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New Insights from the High-Resolution Monitoring of Microalgae–Virus Infection Dynamics. Viruses 2022; 14:v14030466. [PMID: 35336873 PMCID: PMC8954724 DOI: 10.3390/v14030466] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 02/21/2022] [Accepted: 02/22/2022] [Indexed: 12/10/2022] Open
Abstract
Investigation of virus-induced microalgal host lysis and the associated infection dynamics typically requires sampling of infected cultures at multiple timepoints, visually monitoring the state of infected cells, or determining virus titration within the culture media. Such approaches require intensive effort and are prone to low sensitivity and high error rates. Furthermore, natural physiological variations can become magnified by poor environmental control, which is often compounded by variability in virus stock efficacy and relatively long infection cycles. We introduce a new method that closely monitors host health and integrity to learn about the infection strategy of Chloroviruses. Our approach combines aspects of spectrometry, plaque assays, and infection dose assessment to monitor algal cells under conditions more representative of the natural environment. Our automated method exploits the continuous monitoring of infected microalgae cultures in highly controlled lab-scale photobioreactors that provide the opportunity for environmental control, technical replication, and intensive culture monitoring without external intervention or culture disruption. This approach has enabled the development of a protocol to investigate molecular signalling impacting the virus life cycle and particle release, accurate determination of virus lysis time under multiple environmental conditions, and assessment of the functional diversity of multiple virus isolates.
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Genome-Wide Approach to the CD4 T-Cell Response to Human Herpesvirus 6B. J Virol 2019; 93:JVI.00321-19. [PMID: 31043533 DOI: 10.1128/jvi.00321-19] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Accepted: 04/29/2019] [Indexed: 02/07/2023] Open
Abstract
Human herpesvirus 6 (HHV-6) and cytomegalovirus (CMV) are population-prevalent betaherpesviruses with intermittent lytic replication that can be pathogenic in immunocompromised hosts. Elucidation of the adaptive immune response is valuable for understanding pathogenesis and designing novel treatments. Knowledge of T-cell antigens has reached the genome-wide level for CMV and other human herpesviruses, but study of HHV-6 is at an earlier stage. Using rare-cell enrichment combined with an HLA-agnostic, proteome-wide approach, we queried HHV-6B-specific CD4 T cells from 18 healthy donors with each known HHV-6B protein. We detected a low abundance of HHV-6-specific CD4 T cells in blood; however, the within-person CD4 T-cell response is quite broad: the median number of open reading frame (ORF) products recognized was nine per person. Overall, the data expand the number of documented HHV-6B CD4 T-cell antigens from approximately 11 to 60. Epitopes in the proteins encoded by U14, U90, and U95 were mapped with synthetic peptides, and HLA restriction was defined for some responses. Intriguingly, CD4 T-cell antigens newly described in this report are among the most population prevalent, including U73, U72, U95, and U30. Our results indicate that selection of HHV-6B ORFs for immunotherapy should consider this expanded panel of HHV-6B antigens.IMPORTANCE Human herpesvirus 6 is highly prevalent and maintains chronic infection in immunocompetent individuals, with the potential to replicate widely in settings of immunosuppression, leading to clinical disease. Antiviral compounds may be ineffective and/or pose dose-limiting toxicity, and therefore, immune-based therapies have garnered increased interest in recent years. Attempts at addressing this unmet medical need begin with understanding the cellular response to HHV-6 at the individual and population levels. The present study provides a comprehensive assessment of HHV-6-specific T-cell responses that may inform the development of cell-based therapies directed at this virus.
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3
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Hanson DJ, Hill JA, Koelle DM. Advances in the Characterization of the T-Cell Response to Human Herpesvirus-6. Front Immunol 2018; 9:1454. [PMID: 29988505 PMCID: PMC6026635 DOI: 10.3389/fimmu.2018.01454] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Accepted: 06/12/2018] [Indexed: 12/29/2022] Open
Abstract
Human herpesvirus (HHV) 6 is thought to remain clinically latent in most individuals after primary infection and to reactivate to cause disease in persons with severe immunosuppression. In allogeneic hematopoietic stem cell transplant recipients, reactivation of HHV-6 species B is a considerable cause of morbidity and mortality. HHV-6B reactivation is the most frequent cause of infectious meningoencephalitis in this setting and has been associated with a variety of other complications such as graft rejection and acute graft versus host disease. This has inspired efforts to develop HHV-6-targeted immunotherapies. Basic knowledge of HHV-6-specific adaptive immunity is crucial for these endeavors, but remains incomplete. Many studies have focused on specific HHV-6 antigens extrapolated from research on human cytomegalovirus, a genetically related betaherpesvirus. Challenges to the study of HHV-6-specific T-cell immunity include the very low frequency of HHV-6-specific memory T cells in chronically infected humans, the large genome size of HHV-6, and the lack of an animal model. This review will focus on emerging techniques and methodological improvements that are beginning to overcome these barriers. Population-prevalent antigens are now becoming clear for the CD4+ T-cell response, while definition and ranking of CD8+ T-cell antigens and epitopes is at an earlier stage. This review will discuss current knowledge of the T-cell response to HHV-6, new research approaches, and translation to clinical practice.
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Affiliation(s)
- Derek J Hanson
- Department of Medicine, University of Washington, Seattle, WA, United States.,Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, WA, United States
| | - Joshua A Hill
- Department of Medicine, University of Washington, Seattle, WA, United States.,Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, WA, United States
| | - David M Koelle
- Department of Medicine, University of Washington, Seattle, WA, United States.,Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, WA, United States.,Department of Laboratory Medicine, University of Washington, Seattle, WA, United States.,Department of Global Health, University of Washington, Seattle, WA, United States.,Benaroya Research Institute, Seattle, WA, United States
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4
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Foukas PG, Tsiodras S, Economopoulou P, Spathis A, Mademli M, Leventakos K, Psyrri A, Karakitsos P, Panayiotides IG. Concomitant Human Herpes Virus 6 and nivolumab-related pneumonitis: Potential pathogenetic insights. IDCases 2018; 11:101-103. [PMID: 29552493 PMCID: PMC5852387 DOI: 10.1016/j.idcr.2018.01.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2018] [Revised: 01/29/2018] [Accepted: 01/29/2018] [Indexed: 12/12/2022] Open
Abstract
The development of immune system modulating agents, such as immune checkpoint inhibitors (ICIs), has revolutionized cancer treatment. Nivolumab, a human monoclonal antibody against PD-1, has emerged as an efficient treatment for various malignancies, including non-small cell lung cancer (NSCLC); however, it is associated with important immune related side-effects, attributed to organ-specific inflammation, such as immune-mediated pneumonitis, a relatively uncommon, albeit potentially fatal adverse event. We herein present the unique case of severe interstitial pneumonitis with concomitant detection of Human Herpes Virus 6 (HHV-6) in a nivolumab treated patient with NSCLC. Potential pathogenetic mechanisms are discussed.
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Affiliation(s)
- Periklis G Foukas
- 2nd Department of Pathology, School of Medicine, National and Kapodistrian University of Athens, Attikon University Hospital, Athens, Greece
| | - Sotirios Tsiodras
- 4th Department of Internal Medicine, School of Medicine, National and Kapodistrian University of Athens, Attikon University Hospital, Athens, Greece
| | - Panagiota Economopoulou
- Medical Oncology Unit, 2nd Department of Internal Medicine, School of Medicine, National and Kapodistrian University of Athens, Attikon University Hospital, Athens, Greece
| | - Aris Spathis
- Department of Cytopathology, School of Medicine, National and Kapodistrian University of Athens, Attikon University Hospital, Athens, Greece
| | - Maria Mademli
- 2nd Department of Radiology, School of Medicine, National and Kapodistrian University of Athens, Attikon University Hospital, Athens, Greece
| | - Konstantinos Leventakos
- 2nd Department of Pathology, School of Medicine, National and Kapodistrian University of Athens, Attikon University Hospital, Athens, Greece
| | - Amanda Psyrri
- Medical Oncology Unit, 2nd Department of Internal Medicine, School of Medicine, National and Kapodistrian University of Athens, Attikon University Hospital, Athens, Greece
| | - Petros Karakitsos
- Department of Cytopathology, School of Medicine, National and Kapodistrian University of Athens, Attikon University Hospital, Athens, Greece
| | - Ioannis G Panayiotides
- 2nd Department of Pathology, School of Medicine, National and Kapodistrian University of Athens, Attikon University Hospital, Athens, Greece
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5
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Aburjania N, Abu Saleh OM, Razonable RR. How do we treat human herpesvirus 6 infection after allogeneic hematopoietic stem cell transplantation? Future Virol 2017. [DOI: 10.2217/fvl-2016-0140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Affiliation(s)
- Nana Aburjania
- Division of Infectious Diseases, Department of Medicine, The William J von Liebig Center for Transplantation & Clinical Regeneration, Mayo Clinic, Rochester, MN 55905, USA
| | - Omar M Abu Saleh
- Division of Infectious Diseases, Department of Medicine, The William J von Liebig Center for Transplantation & Clinical Regeneration, Mayo Clinic, Rochester, MN 55905, USA
| | - Raymund R Razonable
- Division of Infectious Diseases, Department of Medicine, The William J von Liebig Center for Transplantation & Clinical Regeneration, Mayo Clinic, Rochester, MN 55905, USA
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6
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Prusty BK, Siegl C, Hauck P, Hain J, Korhonen SJ, Hiltunen-Back E, Puolakkainen M, Rudel T. Chlamydia trachomatis infection induces replication of latent HHV-6. PLoS One 2013; 8:e61400. [PMID: 23620749 PMCID: PMC3631192 DOI: 10.1371/journal.pone.0061400] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2013] [Accepted: 03/08/2013] [Indexed: 11/19/2022] Open
Abstract
Human herpesvirus-6 (HHV-6) exists in latent form either as a nuclear episome or integrated into human chromosomes in more than 90% of healthy individuals without causing clinical symptoms. Immunosuppression and stress conditions can reactivate HHV-6 replication, associated with clinical complications and even death. We have previously shown that co-infection of Chlamydia trachomatis and HHV-6 promotes chlamydial persistence and increases viral uptake in an in vitro cell culture model. Here we investigated C. trachomatis-induced HHV-6 activation in cell lines and fresh blood samples from patients having Chromosomally integrated HHV-6 (CiHHV-6). We observed activation of latent HHV-6 DNA replication in CiHHV-6 cell lines and fresh blood cells without formation of viral particles. Interestingly, we detected HHV-6 DNA in blood as well as cervical swabs from C. trachomatis-infected women. Low virus titers correlated with high C. trachomatis load and vice versa, demonstrating a potentially significant interaction of these pathogens in blood cells and in the cervix of infected patients. Our data suggest a thus far underestimated interference of HHV-6 and C. trachomatis with a likely impact on the disease outcome as consequence of co-infection.
