immunodeficiencies

Question 1

what is the pathophys of chronic granulomatous disease?

Answer 1

Mutation in genes encoding for components of NADPH oxidase in phagocytes → inability to generate oxygen free radicals → impaired killing of intracellular microorganisms → slow healing infections and formation of granulomas

Question 2

what is the pathophys of leukocyte adhesion deficiency type 1?

Answer 2

Defective CD18/β2 integrin gene → leukocytes cannot adhere to ligands on blood endothelial cells
Poor leukocyte chemotaxis → leukocytes cannot leave vasculature to site of infection

Question 3

Series of genetic defects that cause defective development of T cells

Answer 3

Severe combined immunodeficiency (SCID)

Question 4

what is X-linked SCID?

Answer 4

γ-chain deficient receptors → immature T cells cannot proliferate in response to IL-7 → no T cells and NK cells

Question 5

what does deficiency in adenosine deaminase (ADA) and purine nucleoside phosphorylase (PNP) lead to?

Answer 5

SCID
accumulation of metabolites that are toxic to lymphocytes

Question 6

what does mutation in CD40L X-linked gene cause?

Answer 6

failure of CD40L expression on activated T cells → defect in isotype swtiching → X-linked hyper-IgM syndrome

Question 7

X-linked lymphoproliferative syndrome (XLP) is caused by a defect in SAP-SLAM signalling which results in…
a. defect in integrin action
b. defect in t cell development
c. defect in antibody isotype switching
d. defect in NK cell management of defective B cells

Answer 7

d. defect in NK cell management of defective B cells