HIV Flashcards
What can HIV be spread by?
- Sexual transmission
- Injection drug misuse
- Blood products
- Vertical transmission
- Organ transplant
What is the most common cause for the spread of HIV?
Most commonly due to sex between men
Can you test unconscious patients for HIV?
Unconscious patients can be testing if you think it is in their interest
How do you test someone for HIV?
Point of care testing is done (POC):
- Blood sample from finger
- Results in 60 seconds
- Negative, positive or invalid
Standard test will then confirm results
What is the immunology of HIV?
Infects and destroys cells of immune system:
- Especially T helper cells that are CD4+ (have a CD4 receptor on their surface)
- CD4 receptors are not exclusive to lymphocytes, also found on macrophages and monocytes, cells in the brain, skin
What cells have CD4 receptors?
T helper cells
Macrophages
Monocytes
Cells in the brain
Cells in the skin
Describe the natural history of a HIV infection?
Over course of infection:
- CD4 count declines and HIV viral load increases
- Increasing risk of developing infections and tumours
- Severity of illness is greater the lower the CD4 count (normal CD4>500)
- Most AIDs diagnosis occur at CD4 count < 200
Symptoms increase as CD4 decreasing, as does opportunistic infections
What is a normal CD4 level?
>500
At what CD4 level do most AIDS diagnosis occur?
<200
Describe the classification of HIV?
Stage 1 - asymptomatic
Stage 2 - <10% BW lost and/or performance scale 2 (symptomatic, normal activity
Stage 3 - >10% BW lost and/or performance scale 3 (bedridden <50% of day dyring last month)
Stage 4 - HIV wasting syndrome and/or performance scale 4 (bedridden, <50% of day during last month
What opportunistic infections are common in HIV?
Thrush
PJP
TB
Cryptosporidiosis
Kaposis
Cryptococcal meningitis
CMV, MAC
When does HIV become AIDS?
- If no symptoms then HIV
- Certain infections and tumours that develop due to weakness in immune system are classified as AIDS illnesses
What are some clinical indicator diseases of HIV?
TB
Pneumocystits
Cerebral toxoplasmosis
Primary cerebral lymphoma
Cryptococcal meningitis
Kaposi’s sarcoma
Persistent cryptosporiosis
Cervical cancer
Cytomegalovirus retinitis
How does mortality in HIV change with CD4 count?
One year mortality increases as CD4 count decreases
Describe the general path of acute infection of HIV to death?
What is the seroconversion illness?
Seroconversion illness is when HIV antibodies first develop:
- Abrupt onset 2-4 weeks post exposure
- Self limiting 1-2 weeks
- Symptoms generally non-specific and differential diagnosis includes a range of common conditions, symptoms includes
- Flu-like illness
- Fever
- Malaise and lethargy
- Pharyngitis
- Lymphadenopathy
- Toxic exanthema
What is the presentation of the seroconversion illness of HIV?
- Abrupt onset 2-4 weeks post exposure
- Self limiting 1-2 weeks
- Symptoms generally non-specific and differential diagnosis includes a range of common conditions, symptoms includes
- Flu-like illness
- Fever
- Malaise and lethargy
- Pharyngitis
- Lymphadenopathy
- Toxic exanthema
What is the most common late stage (AIDS) infection?
Most common late stage (AIDS) infection is pneumocystitis jiroveci pneumonia:
- Opportunistic infection
- CD cell count usually <200
- Classical history of dry cough and increasing breathlessness over several weeks
- Investigations
- Chest x-ray
- Induced sputum or broncoscopy for PCR
- Treatment
- Cotrimoxazole
- Pentamine
- Prophylaxis until CD>200
What is the classical history of pneumocystitis juroveci pneumonia?
- Classical history of dry cough and increasing breathlessness over several weeks
What investigations are done for pneumocystitis jiroveci pneumonia?
- Chest x-ray
- Induced sputum or bronchoscopy for PCR
What is the treatment for pneumocystitis jiroveci pneumonia?
- Cotrimoxazole
- Pentamine
- Prophylaxis until CD>200
What is the treatment of HIV?
Antiretroviral therapy is used:
- Different classes of drugs acting on different stages in HIV lifecycle
- Combination antiretroviral therapy (cART) means at least 3 drugs from at least 2 groups
- Adherence needs to be over 90%
- cART can lead to normal life but side effects can be significant
What does combination antiretroviral therapy (cART) refer to?
- Combination antiretroviral therapy (cART) means at least 3 drugs from at least 2 groups
What does the adherence to HIV treatment need to be for it to work?
- Adherence needs to be over 90%
What are the different classes of antiretroviral therapy?
Entry inhibitors
Reverse transcription inhibitors
Integrase inhibitors
Protease inhibitors
Where does each class of antiretroviral therapy act in the HIV lifecycle?
What is the HIV lifecycle?
1) Binding and entry
2) Reverse transciption
3) Integration
4) Transcription
5) Assembly
6) Release and protease
When should HIV treatment be started?
- Start all patients at diagnosis regardless of CD4 and viral load
- If CFD4 < 350 cells/mm3 patients at risk of developing symptoms without treatment
- Any pregnant woman start before third trimester
- Three drug combination with treatment adjustment if viral load not suppressed after 4-6 weeks
How is treatment initiated in HIV?
- A combination of two nucleoside reverse transcriptase inhibitors (NRTIs) as a backbone regimen plus one of the following as a third drug:
- a non-nucleoside reverse transcriptase inhibitor (NNRTI)
- an integrase inhibitor (INI)
- a boosted protease inhibitor (PI).
What is usually the reason when HIV treatment fails?
When treatment fails is usually due to poor adherence leading to viral mutation and resistance
What are side effects of each antiviral drug for HIV?
- Nucleoside reverse transcriptase inhibitors
- Marrow toxicity, neuropathy, lipodystrophy
- Non-nucleoside reverse transcriptase inhibitors
- Skin rashes, hypersensitivity, drug interactions, neuropsychiatric effects
- Protease inhibitors
- Drug interactions, diarrhoea, lipodystrophy and hyperlipidaemia
- Integrase inhibitors
- Rashes, disturbed sleep
What are side effects for nucleoside reverse transcirption inhibitors?
- Marrow toxicity, neuropathy, lipodystrophy
What are side-effects for non-nucleoside reverse transcription inhibitors?
- Skin rashes, hypersensitivity, drug interactions, neuropsychiatric effects
What are side effects for protease inhibitors?
- Drug interactions, diarrhoea, lipodystrophy and hyperlipidaemia
What are side effects for integrase inhibitors?
- Rashes, disturbed sleep
What is lipodystrophy?
Abnormal distribution of fat
What are some challenges of HIV care?
- Osteoporosis
- Cognitive impairment
- Malignancy
- Cerebrovascular disease
- Renal disease
- Ischaemic heart disease
- Diabetes mellitus
What is HIV prevention done by?
- Behaviour change and condoms
- Circumcision
- Treatment as prevention
- Pre-exposure prophylaxis (PrEP)
- Post-exposure prophylaxis for sexual exposure (PEPSE)
