ID - HIV Flashcards
Life expectancy of HIV +ve patient compared to -ve
8 years less (71 vs 79)
Which HIV patients should you treat with ART?
all
naming convention of HIV drugs
all integrase inhibitors end in: -gravir
Favoured combination of HIV drugs (class wise)
Integrase inhibitor + 2 NRTI
OR
Integrase inhibitor + 1 NRTI
If patient presents with new HIV and opportunistic infection what should you do re HIV meds
Start the HIV meds
2 caveats for delaying treatment:
- TB affecting the brain
- cryptococcal meningitis
(concerns regarding immune over-activation, inflammation and brain herniation)
Tenofovir forms and link
TAF - Tenofovir alafenamide
Prodrug of TDF converted to TDF intracellular
TDF - Tenofovir Disoproxil fumarate
AE Tenofovir (TDF)
renal disease, bone disease (more with TDF)
- less with TAF
Pharmacokinetic relation of tenofovir forms (TAF vs TDF)
Tenofovir alafenamide (TAF) Prodrug of TDF converted to TDF intracellular
TMP-SMX + pred
(Don’t treat CMV in HIV patients unless histological changes suggesting it’s pathogenic)
HIV drugs contra-indicated in pregnancy
all are fine
Abacavir AE
Hypersensitivity reaction ( 5-8%) if HLAB5701
zidovudine AE
anaemia, Lipodystrophy
Cardinal AIDS Defining Illnesses
- Kaposi Sarcoma
- CMV retinitis
- Disseminated Mycobacterium avium complex/Tuberculosis
- Pneumocystis pneumonia
- Oesophageal Candidiasis
- Toxoplasma encephalitis
- Chronic cryptosporidiosis / microsporidiosis
CD4 count that HIV patients tend to get opportunistic infections
typically < 200
Vaccine and HIV
don’t give live vaccines if CD4 < 200
Primary prophylaxis in HIV
HIV chest infections
Pneumococcus (S. Pneumonia)
Pneumocystis (PJP fungus)
TB (re-activation)
PJP
main symptom PJP pneumonia
SOBE
Treatment for PJP pneumonia
trim-sulfa
- needs to make its own folate
Does not have ergosterol in it’s cell membrane therefore other antifungals (azoles/ampho) not effective
Steroids - If PaO2 < 70
Diagnosis of PJP pneumonia
BAL PCR
Indications of PJP prophylaxis (other than HIV with CD4 < 200)
- Prednisone > 20 mg /day for > 4 weeks
- ALL Induction to end of Maintenance
- Allo-HSCT – Engraftment > 6 mos after transplant provide off immunosuppression and no GVHD
- Alemtuzumab, Rituximab, anti-thymocyte - > 6 months after completion
- Solid organ transplant > 6 months (?lifelong for lung/intestinal txplant)
Sx of cryptococcal meningitis
- Presents as subacute meningitis (25% do not have any meningeal signs (serum crypto ag+)
- Due toљ ICH – CN palsies, seizures (cryptococcoma)– but typically confusion and fevers
LP finding crytococcal meningitis
- Opening pressure elevated in 60-80% - very high
- Lymphocytic, low glucose (but only in 40%), elevated protein
- CSF –Crypto Ag 94% positive, Culture 100% - PCR ~80%
mgmt crytococcal meningitis
2 anti-fungal drugs until sterile LP (amphotericin + flucytosine)
then conslidaiton
- fluconazole 8 weeks
Maintenance
- 12 months lower dose fluconazole
Control ICH
- daily LP until < 25cm H2)
Hold off on ARV for a little while - Typically start 4-6 weeks, CSF sterile
HIV CNS toxoplasmosis presentation
- Most common cause of brain abscess – usually CD4 < 100, *<50
- If higher CD4 = need to think TB, lymphoma
- Common presentation – headache, fever, seizures, AMS, focal deficits
- Dx – must have Toxo IgG + serum – PCR of CSF for Toxo
- Imaging – ring enhancing lesions – multiple – single can be confused Lymphoma
Transmission of toxoplasmosis
- Feline feces (cats, lions)
- Oocysts begin to be excreted 20 days post-infection
- Rare meat (Lamb>Beef>Pork)
HIV CNS toxoplasmosis treatment
- TMP-SMX
- Adjuvant dexamethasone, if develop SZ - antiepileptic
Teaching point – treat empirically for toxoplasmosis if ring enhancing lesions – if not better 2 weeks consult NS for brain biopsy
IRIS
immune reconstitution inflammatory syndrome
- results from restored immunity to specific infectious or non-infectious antigens.
- A paradoxical clinical worsening of a known condition or the appearance of a new condition after initiating therapy characterizes the syndrome.
- Many disease entities associated with IRIS – OI’s Sarcoidosis, Grave’s,
- Timing – Usually w/i 6 weeks after ARV
predicters of IRIS in HIV infection
high VL, low CD4 or high pathogen burden
Most common IRIS opportunistic infections
- Mtb, MAI (Mycobacterium avium and intracellulare)
- Cryptococcus
- CMV
IRIS treatment
- Continue ARV
- Steroids – pred 40 -80 mg for 2-8 wks+, NSAID
- Must exclude other entities AND no failure or your treatment of OI
MAI infection
Mycobacterium avium-intracellulare infection
- Decreasing incidence (hence why MAI prophylaxis dropped if starting ARVs)
- Bx, blood cultures
predicters of IRIS in HIV infection
high VL, low CD4 or high pathogen burden
Appearnce of CMV retinitis
Ketchup on eggs
Ix for CMV retinitis
- Fundoscopic exam
- Rarely vitreal tap done
CMV viral load not that helpful (correlates with CD4 count)
Treatment of CMV retinitis
Immediate sight- threatening lesion
* ARV
* IV ganciclovir
* Intravitreal ganciclovir
Small peripheral lesion
* ARV
* Oral valganciclovir
Typically expect improvement in 10-14 days
