1
|
Preiksaitis J, Allen U, Bollard CM, Dharnidharka VR, Dulek DE, Green M, Martinez OM, Metes DM, Michaels MG, Smets F, Chinnock RE, Comoli P, Danziger-Isakov L, Dipchand AI, Esquivel CO, Ferry JA, Gross TG, Hayashi RJ, Höcker B, L'Huillier AG, Marks SD, Mazariegos GV, Squires J, Swerdlow SH, Trappe RU, Visner G, Webber SA, Wilkinson JD, Maecker-Kolhoff B. The IPTA Nashville Consensus Conference on Post-Transplant lymphoproliferative disorders after solid organ transplantation in children: III - Consensus guidelines for Epstein-Barr virus load and other biomarker monitoring. Pediatr Transplant 2024; 28:e14471. [PMID: 37294621 DOI: 10.1111/petr.14471] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Revised: 12/10/2022] [Accepted: 01/02/2023] [Indexed: 06/11/2023]
Abstract
The International Pediatric Transplant Association convened an expert consensus conference to assess current evidence and develop recommendations for various aspects of care relating to post-transplant lymphoproliferative disorders after solid organ transplantation in children. In this report from the Viral Load and Biomarker Monitoring Working Group, we reviewed the existing literature regarding the role of Epstein-Barr viral load and other biomarkers in peripheral blood for predicting the development of PTLD, for PTLD diagnosis, and for monitoring of response to treatment. Key recommendations from the group highlighted the strong recommendation for use of the term EBV DNAemia instead of "viremia" to describe EBV DNA levels in peripheral blood as well as concerns with comparison of EBV DNAemia measurement results performed at different institutions even when tests are calibrated using the WHO international standard. The working group concluded that either whole blood or plasma could be used as matrices for EBV DNA measurement; optimal specimen type may be clinical context dependent. Whole blood testing has some advantages for surveillance to inform pre-emptive interventions while plasma testing may be preferred in the setting of clinical symptoms and treatment monitoring. However, EBV DNAemia testing alone was not recommended for PTLD diagnosis. Quantitative EBV DNAemia surveillance to identify patients at risk for PTLD and to inform pre-emptive interventions in patients who are EBV seronegative pre-transplant was recommended. In contrast, with the exception of intestinal transplant recipients or those with recent primary EBV infection prior to SOT, surveillance was not recommended in pediatric SOT recipients EBV seropositive pre-transplant. Implications of viral load kinetic parameters including peak load and viral set point on pre-emptive PTLD prevention monitoring algorithms were discussed. Use of additional markers, including measurements of EBV specific cell mediated immunity was discussed but not recommended though the importance of obtaining additional data from prospective multicenter studies was highlighted as a key research priority.
Collapse
Affiliation(s)
- Jutta Preiksaitis
- Division of Infectious Diseases, Department of Medicine, University of Alberta, Edmonton, Alberta, Canada
| | - Upton Allen
- Division of Infectious Diseases and the Transplant and Regenerative Medicine Center, Department of Paediatrics, Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
| | - Catherine M Bollard
- Center for Cancer and Immunology Research, Children's National Hospital, The George Washington University, Washington, District of Columbia, USA
| | - Vikas R Dharnidharka
- Department of Pediatrics, Division of Pediatric Nephrology, Hypertension & Pheresis, Washington University School of Medicine & St. Louis Children's Hospital, St. Louis, Missouri, USA
| | - Daniel E Dulek
- Division of Pediatric Infectious Diseases, Monroe Carell Jr. Children's Hospital at Vanderbilt and Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Michael Green
- Division of Pediatric Infectious Diseases, UPMC Children's Hospital of Pittsburgh, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Olivia M Martinez
- Department of Surgery and Program in Immunology, Stanford University School of Medicine, Stanford, California, USA
| | - Diana M Metes
- Departments of Surgery and Immunology, Thomas E. Starzl Transplantation Institute, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Marian G Michaels
- Division of Pediatric Infectious Diseases, UPMC Children's Hospital of Pittsburgh, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Françoise Smets
- Pediatric Gastroenterology and Hepatology, Cliniques Universitaires Saint-Luc, UCLouvain, Brussels, Belgium
| | | | - Patrizia Comoli
- Cell Factory & Pediatric Hematology/Oncology, Fondazione IRCCS Policlinico, Pavia, Italy
| | - Lara Danziger-Isakov
- Division of Infectious Disease, Department of Pediatrics, Cincinnati Children's Hospital Medical Center, University of Cincinnati, Cincinnati, Ohio, USA
| | - Anne I Dipchand
- Labatt Family Heart Centre, Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
| | | | - Judith A Ferry
- Harvard Medical School, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Thomas G Gross
- Center for Cancer and Blood Diseases, Children's Hospital Colorado, Aurora, Colorado, USA
| | - Robert J Hayashi
- Division of Pediatric Hematology/Oncology, St. Louis Children's Hospital, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Britta Höcker
- University Children's Hospital, Pediatrics I, Heidelberg, Germany
| | - Arnaud G L'Huillier
- Faculty of Medicine, Pediatric Infectious Diseases Unit and Laboratory of Virology, Geneva University Hospitals, Geneva, Switzerland
| | - Stephen D Marks
