HIV Flashcards
What virus causes HIV infection?
A Lentivirus, genus Retroviridae, single stranded RNA
What is the binding site for CD4 cells?
Envelope protein GP 120
What occurs at the cellular level in HIV infection?
Helper cells are damaged. They normally are responsible for presenting antigen to B cells and stimulating them with cytokines as well as cytotoxic T cells.
IL1 secretion is reduced as well as chemotaxis and cytotoxicity,
How does HIV enter the body?
Via dendritic cells inn the vagina and surface lymphatics.
What is the role of reverse transcriptase?
It permits the viral RNA to enter the nucleus of the immune cells and become part of the cells’ DNA. Replication of the immune cells results in production of the HIV RNA which kill the immune and other cells. Inflammation worsens the process.
What time period is required for HIV dissemination throughout the entire body?
One week.
How long does it take to destroy the immune system?
8 to 10 years.
How many CD4 cells are destroyed daily?
200,000,000,
How many virions are destroyed/ cleared daily?
10,000,000.
What does ART(combination of multiple drugs) do?
It blocks viral replication, resulting in a change in the balance of replication and destruction. The result is and increase in CD4 cells, then memory cells and finally naïve cells.
What are the opportunistic infections (OI) in Africa?
CNS Cryptococcosis, TB, Esophageal Candidiasis, PCP, Amebiasis, CMV Retinitis, CNS Toxo
What are the OI in developed countries?
PCP, Esophageal Candidiasis, MAC Infection, CMV Retinitis, CNS Cryptococcosis, CNS Toxo
At what CD4 count level do the above OI appear?
CD4 of 200 or less
At what CD4 level does Bacterial Pneumonia and Orall Thrush appear?
CD4 count between 500 and 200
What is the treatment for PCP? If sulfa allergic
TMP-SMX3 to 4 X per day, if sulfa allergic use escalating doses of TMP-SMX
When is Prednisone used?
if hypoxic with PaO2 <70, Tapered over 20 days
What infections are frequently concomitant ?
PCP and TB
How does an infection with Toxoplasmosis occur?
Usually from reactivation of oocysts ingested from undercooked pork, lamb and beef
What is the treatment of Toxoplasmosis?
Pyrimethamine + Sulfadiazine + Folinic Acid; steroids are not helpful
When do you suspect disseminated Cryptococcal infection?
When CD4 ct is less than 100
What are the sx of CNS infection?
Progressive severe HA with stiff neck
What physical findings are associated with this infection?
6th nerve palsy due to elevated ICP
Molloscum like skin lesions
Non inflammatory Meningitis
How to make the dx of Cryptococcal Meningitis?
India Ink of CSF is + 75-95% of the time
CRAG
What is the treatment of CNS Cryptococcal Meningitis?
Amphotericin B plus
5 Fluocytosine or Fluconazole
Fluconazole is continued for 10 weeks at 800 mg orally once per day the reduced to 200 mg once daily which is continued indefinitely
What % of Esophageal Infections are caused by Candidiasis?
50-70%
What conditions do you consider when Esophagitis is not associated with systemic sx?
Candidal Esophagitis
Pill Esophagitis-AZT and DDC
What conditions cause Esophagitis with systemic sx?
CMV
Candida
Neoplasm
Idiopathic Ulcer
What causes Bacillary Angiomatosis (BA)?
Bartonella Hensleae ( Cat Scratch Disease) and Bartonella Quintana ( cause of Endocarditis and Trench Fever)
What do the skin lesions of Bacillary Angiomatosis (BA)resemble?
Kaposi’s Sarcoma. The Warthin-Starry Silver Stain helps to distinguish them from each other.
What is the treatment of BA?
Macrolides or Doxycycline
What is Immune Reconstitution Syndrome?
Seen when CD4 count is less than 100. ART administered and immune system improved which recognizes previously unrecognized antigens.
Presents with elevated ICP>250, treated with daily lumbar punctures removing 10 to 30 cc of CSF.
The Iris event is a cytokine storm
The risk is 3 to 6x after 2 weeks of ART. It is treated with 1.5 mg/kg daily for 2 weeks then .75mg.kg for 2 weeks
What are some prophylaxis considerations in HIV?
When CD 4 count is below: 200- PCP 100- Toxoplasmosis 50- MAC, Cryptococcosis and Candida also consider the presence of Hepatitis C and D.
What are the 5 steps in managing HIV ( in Africa)?
