Immunodeficiencies & infections Flashcards
Most Primary Immunodeficiencies are single gene defects, what are the 3 domains?
1) Ab deficiency due to defect in B cells
2) Cellular due to T cell defect
3) Innate due to phagocytes or complement defect
What about a child’s illness would make you suspect an immunodeficiency?
SPURR:
- Severe
- Persistant
- Unusual
- Recurrent
- Runs in family
What infections arise from Ab deficiencies?
Recurrent resp bacterial infections incl Pneumococcus & H influenzae
What type of infections arise from T cell deficiencies?
Opportunistic infections incl Pneumocytic Jiroveccii pneumonia (PCP) & CMV pneumonia
What type of infections would you expect to see in a phagocyte defect?
Staph aureus –> Sepsis, skin inf & deep organ abscesses
Aspergillus –> Lung, bones & brain inf
What could you do if you suspect Primary Immunodeficiencies?
Ab and immunoglobulins –> Ab tests & measuring immune response to vaccination with common pathogens
T cell? –> Diff WCC &immunophenotyping
Complement for neisseria meningitis
NBT- nitroblue test
HIV test
FBC
What’s the main secondary immunodeficiency?
HIV/AIDS
How would you spot HIV/aIDS?
Recurrent/disseminated VZV/HSV
Opportunistic Inf e.g. CMV pneumonia or PCP
Recurrent RTIs & Persistant oral thrush
Erythematous popular rash, generalized lymphadenopathy & FTT/developmental delay
Invasive fungal infections e.g. Candida Albicans or Aspergillus Fumigatus are often a presenting symptoms of Primary immunodeficiency. What else would cause one?
- Neutropenia e.g. leukaemia/chemo
- Neonates (immature immunity)
- Broadspec Abx and/or abdo surgery
And primary immunodeficiency
When would you be likely to develop secondary immunodeficiency?
- Acquired diseases/ Treatments which affect the immune system : HIV, Steroid use, malignancy treatment
What would you expect to see in complement deficiencies?
Sepsis
N. meningitis
What is done to prevent Paediatric HIV?
- Maternal screening
In mothers with high viral load: - ART for mothers
- Prophylaxis for babies postnatally
