Immune Def 1 Flashcards
immunodef definition
what is an essential part of the innate immune system
-neutrophils (polymorphonuclear leukocytes)
3 functions of neutrophils
- chemotaxis, secretes C3a and C5a and chemokines
- participates in opsonization via IgG and C3b
- phagocytosis
defects of neutrophil function
- neutropenia: inadequate neutrophils eg patients receiving chemotherapy
- defective opsinization (IgG or c3b def)
- defective neutrophil killing (bactericidal) activity (chronic granulomatous disease)
once a neutrophils phagocytooses its target, how does it get rid of it?
-lysosomal granules in the neutrophil cytoplasm collide with the phagosome and release their grnaules containing numerous bactericidal enzymes and superoxide anions
chronic grnaulomatous disease
- genetics
- cause
- symptoms
- X linked
- inability to generate superoxide anion due to a defect in cytochrome b and NADPH oxidase
- recurrent infection with abcesses of skin, lymph nodes and other organs, and chronic granulomas
LFA-1 def
- characterization
- result of problem
- symptoms
- this is a leukocyte adhesion deficiency
- failure for neutrophis to emigrate out of vessels towards the antigen
- failure of CD8 cells to bind to target cell
- recurrent bact infections
- failure to heal wounds such as the ambilicus
chediak higashi syndrom
- giant lysosomal grnaules
- recurrent infections
- “rocks” in the neutrophils
what are humoral immunodeficiency diseases characterized by?
-what organisms become a problem
- decreased or absent antibodies resulting in recurrent bacterial infection
- common bacteria become a problem suchas streptococci, staphylococci, and pneumococci
x linked agammaglobulinemia
- aka
- genetics
- characterization
- cause
- symtoms
- gel results
- also called brutons agammaglobulinemia
- boys (x linked)
- absent IgG,A, and M
- pre b-cells in marrow but no mature B cells
- absent or very small tonsils and lymph nodes
- mutation of the Btk gene (burtons tyrosine kinase is important for the light chain gene rearrangment)
- recurrent infections with extracelluar pyogenic organisms
management of x linked agamaglobulinemia
- avoid infections where possible
- antibiotics
- intravenous immunoglobulin
igA deficiency
- common 1:700
- many IgA deficient individuals have no problems
- those with an associated IgG2 or igG4 def develop severe respoiratory and gastrointestinal infections
- intravenous gammaglobulin is not usually helpful
what interaction is crucial for class switching
-CD40L on an activated T cell with CD on a B cell with that antigen bound to its MHC class 2
hyper IgM syndrome
- cause
- characterization
- symptoms
- mutation of the CD40L gene
- failure of isotype switching
- patients make only IgM and IgD and cannot switch to IgG,A, or E
- recurrent infections
- no germinal centers
transient hypogammaglobulinemia of childhood
- characterization
- cause
- delay in the production of normal antibodies
- b cells are present just take some time after birth to start producing antibodies
- cause is unknown
