HIV

Question 1

what does surface glycoprotein (gp120) bind to?

Answer 1

CD4 glycoprotein of the surface of host cells, leading to the progressive destruction of the CD4+ lymphocyte population.

Question 2

transmission of hiv…

Answer 2

HIV is spread by blood and body fluids and the modes of transmission are by sex (homosexual, heterosexual and oral), blood (injecting drug use, unscreened blood, blood products or body tissues and needlestick or other body fluid exposure) and mother-to-child (mainly perinatal but also in breast milk or less commonly earlier in pregnancy).

Question 3

The normal CD4 lymphocyte count is?

Answer 3

500-1500 cells/mm3

Question 4

patient is often asymptomatic from HIV infection until the count has fallen to…

Answer 4

<200 cells/mm3

Question 5

common sy and sx of his

Answer 5

weight loss, lymphadenopathy, thrush, skin and oral disease, flu-like, fever, pharyngitis

Question 6

What is Pneumocystis jiroveci pneumonia?

Answer 6

most common late stage AIDS infection, cd4 below 200 usually,
dry cough, breathlessness,
ix-cxr, sputum or bronchoscopy,
tx - cortrimoxazole, pentamidine until cd4>200.

Question 7

what are 3 infections which may be associated with aids patients? bacterial, viral and fungal types…

Answer 7

bacterial -TB
viral - HSV, CMV, EBV, HPV
fungal - pneumosystitis carnii, cryptococcus, aspergillus, candida
protozoal - toxoplasmosis, leishmaniasis

Question 8

What blood test abnormalities will be seen on HIV Ix?

Answer 8

increased viral load, reversed CD4:CD8 ratio, low CD4 count, thrombocytopenia, lymphopenia

Question 9

Ix for HIV

Answer 9

Bloods - HIV antigen combined with HIV antibody testing, then use viral load to measure the effectiveness of anti-retroviral therapy, low CD4 count and reversed cd4:dc8 ratio.
ELISA

Question 10

when should prophylaxis and antivirals be started?

Answer 10

Patients should be started on antivirals if CD4 count <350. Start PCP prophylaxis when count <200.

Question 11

what are the classes of Antiviral drugs used for HIV?

Answer 11

1st Line = Nucleoside reverse transcriptase inhibitors - Lamivudine, zidovudine (AZT), didanosine (ddI), zalcitabine (ddC), lamivudine (3TC), stavudine (d4T) and abacavir.
1st Line = Non-nucleoside reverse transcriptase inhibitors - Nevirapine.
2nd Line = Protease inhibitors - Ritonavir
Intergrase inhibitors

Question 12

se’s of antivirals?

Answer 12

marrow toxicity, neuropathy and Lipodystrophy, rashes, ADR’s, disturbed sleep.

Question 13

what is lipodystrophy?

Answer 13

This is a common side effect of some antiviral drugs e.g. AZT, stavudine. Loss of subcutaneous fat from face and limbs with redistribution to the breasts and abdomen significantly alters the patient’s appearance. Changing antiviral treatment can result in reversal of the lipodystrophy in some patients. face lift, liposuction and fillers may also be needed for tx.

Question 14

steps for hiv prevention…

Answer 14

condoms, circumcision, use tx properly, Pre-exposure prophylaxis (PrEP) or Post-exposure prophylaxis for sexual exposure (PEPSE), proper use of needles and handling.

Question 15

MDT approaches to care of HIV patients

Answer 15

maintain good physical and mental health, prevent virus transmission, improve quality of life.

Question 16

ways to avoid exposure in healthcare settings

Answer 16

1. Use of good hygiene practices with regular hand washing (before and after contact with each patient, before putting on and after removing gloves).
2. Covering existing wounds or skin lesions with waterproof dressings.
3. Taking simple protective measures to avoid contamination of your person and clothing with blood (use protective clothing, masks, goggles as appropriate and avoid wearing open footwear where blood may be spilled or where sharps are handled).
4. Protecting mucus membranes of eyes, mouth and nose from blood splashes.
5. Preventing puncture wounds, cuts and abrasions in the presence of blood.
6. Avoiding sharps usage where possible.
7. Use of a safe procedure for handling and disposal of sharps.
8. Clearing up spillage of blood and body fluids promptly and disinfecting contaminated surfaces.
9. Disposing of contaminated waste safely.

Question 17

WHO STAGING –> CLINICAL STAGE 1

Answer 17

Asymptomatic, Persistent generalized lymphadenopathy

Question 18

CLINICAL STAGE 2

just read

Answer 18

• Moderate unexplained weight loss (<10% of presumed or measured body weight) • Recurrent respiratory infections (sinusitis, tonsillitis, otitis media, and pharyngitis) • Herpes zoster • Angular cheilitis • Recurrent oral ulceration • Papular pruritic eruptions
• Seborrheic dermatitis • Fungal nail infections

Question 19

CLINICAL STAGE 3

just read

Answer 19

• Unexplained severe weight loss, Severe presumed bacterial infections, Unexplained chronic diarrhea for meningitis, bacteremia) >1 month • Acute necrotizing ulcerative stomatitis, • Unexplained persistent fever for gingivitis, or periodontitis >1 month (>37.6ºC, intermittent or • Unexplained anemia (hemoglobin <8 g/dL) • Persistent oral candidiasis (thrush) • Neutropenia (neutrophils <500 cells/μL) • Oral hairy leukoplakia • Chronic thrombocytopenia• Pulmonary tuberculosis (current).

Question 20

3 other manifestations of HIV disease…

Answer 20

Seborrheic dermatitis, Kaposi’s sarcoma, Lymphoma.

Question 21

Describe the Pathology of HIV

Answer 21

HIV is a retrovirus. CD4 cells are involved in the immune protection. Thhe HIV virus is able to enter these cells via glycoproteins and chemokine co-receptors, the virus is then able to replicate inside cells leading to the destruction and depletion of CD4 cells. Once the virus penetrates the host cell it releases its RNA which must be converted to DNA to allow incorporation into the host genome. This process is known as reverse transcription and requires the enzyme reverse transcriptase. The first group of drugs with activity against HIV were the nucleoside reverse transcriptase inhibitors which include zidovudine (AZT), didanosine (ddI), zalcitabine (ddC), lamivudine (3TC), stavudine (d4T) and abacavir. All of these are nucleoside analogues and therefore interfere with the function of many healthy host cells including marrow cells, as a consequence of which marrow toxicity is a frequently encountered adverse effect.