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Affiliation(s)
- Bhupesh K. Prusty
- Biocenter, Chair of Microbiology, University of Würzburg, Würzburg, Germany
| | - Christine Siegl
- Biocenter, Chair of Microbiology, University of Würzburg, Würzburg, Germany
| | - Petra Hauck
- Biocenter, Chair of Microbiology, University of Würzburg, Würzburg, Germany
| | - Johannes Hain
- Institute of Mathematics, Chair of Mathematics VIII (Statistics), University of Würzburg, Würzburg, Germany
| | - Suvi J. Korhonen
- Haartman Institute, Department of Virology, University of Helsinki, Helsinki, Finland
| | - Eija Hiltunen-Back
- Clinic of Venereal Diseases, Skin and Allergy Hospital, Helsinki University Central Hospital, Helsinki, Finland
- Department of Infectious Disease Surveillance and Control, National Institute of Health and Welfare, Helsinki, Finland
| | - Mirja Puolakkainen
- Haartman Institute, Department of Virology, University of Helsinki, Helsinki, Finland
- Helsinki University Central Hospital, Laboratory Division (HUSLAB), Department of Virology and Immunology, Helsinki, Finland
| | - Thomas Rudel
- Biocenter, Chair of Microbiology, University of Würzburg, Würzburg, Germany
- * E-mail:
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7
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Matthes-Martin S, Feuchtinger T, Shaw P, Engelhard D, Hirsch H, Cordonnier C, Ljungman P. European guidelines for diagnosis and treatment of adenovirus infection in leukemia and stem cell transplantation: summary of ECIL-4 (2011). Transpl Infect Dis 2012; 14:555-63. [DOI: 10.1111/tid.12022] [Citation(s) in RCA: 194] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2012] [Revised: 08/15/2012] [Accepted: 08/15/2012] [Indexed: 11/27/2022]
Affiliation(s)
- S. Matthes-Martin
- Department of Pediatrics; Stem Cell Transplantation Unit; St Anna Children's Hospital; Medical University; Vienna; Austria
| | - T. Feuchtinger
- Department of Pediatrics; University Hospital; Tübingen; Germany
| | - P.J. Shaw
- Oncology Unit; The Children's Hospital at Westmead; Sydney; Australia
| | - D. Engelhard
- Department of Pediatrics; Hadassah University Hospital; Jerusalem; Israel
| | - H.H. Hirsch
- Department of Virology; University Hospital; Basel; Switzerland
| | - C. Cordonnier
- Department of Hematology; Hôpital Henri Mondor; Assistance Publique-Hôpitaux de Paris, and Université Paris-Est Créteil; Creteil; France
| | - P. Ljungman
- Department of Hematology; Karolinska University Hospital, and Department of Medicine Huddinge; Section of Hematology; Karolinska Institutet; Stockholm; Sweden
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Quantitation of human herpesvirus-6A, -6B and -7 DNAs in whole blood, mononuclear and polymorphonuclear cell fractions from healthy blood donors. J Clin Virol 2012; 53:151-5. [DOI: 10.1016/j.jcv.2011.10.017] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2011] [Revised: 10/17/2011] [Accepted: 10/26/2011] [Indexed: 01/22/2023]
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10
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Razonable RR, Lautenschlager I. Impact of human herpes virus 6 in liver transplantation. World J Hepatol 2010; 2:345-53. [PMID: 21161019 PMCID: PMC2998978 DOI: 10.4254/wjh.v2.i9.345] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/10/2010] [Revised: 07/14/2010] [Accepted: 07/21/2010] [Indexed: 02/06/2023] Open
Abstract
Human herpes virus 6 (HHV-6) infects > 95% of humans. Primary infection which occurs mostly during the first 2 years of life in the form of roseola infantum, non-specific febrile illness, or an asymptomatic illness, results in latency. Reactivation of latent HHV-6 is common after liver transplantation. Since the majority of human beings harbor the latent virus, HHV-6 infections after liver transplantation are most probably caused by endogenous reactivation or superinfection. In a minority of cases, primary HHV-6 infection may occur when an HHV-6-seronegative individual receives a liver allograft from an HHV-6-seropositive donor. The vast majority of HHV-6 infections after liver transplantation are asymptomatic. Only in a minority of cases, when HHV-6 causes a febrile illness associated with rash and myelosuppression, hepatitis, gastroenteritis, pneumonitis, and encephalitis after liver transplantation. In addition, HHV-6 has been implicated in a variety of indirect effects, such as allograft rejection and increased predisposition to and severity of other infections, including cytomegalovirus, hepatitis C virus, and opportunistic fungi. Because of the uncommon nature of the clinical illnesses directly attributed to HHV-6, there is currently no recommended HHV-6-specific approach prevention after liver transplantation. Asymptomatic HHV-6 infection does not require antiviral treatment, while treatment of established HHV-6 disease is treated with intravenous ganciclovir, foscarnet, or cidofovir and this should be complemented by a reduction in immunosuppression.
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Affiliation(s)
- Raymund R Razonable
- Raymund R Razonable, Division of Infectious Diseases, Department of Medicine, and the William J von Liebig Transplant Center, College of Medicine, Mayo Clinic, Rochester, MN 55905, United States
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11
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Hall CB, Caserta MT, Schnabel KC, Shelley LM, Carnahan JA, Marino AS, Yoo C, Lofthus GK. Transplacental congenital human herpesvirus 6 infection caused by maternal chromosomally integrated virus. J Infect Dis 2010; 201:505-7. [PMID: 20088693 DOI: 10.1086/650495] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Congenital human herpesvirus 6 (HHV-6) infection results from germline passage of chromosomally integrated HHV-6 (CI-HHV-6) and from transplacental passage of maternal HHV-6 infection. We aimed to determine whether CI-HHV-6 could replicate and cause transplacentally acquired HHV-6 infection. HHV-6 DNA, variant type, and viral loads were determined with samples (cord blood, peripheral blood, saliva, urine, and hair) obtained from 6 infants with transplacentally acquired HHV-6 and with samples of their parents' hair. No fathers but all mothers of infants with transplacentally acquired HHV-6 had CI-HHV-6, and the mother's CI-HHV-6 variant was the same variant causing the transplacentally acquired congenital HHV-6 infection. This suggests the possibility that CI-HHV-6 replicates and may cause most, if not all, congenital HHV-6 infections.
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Affiliation(s)
- Caroline Breese Hall
- Department of Pediatrics, University of Rochester School of Medicine and Dentistry, Rochester, New York 14642, USA.
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Li YT, Emery VC, Surah S, Jarmulowicz M, Sweny P, Kidd IM, Griffiths PD, Clark DA. Extensive human cytomegalovirus (HCMV) genomic DNA in the renal tubular epithelium early after renal transplantation: Relationship with HCMV DNAemia and long-term graft function. J Med Virol 2010; 82:85-93. [DOI: 10.1002/jmv.21662] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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13
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Abstract
Human herpesvirus 6 (HHV-6) infections occur in > 95% of humans. Primary infection, which occurs in early childhood as an asymptomatic illness or manifested clinically as roseola infantum, leads to a state of subclinical viral persistence and latency. Reactivation of latent HHV-6 is common after liver transplantation, possibly induced and facilitated by allograft rejection and immunosuppressive therapy. Since the vast majority of humans harbor the virus in a latent state, HHV-6 infections after liver transplantation are believed to be mostly due to endogenous reactivation or superinfection (reactivation in the transplanted organ). In a minority of cases, however, primary HHV-6 infection may occur when an HHV-6 negative individual receives a liver allograft from an HHV-6 positive donor. The vast majority of documented HHV-6 infections after liver transplantation are asymptomatic. In a minority of cases, HHV-6 has been implicated as a cause of febrile illness with rash and myelosuppression, hepatitis, pneumonitis, and encephalitis after liver transplantation. In addition, HHV-6 has been associated with a variety of indirect effects such as allograft rejection, and increased predisposition and severity of other infections including cytomegalovirus (CMV), hepatitis C virus, and opportunistic fungi. Because of the uncommon nature of the clinical illnesses directly attributed to HHV-6, there is currently no recommended HHV-6-specific approach to prevention. However, ganciclovir and valganciclovir, which are primarily intended for the prevention of CMV disease, are also active against HHV-6 and may prevent its reactivation after transplantation. The treatment of established HHV-6 disease is usually with intravenous ganciclovir, cidofovir, or foscarnet, complemented by reduction in the degree of immunosuppression. This article reviews the current advances in the pathogenesis, clinical diagnosis, and therapeutic modalities against HHV6 in the setting of liver transplantation.
