immuno board review

Question 1

defense against organisms that enter the body

inflammation: immune cells (neutrophils), chemical mediators (cytokines)

complement activation

antigen presentation by activation of adaptive immune system

are all examples of what kind of immunity

Answer 1

innate

Question 2

histamine is part of the exudative component of inflammation)

what does histamine do?

Answer 2

vasodilation of arterioles –> blood flow

increased permeability of blood vessels (by producing endothelial gaps in the venules* and arterioles –> a net loss of blood plasma ( exudate high in plasma proteins)

the exudate will provide opsonins (IgG and C3b) and dilutes the bacterial toxins)

Question 3

what does the exudate released by histamine stimulate provide?

Answer 3

opsonins (IgG and C3b)

Question 4

Q on boards

during the first few seconds of inflammation the arterioles will be constricted.

what is this due to?

Answer 4

a neurogenic reflex (pain)

not part of the inflammation

Question 5

lecukocyte migration and extravasation what three steps?

Answer 5

margination

transmigration (diapedesis)

chemotaxis

Question 6

Q on boards

the process of extravasation takes place predominantly through the endothelium of the?

Answer 6

venules

Question 7

integrin is a cell adhesion molecule that promotes _____binding of the leukocytes to the endothelial cells ?

Answer 7

tight binding

Question 8

a pt on corticosteroids. you would expect an increase in what cell in the blood

Answer 8

neutrophils

corticosteriod have a demargination effect on the neutrophils –> inc neutrophil count

Question 9

what chemotaxic agents stimulate leukocyte movement (neutrophils)

Answer 9

C5a

IL-8

LT- B4

Kallikrein

Question 10

ON THE BOARDS

neonate presenting with

omphalitis, pneumonia, or periotonitis

what is the pathology of this disease

Answer 10

Leukocyte adhesion def (LAD)

leukocytosis but no abscess formation bc granulocytes cannot migrate to the site of infection

two substypes

1. mut in B chain of CD18 Integrin subunit (required for tight binding of neutrophils to endothelium)
2. dec selectin required for rolling neutrophils along endothelial surface

Question 11

what disease ahs a dec CD18 integrin subunit

Answer 11

Leukocyte adhesion def type 1

Question 12

TB produces _____ that inhibits leukocyte migration –> chronic granuloma formation

Answer 12

cord factor

Question 13

what type of lesion will form if a splinter is left in the skin?

Answer 13

granuloma or chronic inflammation

or collection of cells (macrophages w. fibrobast)

Question 14

Q on boards

what cells are found in the skin and have branched projections

Answer 14

dendritic cells

Question 15

involving neutrophilic respiratory burst pathway

can H2O2 kill microbes

Answer 15

.false

it cannot kill microbes

only hypochloride can.

Question 16

major basic protein ​is secreted by eosinophils and

has a good cytotoxic effect on ______ vs a minor activity on ?

this is a o2 independent microbial kiling mechanism

Answer 16

strong effect on Parasites

minor activity on bacteria

Question 17

opsonization.

is the process of binding the antigen by ?

Answer 17

IgG and or C3b to facillitate pahgocytosis.

how? they cover the negative charge on the antigen by binding to Fc and CR1 receptors on the antigen surface.

Question 18

Q on boards

a pt with gram negative sepsis. the endotoxin (lipopolysaccharide) Lipid A will activate what on macrophages to induce sepsis?

Answer 18

toll like receptor 4 (TLR4) on the macrophages to induce

IL-1 –> fever

TNF a and NO –> vasodilation, hypotension

Question 19

what is responsible for gram - sepsis

Answer 19

TNF -a

Question 20

on the boards

chronic granulomatous disease (NADPH oxidase def) is caused by?

Answer 20

persistence of chronic inflammation.

this was the answer.

Question 21

CGD

has what type of inheritance

what is the main problem in this disease

pts have increased susceptibility to what organisms?

Answer 21

defect of NADPH oxidase –> dec reactive oxygen species (superoxide) and dec resiratory burst in neutrophils

X linked

Catase + organism. (staph, pseudomonas Aspergillus, nocardia, )

Question 22

pt with CGD

nitroblue tetrazolium dye will show?

dihydrorhodamine (flow cytometry) test will show?

treatment?

Answer 22

nitroblue tetrazolium dye reduction test fails to turn blue

abnormal dihydrorhodamine shows dec green fluorescence

tx: interferon gamma

Question 23

triad of symptoms

1. recurrent pyogenic infections (by staphylococci and streptococci)
2. partial albinism (** oculocutaneous albinism)

3. peripheral neuropathy. –> progess to neurodegeneration, infiltrative lymphohistiocytosis.

horizontal nystagmus

peripheral blood smear shows giant granules in graunlocytes and platelets (impaired emptying phagocytic cells)

whats the cause of this disease

Answer 23

lysosomal trafficking regulator gene (LYST)

microtubule dysfunction in phagosome-lysosome fusion

Question 24

what disease

autosomal recessive

recurrent acute/chronic infections with no pus formation (bc lack of leukocyte recruitment

no signs of inflammation except .fever

no umbilical cord stump rejection

Answer 24

leukocyte adhesion def.

