Primary Immunodeficiency Flashcards
When should you suspect primary immunodeficiency?
Infections that are
- Serious
- Persistent
- Unusual
- Recurrent
What points should you ask in a history if suspecting immunodeficiency?
Infection history
- site
- frequency
- need for admission
- PO/IV abx
Immunisation history
Family history
- infections
- autoimmunity
- neonatal death
What are the categories of primary immunodeficiency?
Antibody (B cells)
Combined (T cells)
Complement
Phagocyte
What are the types of B cell disorders?
Selective IgA deficiency
Common variable immunodeficiency
X-linked agammaglobulinaemia
What is the presentation of selective IgA deficiency?
Recurrent mucous membrane infections
What is the immunoglobulin picture in selective IgA deficiency?
Low IgA
Normal IgM, IgG
What causes common variable immuodeficiency?
Genetic mutation in B cell components
What is the presentation of common variable immunodeficiency?
Recurrent respiratory tract infections
Unable to develop immunity
What is the immunoglobulin picture in common variable immunodeficiency?
Low IgG
Low IgA
+/- low IgM
How is common variable immunodeficiency managed?
Replace immunoglobulins
What is the inheritance of x-linked agammaglobulinaemia?
X-linked recessive
What age does x-linked agammaglobulinaemia present?
6 months
What is the presentation of x-linked agammaglobulinaema?
Recurrent infections
No tonsils
What is the immunoglobulin picture in x-linked agammaglobulinaemia?
Low IgG
Low IgM
Low IgA
What is SCID?
Severe combined immunodeficiency
What age does SCID present?
First few months
How does SCID present?
Persistent severe diarrhoea
Failure to thrive
Opportunistic infections
Unwell after live vaccinations
What causes SCID?
Mutation in common gamma chain on X chromosome that code for interleukin receptors on T and B cells
What is the inheritance pattern of SCID?
X-linked recessive
What is the management of SCID?
Treat underlying infections
Sterile environment
Hemopoietic stem cell transplant
What are T cell disorders?
DiGeorge syndrome
Purine nucleoside phosphorylase deficiency
Ataxic telangiectasia
What is DiGeorge syndrome?
22q11 deletion
How does DiGeorge syndrome cause T cell problems?
Incomplete thymus development -> inability to create T cells
What is the inheritance pattern of PNP deficiency?
Autosomal recessive
