Clinical features of AIDS

Question 1

what causes the immune dysfunction in HIV infection?

Answer 1

-loss of functional CD4 lymphocytes-> loss of memory CD4 cells, and inability to modulate new cell-mediated and antibody-mediated immune response

Question 2

what happens with CD8 cells in HIV infection?

Answer 2

eventual loss of CD8 cytotoxic cells and ability to mount T cell mediated responses against opportunistic infections

Question 3

what happens with B cells in HIV infection?

Answer 3

polyclonal activation (non-antibody specific) of B cells with inability to mount new antibody responses

Question 4

diagnosis of infection

Answer 4

based on demonstrating antibody to multiple HIV antigens: gp120/160 + gp41 or P24

• must have BOTH, one + one
• shown on western blot

Question 5

what is the sensitivity and specificity of HIV testing?

Answer 5

HIV serology + WB-> >99%

Question 6

why can’t test for seroconversion in HIV?

Answer 6

may not take place for 6-12 weeks

Question 7

what is the “gold standard” for diagnose and monitor HIV infection?

Answer 7

HIV RNA level

• follow effectiveness of therapy
• indicated breakthrough of virus
• predicts diagnosis in combination with CD4 levels

Question 8

what is a full blown AIDS CD4 count level?

Answer 8

below 200/ml

-long lasting fever, fatigue, weight loss, diarrhea

Question 9

what is the strongest indicator or disease progression?

Answer 9

CD4 count

Question 10

in HIV infection, what do the lymphoid tissue show?

Answer 10

loss of T-cells (particularly peyer’s patches) and expansion of B cell area (b/c of polyclonal acitvation) and generalized lymphadenopathy

Question 11

what is found in the follicular mantle cells in early infection?

Answer 11

marked follicular hyperplasia, viral particles

Question 12

in later stages, what to the lymph nodes show signs of?

Answer 12

“burn out” pattern: loss of most lymphoid elements

• chronic inflammation leads to cell loss, fibrosis
• infected tissue may show formation of lymphocyte syncytial (giant cells) with the X4 type of virus

Question 13

what is infection of the CNS associated with?

Answer 13

subacute meningoencephalitis with chronic inflammatory infiltrate with microglial nodules and multinucleated giant cells

Question 14

what are some complications to HIV?

Answer 14

Kaposi’s sacroma (proliferating mesenchymal spindle cells that form blood vessels) and AIDS associated B cell lymphomas

Question 15

what are two IMPORTANT facts with the pathology of those with AIDS?

Answer 15

1. ) infections in patients with AIDS don’t present in typical manner, present in atypical manner with fewer symptoms
2. )serology not helpful in diagnosing-> unable to mount an antibody response

Question 16

what can present at time of transmission?

Answer 16

constitutional symptoms-> fever, malaise, rash

Question 17

what is acute retroviral syndrome?

Answer 17

high levels of viral replication, viremia, widespread seeding of lymphoid tissue (controlled by host antiviral immune response)

Question 18

when are antibodies not yet detectable?

Answer 18

seroconversion may not take place for 6-12 weeks, “window

when antibodies not detectable

Question 19

what do initial drop in viral titers correspond with?

Answer 19

development of specific anti-HIV cell mediated immunity

Question 20

a patient can remain well during what period?

Answer 20

period in which his/her immune function undergoes slow deterioration with gradual loss of CD4 cells and immune dysregulation
(can last several years)

Question 21

what is a predictor of progression of the disease?

Answer 21

level of steady state viremia

Question 22

what do concurrent infection appear to do with this disease?

Answer 22

accelerate the disease process by activating the immune system and causing increased proliferation of virus

Question 23

what do patients suffer from with HIV infection of microglial cells?

Answer 23

CNS dementia

-virus carried to brain by infected macrophages

Question 24

associated neoplastic conditions?

Answer 24

Kaposi’s sarcoma, Hodgkin’s disease and lymphoma

Question 25

Opportunistic infections with HIV?

Answer 25

Candidiasis
Pneumocytis
Cryptococcus
GI infection: Giardia, entamoeba, cryptosporidiosis 
Mycobacterium avium, 
Pneumocystis j.
CVM

Question 26

what can give overwhelming viral infections?

Answer 26

CMV, herpes zoster

Question 27

reactivation of latent infections?

Answer 27

toxoplasmosis, TB, herpes zoster

Question 28

AIDS associated cancers

Answer 28

Kaposi’s sarcoma
non-Hodgkin’s lymphoma
invasive carcinoma of uterine cervix (assoc. HPV)

Question 29

Kaposi’s sarcoma

Answer 29

• more common in homosexual/bisexual males
• associated with HHV8 infection
• more aggressive than other cancers
• involves skin, mucous membranes, GI tract
• proliferation of endothelial cells, smooth muscle cells, pericytes
• inefficient vascular formation with blood-filled channels

Question 30

non-Hodgkin’s lymphoma

Answer 30

highly aggressive
B cell origin, polyclonal B cell activation
extra nodal sites, brain
EBV in 30%

Question 31

what causes the lack of immune response in this disease?

Answer 31

1. immune exhaustion
2. lack of T helper cells
3. immune escape by virus
4. host genetic factors

Question 32

what is the problem with virus specific antibodies

Answer 32

how to promote anti-viral response in people without the destruction of HIV-specific CD4 cells in the process

Question 33

what is the major focus of HIV eradication and therapy?

Answer 33

prevention

HAART minimizes viral load but does not eliminate the virus

Question 34

what kind of vaccine might be helpful more than antibody mediated responses?

Answer 34

vaccines that stimulate cell-mediated responses

Question 35

complications to HAART therapy?

Answer 35

lipoatrophy, lipoaccumulation, elevated lipids
insulin resistance
peripheral neuropathy
premature cardiovascular disease
renal, hepatic dysfunction