Immunodeficiency Flashcards
When should an immune evaluation be performed?
When have two or more bacterial infections; unusual organisms are found; have a persistent infection
What are some things other than immune deficiency that could cause persistent/unusual infections?
Burns (skin breakdown), ciliary immobility, CF
What is the most common immunodeficiency? Is it always symptomatic?
Selective IgA deficiency- may be asymptomatic
How is SCID inherited?
x-linked and autosomal recessive
How is SCID treated? What happens if no treatment takes place?
BM transplant- no treatment then death
What is the most common cause of SCID? Why is this so severe?
interleukin receptor gamma chain defect- effects the gamma chain in an array of cytokine receptors including IL-2R, IL-7R, IL-4R, IL-21R
What is missing in SCID? Why are they missing?
T cells and B cells- missing because cytokine receptors have a defect so can’t get cytokine binding
The misfunction of what cells can lead to immunodeficiency?
B cells (humoral), T cells (cell-mediated), phagocytes (cell-mediated), complement (cell-mediated)
What type of immunodeficiency is x-linked agammaglobulinemia?
Humoral immunodeficiency
What causes the lack of B cells seen in x-linked agammaglobulinemia?
Mutation in Bruton’s tyrosine kinase (BTK)- needed for B cell maturation
What are some quantitative measures that would show you a patient has humoral immunodeficiency?
Higher quantity of IgM, inability to produce a high titer even after vaccination
What would CD40L deficiency cause?
B cells can’t be activated; humoral immunodeficiency, hypogammaglobulinemia with a lot IgM because can’t class switch; inability to activate macrophages
What would lymph nodes look like when there’s a CD40L deficiency?
No germinal centers; no B cell class switching of affinity maturation
When a patient is complement deficient, what types of infections are they more susceptible to?
Neisseria
A patient with SCID is given a Tetanus vaccine. What is the response?
Nothing happens- not harmful, but also not really beneficial
What is a neutrophil defect known as?
Chronic granulomatous disease
Why do granulomas form in chronic granulomatous disease?
Neutrophils are present but not functional; so they need extra help from activated macrophages
A phagocyte deficiency makes the patient more susceptible to what kinds of infections?
Catalase positive bacteria (Staph)
What are the abnormalities seen with DeGeorge syndrome?
Abnormal development of the 3rd and 4th pharyngeal pouches, resulting in thymic hypoplasia/aplasia and hypoparathyroidism which leads to heart disease
Those with DeGeorge are more susceptible to what kinds of infections?
Viral and fungal disease
How is DeGeorge treated? Is a BM transplant effective?
Thymic transplant- BM transplant isn’t effective because still doesn’t have a thymus that T cells can mature in