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Bates M, Monze M, Bima H, Kapambwe M, Clark D, Kasolo FC, Gompels UA. Predominant human herpesvirus 6 variant A infant infections in an HIV-1 endemic region of Sub-Saharan Africa. J Med Virol 2009; 81:779-89. [PMID: 19319952 DOI: 10.1002/jmv.21455] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Human herpesvirus 6, HHV-6, commonly infects children, causing febrile illness and can cause more severe pathology, especially in an immune compromised setting. There are virulence distinctions between variants HHV-6A and B, with evidence for increased severity and neurotropism for HHV-6A. While HHV-6B is the predominant infant infection in USA, Europe and Japan, HHV-6A appears rare. Here HHV-6 prevalence, loads and variant genotypes, in asymptomatic compared to symptomatic infants were investigated from an African region with endemic HIV-1/AIDS. DNA was extracted from blood or sera from asymptomatic infants at 6 and 18 months age in a population-based micronutrient study, and from symptomatic infants hospitalised for febrile disease. DNA was screened by qualitative and quantitative real-time PCR, then genotyped by sequencing at variable loci, U46 (gN) and U47 (gO). HIV-1 serostatus of infants and mothers were also determined. HHV-6 DNA prevalence rose from 15% to 22% (80/371) by 18 months. At 6 months, infants born to HIV-1 positive mothers had lower HHV-6 prevalence (11%, 6/53), but higher HCMV prevalence (25%, 17/67). HHV-6 positive febrile hospitalized infants had higher HIV-1, 57% (4/7), compared to asymptomatic infants, 3% (2/74). HHV-6A was detected exclusively in 86% (48/56) of asymptomatic HHV-6 positive samples genotyped. Co-infections with both strain variants were linked with higher viral loads and found in 13% (7/56) asymptomatic infants and 43% (3/7) HIV-1 positive febrile infants. Overall, the results show HHV-6A as the predominant variant significantly associated with viremic infant-infections in this African population, distinct from other global cohorts, suggesting emergent infections elsewhere.
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Affiliation(s)
- Matthew Bates
- Pathogen Molecular Biology Unit, Department of Infectious & Tropical Diseases, London School of Hygiene & Tropical Medicine, University of London, London, United Kingdom
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15
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Ward KN. Unique route for human herpesvirus transmission: HHV-6 and chromosomal integration. Future Virol 2009. [DOI: 10.2217/fvl.09.3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Evaluation of: Hall CB, Caserta MT, Schnabel K et al.: Chromosomal integration of human herpesvirus 6 is the major mode of congenital human herpesvirus 6 infection. Pediatrics 122(3), 513–520 (2005). Human herpesvirus (HHV) -6 is the cause of exanthem subitum, a common childhood illness. In common with the other human HHVs, it establishes lifelong latency with occasional reactivation, but unlike the other members of its family, it has an alternative form of persistence, specifically, integration of viral sequences into host chromosomes characterized by very high HHV-6 DNA loads in blood. This phenomenon was first discovered in the early 1990s but, until recently, was considered extremely rare. However, accumulating evidence suggests that chromosomal integration is uncommon rather than rare and that its usual mode of transmission is in the germline. The present article confirms this possibility; it is the culmination of an ongoing prospective survey of congenital HHV-6 infection that will no doubt shed further light on the, as of yet, unknown clinical consequences of the fascinating phenomenon of chromosomally integrated HHV-6.
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Affiliation(s)
- Katherine N Ward
- Centre for Virology, Division of Infection & Immunity, University College Medical School, Windeyer Institute of Medical Sciences, 46 Cleveland Street, London, W1T 4JF, UK
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Hall CB, Caserta MT, Schnabel K, Shelley LM, Marino AS, Carnahan JA, Yoo C, Lofthus GK, McDermott MP. Chromosomal integration of human herpesvirus 6 is the major mode of congenital human herpesvirus 6 infection. Pediatrics 2008; 122:513-20. [PMID: 18762520 DOI: 10.1542/peds.2007-2838] [Citation(s) in RCA: 157] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
OBJECTIVE We examined the frequency and characteristics of chromosomally integrated human herpesvirus 6 among congenitally infected children. METHODS Infants with and without congenital human herpesvirus 6 infection were prospectively monitored. Cord blood mononuclear cell, peripheral blood mononuclear cell, saliva, urine, and hair follicle samples were examined for human herpesvirus 6 DNA. Human herpesvirus 6 RNA, serum antibody, and chromosomally integrated human herpesvirus 6 levels were also assessed. RESULTS Among 85 infants, 43 had congenital infections and 42 had postnatal infections. Most congenital infections (86%) resulted from chromosomally integrated human herpesvirus 6; 6 infants (14%) had transplacental infections. Children with chromosomally integrated human herpesvirus 6 had high viral loads in all sites (mean: 5-6 log(10) genomic copies per mug of cellular DNA); among children with transplacental infection or postnatal infection, human herpesvirus 6 DNA was absent in hair samples and inconsistent in other samples, and viral loads were significantly lower. One parent of each child with chromosomally integrated human herpesvirus 6 who had parental hair samples tested had hair containing human herpesvirus 6 DNA. Variant A caused 32% of chromosomally integrated human herpesvirus 6 infections, compared with 2% of postnatal infections. Replicating human herpesvirus 6 was detected only among chromosomally integrated human herpesvirus 6 samples (8% of cord blood mononuclear cells and peripheral blood mononuclear cells). Cord blood human herpesvirus 6 antibody levels were similar among children with chromosomally integrated human herpesvirus 6, transplacental infection, and postnatal infection and between children with maternal and paternal chromosomally integrated human herpesvirus 6 transmission. CONCLUSIONS Human herpesvirus 6 congenital infection results primarily from chromosomally integrated virus which is passed through the germ-line. Infants with chromosomally integrated human herpesvirus 6 had high viral loads in all specimens, produced human herpesvirus 6 antibody, and mRNA. The clinical relevance needs study as 1 of 116 newborns may have chromosomally integrated human herpesvirus 6 blood specimens.
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Affiliation(s)
- Caroline Breese Hall
- Department of Pediatrics, University of Rochester School of Medicine and Dentistry, 601 Elmwood Ave, Box 689, Rochester, NY 14642, USA.
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Ljungman P, Wang FZ, Clark DA, Emery VC, Remberger M, Ringdén O, Linde A. High levels of human herpesvirus 6 DNA in peripheral blood leucocytes are correlated to platelet engraftment and disease in allogeneic stem cell transplant patients. Br J Haematol 2008. [DOI: 10.1111/j.1365-2141.2000.02422.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Hudnall SD, Chen T, Allison P, Tyring SK, Heath A. Herpesvirus prevalence and viral load in healthy blood donors by quantitative real-time polymerase chain reaction. Transfusion 2008; 48:1180-7. [PMID: 18422852 DOI: 10.1111/j.1537-2995.2008.01685.x] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND After primary infection, human herpesviruses (HHVs) maintain long-term latent persistence, often punctuated years later by sporadic episodes of symptomatic lytic activation. Also, blood-borne herpesvirus from healthy persistently infected blood donors can lead to active primary infection of immunocompromised transfusion recipients. STUDY DESIGN AND METHODS Utilizing a set of newly developed real-time polymerase chain reaction assays for detection and quantification of all eight human herpesviruses, the prevalence and viral DNA load of white cell-enriched blood from 100 randomly selected blood donors from the southeast Texas region are reported. RESULTS Herpes simplex viruses 1 and 2 (HSV-1 and HSV-2), varicella-zoster virus (VZV), and HHV-8 DNA were not detected in any donor sample. In contrast, Epstein-Barr virus (EBV) (72%) and HHV-7 (65%) were commonly detected, HHV-6 (30%) was often detected (Type B only), and cytomegalovirus (CMV; 1%) was rarely detected. Median viral loads of positive samples (per milliliter of blood) ranged from 4278 for HHV-6 to less than 46 for EBV. CONCLUSIONS These results suggest that the potential for transfusion-mediated transmission of herpesviruses from healthy adult blood donors is high for EBV and HHV-7; moderately high for HHV-6; uncommon for CMV; and rare for HSV-1, HSV-2, VZV, and HHV-8. Perhaps the most remarkable finding in this study was the detection of a single donor sample with greater than 6.1 x 10(7) HHV-6 Type B genome equivalents per mL blood. Given that this extraordinarily high level of HHV-6 DNA was obtained from a healthy adult blood donor, this phenomenon is likely unrelated to active infection or immunodeficiency.
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Affiliation(s)
- S David Hudnall
- Department of Pathology and Laboratory Medicine, University of Texas Medical Branch, Galveston, TX 77555-0741, USA.
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Detection and typing of human herpesvirus 6 by molecular methods in specimens from patients diagnosed with encephalitis or meningitis. J Clin Microbiol 2007; 45:3972-8. [PMID: 17942643 DOI: 10.1128/jcm.01692-07] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Human herpesvirus 6 (HHV-6) was detected in specimens from patients hospitalized with symptoms of encephalitis or meningitis. A real-time PCR assay was developed which has a linear dynamic range of 5 to 5 x 10(6) copies of HHV-6 and a sensitivity of five gene copies per reaction. While the assay detects both subtypes, HHV-6A and HHV-6B, it is specific and does not cross-react with a selected specificity panel. A total of 1,482 patient specimens, which were collected between 2003 and 2007, were tested; 26 specimens from 24 patients were found to be positive for HHV-6 by real-time PCR. The HHV-6 detection rate in this population was therefore 1.75%. The majority of the specimens tested (>95%) were cerebrospinal fluid (CSF) specimens. We were able to type 20 of the 26 positive specimens by conventional PCR and sequence analysis; all were HHV-6B. Forty-two percent of the patients were 3 years of age or younger, which may indicate a primary infection in these patients. Given the ages of the remaining patients (from 4 to 81 years), their infections were most probably due to virus reactivations. Where information was available, symptoms of patients included fever (71%), altered mental status (67%), and abnormal CSF profile (75%). Fifty percent of patients of 3 years of age or younger suffered from seizures. The detection of HHV-6 in specimens from patients diagnosed with encephalitis or meningitis, in the absence of a positive PCR result for other agents, strongly suggests a role for HHV-6 in the pathogenesis of these central nervous system diseases.
