Immunohematology-blood banking-Dr Fung Flashcards
What is this:
the collection, processing, storage and distribution of whole blood and apheresis derived blood and blood components.
Blood banking
occurs at blood collection facility or blood center
What is this:
pretransfusion and compatibility testing, post-manufacture processing. Occurs predominantly at a hospital
Transfusion medicine
What is the major test to test for blood type?
agglutination
What is this:
used for blood bank testing
- Immediate spin (i.e. take patients blood and mix it with IgM antibodies and check for agglutination)
-again at 37 celcius
-IAT phase (detects RBCs coated with IgG +/- complement)
Tube testing
What antibodies are significant in tube testing?
IgG (not IgM)
In tube testing, if there is not agglutination where will the fluid be in the tube?
At the bottom (more agglutination towards the top)
(blank) determines in vivo agglutination
(blank) determines in vitro agglutination
DAT
IAT
The (blank) reflects in vivo antibody sensitization of erythrocytes. Erythrocytes are washed to remove any unbound antibodies, and anti-IgG AHG reagent is then added. IgG antibodies cannot cause direct erythrocyte agglutination, but if the erythrocytes are coated with IgG antibodies, the AHG reagent will cause them to agglutinate. This test can also be performed using anti-complement AHG reagent. If IgG antibodies are present, they can be eluted off the erythrocytes for specificity determination
DAT
direct agglutination test
The (blank) is used to detect the presence of IgG antibodies in serum (in vitro sensitization). Reagent erythrocytes are incubated in the presence of serum that potentially contains antibodies. If antibodies are present, they bind to their target antigens on the reagent erythrocytes. After the incubation period the erythrocytes are washed to remove unbound antibodies. Anti-IgG AHG reagent is added and will cause IgG-coated erythrocytes to agglutinate
IAT (indirect agglutination test)
What is this:
defined as “an inherited character of the red cell surface detected by a specific alloantibody”
blood group
Blood groups are organized into (blank)
blood group systems
What are blood group systems?
represents a single gene or cluster of two or more closely linked homologous genes
Currently there are (blank) recognized blood groups
297 belong to 33 systems
339
WHat are the proteins, glycoproteins and glycolipids found on RBCs?
ABO Rh secretory (Se,se) Lewis Kell Duffy Kid I MNS P
Why are blood groups clinically significant?
- hemoloytic tranfusion reaction
- hemolytic disease of the newborn/fetus
What are the most signif antibodies detection?
Require previous exposure
IgG
warm reactive (37 celcius)
WHat are the most insignif antibodies for blood group detection?
Naturally occuring
IgM
cold reaction (below 37 celcius)
(blank) cant cross the placenta this is why only IgG can give you hemolytic disease of the newborn
IgM
How to you get the ABO blood system?
you have type 1 and type 2 chains
What are type I chains?
glycoproteins and glycolipids free-floating in secretions and plasma
What are type 2 chains?
glycolipid and glycoprotein antigens bound to red cell membrane
Type I chains are found in the (blank)
saliva
(blank) gene modifies type I chains to produce H antigen (substance)
Se
(blank) gene modifies type 2 chains to produce H antigen (substance)
H
H antigen is further modified to make (blank) and (blank)
A antigen
B antigen
The (blank) antigen has no further modification of H antigen
O
What is the most important blood group?
ABO blood system
How is the genotype of the ABO blood system determined?
by three codominant alleles on the long arm of chromosome 9
What chromosome allows for the determination of the ABO blood system?
chromosome 9
Antigens are also carried on (Blank), (blank), (blank), (blank), (blank) (blank) and (blank)
platelets, endothelium, kidney, heart, lung, bowel, and pancreas
ABO antigens are present on fetal RBCs by (Blank) weeks of gestation and reach adult level by age 4
6
What are the most common blood types in caucasions?
A and O
What is the most common blood type in AA?
O
What are the most common blood types in asian?
O
WHat are the most common blood types in Native Americans?
O
What is bombay blood type?
Lack of H, A, and B antigens due to lack of H and Se genes (hh,sese)
(blank) are clinically significant and naturally occuring.
Antibodies
What do ABO antibodies do?
activate complement
immediate intravascular HTR
When do you get ABO antibodies?
appear at 4 months of age and reach adult levels at age 10
T or F
ABO antibodies may disappear with age
T
What are the three ABO antibodies?
Anti-A
Anti-B
Anti A,B
What will Group A blood make?
anti-B IgM antibodies that react strongly at body temperatures (37 celcius)
What will Group B blood make?
anti-A IgM antibodies that react strongly at body temperatures
What will Group O blood make?
Anti-A and anti-B IgG antibodies that react best at body temperatures
anti A, B IgG against A or B cells
Mild HDFN (most common)
How do you confirm a blood type?
with forward and reverse typing
Forward-(ex. A group agglutinates with anti-A)
reverse (ex. A group agglutinates with B cells)
When you are talking about positive or negative when discussing blood type you are referring to (blank)
Rh system
What is the second most important blood group?
Rh system
What are the 2 genes in the Rh system?
RHD (D/-)
RHCE (C/c, E/e)
RH(blank) makes most antibodies, then C and E
D
RH(blank) is very immunogenic, 80% of D-neg make anti-D
D
If you dont have your RH compatible, what will happen>
you will get hemolytic transfusion RXN with extravascular hemolysis
You can get severe hemolytic disease fetus newborn with (blank) and (blank)
anti-d and anti-c
You cant get mild HDFN with (blank) (blank) and (Blank)
anti-C, anti-D, anti E
ABO antibodies (need/dont need) previous exposure
dont need
RH antibodies (need/dont need) previous exposure
need
how do you typically get prototypical HDFN?
Not first pregnancy, unless mom was previously transfused
D-neg with D+ baby
How do you prevent HDFN with RH?
RHIG (commercially prepared anti-D)
WHen do you get anti-D and to whom?
D-neg females at 28 weeks gestation
D-neg females ≤72 hrs. of D+ baby’s birth
D-neg females with pregnancy complications or invasive procedure (amniocentesis, etc..)
WHen should you not give RhIG (anti-D)?
D-neg female who already has anti-D
D+ females
D-neg mom with D-neg baby
What is the RhIG dosage?
One full dose vial (300µg) per 30 ml of D+ whole blood
One full dose vial (300µg) per 15ml D+ RBCs
How do you determine percentage of fetal-maternal hemorrhage?
Fetal blood screen: qualitative
Kleihauer-Betke; quantitiative but poorly reproducible
Flow cytometry-quantitative and more accurate
Wha tis the KB percent?
the number of fetal cells in the adult blood
How do you calculate the amount of rhogam to give (RhIG)?
you take KB% and mutiply it by blood volume then divide by 30! then if the number after the decimal is less than 5 round up once, if more than 5 round up twice
What is the lewis system?
similiar to ABO system
In secretors Leb most common
in non-secretors LeA most common
Insignificant, naturally occuring, cold-reacting IgM antibodies
What is the MNS system?
Consists of M N S antignes
Which part of the MNS system is this:
insignificant, naturally occuring, cold-reacting IgM
Anti-M and anti-N
Which part of the MNS system is this:
Significant, exposure requiring, warm-reacting IgG
Anti-S, anti-s, anti-U
What part of the MNS system is this:
rarely associated with severe HDFN
Anti-M