Epstein-Barr Virus Paul Auwaerter, M.D MICROBIOLOGY • • Epstein-Barr virus, a gamma herpes virus also known as human herpesvirus (HHV-4) Establishes life-long latent infection CLINICAL Subclinical infection typical (90%), especially in children • o o o • Infection is more prevalent and occurs at an earlier age in lower socioeconomic groups EBV mostly spread by asymptomatic salivary shedding In the developed world, 95% eventually infected by age 40, an estimated 30-40% college freshman are uninfected Primary symptomatic infection = infectious mononucleosis (IM) IM peaks in teens and early 20s, with 30-77% of adolescents/adults experiencing symptoms with primary infection Ddx mononucleosis syndrome: includes Group A Streptococcal pharyngitis, acute CMV, acute HIV, toxoplasmosis, influenza, viral hepatitis, rubella, drug reactions Laboratory hallmarks of primary infection, clinically symptomatic: o • • Elevated WBC (10-18K) typical with lymphocytosis (40->60%) common o Atypical lymphocytes [Fig] usually comprise 10-30+% of circulating lymphocytes Dx: predominant method is by detection of either non-specific heterophile antibodies or specific EBV serology o • o Heterophile antibody (+) 90% [Monospot™], negatives may turn (+) on repeat 5-10d later Assay predominantly used in the U.S.; advantages inexpensive and rapid o Approximately 10% of primary EBV infection/IM remain heterophile-negative False (+) heterophile rare: lymphoma, hepatitis, SLE, HIV If still suspect IM, order EBV-specific serology: EBV capsid IgM and IgG (+) with negative EBNA diagnostic of acute infection if performed < 4-6 wks from the onset of symptoms This test may be ordered instead of Monospot; often the test of choice in many European countries Positive EBNA in patients suspected of IM (< 4-6wks sx) argues that capsid IgM/IgG titers indicate remote infection therefore NOT supportive of EBV as the cause of mono-like syndrome Occasional low levels may be seen earlier in authentic acute infection o EBV PCR: most helpful for diagnosis of EBV-driven lymphoma, especially for CNS lymphoma in HIV (+) pts Sensitivity reported as high as 97%, specificity 98% but maybe less Also useful with EBV-related meningoencephalitis Do not check EBV titers merely as an evaluation of fatigue EBV is not an explanation as currently understood, for chronic fatigue syndrome o SITES OF INFECTION • Classic triad infectious mononucleosis: fever, pharyngitis, lymphadenopathy (especially posterior cervical) o Common: Elevated LFTs (ALT usually < 300) Splenomegaly (50%) Hepatomegaly Rash (10%), rash following amoxicillin administration occurs >98-100% with IM Uncommon: hemolytic anemia, cytopenias, pneumonitis, carditis, seizures, palsies, Guillain-Barré, encephalitis (late) Abdominal pain: if present in a patient with proven or suspected IM should be considered to have a splenic rupture until proven otherwise o Pts > 35yrs with IM have atypical presentations with less pharyngitis, lymphadenopathy These older patients instead present with more of a primary hepatitis picture, FUO or uncommon complications Life-threatening IM complications: tonsillar airway obstruction (early), splenic rupture (may be spontaneous, typically 1-2 wks post initial sx), encephalitis (typically >1mo after the onset of sx) The severity of IM appears to correlate with the intensity of EBV viral load as well as CD8+cytotoxic T cell response Other processes related to EBV (not necessarily primary infection): o o o • o o o o o HEENT: Oral hairy leukoplakia (HIV) Nasopharyngeal carcinoma HEME: a cause of Burkitt’s lymphoma, implicated in other lymphomas, especially HIV-related, post-transplant lymphoproliferative disorder EBV not an acknowledged cause of Chronic Fatigue Syndrome, but fatigue is common following infectious mononucleosis Chronic active EBV (CAEBV, rare): pancytopenia, chronic LN, pneumonitis, abnormal LFTs > 8wks Prove by repeated positive high plasma or whole blood EBV blood PCR studies and consistent clinical picture This is not "chronic EBV" that is sometimes used as a term for Chronic Fatigue Syndrome An infiltrative disorder that requires hematopoietic stem cell transplantation (HSCT) for a cure Hemophagocytic lymphohistiocytosis (HLH): EBV among the causes of non-genetic acquired HLH, a hyperinflammatory syndrome Frequency appears to be more common in Asian populations Early recognition and treatment important otherwise high mortality Suspect in a severely ill patient, infectious mononucleosis that doesn’t improve after 3-4 weeks with ongoing fever, progressive cytopenias and LFT abnormalities HLH should be considered if fever, cytopenias, elevated LFTs, hepatosplenomegaly, coagulopathy and may develop usually subacutely without IM initial diagnosis Diagnosis based on clinical criteria, one set of criteria proposed by Henter 2007, needing at least of (see: Table Clinical Criteria) Treatment: dexamethasone and etoposide are temporizing, HSCT often required cure Fever ≥38.5°C Splenomegaly Cytopenias (affecting at least lineages) Hemoglobin < 9 g/dL (in infants < 4 weeks: hemoglobin < 10 g/dL) Platelets < 100 × 103/mL Neutrophils < 1 × 103/mL Hypertriglyceridemia (fasting, >265 mg/dL) and/or hypofibrinogenemia (< 150 mg/dL Hemophagocytosis in bone marrow, spleen, lymph nodes, liver, or other tissue Low or absent NK cell activity Ferritin >500 ng/mL Elevated sCD25 (soluble IL-2 receptor): >2,400 U/mL or elevated based on the labora • o o o o Clinical Criteria Post-treatment lymphoproliferative disorder (PTLD): Complication of both solid organ transplantation (SOT) and allogeneic HSCT It is one of the most common posttransplant malignancies, some driven by EBV but others are of unknown cause Risk greatest early after transplantation, usually when immunosuppressive regimens are most intense EBV-negative PTLD tends to occur later, months to years after transplantation The risk for developing PTLD ally painless lymphadenopathy Four classification types: Early lesions: often responding to a reduction in immunosuppression Polymorphic PTLD: a mixture of lymphoid cell types Monomorphic PTLD: due to one cell type, and most common form of PTLD usually causing non-Hodgkin B-cell lymphoma but other types may occur Of the B-types, diffuse large B-cell lymphoma is most common though Burkitt’s seen as well as more rarely other types Classical Hodgkin’s lymphoma: rare Treatment: depending on the type and underlying issues usually decided upon working with transplant physician and oncologist Standard options range from immunosuppressive drug reduction, rituximab, chemotherapy or radiotherapy TREATMENT Infectious Mononucleosis • IM is usually self-limited < 3wks average, with rest and supportive care Little high-quality evidence to back recommendations • Athletes with IM: no training, sports x wks from the onset; if contact sport e.g., football, no sports x wks from the onset and no splenomegaly (document by imaging such as ultrasound if wish to participate < wks) o Counsel patients to avoid traumatic activities, and seek evaluation for any significant abdominal pain, LUQ pain or L shoulder pain (referred from spleen, Kehr’s sign) that might represent splenic injury o Splenic rupture: may require emergent splenectomy; some may be closely observed to retain spleen Transfuse as necessary • Corticosteroids (prednisone 40-60mg/d) indicated for airway obstruction, severe thrombocytopenia or hemolytic anemia o Some give for severe pharyngitis or constitutional sx (controversial) • Acyclovir, valacyclovir, ganciclovir: antivirals have no role in IM o Drugs reduce oral viral shedding, but no clinical benefit observed in trials Selected Drug Comments Drug Recom Acyclovir No pro Ganciclovir Though FOLLOW UP • • • • Fatigue may persist after IM in 10-20% > month o Customary advice is to increase activities as tolerated Enforced bedrest is counterproductive Some information is suggestive that IM is associated with subsequent increased risk of Hodgkin’s lymphoma or multiple sclerosis[22][17] By age 40, an estimated 95% of adults are infected Spleen size may be normally increased in some taller individuals, so splenomegaly "persisting" beyond four weeks may be a normal variant (3-7%) [20] OTHER INFORMATION • • • • By definition, infectious mononucleosis is only caused by primary EBV infection Other infectious causes should be described as causing a mononucleosis-like syndrome Pharyngitis and abnormal