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Maslin J, Bigaillon C, Froussard F, Enouf V, Nicand E. Acute bilateral uveitis associated with an active human herpesvirus-6 infection. J Infect 2007; 54:e237-40. [PMID: 17303245 DOI: 10.1016/j.jinf.2006.12.012] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2006] [Revised: 11/14/2006] [Accepted: 12/24/2006] [Indexed: 11/25/2022]
Abstract
Human herpesvirus 6 (HHV-6), which is usually responsible for exanthem subitum in children, can reactivate from its latent form after primary infection. It has been implicated in hepatitis, pneumonitis, retinitis and severe infections of the central nervous system in both immunosuppressed and immunocompetent patients. However, involvement of HHV-6 in these infections has not yet been clearly demonstrated. We report the case of a patient presenting a bilateral uveitis from whom HHV-6 was isolated in both aqueous fluid and cerebrospinal fluid (CSF). No other pathogenic agents were found. Diagnosis by polymerase chain reaction (PCR) followed by sequencing of part of the genome revealed the presence of HHV-6 in both aqueous fluid and CSF. Serum IgM and IgG HHV-6 antibodies were significantly elevated in two successive examinations by immunofluorescence. Patient recovery following antiviral therapy suggested that a protocol based on foscarnet followed by ganciclovir was effective. HHV-6 may be responsible for uveo-meningitis. Diagnosis by PCR analysis is essential to identify HHV-6 and to initiate a specific antiviral therapy as fast as possible.
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Affiliation(s)
- Jérôme Maslin
- Laboratoire de Biologie Médicale, Groupement Médico Chirurgical Bouffard, SP Armées, Djibouti.
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Ward KN, Leong HN, Thiruchelvam AD, Atkinson CE, Clark DA. Human herpesvirus 6 DNA levels in cerebrospinal fluid due to primary infection differ from those due to chromosomal viral integration and have implications for diagnosis of encephalitis. J Clin Microbiol 2007; 45:1298-304. [PMID: 17229866 PMCID: PMC1865851 DOI: 10.1128/jcm.02115-06] [Citation(s) in RCA: 128] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The prevalence and concentration of human herpesvirus 6 (HHV-6) DNA in the cerebrospinal fluid (CSF) of the immunocompetent in primary infection was compared with that in viral chromosomal integration. Samples from 510 individuals with suspected encephalitis, 200 young children and 310 older children and/or adults, and 12 other patients were tested. HHV-6 DNA concentration (log(10) copies/ml) was measured in CSF, serum, and whole blood using PCR. Serum HHV-6 immunoglobulin G antibody was measured by indirect immunofluorescence. Primary infection was defined by antibody seroconversion and/or a low concentration of HHV-6 DNA (<3.0 log(10) copies/ml) in a seronegative serum. Chromosomal integration was defined by a high concentration of viral DNA in serum (>/=3.5 log(10) copies/ml) or whole blood (>/=6.0 log(10) copies/ml). The prevalences of CSF HHV-6 DNA in primary infection and chromosomal integration were 2.5% and 2.0%, respectively, in the young children (<2 years) and 0% and 1.3%, respectively, in the older children and/or adults. The mean concentration of CSF HHV-6 DNA in 9 children with primary infection (2.4 log(10) copies/ml) was significantly lower than that of 21 patients with viral chromosomal integration (4.0 log(10) copies/ml). Only HHV-6B DNA was found in primary infection, whereas in viral integration, 4 patients had HHV-6A and 17 patients HHV-6B. Apart from primary infection, chromosomal integration is the most likely cause of HHV-6 DNA in the CSF of the immunocompetent. Our results show that any diagnosis of HHV-6 encephalitis or other type of active central nervous system infection should not be made without first excluding chromosomal HHV-6 integration by measuring DNA load in CSF, serum, and/or whole blood.
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MESH Headings
- Adult
- Antibodies, Viral/analysis
- Blood/virology
- Cerebrospinal Fluid/virology
- Child, Preschool
- Chromosomes/virology
- DNA, Viral/cerebrospinal fluid
- Encephalitis, Viral/diagnosis
- Encephalitis, Viral/virology
- Female
- Fluorescent Antibody Technique, Indirect
- Herpesvirus 6, Human/immunology
- Herpesvirus 6, Human/isolation & purification
- Herpesvirus 6, Human/physiology
- Humans
- Immunoglobulin G/analysis
- Infant
- Infant, Newborn
- Middle Aged
- Polymerase Chain Reaction
- Prevalence
- Roseolovirus Infections/diagnosis
- Roseolovirus Infections/virology
- Serum/virology
- Virus Integration
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Affiliation(s)
- Katherine N Ward
- Centre for Virology, Division of Infection and Immunity, Royal Free and University College Medical School (UCL campus), Windeyer Institute of Medical Sciences, 46 Cleveland Street, London W1T 4JF, United Kingdom.
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Leong HN, Tuke PW, Tedder RS, Khanom AB, Eglin RP, Atkinson CE, Ward KN, Griffiths PD, Clark DA. The prevalence of chromosomally integrated human herpesvirus 6 genomes in the blood of UK blood donors. J Med Virol 2007; 79:45-51. [PMID: 17133548 DOI: 10.1002/jmv.20760] [Citation(s) in RCA: 160] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
A lesser-recognized form of human herpesvirus 6 (HHV-6) persistence is integration of the viral genome in a host chromosome and high viral copy numbers in blood or sera are characteristic of this phenomenon. A cross-sectional study was performed to determine the frequency of high HHV-6 viral loads in whole blood (>6 log(10) copies/ml) in a population of blood donors in London, UK. Blood samples from 500 anonymized blood donors were collected from one donation center, DNA extracted, and quantitative realtime PCR used to measure viral load. Four samples (0.8%) were found to have high viral copy numbers of HHV-6 (median 6.7 log(10) copies/ml; range 6.5- 6.9 log(10) copies/ml). Cellular DNA was also quantitated using qRT-PCR for beta-globin. By comparing these two results, we calculated that there were between two and five copies of HHV-6 present per cell in these four donors. The median viral load detected in plasma from the four individuals was 3.8 log(10) copies/ml (range 3.5-4.0 log(10) copies/ml). All samples were HHV-6 variant B. In addition, a retrospective analysis of all diagnostic blood samples performed for HHV-6 in our center showed a prevalence of 2.9% of high viral loads characteristic of integration. In conclusion, high viral copy numbers of HHV-6, representing a population of viral integration, is detected in 0.8% of UK blood donors. The presence of high HHV-6 viral loads in healthy normal individuals reiterates the need to consider the confounding effect of HHV-6 viral integration in any laboratory diagnosis of HHV-6 infection.
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Affiliation(s)
- Hoe Nam Leong
- Division of Infection and Immunity, Centre for Virology, Hampstead Campus, Royal Free and University College Medical School, London, UK
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Ward KN, Leong HN, Nacheva EP, Howard J, Atkinson CE, Davies NWS, Griffiths PD, Clark DA. Human herpesvirus 6 chromosomal integration in immunocompetent patients results in high levels of viral DNA in blood, sera, and hair follicles. J Clin Microbiol 2006; 44:1571-4. [PMID: 16597897 PMCID: PMC1448653 DOI: 10.1128/jcm.44.4.1571-1574.2006] [Citation(s) in RCA: 167] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2006] [Accepted: 02/13/2006] [Indexed: 11/20/2022] Open
Abstract
Six immunocompetent patients with human herpesvirus 6 (HHV-6) chromosomal integration had HHV-6 and beta-globin DNA quantified in various samples by PCR. The mean HHV-6 DNA concentration (log(10) copies/milliliter) in blood was 7.0 (>/=1 HHV-6 DNA copies/leukocyte), and in serum it was 5.3 (>/=1 HHV-6 DNA copies/lysed cell). The mean HHV-6 DNA load (log(10) copies)/hair follicle was 4.2 (>/=1 copies/hair follicle cell), demonstrating that viral integration is not confined to blood cells. The characteristically high HHV-6 DNA levels in chromosomal integration may confound laboratory diagnosis of HHV-6 infection and should be given due consideration.
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Affiliation(s)
- Katherine N Ward
- Centre for Virology, Division of Infection and Immunity, Royal Free and University College Medical School (UCL campus), Windeyer Institute of Medical Sciences, 46 Cleveland St., London W1T 4JF, United Kingdom.
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24
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Tuke PW, Hawke S, Griffiths PD, Clark DA. Distribution and quantification of human herpesvirus 6 in multiple sclerosis and control brains. Mult Scler 2005; 10:355-9. [PMID: 15327029 DOI: 10.1191/1352458504ms1057oa] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Multiple sclerosis (MS) is thought to be precipitated by environmental factors, potentially including viruses, in genetically susceptible individuals and recently human herpesvirus 6 (HHV-6) has been associated with the disease. We have analysed post mortem brain for the presence, variant type and quantity of HHV-6 by PCR. A total of 124 samples from seven anatomically defined regions of brain were tested from MS cases and controls. HHV-6 DNA was detected in 41% and 44% of MS case and control samples. The median viral loads were 11 and 9 genome copies/microg DNA in cases and controls respectively and the viral load was not increased in lesions. Except in one instance, the HHV-6 DNA detected was variant B. There was no apparent difference in the distribution of HHV-6 DNA in the brains of MS cases versus controls, nor between normal appearing and lesional tissue in MS cases. Periventricular regions of the brain were more frequently positive for HHV-6 DNA in both MS cases and controls, although this difference was not statistically significant. These studies confirm the neurotropism of HHV-6 but do not demonstrate differences in the distribution, variant type or quantity of HHV-6 in brains from patients with MS versus controls.
