Infectious Mononucleosis And Mumps

Front 1

Herpes virus morphology/classification

What are its layers?

Back 1

enveloped, double stranded DNA virus

Envelope - glycoproteins
Tegument - polymerase
Nucleocapsid

Front 2

What are the 3 major subfamilies of herpes virus that infects humans?

Where do they establish latency?

Back 2

1. alpha (HSV1,2, VZV, herpes type B)
-latency in neurons

2. Beta (CMV, HHV6, 7)
-Latency in monocytes and lymphocytes

3. Gamma (EBV, HHV8)
-latency in B cells

Front 3

How is EBV transmitted?

Back 3

saliva

Front 4

What are the EBV receptors and where are they located?

Co-receptor?

Back 4

CD21 or CR2 (C3d complement receptor) on B cells and oral epithelial cells

Co-receptor is MHC class II molecules on B cells

Front 5

In EBV viremia, approx. what percentage of B cells are infected?

Back 5

20% of B cells

Front 6

What happens in EBV infection
a. initially
b. mid to late

Back 6

a. Lytic infection of B cells, viremia

b. EBV establishes latency --> replicates as an episome

Immortalizes B cells --> polyclonal activation of B cells --> secretion of non-EBV antibodies, activates Cyt T cells --> kills B cells --> symptoms

Front 7

Why are antiviral drugs ineffective against EBV infection?

Back 7

Antivirals are only effective against actively replicating virus

Symptoms of EBV occur after lytic cycle has been completed, and T cell response to latent infection kills B cells

Front 8

What are 2 early antigens of EBV?

When are they expressed, and why is this important?

Back 8

polymerase and thymidine kinase

Expressed in lytic infection, site of antiviral activity

Front 9

What are the viral capsid antigens (VCAs) of EBV?

When are they expressed and what are they required or?

Test for these?

Back 9

late structural genes

Expressed in lytic infection, used for production of mature virions

Serology ordered - IgG and IgM antibodies to these antigens

Front 10

What are the EBNA (nuclear antigens) required for?

When are they expressed?

Back 10

antigens required for maintenance of latent infection

Expressed after resolution of acute infection

Front 11

What are the latent membrane proteins (LMPs)?

Test for these?

Back 11

membrane proteins of EBV that have a role in malignancy

LMP1 - stimulates B cells through CD40

LMP2 - bridges B-cell receptor with Ig --> stimulates proliferation

No serological test

Front 12

What is the monospot test?

For whom is the test diagnostic?

Back 12

Diagnosis of EBV mononucleosis

Looks for heterophile antibodies produced by EBV-infected B cells (doesn't actually find EBV) by presenting antigens on RBCs --> look for agglutination

Diagnostic for EBV in people over 5 years old

Front 13

What is the serologic time course of...
a. IgG-VCA
b. IgM-VCA (<4yrs)
c. IgM-VCA (>4yrs)
d. Early antigen
e. Nuclear antigen

Back 13

a. peaks at 2 weeks, persists for years
b. peaks at 2 weeks, out by 4 weeks
c. peaks at 2 weeks (higher), out by 3 months
d. Peaks in 2 months
e. Low level, increases over months-years, lifelong

Front 14

What is the time course for VCA IgG in acute infection
a. before
b. acute
c. convalescence

Back 14

a. none
b. +
c. +

Front 15

What is the time course for VCA IgM in acute infection
a. before
b. acute
c. convalescence

Back 15

a. none
b. +
c. none

Front 16

What is the time course for Early Antigen in acute infection
a. before
b. acute
c. convalescence

Back 16

a. none
b. +
c. some

Front 17

What is the time course for EBNA in acute infection
a. before
b. acute
c. convalescence

Back 17

a. none
b. none
c. +

Front 18

What is the peak infectious mononucleosis age?

Back 18

20

Front 19

How long can shedding of EBV last after acute infection?

Back 19

months

shedding rate 50-100%

Front 20

What is the incubation time for EBV mono?

Back 20

15-45 days

Front 21

What are symptoms of EBV mono?

Back 21

1. Acute sore throat with exudative tonsillitis
2. Fever
3. malaise
4. myalgia
5. headache
6. lympadenopathy
7. hepatosplenomegaly

Front 22

What are 7 types of lymphoma that are complications of EBV lymphoproliferative syndrome?

