L74 Flashcards
What receptor confines the tropism of EBV?
CR2 receptor
Which tissues and cells does EBV infect?
B lymphocytes
Mouth & nose epithelium
Also an STI b/c in vaginal secretions from the cervical epi, but weird b/c no CR2Rs here
Can EBV have a lytic stage of infection?
Yes
In B cells & epithelium
Can EBV have a latent stage of infection?
Yes
More common in B cells
What genetic element allows EBV to become latent?
Episome
What is the worst case scenario of an EBV infection?
CANCER
What cancers are EBV associated?
B cell lymphoma - Burkitt
Nasopharyngeal carcinoma
Post transplant lympho-proliferative disorder (PTLPD)
Maybe other T & B lymphomas (Hodgkin’s)
Most common EBV disease in normal people.
Mono - aggultinin + !!
EBV transmission
Saliva
Blood product
Transplant
STI
How do you know staph vs EBV pharyngitis?
Present in clinic
Probably going to give penicillin (ampicillin)
EBV gets a RASH –> doesn’t get better
Which arm of the immune system is most important in controlling EBV latent infection?
T cells
What is a cue that a pt is EBV infected during the acute phase?
See atypical lymphocytes on peripheral blood smear
Describe the Ab response to EBV in terms of symptom progression.
- Before symptoms: IgM/IgG vs E antigens
- Symptomatic: IgM Abs that agglutinate!!!
- Resolving: Abs vs EBNA
What is EBNA?
Epstein Barr nuclear antigen
See Abs vs these - know infection is resolving
What is a neurologic disorder you might see with EBV in normal pts?
Guillain Barre - ascending paralysis
If an AIDs negative IC pt presents with falling CD4 ct + EBV infection, which clinical disease are you thinking of?
B cell (Burkitt) lymphoma May present w/ malaria
Which EBV infection is most common in HIV pts?
Hairy oral leukoplakia
Which EBV infection is most common in transplant pts?
Post transplant lympho proliferative disorder
Describe the progression of PTLD.
Early = benign growth that respond to anti-virals Late = malignant growths
How does PTLD present on histo?
HISTO: multi-nucleated giant cells
Diagnose EBV
- PCR for EBV DNA
2. Immunocytochem for EBV proteins
EBV prophylaxis
Acyclovir
Gancyclovir (valgan)
Treat EBV mono
Supportive
Severe: steroids - prevent spleen damage
Can you treat EBV cancers with anti-virals?
No you dummy
That’s why you don’t what to progress this far - need chemo
Treat PTLD
Non-specific immunoglobulin
IFNa
Chemo
Rituximab (anti-CD20)
Name the 2 big diseases caused by VZV.
Chicken pox
Shingles
What does the chicken pox rash look like?
Infects EPI cells - duh, why its a rash!
Blistering rash
May also be pustular
At all different levels of progression
Why does it matter that VZV is neurotropic?
Reactivate (Shingles) = painful lesions
When in the disease does the chicken pox rash occur?
2nd!
Infection
1. Prodrome viremia = 9-13 days post-infection
2. Rash on face/scalp first, then trunk = 10-20 days post-infect
Where does VZV lie dormant?
DRG
CN ganglia
Who is most likely to get chicken pox complications?
IC pts: newborns, pregnant, transplant, AIDs
Complications of chicken pox
CNS
Lungs: pneumonitis
Liver
Reye’s syndrome - aka don’t give aspirin to kids!!!
Hallmarks of Shingles rash
Vesiculopustular
Painful
Stops at midline
Shingles complications
Post-herpetic neuralgia
If CN 5 involvement –> encephalitis
What is the Shingles complication if there is geniculate ganglion involvement?
Ramsey Hunt Syndrome
- 1 sided facial palsy
- Lesions in ear
- Loss taste ant 2/3 tongue
Immune response to VZV
IgM + IgG - limit spread
CD4 - resolve rash
You’re probably diagnosing CP/Shingles clinically, but if you really wanted to what test would you order?
Pap smear of a lesion
Direct fluorescent Ab
PCR of CSF if neuro involvment
What is the chicken pox vaccine?
Live, attenuated
2 shots
Prevents chicken pox in kids & decreases shingles in elderly
Which vaccine do you give to IC pts?
VZIG = immunoglobulin
Ex: pregnant women who have been exposed to chicken pox
Babies whose mothers have chicken pox
When and how do you treat chicken pox?
24 hrs of 1st lesion: PO acyclovir
Otherwise supportive
How do you treat IC pts with chicken pox?
Acyclovir IV
When and how do you treat Shingles in normal pts?
72hrs of 1st lesion: 7 day course of PO
- Acyclovir
- Famciclovir
- Valacyclovir
Which shingles complication/presentation should you always treat?
Opthalmic zoster
How do you treat shingles in IC pts?
IV acyclovir
Goal: decrease severity + speed healing
When does HHV 6 infection occur in life in comparison to CMV and EBV?
Earlier in life!
Which skin disease is most common in kids due to HHV6?
Roseola = exanthem subitum
1. Fever
Followed by
2. Red, raised rash w/o fever
Which conditions would clue you into an HHV 6 infection in kids AND adults?
Mono
Seizures in kids
Delayed bone marrow grafts in bone marrow transplant pts
DRESS syndrome = drug rxn eosinophila w/ systemic symptoms
Diagnose HHV6 infection.
Clinical
Serology: IgM & IgG
PCR
What 3 characteristics are unique about HHV8?
- Tumor promoting genes
- Lympho AND angiotrophic
- Has proteins homologous to cell proteins
Which tissues does HHV8 infect?
Uro & GI epithelium
How does HHV8 lie latent?
Episome - contributes to oncogenic reactivation
Where in the world are HHV8 infections most prevalent?
Mediterranean + Africa
HHV8 transmission
Sex***
Mom-baby
Oral
Blood