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Affiliation(s)
- P W Tuke
- Centre for Virology, Department of Infection, Royal Free and University College Medical School of UCL, Hampstead Site, Rowland Hill Street, London NW3 2PF, UK
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25
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Ward KN, Thiruchelvam AD, Couto-Parada X. Unexpected occasional persistence of high levels of HHV-6 DNA in sera: Detection of variants A and B. J Med Virol 2005; 76:563-70. [PMID: 15977239 DOI: 10.1002/jmv.20399] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Previously it was thought that in the immunocompetent human herpesvirus-6 [HHV-6] DNA was present transiently in serum during early primary infection but not thereafter. In this study, HHV-6 serum IgG avidity was detected by immunofluorescence and HHV-6 variants A/B [HHV-6A/B] serum DNA by semi-quantitative PCR [titre-log(10) copies/ml] in: (a) young children <3 years old from an encephalitis Survey, and a control Anonymised Serum Bank and (b) children/adults referred for diagnosis. The results showed that 11 out of 15 children [all <2 years] with primary infection proven by seroconversion had transient low levels of serum HHV-6B DNA [mean titre 2.6]. However, 3.3% (6/184) of Survey Children had significantly higher levels [mean titre 5.3; 2 HHV-6A; 4 HHV-6B; P < 0.001]. Similarly high level serum DNA [mean titre 4.0; 4 HHV-6A; 6 HHV-6B] was found in 1.5% (10/653) of the Serum Bank Children. Moreover, seven young children <3 years old [four Survey Children and three referred for diagnosis] had high titre serum HHV-6 DNA [mean 4.8] persisting i.e., in all available samples [median 186 days]. Three older children >3 years old and 4 adults [3 of whom were the mothers of 3 of the young children with persisting HHV-6] also had persisting high titre viral DNA [mean 4.2; median 108 days]. Thus in contrast to acute primary infection, where only HHV-6B DNA is found transiently, both HHV-6A and B DNA persist in serum at high titre in occasional individuals of all ages. The significance of this newly described phenomenon in relation to diagnosis, clinical consequences and congenital infection are discussed.
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Affiliation(s)
- Katherine N Ward
- Department of Virology, Royal Free and University College Medical School, Windeyer Institute of Medical Sciences, 46 Cleveland Street, London, United Kingdom.
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26
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Boutolleau D, Bonduelle O, Sabard A, Devers L, Agut H, Gautheret-Dejean A. Detection of human herpesvirus 7 DNA in peripheral blood reflects mainly CD4+ cell count in patients infected with HIV. J Med Virol 2005; 76:223-8. [PMID: 15834866 DOI: 10.1002/jmv.20345] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The opportunistic behavior and the potential interactions of human herpesvirus 7 (HHV-7) with human immunodeficiency virus (HIV)-1 in HIV-1-infected patients were investigated in comparison with HHV-6, another human roseolovirus. Roseolovirus DNAs were detected and quantified in peripheral blood mononuclear cells (PBMCs) from 198 HIV-seronegative healthy blood donors, 38 HIV-1-infected patients classified as long-term non-progressors, and 99 HIV-1-infected patients classified as progressors. The rate of HHV-7 DNA detection was higher in healthy donors (78%) than in long-term non-progressors (47%; P = 0.0003) or in progressors (52%; P < 0.0001). HHV-7 cell load was higher in healthy donors (median: 212 EqCop/10(6) PBMCs) and in long-term non-progressors (median: 105 EqCop/10(6) PBMCs) than in progressors (median: 48 EqCop/10(6) PBMCs; P < 0.0001 and P = 0.015, respectively). Among progressors, HHV-7 detection was correlated positively with the CD4(+) T-lymphocyte count (P = 0.028). Neither HHV-7 detection rate nor cell load was correlated with the HIV-1 plasma load. As a whole, HHV-6 detection rate and cell load were lower than the HHV-7 counterparts, albeit exhibiting similar differences between healthy donors, long-term non-progressors, and progressors. In conclusion, HHV-7 infection does not appear to be stimulated by HIV-1 infection, nor interact with it. Rather, HHV-7 detection rate and cell load reflect CD4(+) T-lymphocyte count, with higher values in healthy donors and long-term non-progressors than in progressors.
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Affiliation(s)
- David Boutolleau
- Laboratoire de Virologie, UPRES EA 2387, Groupe Hospitalier Pitié-Salpêtrière, Paris, France.
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Abstract
OBJECTIVE To examine whether: (1) congenital human herpesvirus 6 (HHV6) and human herpesvirus 7 (HHV7) infections occur; whether (2) their manifestations differ from postnatal infections; and whether (3) HHV6 and HHV7 infections differ despite their close relatedness. STUDY DESIGN HHV6 and HHV7 infections acquired congenitally and postnatally in normal children were compared using viral isolation, serology, reverse-transcription polymerase chain reaction (RT-PCR) and nested DNA-PCR for HHV6 variant A (HHV6A), HHV6 variant B (HHV6B), and HHV7. RESULTS HHV6 DNA was detected in 57 (1%) of 5638 cord bloods. HHV7 DNA, however, was not detected in 2129 cord bloods. Congenital HHV6 infections differed from postnatal infections, which were acute febrile illnesses. Congenital infections were asymptomatic, 10% demonstrated reactivation at birth, and HHV6 DNA persistence in follow-up blood samples was significantly more frequent. One-third of congenital infections were HHV6A, whereas all postnatal infections were HHV6B. CONCLUSIONS Congenital HHV6 infections occurred in 1% of births, similar to the rate for cytomegalovirus infection. Congenital infections were clinically and virologically distinct from postnatal infections. Congenital HHV7 infections, however, were not detected, suggesting considerable differences in transmission and pathogenesis in these closely related beta-herpesviruses.
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Wang G, Krueger GRF, Buja LM. Mathematical model to simulate the cellular dynamics of infection with human herpesvirus-6 in EBV-negative infectious mononucleosis. J Med Virol 2004; 71:569-77. [PMID: 14556271 DOI: 10.1002/jmv.10522] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Acute infection with human herpesvirus-6 induces physiological cell proliferation in persons without major immune deficiency. It thus can serve as a parameter to validate a mathematical model designed to simulate cell proliferation under physiological and pathological conditions. Such a mathematical model is presented to simulate various cell changes of the T-cell immune system during the course of HHV-6 infection. Model development follows several steps, beginning with a basic model containing physiological T-cell pools to the introduction of infectious stimuli in the final model. A search algorithm designed to optimize the system parameters, as well as initial variables of the model, is presented. The results of simulation runs for acute HHV-6 infection of the final computational model correspond well to the data, as documented in human patients; they suggest that the computational model presented for the simulation of T-cell levels in a given viral infection may well serve as a tool for similar studies of other viral infections, including those that lead to cellular aplasia or neoplasia.
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Affiliation(s)
- Guanyu Wang
- Center for Computational Biomedicine, School of Health Information Sciences, University of Texas Health Science Center, Houston, Texas 77054, USA.
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Clark DA, Griffiths PD. Human herpesvirus 6: relevance of infection in the immunocompromised host. Br J Haematol 2003; 120:384-95. [PMID: 12580952 DOI: 10.1046/j.1365-2141.2003.04048.x] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- Duncan A Clark
- Department of Virology, Royal Free and University College Medical School of UCL, Royal Free Campus, London, UK.
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31
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Benito N, Moreno A, Pumarola T, Marcos MA. Virus del herpes humano tipo 6 y tipo 7 en receptores de trasplantes. Enferm Infecc Microbiol Clin 2003; 21:424-32. [PMID: 14525708 DOI: 10.1016/s0213-005x(03)72980-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Recent years have witnessed a growing interest in the role of human herpesvirus (HHV) type 6 and type 7 as emerging pathogens or copathogens in transplant recipients. Both HHV-6 and HHV-7 belong to the beta-herpesvirus family and are closely related to another member of the family, cytomegalovirus. After the primary infection, these viruses remain latent in the human host and can reactivate after transplantation. Various clinical processes such as fever, rash, pneumonitis, encephalitis, hepatitis, and myelosuppression have been described in association with herpesvirus. Moreover, a growing body of evidence suggests that the major impact of HHV-6 and HHV-7 reactivation in transplantation is related to indirect effects, such as their association with cytomegalovirus disease, increased opportunistic infections, and graft dysfunction and rejection. The pathogenesis of HHV-6 and HHV-7 during the post-transplantation period, the methods used for their diagnosis, and the evaluation of antiviral drugs and strategies for their prevention and treatment are now the subject of extensive research.
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Affiliation(s)
- Natividad Benito
- Servicio de Infecciones. Institut Clínic d'Infeccions i Inmunologia. Hospital Clínic Universitari-IDIBAPS. Barcelona. España.
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Byington CL, Zerr DM, Taggart EW, Nguy L, Hillyard DR, Carroll KC, Corey L. Human herpesvirus 6 infection in febrile infants ninety days of age and younger. Pediatr Infect Dis J 2002; 21:996-9. [PMID: 12442018 DOI: 10.1097/00006454-200211000-00004] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND The importance of human herpesvirus 6 (HHV-6) as a pathogen in febrile infants </=90 days of age is unknown. OBJECTIVE To determine whether febrile infants 90 days of age and younger evaluated for sepsis have evidence of HHV-6 DNA in plasma or cerebrospinal fluid (CSF). METHODS Febrile infants </=90 days of age were tested for HHV-6 DNA using a real time quantitative fluorescent probe polymerase chain reaction assay. RESULTS Eighty samples from 47 infants were tested for HHV-6 DNA; 5 of 47 infants (10.6%) had HHV-6 DNA in plasma. In 2 of the 5 infants with HHV-6 DNA in plasma, HHV-6 DNA was also detected in the CSF. Both infants with evidence of HHV-6 DNA in plasma and CSF had HHV-6 Variant A infection. The quantity of HHV-6 DNA detected ranged from 70 to 169,000 DNA copies/ml. One infant with HHV-6 variant B infection had concomitant Escherichia coli bacteremia and urinary tract infection. CONCLUSIONS Approximately 10% of febrile infants </=90 days of age evaluated for sepsis had evidence of HHV-6 infection. HHV-6 Variant A and B infections were seen in these young infants. HHV-6 DNA was found in infants with and without another explanation for fever. Quantification of viral DNA may be important in determining the relevance of HHV-6 DNA in clinical specimens.
