HIV Flashcards
WHat does it mean to be a retrovirus?
- use of reverse transcriptase to replicate its RNA strand (for a second RNA strand)
WHere is HIV-2 commonly seen?
- in west Africa
- less frequent thus not often seen
What is the target site for HIV ? What is their role?
- CD4+ receptors
- —-a glycoprotein found on the surface of a range of cells
- —import. for inducing adaptive immune response
How does HIV infections affect immune responses?
- reduced prolif. and circulation of CD4+ CELLS
- reduced C8+ activation
- reduced antibody class switching —reduced Ab affinity
- chronic immune activation in the GUT
What is the CD4 count that puts an individual at risk of opportunistic infections?
- CD4 count below 200 cells/mm3
How rapid is HIV replication ?
- RAPID in EARLY and VERY late infection
- new gen every 6-12 hrs
What is the time to death w.o HIV rx?
- 9-11 years
How long does it take for HIV to establish infection?
within 3 days of entry
therefore ….72 hrs to intervene with prophylaxis
WHat are the symptoms of Primary HIV infection?
- rash; maculopapular
- fever
- swollen glands
- pharyngitis
- Myalgia
- headache/ aseptic meningitis
When does primary HIV infections set in?
What is the risk of person experiencing Primary HIV infection?
- ~2-4 weeks after infection
- VERY high risk of TRANSMISSION
If the glandular test comes out as negative…
- do HIV testing
Define opportunistic infections.
infection caused by a pathogen that does not normally produce disease in a healthy individual—-seeks the Opportunity with a weakened immune system
Most COMMON opportunistic infection in HIV pt?
Wht is the CD4 count like?
pneumocystis pneumonia by pneumocystis jiroveci
- <200
What are the symptoms of p.pneumonia?
insidious onset
- SOB
- Dry cough
- —signs: EXERCISE desaturation (make them walk a flight of stairs 5 times)
How to dx PP?
- PCR
- bronchoalveolarlavage
- immunofluorescence
How to treat pneumocystic pneumonia?
- high dose Co-trimoxazole (w/ or w/o steroid)
–low-dose for Prophylaxis
Symptoms of Cerebral toxoplasmosis?
Headache Fever Focal neurology Seizures Reduced consciousness Raised intracranial pressure
—–very specifc neuro symptoms d/t cerebral abscess
What are symptoms of CMV infection present as?
Reduced visual acuity
Floaters
Abdo pain, diarrhoea, PR bleeding
—-colitis (tender abdomen)
How does HIV- associated neurocognitive impairm/ present as?
Reduced short term memory
+/- motor dysfunction
—-age-related dementia
How may PML appear on CT scan?
- like multiple sclerosis
- —-white matter pathology
- —FRONTAL lobe changes (personality change/ confusion/ focal neurology)
How does HIV- associated wasting present as?
- Slim’s disease (extremely cachexic)
- —-multifactorial (anorexia/metabolic- chronic metabolic activ./ malabsorption/ hypogonadism)
Name an AIDS related cancer. and the causal virus?
Kaposi’s Sarcoma
- Herpes virus 8
EBV causing, AID-related cancer? Presentation?
- non-Hodgkin’s Lymphoma
- More advanced
B symptoms
Bone marrow involvement
Extranodal disease
↑ CNS involvement
Main hematological manifestation of HIV?
Anemia
—-affects up to 90%
Thrombocyotpenia
Factors increasing transmission risk of HIV
Anoreceptive sex
Trauma
Genital ulceration
Concurrent STI
- injection drug use and SHARING
- iatrogenic
- infected blood products
In utero/trans-placental
Delivery
Breast-feeding
Which groups should be tested for HIV?
- universal testing in HIGH prevalence areas (cost-effective)
- opt-out HIV testing in clinical settings (enter a sexual health clinic, drug users)
- screening of HIGH risk groups (MSM/ female partners of BISEXUAL men/ drug injectors/ hiv partner)
- testing on clinical grounds (those with SYMPTOMS
HIV markers for testing?
- HIV antigen develops faster
- — better to test for this than antibodies (appears in 3 months)
What is occurring during asymptomatic HIV infection?
