Flashcards in 3.26.14* Ryan - Viral Hematology Deck (19):
CMV, EBV, KSHV (HHV-8) are what kind of virus
a. subsets of herpes virus, enveloped dsDNA.
all attack lymphocytes
what are oncogenic the viruses
MOA of antiviral drugs
inhibit replication. Can still lead to oncogenesis due to latency.
What are the steps of CMV infection?
a. infect/replicate in epithelial cells
b. spread to lymphoid tissue
c. become latent in B and T cels and monocytes
d. childhood infections are asymptomatic, adult infects may lead to mono/fever. AIDs patients may get retinitis, colitis, and pneumonia
CMV VS TRANSPLANT PATIENTS
Infection can occur by receipt of CMV+ organ or by reactivation of CMV+ recipient/ Most severe outcome is pneumonia about 1-4 months after transplant (preceded by fever).
CMV: Diagnosis and Treatment
Detection of large lymphocytes
Diagnosed by ELISA, PCR or shell vial assay.
Treatment: Selective prophylaxis with CMV Ig and ganciclovir-
a. 90% of population. Teens get mono.
EBV in AIDs patients
EBV in transplant patients
posttransplant lymphoproliferative disease
EBV in normal patients
Burkitt lymphoma and nasopharyngeal carcinoma
a. Spread through saliva. Incubation period is several weeks. Initial replication in oropharyngeal epithelium, spread to lymphocytes and then liver and spleen. EBV remains latent in throat epithelia and B cells, there can be oral shedding for weeks.
Productive infection of tongue epithelial cells. Rarely seen except in AIDS patients.
How to diagnosis EBV infectious mononucleosis:
a. Diagnosed by symptoms and >50% atypical, large lymphocytes
b. Diagnostic markers
-EB nuclear antigens (EBNAs) assist in transcription and genome replication
-Viral capsid antigen (VCA) is produced during lytic replication
Because anti-VCA rises before anti-EBNA:
An anti-VCA+, anti-EBNA- patient is considered to have a primary infection
An anti-VCA+, anti-EBNA+ patient has had a past infection
Posttransplant lymphoproliferative disease
Caused by EBV infection leaking to B cell lymphoma in transplant patients. Highest risk among seronegative recipients during the first year posttransplant
Treatment: stop immunosuppression
Neoplasm of B-cells that affects bones of the jaw. Nearly all have overproduction of MYC.
Endemic in central Africa, typically young children
Both can cause mono and are latent in B cells. Both can cause post-transplant complications, but presentation is different. CMV is sexually-transmitted and a source of congenital infections. CMV is always heterophile antibody negative. EBV is a known oncogenic virus.
Necessary but not sufficient to cause Kaposi’s sarcoma (KS)
a. DNA can be amplified from B-cells of classical KS and AIDS KS patients
Now, 95% of infections are asymptomatic, can be mild when symptomatic.
Tumor-specific treatment or target HIV, but not HHV-8.
primary effusion lymphoma
multicentric Castleman's disease