HRR: congenital immuno I Flashcards
(42 cards)
Do immunodeficiencies impact the innate or adaptive immune system?
Either one!
What are primary immunodeficiencies?
Those that are congenital and from genetic defects.
What are secondary immunodeficiencies?
Acquired increased susceptibility to infection due to things like age, a disease process, toxic exposures, etc.
What is an inborn error of immunity?
Group of rare, inborn disorders of the immune system that result from absent or reduced number or function of immune cells.
What is the issue with inborn errors of immunity?
Risk for recurrent or severe infection, autoimmunity, hyperinflammation, or lymphoproliferation.
Describe a B cell deficiency in general.
Result in absent or reduced follicles and germinal centers in lymph organs (small lymph nodes) and lead to reduced circulating antibodies. Usually results in bacterial infections.
Describe a T cell deficiency generally.
Reduced T cell zones in lymph organs, reduced T cell reactions to antigens, and defective T cell proliferation can all cause this. Makes someone prone to viral and intracellular infections as well as viral related malignancy.
Innate immune deficiencies generally result in…
Severe bacterial infection.
Are men or women more likely to have congenital immune deficiencies?
Men! This is because some are X linked.
What disease categories are examples of defects in lymphocyte maturation?
SCID, B cell only deficiencies (X linked agammaglobulinemia), T cell only deficiencies (DiGeorge).
What disease categories are examples of defects in lymphocyte activation?
Job’s, bare lymphocyte, X linked hyper IgM, common variable immunodeficiency.
What are typical features of B cell defects?
Low Ig, reduced vaccine response.
What types of infections are associated with B cell defects?
Bacterial sinopulmonary infections (bronchitis, pneumonia, sinus infection, ear infection).
What are typical features of T cell infections?
Reduced T cell counts.
What types of infections are associated with T cell defects?
Viral, fungal, intracellular pathogen.
What is X-linked agammaglobulinemia?
A B cell deficiency caused by a defect in bruton’s tyrosine kinase (Btk).
Describe the mechanism of X-linked agammaglobulinemia.
Lack of Btk inhibits signal transduction needed for pre-B cells to become mature B cells, resulting in deficiency.
What is seen in labs with X-linked agammaglobulinemia?
No B cells and antibodies, normal T and NK cells.
What are clinical risks with X-linked agammaglobulinemia?
Recurrent sinopulmonary infections, chronic diarrhea from giardia, autoimmune disorders, chronic enterovirus meningoencephalitis.
What is seen on exam in X-linked agammaglobulinemia?
Small or no tonsils.
How do we treat X-linked agammaglobulinemia?
Lifelong treatment with immunoglobulin therapy.
What is the most common selective antibody deficiency?
IgA.
In IgA defect, what is usually normal?
Heavy chain; what is abnormal varies.
What are clinical phenotypes of IgA deficiency?
May be normal or have increased likelihood of respiratory or GI infection. May also have an increased risk for autoimmune disorders/antibody to IgA and thus may have allergic reaction to IgA positive blood transfusion.
