Immunodeficiencies

Question 1

B cell deficiency

Answer 1

Ig levels decreased
skin test normal
germinal centers decreased
primary extracellular bacteria

Question 2

T cell deficiency

Answer 2

Ig levels normal or reduced
skin test decreased
normal follicles but decrease in paracortical regions
viruses, intracellular bacteria, fungi

Question 3

Bruton’s agammaglobinemia

Answer 3

absence of mature B cells
little serum immunoglobulin
mutations in B cell tyrosine kinase
X linked disease, males

Question 4

common variable immunodeficiency

Answer 4

caused by intrinsic B cell defects of unknown mechanism

treat with monthly gamma globulin shots and antibiotic therapy

Question 5

selective IgA deficiency

Answer 5

inherited or acquired, common

IgM can compensate for missing IgA

Question 6

X linked hyper IgM syndrome

Answer 6

inherited deficiency of CD40L on T cells, CD40 not engaged on B cells, no isotype switching

Question 7

hyper IgM syndrome type 2

Answer 7

inherited mutation in the gene activation induced cytidine deaminase, prevents isotype switching

Question 8

DiGeorge Syndrome

Answer 8

T cells severely decreased

immunoglobulin levels near normal

Question 9

SCID

Answer 9

failure of B and T cells to develop from bone marrow stem cells

due to deficiency of adenosine deaminase

deoxyadenosine and deoxy ATP accumulate and are toxic to lymphocytes

Question 10

purine nucleotide phosphorylase deficiency

Answer 10

type of SCID

accumulation of toxic nucleotide metabolites

Question 11

RAG1 and RAG2 deficiency

Answer 11

failure of VDJ rearrangement in immunoglobulin and T cell receptor genes due to mutations in RAG 1 and 2

Question 12

X linked SCID

Answer 12

mutation in common gamma chain for cytokine receptors IL2,4,7,9,15

lymphocytes cant develop properly

Question 13

chronic granulomatous disease

Answer 13

defect in NADPH oxidase

neutrophils cant produce superoxide anion during respiratory burst

Question 14

myeloperoxidase deficiency

Answer 14

decreased or absent myeloperoxidase

normally produces HOCl from H2O2 and chloride, HOCl is antibacterial & antifungal

Question 15

Chediak Higashi Syndrome

Answer 15

recurrent bacterial infections due to large cytoplasmic granules in neutrophils from fusing of lysosomes

decreased ability to kill microbes

Question 16

leukocyte adhesion deficiency

Answer 16

defect in B chain of LFA-1 and Mac-1 adhesion molecules

neutrophils cant adhere to endothelial cells for extravasation

Question 17

severe congenital neutropenia

mutation in elastase enzyme

Answer 17

dominant or recessive trait
low levels of neutrophils
bone marrow transplant needed

Question 18

cyclic neutropenia

mutation in elastase enzyme

Answer 18

dominant

fluctuating neutrophils

Question 19

Wiskott Aldrich Syndrome

defective cytosolic protein involved in actin cytoskeleton of bone marrow cells

Answer 19

Triad= immunodeficiency, eczema, thrombocytopenia

x linked disorder

Question 20

ataxia telangiectasia

Answer 20

autosomal recessive
defect in ATM protein
loss of ability to coordinate muscles, vascular lesions, and increased incidence of tumors