors used two peptide-based enzyme-linked immunosorbent assays (EIAs), ORFK8.1 and ORF65, and an immunofluorescence assay (IFA). Specimens reactive in at least two assays or on IFA alone were considered HHV-8-seropositive. Prevalence estimates were weighted to account for the sampling scheme. Overall HHV-8 seroprevalence was 40%. HHV-8 seroprevalence was higher among HBsAg-positive donors (53%) than HBsAg-negative donors (39%; p =.02) and higher among HIV-positive donors (63%) than HIV-negative donors (39%; p <.001). HHV-8 seroreactivity showed no trend with age. Kappa values for assay concordances were 0.68 (ORFK8.1 EIA and IFA), 0.37 (ORF65 EIA and K8.1 EIA), and 0.29 (ORF65 EIA and IFA). The association between HHV-8 and HBsAg positivity and the lack of association between HHV-8 and age point to primarily nonsexual HHV-8 transmission during childhood. The association with HIV indicates sexual transmission may also occur. The role of ORF65 EIA in testing specimens from Africa warrants further evaluation.

Prevalence of and risk factors for viral infections among human immunodeficiency virus (HIV)-infected and high-risk HIV-uninfected women.

Viruses that can persist in the host are of special concern in immunocompromised populations. Among 871 human immunodeficiency virus (HIV)-infected and 439 high-risk HIV-uninfected women, seroprevalences of cytomegalovirus, hepatitis B virus, hepatitis C virus, and herpes simplex virus types 1 and 2 and prevalence of human papillomavirus DNA in cervicovaginal lavage fluids were all >50% and were 2-30 times higher than prevalences in the general population. Prevalences were highest among HIV-infected women, of whom 44.2% had >or=5 other infections, and were relatively high even among the youngest women (age 16-25 years). In multivariate analyses, viral infections were independently associated not only with behaviors such as injection drug use and commercial sex but also with low income, low levels of education, and black race. Disadvantaged women and women who engage in high-risk behaviors are more likely to be coinfected with HIV and other viruses and, thus, may be at high risk of serious disease sequelae.

Risk factors for Kaposi's sarcoma in men seropositive for both human herpesvirus 8 and human immunodeficiency virus.

OBJECTIVE: To identify risk factors for Kaposi's sarcoma (KS) among men seropositive for both human herpesvirus 8 (HHV-8) and HIV. DESIGN: Cross-sectional study of 91 HHV-8 seropositive, HIV seropositive men who have sex with men (57 with KS), and 70 controls at lower risk for KS. METHODS: Patients received clinical evaluations. Blood, oral fluids, semen, rectal brush, rectal swab, and urine were collected, and tests for HHV-8 were performed. RESULTS: Men with KS were more likely to have HHV-8 DNA in peripheral blood mononuclear cells (PBMC) than men without KS [35.1 versus 5.9%, odds ratio (OR), 8.6, 95% confidence interval (CI), 1.9-39.9]. The prevalence of HHV-8 DNA in oral fluids was similar for the two groups (37.0 versus 32.4%; OR, 1.2; 95% CI, 0.5-3.0). HHV-8 DNA was rarely detected in specimens of other types from these men, or in any specimens from the 70 controls. Among men with KS, HHV-8 DNA in PBMC was associated with new KS lesions (OR, 4.5; 95% CI, 1.4-14.5), and HHV-8 DNA in oral fluids was associated with oropharyngeal KS lesions (OR, 3.1; 95% CI, 1.0-10.1). Men with high HHV-8 antibody titers were more likely to have KS (OR, 9.6; 95% CI, 1.2-78.2), but were less likely to have new KS lesions (OR, 0.2; 95% CI, 0.0-1.1) or HHV-8 DNA in PBMC (OR, 0.2; 95% CI, 0.0-1.6) or oral fluids (OR, undefined; = 0.001). CONCLUSIONS: In HHV-8- and HIV-seropositive men, HHV-8 DNA is associated with KS. Among men without KS, HHV-8 DNA is most commonly found in oral fluids. High HHV-8 antibody titers may protect against circulating HHV-8 and new KS lesions.

Highly sensitive assay for human herpesvirus 8 antibodies that uses a multiple antigenic peptide derived from open reading frame K8.1.

The immunodominant region of the human herpesvirus 8 (HHV-8), the antibody-binding site of glycoprotein K8.1A, was mapped to the N-terminal region by using overlapping peptides and a residue replacement method. The main epitope was located within residues 44 to 56 (GQVYQDWL----C). Based on this information, we developed an enzyme immunoassay to detect HHV-8 antibodies in human sera using a four-branch multiple antigenic peptide as the antigen. The sensitivity and specificity of the assay were 96 and 99.4%, respectively. This assay should be useful for population-based, epidemiological studies of HHV-8 infection.

Molecular characterization of strains of Human herpesvirus 8 from Japan, Argentina and Kuwait.

Current genotyping systems for Human herpesvirus 8 (HHV-8) are based on the highly variable gene encoding the K1 glycoprotein. Most strains collected worldwide cluster into two subtypes (I/A and II/C). Sequenced African strains have belonged to subtypes I/A and IV/B. Members of all three of these subtypes can have either the M or P allele at the right-hand side (RHS) of the genome. Strains obtained predominantly from aboriginal or relatively isolated populations have formed clades that branch at a distance from subtypes I/A and II/C, all being of the RHS P allele. The characterization is reported here of 16 Japanese, two Kuwaiti and five Argentine HHV-8 strains obtained from human immunodeficiency virus-infected and non-infected patients with Kaposi's sarcoma (KS), primary effusion lymphoma, multicentric Castleman's disease or renal transplants. K1 sequences of five Japanese, one Kuwaiti and two Argentine strains were identified as subtype I/A and eight Japanese, one Kuwaiti and three Argentine strains were subtype II/C. Three strains from elderly classic KS patients originally from Hokkaido, a northern Japanese island, were relatively closely related to strains of subtypes III/D and E. Consistent with previous observations, both the M and P alleles were identified at the RHS of subgroup I/A and II/C genomes; only the P allele was detected among the three Hokkaido strains. Distances among the Hokkaido strains were similar to the distance between subtypes I/A and II/C, suggesting that the Hokkaido strains may represent two distinct subtypes and that, as more strains are analysed, the currently recognized III/D subgroups will probably emerge as independent subtypes.