Virology (HIV)

Question 1

what are the 3 structural genes in HIV

define function

Answer 1

• 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

Question 2

Reverese trancriptase

define role in HIV

Answer 2

• synthesis dsDNA from RNA
• dsDNA incorporates into host genome

Question 3

HIV virus binds to what on Tcells and Macrophages

Answer 3

• T cells
  
  • CCR5 (early) and CXCR4 (late) co-receptor and CD4 on Tcell
• Macrophages
  
  • CCR5 and CD4

Question 4

define the type of mutation that causes slow infection of HIV and immunity against HIV.

Answer 4

• Heterozygous CCR5 mutation
  
  • slow course
• Homozygous CCR5 mutation
  
  • immunity

Question 5

HIV diagnosis

• Test that is used to screen and confirm
• test that detemine viral load
• AIDS diagnosis
• HIV-+ w/AIDS defining condition

Answer 5

• 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

Question 6

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

Answer 6

Falsely positive initally in babies born to infected mothers (anti-gp120 crosses the pacenta)

Question 7

What are the fours stages of untreated infection of HIV

Where does the latent phase replicate?

Answer 7

• Fours stages
  
  • Flu like (acute)
  • Feeling fine (latent)
  • Falling count
  • Final crisis
• During latent phase, virus replicates in lymph nodes.

Question 8

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

Answer 8

increase

Question 9

define the pathogen

clinical presentation: low grade fevers, cough, hepatosplenomegaly, tongue ulcer

Findings: oval yeasts cells w.in macrophages, CD4+ <100 cell/,,3

Answer 9

Histoplasm capsulatum (causes only pulmonary symptoms in immunocompetent host)

Question 10

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}

Answer 10

C. albicans (causes oral thrush and esophagitis)

Question 11

define the pathogen

• clinical presentation: hairy leukoplakia
• Findings: often on lateral tongue

Answer 11

EBV

Question 12

define the pathogen

• clinical presentation: superficial vascular proliferation
• Findings: biopsy reveals neuotrophilic inflammation

Answer 12

Bartonella henselase (causes bacillary angiomatosis)

Question 13

define the pathogen

• clinical presentation: Chronic, watery, diarrhea
• Findings: Acid-fast cysts seen in stool especially when CD4+ <200 c/mm3

Answer 13

Cryptosporiidium spp.

Question 14

define the pathogen

• clinical presentation: abscesses
• Findings: Many ring-enhancings lesions on imaging, CD4+ < 100 cels/mm3

Answer 14

Toxoplasma gondii

Question 15

define the pathogen

• clinical presentation: Dementia
• Findings: Must differentiate from other causes

Answer 15

Directly associated with HIV

Question 16

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

Answer 16

JC virus reactivation (cause of PML)

• Polyomaviridae virus*
• dsDNA, naked, isohedrical*

Question 17

define the pathogen

• clinical presentation: meningitis
• Findings: india ink stain reveals yeast with narrow based budding and large capsule, CD4+ <5- c/mm3

Answer 17

Crytococcus neoformans

Question 18

define the pathogen

• clinical presentation: retinitis
• Findings: cotton-wool spots, on fundoscopic exam and may also occur w/esophagitis, CD4+ <50 cells/mm3

Answer 18

CMV

Question 19

define the pathogen

• clinical presentation: Non-hodgkin lymphoma (lg cell type)
• Findings: often on oropharynx (Waldeyer ring)

Answer 19

Maybe assoc w/ EBV

Question 20

define the pathogen

• clinical presentation: Primary CNS lymphoma
• Findings: Focal or multiple, differentiate from toxoplasmosis

Answer 20

Often assoc w/EBV

Question 21

define the pathogen

• clinical presentation: SCC
• Findings: Often in anus (men who have sex w/men)

Answer 21

HPV

non enveloped, dsDNA ,circular

Question 22

define the pathogen

clinical presentation: superficial neoplastic prolifetaion of vasculature

Findings: Biopsy reveals lymphocytic inflammation

Answer 22

HHV-8 (causes Kaposi sarcoma) do not confuse w/bacilary angiomatosis caused by B. henselae.

Herpesvirsu, enveloped, DS linear

Question 23

define the pathogen

• clinical presentation: Intestitial pneumonia
• Findings: biopsy reveals cells w/intranuclear (owl eye) inclusion bodies

Answer 23

CMV

Herpesvirus enveloped dsDna linear

Question 24

Define the pathogen

• Clinical presentation: invasive aspergiolosis
• Findings: pleuritic pain, hemoptysis, infiltrates on imaging

Answer 24

Aspergillus fumigatus

Question 25

# define the pathogen * clinical presentation: pneumocystis pneumonia * Findings: especially w/CD4+ \<200 c/mm3 ground glass appearacne on imaging

Answer 25

*Pneumocystis jirovecii*

Question 26

# define the pathogen * clinical presentation: Pneumonia * Findings: Generally w/CD4+ \>200 c/mm3

Answer 26

S. pneumoiniae

Question 27

# define the pathogen * clinical presentation: tuberculosis like disease * Findings: especially w/CD4+ \<50 c/mm3

Answer 27

*Mycobacterium avium-intracellulare* also know as Mycobacterium avium complex (MAC)

Question 28

What pathogens are assoc with HIV systemic presentation

Answer 28

*histoplasma capsulatum*

Question 29

What pathogens are assoc with HIV Dermatologic

Answer 29

C. albicans EBV Bartonella henselae

Question 30

What pathogens are assoc with HIV GI

Answer 30

*Cryptosporidium spp*

Question 31

What pathogens are assoc with HIV Neurologic

Answer 31

* *Toxoplasma gondii* * JC virus (cause of PML) * *Cryptococcus neoformans* * CMV

Question 32

What pathogens are assoc with HIV Oncologic

Answer 32

EBV, HPV, HHV-8

Question 33

What pathogens are assoc with HIV Respiratory

Answer 33

* CMV * *Aspergillus fumigatus* * *Pneumocytis jirovecii* * *S. pneumoniae* * *MAC (mycobacterium avium intracellulare*

Question 34

prion disease * MOA * resisits degradation by what * accumulation of PrP^sc can cause what * what are the sporadic disease * rapidly progressive * inherited * Acquired

Answer 34

* prior disease are caused by the conversion of a normal (predominalty alpha-helical) protein termed prior protein PrPR c to a B-pleated form PrP^sc which is transmissible * accumulation: spongiform encephalophathy, dementia, ataxia and death! * Spradic * RP: Creutzfeldt jakob disease * I: Gerstmann-staussler-scheinker syndrome * A: kuru