- Department of Paediatric Nephrology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
- NIHR Great Ormond Street Hospital Biomedical Research Centre, University College London, Great Ormond Street Institute of Child Health, London, UK
| | - George Vincent Mazariegos
- Department of Surgery, Hillman Center for Pediatric Transplantation, UPMC Children's Hospital of Pittsburgh, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - James Squires
- Division of Gastroenterology, Hepatology and Nutrition, UPMC Children's Hospital of Pittsburgh, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Steven H Swerdlow
- Division of Hematopathology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Ralf U Trappe
- Department of Hematology and Oncology, DIAKO Ev. Diakonie-Krankenhaus Bremen, Bremen, Germany
- Department of Internal Medicine II: Hematology and Oncology, University Medical Centre Schleswig-Holstein, Kiel, Germany
| | - Gary Visner
- Division of Pulmonary Medicine, Boston Children's Hospital/Harvard Medical School, Boston, Massachusetts, USA
| | - Steven A Webber
- Department of Pediatrics, Vanderbilt School of Medicine, Nashville, Tennessee, USA
| | - James D Wilkinson
- Department of Pediatrics, Vanderbilt School of Medicine, Nashville, Tennessee, USA
| | | |
Collapse
|
2
|
Dong SW, Blair BM, Alonso CD. Single-Center Outcomes of Epstein-Barr Virus DNAemia in Adult Solid Organ Transplant Recipients. J Transplant 2024; 2024:5598324. [PMID: 38283325 PMCID: PMC10810690 DOI: 10.1155/2024/5598324] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 09/24/2023] [Accepted: 12/12/2023] [Indexed: 01/30/2024] Open
Abstract
Background Immunosuppression in solid organ transplantation (SOT) increases the risk of Epstein-Barr virus (EBV) DNAemia, which may herald development of posttransplant lymphoproliferative disease (PTLD). Few studies have characterized the incidence, risk factors, and clinical impact of EBV DNAemia in adult SOT recipients (SOTR). Methods A single-center, retrospective review of adult (≥18 years) SOTR between 01 January 2015 and 31 December 2019 was conducted. Patients were stratified by the primary study endpoint of development of EBV DNAemia (whole blood EBV DNA PCR > 200 copies/mL). Secondary endpoints included development of PTLD, reduction in immunosuppression (RIS), use of pre-emptive therapy, and all-cause mortality. Results Among 442 adult SOTR, the predominant transplant organs were the kidney (258, 58%) and liver (141, 31.9%). EBV serostatus in most subjects (430, 97%) was classified as intermediate risk (R+). Eight subjects (2%) were high risk (donor (D+/R-), and 4 (1%) were low risk (D-/R-). The overall incidence of EBV DNAemia was 4.1% (18/442) with a median time to detection of 14 months (range 3-60). The highest proportion of DNAemia was observed in D+/R- subjects (37.5%; p < 0.001). Development of PTLD was significantly associated with EBV DNAemia and occurred in 3/18 patients with DNAemia (16.7%) vs. 3/424 (0.7%) without DNAemia (p < 0.001). All patients with PTLD were managed with RIS and rituximab. Conclusion We observed that EBV D+/R- serostatus and development of sustained EBV DNAemia were high risk features associated with subsequent development of PTLD in our cohort of adult SOTR.
Collapse
Affiliation(s)
- Sara W. Dong
- Division of Infectious Disease, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
- Division of Infectious Disease, Department of Pediatrics, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Barbra M. Blair
- Division of Infectious Disease, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Carolyn D. Alonso
- Division of Infectious Disease, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| |
Collapse
|
3
|
Blazquez-Navarro A, Dang-Heine C, Wehler P, Roch T, Bauer C, Neumann S, Blazquez-Navarro R, Kurchenko A, Wolk K, Sabat R, Westhoff TH, Olek S, Thomusch O, Seitz H, Reinke P, Hugo C, Sawitzki B, Or-Guil M, Babel N. Risk factors for Epstein-Barr virus reactivation after renal transplantation: Results of a large, multi-centre study. Transpl Int 2021; 34:1680-1688. [PMID: 34448272 DOI: 10.1111/tri.13982] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 07/15/2021] [Accepted: 07/15/2021] [Indexed: 01/02/2023]
Abstract
Epstein-Barr virus (EBV) reactivation is a very common and potentially lethal complication of renal transplantation. However, its risk factors and effects on transplant outcome are not well known. Here, we have analysed a large, multi-centre cohort (N = 512) in which 18.4% of the patients experienced EBV reactivation during the first post-transplant year. The patients were characterized pre-transplant and two weeks post-transplant by a multi-level biomarker panel. EBV reactivation was episodic for most patients, only 12 patients showed prolonged viraemia for over four months. Pre-transplant EBV shedding and male sex were associated with significantly increased incidence of post-transplant EBV reactivation. Importantly, we also identified a significant association of post-transplant EBV with acute rejection and with decreased haemoglobin levels. No further severe complications associated with EBV, either episodic or chronic, could be detected. Our data suggest that despite relatively frequent EBV reactivation, it had no association with serious complications during the first post-transplantation year. EBV shedding prior to transplantation could be employed as biomarkers for personalized immunosuppressive therapy. In summary, our results support the employed immunosuppressive regimes as relatively safe with regard to EBV. However, long-term studies are paramount to support these conclusions.
