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Flashcards in HIV Deck (70):
1

What is HIV?

Retrovirus
HIV-2 originated in West African Sootey mangabey
Less virulent
HIV-1 originated in Central/West African chimpanzees: HIV1 group M responsible for global pandemic

2

What is the target site for HIV?

CD4+ receptors

3

What cells are CD4+ receptors found on?

T helper lymphocytes
Dendritic cells
Macrophages
Microglial cells

4

What do CD4+Th lymphocytes do?

Essential for induction of adaptive immune response
Recognition of MHC2 APC
Activation of B cells
Activation of cytotoxic CD8+ T cells
CK release

5

What effect does HIV infection have on immune response?

Sequestration of cells in lymphoid tissues
-Reduced circulating CD4+ cells
Reduced proliferation of CD4+ cells
Reduction CD8+ (cytotoxic) T cell activation
-Dysregulated expression of cytokines
-Increasing susceptibility to viral infections (including HIV)
Reduction in antibody class switching
-Reduced affinity of antibodies produced
Chronic Immune Activation (microbial translocation)

6

What does HIV increase susceptibility to?

Viral infections
Fungal infections
Mycobacterial infections
Infection-induced cancers

7

At what CD4+Th count is there a risk of opportunistic infection?

<200cells/mm3
Normal is 500-1600

8

Describe HIV viral replication

Rapid in very early and very late infection
New generation every 6-12hours

9

How does HIV spread in the body?

Infection of mucosal CD4 cell (Langerhans/dendritic)
Transport to RLNs
Infection established within 3 days of entry
Dissemination of virus

10

When is the usual onset of HIV?

2-4wks after infection

11

What are the common symptoms of primary HIV infection?

Fever
Rash (maculopapular)
Myalgia
Pharyngitis
Headache/aseptic meningitis
Up to 80% present with symptoms

12

What happens during the asymptomatic HIV infection?

Ongoing replication
Ongoing CD4 count depletion
Ongoing immune activation
Risk of onward transmission if remains undiagnosed

13

What is an opportunistic infection?

An infection caused by a pathogen that does not normally produce disease in a healthy individual. It uses the “opportunity” afforded by a weakened immune system to cause disease

14

What organism causes pneumocystis pneumonia?

Pneumocystis jiroveci

15

What are the symptoms and signs of pneumocystis pneumonia?

Insidious onset
SOB
Dry Cough
Exercise desaturation

16

How is pneumocystis pneumonia diagnosed?

CXR: May be normal, interstitial infiltrates, reticulonodular markings
BAL and immunofluorescence +- PCR

17

What is the treatment and prophylaxis for pneumocystis pneumonia?

Rx- High dose co-trimoxazole (+- steroid)
Proph: Low dose co-trimoxazole

18

What tuberculosis infections/conditions are more common in HIV+ than HIV- individuals?

Symptomatic primary infection
Reactivation of latent TB
Lymphadenopathies
Miliary TB
Extrapulmonary TB
Multi-drug resistant TB
Immune reconstitution syndrome

19

What organism causes cerebral toxoplasmosis?

Toxoplasma gondii

20

What happens in cerebral toxoplasmosis?

Reactivation of latent infection
Multiple cerebral abscess (chorioretinitis)

21

What are the symptoms/signs in cerebral toxoplasmosis?

Headache
Fever
Focal neurology
Seizures
Reduced consciousness
Raised intracranial pressure

22

What does CMV cause?

Retinitis, colitis, oesophagitis

23

How does CMV present?

Reduced visual acuity
Floaters
Abdo pain
Diarrhoea
PR bleeding

24

What skin infections can be due to HIV?

Herpes Zoster: Multidermatomal, Recurrent
Herpes Simplex: Extensive, Hypertrophic, Aciclovir resistant
Human papilloma virus: Extensive, Recalcitrant, Dysplastic
Penicilliosis
Histoplasmosis

25

What causes HIV-associated neurocognitive impairment?

HIV-1

26

How does HIV-associated neurocognitive impairment present?

Reduced STM
+- motor dysfunction

27

What causes progressive multifocal leukoencephalopathy?

JC virus
Reactivation of latent infection

28

How does progressive multifocal leukoencephalopathy present?

Rapidly progressing
Focal neurology
Confusion
Personality change

29

What are some other neurological presentations of HIV?

Distal sensory polyneuropathy
Mononeuritis multiplex
Vacuolar myelopathy
Aseptic meningitis
Guillan-Barre syndrome
Viral meningitis (CMV, HSV)
Cryptococcal meningitis
Neurosyphilis

30

What causes HIV-associated wasting aka Slim's Disease?

Metabolic (chronic immune activation)
Anorexia (multifactorial)
Malabsorption/diarrhoea
Hypogonadism

31

What causes Kaposi's sarcoma?

Human herpes virus 8 (HHV8)

32

What is the basic pathology of Kaposi's sarcoma?

Vascular tumour

33

How does Kaposi's sarcoma present?

