HIV: pathophysiology and presentations Flashcards Preview

Repro > HIV: pathophysiology and presentations > Flashcards

Flashcards in HIV: pathophysiology and presentations Deck (68):
1

What can HIV cause/lead to?

AIDS - Acquired Immunodeficiency Syndrome
Opportunistic infections
AIDS-related cancers

2

What is the life expectancy of people with HIV?

"near normal"

3

What is HIV?

A retrovirus

4

Describe HIV-1

Originated in Central/West African chimpanzees
Responsible for pandemic starting in 1981

5

Describe HIV-2

Originated in West African Sootey mangabey (Simian ID virus)
Less virulent

6

What is CD4?

CD4+ receptors are the target site for HIV
A glycoprotein found on the surface of a range of cells

7

What cells are CD4 receptors found on?

T helperlymohocytes (CD4+ cells)
Dendritic cells
Macrophages
Microglial cells

8

What do CD4+ Th lymphocytes do?

Essential for induction of adaptive immune response
Recognition of MHC2 antigen-presenting cell
Activation of B-cells
Activation of cytotoxic T-cells (CD8+)
Cytokine release

9

What does HIV do to the immune response?

Reduced circulating and proliferating of CD4 cells
Dysregulation expression of cytokines
Increased susceptibility to viral infections
Reduced affinity of antibodies produced

10

What are HIV sufferers susceptible to?

Viral infections
Fungal infections
Mycobacterial infections
Infection-inducing cancers

11

What is the normal range of CD4+Th cells?

500-1600 cells/mm*3

12

What number of CD4+Th cells give risk to opportunistic infections?

<200 cells/mm*3

13

Describe HIV viral replication?

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

14

What is the prognosis of HIV without treatment (on average)?

9-11 years

15

How does the infection take place?

Infection of mucosal CD4 cell (Langerhans and Dendritic cells
Transport to regional lymph nodes
Infection established within 3 days of entry
Dissemination of virus

16

How long after infection does it take for symptoms to present?

Usually 2-4 weeks

17

What are the symptoms of a primary HIV infection?

Fever
Rash (maculopapular)
Myalgia
Pharyngitis
Headache/ aseptic meningitis

18

What occurs in asymptomatic HIV infection?

Ongoing viral replication
Ongoing CD4 count depletion
Ongoing immune activation
Risk of transmission

19

What is the definition of an Opportunistic infection?

An infection caused by a pathogen that does not normally produce disease in a healthy individual. But does when afforded the opportunity by a weakened immune system.

20

What organism causes Pneumocystis pneumonia and what CD4 count is needed for this?

Organism - Pneumocystis jiroveci
CD4 count: <200

21

What are symptoms and signs of Pneumocystis pneumonia

Symptoms: insidious onset, SOB, dry cough
Signs: Exercise desaturation

22

How do you diagnose Pneumocystis pneumonia?

BAL and immunoflourescence +/- PCR

23

What is the treatment and prophylaxis for Pneumocystis pneumonia?

Treatment: High dose co-trimoxazole (+/- steroid)
Prophylaxis: Low dose co-trimoxazole

24

What other opportunistic infection that effects the respiratory system can occur in HIV?

TB

25

What organism causes Cerebral Toxoplasmosis and what CD4 level is needed?

Organism: Toxoplasma gondii
CD4 level: <150

26

What is cerebral toxoplasmosis?

reactivation of latent infection
Multiple cerebral abscess (Chorioretinitis)

27

What are symptoms/signs of cerebral toxoplasmosis?

Headache
Fever
Focal neurology
Seizures
Reduced conscioussness
Raised ICP

28

What organism causes Cytomegalovirus and what CD4 count is needed?

Organism: CMV
CD4 level: <50

29

What is CMV?

Reactivation of latent infection.

30

What are causes of CMV?

Retinitis
Colitis
Oesophagitis

31

How does CMV present?

