HIV Flashcards
what does HIV cause
acquired immunodeficiency (AIDS)
what type of virus is HIV
retrovirus
what is the target site for HIV
CD4+ receptors
effects of HIV on the immune system
- decreases circulating CD4+ cells
- decreases proliferation of CD4+ cells
- decreases CD8+ T cell activation
- decreases affinity of antibodies
- chronic immune activation
what does HIV make people more susceptible to
viral infections
fungal infections
mycobacterial infections
infection-induced cancers
what is the normal CD4+ parameters
500-1600
what are the key features of HIV viral replication
rapid replication in very early and very late infection
what cells does the HIV virus first infect
mucosal CD4 cells
transported to regional lymph nodes
infection established within 3 days of entry
when can post exposure prophylaxis be given and why
within 72 hours of first exposure as the infection needs 3 days to become established
when do primary HIV symptoms occur
2-4 weeks after infection
HIV symptoms seen in 80% of people
Fever maculopapular rash myalgia pharyngitis headache
why are people with primary HIV infection high risk
they have a high viral load
what is an opportunistic infection
infection caused by a pathogen that does not normally produce disease in a healthy individual
what type of pneumonia is seen in HIV
Pneumocystis pneumonia
what organism causes pneumocystis pneumonia
pneumocystis jiroveci
what does the CD4 count need to be for pneumonia to cause symptoms? what are the symptoms?
<200
SOB, dry cough, insidious onset
Diagnostic investigation for pneumocystis pneumonia
bronchoalveolar lavage + immunofluorescence +/- PCR
treatment of pneumocystis pneumonia
high dose co-trimoxazole +/- steroids
What organism causes cerebral toxoplasmosis
toxoplasma gondii (fungal infection)
what CD4 count is there for toxoplasma gondii to cause symptoms
<150
what is seen on CT scan of cerebral toxoplasmosis
multiple ring enhancing lesions
symptoms of cerebral toxoplasmosis
headache fever focal neurology seizures Increased ICP Decreased conscious levels
what does the CD4 count have to be for CMV to cause symptoms
<50
what does CMV cause
Retinitis
Oesophagitis
Colitis
ROC
symptoms of CMV
Abdo pain, diarrhoea, PR bleeding, decreased visual acuity, floaters
what is offered to HIV patients with CD4 count <50
ophthalmic screening to detect CMV
what organism causes progressive multifocal leukoencephalopathy
JC virus
symptoms of progressive multifocal leukoencephalopathy
focal neurology, confusion, personality change
what form of HIV causes neurocognitive impairment
HIV 1
What is the pattern with HIV and neurocognitive impairment
Increased incidence with increased immunosuppression
what is ‘slims disease’
HIV associated wasting/cachexia
what cancers are related to AIDS
Kaposi’s sarcoma
non-hodgkins lymphoma
cervical cancer
what organism is associated with kaposi’s sarcoma
human herpes virus 8 (HHV8)
pathology of kaposi’s sarcoma
vascular tumour
where can kaposi’s sarcoma occur
cutaneous, mucosal, visceral (pulmonary/GI)
treatment of kaposi’s sarcoma
HAART
local therapies
systemic chemotherapy
what organism causes non-hodgkins lymphoma
EBV
Haematological manifestations of HIV
anaemia
Thrombocytopenia
how is HIV most commonly transmitted
sex (mostly men who have sex with men)
where are the endemic areas of HIV
Sub-saharan africa
Caribbean
Thailand
after how long is HIV antibody made
3 months of being infected
best test for HIV
4th generation HIV test- combined antibody + antigen
what is HAART
highly active anti-retroviral therapy
i.e. a combination of 3 drugs from at least 2 drug classes to which the virus is susceptible
Examples of single tablet formulations of HAART
tenofovir
Emitricitabine
Efavirenz
side effects of HAART
GI: nausea, diarrhoea, abdo pain, vomitting
Skin: hypersensitivity, rash, steven Johnston syndrome
CNS: mood changes, psychosis
Renal: proximal renal tublopathies
Bone: osteomalacia
CVS: Increased MI risk
Haematology: anaemia
