HIV lecture Flashcards
How is HIV spread?
Sexual transmission
Injection drug misuse
Blood products
Vertical transmission
Organ transplant
Can you test an unconscious patient for HIV?
Unconscious patients can be tested if you think it is in the patient’s interest to have the test
How does HIV affect the immune system?
HIV infects and destroys cells of the immune system especially the T-Helper cells that are CD4+ (have a CD4 receptor on their surface)
CD4 receptors are not exclusive to lymphocytes – they are also present on the surface of macrophages and monocytes, cells in the brain, skin, and probably many other sites
How does CD4 count change over the course of the disease?
Increasing risk of developing infections and tumours
The severity of these illnesses is greater the lower the CD4 count (normal CD4 > 500)
Most AIDS diagnoses (severe infections) occur at CD4 count <200
Give features of clinical stage 1 HIV infection
Asymptomatic
Persistent generalised lympahdenopathy
Performance scale 1
Asymptomatic, normal activity
Give features of clinical stage 2 HIV
Weight loss (less than 10% body weight)
Herpes zoster within the last 5 years
Recurrent upper respiratory tract infections
Minor mucocutaneous manifestations (seborrheic dermatitis, fungal nail infections, recurrent oral ulcerations)
Performance scale 2:
Symptomatic normal activity
Give features of stage 3 HIV
Weight loss greater than 10%
Unexplained chronic diarrhoea for over 1 month
Prolonged fever over 1 month
Oral candidiasis
Severe bacterial infections
Performance scale 3: Bedridden for less than 50% of the day
Give features of stage 4 HIV
HIV wasting syndrome
Toxoplasmosis of the brain
Progressive multifocal leukoencephalopathy
Candidiasis of the oesophagus, trachea bronchi or lungs
Extrapulmonary TB
Performance scale 4 - bedridden for over 50% of the day during the last month
What is an AIDS illness?
Certain infections and tumours that develop due to a weakness in the immune system are classified as AIDS illnesses. If you have no symptoms then you have HIV infection only.
What are the AIDS defining conditions of the lungs?
Tuberculosis
Pneumocystis
What are the aids defining conditions of the brain?
Cerebral toxoplasmosis (parasitic infeciton of the brain)
Primary cerebral lymphoma
Cryptococcal meningitis
Progressive multifocal leucoencephalopathy (white matter diseases)
What are the aids defining conditions of the skin?
Kaposi’s sarcoma
What are the aids defining conditions of the stomach and intestines?
Persistent cryptosporidiosis
What are the aids defining cacners?
Non-hodgkins lymphoma
What is the aids defining condition of the female reproductive system?
Cervical cancer
What is the aids defining condition of the eyes?
Cytomegalovirus retinitis
For reference
For reference
What is the natural history of HIV/AIDS
Acute infection - seroconversion
Asymptomatic
HIV related illness
AIDS defining illness
Death
What percentage of patients experience seroconversion illness?
30-60%
Abrupt onset 2-4 weeks post exposure
Self-limiting 1-2 weeks
Symptoms are non-specific
What are the symptoms of seroconversion illness?
Flu-like illness
Fever
Malaise and lethargy
Pharyngitis
Lymphadenopathy
Toxic exanthema
“looks like glandular fever but EBV serology not in keeping”
What are the classes of antiretroviral drugs?
Nucleoside reverse transcriptase inhibitors (NRTIs) - abacavir, zidovudine
Non-nucleoside reverse transcripatse inhibitors (NNRTIs) - efavirenz
Protease inhibitors (PIs) - atazanavir
Integrase Inhibitors - Raltegravir
Entry inhibitors (including fusion inhibitors)
What are the standard combination antiretroviral regimens?
Two NRTI’s together with an NNRTI
or
Protease inhibitor
or
Integrase inhibitor
(Lecture says - Combination antiretroviral therapy (cART) means at least 3 drugs from at least 2 groups
Adherence needs to be over 90% - support patient
cART can lead to a normal life but side effects can be significant eg metabolic, lipodystrophy)
Why is ritonavir given with protease inhibitors?
Massivley increases the concentrations and elimination half-lives of other PIs by inhibiting their metabolism by cytochrome P450 - Prolongs the PI’s half-life, allowing reduction in pill burden and dosing frquency - optimising adherence
When should ART commence?
Consider starting all patients at diagnosis regardless of CD4
If CD4 < 350 cells/mm3 encourage patients to start treatment (or clinical stage 3-4)
If CD4 < 200 need to start as soon as possible
Any pregnant woman – start before third trimester
Three drug combination with treatment adjustment if viral load not adequately suppressed after 4-6 weeks of therapy
HIV infected partners in serodiscordant couples should commence ART irrespective of their CD4 count or clinical stage - reduces risk of transmission to unaffected partner
Other patients who should start ART earlier include those with chronic liver disease from viral hepatitis, non-AIDS malignancies, and conditions requiring long-term immunosuppression therapy
How long is the treatment for HIV?
Once you start treatment you need to continue it for the rest of your life. The treatment may need to be changed from time to time but you will always need to be taking some form of antiviral medication.
In many ways, the treatment of HIV is similar to that of a chronic condition (like hypertension) rather than to the treatment of an infection.
What is the result of poor adherence?
Viral mutation and resistance
What are the side effects of nucleoside reverse transcriptase inhibitors?
–marrow toxicity, neuropathy, lipodystrophy
What are the side effects of non-nucleoside reverse transcriptase inhibitors?
–skin rashes, hypersensitivity, drug interactions
What are the side effects of protease inhibitors?
–drug interactions, diarrhoea, lipodystrophy and hyperlipidaemia.
Hyperlipidaemia comes with an increased risk of MI
What are the side effects of integrase inhibitors?
Rashes
What are the challenges of HIV care in 2018?
Osteoporosis
Cognitive impairment
Malignancy
Cerebrovascular disease
Renal disease
Ischaemic heart disease
Diabetes mellitus
What are HIV prevention methods?
Behaviour change and condoms
Circumcision (reduces risk of transmission from women to men)
Treatment as prevention
–VL undetectable = untransmissable (pregnancy)
Pre-exposure prophylaxis (PrEP)
Post-exposure prophylaxis for sexual exposure (PEPSE)
