9 - Type II Hypersensitivity

Question 1

How is type II hypersensitivity defined?

Answer 1

destruction of normall tissue cells by antibody igg or igm with activation of complement or antibody dependant cell cytotoxicityw

Question 2

hat are some common examples of type 2 hypersensitivity

Answer 2

hemolytic anemia of newborns
penicillin induced anemia
some autoimmune dz
blood transfusion reactions

Question 3

What is the difference between agglutination and rouleaux?

Answer 3

Rouleaux are orderly linear stacks of RBCs, whereas RBC agglutination is formed by grapelike RBC aggregates. To aid in differentiating between rouleaux and agglutination, a saline dilution test is useful.

Question 4

What is ACD (acid citrate dextrose) solution?

Answer 4

An anticoagulant and energy source
there are ready to go human blood collection packs
and sigma chemical co

Question 5

What is the following formula for ACD solution?

Answer 5

Trisodium citrate 22.0g
citric acid (monohydrate) 8.0g
Dextrose (monohydrate0 24.6 g
Distilled water to make up to 1L
for each 100ml of blood, need 15ml of ACD solution (pH 5.0)

Question 6

What are blood group antigens?

Answer 6

Part of the structure of RBC’s
molecules expressed on the surface of RBC’s - not involved in antigen processing
Name often starts w/ species code and EA (erythrocyte antigen) followed by letter/number denoting order of discovery
EX DEA(dog erythrocyte antigen) 1.1 (first allele of antigen 1)

Question 7

What are some transfution reaction causes?

Answer 7

A recipient may contain pre-existing antibodies as a result of previous exposure - to blood (prior transfusions or pregnancies), to vx’s (some contain animal tissue), and to similar antigents thru diet
dietary risk is species dependant such as in cattle
significant clin signs if infusing lg amounts of incompatible blood into sensitized patient

Question 8

what does sensitized mean?

Answer 8

has pre-existing antibody

Question 9

What is the mechanism of transfusion reaction causes?

Answer 9

Mechanism: pre-existing antibody binds to erythrocyte antigens
by aglutination, opsonization, complement activation results in hemolysis (free hemoglobin can damage kidneys) and anaphylatoxin release + mast cell degranulation

Question 10

How can we prevent transfusion reactions?

Answer 10

by doing cross matching
most important is donor RBC’s w/ patients serum and look for lysis or agglutination
And less important is donor serum and patient RBC called minor cross match

Question 11

What are some blood transfusion reaction clinical signs?

Answer 11

montior for signs of incompatibility
mild to moderate
- sweating, salivation, diarrhea, vomiting, increased RR + HR, fever
Severe - Shock
Weakness, hyper/hypotension, tachy/bradycardia, dyspnea, DIC, Collapse, death (arrhythmia or apnea)

Question 12

How should we respond when we see a transfusion reaction?

Answer 12

STOP transfusion
ALERT DVM
maintain urine prod via IV fluids and diuretics
meds with diphenhydramine and +/- epinephrine

Question 13

What is the recovery phase of transfusion reaction

Answer 13

Hemoglobulin eventually converted to bilirubin
icterus of mucosae and sclera

Question 14

What is useful information in terms of blood transfusions in cattle?

Answer 14

MANY blood types and some have preformed Ab’s against foreign RBC antigens
- Ab seen in cattle have had no previous blood transfusions
1st transfusion lasts d’s-wks
repeated transfusions have shorter RBC lifespan

Question 15

DO dogs have preformed Ab’s against foreign antigens?

Answer 15

no

Question 16

How many RBC antigens do dogs have? What are some of their antigens?

Answer 16

Many
DEA 1, strong antigen - causes most significant problems, several labs make card test to detect it
DEA 1.1 is subgroup is major concern with DEA 1 dogs
DEA 1.1 + k9’s are universal recipients
DEA 1.1 - k9’s are universal donors

Question 17

What happens if a DEA 1.1 + dog recieves blood from DEA 1.1 + and DEA 1.1 - dog?

Answer 17

Both + and - are unlikely to be a problem

Meaning DEA 1.1 + are universal recipients and DEA 1.1 - are universal donors

Question 18

What happens if we transfuse a dEA 1.1 neg dog with positive blood?

Answer 18

First transfusion is free
transfusion reactions on subsequent transfusions
potential problems in puppies if pregnant (neonatal iseoerythrolysis)
recommended that always cross match on subsequent transfusions and in breed dogs

Question 19

Does Ag testing for strong Ag prevent: problems on 1st transfusions? on subsequent transfusions?

