HIV AB

Question 1

What is the most common type of HIV in Australia?

Answer 1

HIV 1 - type b

Question 2

What is the risk of HIV transmission in the following situations?

Receptive anal sex
Receptive vaginal sex
Needlestick
Mother to child

Answer 2

Receptive anal sex

Question 3

Which coinfections increase the transmission rate of HIV?

Answer 3

Syphilis
HSV
Chancroid

Question 4

What genetic factors are protective against becoming infected with HIV?

Answer 4

CCR5 D32 homozygotes

Question 5

What are the main determinants of life expectancy in HIV now?

Answer 5

Lifestyle factors

Question 6

What is the humoural response to HIV infection?

Answer 6

Type specific neuralising Ab against the V3 loop of gp120 of specific single isolates

Group specific neutralising antibodies against a broad range of isolates

Question 7

What is the mechanism of humoral dysfucntion in HIV infection?

Answer 7

HIV induces high levels of gamma globulin and B cell hyperreactivity

Continued B cell expansion - stimulated by abnormal T cell response

Question 8

What is the main mechanism of CD4 depletion?

Answer 8

Direct infection of CD4 T cells (GIT > blood)

Also indirect through immune activation, apoptosis, infection of CD4 progenitors (CD34+), thymocyte depletion etc.

Question 9

What viral factors determine disease progression?

Answer 9

Weakened viral strains - e.g. gene deletion (Nef)

CCR5 using viruses

Co-infection with CMV (PCR positive) accelerates disease progression on and off ART

Question 10

What immunological factors determine disease progression?

Answer 10

High titre neuralising Ab

High level CD8+ HIV-1 specific T cells

High level CDD4+ HIV-1 specific proliferative

Question 11

What genetic factors determine disease progression?

Answer 11

Chemokine mutations, e.g. CCR5 D32 heterozygote - slower disease progression

Intracellular factors e.g. APOBEC2, TRIM5a, Tetherin, SAMHD1

HLA types

Question 12

Which HLA types convey good prognosis in HIV?

Answer 12

B13, B27, B57

Question 13

Which HLA types convey a poor prognosis in HIV?

Answer 13

A23, B37, B49

Question 14

HIV - what are the associated malignancies and below what CD4 count do they occur?

Answer 14

CD4 less than 200

• Kaposi’s sarcoma
• NHL
• Primary CNS lymphoma
• CIN
• Hairy leukoplakia

Question 15

HIV - which infections frequently occur with CD4 count 200-500?

Answer 15

Herpes zoster
Pneumococcal pneumonia
Oral candidiasis
TB

Question 16

HIV - which infections frequently occur with CD4 count 50-200?

Answer 16

PJP

Question 17

HIV - which infections frequently occur with CD4 count less than 100

Answer 17

Toxoplasma - pneumonitos, CNS

Cryptococcus

Question 18

Which infections frequently occur with CD4 count less than 50

Answer 18

MAC
Cryptosporidiosis
CMV retinitis

Question 19

What is the most common opportunistic infection in AIDS?

Answer 19

PCP

Question 20

Which infections affect the CNS WITHOUT mass effect on neuroimaging in HIV?

Answer 20

PML
HIV encephalitis
HSV
VZV
Cryptococcus

Question 21

What are examples of non-infective CNS disease in HIV?

Answer 21

Malignancy, e.g. primary CNS lymphoma
GBS
CIDP
Bell's palsy
HIV encephalitis
AIDS dementia

Question 22

What rheumatological conditions may be seen in HIV?

Answer 22

ITP
Reiter’s
Polymyositis

Sjogren’s
Seborrhoeic dermatitis