Type II and III Hypersensitivity Reactions

Question 1

how is type II reaction stimulated?

Answer 1

binding of Ab to cell surface Ag, initiating cytotoxicity

Question 2

how is type III reaction stimulated

Answer 2

soluble Ag-Ab complexes deposited in tissues

Question 3

what is ABO incompatibility?

Answer 3

Ab against RBC antigen binds and mediates killing via complement or ADCC (type II)

Question 4

what does blood transfusion reaction cause?

Answer 4

systemic inflammation and RBC lysis

Question 5

what is erythtroblastosis fetalis?

Answer 5

a hemolytic disease of a newborn, where a Rh+ is born to a Rh- mother, the 1st baby is fine but the 2nd time, mother has Ab against Rh from 1st pregnancy. the anti Rh-Ab or cells cross placenta and maternal Ab attach fetal RBC

Question 6

how to treat erythroblastosis fetalis?

Answer 6

treat mother with Ab to Rh (RhoGAM) right after 1st birth

Question 7

what is autoimmune hemolytic anemia?

Answer 7

autoantibodies attach RBC that are carrying foreign substances (like drug metabolites, microbial Ag), and immune system just sees the Ab bound to “foreign Ag” on a cell, stimulates ADCC.

Question 8

early sx autoimmune hemolytic anemia?

Answer 8

SOB and pale skin

Question 9

what could cause autoimmune hemolytic anemia?

Answer 9

1. mycoplasma pneumonia infection

2. drug reactions to ACE inhibitors or sulfa-trimethoprim

Question 10

how does mycoplasma pneumonia cause autoimmune hemolytic anemia?

Answer 10

induces Ab that cross react with RBC antigens (classic hemolytic anemia)

Question 11

how do drug reactions causes autoimmune hemolytic anemia

Answer 11

drug binds to RBC surface and Ab against the drug binds and causes RBC lysis

Question 12

what is goodpasture’s nephritis?

Answer 12

anti-glomerular basement membrane disease (anti-GBM disease) that causes severe illness

Question 13

what happens in goodpasture nephritis?

Answer 13

Ab bind to basement membranes of the kidneys and lungs and activate complement

Question 14

how to diagnose anti-GBM?

Answer 14

blood in urine, foamy urine, swelling in legs, HBP

urinalysis, blood test, CXR, kidney Bx

Question 15

treatment of anti-GBM?

Answer 15

oral immunosuppressive drugs like cyclophosphamide and corticosteroids

Question 16

cause of myasthenia gravis?

Answer 16

production of auto-Ab to acetyl choline receptor (AchR) that causes weakness of muscles responsible for breathing and moving face, eyes, arms, legs.

Question 17

diagnose MG?

Answer 17

ptosis, weakness, blood test looking for auto-Ab

Question 18

treatment for MG

Answer 18

acetylcholinesterase inhibitor (donepezil), immunosuppressive therapies, immunomodulary (IVIG)

Question 19

massive infiltration of what cell type occurs during Type III?

Answer 19

neutrophils

Question 20

what is the localized effect of type III reactions?

Answer 20

arthus reaction that causes vasculitis

Question 21

what is vasculitis

Answer 21

rupture of blood vessels and hemorrhage

Question 22

what is a cause of vasculitis?

Answer 22

injections of Ig against diptheria and tetanus toxins, or immunizations of humans with animal serum (gets worse with each inoculation)

Question 23

what is the systemic effect of type III reactions?

Answer 23

immune complex deposition

Question 24

what triggers immune complex formation?

Answer 24

any kind of Ag can be the trigger

Question 25

what does deposition of the complexes cause?

Answer 25

1. activation of complement 2. release of anaphylotoxins from complement pathways (c3a, c5a) 3. inflammatory damage to the tissues

Question 26

normal body response to immune complexes

Answer 26

PMN and macrophages bind to immune complexes via FcR (IgG) and phagocytize the complexes

Question 27

abnormal body response to immune complexes

Answer 27

unable to phagocytize, so immune complexes cause inflammation via complement activation and frustrated phagocytes

Question 28

what are frustrated phagocytes

Answer 28

cells that cannot phagocytize an immune complex degranulate in the area of immune complex deposition and trigger chronic inflammation

Question 29

what occurs if IC deposits in the joints?

Answer 29

arthritis

Question 30

what occurs if IC deposits in the kidneys?

Answer 30

glomerulonephritis, lupus

Question 31

what is serum sickness

Answer 31

when infectious disease is treated with antisera against bacterial toxins like diphtheria, tetanus, botulinum

Question 32

describe the classic manifestation of serum sickness

Answer 32

1. antiserum from animals is injected into humans 2. Ab against animal serum produced 3. fever, arthralgia, lymphadenopathy, rashes/hives seen within hours 4. rupture of BV and hemorrhage

Question 33

what is SSLR

Answer 33

serum sickness like reaction from use of Monoclonal antibodies produced in rodents

Question 34

what causes rheumatic fever?

Answer 34

sequelae from strep A infection, cross reactivity of GAS Ab with heart muscle tissue and the glomerular basement membrane occurs.

Question 35

symptoms of rheumatic fever?

Answer 35

hx of GAS infection, diffuse joint and body pain, swelling of hands and feet, erythematous rash on lower extremities

Question 36

treatment of rheumatic fever

Answer 36

treat GAS!

Question 37

what causes rheumatoid arthritis

Answer 37

autoantibodies specific for IgG and IgM (anti-Ig autoAb) bind to Fc region of normal IgG in the synovial membranes of joints. this activates complement, attracts neutrophils, and causes inflammation

Question 38

treatment for RA

Answer 38

corticosteroids, NSAID, disease modifying antirheumatic drugs (DMARD)

Question 39

what is systemic lupus erythmatosus (SLE)

Answer 39

chronic inflammatory autoimmune response that causes chronic activation of lymphocytes. activation of complement produces C5a, which attracts neutrophils and releases enzymes, causes systemic damage.

Question 40

symptoms of SLE

Answer 40

malar (butterfly) rash, fatigue, wt loss, arthritis of hands., decreased Hb, presence of antinuclear Ab

Question 41

gender differences in SLE

Answer 41

more common in women, more aggressive in men

Question 42

symptoms of glomerulonephritis

Answer 42

puffiness of face upon waking, urine with trace blood, decreased urination, coughing, SOB, HBP, can cause complete kidney failure

Question 43

treatment of glomerulonephritis

Answer 43

decrease protein, salt, K intake diuretics to treat puffiness and swelling take Ca supplements