HIV and Retroviral Infections

Question 0

What does HTLV stand for?

Answer 0

Human T Lymphocyte Virus

Question 1

What is the unique feature of the Retroviridae family? and What does it mean?

Answer 1

Retro=Backward; viruses have reverse transcriptase that allows them to make DNA from RNA

Question 2

What do 3rd generation assays for HIV antibody testing detect?

Answer 2

detect HIV 1 and HIV 2 antibodies

Question 3

How are results reported in 3rd and 4th generation assays?

Answer 3

As positive or negative; does not differentiate between HIV 1 and HIV 2

Question 4

In EIA HIV testing, what do you do if you have a positive results vs a negative result?

Answer 4

If negative-STOP and report negative
If positive- retest by EIA in duplicate, then if both retests are negative report them and if either is positive report as positive and do confirmatory test.

Question 5

What are sources of error in EIA testing?

Answer 5

Technical: splashing, improper rinsing, dirty glassware
Biological: cross-reacting antibodies, antibodies against tissue antigens from culture lysates, antibodies against vectors used to express cloned antigens

Question 6

How is a Western Blot performed?

Answer 6

Ag suspension applied to top margin of electrophoresis chamber containing polyacrylamide gel and SDS; electrical current applied causing Ag to migrate; nitrocellulose sheet positioned directly on surface of gel that contains bands and electrical current is applied to transfer or “blot” the bands from the gel to the sheet; paper dried and cut into strips; individual strips used as Ag substrates to react patient serum with paper

Question 7

Describe Immunoblotting

Answer 7

nitrocellulose strip w/ Western blotted Ag are reacted with patient Ab, incubated and rinsed, enzyme-labeled antispecies globulin is added, incubated, and rinsed; substrate added and color development is visible in areas of Ab binding (bands visible), no color if nothing for Ab to bind to

Question 8

What is the CDC criteria for defining an HIV 1 ab positive immunoblot

Answer 8

at least 2 of 3 critical bands must be present: 120/160, 40, or 24

Question 9

We can monitor known HIV 1 positive patients with ______ ______ testing

Answer 9

nucleic acid

Question 10

Positive HIV1/2 are confirmed with what test?

Answer 10

Multispot

Question 11

If multispot confirmation is negative or indeterminant what do you do?

Answer 11

test for HIV1 nucleic acid

Question 12

If nucleic acid test is positive what do you do?

Answer 12

monitor viral load

Question 13

If nucleic acid test is negative what do you do?

Answer 13

suspect initial false positive screening test and repeat in 2-6 weeks if risk factors present

Question 14

____ is detectable earlier in infection than both HIV 1 Ag and antibody, and circulates during entire course of infection

Answer 14

RNA

Question 15

Effective treatment of antiviral therapy may ______ the RNA levels

Answer 15

decrease

Question 16

if antiviral therapy losses effectiveness, nucleic acid levels will ______

Answer 16

increase

Question 17

______ is the most important AIDS indicator infection

Answer 17

Pneumocystis jirovecii

Question 18

If a patient has AIDS indicator infections and no other cause for immunosuppression and HIV infection cannot be confirmed in the lab can a diagnosis of AIDS be made?

Answer 18

YES

Question 19

Can lab data alone diagnose AIDS?

Answer 19

NO, patient must be experiencing AIDS indicator infections in order to have AIDS