Immuno4 0519FA

Question 1

Bruton’s agammaglobulinemia

Answer 1

B cell disorder.
X-linked recessive.
more in Boys.

defect in BTK tyrosine kinase gene blocks pro-B cells from forming pre-B cells.

Question 2

presentation of Bruton’s agammaglobulinemia

Answer 2

recurrent BACTERIAL infxs after 6 mos (decreased maternal IgG) due to opsonization defect

Question 3

labs in Bruton’s agammaglobulinemia

Answer 3

normal pro-B.
decreased B maturation.
decreased #B cells.
decreased all classes of Ig.

Question 4

hyper-IgM syndrome

Answer 4

B cell disorder.

defective CD40L on helper T cells = inability to class switch.

Question 5

presentation of hyper-IgM syndrome

Answer 5

severe pyogenic infxs early in life

Question 6

labs in hyper-IgM syndrome

Answer 6

INCREASED IgM.

greatly decreased IgG, A, E.

Question 7

selective Ig deficiency

Answer 7

B cell disorder.

defect in isotype switching = deficiency in specific class of Igs.

Question 8

presentation of selective Ig deficiency

Answer 8

sinus and lung infx.
milk allergies, diarrhea.
ANAPHYLAXIS on exposure to blood products with IgA.

Question 9

labs in selective Ig deficiency

Answer 9

IgA deficiency most common.
failure to mature into plasma cells.
decreased secretory IgA.

Question 10

common variable immunodeficiency (CVID)

Answer 10

B cell disorder.

defect in B cell maturation due to various causes.

Question 11

presentation of CVID

Answer 11

can be acquired age 20-30.

increased risk of:
AUTOIMMUNE disease.
lymphoma.
sinopulmonary infx.

Question 12

labs in CVID

Answer 12

NORMAL number of B cells.

decreased plasma cells and Ig.

Question 13

thymic aplasia (DiGeorge syndrome)

Answer 13

T cell disorder.

22q11 deletion.
failure to develop 3rd and 4th pharyngeal pouches.

Question 14

presentation of thymic aplasia (DiGeorge syndrome)

Answer 14

tetany (hypocalcemia).
recurrent viral/fungal infxs.
congenital heart and great vessel defects.

Question 15

labs in thymic aplasia (DiGeorge syndrome)

Answer 15

failure of thymus and parathyroids to develop = decreased T cells, PTH, and serum calcium.

ABSENT THYMIC SHADOW on CXR.

Question 16

IL-12 receptor deficiency

Answer 16

T cell disorder.

decreased Th1 response.

Question 17

presentation of IL-12 receptor deficiency

Answer 17

disseminated mycobacterial infxs

Question 18

labs in IL-12 receptor deficiency

Answer 18

decreased IFN-gamma

Question 19

hyper-IgE syndrome (Job’s syndrome)

Answer 19

T cell disorder.

Th cells fail to produce IFN-g = inability of neutrophils to respond to chemotactic stimuli.

Question 20

presentation of hyper-IgE syndrome (Job’s syndrome)

Answer 20

FATED:
coarse Facies.
cold, noninflamed staph Abscesses.
retained primary Teeth.
increased IgE.
Derm problems (eczema).

Question 21

chronic mucocutaneous candidiasis

Answer 21

T cell disorder.

T cell dysfunction leading to Candida albicans infx of skin and mucous membs.

Question 22

severe combined immunodeficiency (SCID)

Answer 22

B and T cell disorder.

various types:

1. defective IL-2 receptor: most common type. X-linked.
2. adenosine deaminase deficiency.
3. failure to synthesize MHC II Ags.

Question 23

SCID presentation

Answer 23

recurrent bacterial, viral, fungal, AND protozoal infxs.

ABSENT THYMIC SHADOW.
absent germinal centers (LN).
absent B cells in peripheral smear.

Question 24

SCID labs

Answer 24

1. decrease IL-2 receptor = decrease T cell activation.

2. increased adenosine with ADA deficiency = toxic to B and T cells (decreased dNTP, decreased DNA synth)

Question 25

SCID TX

Answer 25

BM transplant (no allograft rejection)

Question 26

ataxia-telangiectasia

Answer 26

B and T cell disorder. auto recessive defect in ATM gene that codes for DNA repair enzymes.

