HIV/TB PBL

Question 1

Efavirenz

Answer 1

NNRTI

Question 2

Raltegravir

Answer 2

integrase inhibitor

inhibits HIV integrase

Question 3

Emtricitabine

Answer 3

NRTI

requires phosphorylation for activation

Question 4

Enfuviritide

Answer 4

fusion inhibitor

binds gp41

Question 5

-navir

Answer 5

protease inhibitors

ritonavir used for boosting

Question 6

Tenofovir

Answer 6

NRTI (only nucleotide–others are nucleosides)

does not require phosphorylation for activation

Question 7

Nevirapine

Answer 7

NNRTI

Question 8

Delavirdine

Answer 8

NNRTI

Question 9

Ritonavir

Answer 9

protease inhibitor

used in “ritonavir boosting”

inhibits CYP450, increasing activity of other protease inhibitors

Question 10

Abacavir

Answer 10

NRTI

requires phosphorylation for activation

Question 11

Maraviroc

Answer 11

fusion inhibitor

binds CCR5

Question 12

TB drug

inhibits DNA-dependent RNA polymerase

Answer 12

rifampin and rifabutin

Question 13

Rifampin PK side effect

Answer 13

increased activity of CYP450

Question 14

TB drug

decreases synthesis of mycolic acids

Answer 14

isoniazid

must be activated by catalase-peroxidase (KatG gene) to convert to active metabolite

Question 15

TB drug

mechanism unknown

Answer 15

pyrazinamide

Question 16

Decreases polymerization of carbohydrates by blocking arabinosyltransferase

Answer 16

ethambutol

Question 17

Pyridoxine use in TB

Answer 17

vitamin B₆

used in conjunction with isoniazid

prevents neurotoxicity when using isoniazid

Question 18

Cytokine that makes angry macrophages

Answer 18

IFN-γ

secreted by Th₁ CD4+ T-cells

Question 19

Cytokine that differentiates CD4+ cells into Th₁ cells

Answer 19

IL-12

Question 20

Mycolic acid activates which TLR

Answer 20

TLR-2

Question 21

How does the

interferon-γ release assay

work

Answer 21

antigens ESAT and CFP-10 added to whole blood

antigens taken up by macrophages

present to memory Th₁ cells if present

memory Th₁ reactivation

IFN-γ release

⇒ + assay if memory Th₁ cells present

Question 22

Walling off of granulomas

Answer 22

TNF-α secreted by M1 macrophages recruits leukocytes to wall off granuloma

(around outside of granuloma)

Question 23

TB cord factor

Answer 23

virulence factor

prevents fusion between phagocytic vesciles and lysosomes

Question 24

gp120 binds

Answer 24

CD4

Question 25

gp41 binds

Answer 25

CCR5 (early infection) CXCR4 (late infection)

Question 26

HIV binding to CD4+ T-cells mechanism

Answer 26

gp120 bind CD4 gp41 binds CCR5 (CXCR4 later) fusion

Question 27

**Rifampin** MOA TU Tox

Answer 27

**_MOA:_** inhibits DNA-dependent RNA-polymerase **_TU:_** TB **_Tox:_** increased P450s, orange body fluids, Rifabutin favored in HIV patients because less P450 ramping up

Question 28

**Isoniazid** MOA TU Tox

Answer 28

**_MOA:_** inhibits formation of mycolic acids, bacterial catalase-peroxidase encoded by KatG needed to convert INH to active metabolite **_TU:_** TB, solo agent for prophylaxis **_Tox:_** neurotoxicity, hepatotoxicity. pyridoxine (B6) used to prevent neurotoxicity, lupus

Question 29

**Pyrazinamide** MOA Tox

Answer 29

**_MOA:_** unknown **_Tox:_** hyperuricemia, hepatotoxicity

Question 30

**Ethambutol** MOA TU Tox

Answer 30

**_MOA:_** decreased carbohydrate polymerization of mycobacterium cell wall by blocking arabinosyltransferase **_TU:_** TB **_Tox:_** optic neuropathy (red-green colorblindness)