Collapse
Affiliation(s)
- Arturo Blazquez-Navarro
- Systems Immunology Lab, Department of Biology, Humboldt-Universität zu Berlin, Berlin, Germany.,Berlin Institute of Health Center for Regenerative Therapies (BCRT): Berlin-Brandenburger Centrum für Regenerative Therapien, Charité - Universitätsmedizin Berlin, Berlin, Germany.,Center for Translational Medicine, Universitätsklinikum der Ruhr-Universität Bochum, Medizinische Klinik I, Herne, Germany
| | - Chantip Dang-Heine
- Clinical Study Center (CSC), Berlin Institute of Health, and Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Patrizia Wehler
- Berlin Institute of Health Center for Regenerative Therapies (BCRT): Berlin-Brandenburger Centrum für Regenerative Therapien, Charité - Universitätsmedizin Berlin, Berlin, Germany.,Center for Translational Medicine, Universitätsklinikum der Ruhr-Universität Bochum, Medizinische Klinik I, Herne, Germany
| | - Toralf Roch
- Berlin Institute of Health Center for Regenerative Therapies (BCRT): Berlin-Brandenburger Centrum für Regenerative Therapien, Charité - Universitätsmedizin Berlin, Berlin, Germany.,Center for Translational Medicine, Universitätsklinikum der Ruhr-Universität Bochum, Medizinische Klinik I, Herne, Germany
| | | | | | | | - Andriy Kurchenko
- Department of Clinical Immunology and Allergology, Bogolomets National Medical University, Kiev, Ukraine
| | - Kerstin Wolk
- Berlin Institute of Health Center for Regenerative Therapies (BCRT): Berlin-Brandenburger Centrum für Regenerative Therapien, Charité - Universitätsmedizin Berlin, Berlin, Germany.,Psoriasis Research and Treatment Center, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Robert Sabat
- Berlin Institute of Health Center for Regenerative Therapies (BCRT): Berlin-Brandenburger Centrum für Regenerative Therapien, Charité - Universitätsmedizin Berlin, Berlin, Germany.,Psoriasis Research and Treatment Center, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Timm H Westhoff
- Center for Translational Medicine, Universitätsklinikum der Ruhr-Universität Bochum, Medizinische Klinik I, Herne, Germany
| | - Sven Olek
- Ivana Türbachova Laboratory for Epigenetics, Epiontis GmbH, Precision for Medicine Group, Berlin, Germany
| | - Oliver Thomusch
- Klinik für Allgemein- und Viszeralchirurgie, Universitätsklinikum Freiburg, Freiburg, Germany
| | - Harald Seitz
- Fraunhofer Institute for Cell Therapy and Immunology, Branch Bioanalytics und Bioprocesses, Leipzig, Germany
| | - Petra Reinke
- Berlin Institute of Health Center for Regenerative Therapies (BCRT): Berlin-Brandenburger Centrum für Regenerative Therapien, Charité - Universitätsmedizin Berlin, Berlin, Germany.,Berlin Center for Advanced Therapies (BeCAT), Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Christian Hugo
- Universitätsklinikum Carl Gustav Carus, Medizinische Klinik III - Bereich Nephrologie, Dresden, Germany
| | - Birgit Sawitzki
- Berlin Institute of Health Center for Regenerative Therapies (BCRT): Berlin-Brandenburger Centrum für Regenerative Therapien, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Michal Or-Guil
- Systems Immunology Lab, Department of Biology, Humboldt-Universität zu Berlin, Berlin, Germany.,Institute of Medical Immunology, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Nina Babel
- Berlin Institute of Health Center for Regenerative Therapies (BCRT): Berlin-Brandenburger Centrum für Regenerative Therapien, Charité - Universitätsmedizin Berlin, Berlin, Germany.,Center for Translational Medicine, Universitätsklinikum der Ruhr-Universität Bochum, Medizinische Klinik I, Herne, Germany
| |
Collapse
|
4
|
In vitro comparison of currently available and investigational antiviral agents against pathogenic human double-stranded DNA viruses: A systematic literature review. Antiviral Res 2019; 163:50-58. [PMID: 30677427 DOI: 10.1016/j.antiviral.2019.01.008] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Revised: 01/10/2019] [Accepted: 01/16/2019] [Indexed: 12/14/2022]
Abstract
BACKGROUND Double-stranded (ds) DNA virus infections often occur concomitantly in immunocompromised patients. We performed a systematic search of published in vitro activity for nine approved and investigational antivirals to understand the spectrum of in vitro activity against dsDNA viruses. METHODS A literature search was performed (PubMed and the WoS Core Collection) using keywords related to: 1) targeted approved/developmental antivirals (acyclovir, artesunate, brincidofovir, cidofovir, cyclopropavir (filociclovir), foscarnet, ganciclovir, letermovir, and maribavir); 2) pathogenic dsDNA viruses; 3) in vitro activity. We summarized data from 210 publications. RESULTS Activity against ≤3 viruses was documented for maribavir (cytomegalovirus, Epstein-Barr virus), and letermovir, while activity against > 3 viruses was shown for ganciclovir, cidofovir, acyclovir, foscarnet, cyclopropavir, artesunate, and brincidofovir. The EC50 values of brincidofovir were the lowest, ranging from 0.001 to 0.27 μM, for all viruses except papillomaviruses. The next most potent agents included cidofovir, ganciclovir, foscarnet, and acyclovir with EC50 values between 0.1 μM and >10 μM for cytomegalovirus, herpes simplex virus, and adenovirus. CONCLUSION Most of the identified antivirals had in vitro activity against more than one dsDNA virus. Brincidofovir and cidofovir have broad-spectrum activity, and brincidofovir has the lowest EC50 values. These findings could assist clinical practice and developmental research.