Question 27

presentation of ataxia-telangiectasia

Answer 27

TRIAD: 1. cerebellar defects (ataxia). 2. spider angiomas/oculocutaneous lesions (telangiectasias). 3. IgA deficiency. * DNA is hypersensitive to ionizing radiation. * increased sinopulmonary infxs and malignancy.

Question 28

Wiskott-Aldrich syndrome

Answer 28

B and T cell disorder. X-linked recessive defect. PROGRESSIVE DELETION of B and T cells.

Question 29

presentation of Wiskott-Aldrich syndrome

Answer 29

TRIAD (TIE): 1. Thrombocytopenic purpura. 2. Infxs (encapsulated orgs). 3. Eczema.

Question 30

labs in Wiskott-Aldrich syndrome

Answer 30

increased IgE, IgA. | decreased IgM.

Question 31

leukocyte adhesion deficiency type I

Answer 31

phagocyte dysfunction. defect in LFA-1 integrin (CD18) protein on phagocytes.

Question 32

presentation of leukocyte adhesion deficiency type I

Answer 32

recurrent bacterial infxs (skin). absent pus formation. poor wound healing. delayed separation of umbilical cord. NEUTROPHILIA.

Question 33

Chediak-Higashi syndrome

Answer 33

phagocyte dysfunction. auto recessive defect in lysosomal trafficking regulator gene (LYST) = microtubule dysfunction in phagosome-lysosome fusion.

Question 34

presentation of Chediak-Higashi syndrome

Answer 34

recurrent pyogenic infx by staphylococcus, streptococcus. partial albinism. peripheral neuropathy.

Question 35

chronic granulomatous disease (CGD)

Answer 35

phagocyte dysfunction. lack of NADPH oxidase = decreased ROS (superoxide) and absent resp burst in neutrophils

Question 36

presentation of CGD

Answer 36

increased susceptibility to CATALASE-POSITIVE organisms (S.aureus, E.coli, Aspergillus)

Question 37

landmark lab in CGD

Answer 37

negative Nitroblue tetrazolium dye reduction test

Question 38

autograft

Answer 38

from self

Question 39

syngeneic graft

Answer 39

from identical twin or clone

Question 40

allograft

Answer 40

from nonidentical indiv of same species

Question 41

xenograft

Answer 41

from different species

Question 42

hyperacute transplant rejection

Answer 42

within minutes. | Ab-mediated (type II) due to PREFORMED anti-donor Abs in transplant recipient.

Question 43

features of hyperacute transplant rejection

Answer 43

occlusion of graft vessels (acute thrombosis) causing ischemia and necrosis

Question 44

acute transplant rejection

Answer 44

weeks later. | cell-mediated due to cytotoxic T cells reacting against foreign MHCs.

Question 45

acute transplant rejection is reversible with...?

Answer 45

immunosuppressants (cyclosporine, OKT3). try to prevent with calcineurin inhibitors and corticosteroids.

Question 46

features of acute transplant rejection

Answer 46

vasculitis of graft vessels with dense interstitial LYMPHOCYTIC infiltrate. decreased organ function.

Question 47

chronic transplant rejection

Answer 47

months to years. nonself MHC I is perceived by cytotoxic T cells as self MHC I presenting a nonself Ag. may involve B cell sensitization. NOT reversible.

Question 48

features of chronic transplant rejection

Answer 48

T cell and Ab-mediated vascular damage: OBLITERATIVE vascular fibrosis. fibrosis of graft tissue and bld vessels.

Question 49

graft vs. host disease (GVHD)

Answer 49

onset varies. grafted immunocompetent T cells proliferate in the irradiated immunocompromised host and reject cells with "foreign" proteins, thus causing severe organ dysfunction.

Question 50

features of GVHD

Answer 50

maculopapular rash. jaundice. hepatosplenomegaly. diarrhea.

Question 51

GVHD occurs most often with what types of transplants?

Answer 51

bone marrow and liver | organs rich in lymphocytes

Question 52

GVHD is potentially beneficial in what kind of transplant?

Answer 52

bone marrow

Question 53

prevention of GVHD

Answer 53

HLA matching. | anti-thymocyte immune globulin to remove donor T cells.