RH TYPING AND TESTING FOR WEAK D Flashcards
(89 cards)
1
Q
Second most important blood group when it comes to
immunogenicity and blood transfusion practice
A
Rh BLOOD GROUP SYSTEM
2
Q
Rh BLOOD GROUP SYSTEM
Is the Second most important blood group when it comes to _____
A
immunogenicity and blood transfusion practice
3
Q
Rh BLOOD GROUP SYSTEM
comprises of how many antigens?
A
more than 60 antigens
4
Q
What are the 5 most common rh antigens?
A
D, c, E, C, e
5
Q
means the RBCs have D antigens
A
“Rh-positive”
6
Q
means the RBCs don’t have D antigen
A
“Rh negative
7
Q
absent rh antigens
A
Rh null phenotype-
8
Q
All around the world, the prevalence of Rh- positive type
is high. Around how many percent would have the D antigens on their
RBCs
A
> 90%
9
Q
How many percent
African American (O+)
A
47%
10
Q
How many percent
AFRICAN AMERICAN A-
A
24%
11
Q
How many percent
AFRICAN AMERICAN B-
A
18%
12
Q
How many percent
LATIN AMERICAN O+
A
53%
13
Q
How many percent
LATIN AMERICAN A+
A
29%
14
Q
How many percent
LATIB AMERICAN B+
A
9%
15
Q
How many percent
Caucasian O+
A
37%
16
Q
How many percent
Caucasian A+
A
33%
17
Q
How many percent
Caucasian B+
A
9%
18
Q
How many percent
ASIAN O+
A
39%
19
Q
How many percent
ASIAN A+
A
27%
20
Q
How many percent
ASIAN B+
A
25%
21
Q
is the most common among the
different blood types
A
O positive blood type
22
Q
is considered as universal blood
donor
A
O negative blood type
23
Q
Important in emergency cases and in pregnancy
A
O negative blood type
24
Q
Rh D positive
blood which will not cause Rh hemolytic transfusions
reactions if they’re going to be transfused with Rh
positive blood and also it will not cause any problems
when it comes to transfusion of either A, B, O blood
units.
TRUE OR FALSE?
A
True
25
Transfusion of blood from other blood types will not cause discrepancy of transfusions or in the attending physician..TRUE OR FALSE
FALSE BECAUSE Transfusion of blood from other blood types would
under be the discrepancy of transfusions or
attending physician
26
How many of Filipinos are Rh- positive
99.97%
27
What blood group is important in transfusion practices
RH BLOOD GROUP
28
They are easy to come by
Rh-positive individuals
29
Rh-negative individuals MUST receive Rh-positive blood..TRUE OR FALSE
False because Rh-negative individuals MUST receive Rh-negative blood
30
They are hard to come by, especially in
populations where 90% are Rh-positive
Rh-negative units
31
Introduction of Rh-positive units to Rh-negative patients
can cause the production of what antibody?
alloanti-D
32
It is known to cause severe HDN and AHTRS
Alloanti-D
33
Accurate phenotyping of D and other Rh antigens is very
necessary TRUE OR FALSE
True
34
WHAT ARE THE REAGENTS USED IN RH TYPING?
Saline-based
High protein
Chemically modified
Monoclonal anti-D
35
• Pure IgM reagent
Saline-based
36
First available anti-D
Saline-based
37
Advantage of saline-based
• Low-protein
- Not elicit, agglutination reaction
are maybe even rouleaux
formation which are
advantageous specially the
blood you are going to test has
hyperalbuminemia
- Will also caused viscous blood
samples
- Can be used for testing cells
coated with IgG antibodies
38
Disadvantages of saline based
• Limited availability
• Expensive to produce
• Lengthy incubation time
• Cannot be used for Weak D
typing
39
• Primarily IgG anti-D
HIGH-PROTEIN
40
• Human plasma with high
anti-D
HIGH-PROTEIN
41
• Mixed with potentiators
(dextran, bovine albumin)
HIGH-PROTEIN
42
Advantages of HIGH-PROTEIN
• Reduced incubation time
• Weak D typing and slide
typing may be performed
• Polyspecific
43
DISADVANTAGES OF HIGH PROTEIN
• High rate of false-positives
• Must be performed together
with a control reagent (22%
bovine serum albumin/normal
saline solution
44
Composed of modified,
flexible IgG antibodies
CHEMICALLY
MODIFIED
45
Replaced saline anti- D
reagents
CHEMICALLY
MODIFIED
46
Advantages of CHEMICALLY
MODIFIED
• Slide and tube typing may be
performed
• Doesn't require control tests,
for most of the time
• Fewer false-positives; low
protein
47
Disadvantages of CHEMICALLY
MODIFIED
Requires control if "AB Rhpositive
blood is being teste
48
• Derived from single clones
of antibody- producing
cells
MONOCLONAL ANTI-D
49
• Blend of IgM and IgG
MONOCLONAL ANTI-D
50
Advantages of MONOCLONAL ANTI-D
• Increased specificity
• May be used for most
methods
• Can also be used for weak D
• Not of human source; less risk
for transmitting infections
51
Disadvantage of MONOCLONAL ANTI-D
Narrow specificity
52
In most of our testing procedures we are using what reagent
monoclonal blend of IgM and IgG
53
Reagents for C/c and E/e antigen testing are
manufactured nowadays, helping in ____
antibody screen and
ID.