Collapse
|
5
|
Dendle C, Mulley WR, Holdsworth S. Can immune biomarkers predict infections in solid organ transplant recipients? A review of current evidence. Transplant Rev (Orlando) 2018; 33:87-98. [PMID: 30551846 DOI: 10.1016/j.trre.2018.10.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2018] [Revised: 10/01/2018] [Accepted: 10/02/2018] [Indexed: 12/12/2022]
Abstract
Despite improvements in graft survival, solid organ transplantation is still associated with considerable infection induced morbidity and mortality. If we were able to show that serious infection risk was associated with excessive suppression of immune capacity, we would be justified in "personalizing" the extent of immunosuppression by carefully monitored reduction to see if we can improve immune compromize without increasing the risk of rejection. Reliable biomarkers are needed to identify this patients at an increased risk of infection. This review focuses on the currently available evidence in solid organ transplant recipients for immune non-pathogen specific biomarkers to predict severe infections with the susceptibility to particular pathogens according to the component of the immune system that is suppressed. This review is categorized into immune biomarkers representative of the humoral, cellular, phagocytic, natural killer cell and complement system. Biomarkers humoral and cellular systems of the that have demonstrated an association with infections include immunoglobulins, lymphocyte number, lymphocyte subsets, intracellular concentrations of adenosine triphosphate in stimulated CD4+ cells and soluble CD30. Biomarkers of the innate immune system that have demonstrated an association with infections include natural killer cell numbers, complement and mannose binding lectin. Emerging evidence shows that quantification of viral nucleic acid (such as Epstein Barr Virus) can act as a biomarker to predict all-cause infections. Studies that show the most promise are those in which several immune biomarkers are assessed in combination. Ongoing research is required to validate non-pathogen specific immune biomarkers in multi-centre studies using standardized study designs.
Collapse
Affiliation(s)
- Claire Dendle
- Centre for Inflammatory Diseases, School of Clinical Sciences, Monash University and Monash Infectious Diseases, Monash Health, Australia.
| | - William R Mulley
- Centre for Inflammatory Diseases, School of Clinical Sciences, Monash University, Australia; Department of Nephrology, Monash Medical Centre, Clayton, Victoria 3168, Australia.
| | - Stephen Holdsworth
- Centre for Inflammatory Diseases, School of Clinical Sciences, Monash University, Australia; Department of Nephrology, Monash Medical Centre, Clayton, Victoria 3168, Australia.
| |
Collapse
|
6
|
Le J, Durand CM, Agha I, Brennan DC. Epstein-Barr virus and renal transplantation. Transplant Rev (Orlando) 2016; 31:55-60. [PMID: 28089555 DOI: 10.1016/j.trre.2016.12.001] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Revised: 12/12/2016] [Accepted: 12/25/2016] [Indexed: 01/22/2023]
Abstract
Epstein-Barr virus (EBV) is a gamma herpesvirus associated with diseases ranging from asymptomatic viremia to post-transplant malignancies in kidney transplant recipients. EBV specifically is associated with post-transplantation lymphoproliferative disorder (PTLD), in kidney transplant recipients, with increased risk in EBV seronegative patients with EBV seropositive donors on intensified immunosuppression. The diagnosis of PTLD relies on clinical suspicion plus tissue biopsy with polymerase chain reaction (PCR) testing of blood currently used for risk determination in high-risk recipients. Therapeutic strategies for PTLD include reduction of immunosuppression, chemotherapy and rituximab, and consideration of sirolimus-based immunosuppression. Antivirals such as ganciclovir are used to prevent reactivation of cytomegalovirus and other herpes viruses but are not onco-therapeutic. Radiation therapy or surgery is indicated for bulky, disseminated or recalcitrant disease. Prognosis varies depending on the type of malignancy identified and stage of disease.
Collapse
Affiliation(s)
- Jade Le
- University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75390, United States
| | - Christine M Durand
- Johns Hopkins Medical Institute, 1830 East Monument Street, Room 450D, Baltimore, MD 21287, United States
| | - Irfan Agha
- Dallas Renal Group, 3571 W. Wheatland Road, Suite 101, Dallas, TX 75237, United States
| | - Daniel C Brennan
- Washington University School of Medicine, 660 S Euclid Ave, St. Louis, MO 63110, United States.
| |
Collapse
|
7
|
The clinical significance of EBV DNA in the plasma and peripheral blood mononuclear cells of patients with or without EBV diseases. Blood 2016; 127:2007-17. [PMID: 26744460 DOI: 10.1182/blood-2015-09-672030] [Citation(s) in RCA: 147] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Accepted: 01/04/2016] [Indexed: 01/05/2023] Open
Abstract
Epstein-Barr virus (EBV) is a ubiquitous virus that establishes a latent infection within the host and in some cases can lead to the development of EBV-associated lymphomas, lymphoproliferative disorders, hemophagocytic lymphohistiocytosis, solid tumors, and other diseases. We studied the clinical significance of detecting EBV DNA in the plasma and peripheral blood mononuclear cells (PBMCs) of 2146 patients who had blood specimens sent to the Johns Hopkins Hospital clinical laboratory for viral quantitative real-time polymerase chain reaction assay over a 5-year period. Within this largely immunocompromised and hospitalized cohort, 535 patients (25%) had EBV detected in plasma or PBMCs. When EBV was detected in the absence of an EBV(+)disease (n = 402), it was present only in PBMCs in 69% of cases. Immunocompromised patients were less likely to have EBV in plasma than in PBMCs in the absence of EBV(+)disease. In patients with active, systemic EBV(+)diseases (n = 105), EBV was detected in plasma in 99% of cases but detected in PBMCs in only 54%. Across a range of copy number cutoffs, EBV in plasma had higher specificity and sensitivity for EBV(+)disease as compared with EBV in PBMCs. EBV copy number in plasma distinguished untreated, EBV(+)lymphoma from EBV(+)lymphoma in remission and EBV(-)lymphoma, and also distinguished untreated, EBV(+)posttransplantation lymphoproliferative disorder (PTLD) from EBV(+)PTLD in remission and EBV(-)PTLD. EBV copy number quantification is a useful diagnostic marker across the spectrum of EBV(+)diseases, even among immunocompromised patients, with plasma specimens more indicative of EBV(+)disease than PBMCs.
