Exam #7: Viral Infections of the Circulatory, RES, & Lymphatic System Flashcards Preview

Microbiology > Exam #7: Viral Infections of the Circulatory, RES, & Lymphatic System > Flashcards

Flashcards in Exam #7: Viral Infections of the Circulatory, RES, & Lymphatic System Deck (62):
1

List the characteristics of EBV.

- Herpesvirus (lytic & latent phases)
- Enveloped
- dsDNA

2

List the diseases that are associated with EBV. What patient populations are most likely to develop the different diseases associated with EBV?

- Mononucelosis-- adolescents & adults
- Oral Hairy Leukoplakia--Immunocompromised
- Burkitt's Lymphoma--children in central Africa
- Hodgkin's Disease--Multiple populations
- Nasopharyngeal Carcinoma--Southeast Asia & China
- PTLD--Transplant patients

3

What diseases associated with EBV are caused by the productive phase?

Mononucleosis
Oral Hairy Leukoplakia

4

What diseases associated with EBV are associated with the latent phase?

Burkitt's Lymphoma
Hodgkin's Disease
Nasopharyngeal Carcinoma
PTLD

5

What does EBV use for attachment & entry?

The receptor for the C3d component of compliment, which is found on a limited number of cells, including B-cells & epithelial cells of the oro & nasopharynx

6

Where does EBV replicate?

- Initially, EBV replicates with oral epithelial cells & causes lysis
- After lysis of epithelial cells, EBV infects B-cells

7

How is EBV transmitted?

Saliva

8

Describe the pathology of EBV.

- Initially, EBV replicates with oral epithelial cells & causes lysis
- After lysis of epithelial cells, EBV infects B-cells
- B-cell infection causes B-cells to differentiate into lymphoblasts
- Lymphoblasts proliferation leads to high levels of antibodies that bind antigens other than EBV, called heterophile antibodies
- In the first few days of infection, a robust cytotoxic T-cell immune response targets & kills EBV-infected immune cells, which leads to the symptoms of mononucleosis
- Some EBV-infected B-cells evade cytotoxic T-cells & become memory B-cells that can be reactivated

9

What are the symptoms of EBV reactivation?

In healthy individuals, none--asymptomatic

10

What EBV genes are associated with carcinogenesis?

1) Latent Membrane Protein 1 (LMP1)= CD40 homologue that is constitutively active & results in increased growth & suppressed apoptosis
2) Latent Membrane Protein 2 (LMP2)= increased growth of B-cells
3) EBNA1= inhibits apoptosis

11

When are EBV primary infections most common worldwide, & in the US?

World= <5
US= teens

12

What are the symptoms of mononucleosis?

Fever
Malaise
Exudative pharyngitis
Splenomegaly
Tender lymphadenitis

13

What biochemical marker is diagnostic for mononucleosis?

Heterophile antibodies

14

What complication is associated with mononucleosis?

Splenic rupture; thus, patients with mononucleosis are in instructed to refrain from physical exertion

15

What causes the symptoms of mononucleosis?

Cytotoxic T-cell response to EBV infected B-cells

16

What can happen when a patient with mononucleosis is given ampicillin?

Rash

17

How long is the typical incubation period in mononucleosis?

2 month incubation period

18

When are heterophile antibodies detected in mononucleosis?

A few days into symptomatic infection

19

What antibodies are associated with early EBV infection?

Anti-EA (Early Antigen)
Anti-VCA, IgM (Viral Capsid Antigen)

20

What antibodies are associated with late EBV infection?

Anti-EBNA (Epstein Barr Nuclear Antigen)
Anti-VCA, IgG

21

How is mononucleosis diagnosed?

- Mono spot test= heterophile antibody agglutination of sheep or horse RBCs
- Antibodies to EBV--mainly IgM to viral capsid antigen (VCA)

22

What are Downey cells?

Large atypical T-cells that have an indented cell margin are a classic feature of EBV infection

23

How is there a vaccine for mononucleosis?

No

24

How is mononucleosis treated?

- Rest & hydration
- Avoidance of strenuous activity

*Don't want splenic rupture

25

What effect do antiviral drugs have on EBV infection?

None really--symptoms are due to the immune response to the virus, NOT the virus itself

*Acyclovir will inhibit the viral polymerase, but it does not have an impact on the clinical course of the disease

26

What is Oral Hairy Leukoplakia?

Wart-like pattern on lateral surface of the tongue
- Seen in patients with immuosuppresion (~300 CD4+ T-cells)

27

How is Oral Hairy Leukoplakia treated?

- Antiherpetic drugs (acyclovir)
- Podophyllin resin

28

What is Burkitt's Lymphoma?

B-cell tumor often presenting in the jaw of children

29

What genetic mutations are associated with Burkitt's Lymphoma?

- Translocation (8 x 14) of the c-myc oncogene being put under the control of a very active promoter e.g. immunoglobulin genes
- Leads to high levels of c-myc activity & a high proliferative index

*This is the most rapidly progressing human tumor

30

How is Burkitt's Lymphoma treated?

