Clinical aspects of HIV infection

Question 1

What occurs during the course of HIV infection?

Answer 1

-CD4 count declines & HIV viral load increases
-Increasing risk of developing infections and
tumours
-The severity of these illnesses is greater the
lower the CD4 count
-Most AIDS diagnoses occur at CD4 count <200

Question 2

What are the medical benefits of early HIV diagnosis?

Answer 2

-Treatments available (ART/ARV) not cure, but
prevent people becoming unwell
-Prophylaxis against opportunistic infections if
appropriate
-Reduce inappropriate investigations if unwell
-Reduce perinatal transmission: treatment for mother (reduce viral load);appropriate delivery method; avoidance of breastfeeding

Question 3

Explain how the CD4 count determines survival in a HIV patient

Answer 3

• With CD4 Counts ≥500 cells/ml for >5 Years ( similar to general pop.)
• Those with low nadir CD4 have shorter life expectancy and higher rates of malignancy, infection, and CV disease

Question 4

What does AIDS stand for

Answer 4

Acquired immune deficiency syndrome

Question 5

What does HIV stand for

Answer 5

Human immunodeficiency virus

Question 6

What does HAART stand for

Answer 6

Highly active anti-retroviral therapy

Question 7

What does ARV stand for

Answer 7

Anti-retroviral therapy

Question 8

What is the significance of viral load in HIV

Answer 8

• The viral load is the RNA copies/ml
• Aim of therapy is to be ‘undetectable’ (<50cpm)
• Lower VL–> less transmission

Question 9

What is the significance of CD4/T helper cell ( lymphocytes) in HIV

Answer 9

• we can determine the degree of immune damage

- Determine when to start ARV treatment

Question 10

What is the acute seroconversion/ primary HIV infection

Answer 10

• The period of time after acquiring HIV when abs are developing
• Up to 90% of people have symptoms

Question 11

What are the clinical manifestations of primary HIV infection

Answer 11

• Fever,rash, sore throat
• Glandular fever-like illness
• Lymphadenopathy
• Malaise, myalgia,arthralgia, diarrhoea
• Neurological symptoms: meningitis, encephalitis, neuropathy,myelopathy
• Ulceration (oral, ano-genital)

Question 12

State the differential diagnosis of HIV seroconversion

Answer 12

• Infectious mononucleosis
• cytomegalovirus
• rubella
• Herpes
• Adenovirus
• Hep B/C
• Flu
• secondary syphillis
• streptococcal pharyngitis
• Toxoplasmosis
• Lymphoma or leukaemia

Question 13

State the characteristics of asymptomatic HIV infection

Answer 13

• Infected, infectious but not unwell
• CD4 count is steady or falls slowly
• Rate of viral replication is slow
• Stage of infection at which approx 50% are diagnosed

Question 14

State the characteristics of symptomatic HIV disease

Answer 14

As CD4 count declines patients develop ‘non-specific’ HIV related symptoms:

• Fevers
• Night sweats
• Weight loss
• Diarrhoea

‘Simple’ conditions become recurrent/ harder to treat

• Skin conditions ( seborrheic dermatitis, eczema, psoriasis)
• Chest infections
• Herpes, candid, HPV
• Cervical dysplasia
• Molloscum contagiosum

Question 15

State some AIDS defining illnesses

Answer 15

Terminal stage of HIV infection
Advanced disease with severe immunosuppression
CD4 count< 200
-seborrheic dermatitis
-Oral candida 
-Oral hairy leukoplakia 
-Pneumocystis pneumonia 
-Cervical cancer
-Kaposi's sarcoma
-Lymphoma
-TB
-Mycobacterium avium complex 
-Cryptococcosis 
-Progressive multifocal leucoencephalopathy (PML)
-Toxoplasmosis

Question 16

Explain the role of HIV reservoirs

Answer 16

• In the early stages of HIV infection, a reservoir of HIV infected cells is established
• This reservoir consists of long lived- cells( eg memory T cells) that defy clearance with treatment
• Early treatment, eg around the time of seroconversion, or within 3 months, might affect the size of the reservoir
• Agents( histone deacetylase inhibitors ( HDACi eg vorinostat ) are used to ‘ wake up the viral reservoir’ and then attack with eg immunotherapeutic HIV vaccines