primary immunodeficiency Flashcards
primary immunodeficiencies
- genetic mutation that may occur at any phase of the immune response
- can lead to autoimmunity and malignancy
- inheritance does play a rule
- most present in childhood
maternally transmitted IgG can/cannot mask immunodeficiency up until about 6 months of age
can
agammaglobulinemia
- caused by defects in B cell development
- germinal center formation in these patients is defective (no peyers patch, lymph nodes, spleen, tonsils)
- defect in b cell tyrosine kinase pre B cells cannot mature
t/f most primary immunodeficiencies are due to antibody deficiencies
true
t/f agammaglobulinemas are x-linked and autosomal recessive
true
x-linked agammaglobulinemias account for _____ % of agammaglobulinemias
85
agammaglobilnemia is also known as
Brutons
b cell tyrosine kinase
required for transducing signals from the pre-B cell receptor downstream to signal B cell maturation
x-linked agammaglobulinemia has approximately ____ % with positive family history
50%
which Ig is decreased in x-linked agammaglobulinemia
IgG , < 100 mg/dl
t/f people with agammaglobulinemia have normal t cell number and function
true
hyper-IgM syndrome
defects in B cell isotype switching collectively lead to a group of disorders called Hyper-IgM syndrome
t/f people with hyper-IgM syndrome express normal numbers of B cells but express low levels of IgM and elevated levels of IgG, IgE, and IgA
false
people with hyper-IgM syndrome express normal numbers of B cells but express high levels of IgM and low levels of IgG, IgE, and IgA
IgA deficiency
- most common primary immunodeficiency
- usually asymptomatic
- less than 5-7 mg/dl
Common Variable Immunodeficiency (CVID)
- second most frequent primary immunodeficient disease in humans
- most prevalent PID in adults
- recurrent infections
- absent or impaired specific antibody responses
- reduced serum of IgG IgA, and or IgM
specific antibody deficiency
- recurrent sinoulmonary deficiency
- normal IgG, IgA, and IgM
- normal B cell number and normal T cell number and function
- impaired vaccine response to polysaccharides
- impaired antibody response to natural infection with encapsulated bacteria
encapsulated organisms
Some Killers Have Pretty Nice Capsules streptococcus pneumoniae and pyogens Staph aureus Klebsiella Haemophilus influenzae Pseudomonas Neisseria Cryptococcus
Transient Hypogammaglobulinemia of Infancy
- recurrent sinopulmonary infections
- low IgG but NORMAL specific antibodies
- normal lymphocyte number and function
- onset 6 months resolved by age 4
Transient Hypogammaglobulinemia of Infancy onset at _____ months of age and resolve by age _____
6; 4
two ways to check specific antibody production
- protein constituents (diphtheria and tetanus)
2. polysaccharides (isohemagglutinins) need to check blood type first
t-cell dysfunction clinical characteristics
infections with intracellular microorganisms
- failure to thrive (cannot grow)
- anergy
- increased B-cell malignancies
- thrush
- eczema
omenn syndrome
- leaky SCID
- hypomorphic mutations usually in RAG genes
- low to normal number of t -cells
- exudative erythroderma
- lymphadenopathy
- hepatosplenomegaly
- failure to thrive
- elevated IgE
SCID x-linked
can affect t cell development
DiGeorge Syndrome
defect in embryogenesis 3rd and 4th pharyngeal pouches
- most have chromosome 22 deletino
- clinical features: dysmorphic facies, hypocalcemia, congenital heart disease
- depressed T cell immunity
- partial (thymic hypoplasia) versus complete (thymic aplasia)