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Wang FZ, Larsson K, Linde A, Ljungman P. Human herpesvirus 6 infection and cytomegalovirus-specific lymphoproliferative responses in allogeneic stem cell transplant recipients. Bone Marrow Transplant 2002; 30:521-6. [PMID: 12379892 DOI: 10.1038/sj.bmt.1703657] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2001] [Accepted: 06/11/2002] [Indexed: 11/09/2022]
Abstract
The aim of this study was to investigate the effects of HHV-6 DNAemia on the CMV specific lymphoproliferative response after allogeneic stem cell transplantation. Twenty-one allogeneic stem cell transplantation (allo-SCT) patients were included in the study. The patients were either CMV seropositive and/or had CMV seropositive donors. We studied the effects of HHV-6 infection, documented by PCR, on CMV-specific lymphocyte proliferation response and on CMV infection documented by PCR. HHV-6 DNAemia correlated with the absence of CMV-specific lymphocyte proliferation responses after allo-SCT. Three of nine patients with persistent HHV-6 DNA had a CMV-specific lymphocyte proliferative response compared to 11 of 12 patients without persistent HHV-6 DNAemia (P = 0.02). Patients with higher HHV-6 DNA levels (>100 copies) were more likely than those with lower copy numbers not to develop a CMV-specific immune response (six of nine vs one of eight; P < 0.05). Patients who were repeatedly HHV-6 positive in three or more consecutive blood samples were also more likely to need repeated courses of preemptive antiviral therapy against CMV during the first 6 months after transplantation (P < 0.001). Our data indicate the possibility that HHV-6 can suppress the development of CMV-specific immune responses and thereby could predispose to development of late CMV disease.
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Affiliation(s)
- F-Z Wang
- Department of Hematology, Huddinge University Hospital, Karolinska Institutet, Stockholm, Sweden
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34
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High incidence of human herpesvirus 6 infection with a high viral load in cord blood stem cell transplant recipients. Blood 2002. [DOI: 10.1182/blood.v100.6.2005] [Citation(s) in RCA: 119] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
AbstractHuman herpesvirus 6 (HHV-6) infection in recipients of cord blood stem cell transplants (CBSCTs) was estimated by semiquantitative and real-time quantitative polymerase chain reaction (PCR) and reverse-transcription PCR. Of the CBSCT recipients, 7 (70%) of 10 had active HHV-6 infection after transplantation, and all 7 were inferred from their age to have already had a primary infection. Because HHV-6 DNA is seldom detected in cord blood, these cases were considered likely to represent reactivation. In contrast, the 3 patients without HHV-6 infection were all believed to be naive regarding HHV-6 primary infection because of their age and the results of PCR assays given before the transplantation procedure. The incidence of HHV-6 infection after transplantation was significantly higher (P < .05) than after bone marrow (BM) transplantation and peripheral blood stem cell (PBSC) transplantation, when recipients without primary HHV-6 infection prior to transplantation were excluded (CBSCT, 100%; BMT/PBSCT, 56.3%). Real-time PCR revealed a higher level of viral DNA in the peripheral blood mononuclear cells from CBSCT recipients than from BMT/PBSCT recipients or patients with exanthem subitum (P < .05). HHV-6 mRNA of the U79/80gene was also detected by reverse-transcription PCR in all analyzed patients with HHV-6 infection. Its detection was correlated with the emergence of viral DNA in the plasma and symptoms such as fever and rash. Thus, HHV-6 infection was more frequent and the viral load was higher in CBSCT recipients with prior primary infection.
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Abstract
Human herpesvirus 6 (HHV-6) infection in recipients of cord blood stem cell transplants (CBSCTs) was estimated by semiquantitative and real-time quantitative polymerase chain reaction (PCR) and reverse-transcription PCR. Of the CBSCT recipients, 7 (70%) of 10 had active HHV-6 infection after transplantation, and all 7 were inferred from their age to have already had a primary infection. Because HHV-6 DNA is seldom detected in cord blood, these cases were considered likely to represent reactivation. In contrast, the 3 patients without HHV-6 infection were all believed to be naive regarding HHV-6 primary infection because of their age and the results of PCR assays given before the transplantation procedure. The incidence of HHV-6 infection after transplantation was significantly higher (P < .05) than after bone marrow (BM) transplantation and peripheral blood stem cell (PBSC) transplantation, when recipients without primary HHV-6 infection prior to transplantation were excluded (CBSCT, 100%; BMT/PBSCT, 56.3%). Real-time PCR revealed a higher level of viral DNA in the peripheral blood mononuclear cells from CBSCT recipients than from BMT/PBSCT recipients or patients with exanthem subitum (P < .05). HHV-6 mRNA of the U79/80gene was also detected by reverse-transcription PCR in all analyzed patients with HHV-6 infection. Its detection was correlated with the emergence of viral DNA in the plasma and symptoms such as fever and rash. Thus, HHV-6 infection was more frequent and the viral load was higher in CBSCT recipients with prior primary infection.
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Clark DA. Human herpesvirus 6 and human herpesvirus 7: emerging pathogens in transplant patients. Int J Hematol 2002; 76 Suppl 2:246-52. [PMID: 12430932 DOI: 10.1007/bf03165124] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Human herpesvirus 6 (HHV-6) and HHV-7 are two recently identified beta-herpesviruses, genetically related to human cytomegalovirus (CMV). Infection with both viruses is common worldwide with rates of seropositivity in adults over 90%. Infection with both viruses usually occurs in early childhood. In this age group HHV-6 is a cause of febrile illness including exanthem subitum, and likewise, primary HHV-7 infection has been associated with febrile illness. Similar to the other human herpesviruses, in particular CMV, the viruses have the potential for enhanced pathogenicity in the immunocompromised host. Active infection with both viruses is common following bone marrow or solid organ transplantation, most likely through reactivation of recipient's virus or re-infection considering their high prevalence in the population. Both viruses can be detected by PCR in the peripheral blood of healthy individuals and although the significance of blood-borne transmission is not clear, a preliminary study suggested that it was not significant for HHV-6. However, there is growing evidence that these viruses may be medically important in the post-transplant period. In bone marrow transplant patients HHV-6 has been associated with a range of clinical disease including encephalitis, interstitial pneumonitis, early and late graft failure and bone marrow suppression. There is also growing evidence for potential interactions among the beta-herpesviruses in liver and renal transplant patients. HHV-6 infection has been associated with an increased risk of developing CMV disease and opportunistic infections and HHV-7 infection has also been linked to an increased risk of CMV disease.
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Affiliation(s)
- Duncan A Clark
- Department of Virology, Royal Free and University College Medical School of UCL, London, UK
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Gautheret-Dejean A, Manichanh C, Thien-Ah-Koon F, Fillet AM, Mangeney N, Vidaud M, Dhedin N, Vernant JP, Agut H. Development of a real-time polymerase chain reaction assay for the diagnosis of human herpesvirus-6 infection and application to bone marrow transplant patients. J Virol Methods 2002; 100:27-35. [PMID: 11742650 DOI: 10.1016/s0166-0934(01)00390-1] [Citation(s) in RCA: 139] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
A quantitative real-time PCR assay was developed for human herpesvirus-6 (HHV-6) genome based on TaqMan technology. After choosing a region of interest into the U65-U66 genes of HHV-6 genome, its nucleotide sequence was determined among four HHV-6 strains (one variant A and three variants B) to exclude a variability of sensitivity due to interstrain sequence differences. A plasmid containing HHV-6 target sequences identical to those of reference type viruses was constructed with the aim of standardisation. This HHV-6 genomic quantitation assay has a threshold sensitivity of ten copy equivalents (EqCop) per reaction. In order to test the feasibility of this assay directly on human samples, the technique was applied to the quantitation of HHV-6 genome in 30 blood samples from healthy subjects as well as 31 blood samples and three samples of cerebrospinal fluid (CSF) from 21 bone marrow transplant (BMT) recipients and four patients with a haematological disease but not treated by bone marrow transplantation. HHV-6 load ranged between 0.00015 and 0.0008 equivalent DNA copy number (EqCop) per 100 peripheral blood mononuclear cells (PBMCs) in healthy subjects whereas it ranged from <10 to 7500 EqCop per 100 PBMCs, and from <10 to 415,820 EqCop per 100 microl of whole CSF in patients. The efficacy of treatment with antiherpetic drug was associated with a decrease of the viral load in the CSF of one patient. This method leads to relevant results in term of range of quantitation, sensitivity, and safety against contamination by amplicons, and might constitute a useful tool for the follow-up of BMT recipients particularly in the presence of antiherpetic therapy.
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Affiliation(s)
- Agnès Gautheret-Dejean
- Laboratoire de Virologie, UPRES EA 2387, Groupe Hospitalier Pitié-Salpêtrière, 83 boulevard de l'Hôpital, 75013 Paris, France.
