Transcript Epstein-Barr Virus

Epstein-Barr Virus
Terry Kotrla, MS, MT(ASCP)BB
Diseases

African or Burkitt’s Lymphoma
– malignant B-cell neoplasm
– presents as a rapidly growing tumour of the
jaw, face or eye
– grows very quickly, and without treatment
most children die within a few months
– Epstein-Barr virus (EBV) has been strongly
implicated
African or Burkitt’s Lymphoma


Although BL is a very rapidly growing tumour it
responds well to treatment.
Three pictures: before treatment, 3 days and 6
days after treatment
Nasopharyngeal Carcinoma






Endemic in South China, Africa, Arctic Eskimos
This is a malignant tumour of the squamous
epithelium of the nasopharynx.
100% contain EBV DNA
Rates are less than 1 per 100,000 in most
populations
Nasopharyngeal carcinomas are found in
association with reactivation of latent EpsteinBarr Virus.
The exact mechanisms of association are
unknown
B-Cell Lymphoma
In most individuals infected with EBV, the virus
is present in the B-cells, which are normally
controlled by T-lymphocytes
 When T-cell deficiency exists, one clone of EBVinfected B-lymphocytes escapes immune
surveillance to become autonomously
proliferating.
 EBV induced B cell lymphomas are most
prevalent in immunocompromised patients.

Oral Hairy Cell Leukoplakia
Viral infection of the oral cavity.
 Indicator of HIV infection as well as of a
person's lessening or weakening immunity

Infectious Mononucleosis

Downey cells may be present
Heterophile Antigens/Antibodies
An antigen or antigenic determinant which
is found in different tissues in more than
one species.
 These are antibodies found in one specie
of animal (such as humans) which react
against a component of another specie.

Paul Bunnell Test




The original Paul-Bunnell test was a simple titration of sheep cell
agglutinins but this procedure was subsequently modified in order to
distinguish between sheep cell agglutinins formed in IM and the
Forssman-type antibodies found in normal serum, serum sickness
and in certain other conditions.
Tissues rich in Forssman antigen (guinea pig kidney) absorb
Forssman antibodies but do not affect the heterophil antibodies in
IM.
Heterophil antibodies are absorbed by beef cells,
Forssman hapten is a glycolipid usually associated with a protein,
the determinant being largely carbohydrate and therefore heat
stable.
Davidsohn Differential



The principle behind the Paul-Bunnell-Davidsohn test is that the two
types of sheep agglutinins are distinguished by titrating them before
and after absorption with guinea pig kidney and ox cells.
Patients serum containing antibodies due to IM is added to guinea
pig kidney cells. These antibodies are not absorbed by the kidney
cells. These antibodies then react with Beef (Ox) red blood cells
which causes agglutination and is a positive test for IM.
Patients serum containing Forssman antibodies are added to guinea
pig kidney cells. Antibodies are absorbed by the kidney cells. These
antibodies are then allowed to react with Beef red blood cells which
does not cause agglutination. This is a positive test for Forssman
antigens.
Davidsohn Differential
* To be considered absorbed there must be greater than a three tube
difference between the presumptive titer and the differential titer.
Heterophil Antibody
------------------------
Kidney Extract
------------------
Beef Erythrocyte
---------------------
Infectious Mono
Not Absorbed
Absorbed
Forssman
Absorbed
Not Absorbed
Serum Sickness
Absorbed
Absorbed
Davidsohn Differential
Advantages

When properly performed, this
test is specific for Infectious
Mononucleosis and falsepositive results are rare.
Disadvantages

Davidsohn Differential test is
very time consuming and
burdensome.