Immunology

Question 1

Medullary region of lymph nodes contains what types of cells?

Answer 1

Reticular cells

Macrophages

Question 2

What is present on blood smear in a person with splenectomy?

Answer 2

Howell jolly bodies
Target cells
Thrombocytosis

Question 3

What are the features of the innate immune system?

Answer 3

Fast, Nonspecific, No memory

PMNs, Macs, NKs, Dendritic cells, Complement

Question 4

MHC 1 features?

Answer 4

HLA [A, B ,C]
On all nucleated cells expect RBCs
heavy chain + B2 microglobulin

Question 5

MHC II features?

Answer 5

HLA [DP, DQ, DR]
Only Ag presenting cells
2 alpha chains 2 beta chains

Question 6

What are the associations with HLA-B27?

Answer 6

Psoriasis
Ankylosing spondylitis
IBD
Reiters syndrome

Question 7

What HLA is associated with Celiac disease?

Answer 7

HLA DQ2/8

Question 8

What HLA is associated with MS, SLE, and Goodpasteurs?

Answer 8

HLA DR2

*Notice its an MHC II cause caused by antibodies

Question 9

What HLA is associated with DM and Graves? RA? Pernicious anemia?

Answer 9

DM= HLA DR3
RA = HLA DR4
Per = HLA DR5

Question 10

What cells use perforins and granzymes to induce apoptosis in virally infected cells and Tumor cells in the absence of MHC 1 on the surface?

Answer 10

NK cells

Question 11

What cytokines activate NK cells?

Answer 11

IL-2
IL-12
IFN- alpha & Beta

Question 12

WHat are the key features of the Innate immune system that “recognize” pathogens?

Answer 12

TLRs

PAMPs (LPS, ssRNA, flagella)

Question 13

What is the mechanism of Antigen loading onto MHC 1?

Answer 13

Antigen “PEPTIDES” loaded in RER after delivery via TAP transporter

Question 14

What is the mechanism of Antigen loading onto MCH II?

Answer 14

Loaded following Invariant chain in acidified Endosome

Question 15

What is the co-stimulatory signal required to activate T cells?

Answer 15

B7 on APC —> CD28 on Tcell

**B7 on macs and dendritic cells

Question 16

What is the costimulatory signal that induces B cell class switching?

Answer 16

CD40 L on Tcell –> CD40r on Bcells

Question 17

What cytokines do Th1 secrete?

Answer 17

IFN gamma to activate Macrophages and CTLs

Question 18

What cytokines do Th2 secrete?

Answer 18

IL-4 –> IgE
IL-5–> IgA + Eosinophils
IL-6 –> Acute phase proteins
IL-13 –> Igs

Question 19

What is the macrophage Lymphocyte reaction needed for Granulomas?

Answer 19

Macs release IL-12 –> T-cells differentiate into Th1 cells.
Th1 secrete IFN g to activate macs

Question 20

What is the function of Regulatory Tcells?

Answer 20

Maintain specific immune tolerance by suppressing CD4/ CD8 cells
*Once activated= Anti-inflammatory
secrete IL-10, TGFbeta

Question 21

What are the Surface markers for Treg cells?

Answer 21

CD3
CD4
***CD25

Question 22

What are the anti-inflammatory cytokines?

Answer 22

IL-10

TGF beta

Question 23

What are the Fab and Fc portions of Antibodies?

Answer 23

Fab = Antigen binding site, Variable site, Ag specificity site
Fc= Constant, Complements binding site

Question 24

What processes cause antibody diversity?

Answer 24

Recombination of VJ regions
Heavy chain rearrangement
Somatic hypermutation= Germinal centers
Addition of Nucleotides to DNA during recombination

Question 25

What are the features of IgG?

Answer 25

Most abundant Ig Crosses placenta Opsonizes bacteria Neutralizes toxins/ viruses

Question 26

What are the features of IgA?

Answer 26

Monomer in circulation Dimer when Secreted Crosses epithelial cells via TRANSCYTOSIS

Question 27

Features of IgE?

Answer 27

Binds Mast cells and basophils Immunity against worms via Eosinophils LOWEST concentration in serum due to rapid binding via Mast cells

Question 28

What are the Acute phase reactants "Unregulated" during inflammation?

Answer 28

Serum amyloid A CRP= opsonin, fixes complement Ferritin= sequesters IRON Fibrinogen= Coagulation, endo repair, ESR Hepcidin= Prevents release of IRON by ferritin

Question 29

What Acute phase reactants are "Down-regulated" during inflammation?

Answer 29

Albumin= Conserve AAs | Transferrin

Question 30

What activates the Activators for Complement: Classical pathway Alternative pathway Lectin pathway

Answer 30

``` Classical= IgM + IgG Alternative = Microbe Surface Lectin = Mannose ```

Question 31

What are the functions of: C3a C3b C5a

Answer 31

C3a + C5a = Anaphylaxis C3b = Opsonin + Clear ICs C5a = PMN chemotactic

Question 32

What inhibit Complement activation on self cells?

Answer 32

DAF | C1 esterase inhibitor

Question 33

What is the flow of the Alternative complement system?

Answer 33

C3b + B/D --> C3 convertase --> C3b (C5 convertase)

Question 34

What is the flow of the Lectin pathway?

Answer 34

MBL-> C1 complex -> C4b {C3 convertase}

Question 35

What is the flow of the Classical pathway?

Answer 35

C1 complex -> C2b + C4b= C3 convertase

Question 36

What is the main difference btwn Classical and Alternative pathways?

Answer 36

``` Classical = C1 + C2 + C4 Alternative = C3 + B/D ```

Question 37

Low C4 levels will be seen when what complement pathway is activated?

