Virology (HIV) Flashcards
what are the 3 structural genes in HIV
define function
-
env (gp120 & gp41)
- Formed from cleaveage of gp160 to form envelope glycoproteins
- gp120 attachment to host CD4+ T cell
- gp 41 fusion and entry
-
gag (p24)
- capsid protein
-
pol
- reverse transcriptase,aspartate protease, integrase
Reverese trancriptase
define role in HIV
- synthesis dsDNA from RNA
- dsDNA incorporates into host genome
HIV virus binds to what on Tcells and Macrophages
- T cells
- CCR5 (early) and CXCR4 (late) co-receptor and CD4 on Tcell
- Macrophages
- CCR5 and CD4
define the type of mutation that causes slow infection of HIV and immunity against HIV.
- Heterozygous CCR5 mutation
- slow course
- Homozygous CCR5 mutation
- immunity
HIV diagnosis
- Test that is used to screen and confirm
- test that detemine viral load
- AIDS diagnosis
- HIV-+ w/AIDS defining condition
- Tests
- screenings: ELIZA
- confirmatory: Western blot
- Viral load test
- HIV PCR/viral load tests determine the amt of viral RNA in the plasma
- High viral load assoc w/poor prognosis
- Also use viral load to monitor effect of drug therapy
- AIDS diagnosis <200 CD4+ cells/mm3 (norm: 500-15000)
- Pneumocysitis pneuomina or CD4 percentage <14
ELISA./westernblot tests look for antibodies to viral proteins; these tests often are falsely negative in the first 1-2 months of HIV infection
what happens to babies of infected moms
Falsely positive initally in babies born to infected mothers (anti-gp120 crosses the pacenta)
What are the fours stages of untreated infection of HIV
Where does the latent phase replicate?
- Fours stages
- Flu like (acute)
- Feeling fine (latent)
- Falling count
- Final crisis
- During latent phase, virus replicates in lymph nodes.
common disease of HIV-positive adults
As CD4+ count dec, risk of reactivation of past infections (TB, HSV, shingles), dismination of bacterial infeciton adn fungal infection (coccidioidmycosis) and non-hodgkin lymphomas
increase
define the pathogen
clinical presentation: low grade fevers, cough, hepatosplenomegaly, tongue ulcer
Findings: oval yeasts cells w.in macrophages, CD4+ <100 cell/,,3
Histoplasm capsulatum (causes only pulmonary symptoms in immunocompetent host)
define the pathogen
clinical presentation: fluffy white cottage cheese lesions
- Findings:
- pseudohyphae commonly oral if CD4+<400 c/mm3
- esophageal if CD4+ <100 c/mm3
C. albicans (causes oral thrush and esophagitis)
define the pathogen
- clinical presentation: hairy leukoplakia
- Findings: often on lateral tongue
EBV
define the pathogen
- clinical presentation: superficial vascular proliferation
- Findings: biopsy reveals neuotrophilic inflammation
Bartonella henselase (causes bacillary angiomatosis)
define the pathogen
- clinical presentation: Chronic, watery, diarrhea
- Findings: Acid-fast cysts seen in stool especially when CD4+ <200 c/mm3
Cryptosporiidium spp.
define the pathogen
- clinical presentation: abscesses
- Findings: Many ring-enhancings lesions on imaging, CD4+ < 100 cels/mm3
Toxoplasma gondii
define the pathogen
- clinical presentation: Dementia
- Findings: Must differentiate from other causes
Directly associated with HIV
define the pathogen
- clinical presentation: encephalopathy
- Findings: Due to reactive of a latent virus, results in demyelination, CD4+ <200 c/mm3
describe the morphology as well
JC virus reactivation (cause of PML)
- Polyomaviridae virus*
- dsDNA, naked, isohedrical*
define the pathogen
- clinical presentation: meningitis
- Findings: india ink stain reveals yeast with narrow based budding and large capsule, CD4+ <5- c/mm3
Crytococcus neoformans
define the pathogen
- clinical presentation: retinitis
- Findings: cotton-wool spots, on fundoscopic exam and may also occur w/esophagitis, CD4+ <50 cells/mm3
CMV
define the pathogen
- clinical presentation: Non-hodgkin lymphoma (lg cell type)
- Findings: often on oropharynx (Waldeyer ring)
Maybe assoc w/ EBV
define the pathogen
- clinical presentation: Primary CNS lymphoma
- Findings: Focal or multiple, differentiate from toxoplasmosis
Often assoc w/EBV
define the pathogen
- clinical presentation: SCC
- Findings: Often in anus (men who have sex w/men)
HPV
non enveloped, dsDNA ,circular
define the pathogen
clinical presentation: superficial neoplastic prolifetaion of vasculature
Findings: Biopsy reveals lymphocytic inflammation
HHV-8 (causes Kaposi sarcoma) do not confuse w/bacilary angiomatosis caused by B. henselae.
Herpesvirsu, enveloped, DS linear
define the pathogen
- clinical presentation: Intestitial pneumonia
- Findings: biopsy reveals cells w/intranuclear (owl eye) inclusion bodies
CMV
Herpesvirus enveloped dsDna linear
Define the pathogen
- Clinical presentation: invasive aspergiolosis
- Findings: pleuritic pain, hemoptysis, infiltrates on imaging
Aspergillus fumigatus
define the pathogen
- clinical presentation: pneumocystis pneumonia
- Findings: especially w/CD4+ <200 c/mm3 ground glass appearacne on imaging
Pneumocystis jirovecii
define the pathogen
- clinical presentation: Pneumonia
- Findings: Generally w/CD4+ >200 c/mm3
S. pneumoiniae
define the pathogen
- clinical presentation: tuberculosis like disease
- Findings: especially w/CD4+ <50 c/mm3
Mycobacterium avium-intracellulare
also know as Mycobacterium avium complex (MAC)
What pathogens are assoc with HIV
systemic presentation
histoplasma capsulatum
What pathogens are assoc with HIV
Dermatologic
C. albicans
EBV
Bartonella henselae
What pathogens are assoc with HIV
GI
Cryptosporidium spp
What pathogens are assoc with HIV
Neurologic
- Toxoplasma gondii
- JC virus (cause of PML)
- Cryptococcus neoformans
- CMV
What pathogens are assoc with HIV
Oncologic
EBV, HPV, HHV-8
What pathogens are assoc with HIV
Respiratory
- CMV
- Aspergillus fumigatus
- Pneumocytis jirovecii
- S. pneumoniae
- MAC (mycobacterium avium intracellulare
prion disease
- MOA
- resisits degradation by what
- accumulation of PrPsccan cause what
- what are the sporadic disease
- rapidly progressive
- inherited
- Acquired
- prior disease are caused by the conversion of a normal (predominalty alpha-helical) protein termed prior protein PrPR c to a B-pleated form PrPscwhich is transmissible
- accumulation: spongiform encephalophathy, dementia, ataxia and death!
- Spradic
- RP: Creutzfeldt jakob disease
- I: Gerstmann-staussler-scheinker syndrome
- A: kuru