Cutaneous
Mucosal
Visceral- pulmonary, GI

34

What is the treatment for Kaposi's sarcoma?

HAART
Local therapies
Systemic chemotherapy

35

What causes Non-Hodgkins lymphoma?

EBV (Burkitt’s lymphoma, primary CNS lymphoma)

36

How does Non-Hodgkins lymphoma present?

More advanced
B symptoms
Bone marrow involvement
Extranodal disease
Increased CNS involvement

37

What should be offered to all with complicated HPV disease?

HIV testing

38

How can cervical cancer present?

Recalcitrant warts
High grade CIN, VIN, AIN, PIN

39

What are the clinical features of non-OI symptomatic HIV?

Mucosal candidiasis
Seborrhoeic dermatitis
Diarrhoea
Fatigue
Worsening psoriasis
Lymphadenopathy
Parotitis
Epidemiologically linked conditions: STIs, Hepatitis B, Hepatitis C

40

What are some haematologic manifestations of HIV?

Anaemia
Thrombocytopenia

41

What are the modes of transmission of HIV?

Sexual
Parenteral
Mother to Child

42

What factors increase transmission risk of HIV in sex?

Anoreceptive sex
Trauma
Genital ulceration
Concurrent STI

43

How does parenteral transmission of HIV occur?

Injection drug use (sharing 'works')
Infected blood products
Iatrogenic

44

How does MTCT of HIV occur?

In utero/trans-placental
Delivery
Breast-feeding

45

What is the sex ratio of HIV?

2.1:1 M:F

46

What risk group has the highest proportion of HIV in the UK?

MSM

47

What services include an opt-out HIV test?

TOP services
GUM
Drug dependency services
Antenatal services
Assisted conception services

48

What high risk groups should regular HIV screening be carried out on?

MSM
Female partners of bisexual men
IVDU
Partners of people living with HIV
Adults, children, sexual partners, and people with history of iatrogenic exposure from/in an endemic area

49

What are the high prevalence areas of HIV?

Sub-Saharan Africa
Caribbean
Thailand

50

When HIV falls within the DDx what should be performed regardless of risk factors?

HIV test
Risk assessment not necessary

51

What is important when taking an HIV test of an incapacitated person?

Only test if in patients best interest
Consent from relative not required
If safe, wait until patient regains capacity
Obtain support from HIV team if required

52

Which markers of HIV are used by labs to detect infection?

RNA (viral genome)
Envelope proteins (gp120)
Capsule protein (p24)

53

What do 3rd generation HIV tests detect?

HIV 1+2 antibody
IgM
IgG

54

What is the window period of 3rd generation HIV tests?

Avg. 20-25 days

55

What do 4th generation HIV tests detect?

Combined antibody and antigen (p24)

56

What is the window period of 4th generation HIV tests?

14-28 days

57

What is the recent infection testing algorithm?

Can be used to identify if an infection occurred within the preceding 4-6months

58

How does RITA work?

Measure different types of antibodies or strength of antibody binding- HIV1, subtype B

59

What are the targets for anti-retroviral drugs?

Reverse transcriptase
Integrase
Protease
Entry: fusion, CCR5 receptor
Maturation

60

What was shown to have in vitro activity against HIV?

Nucleotide analogues reverse transcriptase inhibitors (NRTI) e.g. zidovudine

61

What is highly active anti-retroviral therapy (HAART)?

A combination of three drugs from at least 2 drug classes to which the virus is susceptible

62

What is most important in preventing drug resistance in HIV?

Adherence

63

What are the S/Es of HAART?

GI S/Es (protease inhibitors), transaminitis, fulminant hep (nevirapine, most others)
Skin: rash, HS, SJS (abacavir, nevirapine)
CNS: mood, psychosis (efavirenz)
Renal: proximal renal tubulopathies (tenofovir, atazanavir)
Bone: osteomalacia (tenofovir)
CVS: increased MI risk (abacavir, lopinavir, maraviroc)
Haematology: anaemia (zidovudine)

64

What enzymes do protease inhibitors interact with?

Liver enzyme inhibitors

65

What enzymes do NNRTIs interact act with?

Liver enzyme inducers

66

Describe partner notification and disclosure in HIV

Voluntary process- may takes weeks, months, years
Duty of care to a known third party

67

How can you prevent onward HIV sexual transmission?

Condom use
HIV treatment
STI screening and treatment
Sero-adaptive sexual behaviours
Disclosure
Post-exposure prophylaxis
Pre-exposure prophylaxis

68

What are conception options for an HIV+ male, HIV- female?

Timed unprotected sex with HAART
Treatment as Prevention

69

What are conception options for an HIV+ female, HIV-male?

? Self-insemination
Timed unprotected sex with HAART
Treatment as Prevention

70

How can you prevent mother to child transmission?

HAART during pregnancy
Vaginal delivery if undetected viral load
Caesarean section if detected viral load
4/52 PEP for neonate
Exclusive formula feeding