This document summarizes infectious mononucleosis, also known as glandular fever. It is caused by the Epstein-Barr virus and results in fever, sore throat, lymphadenopathy, and an increased number of atypical lymphocytes. It is commonly seen in adolescents and young adults. The virus spreads through saliva and infects B cells. This causes a proliferation of infected B cells and symptoms like fever and sore throat. Complications can include neurological issues, splenic rupture, and some cancers. Diagnosis involves detecting heterophil antibodies, elevated lymphocytes including atypical ones, and viral antibodies. There is usually a self-limited course over 1-3 weeks.

1. INFECTIOUS MONONUCLEOSIS
Dr. SARANYA

2. Acute , self – limited disease of adolescents and young adults.
Caused by EPSTEIN – BARR VIRUS (EBV ): HERPES VIRUS FAMILY
Characterized by :
1.fever, sore throat & generalized lymphadenitis
2. Lymphocytosis of activated CD 8+ T cells
 Also known as GLANDULAR FEVER.
 Transmitted by person to person contact such as kissing with transfer of
virally contaminated saliva.

3. PATHOGENESIS
 1. In a susceptible sero negative host ( lack antibodies ),virus in
the contaminated saliva invades and replicates within
epithelial cells of the salivary gland, & then enters B cells in
the lymphoid tissue which possess receptor for EBV.
 The infection spread throughout the body via blood stream or
by infected B cells.
 2.Viremia and death of infected B cell cause acute febrile illness
& appearance of specific humoral antibodies ( peak about 2
week after infection & persist throughout life ). Apperance of
antibodies marks the disappearance of virus from the blood.

4.  3. EBV infected B cells undergo polyclonal activation & proliferation.
They secrete antibodies :initially IgM, later IgG.
IgM antibody is heterophile anti sheep antibody used for diagnosis of
IMN.
IgG Persist & provide immunity against re infection.
 Activate CD8+ Tcells( cytotoxic T cells/ SUPPRESSOR T CELLS)
: Killing of B cells & pathognomic ATYPICAL LYMPHOCYTE seen in
blood.

5. CLINICAL FEATURES
 Adolescents and young adults
 Incubation period 3-8 weeks

6. CLINICAL FEATURES
 During prodromal period ( first 3-5 days ): mild symptoms
 Frank clinical features ( next 7-21 days ) :
fever
sorethroat
bilateral cervical lymphadenopathy
splenomegaly ( 50%)
hepatomegaly (10%)
transient erythematous maculopapular rash
Most common

7. COMPLICATION
 Neurologic manifestation in children
 Splenic rupture due to splenitis
 Upper airway obstruction due to hypertrophied adenotonsillitis
 Autoimmune hemolytic anemia
 Malignancy (EBV ) : Nasopharyngeal carcinoma
B cell NHL
Burkitts lymphoma

8. LABORATORY FINDINGS
1. HAEMATOLOGIC FINDINGS :
 LEUKOCYTOSIS : > 50% are lymphocytes , >10% atypical lymphocytes (
mainly CD 8 + T cells )
These 12 -16 micrometer diameter, with oval, indented or folded
nucleus , abundant cytoplasm with few azurophilic granules.
 ESR elevated
 LFT : abnormal > 90% cases

10. Serological studies
• Detection of heterophil antibody(Ab capable of reacting with an
antigen that is completely unrelated to the antigen that had originally
elicited its production)
IgM class
Detectable during the second week of illness and persist for 2 months
Paul bunnell test
Paul bunnell davidsohn test(differential absorption test)
Rapid slide test

11. Paul bunnell test
• Mixing of sheep erythrocyte with serial dilutions of patients serum
and finding the agglutination titre(highest dilution at which
agglutination detected)
• Normal individual-1:56 or less
• IMN-1:224 or more
• High titre heterophil Ab also seen in lymphoma, leukemia and serum
sickness
• Requires clinical correlation

12. PB davidsohn test
• To differentiate heterophil Ab in IMN and non IMN disorders
• Het Ab in IMN-absorbed by by beef red cell not by guinea kidney cell
• Other disorder- absorbed by guinea kidney cells but not by beef red
cell
• Usually done when agglutination titre with sheep red cell is low while
clinical and hematological features are present

13. Rapid slide test(Monospot test)
• Simplest, widely used
• Mixing patients serum with either beef red cell or guinea pig kidney
cell on two halves of a glass slide
• Horse erythrocytes added
• Look for agglutination

14. EBV specific antibodies
• Antibodies directed against specific EBV antigens
• Viral capsid antigen
• Early antigen
• Epstein Barr nuclear antigen
• Presence of IgM anti VCA or EA-D antibodies and absence of anti
EBNA antibodies –diagnostic of acute IMN

15. Lymph node biopsy
• In case of atypical presentation
• Hyperplasia of paracortical zones due to proliferation of T
lymphocytes
• Mitotic activity increased
• Immunoblast- binuleate form-mimic RS cell in Hodgkin lymphoma
LFT
• Mild elevation of serum enzyme and bilirubin

16. THANK U