LFTs tip-off toward IM rather than GAS pharyngitis Roommates, household contacts: no increased risk IM routinely EBV-specific antibody profile helpful especially if heterophile (-) IM EBV capsid IgM & IgG (+) with EBNA (-) = IM-if sx < 4-6wks o Acute EBV excluded if (+) EBNA since EBNA only expressed >6wks acute infection as latency established EBV is not a cause of Chronic Fatigue Syndrome (although can cause postinfectious fatigue after IM in ~10%) DON’T draw serologies for chronic fatigue sx. no data to support as a cause o • Basis for recommendation Lennon P, Crotty M, Fenton JE Infectious mononucleosis BMJ 2015;350:h1825 [PMID:25899165] Comment: Direction to frequent clinical diagnostic, therapeutic problems as well as return to sports that face practioners Most is expert opinion based on thin data such as retrospective or observational studies rather than RCTs Tynell E, Aurelius E, Brandell A, et al Acyclovir and prednisolone treatment of acute infectious mononucleosis: a multicenter, double-blind, placebocontrolled study J Infect Dis 1996;174(2):324-31 [PMID:8699062] Comment: The combination of corticosteroid and acyclovir offered no clinical benefit in IM References Andrei G, Trompet E, Snoeck R Novel Therapeutics for Epstein⁻Barr Virus Molecules 2019;24(5) [PMID:30871092] Comment: As existing antivirals have little effect on EBV, there is much interest in new approaches especially for PTLDS, HLH-related disease and CAEBV Risma KA, Marsh RA Hemophagocytic Lymphohistiocytosis: Clinical Presentations and Diagnosis J Allergy Clin Immunol Pract 2019;7(3):824-832 [PMID:30557712] Comment: General overview of HLH including genetic and sporadic 5 Bollard CM, Cohen JI How I treat T-cell chronic active Epstein-Barr virus disease Blood 2018;131(26):2899-2905 [PMID:29712633] Comment: Dr Cohen has the most experience with CAEBV in the U.S HSCT is the only true curative option suggesting that early diagnosis is important to allow sufficient health for good outcomes Kimura H, Cohen JI Chronic Active Epstein-Barr Virus Disease Front Immunol 2017;8:1867 [PMID:29375552] Comment: Mechanisms are not completely understood, but in CAEBV, host responses don’t control the virus resulting in markedly elevated levels of EBV DNA in the blood and infiltration of organs by EBV-positive lymphocytes Patients often present with fever, lymphadenopathy, splenomegaly, EBV hepatitis, or pancytopenia Over time, these patients develop progressive immunodeficiency and if not treated, succumb to opportunistic infections, hemophagocytosis, multiorgan failure, or EBV-positive lymphomas Patients with CAEBV in the United States most often present with disease involving B or T cells, while in Asia, the disease usually involves T or NK cells The only proven effective treatment for the disease is hematopoietic stem cell transplantation Marsh RA Epstein-Barr Virus and Hemophagocytic Lymphohistiocytosis Front Immunol 2017;8:1902 [PMID:29358936] Comment: Consider in patients with IM who don’t improve after weeks with continued fever, perhaps progressive jaundice, LFT abnormalities and severe cytopenias Bozlak S, Varkal MA, Yildiz I, et al Cervical lymphadenopathies in children: A prospective clinical cohort study Int J Pediatr Otorhinolaryngol 2016;82:81-7 [PMID:26857321] Comment: Infections was the leading category in the 41.3% of patients with diagnosed entities (of 218 total) in this study from Turkey Of the 27% (n = 59) with infections, EBV was thought to be responsible for 27% De Paor M, O'Brien K, Fahey T, et al Antiviral agents for infectious mononucleosis (glandular fever) Cochrane Database Syst Rev 2016;12:CD011487 [PMID:27933614] Comment: Seven RCTs examined that judge the effectiveness of antivirals (acyclovir, valomaciclovir and valacyclovir) in IM Authors judge the quality of evidence as very low The majority of included studies were at unclear or high risk of bias and so questions remain about the effectiveness of this intervention Although two of the 12 outcomes have results that favor treatment over control, the quality of the evidence of these results is very low and may not be clinically meaningful Rezk E, Nofal YH, Hamzeh A, et al Steroids for symptom control in