Question 25

**C3b opsonatization** stimulates **opsonization** def --\> recurrent pyogenic sinus and respiratory infections (**from encapsulated organisms)** Which one is not opsonized? A. strept pneumonia B. N. Mengingitis C. N. Gonorrhea

Answer 25

**N gonorrheae** **bc it is not encapsulated.**

Question 26

**C3a** **C5a** stimulate?

Answer 26

**anaphylaxis**

Question 27

(C5b, C6-9) + C3 --\> (membrane attack complex) --\> .perforation of the pathogen cell membrane ---\> **cytolysis** def leads to\>

Answer 27

**inc risk of disseminated Neisseria bacteremia**

Question 28

**C1 esterase inhibitor def --?** classic finding:edema of skin (periorbitial) + mucosal surfaces

Answer 28

**Hereditary angioedema** ## Footnote characterized by dec C4 levels. **avoid ACE inhibitors.**

Question 29

**C55 and CD59** def --\>

Answer 29

**Paroxysmal nocturnal hemoglobinuria**

Question 30

what do CD55 and CD59 do

Answer 30

**block C3** and **C5 convertase**

Question 31

what falls under Acquired (specific) immunity

Answer 31

**humoral immune response** **-** mediated by **B** lymphocytes --\> **antibodies (Ig M, ...)** **Cell-mediated immune rxn** **-**it is the main function of **T .**cells; in addition to regulation of antibody production by B cells

Question 32

Question on boards pt with **recurrent Bacterial infections** problem is B cells where are they located in LN ? Spleen?

Answer 32

LN: the outer cortex in **germinal center** of the **ocrtical follicles** **spleen: lymphoid follicles** of the **white** pulp

Question 33

on the boards pt with recurrent fungal infections. what cell is def **T cells** where are they located in the LN and Spleen

Answer 33

LN: **paracortical area** Spleen **periarteriolar lymphoid sheaths** in the white pulp

Question 34

immunoglobulin will perform their functions by

Answer 34

**opsonization** (by coating the microorganism to make them susceptible to phagocytosis **complement cascade activation.** --\> microbial cell wall lysis (IgG and IgM) **neutralization -** preventing bacterial adherence to mucosa.

Question 35

on the boards **6-8 month old infant** w/ **recurrent bacterial infections** **large tonsils** and **palpable lymph nodes** labs: **high** Ig**M** , low levels of other types of Ig \*\*what the cause?

Answer 35

**CD-40 ligand** on **helper T cells** is **absent** diagnosis **hyper-IgM syndrome**

Question 36

what immunoglobulin is a monomer in circulation but when secreted it forms a **dimer** linked by **J chains**

Answer 36

**IgA**

Question 37

what immunoglobulin is the **primary immune response** and **complement fixation**

Answer 37

**IgM**

Question 38

on the boards (immunoglobulin pearls **IgM** In the serum of a **neonate** this indicates what? and what is the most likely cause?

Answer 38

indicates **intrauterine infection** look for **congenital rubella.** since Ig**M** cant cross the placenta like (igG)

Question 39

which immunodeficiency disease has **low IgM** **elvated IgA** and **normal IgE** (maybe elevated) pt have inc susceptibility to pyogenic infections, **eczema,** and **thrombocytopenia** --\> petechiae and bleeding

Answer 39

**wiskott-Aldrich syndrome**

Question 40

wiskott Aldirhc syndrome pts have an increase risk for what malignancies what is the treatment

Answer 40

**leukemia** and **lymphoma** tx: bone marrow transplantation

Question 41

what is the TCR complex?

Answer 41

**TCR + CD3** know that CD3 is seen in **both** CD4 and CD8 T cells. and is involved in the transduction of signals into the T cell after bidning TCR with antigen.

Question 42

Q on boards in **positive selection** in the thymic .**cortex** **thymocytes** (immature T cell) that do not bind to the MHC/antigen complex will die via what mechanism?

Answer 42

**lack of growth signals ​**

Question 43

Q on boards where do lymphocytes have both CD 4 and CD8 expression

Answer 43

immature T cells in the **cortex of the thymus.**

Question 44

during **negative selection** in the thymus **thymocytes** that strongly interact with self antigen will be removed by?

Answer 44

**apoptosis**

Question 45

Q if pt has mutation of the **FAS** protein this will block the process of **apoptosis** this puts the pt at increased risk for?

Answer 45

**autoimmune disorders** bc no apoptosis in negative selection in thymus --\> persistent auto -reactive lymphocytes

Question 46

Interleukins are mainly secreted by?

Answer 46

**helper CD4+ T lymphocytes**

Question 47

garanteed question on boards **IL-1** is secreted by **macrophages** and acts on the ? --\> **fever** **(** like **IL-6)**

Answer 47

il-1 acts on the **hypothalamus**

Question 48

**know for boards** **IL-4 --\>** **IL-5 --\>**

Answer 48

IL-4 ---\> **IgE production** IL-5 ---\> **inc eosinophils** and **inc IgA production**

Question 49

example how IL-6 can cause fever

Answer 49

**il-6** --\> able to cross **BBB** --\> inc synthesis of **PGE2** in the **hypothalamus --\> changing the body temps setpoint**