Collapse
|
8
|
Lam GY, Halloran BP, Peters AC, Fedorak RN. Lymphoproliferative disorders in inflammatory bowel disease patients on immunosuppression: Lessons from other inflammatory disorders. World J Gastrointest Pathophysiol 2015; 6:181-192. [PMID: 26600976 PMCID: PMC4644882 DOI: 10.4291/wjgp.v6.i4.181] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Accepted: 09/28/2015] [Indexed: 02/06/2023] Open
Abstract
Immunosuppressive agents, such as thiopurines, methotrexate, and biologics, have revolutionized the treatment of inflammatory bowel disease (IBD). However, a number of case reports, case control studies and retrospective studies over the last decade have identified a concerning link between immunosuppression and lymphoproliferative disorders (LPDs), the oncological phenomenon whereby lymphocytes divide uncontrollably. These LPDs have been associated with Epstein-Barr virus (EBV) infection in which the virus provides the impetus for malignant transformation while immunosuppression hampers the immune system’s ability to detect and clear these malignant cells. As such, the use of immunosuppressive agents may come at the cost of increased risk of developing LPD. While little is known about the LPD risk in IBD, more is known about immunosuppression in the post-transplantation setting and the development of EBV associated post-transplantation lymphoproliferative disorders (PTLD). In review of the PTLD literature, evidence is available to demonstrate that certain immune suppressants such as cyclosporine and T-lymphocyte modulators in particular are associated with an increased risk of PTLD development. As well, high doses of immunosuppressive agents and multiple immunosuppressive agent use are also linked to increased PTLD development. Here, we discuss these findings in context of IBD and what future studies can be taken to understand and reduce the risk of EBV-associated LPD development from immunosuppression use in IBD.
Collapse
|
9
|
Yamada N, Sanada Y, Okada N, Wakiya T, Ihara Y, Urahashi T, Mizuta K. Successful rescue of disseminated varicella infection with multiple organ failure in a pediatric living donor liver transplant recipient: a case report and literature review. Virol J 2015; 12:91. [PMID: 26081644 PMCID: PMC4480512 DOI: 10.1186/s12985-015-0311-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2015] [Accepted: 05/15/2015] [Indexed: 12/28/2022] Open
Abstract
A 12-year-old female patient with biliary atresia underwent living donor liver transplantation (LDLT). Twelve months after the LDLT, she developed acute hepatitis (alanine aminotransferase 584 IU/L) and was diagnosed with disseminated varicella-zoster virus (VZV) infection with high level of serum VZV-DNA (1.5 × 105 copies/mL) and generalized vesicular rash. She had received the VZV vaccination when she was 5-years-old and had not been exposed to chicken pox before the LDLT, and her serum was positive for VZV immunoglobulin G at the time of the LDLT. Although she underwent treatment with intravenous acyclovir, intravenous immunoglobulin, and withdrawal of immunosuppressants, her symptoms worsened and were accompanied by disseminated intravascular coagulation, pneumonia, and encephalitis. These complications required treatment in the intensive care unit for 16 days. Five weeks later, her clinical findings improved, although her VZV-DNA levels remained high (8.5 × 103copies/mL). Oral acyclovir was added for 2 weeks, and she was eventually discharged from our hospital on day 86 after admission; she has not experienced a recurrence. In conclusion, although disseminated VZV infection with multiple organ failure after pediatric LDLT is a life-threatening disease, it can be cured via an early diagnosis and intensive treatment.
Collapse
Affiliation(s)
- Naoya Yamada
- Department of Transplant Surgery, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke-shi, Tochigi, 329-0498, Japan.
| | - Yukihiro Sanada
- Department of Transplant Surgery, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke-shi, Tochigi, 329-0498, Japan.
| | - Noriki Okada
- Department of Transplant Surgery, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke-shi, Tochigi, 329-0498, Japan.
| | - Taiichi Wakiya
- Department of Transplant Surgery, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke-shi, Tochigi, 329-0498, Japan.
| | - Yoshiyuki Ihara
- Department of Transplant Surgery, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke-shi, Tochigi, 329-0498, Japan.
| | - Taizen Urahashi
- Department of Transplant Surgery, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke-shi, Tochigi, 329-0498, Japan.
| | - Koichi Mizuta
- Department of Transplant Surgery, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke-shi, Tochigi, 329-0498, Japan.
