Module 10.0 - HIV/AIDS and Opportunistic Infections Among Older Adults

Question 1

What type of cells does HIV target?

Answer 1

HIV targets dendritic cells, macrophages and CD4+ T cells

Question 2

What are the 6 phases of the HIV life cycle?

Answer 2

1. Entry (binding of HIV to receptors on the surface of the CD4 cell)

2. Reverse transcription (converts its RNA into DNA)

3. Integration (uses the enzyme integrase to insert its viral DNA into the DNA of the host CD4 cell)

4. Replication (HIV preferentially replicates in activated cells)

5. Assembly (the new viral proteins and enzymes move to the cell’s out membrane where they assemble into an immature, noninfectious HIV particle and bud)

6. Budding and maturation (the virus bud is released from the host CD4 cell). These steps are the basis for antiretroviral agents used in treating HIV.

Question 3

What are the symptoms of an acute HIV infection?

Answer 3

• Usual time from HIV exposure to development of symptoms is 2-4 weeks
• Symptoms include flu-like illness with fever, chills, fatigue, erythematous rash; serologic tests for HIV may be negative, indeterminate or positive at this time, although HIV viral load measures are elevated
• If the initial test is negative, re-test in 1-2 months

Question 4

What are the symptoms of a latent HIV infection?

Answer 4

‘asymptomatic’ phase, may have:

• generalized lymphadenopathy;
• positive (+) enzyme-linked immunoassay (ELISA) and Western blot for HIV infection;
• variable viral load and CD4 T lymphocyte count

Question 5

What are the symptoms of symptomatic HIV?

Answer 5

• fever, chills, diarrhea, weight loss; declining CD4 T cell count and increasing HIV viral load
• may develop shingles (herpes zoster)
• oral/vaginal candidiasis or frequent bacterial infections

Question 6

How is the diagnoses of AIDs given?

Answer 6

• Appearance of opportunistic infection, such as Pneumocystis jiroveci, Cryptosporidiumparvumor Candida albicans +CD4 T cell count < 500/mcl
• Diagnosis of AIDS without one of the above opportunistic infections is made if the CD4 T cell count is below 200/mcl)

Question 7

What are the symptoms associated with an advanced HIV infection?

Answer 7

• wasting, periodic fevers, fatigue, single or multiple opportunistic infections may occur
• CD4 T cell count < 50/mcl
• prognosis poor

Question 8

Describe the serologic testing used to diagnose an HIV infection

Answer 8

The preferred testing algorithm uses a fourth generation antigen/antibody combination HIV – 1/2 immunoassay plus a combination HIV -1/ HIV -2 antibody differentiation immunoassay (see algorithm below)

• If the 4th generation combination assay is negative (-), the person is considered HIV –Uninfected and no further testing is performed.
• If the 4 th generation combination assay is positive (+), an HIV -1/HIV -2 antibody differentiation immunoassay is performed. This test confirms the combination assay and identifies if the person is infected with HIV- 1, HIV -2, or both viruses.
• A plasma HIV RNA level is obtained to evaluate for acute infection if both the 4th generation assay and the confirmatory HIV-1/HIV -2 antibody differentiation immunoassay is indeterminate or negative (-).

Question 9

When should patients with HIV begin ART (Antiretroviral therapy)?

Answer 9

• All patients with HIV should be offered ART, including asymptomatic individuals, regardless of their immune status.
• The goal of ART is maximum suppression of HIV RNA.

Question 10

What are the 4 classes of antiretroviral therapy (ART)?

Answer 10

1. Nucleoside (and nucleotide) reverse transcriptase inhibitors (NRTIs) – considered the ‘backbone’ of antiretroviral therapy; usually given in pairs; these work during ‘reverse transcription’ phase of HIV replication
2. Non-nucleoside reverse transcriptase inhibitors (NNRTIs) – typically administered with an NRTI combination; these also work during ‘reverse transcription’ phase of HIV replication
3. Protease inhibitors (PIs) – these work in the ‘budding and maturation’ phase of HIV replication
4. Integrase strand transfer inhibitors (INSTIs) – these work in the ‘integration’ phase of HIV replication

Question 11

What is the goal for patients with ART?

Answer 11

• CD4+ cell count and HIV viral load determination 4-6 weeks after initiation and every 3-6 month thereafter until viral load is undetectable.
• Once viral load is suppressed, the CD4+ lymphocyte count need only be checked if the viral load becomes elevated again.
• Elderly patients should have monthly eGFR, creatinine and** **BUN to assure altered renal function is not occurring due to NRTIs.

Question 12

What opportunistic infections are common with an HIV infection?

Answer 12

A. Tuberculosis- based on positive screening test

B. Pneumocystic jiroveci (formerly P.carinii) – based on rapidly decreasing CD4+ cell count or an absolute CD4+cell count < 200 cells/mcl; expresses itself in up to 80% of AIDs cases

C. Toxoplasmosis- based on CD4+ count < 100cells/mcl and positive immunoglobulin G (Ig) serology; most common cause of neurological complications in HIV/AIDS

D. Mycobacterium avium – based on CD4+ cell count < 50 cells/mcl

E. Other opportunistic infections, including Histoplasmosis, Coccidioidmycosis, Pencilliosis).

Question 13

What vaccinations are recommended for HIV patients?

Answer 13

A. Hepatitis B- if found to be anti-hepatitis B core antigen negative

B. Inactivated influenza vaccine (*Live attenuated influenza vaccine is contraindicated in HIV- infected patients)

C. Hepatitis A vaccine

D. Pneumococcal vaccine

E. Tdap vaccine- one time administration as adult instead of Td.

F. Varicella zoster virus vaccination- should be considered for all elderly patients whose CD4+ lymphocyte counts are > 200 cells/mcl