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Flashcards in Pathogenesis of AIDS Deck (50)
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0

Stage 0

early infection
recognized by HIV-test within 180 days of the first HIV+ test
meaning test positive within 180 days of the last negative test

1

HIV infection stage is based on

age specifc CD4+ T cell count
CD4 T cell % of total Lymphocytes

2

stage 1

No AIDS-defining condition and a CD4 cell count at or above the cells/ul indicated per age

3

stage 2

No AIDS defining condition and a CD4 cell count at or above the cells/ul indicated per age

4

stage 3

AIDS
documented AIDS defining condition or CD4 cell count less than 200, 500 or 750 cells/ul indicated per age

5

Stage unknown

lab confirmation of HIv infection but no information on Cd4 cell count, CD4 cell percentage, or the presence of an AIDS-defining condition

6

Staging can be bidirectional given ....

no AIDS defining condition is present

7

AIDS defining illness in children under 6

Bacterial infections, multiple or recurrent

8

AIDS defining illnesses in adults, adolescents or children over 6yo

cervical cancer, invasive
Mycobacterium TB of any site, pulmonary
Pneumonia, recurrent

9

Phases of HIV infection

1. Acute retroviral syndrome - weeks
2. Chronic HIV - years to decades
3. AIDS - Months to years

10

Acute retroviral syndrome

primary infection of cells in blood and mucosa
infection is then established in lymphoid tissues leading to viremia
Acute HIV syndrome when spread of infection throughout body
seroconversion - Anti HIV antibodies and HIV specific CTLs
Immune response

11

Chronic HIV

Clinical latency
establishment of chronic infection
virus trapped in lymphoid tissues by follicular DCs, low level of viral production
other microbial infections or cytokines can lead to increased viral replication

12

AIDS - phase

destruction of lymphoid tissue
depletion of CD4 T cells

13

Constitutional symptoms of ARS

fever*
chills*
fatigue*
Night sweats, anorexia and wt loss

14

Lymphatic symptoms of ARS

*Swollen lymph nodes especially in groin, head and neck

15

Nose and throat symptoms of ARS

*Sore throat, with or without ulcers or thrush

16

GI symptoms of ARS

Nausea
emesis
diarrhea

17

Musculoskeletal symptoms of ARS

Asymmetric joint swelling and tenderness
*myalgias

18

Neurologic symptoms of ARS

personality changes, headache, and painful, stiff neck

19

Rash characteristics of ARS

Maculopapular and primarily on trunk and/or proximal extremities

20

characteristics of oral lesions in ARS

thrush develops commonly on soft palate
early lesions also seen along gingival border

21

Reactivation in ARS

can reactivate HSV - cold sores
or VSZ - shingles

22

How can HIV enter the body?

blood
colon-rectum
vagina

23

What happens when HIV initially enters?

infects macrophages

24

How does HIV affect macrophages?

creates virus reservoir
infects the microglial cells of the brain, Pulmonary alveolar macs and Dendritic cells in skin
Causes macrophage dysfunction, virus release and cytokine release and dysregulation of immune function

25

Where do HIV travel for its latent period?

Lymph nodes

26

What happens upon increased viral load in the blood with regards to immunopathogenesis?

by this time, HIV has been able to infect CD4 T cells
if crosses the BBB leads to AIDS dementia
through CD4 ctyloysis causes
-immunodeficiency
-loss of B cell control - lymphadenopathy, hypergammaglobulinemia
-Loss of DTH (delayed type hypersensitivity) function - cutaneous infection and intracellular pathogens

27

what happens as a result of loss of T cell function?

severe systemic opportunistic infections
Kaposi's sarcoma
Lymphoma

28

HIV causes ??? and what are the outcomes

-Lytic and latent infection of CD4 T cells
-Persistent infection of cells of macrophage family
-Disrupts neuron function
Outcomes are:
Immunodeficiency, AIDS dementia (crosses the BBB)

29

Briefly describe progression of untreated HIV

About 6 weeks after primary infection, CD4 T cell count falls drastically. At this same time, viral load peaks. This is acute HIV syndrome and there is wide dissemination of virus and seeding of lymphoid organs
small T cell count recovery around 12 weeks as viral load drop while virus enters latent period
over next 10-11 years, viral load slowly increases as CD4 count continues to slowly decrease
Constitutional symptoms appear 7-8 years
opportunistic infections occur as viral load increases exponentially
Death by year 10 -11