HIV - clinical pathology and presentation

Question 1

What is HIV?

Answer 1

Human immunodeficiency virus

RNA retrovirus - uses enzyme reverse transcriptase to make copies of self

Question 2

How long does it take for infection to be established and disseminated throughout the bodies lymph tissue?

Answer 2

72 hours

Question 3

Infection occurs at mucosal surfaces. What receptor does it initially infect?

Where does infection spread to after this?

Answer 3

CD4+ - mainly on T helper lymphocytes

Lymph nodes

Question 4

How does HIV come to exist within a cells genome (integration)?

Answer 4

Viral RNA undergoes reverse transcriptase to become DNA which then integrates within the cells genome in the nucleus

Question 5

What effect does HIV affect on immune response?

What does this lead to?

Answer 5

Reduced CD4+ cells
Reduced CD8+ activation

Chronic immune activation (overreaction of certain parts of immune system)

Puts patient at higher risk of infections and infection-induced cancers

Question 6

During the primary infection stage, there is a very high risk of trasmission.

How long after infection is this stage?
80% present with symptoms. What are these symptoms?

Answer 6

2-4 weeks post infection

Headache
Fever
Myalgia
Pharyngitis
Maculopapular rash - trunk and face

Question 7

What is AIDS? (we no longer use this term)

Answer 7

AIDS = AIDS defining symptomatic HIV

To patients tend to refer to it as symptomatic HIV

Question 8

What is one of the most common respiratory opportunistic infections seen in those with HIV?

What organism causes it?

How does it present?
What is the main invx you would do in clinic?

How is it formally diagnosed?

How is it treated?

Answer 8

PCP - pneumocysitis pneumonia

Pneumocystis jiroveci

Insidious onset of cough and SOB

Exercise induced oxygen desaturation (on walking up stairs etc, pulse increases and sats decrease drastically)

Bronchoscopy and immunfluroscence

High dose Co-trimoxazole

Question 9

CD4 count of less than what is when people are most likely to get opportunistic infections?

A CD4 level of what is normal

Answer 9

<200

> 500

Question 10

What opportunistic infection presents with multiple cerebral abscess?

What is seen on CT?

Answer 10

Cerebral toxoplasmosis

Multiple Ring enhanced lesions
surrounding oedema

Question 11

If you have a CD4 count <200 what prophlyaxis are you on?

Why?

Answer 11

Co-trimoxazole

Protect against PCP and slightly against cerebral toxoplasmosis

Question 12

CMV (cytomegalovirus) causes what symptoms if reactivated?

Answer 12

Retinitis, colitis and oesophagitis

Reduced visual acuity
Floaters
Abdo pain, diarrhoea, PR bleeding

Question 13

What level of CD4 is required to get regular ophthalmic screening?

Answer 13

<50

Question 14

Why does HIV have a neurotoxic affect?

Answer 14

Affects microglial cells

Question 15

What organism causes progressive multifocal leukoencephalopathy?

This presents with an MS like picture

Answer 15

JC virus

Question 16

Patient presents with shingles/HPV/HSV that is persistent/recurrent.
What should you do?

Answer 16

HIV test

Question 17

What is the classical build of someone with untreated HIV?

Answer 17

Cachexic - “Slim’s disease”

Question 18

Kaposi’s scarcoma is a vascular tumour caused by what?

It is an AIDS related cancer.

Where do they present?
How is it treated? How does this change if they present viscerally e.g. pulmonary?

Answer 18

HHV8 - human herpes virus 8

Anywhere

Anti-reterovirals
Local therapies - liquid nitrogen

Need chemo

Question 19

Prior to developing AIDS defining symptomatic HIV - patients have an asymptomatic/non-AIDS defining symptomatic HIV.

Describe some of the symptoms

Describe blood symptoms

Answer 19

Thrush 
Seborrhoeic dermatitis 
Diarrhoea 
Fatigue
Worsening psoriasis

Neurological symptoms e.g. Guillan-Barre syndrome

Leukopenia + thrombocytopenia - these are important