Lecture 30: Immunodeficiencies

Question 1

Define immunodeficiency.

Answer 1

• Result from the absence or failure of normal function, of one or more immune system function
• >100 immunodeficiency diseases. Range from mild-severe. Different symptoms depending on which part of the immune system is affected
• Characterisation of where mutations occur enables greater understanding of the molecular basis for immune function

Question 2

Recall two ccategories of immunodeficiency.

Answer 2

Question 3

Recall the diagnosis of immunodeficiencies.

Answer 3

Question 4

Recall the major types of primary ID.

Answer 4

Question 5

Recall the casue of XLA.

Answer 5

Question 6

Describe XLA susceptibility and treatment.

Answer 6

Question 7

Describe HIGM Syndrome.

Answer 7

• Family of genetic disorders associated with an absence of isotype switching (No IgG, IgA)
• Compensatory increase in IgM in serum
• Patients have increased susceptibility to bacterial infections (particularly Streptococci and Pneumocystis carinii)
• Treatment is routine intravenous Ig therapy

Question 8

Describe the cause of X-linked HIGM.

Answer 8

Question 9

Describe the cause of HIGM Type 2.

Answer 9

Question 10

Recall other examples of B cell ID.

Answer 10

Question 11

Describe Wiskott-Aldrich Syndrome.

Answer 11

Question 12

_________ is required for the formation of Immunological synapse

Answer 12

WAS protein is required for the formation of Immunological synapse

Question 13

Describe Familial Hemophagocytic Lymphohistiocytosis.

Answer 13

Question 14

Describe Epidermodysplasia verruciformis.

Answer 14

Question 15

Descrie DiGeorges syndrome.

Answer 15

Question 16

Describe Bare Lymphocyte Syndrome II

Answer 16

• Mutations in any one of four genes that control expression of MHC class II genes - Class II transactivator (CIITA), RFXANK, RFX5, RFXAP
• Little or no MHC class II expression on surface of B cells, macrophages or dendritic cells
• Consequence of no MHC class II expression
  
  • Failed positive selection in the thymus – reduced helper T cells, reduced antigen presentation
• Patients have severe and recurrent infections

Question 17

Describe SCID.

Answer 17

Question 18

Describe X-linked SCID.

Answer 18

• Mutation in CD132 is most common reason for SCID (accounts for ~50 % of cases)
• Patients lack functional B, T and NK cells
• Infants suffer increased susceptibility to array of opportunistic infections
  
  • Candida albicans, Pneumocystis carinii, parainfluenza, cytomegalovirus, EBV, mycobacterium

Question 19

Recall 3 genes that are mutated on autosomal recessive SCID.

Answer 19

Question 20

Recall effects of mutation in JAK3.

Answer 20

Question 21

Recall effects of mutation in ADA.

Answer 21

Question 22

Recall effects on mutation of RAG.

Answer 22

Question 23

Recall the Summary of T and B cell immunodeficiencies

Answer 23

Question 24

Recall the treatments of immunodeficiency.

Answer 24