HIV Flashcards
(17 cards)
Immunology of HIV
Virus binds to CD4 via gp120 –> CD4 migrates to lymphoid tissue where it replicates
Decrease in CD4 in circulation –> immunocompromised
Normal CD4 count
500-1500 cells/mm^3
HIV symptomatic at…
<200 cells/mm^3
HIV virology
RNA - retro virus –> Transcriptase replicates Viral Genome
Viral Integrase integrates the Genome with the Host
Host synthesises Viral Proteins –> Mature subunits
Complete virions Bud and release
Presentation of the Acute HIV infection
Similar to glandular Fever
Rash, Fever, Pharyngitis and Lymphadenopathy
Some patients will develop diarrhoea, meningitis and Neuropathy
Ix of the Acute phase
Acute serum for HIV antibodies - Early sample will be Antibody positive but Antigen negative - within 3 months Ag should become Positive.
During Seroconversion HIV viral load can also be determined
What is Seroconversion stage
Transient illness: 2-6 weeks post-exposure
Fever, malaise, pharyngitis and a macpap rash
Menigoencephalopathy rare
AIDS Related comlex
AIDS prodrome
constitutional B-Symptoms
Opporunistic infection - Candida (oral), Seborrheic dermatitis, recurrent HSV
Investigations of HIV
ELISA - Serum or salivary HIV Abs
Western Blot to confirm
PCR may detect HIV Virions in window period (6mo window)
Rapid antibody test - may give false positive - WB to confirm
Drugs
NNRTI, NRTI, PI - Combine to make HAART
HAART regimens
1 NNRTI + 2 NRTI
1 PI + 2 NRTI
indications for Treatment
CD <350, Aids defining illness, Pregnancy, Co-infection
Complications of HIV
Candida (pulmonary and oesophageal) CMV PCP TB Deep penetrating Cervical cancer Toxoplasmosis lymphoma
What is PEP
Prophylaxis - To be given for 28 day ASAP post exposure to known or potential HIV source
What is PCP
Pneumocystic Pneumonia - Common in HIV pts
Dry cough, Fever, Exertional Dyspnoea
CXR will show bilateral perihilar shadows
Ix of PCP
PCR or Sputum Culture.
May require Lung Bx
Rx of PCP
High dose IV Trimoxazole and prednisolone of severe