Chemotherapy, which has a 70-80% cure rate in children and young adults

31

What co-factors are associated with Burkitt's Lymphoma?

Immunosuppression is highly associated with Burkitt's Lymphoma, which is partly why there is a high incidence in areas where chronic malaria is endemic (central Africa)

32

What is Hodgkin's Disease?

B-cell cancer that is NOT associated with any specific translocations vs. Burkitt's lymphoma

33

What is the typical presentation of Hodgkin's Disease?

- Nontender, palpable lymphadenopathy in neck, supraclavicular, or axilla
- Mediastinal adenopathy
- Fever, night sweats, & weight loss

34

What is the hallmark of Hodgkin's Disease?

- Reed-Sternberg cell
- A large cell with two or more nuclei or nuclear lobes, each of which contains an eosinophilic nucleolus

35

How is Hodgkin's Disease treated?

Radiotherapy
Chemotherapy

*Not that localized Hodgkin's Disease is cured in >90% of patients

36

What is nasopharyngeal carcinoma?

Epithelial cancer that originates in the nasopharynx

37

Where is nasopharyngeal carcinoma prevalent?

SE Asia
Africa

38

What are the symptoms of nasopharyngeal carcinoma?

- Facial pain
- Feeling of fullness in the sinus or throat
- Hearing loss

39

How is nasopharyngeal carcinoma treated?

Radiotherapy
Chemotherapy

40

What is PTLD?

Post-transplantation Lymphoproliferative Disorder
- abnormal proliferation of lymphoid cells in a transplant patient

41

What are the symptoms of PTLD?

Fever
Fatigue
Weight loss
Progressive encephalopathy

42

What is the major risk factor for PTLD?

EBV at the time of transplant

43

How is PTLD diagnosed?

- Histological analysis of tissue
- Detection of EBV genomes by in situ hybridization

44

How is PTLD treated?

1st line= Reduce immunsuppression
2nd= Rituximab (anti-CD20 ab)
3rd= Conventional chemotherapy

45

List the characteristics of CMV.

Herpesvirus
Enveloped
dsDNA

46

What diseases can be caused by CMV? How are these disease states dependent on the immune status of the host?

- Normal individuals = Mononuceolsis-like disease
- Babies of seronegative mothers= Cytomogalic inclusion disease
- AIDS & severely immunosuppressed= Multisite symptomatic disease

47

How is CMV transmitted?

Bodily fluids
- Saliva
- Breast milk
- Urine
- Fomites
- Sex

48

How is CMV diagnosed?

Detection of viral DNA or virus culture from diseased tissue

49

How is CMV treated?

1st Line:
- Gancycloir= converted to viral polymerase inhibitor by CMV enzymes
- Valganciclovir= converted to gangyclovir in the body that has an increased bioavaliablity

2nd Line:
- Cidofovir= converted to viral polymerase inhibitor by cellular enzymes, but MORE TOXIC than gancyclovir
- Foscarnet= direct inhibitor of the CMV polymerase, but associated with renal toxicity

50

What toxicity is associated with Gancyclvir?

Bone marrow toxicity & drug-related neutropenia

51

What is CMV Infectious Mononucleosis-Like Illness?

CMV infection of immunocompetent school-aged children & adults that results in mononucleosis-like disease

52

What are the symptoms of CMV Infectious Mononucleosis-Like Illness? How can you tell the difference between CMV & EBV?

Fever
Fatigue
Pharyngitis
Downey Cells

*No heterophile antibody production in CMV
**Exudative pharyngitis & cervical lymphadenopathy are rare in CMV

53

What is Cytomegalic Inclusion Body Disease?

Disease of the newborn that is primarily seen in children born to mothers that suffered primary CMV infection in utero.

54

What symptoms are associated with Cytomegalic Inclusion Body Disease?

Hepatosplenomgealy
Jaundice
Petechaie/ Rash

And,
- Microcephaly
- Growth retardation

55

How is Cytomegalic Inclusion Body Disease prevented?

Interrupt CMV transmission in body fluids by:
- Handwashing
- Avoid sharing drinks & toothbrushes with young children
- Avoid contact with saliva when kissing a young child

Maternal treatment with CMV immunoglobulin during pregnancy

56

What is the most common viral pathogen complicating organ transplant?

CMV

57

What is the CD4 T-cell count of an AIDS patient presenting with CMV related disease?

Between 50 & 100

58

What diseases are caused by CMV that are seen in transplant recipients?

- CMV pneumonitis
- Ulceration of the GI Tract
- Increased risk of Graft vs. Host Disease

59

What diseases are caused by CMV in AIDS patients?

CMV Retinitis

60

How is CMV infection prevented in transplant recipients?

Donor matching
Prophylaxis
CMV Ig

61

How is CMV prevented in AIDS patients?

Maintenance therapy with antivirals when reaching threshold levels of CD4+ T-cells

62

How is CMV treated?

IV antivirals

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