- ongoing VIRAL infection
- ongoing CD4 count depletion
- ongoing IMMUNE activation
- —-onward transmission if UNDIAGNOSED
What is seen on CXR of pneumocystic pneumonia?
- normal
OR - reticulonodular markings
- interstitial infiltrates
What does HIV cause?
- AIDS
(Acquired Immunodeficiency Syndrome) —-> opprotunistic infections or AIDS-related cancers
Is AIDS preventable?
YES
- by early HIV dx and rx
HIV infection is ALSO preventable
Where does Hiv-1 originate from?
- CENTRAL and WEST African chimpanzees
What does CD4 activate?
- Bcells
- cytotoxic T-cells (CD8+)
- cytokine release
- recog. of MHC2 Ag-presenting cell
With HIV’s impact on the immune response, what does this ultimately make one susceptible tO?
VIRAL infections
FUNGAL infections
Mycobacterial infections
Infection-induced cancers
What forms of TB may be seen with HIV infections?
- ones NOT commonly seen in those who are HIV-
- miliary TB
- Lymphadenopathies
- extrapulmonary TB
- Multi-drug resistant TB
- Immune reconstitution Syndrome
What cuases Cerebral Toxoplasmosis?
What is the CD4 count at,?
- causes by Toxoplasma Gondii
- CD4 <150
What occurs is Cerebral toxoplasmosis?
- reactivation of a LATENT infection
- –> MULTIPLE cerebral abscess !
Reactivation of of LATENT CMV infection, results in what?
- retinitis
- colitis
- esophagitis
-CD4 < 50
WHta skin infection may arise IIary to HIV infection?
- Herpes Zoster
- Herpes Simplex
- Human Papilloma virus
- Weird/ Wonderful
WHich skin infection is multidermatomal and RECURRENT ?
- Herpes Zoster !
Which skin infection is extensive and ACLIOCVIR -resistant?
Herpes Simplex
What does HIV-1 cause?
WHen may it occur?
HIV-associated Neurocognitive Impairment
- incr. incidence with Incr. short term immunosuppression
How does HIV-associated Neurocognitive Impairment present as?
- reduced short term memory
+/- MOTOR dysfxn
What does JC virus cause?
at CD4 <100
> progressive multifocal leukoencephalopathy
How does progressive multifocal leukoencephalopathy present as?
- focal neurology
- rapidly progressive
- CONFUSION
- personality change
What are other neurological pres. of HIV>
Distal sensory polyneuropathy Mononeuritis multiplex Vacuolar myelopathy Aseptic meningitis Guillan-Barre syndrome Viral meningitis (CMV, HSV) Cryptococcal meningitis Neurosyphilis
How may HIV affect weight?
- Slim’s Disease
(HIV-associated Wsting)
- could be d.t: > metabolic cause > anorexia > diarrhoea >hypogonadism
Name the 3 cancers HIV may cause?
- Kaposi’s CA
- NON-Hodgkins Lymphoma
- Cervical Cancer
What causes Kaposi’s sarcoma caused by?
Herpes Virus 8 (HHV8)
—-used to affect 40% before antiretroviral drugs era
What is kaposi’s Sarcoma? How is it treated?
- Vascular tumor
2. HAART; Local therapies; systemic chemotherapy
WHat virus causes Non-hodgkin’s lymphoma?
How does it present as?
- EBV
- > bone marrow involvement; extranodal disease; ^ CNS involvement
How does cervical cancer occur ?
- persistence of HPV infection
rapid progression of SEVERE dysplasias and INVASIVE disease
What specific testing should be offered to ALL complicated HPV disease?
- HIV testing
- those with high grade CIN/ VIN/ AIN/ PIN
Name some NON-opportunistic infections for symptomatic HIV.
- mucosal candidiasis
- seborrhoeic dermatitis
- diarrhoea
- fatigue
- worsening of PSORIASIS
- parotitis
- lymphadenopathy
- (STIs/ Hep B/ Hep C)
Name Hematological manifestations in HIV pts. Why may it occur?
Anaemia (90%)
Thrombocyotpenia (ITP)
d.t HIV, Opportunistic inf./ AIDs-Malignancies
