Transcript Unit 5F Immunohem PowerPoint

Unit #5F – Clinical
Laboratory Testing –
Basic Immunohematology
Cecile Sanders, M.Ed.,
MLS(ASCP)
Unit #5F – Clinical Laboratory
Testing - Basic
Immunohematology
 Immunohematology
= Blood Banking
 In blood banking, technologists and
technicians must determine blood
groups (types) and other red blood cell
antigens before blood transfusions may
be given.
 Blood grouping is also used in organ
transplantation, questions of paternity,
forensic investigations, and genetic
studies.
Unit #5F – Clinical Laboratory
Testing - Basic
Immunohematology
 Units
or “pints” of blood are “banked”
for use in transfusions to patients that
need blood either because of a blood
loss (accident or surgery, etc.) or
because the patient is unable to make
his own blood (anemia or leukemia, etc.).
Unit #5F – Clinical Laboratory
Testing - Basic
Immunohematology
 Blood
from donors is collected in a
plastic bag and stored in a special
refrigerator until used or until the
blood expires, usually in 42 days.
Unit #5F – Clinical Laboratory
Testing - Basic
Immunohematology
 Most
hospitals obtain donor blood from
processing centers, such as the
American Red Cross. In Austin, the
donor collection and processing center
is the Blood and Tissue Center of
Central Texas, 4300 N Lamar Blvd,
Austin, TX (512) 206-1266
 PLEASE DONATE BLOOD IF YOU CAN!
Unit #5F – Clinical Laboratory
Testing - Basic
Immunohematology
Donated blood can be separated into several
components, depending on the needs of the
medical community.
 Blood may be left as “whole blood” or
separated into red cells, platelets, and plasma.
In this way, several patients can benefit from
one unit of donor blood.
 Visit
http://www.pbs.org/wnet/redgold/basics/blo
odcollection.html for more information on blood

processing and storage.

Unit #5F – Clinical Laboratory
Testing - Basic
Immunohematology
The ABO System
–
–
–
–

Group O = 45%
Group A = 41%
Group B = 10%
Group AB = 4%
ABO grouping is based on the presence of
absence of blood group antigens on red blood
cells. (Review “antigens” and “antibodies” in
Unit#5C under Basic Serology/Immunology, if
needed)
Unit #5F – Clinical Laboratory
Testing - Basic
Immunohematology
 Group
A individuals have A antigens on
their red cells.
 Group B individuals have B antigens on
their red cells.
 Group AB individuals have A AND B
antigens on their red cells.
 Group O individuals have NEITHER A
NOR B antigens on their red cells.
Unit #5F – Clinical Laboratory
Testing - Basic
Immunohematology
 Red
cell antigens are identified by
mixing a person’s red blood cells with
typing serum (Anti-A and Anti-B) and
looking for agglutination. This is called
forward or direct grouping or typing.
 If a person’s red blood cells agglutinate
(clump) when mixed with a typing serum,
they have that antigen on their red
blood cells.
Unit #5F – Clinical Laboratory
Testing - Basic
Immunohematology
 Anti-A
and Anti-B serums are purchased
like this:
Unit #5F – Clinical Laboratory
Testing - Basic
Immunohematology

Forward or direct
blood grouping
Anti-A
Serum
Anti-B
Serum
Blood Group
Agglutination (+)
No agglutination (-)
A
No agglutination (-)
Agglutination (+)
B
Agglutination (+)
Agglutination (+)
AB
No agglutination (-)
No agglutination(-)
O
Unit #5F – Clinical Laboratory
Testing - Basic
Immunohematology
 Pictures
of ABO Blood Grouping/Typing
Unit #5F – Clinical Laboratory
Testing - Basic
Immunohematology
 Humans
have naturally occurring
antibodies in their plasma or serum
against blood antigens they do NOT
have.
 For example: Group A individuals have
Anti-B antibodies; Group B individuals
have Anti-A antibodies.
 Detection of these antibodies is called
reverse or indirect grouping or typing.

Unit #5F – Clinical Laboratory
Testing - Basic
Immunohematology
Reverse or indirect
blood grouping:
Blood Group
Anti-A Abs
Anti-B Abs
A
No
Yes
B
Yes
No
AB
No
No
O
Yes
Yes

Unit #5F – Clinical Laboratory
Testing - Basic
Immunohematology
Blood Group
Antigens and
Antibodies
Summary
Blood Group
Anti-A Serum
Anti-B Serum
A Abs
B Abs
A
+
-
No
Yes
B
-
+
Yes
No
AB
+
+
No
No
O
-
-
Yes
Yes
Unit #5F – Clinical Laboratory
Testing - Basic
Immunohematology
 Group
O packed red blood cells are
sometimes referred to as the “Universal
Donor”. In an emergency, it can be
given to any blood type because the red
cells do not have antigens against which
the patient’s plasma antibodies might
react. Because the blood is “packed”, it
does not have plasma antibodies.
Unit #5F – Clinical Laboratory
Testing - Basic
Immunohematology
 Group
AB is sometimes referred to as
the “Universal Recipient”. In an
emergency, these patients can receive
any blood type because they do not have
any plasma antibodies to react against A
or B antigens.
 However, it is always best to give the
patient group or type specific blood.
Unit #5F – Clinical Laboratory
Testing - Basic
Immunohematology
 Rh
is another antigen that individuals
may have on their red blood cells.
 Another name for Rh factor is D
antigen.
 If a person has the Rh factor (D
antigen) on their red blood cells, they
are called Rh positive.
 If a person does NOT have the Rh
factor (D antigen) on their red blood
cells, they are called Rh negative.
Unit #5F – Clinical Laboratory
Testing - Basic
Immunohematology
 When
a person is blood grouped or
typed, Rh is always determined, in
addition to ABO grouping.
 Rh (D) grouping/typing is also
performed using anti-serum (anti-D),
which is mixed with patient’s blood. If
there is agglutination, the person is
called Rh positive; if there is NO
agglutination, the person is called Rh
negative.
Unit #5F – Clinical Laboratory
Testing - Basic
Immunohematology
ABO and Rh
Unit #5F – Clinical Laboratory
Testing - Basic
Immunohematology
Try your hand at working in a Blood Bank! Play
the “Blood Typing Game” at this website:
http://nobelprize.org/educational_games/medic
ine/landsteiner/index.html
(Hint: Use the syringe to draw blood from
patients’ arms; then move the syringe over
the blood typing reagents to add it to the
tubes. Once you decide on the correct blood
type, click on the right bag of blood and move
it to the IV pole to start the transfusion.)

Unit #5F – Clinical Laboratory
Testing - Basic
Immunohematology
 Resources
– Basic Clinical Laboratory Techniques,
Estridge and Reynolds, Thomson/Delmar
Learning, Fifth Edition, 2008
– http://nobelprize.org/educational_games/
medicine/landsteiner/index.html
– http://www.pbs.org/wnet/redgold/basics/b
loodcollection.html