Primary Immunodeficiencies

Question 1

What are the most common forms?

Answer 1

Antibody Disorderes

Then Phagocyte and T Cell Disorders

Question 2

What would make you think of a PID?

Answer 2

If the patient (usually a kid) gets infections that are abnormally:

• Severe (needs hospital or IV abx)
• Persistent
• Unusual organism
• Recurrent
• Run in the family

Question 3

In general how are we gonna manage PIDs?

Answer 3

Prevent and treat infections

Genetic Counselling & prenatal diagnosis

Target the cause where possible:

• Immunoglobulin Substitution for B cell disorders
• Gene Therapy (e.g. for SCID genes)
• Stem Cell Transplant e.g. CGD
• Thymus Transplant for DiGeorge

Question 4

What infections are likely in a phagocyte disorder?

Answer 4

Staph Aureus

Aspergillus in the lung, bone or brain

Question 5

What condition occurs in neutrophil dysfunction

Answer 5

Chronic Granulomatous Disease

Question 6

What conditions occur in Complement deficiencies?

Answer 6

Neisseria Meningitidis Infection

Hereditary Angioedema

Question 7

What is hereditary Angioedema?

Answer 7

A c1-inhibitor deficiency of autosomal dominant inheritance –> Inflammation & oedema

Question 8

How does Hereditary Angioedema present?

Answer 8

Recurrent painless, non-putting, non-pruritic, non-erythematous swelling in subcutaneous tissues, intestines & Oropharynx

Question 9

How do you treat Hereditary Angioedema?

Answer 9

Emergency management of the airway obstruction or abdo pain

C1-inhibitor infusion OR fresh frozen plasma

Question 10

What are SCID genes?

Answer 10

Severe Combined Immunodeficiencies

A set of genetic mutations that cause fatal combined immunodeficiencies in the innate immune system

You need a stem cell transplant to survive

Question 11

What kind of infections are you likely to get from a B cell deficiency?

Answer 11

Recurrent resp bacterial infections e.g. Strep Pneumoniae & H influenzae

Question 12

What infections can you get from a T cell disorder?

Answer 12

Opportunistic Infections e.g. Pneumocystic Jirovecii or CMV

Question 13

What’s the most common T cell “syndrome” deficiency?

Answer 13

Digeorge Syndrome aka 22q11 deletion

Question 14

How does 22q11 present?

Answer 14

Congenital Cardiac Abnormalities
Palatal defects
Immunodeficiency (Thymus hypoplasia)
Learning disabilities
Characteristic Facies 
Developmental Disability

Question 15

What is thymus aplasia likely to cause in 22q11 deletion syndrome?

Answer 15

Reccurent RTIs in infancy

Autoimmune Phenomena:

• Anaemia/thrombocytopenia- JIA
• Raynaud’s
• Thyroid disease

Question 16

How do we treat someone with 22q11 deletion syndrome?

Answer 16

Gotta transplant that thymus

Question 17

Invasive fungal infections are a hallmark of PID. What type is likely with CD4, neutrophil or Phagocyte disorders?

Answer 17

CD4 defct –> Cryptococcus or pneumocystis

Neutrophil –> ASpergillus

Phagocyte –> Candia