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Flashcards in Virology (HIV) Deck (34):
1

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

2

Reverese trancriptase

define role in HIV

  • synthesis dsDNA from RNA
  • dsDNA incorporates into host genome

3

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 

4

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

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

5

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

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

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

7

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.

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

increase

9

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)

 

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

 

C. albicans (causes oral thrush and esophagitis)

11

define the pathogen

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

EBV

12

define the pathogen

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

Bartonella henselase (causes bacillary angiomatosis)

13

define the pathogen

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

Cryptosporiidium spp.

14

define the pathogen

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

Toxoplasma gondii

15

define the pathogen

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

Directly associated with HIV

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

JC virus reactivation (cause of PML) 

Polyomaviridae virus

dsDNA, naked, isohedrical

17

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

18

define the pathogen

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

CMV

19

define the pathogen

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

Maybe assoc w/ EBV

20

define the pathogen

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

Often assoc w/EBV

21

define the pathogen

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

HPV

non enveloped, dsDNA ,circular

22

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

23

define the pathogen

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

CMV

Herpesvirus enveloped dsDna linear

24

Define the pathogen

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

Aspergillus fumigatus

25

define the pathogen

  • clinical presentation:  pneumocystis pneumonia
  • Findings:  especially w/CD4+ <200 c/mm3 ground glass appearacne on imaging

Pneumocystis jirovecii

26

define the pathogen

  • clinical presentation:  Pneumonia
  • Findings:  Generally w/CD4+ >200 c/mm3

S. pneumoiniae

27

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)

28

What pathogens are assoc with HIV 

systemic presentation

histoplasma capsulatum

29

What pathogens are assoc with HIV 

Dermatologic

 

C. albicans

EBV

Bartonella henselae

30

What pathogens are assoc with HIV 

GI

Cryptosporidium spp

31

What pathogens are assoc with HIV 

Neurologic

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

32

What pathogens are assoc with HIV 

Oncologic

EBV, HPV, HHV-8

33

What pathogens are assoc with HIV 

Respiratory

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

34

prion disease

  • MOA
  • resisits degradation by what
  • accumulation of PrPsc can 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 PrPsc which is transmissible
  • accumulation:  spongiform encephalophathy, dementia, ataxia and death!
  • Spradic
    • RP:  Creutzfeldt jakob disease
    • I:  Gerstmann-staussler-scheinker syndrome
    • A: kuru