Immunodeficiencies Flashcards
What is the difference between a primary and secondary immunodeficiency?
primary is genetic and can be inherited wile secondary is acquired and is much more common
What is the most common form of primary immunodeficiency?
Antibody deficiencies
What are some signs of humoral immunodeficiency?
Pyogenic infections, frequent viral infections, chronic diarrhea, and susceptible to encapsulated bacteria
What is the immunodeficiency caused by defects in B cell development, defective germinal centers, or underdevelopment of lymphoid tissues?
Agammaglobulinemias
What is the major defect in X-linked agammaglobulinemia?
B cell tyrosine kinase that helps stimulate B cell maturation
Assays for XLA would show what?
- Normal T cell number
- Low B cell
- Low IgG because of no class switching
What are the characteristics of Hyper-IgM syndromes?
- Normal B cell number
- Elevated levels of IgM
- Lower levels of IgA, E, and G
What is the most common defect that leads to Hyper-IgM?
CD40L
Which is the most common primary immunodeficiency?
IgA deficiency
Which is the most common symptomatic primary immunodeficiency?
CVID (Common Variable Immunodeficiency)
What are some characteristics of IgA Deficiency?
- Usually asymptomatic
- Occasional sinopulmonary infections, diarrhea, and autoimmune disease
- Low levels of IgA
What are some characteristics of CVID?
- Reduced IgG, IgA, and/or IgM
- Absent or impaired specific antibody responses with previous vaccines or infections (vaccine to titer to confirm)
- Recurrent infections (sinusitis and pneumonia) as well as malignancies, granulomatous diseases, autoimmune diseases, etc.
What are some characteristics of Specific Antibody Deficiency?
- Recurrent sinopulmonary infections
- Normal B cell and T cell count
- Normal serum Ig levels
- Impaired vaccine response
- Impaired antibody response to encapsulated bacteria
What are the common encapsulated organisms?
Staph aureus Haemophilus influenzae Neisseria meningitidis Pseudomonas aeruginosa Cryptococcus neoformans Klebsiella Streptococcus pyogenes and pneumoniae
What are some characteristics of Transient Hypoglammaglobulinea of Infancy
- Low IgG
- Normal specific antibodies
- Recurrent sinopulmonary infections
- Usually resolves by age 4 (monitor progress)
Lack of T cells cause what type of immunodeficiencies?
Combined immunodeficiencies because helper T cells also regulate B cell antibody synthesis
What is the best way to treat X-linked SCID and RAG deficiency?
Stem cell bone marrow transplant
“Leaky” SCID is another name for what?
Omenn syndrome