Epstein-Barr Virus Flashcards
What is the family?
Herpesvirus
Where does it replicate in? What does this cause?
Replicates in B lymphocytes and epithelial cells in oropharyngeal secretions, causing polyclonal growth stimulation and lymphoid hyperplasia
What does it cause in normal lymphocytes?
Immortalisation (continuously dividing cell line)
Expression of nuclear neoantigens (EB nuclear antigen)
What are the clinical features?
- Infectious mononucleosis
- Burkitt’s lymphoma
- Nasopharyngeal carcinoma
- Immunoblastic lymphoma
- Chronic fatigue syndrome
What are the clinical presentations of infectious mononucleosis?
- Glandular fever
- Lethargy
- Anorexia
- Pharyngitis
- Hepatosplenomegaly
- Lymphadenopathy
- Exudative tonsillitis
- Rash exacerbated by ampicillin
How long is the incubation period of infectious mononucleosis?
4 - 7 weeks
How is EBV transmitted?
Close-contact - “kissing disease”
Who is EBV most prevalent in?
Seronegative children and young adults
What are the complications of infectious mononucleosis?
- Hepatitis (may have jaundice, abnormal LFT)
- Pneumonitis
- Neurological (aseptic meningitis, encephalitis, myelitis, optic neuritis, acute cerebellar ataxia, Guillain-Barré syndrome, peripheral neuropathy, Bell’s palsy)
- Haematological (haemolytic anaemia, thrombocytopaenia, splenic rupture)
- Myocarditis, pericarditis
What do Burkitt’s Lymphoma cells express? Which chromosomal translocation is involved? Which areas does it occur?
- EBV markers (e.g. EBNA)
- 8;14 or 2;22 (deregulation of c-myc oncogene)
- Occurs in. holoendemic malaria in tropical Africa
Who is at risk for immunoblastic lymphoma?
Lymphoproliferative disorder in patients with impaired cell-mediated immunity (AIDS, iatragenically induced in organ transplant recipients)
How does chronic fatigue syndrome present?
Extreme fatigue, fever, sore throat, painful lymphadenopathy, muscle weakness, memory loss
How to diagnose?
- Atypical lymphocytosis and mononuclear cells (at least 10%)
- Paul-Bunnell Test - Heterophile antibodies (present in 90%)
- monospot screening test
- haemagglutinating Ab to sheep RBCs -> Ab removed by adsorption with ox RBC but not with guinea pig kidney - 90% of healthy adults have EBV Ab so EBV IgM useful confirmation for IM
- viral capsid antigen Ab
- EB nuclear antigen Ab
- early antigen Ab
How to treat?
Treat the symptoms
Avoid penicillin
Is there EBV vaccine?
Undergoing clinical trials