Secondary Immunodeficiency and HIV Infection ✅ Flashcards
By what mechanisms can secondary immunodeficiencies be acquired?
- Immunosuppressive drugs
- Hyposplenism
- Chronic illness
What is sufficient in the management of many patients with secondary immunodeficiency?
General advice on preventing exposure to infection
What effect does optimising management of the underlying disorder have on secondary immunodeficiencies?
It can significantly reduce the risk of infection
What may be required in the treatment of more severe secondary immunodeficiencies?
- Prophylactic antimicrobials
- Judicious use of vaccines
- Immunoglobulin therapy
Give an example of when the development of secondary immunodeficiency can be anticipated?
Elective splenectomy
What can be done in situations where the development of secondary immunodeficiency can be anticipated?
Planned vaccination can be administered prior to immunosuppression
Why is the number of people living with HIV increasing?
- Ongoing transmission
- Improving survival
What is improving the survival from HIV?
Increasing access to anti-retroviral drugs
How many children in the UK are living with HIV?
Around 900
How many new cases of HIV are identified in children in the UK annually?
50-60
Why are the numbers of children being diagnosed with HIV in the UK low?
Due to the success of universal HIV screening in pregnancy and prevention of mother-to-child transmission
Of what age are most children with HIV in the UK?
Adolescence
What is focused on with care of children with HIV in the UK?
- Adherence
- Complex resistance
- Long-term drug toxicity
- Sexual and mental health
- Transition to adult services
What testing is done when an infant is born to a HIV positive mother?
PCR testing
Is antibody testing a child born to a HIV positive mother useful?
No
Why is antibody testing for HIV in a child born to a HIV positive mother not useful?
As HIV IgG antibody is placental transferred
What is the limitation of a HIV PCR at birth?
It has a low sensitivity, and does not rule out infection
Why is the sensitivity of a HIV PCR low at birth?
Due to low viral load
What is the sensitivity of HIV PCR testing by 3 months of age?
> 99%
When is HIV infection deemed to be very unlikely in an infant born to a HIV positive mother?
- Two negative PCRs, one after 3 months
- Two negative antibody tests if <12 months
- One negative antibody test after 18 months