infectious mononucleosis.Cochrane Database Syst Rev 2015 [PMID:26558642] Comment: This 2015 update of earlier 2012 did not find any new data compared to the earlier Cochrane review that examined seven trials with a total of 362 participants Available data was low quality with nothing to support their use; however, this is due to the paucity of trials 11 Dunmire SK, Grimm JM, Schmeling DO, et al The Incubation Period of Primary Epstein-Barr Virus Infection: Viral Dynamics and Immunologic Events PLoS Pathog 2015;11(12):e1005286 [PMID:26624012] Comment: On average, patients come to clinical attention about six weeks after acquisition of primary EBV These authors had a prospective longitudinal cohort and were able to follow events in the pre-patent period They found little virus in oral secretions until week before symptom onset Authors postulate that clinical EBV therefore is a result of the loss of viral replicative control backed up by finding only high levels of virus just about the same time or at the time of clincial presentation Very low levels of EBV in blood were detected ~ wks prior There was no expansion of cytotoxic T cells (CD8) in this early perior and only upon onset of high level virus and clinical disease 12 Ali AS, Al-Shraim M, Al-Hakami AM, et al Epstein- Barr Virus: Clinical and Epidemiological Revisits and Genetic Basis of Oncogenesis Open Virol J 2015;9:7-28 [PMID:26862355] Comment: Review of malignancies with certain and associated EBV including Burkitt’s lymphoma, Hodgkin’s disease , post-transplant lymphoproliferative disorders (PTLD) and T-cell lymphomas (e.g Peripheral T-cell lymphomas; PTCL and Anaplastic large cell lymphomas; ALCL) It is also linked to epithelial tumors such as nasopharyngeal carcinoma (NPC), gastric carcinomas 13 Höcker B, Fickenscher H, Delecluse HJ, et al Epidemiology and morbidity of Epstein-Barr virus infection in pediatric renal transplant recipients: a multicenter, prospective study Clin Infect Dis 2013;56(1):84-92 [PMID:23042966] Comment: Small prospective study of primary EBV infection in children with renal transplants found no correlation with intensity or duration of EBV viral load for post-transplant lymphoproliferative disorder Study was too small to determine if other factors at play 14 Balfour HH, Odumade OA, Schmeling DO, et al Behavioral, virologic, and immunologic factors associated with acquisition and severity of primary Epstein-Barr virus infection in university students J Infect Dis 2013;207(1):808 [PMID:23100562] 10 Comment: Prospective study starting with US college freshmen/women demonstrated that IM is still the "kissing disease." In this study, 546 students screened, 202 (37%) were antibody negative and 143 antibody-negative students were enrolled During a median of years of observation, 66 subjects experienced primary infection Of these, 77% had infectious mononucleosis, 12% had atypical symptoms, and 11% were asymptomatic Subjects reporting deep kissing with or without coitus had the same higher risk of infection than those reporting no kissing (P < 01) Viremia was transient, but median oral shedding was 175 days Severity of illness correlated positively with both blood EBV load (P = 015) and CD8(+) lymphocytosis (P = 0003) Study take home points for this author is that this is one of the first "modern" studies in years Over one-third of US students in this Midwest university were EBV seronegative Also, the majority were symptomatic with infection Although some have suggested EBV is an STD, this was not supported in this study As others have found, severity of infection is likely a consequence a vigorous, mainly cytotoxic T cell immune response Rating: Important 15 Green M, Michaels MG Epstein-Barr virus infection and posttransplant lymphoproliferative disorder Am J Transplant 2013;13 Suppl 3:41-54; quiz 54 [PMID:23347213] Comment: Helpful and thorough review of PTLD management, which is beyond the scope of this module Traditionally, lowering immunosuprpression is the key strategy, although other therapies, including the rituximab (anti-CD20 monoclonal antibody) and traditional chemotherapy are used at times 16 Montoya JG, Kogelnik AM, Bhangoo M, et al Randomized clinical trial