| |
Collapse
|
10
|
Jamalidoust M, Geramizadeh B, Pouladfar G, Namayandeh M, Asaie S, Aliabadi N, Nikeghbalian S, Ziyaeyan M. Epstein-Barr virus DNAemia in Iranian liver transplant recipients and assessment of its variation in posttransplant lymphproliferative disorder patients by quantitative polymerase chain reaction assay. EXP CLIN TRANSPLANT 2015; 13 Suppl 1:306-11. [PMID: 25894179 DOI: 10.6002/ect.mesot2014.p148] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
OBJECTIVES Epstein-Barr virus primary infection and/or reactivation may play a major role in the incidence of posttransplant lymphoproliferative disorder in organ recipients. We assessed Epstein-Barr virus viral load in liver transplant patients suspected of having Epstein-Barr virus/ posttransplant lymphoproliferative disorder at specified times after transplant and evaluated the clinical findings and posttransplant complications. MATERIALS AND METHODS In the 696 patients who underwent liver transplant in this retrospective study, Epstein-Barr virus viral load was examined intermittently in 127 liver transplant recipients who were suspected to have Epstein-Barr virus infection/disease. Sampling was performed during 4 years from July 2009 to May 2013 using real-time polymerase chain reaction assay. Clinical and pathologic data were gathered by reviewing medical records. RESULTS There were 78 of the 127 suspected patients (61%) who exhibited Epstein-Barr virus DNAemia and 19 patients had posttransplant lymphoproliferative disorder. The median EBV viral load of posttransplant lymphoproliferative disorder patients was significantly higher than unaffected patients. Posttransplant lymphoproliferative disorder was diagnosed clinically in 34 subjects (4.9%). Estimated mortality rate of posttransplant lymphoproliferative disorder patients was 35% during 1.5-year follow-up after transplant. CONCLUSIONS Monitoring Epstein-Barr virus load may enable detection of Epstein-Barr virus infection/disease in liver transplant patients suspected of having the virus, even several weeks before the onset of any clinical manifestations, especially in pediatric patients who have high incidence and mortality from posttransplant lymphoproliferative disorder.
Collapse
Affiliation(s)
- Marzieh Jamalidoust
- From the Professor Alborzi Clinical Microbiology Research Center, Shiraz University of Medical Sciences, Nemazee Hospital, Shiraz; and the Department of Virology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | | | | | | | | | | | | | | |
Collapse
|
11
|
Kanakry J, Ambinder R. The Biology and Clinical Utility of EBV Monitoring in Blood. Curr Top Microbiol Immunol 2015; 391:475-99. [PMID: 26428386 DOI: 10.1007/978-3-319-22834-1_17] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Epstein-Barr virus (EBV) DNA in blood can be quantified in peripheral blood mononuclear cells, in circulating cell-free (CCF) DNA specimens, or in whole blood. CCF viral DNA may be actively released or extruded from viable cells, packaged in virions or passively shed from cells during apoptosis or necrosis. In infectious mononucleosis, viral DNA is detected in each of these kinds of specimens, although it is only transiently detected in CCF specimens. In nasopharyngeal carcinoma, CCF EBV DNA is an established tumor marker. In EBV-associated Hodgkin lymphoma and in EBV-associated extranodal NK-/T-cell lymphoma, there is growing evidence for the utility of CCF DNA as a tumor marker.
Collapse
Affiliation(s)
- Jennifer Kanakry
- Department of Oncology, Johns Hopkins School of Medicine, 389 CRB1 1650 Orleans, Baltimore, MD, 21287, USA
| | - Richard Ambinder
- Department of Oncology, Johns Hopkins School of Medicine, 389 CRB1 1650 Orleans, Baltimore, MD, 21287, USA.
| |
Collapse
|
12
|
Halliday N, Smith C, Atkinson C, O'Beirne J, Patch D, Burroughs AK, Thorburn D, Haque T. Characteristics of Epstein-Barr viraemia in adult liver transplant patients: A retrospective cohort study. Transpl Int 2014; 27:838-46. [DOI: 10.1111/tri.12342] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2013] [Revised: 11/25/2013] [Accepted: 04/14/2014] [Indexed: 11/27/2022]
Affiliation(s)
- Neil Halliday
- Department of Virology; Royal Free London NHS Foundation Trust; London UK
| | - Colette Smith
- Research Department of Infection and Population Health; UCL; London UK
| | - Claire Atkinson
- Department of Virology; Royal Free London NHS Foundation Trust; London UK
| | - James O'Beirne
- Institute of Liver and Digestive Health; Royal Free London NHS Foundation Trust; London UK
| | - David Patch
- Institute of Liver and Digestive Health; Royal Free London NHS Foundation Trust; London UK
| | - Andrew K Burroughs
- Institute of Liver and Digestive Health; Royal Free London NHS Foundation Trust; London UK
| | - Douglas Thorburn
- Institute of Liver and Digestive Health; Royal Free London NHS Foundation Trust; London UK
| | - Tanzina Haque
- Department of Virology; Royal Free London NHS Foundation Trust; London UK
| |
Collapse
|
13
|
Holman CJ, Karger AB, Mullan BD, Brundage RC, Balfour HH. Quantitative Epstein-Barr virus shedding and its correlation with the risk of post-transplant lymphoproliferative disorder. Clin Transplant 2012; 26:741-7. [PMID: 22385033 DOI: 10.1111/j.1399-0012.2012.01608.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/29/2011] [Indexed: 12/11/2022]
Abstract
We postulated that quantitative monitoring of Epstein-Barr virus (EBV) shedding after transplantation could distinguish EBV-associated illnesses and predict clinical outcome. EBV DNA was measured in solid organ (SOT) and hematopoietic cell transplants (HCT) using our own real-time TaqMan EBV PCR. The proportion of patients who had EBV DNAemia post-transplant was significantly lower in HCT vs. SOT (p < 0.001). Over a 7.5-yr period, post-transplant lymphoproliferative disorder (PTLD) occurred in 66 (5.8%) of 1131 patients who met adequate monitoring criteria. SOT recipients developed PTLD significantly later than HCT recipients (median, 2.8 yr vs. 121 d; p < 0.001). PTLD was documented in 53 (14%) of 376 patients who had EBV in ≥1 whole blood sample vs. 13 (2%) of 755 patients who had at least three EBV-negative blood samples and were never positive. PTLD risk in viremic patients increased with the peak quantity of EBV DNAemia (p < 0.001). PTLD occurred in 37/333 (11%) of patients with peak blood levels 10(3) -10(5) copies/mL vs. 16/43 (37%) of patients with levels >10(5) (p < 0.001). EBV PCR was predictive in 29 (78%) of 37 patients tested within three wk prior to tissue diagnosis of PTLD, and thus, we conclude that EBV PCR with careful attention paid to changes in EBV DNAemia could lead to earlier diagnosis and treatment of PTLD.