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Abe T, Yoshikawa T, Ihira M, Suzuki K, Suga S, Nishida M, Nagata M, Asano Y. Quantitation of human herpesvirus 6 DNA in infant with exanthem subitum by microplate PCR-hybridization assay. Pediatr Int 2001; 43:372-8. [PMID: 11472582 DOI: 10.1046/j.1442-200x.2001.01401.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Quantitative analysis of human herpesvirus 6 (HHV-6) genome is important for monitoring active virus infection. The purpose of our study is to evaluate the reliability of a hybridization-based microtiter plate assay (polymerase chain reaction enzyme-linked immunosorbent assay (PCR ELISA)) for quantifying the virus genome. METHODS Semiquantitative analysis of the virus genome was carried out in 31 (18 male and 13 female) infants with primary HHV-6 infection. If the HHV-6 virus could be isolated from the peripheral blood mononuclear cells (PBMC), the infants were defined as being infected with HHV-6. The PCR ELISA method was used to determine the virus load. A titration of the virus was also carried out in the samples obtained during the acute phase of exanthem subitum. RESULTS Specificity of the method was demonstrated by a lack of amplification of human herpesvirus 7 and cytomegalovirus DNA. The upper and lower detection limits of the method were 58 and 5800 copies of the virus genome, respectively. The quantity of HHV-6 DNA in the PBMC during the acute phase (879 +/- 975 copies/10(4) PBMC) was significantly higher than during the convalescent phase (54 +/- 76 copies/10(4) PBMC). Furthermore, the virus load in acute phase plasma (53 +/- 75 copies/microL) was also significantly higher than in the convalescent phase samples (2 +/- 9 copies/microL). Virus load in both PBMC and plasma gradually increased after the onset of exanthem subitum until about day 3 to 4 of the illness, but then decreased quickly. However, there was no significant association between virus load and the numbers of infected cells. CONCLUSION Virus load in both PBMC and plasma gradually increased after the onset of exanthem subitum until about day 3 and day 4 of the illness, respectively, then it decreased quickly. These results indicate that our PCR ELISA system is reliable for monitoring active HHV-6 infection in vivo.
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Affiliation(s)
- T Abe
- Department of Pediatrics, Fujita Health University Hospital, Toyoake, Aichi, Japan
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39
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Fryer JF, Griffiths PD, Fishman JA, Emery VC, Clark DA. Quantitation of porcine cytomegalovirus in pig tissues by PCR. J Clin Microbiol 2001; 39:1155-6. [PMID: 11230447 PMCID: PMC87893 DOI: 10.1128/jcm.39.3.1155-1156.2001] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A quantitative-competitive PCR for the quantification of porcine cytomegalovirus (PCMV) was developed. The virus was detected in a variety of pig organs (including potential xenotransplant donations), with viral loads ranging from <10 to 97 genome copies/microg of DNA. This assay will have significant utility for studying the activation and replication of PCMV and in swine models for allo- and xenotransplantation.
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Affiliation(s)
- J F Fryer
- Department of Virology, Royal Free and University College Medical School of UCL, Rowland Hill Street, London NW3 2PF, United Kingdom
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Khare MD. Human herpesvirus 6: its impact and influence on infectious diseases and their management. Expert Opin Pharmacother 2001; 2:213-21. [PMID: 11336581 DOI: 10.1517/14656566.2.2.213] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Human herpesvirus (HHV)-6 was discovered 15 years ago and was then grouped as a member of the family human herpesviridae. Its first clinical manifestation was identified 2 years later as the agent responsible for exanthem subitum. With the advent of newer molecular techniques, its diagnosis is easier and prospective studies have shown that it is the most common pathogen responsible for febrile illness in infants. In some infants, it is associated with febrile convulsions. Two subtypes, A and B, have been identified, B subtype commonly being responsible for primary infection in infants. Primary infection in healthy adults is rare. Most of the clinical manifestations are mild, self-limiting and rarely fatal. Reactivation of HHV-6 is frequently found in bone marrow as well as solid organ transplant recipients. HHV-6 has been shown to be an independent risk factor responsible for recurrence of cytomegalovirus infection, especially in solid organ transplants. In bone marrow transplant recipients, HHV-6 has been associated with various manifestations like marrow suppression and graft versus host disease, although most infections present as usually mild febrile illness with or without rash. It has been reported to cause encephalitis in transplant recipients. Although HHV-6 has been shown to be responsible for upregulation of HIV in vitro studies, its exact role in AIDS is yet to be defined. In addition to its neurotropic manifestation of febrile convulsion in infancy, it has been found in plaques in the brain of multiple sclerosis and progressive multifocal leukoencephalopathy. Further studies are needed before its role in the pathogenesis of these neurological illnesses can be established. Its lymphotropic feature was responsible for its discovery and now it has only been detected in some lesions of primary ocular mucosa associated lymphoid tissue lymphoma. As HHV-6 is found to be responsible for more and more illnesses, especially causing serious illnesses in the immunocompromised, it is becoming necessary to find effective treatment. Some agents, like cidofovir and phosphonoformic acid, are effective in in vitro studies and some have shown effectiveness in a clinical setting. Further studies are needed to identify its role in the pathogenesis of various neurological and malignant lesions and AIDS. Various treatment regimens should be tested in clinical scenario and especially in immunocompromised transplant recipients.
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Affiliation(s)
- M D Khare
- St. George's Hospital Medical School, Cranmer Terrace, London SW17 0RE, UK.
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41
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Ljungman P, Wang FZ, Clark DA, Emery VC, Remberger M, Ringden O, Linde A. High levels of human herpesvirus 6 DNA in peripheral blood leucocytes are correlated to platelet engraftment and disease in allogeneic stem cell transplant patients. Br J Haematol 2000. [DOI: 10.1046/j.1365-2141.2000.02422.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Locatelli G, Santoro F, Veglia F, Gobbi A, Lusso P, Malnati MS. Real-time quantitative PCR for human herpesvirus 6 DNA. J Clin Microbiol 2000; 38:4042-8. [PMID: 11060066 PMCID: PMC87539 DOI: 10.1128/jcm.38.11.4042-4048.2000] [Citation(s) in RCA: 110] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2000] [Accepted: 07/28/2000] [Indexed: 01/22/2023] Open
Abstract
The diagnosis of human herpesvirus 6 (HHV-6) infection represents a complex issue because the most widely used diagnostic tools, such as immunoglobulin G antibody titer determination and qualitative DNA PCR with blood cells, are unable to distinguish between latent (clinically silent) and active (often clinically relevant) infection. We have developed a new, highly sensitive, quantitative PCR assay for the accurate measurement of HHV-6 DNA in tissue-derived cell suspensions and body fluids. The test uses a 5' nuclease, fluorogenic assay combined with real-time detection of PCR amplification products with the ABI PRISM 7700 sequence detector system. The sensitivity of this method is equal to the sensitivity of a nested PCR protocol (lower detection limit, 1 viral genome equivalent/test) for both the A and the B HHV-6 subgroups and shows a wider dynamic range of detection (from 1 to 10(6) viral genome equivalents/test) and a higher degree of accuracy, repeatability, and reproducibility compared to those of a standard quantitative-competitive PCR assay developed with the same reference DNA molecule. The novel technique is versatile, showing the same sensitivity and dynamic range with viral DNA extracted from different fluids (i.e., culture medium or plasma) or from tissue-derived cell suspensions. Furthermore, by virtue of its high-throughput format, this method is well suited for large epidemiological surveys.
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Affiliation(s)
- G Locatelli
- Unit of Human Virology, DIBIT, San Raffaele Scientific Institute, 20132 Milan, Italy
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Mattes FM, McLaughlin JE, Emery VC, Clark DA, Griffiths PD. Histopathological detection of owl's eye inclusions is still specific for cytomegalovirus in the era of human herpesviruses 6 and 7. J Clin Pathol 2000; 53:612-4. [PMID: 11002765 PMCID: PMC1762915 DOI: 10.1136/jcp.53.8.612] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
BACKGROUND Cytomegalovirus (CMV) is the prototype member of the beta-herpesvirinae, which can cause multiple organ dysfunction in the immunocompromised host. Human herpesvirus 6 (HHV-6) and HHV-7 are newer members of the beta-herpesvirinae that can cause febrile illness in young children and are also possible pathogens in the immunocompromised patient. AIM CMV is detected in histopathological sections by visualisation of owl's eye inclusion bodies. The aim of this study was to quantify the relation between CMV, HHV-6, and HHV-7 viral loads and the presence of owl's eye inclusions in histological sections. METHODS Histopathological examination of postmortem material and recording of owl's eye inclusion bodies were performed. CMV, HHV-6, and HHV-7 were detected by qualitative and quantitative polymerase chain reaction (PCR) from the same postmortem samples. Statistical analysis of the histopathological and PCR results was performed. RESULTS There was a significant association between the detection of owl's eye inclusion bodies and positive CMV PCR (p < 0.001); the median CMV viral load was significantly higher in samples that were positive for owl's eye inclusions (p < 0.001). No association was found between the presence of owl's eye inclusions and HHV-6 or HHV-7 positivity. CONCLUSION Histological detection of owl's eye inclusion bodies is an insensitive but highly specific method for detecting CMV organ involvement. Owl's eye inclusion bodies are not associated with HHV-6 or HHV-7 infection.
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Affiliation(s)
- F M Mattes
- Department of Virology, Royal Free and University College Medical School, London, UK.
