Other hematologic viruses Flashcards
What viruse presents with an erythematous facial rash, joint swelling/pain, and anemia (often sub-clinical)
Parvovirus B19
Why should exposed women be tested for anti-B19 IgG?
Parvovirus B19 increases risk for fetal hydrops
How is transient aplastic crisis caused by parvovirus B19 Tx’d?
Blood transfusions and supprotive care
How is PRCA and and post-exposure pro-phylaxis of parvovirus B19 Tx’d?
Anti-B19 immunoglobulin
Lymphotropic herpes viruses
CMV; EBv, HHV-6, HHV-7, and HHV-8)
Where does EBv undrgo primary replication?
In the pharynx and salivary epithelial cells
Downey Cells
CD8+ T cells with abnormal lobular nuclei that rosette w/ RBCs
How does EBv cause leukemia/lymphoma?
EBv induces translocation of the c-myc proto-oncogene to the immunoglobulin locus - increases c-myc expression and transforms the host cells
If a patient lacks functional T cell responses, EBVmediated B cell transformation can cause leukemia or lymphoma
EBv results in what malignancies if AIDS or a transplant Pt is infected?
Hairy leukoplakia and B cell lymphomas
Malaria and EBv can result in what maligncancy?
African Burkitt lymphoma
DOC for CMV?
Ganciclovir and valganciclovir - inhibit DNA polymerase activity and cause chain termination
Side-effect of ganciclovir and valganciclovir
May cause severe neutropenia
What is used to Tx drug-resistant CMV (especially CMV retinitis)?
Foscarnet
Side-effects of foscarnet
Nephrotoxicity
Seizures
HHV6 and HHV7 cell tropism
CD4+ T cells
What virus is responsible for causing Kaposi’s sarcoma?
HHV-8
An HIV positive patient presents with skin, oral, and tongue lesions as shown in the photographs. His CD4+ T cell count is 48 cells/𝛍l. The patient is not currently receiving ART therapy. Which viral pathogens are MOST LIKELY causing these skin, buccal, and tongue lesions?
Skin and buccal lesions are caused by HHV-8 (Kaposi’s sarcoma)
Tongue lesion is caused by EBv (hairy leukoplakia)
How does B19 infection present in a child w/ underlying hemolytic anemia (i.e. sickle-cell anemia or beta-thalassemia)
-Acute flu-like symptoms
-joint pain
-facial rash and skin rash with central clearing
accompanied by
-shortness of breath
-malaise
-confusion
-fatigue
(T/F) The MMR vaccine can be administered to immunosuppressed individuals and pregnant women to protect them from measles
False
What best explains why B19 virus replicates in erythroid precursor cells?
They express P antigen and are rapidly dividing
B19 does not possess the necessary factors to force host cell into S phase - needs a rapidly dividing cell to replicate all of its DNA
CMV is what herpes virus?
HHV-5
EBv is what herpes virus?
HHV-4
Owl-eye cells seen in CMV (HHV-5) infection
CMV infected cells are greatly enlarged, contain basophilic, intranuclear inclusions with clear rings around them and are often fused (called cytomegalic or “owls eye” cells)
A. Reactivation of latent CMV infection
There is a topical genciclovir application
Can also be a primary infection, but most adults have already been infected and have latent CMV (~70% of adults)
B. Acute flu-like sxs, joint pain, rash, accompanied by SOB, malaise, confusion, and fatigue
A = Pt’s infected w/ B19 with concurrent immunosuppression (rash and other sxs are mediated by immune complexes)
D = Pt’s w/ that are othersie healthy
B. HHV-6 (Roseola)
E. Malaria
C. Violet colored macular rash
B. Parvovirus B19
B. Anti-B19 IgG
E. Dengue virus
What can occur when someone who contracts a subsequent infection w/ Dengue virus of a different serotype than their original infection?
Hemorraghic fever
D. Acute biphasic illness starting w/ flu-like sxs followed by joint swelling, a red rash on the cheeks, and skin rash w/ central clearing
A. Myc
Heterophile Ab
Monospot tests for heterophil Abs (nonspecific Ab in response to EBv - agglutinates RBCs)
What viral infection can cause polyclonal B cell proliferation
EBv
C. TNF-𝛂