to evaluate the efficacy and safety of valganciclovir in a subset of patients with chronic fatigue syndrome J Med Virol 2013;85(12):2101-9 [PMID:23959519] Comment: Small study suggesting benefit in patients with elevated titers to EBV and HHV-6 IFteb sycg small studies (n=30) don’t hold up in larger studies when considering this likely heterogenous disorder 17 Handel AE, Williamson AJ, Disanto G, et al An updated meta-analysis of risk of multiple sclerosis following infectious mononucleosis PLoS One 2010;5(9) [PMID:20824132] Comment: Authors expand upon a prior meta-analysis but incorporating newer, larger studies They found a risk (RR) 2.17 for MS following IM 18 Higgins CD, Swerdlow AJ, Macsween KF, et al A study of risk factors for acquisition of Epstein-Barr virus and its subtypes J Infect Dis 2007;195(4):474-82 [PMID:17230406] Comment: One of several studies perhaps suggesting a role of sexual transmission for EBV What is difficult is to divorce potential oral from genital exposures 19 Sokal EM, Hoppenbrouwers K, Vandermeulen C, et al Recombinant gp350 vaccine for infectious mononucleosis: a phase 2, randomized, double-blind, placebo-controlled trial to evaluate the safety, immunogenicity, and efficacy of an Epstein-Barr virus vaccine in healthy young adults J Infect Dis 2007;196(12):1749-53 [PMID:18190254] Comment: This phase II vaccine study sought to determine whether acute EBV infection or IM could be prevented through the immunization of naive young adults This was a randomized, double-blind trial using a recombinant gp350 vaccine that prompts antibody development against a key viral antigen that facilitates EBV entry into B lymphocytes Immunizations were carried out at initiation, and at month and months, with follow-up for a total of 18 months The authors found that immunization with the gp350 vaccine yielded detectable antibody response in 98.7% of subjects (95% CI, 85.5-97.9%) By the end of the 18 month study period, the primary end point of preventing IM showed an efficacy of 78% (95% CI, 1- 96%), but did not halt asymptomatic acquisition of EBV Adverse side effects were no different between the vaccine and placebo groups The group receiving the gp350 vaccine had no cases of IM once the three series of immunizations were completed, compared to the placebo group that continued to develop IM This trial suggests that in the intent-to-treat analysis, the gp350 vaccine was protective against the development of IM — although the small study design guaranteed wide confidence intervals Immunization appeared to be safe and it generated reliable seroconversion, suggesting that the vaccine is a candidate for study in larger populations Whether such a vaccine can interrupt the malignancy potential of EBV depends on whether the significant immune dysregulation as a consequence of IM is a leading driver If, instead, oncogenic potential is related to viral infection alone, then this vaccine is unlikely to yield this specific benefit, since it does not appear to halt acquisition of the EBV virus Regardless, since there is no reliable medical therapy for IM that shortens illness or postinfectious fatigue duration, a vaccine strategy could well be worthwhile in industrialized countries where there is some evidence suggesting that IM is increasing in incidence as well as severity Given the immunological complexity of EBV infection, the question of whether a vaccine stra Given the immunological complexity of EBV infection, the question of whether a vaccine strategy can be safely employed will not be quickly answered, as longterm studies will likely be needed ... offered no clinical benefit in IM References Andrei G, Trompet E, Snoeck R Novel Therapeutics for Epstein? ??Barr Virus Molecules 2019;24(5) [PMID:30871092] Comment: As existing antivirals have little... of HLH including genetic and sporadic 5 Bollard CM, Cohen JI How I treat T-cell chronic active Epstein- Barr virus disease Blood 2018;131(26):2899-2905 [PMID:29712633] Comment: Dr Cohen has the... diagnosis is important to allow sufficient health for good outcomes Kimura H, Cohen JI Chronic Active Epstein- Barr Virus Disease Front Immunol 2017;8:1867 [PMID:29375552] Comment: Mechanisms are not