Collapse
Affiliation(s)
- Carol J Holman
- Department of Laboratory Medicine and Pathology, University of Minnesota Medical Center, Minneapolis, MN 55455, USA
| | | | | | | | | |
Collapse
|
14
|
Schaffer K, Hassan J, Staines A, Coughlan S, Holder P, Tuite G, McCormick AP, Traynor O, Hall WW, Connell J. Surveillance of Epstein-Barr virus loads in adult liver transplantation: associations with age, sex, posttransplant times, and transplant indications. Liver Transpl 2011; 17:1420-6. [PMID: 21837744 DOI: 10.1002/lt.22406] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Epstein-Barr virus (EBV)-associated posttransplant lymphoproliferative disorder (PTLD) is a life-threatening complication after adult orthotopic liver transplantation (AOLT). Besides EBV and immunosuppression, relatively little is known about the pretransplant clinical parameters associated with the risk of PTLD, and the benefit of using EBV surveillance to predict EBV-associated disease in AOLT patients is uncertain. The aims of this single-center study were to monitor EBV viral loads (VLs) in AOLT patients and to investigate any associations with age, sex, cytomegalovirus (CMV) serostatus, posttransplant times, and indications for transplantation. 1275 blood samples that were collected from 197 AOLT patients 1 day to more than 15 years after transplantation were investigated with quantitative polymerase chain reaction for EBV and CMV DNA. Seventy-two percent of the patients had EBV DNAemia less than 100 days after transplantation without clinical manifestations. No association was observed between the EBV copy numbers and the time since transplantation. EBV DNAemia was weakly associated with male sex but was not associated with age, CMV serostatus, or indications for AOLT. The highest EBV VL levels were observed in patients who presented with congenital liver diseases, whereas patients with viral hepatitis maintained high EBV VLs after transplantation. None of the patients developed PTLD during the study period; however, 3 patients presented with EBV-associated diseases. In conclusion, EBV DNAemia is common in AOLT patients, and routine EBV surveillance has limited value for predicting EBV-associated morbidity or mortality.
Collapse
Affiliation(s)
- Kirsten Schaffer
- Department of Microbiology, St. Vincent's University Hospital, Dublin, Ireland.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
15
|
|
16
|
Lay MLJ, Lucas RM, Ratnamohan M, Taylor J, Ponsonby AL, Dwyer DE. Measurement of Epstein-Barr virus DNA load using a novel quantification standard containing two EBV DNA targets and SYBR Green I dye. Virol J 2010; 7:252. [PMID: 20860842 PMCID: PMC2958162 DOI: 10.1186/1743-422x-7-252] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2010] [Accepted: 09/22/2010] [Indexed: 12/15/2022] Open
Abstract
Background Reactivation of Epstein-Barr virus (EBV) infection may cause serious, life-threatening complications in immunocompromised individuals. EBV DNA is often detected in EBV-associated disease states, with viral load believed to be a reflection of virus activity. Two separate real-time quantitative polymerase chain reaction (QPCR) assays using SYBR Green I dye and a single quantification standard containing two EBV genes, Epstein-Barr nuclear antigen-1 (EBNA-1) and BamHI fragment H rightward open reading frame-1 (BHRF-1), were developed to detect and measure absolute EBV DNA load in patients with various EBV-associated diseases. EBV DNA loads and viral capsid antigen (VCA) IgG antibody titres were also quantified on a population sample. Results EBV DNA was measurable in ethylenediaminetetraacetic acid (EDTA) whole blood, peripheral blood mononuclear cells (PBMCs), plasma and cerebrospinal fluid (CSF) samples. EBV DNA loads were detectable from 8.0 × 102 to 1.3 × 108 copies/ml in post-transplant lymphoproliferative disease (n = 5), 1.5 × 103 to 2.0 × 105 copies/ml in infectious mononucleosis (n = 7), 7.5 × 104 to 1.1 × 105 copies/ml in EBV-associated haemophagocytic syndrome (n = 1), 2.0 × 102 to 5.6 × 103 copies/ml in HIV-infected patients (n = 12), and 2.0 × 102 to 9.1 × 104 copies/ml in the population sample (n = 218). EBNA-1 and BHRF-1 DNA were detected in 11.0% and 21.6% of the population sample respectively. There was a modest correlation between VCA IgG antibody titre and BHRF-1 DNA load (rho = 0.13, p = 0.05) but not EBNA-1 DNA load (rho = 0.11, p = 0.11). Conclusion Two sensitive and specific real-time PCR assays using SYBR Green I dye and a single quantification standard containing two EBV DNA targets, were developed for the detection and measurement of EBV DNA load in a variety of clinical samples. These assays have application in the investigation of EBV-related illnesses in immunocompromised individuals.