Back 22

1. Endemic Burkitt's lymphoma
-malignant tumor of jaw and viscera
-endemic to malaria-prevalent regions

2. Non-endemic Burkitt's lymphoma
-only 20% EBV positive, less strong of a link

3. Nasopharyngeal carcinoma (China)

4. Hodgkin's - 50%

5. non-Hodgkins in HIV

6. CNS lymphoma in AIDS

7. Post-transplant lymphoproliferative disorders
-hairy leukoplakia in profound immunosuppression

Front 23

What are 5 differential diagnoses of EBV mono?

Back 23

1. falso monospot test (in kids < 5yo)
2. CMV mono
3. Acute retroviral syndrome
4. Adenoviral pharyngitis
5. Streptococcal pharyngitis

Front 24

How is CMV transmitted?

Back 24

Saliva
Respiratory droplets (large)
Semen
Blood
Transplacental
Post-op

Front 25

What types of infections does CMV cause and to which types of cells

Back 25

1. Productive, lytic, acute infection
-fibroblasts, epithelial cells, macrophages, lymphocytes


2. Latent infection (for life)
-T cells, macrophages

Front 26

What are 4 ways in which the pathogenesis of CMV is different from EBV?

Similar?

Back 26

1. CMV does not immortalize cells
2. Symptoms less severe than EBV
3. Monospot negative
4. EBV IgM negative, CMV IgM pos.

Front 27

What is signficant about the histology of CMV

Back 27

'owl eye' inclusions

Front 28

Clinically, how does CMV infection look?

Back 28

Most commonly asymptomatic

Infectious mononucleosis type syndrome
-20% of cases
-similar to EBV clinical, but less specific

Front 29

What happens in CMV-causing congeital infection?

What are the sequelae?

Back 29

Transmission of CMV in utero to fetus (among the TORCH organisms) --> congenital abnormalities

-small, microcephalic, deaf, mental retarded, jaundice, thrombocytopenia..death

Front 30

What are 4 CMV therapeutics?

Back 30

Ganciclovir - chain terminator but poor bioavail.
Valganciclovir
Foscarnet
Cidofovir - chain terminator

Front 31

What 5 syndromes can CMV cause?

Back 31

1. GI - colitis, esphagitis, pan-enteritis
2. Eye-chorioetinitis
3. Lungs - pneumonitis
4. Nervous - encephalitis, menengitis, myelitis
5. Graft failure in transplant patients

Front 32

Mumps -
a. virus?
b. nucleic acid?
c. morphology

Back 32

a. paramyxovirus
b. neg. ss RNA, unsegmented
c. helicial nucleocapsid, enveloped
hemagglutinin-neuraminidase, fusion protein

Front 33

Mumps virus
a. transmission
b. replication
c. type of infection
d. spreads to where?

Back 33

a. respiratory, saliva
b. epithelial cells of nasopharynx
c. lytic infection.
d. Parotid gland

Front 34

Symptoms of mumps

Back 34

Headache, malaise, low fever
parotitis (30-40%)

Front 35

What are complications of mumps? (3)

Back 35

CNS - meningitis, encephalitis, deafness
orchitis --> sterility
pancreatitis

Front 36

How do you diagnose mumps?

Back 36

clinical - parotitis and fever
viral culture --> syncitia
PCR --> detect virus
Serologic --> IgM (acute), IgG

Front 37

How do you prevent mumps?

Back 37

vaccine

Front 38

What shows up on a CBC in EBV mononucleosis?

Back 38

1. Increase in lymphocytes (>50%)
2. Increase in atypical lymphocytes (>10%)
3. Development of heterophile antibodies - IgM, positive after 1 week
4. Development of anti-EBV antibodies

Front 39

What are some acute complications of EBV mono?

Back 39

1. Upper airway obstruction
2. Splenic rupture (esp. wit minor trauma) --> internal bleeding
3. CNS involvement - encephalitis, meningitis, myelitis
4. EKG abnormalities, myocarditis
5. Hemolytic anemia
6. Granulocytopenia
7. X-linked lymphoproliferative syndrome

Front 40

What happens in duncan's syndrome (x-linked lymphoproliferative disorder)?

Back 40

Defect in SLAM (T cell gene signaling lymphocyte activation)

In 1/3 - excessive T cell suppression leads to hypogammaglobulinemia

In 2/3 - Burkitt's lymphoma