(L27) Primary Immunodeficiencies Flashcards
What are the types of primary immunodeficiencies?
L27 S4
Innate:
- phagocytosis
- complement
Adaptive:
- B cells (antibodies)
- T cells
- combined T and B cells (CD4+ related)
What are possible indicators of immunodeficiency?
L27 S5
- 8+ ear infections/year
- 2+ sinus infections/year
- 2+ pneumonias/year
- 2+ deep-seated infections or infections in unusual areas
- recurrent abscesses
- need for IV antibiotic therapy
- opportunistic or unusual infections
- family history
Don’t memorize these, just understand why it might be an indicator
What immunodeficiency is infection with bacterial meningitis possibly indicative of?
L27 S7
Complement deficiency
What tests are used to test for T cell defects, humoral immunodeficiency, complement deficiency, and phagocytic disorders?
L27 S8
T cell:
-delayed-type hypersensitivity (DTH) skin test
Humoral immunodeficiency:
- serum IgG, IgM, and IgA
- specific Ab following immunization
Complement:
-hemolytic assay
Phagocytic:
-nitroblue tetrazolium (looks for oxidative activity)
What is adenosine deaminase (ADA) deficiency?
What is its immunophenotype and what Abs are made?
L27 S14
T-, B-, NK- Low Abs (all types)
Autosomal recessive
Enzyme clears deoxyadenosine from purine metabolism which is toxic to lymphocytes
What is purine nucleotide phosphorylase (PNP) deficiency?
What is its immunophenotype and what Abs are made?
L27 S15
T-, B+, NK+/-
Normal Abs
Autosomal recessive
Enzyme clears deoxyguanosine which is toxic to T cells at high levels
What is Artemis deficiency?
What is its immunophenotype and what Abs are made?
L27 S16
T-, B-, NK+ Low Abs (all types)
Autosomal recessive (radiosensitive)
Presents in infancy with diarrhea, candidiasis, and fungal pneumonia.
Artemis gene product involved in ligation of hairpin loops in V(D)J recombination
What is RAG1/RAG2 deficiency?
What is its immunophenotype and what Abs are made?
L27 S17
T-, B-, NK+ Low Abs (all types)
RAG1/RAG2 crucial in V(D)J recombination for TCR and BCR
What is Jak3 deficiency?
What is its immunophenotype and what Abs are made?
L27 S18
T-, B+, NK+ Low Abs (all types)
Causes defect in IL-2 signaling which is required for T cell survival and activity
What is Omenn syndrome?
L27 S17
Due to partial function of RAG1/RAG2
Characterized by:
- severe erytrhoedema
- splenomegaly
- eosinophilia
- high IgE
What is HSCT and how can it be used to treat certain immunodeficiencies?
L27
Hematopoietic stem cell transplant
Can be used in deficiencies where there are genetic defects in immune cells, or their precursors, that derived from bone marrow.
What is primary agammaglobulinemia? What is its immunophenotype and what Abs are made?
L27 S20
T+, B-, NK+ Low Abs (all types)
Caused by arrest of B cell development at pre-B cell resulting in low or absent circulating B cells
X-linked and autosomal recessive variants
What is X-linked Btk kinase deficiency?
What is its immunophenotype and what Abs are made?
L27 S21
T+, B-, NK+ No Abs (all types)
X-linked
Defect in rearrangement of Ig heavy chain in B cells
What IgG subclass deficiencies are there and what are the associated symptoms?
L27 S22
IgG2:
-poor polysaccharide response
IgG4:
-minimal symptoms
What is IgA deficiency?
What is its immunophenotype and what Abs are made?
L27 S24
T+, B+, NK+
No IgA, normal IgG and IgM
Various methods that either result in faulty maturation of IgA secreting plasma cells or formation of anti-IgA IgG