Primary Immune Deficiency

Question 1

What are the causes of primary and secondary immunodeficiency?

Answer 1

1. Primary - immunological problem (usually genetic)

2. Secondary - myeloma, CLL, nephrotic syndrome, protein losing enteropathy, AIDS, immunosuppressive medications.

Question 2

What is the criteria for diagnosing a primary immune deficiency?

Answer 2

1. 8 or more ear infectious in 1 year
2. 2 or more serious sinus infections in 1 year
3. 2 or more months on Abx with little/no effect
4. 2 or more pneumonias in 1 year
5. Failure to thrive in an infant
6. Recurrent, deep skin, or organ abscesses
7. Persistent thrush in mouth/on skin, after age 1
8. Need for IV Abx to clear infection
9. 2 or more deep seated infections
10. Family history of PID

Question 3

What is this describing?

1. Loss of ability to make Abs, early adulthood.
2. IgG deficiency, recurrent pulmonary and GI infections.

Answer 3

Common variable immune deficiency

Question 4

What is the investigation and management of common variable immune deficiency?

Answer 4

1. IgG reduced, pneumococcal and haemophilus Abs not present.
2. IV Ig then switch to SC

Question 5

What is this describing?

Failure to control complement. Recurrent cutaneous and submucosal swelling, laryngeal oedema, autosomal dominant.

Answer 5

C1 esterase inhibitor deficiency/hereditary angioedema

Question 6

What is the investigation and management of C1 esterase inhibitor deficiency/hereditary angioedema?

Answer 6

1. FHx, no relationship to allergens, no urticaria, low C4, low C1 esterase inhibitor levels.
2. FFP if diagnosis unclear, treat established cases with C1 esterase inhibitor replacement.

Question 7

What is this describing and how is it treated?

X-linked recessive, defect in Bruton’s tyrosine kinase required for B cell maturation. Recurrent bacterial infections.

Answer 7

1. X-linked agammaglobulinaemia

2. IV Igs

Question 8

What is this describing and how is it treated?
Absent adaptive immunity, paediatric emergency. Early infancy, failure to thrive, diarrhoea, frequent infection (CMV, VZV, PCP, candidiasis). Low lymphocytes in 90%.

Answer 8

1. Severe combined immune deficiency

2. Specialist, treat infection, no live vaccines, bone marrow transplant definitive.

Question 9

What is this describing and how is it treated?

Recurrent pneumonias and abscesses. Negative nitroblue-terazolium test.

Answer 9

1. Chronic granulomatous disease

2. Prophylactic Abx and IFNy