Collapse
Affiliation(s)
- Meav-Lang J Lay
- Virology Department, Centre For Infectious Diseases & Microbiology Laboratory Services, Institute of Clinical Pathology & Medical Research, Institute Road, Westmead Hospital, Westmead 2145, New South Wales, Australia.
| | | | | | | | | | | | | |
Collapse
|
17
|
LOGINOV RAISA, HALME LEENA, AROLA JOHANNA, HÖCKERSTEDT KRISTER, LAUTENSCHLAGER IRMELI. Intragraft immunological events associated with EBV DNAemia in liver transplant patients. APMIS 2010; 118:888-94. [DOI: 10.1111/j.1600-0463.2010.02675.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
18
|
Cavallo R, Elia M, Gruosso V, Curtoni A, Costa C, Bergallo M. Molecular Epidemiology of Epstein-Barr Virus in Adult Kidney Transplant Recipients. Transplant Proc 2010; 42:2527-30. [DOI: 10.1016/j.transproceed.2010.05.151] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2009] [Revised: 12/31/2009] [Accepted: 05/03/2010] [Indexed: 12/12/2022]
|
19
|
Epidemiology of pretransplant EBV and CMV serostatus in relation to posttransplant non-Hodgkin lymphoma. Transplantation 2010; 88:962-7. [PMID: 19855238 DOI: 10.1097/tp.0b013e3181b9692d] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
BACKGROUND.: Despite the importance of non-Hodgkin lymphoma (NHL) as a posttransplant complication, the relationship between NHL and recipient seropositivity for Epstein-Barr virus (EBV) or cytomegalovirus (CMV) is incompletely understood. METHODS.: Kidney, heart, and liver transplant recipients reported to the Collaborative Transplant Study with known pretransplant EBV and CMV serostatus were analyzed in terms of clinically manifest NHL. Cox multivariate regression analysis was performed to account for a wide range of possible confounders. RESULTS.: In total, 18,682 kidney, 2042 heart, and 2616 liver transplant recipients were analyzed. Regardless of age, pretransplant EBV serostatus was significantly associated with risk of NHL in kidney transplant recipients (P<0.001). There was no significant difference in lymphoma rates according to CMV and CMV serostatus among EBV and EBV recipients (log-rank P=0.55 and P=0.57, respectively), but hospitalization for CMV disease during year 1 posttransplant was associated with subsequent NHL (hazard ratio [HR] 6.1; 95% confidence interval [CI] 2.0-18.4; P=0.001). EBV serostatus was also associated with increased risk of NHL in heart transplant patients (HR 3.6; 95% CI 1.1-11.3; P=0.031) but, contrary to expectation, not in liver recipients (HR 0.6; 95% CI 0.1-1.7; P=0.32). CONCLUSIONS.: In view of the striking increase in risk of NHL in EBV kidney transplant recipients of all ages, EBV serostatus should be determined pretransplant in all age groups. CMV serostatus was not independently associated with risk of NHL after kidney transplantation. Surprisingly, in liver transplantation, the risk of NHL was virtually unaffected by EBV serostatus.
Collapse
|
20
|
Martelius T, Lappalainen M, Aalto SM, Nihtinen A, Hedman K, Anttila VJ. Clinical characteristics, outcome and the role of viral load in nontransplant patients with Epstein-Barr viraemia. Clin Microbiol Infect 2009; 16:657-62. [PMID: 19694766 DOI: 10.1111/j.1469-0691.2009.02922.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Epstein-Barr virus (EBV) is important in the development of post-transplant lymphoproliferative disease in allogeneic stem cell and solid organ transplant recipients. We have studied the clinical significance of EBV DNAaemia among nontransplant patients in a tertiary referral hospital. We retrospectively reviewed the medical records for main diagnosis, outcome, immunosuppressive/cytotoxic chemotherapy and other opportunistic infections of the patients who were found positive in quantitative real-time PCR assay for EBV (EBV-qPCR) between the years 2000 and 2007. Allogeneic stem cell and solid organ transplant recipients were excluded, and all patients in nonsurgical adult wards were included. Altogether, 62 patients had at least one plasma sample positive with an EBV-qPCR. Fifteen were immunocompetent, most had primary EBV infection, and the outcome was good. On the other hand, 36 had malignant disease, seven had HIV infection and seven had immunosuppressive conditions of an other aetiology. All but one of the malignancies were of lymphoid origin, and most of these patients had a history of multiple cytotoxic treatments. Immunosuppressed patients had higher viral loads. EBV viraemia is associated with severe immunosuppression and lymphoid malignancies.
Collapse
Affiliation(s)
- T Martelius
- Department of Medicine, Divisions of Infectious Diseases, University of Helsinki and Helsinki University Central Hospital, Helsinki, Finland.
| | | | | | | | | | | |
Collapse
|
21
|
Prospective Monitoring of Epstein-Barr Virus DNA in Adult Renal Transplant Recipients During the Early Posttransplant Period: Role of Mycophenolate Mofetil. Transplantation 2009; 87:852-6. [DOI: 10.1097/tp.0b013e318199f983] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
22
|
Comparison of two highly automated DNA extraction systems for quantifying Epstein–Barr virus in whole blood. J Clin Virol 2008; 43:272-6. [DOI: 10.1016/j.jcv.2008.08.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2008] [Revised: 08/06/2008] [Accepted: 08/11/2008] [Indexed: 11/19/2022]
|