Reduced visual acuity
Floaters
Abdo pain, diarrhoea, PR bleeding

32

When is screening for CMV done?

Individuals with a CD4 level of <50

33

What skin infections can occur with HIV?

Herpes zoster
Herpes simplex
HPV
Penicilliosis
Histoplasmosis

34

What is HIV-associated neurocognitive impairment?

Caused by HIV-1
Any reduced CD4 level

35

How does HIV-associated neurocognitive impairment present?

Reduced short term memory
+/- motor dysfunction

36

What is Progressive multifocal leukoencephalopathy?

Caused by JC virus
CD4 level of <100

37

How does Progressive multifocal leukoencephalopathy present?

Rapidly progressing
Focal neurology
Confusion
Personality change

38

List 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

39

What causes kaposi's Sarcoma and what is it?

Human Herpes virus 8 (HHV8)
Vascular tumour

40

What CD4 level is needed for Kaposi's sarcoma?

Any reduced level

41

How does Kaposi's sarcoma present?

Cutaneous
Mucosal
Visceral - pulmonary, GI

42

How do you treat Kaposi's sarcoma?

HAART
Local therapies
Systemic chemotherapy

43

What organisms cause non-Hodgkins lymphoma and what CD4 level is needed?

EBV (Burkitt's lymphoma), primary CNS lymphoma
Any reduced CD4 level

44

What is the presentation of non-Hodgkins lymphoma?

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

45

What is the diagnosis and treatment of non-Hodgkins lymphoma?

Diagnosis - Same as HIV
Treatment: Same as HIV + HAART

46

What organism causes Cervical cancer?

HPV

47

What is cervical cancer?

Rapid progression to severe dysplasias and invasive disease

48

Name some non-OI of symptomatic HIV

Mucosal candidiasis
Seborrhoeic dermatits
Fatigue + diarrhoea
Worsening psoriasis
Lympadenopathy
parotitis

49

What causes haematologic manifestations?

HIV
OI's
AIDS - malignancies
HIV drugs

50

What are haematological manifestations of HIV?

Anaemia
Thrombocytopenia

51

What CD4 level is needed for haematological manifestations to present?

Any reduced CD4 level

52

What factors increase the risk of HIV transmission?

Anoreceotive sex
Trauma
Genital ulceration
Concurrent STI

53

What ways can a mother pass HIV on to her child?

In utero/trans-placental
Delivery
Breast-feding

54

What is the prevalence of HIV in the UK?

1.5/1000

55

How many people are living with diagnosed HIV in Tayside?

366

56

What markers of HIV are used in labs to detect infection?

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

57

When were HIV antibody tests first introduced?

1985

58

What is the window period for HIV antibody testing?

~63 days

59

What antibodies are detected in 3rd generation HIV?

IgG and IgM

60

What is the window period for 3rd generation HIV antibody testing?

~average of 20-25 days

61

Describe 4th generation HIV tests

Combined antibody and antigen (p24)
Shortens window period by ~5 days (around 14-28 days)
Variability between assays and between labs

62

What is POCT?

A rapid HIV test
results in 20-30 mins
3rd generation (ab only)
4th generation (ab/ag)

63

What are the advantages of POCT?

Simple to use
No lab needed
No venepuncture needed
No anxious wait
Reduce follow up
Good sensitivity

64

What are the disadvantages of POCT?

Expensive -£10
Quality control
Clinical governance
Poor +ve predictive value in low prevalence settings
Not suitable for high volume
Cant be relied on in early infection

65

What does RITA stand for?

Recent Infection
Testing Algorithm

66

Describe RITA?

Used to identify if an infection occured within the preceeding 4-6 months
Measure different types of antibodies or strength of antibody binding

67

What are the advantages of RITA?

Surveillance
Local epidemiology
Assess HIV testing programmes
Inform partner notification
Safer sex advice
Interpretation of CD4

68

What are the disadvantages of RITA?

Accuracy
Patient distress
Criminilisation