- Confirm HIV +
- Stage illness- check CBC, VDRL, CD4 count and CXR
- Prophylax all those who are HIV+ with TMP-SMX
- Counsel all prior to staring therapy
- Start ART
What is ART?
2 NRTIs + 1 NNRTI
What are the NRTIs?
Zidovudine (AZT or ZDV), Lamivudine (3TC)
What are the NNRTIs?
Nevirapine (NVP)
Stavudine (D4T)
Efaverez (EFV)
What is the alternative to ART?
Alluvia (Lopinavir + Ritonavir)
What labs are checked at the monthly visit?
A CD4 count and a viral load. It is expected that the CD4 count will rise >50% over a 6 month period.
What are the complications of HIV infection?
Cardiac- Pericarditis, Cardiomyopathy, Atherosclerosis
Renal- Nephrotic SYndrome (HIVAN)
Neurologic- Dementia, Neuropathy
Oncology- Kaposi’s Sarcoma (due to Herpes Virus) , Lymphoma
Why do the complications occur?
Endothelial Damage cause vascular dysfunction
Elevated IL6 levels, C Reactive Protein, Protein S and C and Triglycerides
Reduced HDL and LDL
Chronic Inflammation
What labs are checked at the monthly visit?
A CD4 count and a viral load. It is expected that the CD4 count will rise >50% over a 6 month period.
What are the complications of HIV infection?
Cardiac- Pericarditis, Cardiomyopathy, Atherosclerosis
Renal- Nephrotic SYndrome (HIVAN)
Neurologic- Dementia, Neuropathy
Oncology- Kaposi’s Sarcoma (due to Herpes Virus) , Lymphoma
Why do the complications occur?
Endothelial Damage cause vascular dysfunction use Carotid Intimal Thickness to measure
Elevated IL6 levels, C Reactive Protein, Protein S and C and Triglycerides
Reduced HDL and LDL
Chronic Inflammation
What are the risks of HAART?
Interaction with Statins via P450-3A4 Hypertension after 5 years Type 2 DM Lipodystrophy Hyperlipidemia Myocardial Infarction
What drugs cause Hyperlipidemia?
Protease Inhibitors- Lopinavir , Staduvidine and Ritonavir
NRTI- Abacavir
What are the 4 stages of HIV/
- Generalized Lymph Nodes, no sx
- Weight Loss with Mucocutaneous Disease
- Greater than 10% Weight Loss- Chronic Diarrhea, Fever, TB, ANUG, Hairy Leukoplakia
- Wasting- opportunistic infections(CD4<100)
Who are the priority patients with HIV infection?
Pregnant Women
Children
Those who are obviously Ill
What is a PIMA?
A POC test with CD4 count in 15 minutesl
What is PEP?
Start 24-36 hrs post exposure and use for 4 weeks. retest at 6 weeks, 12 weeks and 6 mos. The cances of acquiring HIV from a needle stick is 0.33%.The drugs used are Truvada or Combivir for low risk and for high risk 2 NRTIs + Ritonovir (PI) or Kaletra (Lopinavir +Ritonovir)
When to start HIV therapy in children?
Under 24 mos. and/or stage 3 or 4 btwn 24 mos and 5 yrs, when CD4 <750 5 yrs+ when CD4 <350 All HIV exposed- TMP-SMX TB exposed, active or inactive- start INH
What is PREP?
Truvada (Tenofovir + Emtricibine) for discordant sexual partners.
What is PEP?
Start 24-36 hrs post exposure and use for 4 weeks. retest at 6 weeks, 12 weeks and 6 mos.
What increases risk of transmission in pregnancy?
Preterm <34 weeks Birth Weight , 2500 gms ROM > 4hrs Low Maternal CD4 count Maternal use of recreational drugs
What are the treatments for HIV in pregnancy?
1) AZT BID, add NVP for 1 dose at onset of albor if less than 4 weeks of therapy then
AZT+ 3TC during L and D and for 7 days post partum
2) Triple drug therapy starting at 14 weeks
What are the treatments for HIV in pregnancy?
1) AZT BID, add NVP for 1 dose at onset of labor if less than 4 weeks of therapy then
AZT+ 3TC during L and D and for 7 days post partum
2) Triple drug therapy starting at 14 weeks
What is the infant regimen?
NVP for 4 to 6 weeks or until 1 week post stopping breast feeding
NVP or bid AZT for 4 to 6 weeks