Answer 19

on 1st trans: yes
on subsequent: yes + sm risk of incompatibilities from minor Ag’s

Question 20

Does cross matching first transfusion prevent problems: on first transfusions? on subsequent transfusions?

Answer 20

1st trans: yes
subsequent: no + may be incompatible on second transfusion even though compatible on first

Question 21

How many blood groups do horses have? Do they have any preformed antibodies? Is there a risk of reactions?

Answer 21

Many blood groups, only 2 important
no preformed Ab unless previously exposed to antigenic RBC’s or sensitized thru Vx’
Same risk as in dogs except multiparous pregnant mares who have a higher risk

Question 22

What is important information about blood transfusion in cats?

Answer 22

3 blood types - A, B, and AB
About 99% of DSH/DLH in NA are type A
Purebreeds typically have Type B
Type AB is rare <1-6%
Most type B cats possess IgM against Type A antigens bc of alloantibodies
in transfusions RBC half-life of 4-5 wks w/ a donor and recipient match.
if Type B is transfused in Type 3 cat, RBC half-life is only a few days
Type A into Type B, RBC halflife of 1 hr

Question 23

What blood types are the following?
Siamese + burmese, exotics +british SH + cornish/devon rex + and UK cats?

Answer 23

Siamese + burmese - all type A
Exotics, Brit SH, rexes - up to 60^ are type B
UK cats - 40% type A, 60% type B

Question 24

What is the difference btw a mule and a hinny?

Answer 24

Mule: Donkey stallion x Mare
Hinny: Stallion x Donkey mare

Question 25

Which breeds of equines are most commonly affected by neonatal isoerythrolysis?

Answer 25

Common in throroughbreds and standardbred mares that have had several foals (about 0.05-2% foals affected
In mules, 8-10% are affected

Question 26

What are the signs of hemolytic nemia?

Answer 26

mm are pale and later are icteric
may have possible hemoglobinuria via diagnostic
weakness, lethargy, may have possible shock nd death

Question 27

What are some simple tests to do to test for hemolytic anemia?

Answer 27

PCV - mild Hct = 0.15-0.25 L/L or PCV 15-25%
Severe is <15 %
A juandiced foal agglutination test - mares colostrum is combined w/ foals RBC’s, pos agglutination test
test mares blood during pregnancy for rising titers of Ab’s against Aa or Qa Ag’s

Question 28

What are some ways to treat hemolytic anemia in foals?

Answer 28

Prevent/stop colostrum ingestion for at least 36h
ideally, feed colostrum from another mare - as an alternative, and can give serum from an unrelated horse
Oxygen, fluids and electrolytes, antimicrobials
may need a blood transfusion if PCV <15% - convenient source is WASHED RBC’s from dam and can perform by letting RBC settle by gravity

Question 28

What happens with type II drug hypersensitivities? What’s an example of it?

Answer 28

drug or its breakdown products bind to cells making them appear foreign (antigenic)
ex penicillin associated hemolytic anemia in horses

Question 28

How does neonatal isoerytholysis show in cats?

Answer 28

“Fading kitten syndrom”
rare in NA, common in UK
likely seen w/ blood type B queen mating with Type A tom
Type A is dom so Tom(aa or ab), queen (bb) so offspring:
Tom aa - all kittens ab (type A)
If tom ab (kittens ab or bb(type b)
Blood group A offspring at risk of neonat iso from Anti-A antibody in colostrum
chance of dz is sm if Type A queen and Type B tom - Type A cats has less preformed antiB antibody

Question 29

What are the signs of neonatal isoerythrolysis in cats?

Answer 29

anemia, icterus, weakness, hemoglobinuria

Question 30

What do vx’s have to do with type II drug hypersensitivities?

Answer 30

vx grown on tissue
such as cattle killed BVD vx grown on kidney cells
contained potent adjuvant
stimulated anti- MHC Ab production which is transferred to calves in colostrum and caused pancytopenia

Question 31

What is pancytopenia?

Answer 31

A condition in which there is a lower-than-normal number of red and white blood cells and platelets in the blood.

Question 32

In which species is a blood transfusion likely to be successful even if there is no cross matching?

Answer 32

k9 + horses

Question 33

Define type II hypersensitivity

Answer 33

IgG/IgM antibody attacking normal tissue

Question 34

why might a 1-day old foal be severely anemic?

Answer 34

neonatal isoerythrolysis