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Kidd IM, Clark DA, Sabin CA, Andrew D, Hassan-Walker AF, Sweny P, Griffiths PD, Emery VC. Prospective study of human betaherpesviruses after renal transplantation: association of human herpesvirus 7 and cytomegalovirus co-infection with cytomegalovirus disease and increased rejection. Transplantation 2000; 69:2400-4. [PMID: 10868648 DOI: 10.1097/00007890-200006150-00032] [Citation(s) in RCA: 112] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
BACKGROUND Human herpesvirus 6 (HHV-6) and HHV-7 are two lymphotropic herpesviruses, which, like cytomegalovirus (CMV), have the potential to be pathogenic in immunocompromised individuals. We have conducted a prospective investigation to compare the natural history of HHV-6 and HHV-7 infection with that of CMV after renal transplantation. METHODS Polymerase chain reaction was used to identify infections and quantify the viral load of CMV, HHV-6, and HHV-7 in peripheral blood samples from 52 renal transplant recipients. Betaherpesvirus infections were related to defined clinical criteria obtained by detailed examination of the clinical records of each patient for the immediate 120-day posttransplant period. RESULTS CMV was the most commonly detected virus after transplant (58% of patients), followed by HHV-7 (46%) and HHV-6 (23%). Examining the time to first polymerase chain reaction positivity, HHV-7 infection was detected earlier than CMV (P=0.05). The median maximum CMV viral load was significantly higher than those for HHV-6 (P=0.01) and HHV-7 (P<0.0001) and a trend for HHV-7 viral load to be greater than HHV-6 (P=0.08). Clinicopathological analyses revealed that, in those patients with rejection, HHV-7 was associated with more episodes of rejection (P=0.02). In addition, there was a significant increase in CMV disease occurring in patients with CMV and HHV-7 co-infection compared to those with CMV infection only (P=0.04). CONCLUSIONS HHV-7 should be further investigated as a possible co-factor in the development of CMV disease in renal transplant patients and may potentially exacerbate graft rejection. No clear pathological role was observed for HHV-6.
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Affiliation(s)
- I M Kidd
- Department of Virology, Royal Free and University College Medical School of University College London, United Kingdom
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Blumberg BM, Mock DJ, Powers JM, Ito M, Assouline JG, Baker JV, Chen B, Goodman AD. The HHV6 paradox: ubiquitous commensal or insidious pathogen? A two-step in situ PCR approach. J Clin Virol 2000; 16:159-78. [PMID: 10738136 DOI: 10.1016/s1386-6532(99)00084-0] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Progressive multifocal leukoencephalopathy (PML) and multiple sclerosis (MS) are demyelinative diseases of the central nervous system (CNS). PML occurs mostly in individuals with AIDS-impaired immunity and is thought to be caused by JC polyoma virus (JCV). In MS a neurotrophic virus trigger is suspected, but the precise etiology remains unknown. Human herpesvirus 6 (HHV6) is a ubiquitous, commensal and usually benign beta-herpesvirus. Some researchers have found evidence for HHV6 infection in MS plaques and sera. We recently demonstrated a high frequency of cells containing HHV6 genome in PML lesions, as well as co-infection of oligodendrocytes by JCV and HHV6. This suggests that HHV6 may be a co-factor in the etiology of PML, and raises questions about its role in other demyelinative diseases. OBJECTIVES To determine the prevalence and cellular localization of HHV6, JCV and HIV-1 infected cells in PML, MS, AIDS and control CNS tissues, and their potential relationship with disease. STUDY DESIGN An unconventional, sensitive two-step in situ polymerase chain reaction (ISPCR) procedure was used to amplify and detect HHV6, JCV and HIV-1 genomic DNAs in formalin fixed, paraffin-embedded archival CNS tissues. HHV6, JCV and HIV-1 gene expression was detected by ICC for HHV6 p41 and gp101, JCV large T, and HIV-1 p24 gag and NEF proteins. RESULTS A high frequency of HHV6 genome was consistently detected in both PML and MS white matter lesional cells; a peri-lesional concentration was notable. HHV6 was found mainly in oligodendrocytes, but neurons were also infected. HHV6 was present in larger amounts than JCV in PML lesions, while more HIV-1 than HHV6 was present in AIDS. Variable amounts of HHV6 genome were detected in normal, AIDS and other control brains; the frequency of infected cells tended to increase with patient age. CONCLUSIONS High concentrations of HHV6 genome in association with PML and MS lesions, open the possibility that HHV6 activation may play a role in the pathogenesis of these demyelinative diseases.
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Affiliation(s)
- B M Blumberg
- VA Bio-Medical Research Institute, Building 7, East Orange VA Medical Center, 385 Tremont Avenue, East Orange, NJ, USA.
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Abstract
Human herpesvirus 6 (HHV-6), a member of the beta-herpesvirinae subfamily, is highly seroprevalent, has a worldwide distribution, and infection usually occurs within the first two years of life. In this age group, HHV-6 causes febrile illness including exanthem subitum with seizures a recognised complication. The virus is predominantly T lymphotropic although it can infect a variety of cell types in vitro and CD46 has recently been identified as a cellular receptor. The virus persists in the host, with a latent state proposed in monocytes and bone marrow progenitor cells, and chronic infection in salivary glands. The virus is pathogenic in the post transplantation period and may be a cofactor in the progression of HIV disease. The virus has also been associated with multiple sclerosis (MS), with the virus detected in oligodendrocytes particularly in plaque regions. The role of HHV-6 in MS remains controversial and a more extensive understanding of its neurotropism and association with disease is required. Two variants of HHV-6 exist (A and B) and comparison of their complete nucleotide sequences shows the genomes to be colinear, with a high degree of homology. Variation in specific regions of the genome is more extensive and probably accounts for biological and pathological differences. Almost exclusively, variant B is associated with febrile illness in childhood and is the predominant variant detected in healthy individuals. The epidemiology of HHV-6A infection needs to be better defined, although it is significantly less prevalent. Biological, genetic, epidemiological and pathological findings suggest that the two variants are divergent.
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Affiliation(s)
- D A Clark
- Department of Virology, Royal Free and University College Medical School, London, UK
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47
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Affiliation(s)
- W Preiser
- Department of Virology, Royal Free and University College Medical School, London
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Griffiths PD, Ait-Khaled M, Bearcroft CP, Clark DA, Quaglia A, Davies SE, Burroughs AK, Rolles K, Kidd IM, Knight SN, Noibi SM, Cope AV, Phillips AN, Emery VC. Human herpesviruses 6 and 7 as potential pathogens after liver transplant: prospective comparison with the effect of cytomegalovirus. J Med Virol 1999; 59:496-501. [PMID: 10534732 DOI: 10.1002/(sici)1096-9071(199912)59:4<496::aid-jmv12>3.0.co;2-u] [Citation(s) in RCA: 133] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Because cytomegalovirus (CMV) is an important opportunistic infection after liver transplant, we conducted a prospective study to see if the same applied to human herpesviruses (HHV)-6 and -7. We used polymerase chain reaction (PCR) methods optimised to detect active, not latent, infection and studied patients not receiving antiviral prophylaxis for CMV. Post-transplant, 536 blood samples were tested by PCR (median 7; range 4-50). Active infection with CMV was detected in 28/60 (47%), HHV-6 in 19/60 (32%), and HHV-7 in 29/60 (48%) of patients. The PCR-positive samples were tested by quantitative-competitive PCR to measure the virus load of each betaherpesvirus. The median peak virus load for CMV was significantly greater than that for HHV-6 or HHV-7. Detailed clinicopathological analyses for the whole population showed that CMV and HHV-6 were each significantly associated with biopsy-proven graft rejection. Individual case histories suggested that HHV-6 and HHV-7 may be the cause of some episodes of hepatitis and pyrexia. It is concluded that HHV-6 is a previously unrecognized contributor to the morbidity of liver transplantation, that HHV-7 may also be important and that both viruses should be included in the differential diagnosis of graft dysfunction.
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Affiliation(s)
- P D Griffiths
- Department of Virology, Royal Free Hospital and Royal Free and University College Medical School, London, England
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49
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Pathogenic role of human herpesvirus 6 in transplantation. Curr Opin Organ Transplant 1999. [DOI: 10.1097/00075200-199909000-00017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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50
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Ohyashiki JH, Abe K, Ojima T, Wang P, Zhou CF, Suzuki A, Ohyashiki K, Yamamoto K. Quantification of human herpesvirus 6 in healthy volunteers and patients with lymphoproliferative disorders by PCR-ELISA. Leuk Res 1999; 23:625-30. [PMID: 10400183 DOI: 10.1016/s0145-2126(99)00079-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
To determine whether actual numbers of human herpesvirus 6 (HHV-6) genome in hematologic neoplasias are associated with disease condition, we developed a quantitative PCR-ELISA for detection of HHV-6. The amount of viral DNA was determined using externally amplified known amounts of the plasmid DNA containing the viral target sequences. First, we determined a viral burden in peripheral blood leukocytes obtained from 23 healthy volunteers and four specimens of lymph nodes with reactive hyperplasia. Using 1 microg of DNA, the prevalence of HHV-6 was 43.4% (10/23), ranging from 0 to 100 HHV-6 genomes in blood obtained from healthy volunteers. The amounts of HHV-6 genomes were < 10 in four non-neoplastic lymph node specimens. We next examined the amount of viral DNA in 21 blood specimens and 19 lymph node specimens obtained from patients with lymphoproliferative diseases (LPD) at the time of diagnosis. The number of HHV-6 genomes in most of the B-cell lymphoma was < 5 in both blood and lymph node specimens, however, two lymph node specimens obtained from immunoblastic lymphadenopathy (IBL) and T-cell lymphoma had very high levels of HHV-6 viral DNA (3705 and 810, respectively). We also found that HHV-6 genomes in peripheral blood were more than 1000 in two patients with chronic lymphocytic leukemia. For all LPD patients combined, there were significantly higher levels of viral DNA (200.6 +/- 654.8 HHV-6 genomes per 1 microg purified DNA) compared to those in healthy volunteers (10.0 +/- 21.0 HHV-6 genomes per 1 microg purified DNA) (P < 0.05). This study demonstrates that a high level of HHV-6 viral DNA is occasionally associated with LPD patients. Although it is still uncertain whether HHV-6 is related to the pathogenesis in LPD or not, our results suggest that measurement of HHV-6 genomes using PCR-ELISA may be useful not only to understand the mechanism of HHV-6 infection in hemopoietic neoplasia but also to manage the care of immnocompromised patients such as bone marrow transplant patients.
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Affiliation(s)
- J H Ohyashiki
- Department of Virology, Medical Research Institute, Tokyo Medical and Dental University, Japan.
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