Answer 37

Classical == IgM + IgG

Question 38

C1 esterase inhibitor deficiency?

Answer 38

Hereditary Angioedema | ACE CI

Question 39

C3 deficiency?

Answer 39

Recurrent Pyogenic sinus infections | Inc susceptibility to T3HS rxn

Question 40

GPI anchored DAF def?

Answer 40

PNH

Question 41

What are the functions of IL-1?

Answer 41

Fever | Activate endothelial cells to express adhesion molecules

Question 42

What are the functions of IL-12?

Answer 42

Induces Th1 differentiation | Activates NKs

Question 43

What are the functions of TNF alpha?

Answer 43

Septic shock Endothelial activation Leukocyte recruitment Vascular leakage

Question 44

What cytokine function like GM-CSF?

Answer 44

IL-3

Question 45

What cytokine suppresses Th2, and has Antiviral & antiTumor properties via NK cell activation?

Answer 45

IFN gamma

Question 46

What are the functions of IL-5?

Answer 46

IgA | Eosinophil growth and differentiation

Question 47

What are the mechanism of IFN actions?

Answer 47

Induce Ribonuclease that inhibit viral protein synthesis Degrade viral mRNA {alpha & beta} Gamma= increases MHC I + II expression & activates NK cells

Question 48

What cells express CD28?

Answer 48

T cells

Question 49

What cells express CD21? What is this a receptor for?

Answer 49

B cells | EBV receptor

Question 50

What cells express CD14?

Answer 50

Macs | **also have Fc & C3b receptors

Question 51

What cells express CD56 and CD16?

Answer 51

NK cells

Question 52

What is the unique marker for NK cells?

Answer 52

CD56

Question 53

What bacteria classically undergo Antigen variation?

Answer 53

Borrelia = relapsing fever gonorrhea (PILUS protein) Salmonella (flagella) Trypanosomes

Question 54

Endotoxins and LPS directly stimulate?

Answer 54

Macrophages via CD14 NO Th cells involvement **Unlike SuperAgs that activate T cell receptors

Question 55

For what can Passive immunity be given?

Answer 55

Tetanus Botulinum HBV Rabies

Question 56

Features of T1 HS?

Answer 56

IgE + immediate Asthma, hay fever, drugs Mast cells = First release Histamine/ Eos chemotactic Late; release PGs and LTs

Question 57

What are the 3 mechanisms of T2HS cell destruction?

Answer 57

Opsonization Complement ADCC via NK cells

Question 58

Direct vs Indirect coombs?

Answer 58

``` Direct= Detect Abs that HAVE bound pts cells Indirect= Detect Abs that CAN bind pt serum ```

Question 59

Serum sickness and arthus reactions are examples of what?

Answer 59

T3HS Serum sickness= 5days post Foreign protein causing Abs to form and bind it. Deposit in tissue and activate Complement Arthus= Ag-Ab complexes in Skin= necrosis

Question 60

Blood transfusion reactions symptoms & Rx: Allergic reaction?

Answer 60

Urticaria Wheezing Fever Rx: Anti-histamines

Question 61

Blood transfusion reactions symptoms & Rx: Anaphylactic reaction?

Answer 61

Dyspnea = Bronchospasms Hypotension Respiratory arrest/ shock

Question 62

Blood transfusion reactions symptoms & Rx: Febrile nonhemolytic rxn?

Answer 62

Fever headache chills Flushing

Question 63

Blood transfusion reactions symptoms & Rx: Acute hemolytic rxn?

Answer 63

``` Hypotension Tachypnea Tachycardia Flank pain Hemoglobulinemia Jaundice ```

Question 64

``` Auto-antibodies and diseases: Anti-CCP Anti-Topo1 Anti-mitochondrial Anti-endomysial Anti-Transglutaminase Anti-Jo1/SRP/ Mi-2 Anti-smooth muscle Anti-glutamate Decarboxylase ```

Answer 64

``` CCP= RA Topo1= Scleroderma Mito= Primary biliary cirrhosis Endomysial= Celiac Transglutaminase= Celiac Jo1/ SRP/ Mi2= Polymyositis/ Dermatomyositis Smooth muscle= AI hepatitis Glutamate dc= T1 DM ```

Question 65

Pt that has recurrent TB or disseminated TB has what def?

Answer 65

IL-12 or INF gamma

Question 66

Pt with coarse face, Staph abscesses, Eczema, and Increased IgE?

Answer 66

Jobs syndrome = Hyper IgE * *Th1 cells fail to produce IFN gamma * PMNs inability to respond to chemotactic

Question 67

Pt with cerebellar defect, spider angiomas, IgA def and increase AFP?

Answer 67

Ataxia-telangiectasia= DNA repair defect

Question 68

Pt with thrombocytopenia, recurrent infections, and Eczema. What is the underlying cause of his symptoms? What is seen on Ig differential?

Answer 68

Wiskott aldrich = T cells unable to reorganize **ACTIN cytoskeleton **Inc IgE + IgA but Low IgM

Question 69

Pt with neutrophilia but inability to form pus has what defect?

Answer 69

Leukocyte adhesion def = Def= LFA1 Integrins or CD18 **Delayed umbilical cord seperation

Question 70

Pt with a recent kidney transplant presents with rash, jaundice, diarrhea, and hepatosplenomegaly. what is the dx?

Answer 70

Graft vs Host

Question 71

Main mediators of Rejection: Hyperacute Acute Chronic

Answer 71

``` Hyperacute= Abs (occlude BVs, necrosis) Acute= CTLs (vasculitis, infiltrate) Chronic= CTL recog MHC1 presentation as nonself (FIBROSIS, vascular damage, Irreversible) ```