HIV Pathogenesis & Therapy

What are the specific laboratory tests used to identify and diagnose HIV?

• HIV Tests

  • Antibody test → detects up to 12 wks post exposure but have to wait longer to take (3 wks)

  • 4th gen test (abs + antigens) → detects up to 6 wks post exposure

  • Nucleic acid test (NATs) → detects up to 1 mo post exposure but only have to wait 1 wk 

• Specific labs: 

  • CD4 count → detects extent of immune damage (goal = >500)

  • Plasma viral load (goal = undetectable)

Explain the difference between HIV and AIDS

HIV stands for Human Immunodeficiency Virus.
It’s a virus that attacks the body’s immune system, specifically the CD4 cells (T cells), which help the body fight infections.

• A person with HIV can look and feel healthy for many years.

• HIV can be controlled with medicine (called antiretroviral therapy or ART), so people can live long, healthy lives.

AIDS stands for Acquired Immunodeficiency Syndrome.
It is the last and most serious stage of HIV.

• AIDS happens if HIV is not treated.

• Requires CD4<200 or hx of AIDS defining illness (basically any other condition that stemmed from HIV infx because immune system very weak)

  
  

Evaluate route of transmission of HIV

• 🔴Highest Risk

  • Mother to baby (no medicine) – 24%

  • Receptive anal sex – 0.3% to 3%

  • Sharing needles – 0.67%

  • Needlestick injury (blood exposure) – 0.3%

  🟠 Moderate Risk

  • Receptive vaginal sex – 0.1% to 0.2%

  • Insertive vaginal sex – 0.03% to 0.14%

  • Blood to mucous membranes (like eyes or mouth) – 0.09%

  🟡 Lower Risk

  • Insertive anal sex – 0.06%

  • Receptive oral sex (male) – 0.06%

  • Female-female oral contact – Very rare (only 4 known cases)

Explain the mechanism of action of antiretroviral medications and how they affect the HIV lifecycle

NNRTIs- Reverse transcription inhibitors
NRTIs- Reverse transcription inhibitors
Integrase inhibitors- inhibit virus integration
Protease inhibitors- inhibits budding (turning immature virus into mature infectious virus)
CIs- Breaks down capsid that holds in virus DNA

What are the pre-treatment tests needed prior to ARV initiation?

• HIV test

• CD4 count

• Plasma viral load (RNA)

• CBC

• chem panel

• BUN, SCr

• Glucose/A1C

• Lipid panel

• Liver function

• Urinalysis (if starting tenofovir)

• Hep A/B/C, Syphilis, toxoplasma gondii IgG, TB

Identify the classes of antiretroviral drugs

NRTIs (nucleo reverse transcriptase inhibitors)
NNRTIs (nonnuclo reverse transcriptase inhibitors)
PIs (protease inhibitors)
EIs (entry inhibitors)
INSTIs (integrase inhibitors)
CIs (capsid inhibitors)

NRTI drugs

• All, Elephants, Love, Tacos 

  • Abacavir

  • Emtricitabine

  • Lamivudine

  • Tenofovir DF

  • Tenofovir AF

NNRTI drugs

• Never, Eat, Really, Dry, Eggs

  • Nevirapine

  • Etravirine

  • Rilpivirine

  • Doravirine

  • Efavirenz

Protease inhibitor drugs

• Darunavir

• Darunavir + Cobicistat
  Ritonavir

EIs (entry inhibitors)

~ Every, Monkey, Fights, Infection

Enfuvirtide

Maraviroc

Fostemsavir

Ibalizumab

INSTIs (integrase inhibitors)

-gravirs

CIs (capsid inhibitors):

• Lenacapavir (adjunct only)

• Cobicistat (boosting agent only NO antiviral activity)

What are the common NRTI combinations and associated brand names?

• Abacavir + Lamivudine (Epzicom)

• Emtricitabine + Tenofovir

  • DF (Truvada)

  • AF (Descovy)

What is the difference between tenofovir DF and AF formulation?

AF has higher bioavailability than DF → lower dose necessary

What are the combination ARVs for HIV therapy including brand names?

When should treatment be initiated in HIV positive patients?

• hx of AIDS illness

• pregnant

• HIV nephropathy

• hep b/c coinfection

• any CD4 count 

everyone!

What are the first line treatment initiation options?

Second line treatment options

Pregnancy treatment options