Polyoma viruses Flashcards
What are the two polyoma viruses? Prevalence?
JC and BK viruses
Ubiquitous; 80% of US adult population JC and BK seropositive
BK and JC viruses are (RNA, DNA) (single-, double- stranded) (linear, circular)
Circular ds DNA
Describe the replication of JC and BK virus
Occurs in kidney and respiratory tract
Early genes are alternatively spliced to produce small, medium, and large T antigens
Late genes encode caspid proteins
(T/F): Polyoma viruses are human oncogenic viruses
False - can transform non-permissive cells in non-humans
Where do JC and BK viruses lay latent?
Kidney
Describe the disease process of BK and JC virus in an immunocompetent host
Gets into respiratory tract –> replicates –> primary viremia –> replicates in kidney –> transient secondary viremia –> indefinite latency in kidney
Describe the disease process of BK and JC virus in an immunocompromised host
Gets into respiratory tract –> replicates –> primary viremia –> replicates in kidney –> transient secondary viremia –> reactivation due to immunocompromise –> JC viremia in CNS = PML and BK viremia in kidney = occasional hemorrhagic cystitis
From what source should you culture BK virus?
Urine
____ infects gray matter only; ___ infects white matter only; ____ infects white and gray matter
Rabies
JC virus/PML
Measles/SSP
What part of the CNS does JC virus infect?
Oligodendrocytes
Prognosis of PML?
Death usually within 3-6 months
An AIDS patient presents with hemiparesis, conjugate gaze abnormalities, and aphasia. Dx?
PML secondary to reactivated JC virus
How to diagnose PML?
White matter lesions on MRI, PCR
PML treatment?
Adjust HAART (50% fatality) Adjust immunosuppression (80% fatality)
Viral inclusion bodies in oligodendrocytes indicates which two disease?
PML, SSP