54
Reagents are NOT USED IN ROUTINE TESTING due to
expensiveness but can be helpful in tertiary
laboratories
Reagents for C/c and E/e antigen testing
55
strict adherence to the
manufacturer's directions must be followed.
Rh antisera
56
PRINCIPLE OF RH TYPING
• DIRECT HEMAGGLUTINATION
Presence of agglutination = Rh antigen testing for is present =
POSITIVE RESULT. If D is tested, RH- POSITIVE
57
do not use latex, instead, use red
blood cells which contain antigens found in RBC
membrane
Indicator particles
58
Antigen found in Indicator particle + particular
antiserum=
agglutination
59
If the test result is Rh negative, immediately
declare/report negative. TRUE OR FALSE??
False!!If the test result is Rh negative, do not immediately
declare negative.
60
What to do if the result is negative?
Perform tube testing or weak D
testing because it provides a proper antigenantibody
ratio.
61
If negative results, Redo testing then check for technical errors encountered
before proceeding with weak D testing.
TRUE OR FALSE?
TRUE
62
FALSE POSITIVE OR NEGATIVE?
Give me the CORRECTION ACTION
- Cell suspension too heavy
False positive
Correction: adjust suspension, retype
63
FALSE POSITIVE OR NEGATIVE?
Give me the CORRECTIVE ACTION
- immunoglobulin-coated cells (in vivo)
False negative
- use saline active typing reagent
64
FALSE POSITIVE OR NEGATIVE?
Give me the CORRECTION ACTION
- Cold agglutinins
False positive
- Wash with warm saline, retype
65
FALSE POSITIVE OR NEGATIVE?
Give me the CORRECTION ACTION
- Saline-suspended cells (slide)
False negative
- Use unwashed cells
66
FALSE POSITIVE OR NEGATIVE?
Give me the CORRECTION ACTION
- Test incubated too long or drying (slide)
False positive
- Follow manufacturers instructions precisely
67
FALSE POSITIVE OR NEGATIVE?
Give me the CORRECTION ACTION
-Failure to follow manufacturer's directions precisely
False negative
- Review directions; repeat test
68
FALSE POSITIVE OR NEGATIVE?
Give me the CORRECTION ACTION
- Rouleaux
False positive
- Use saline-washed cells, retype
69
FALSE POSITIVE OR NEGATIVE?
Give me the CORRECTION ACTION
- Omission of reagent manufacturers directions
False negative
- Always add reagent first and check before adding cells
70
FALSE POSITIVE OR NEGATIVE?
Give me the CORRECTION ACTION
- Fibrin interference
False positive
- Use saline-washed cells, retype
71
FALSE POSITIVE OR NEGATIVE?
Give me the CORRECTION ACTION
- Resuspension too vigorous
False negative
- Resuspend all tube test gently
72
FALSE POSITIVE OR NEGATIVE?
Give me the CORRECTION ACTION
- Contaminating low-incidence antibody in reagent
False positive
- Try another manufacturers reagent or use known serum antibody
73
FALSE POSITIVE OR NEGATIVE?
Give me the CORRECTION ACTION
- Incorrect reagent selected
False negative
- Read vial label carefully, repeat
74
FALSE POSITIVE OR NEGATIVE?
Give me the CORRECTION ACTION
- Polyagglutination
False positive
- See chapter on polyagglutination
75
FALSE POSITIVE OR NEGATIVE?
Give me the CORRECTION ACTION
- Variant antigen
False negative
- Refer sample for further investigation
76
FALSE POSITIVE OR NEGATIVE?
Give me the CORRECTION ACTION
- Bacterial contamination of reagent vial
False positive
- Open new vial of reagent, retype
77
FALSE POSITIVE OR NEGATIVE?
Give me the CORRECTION ACTION
- Reagent detoriation
False negative
- Open new vial
78
FALSE POSITIVE OR NEGATIVE?
Give me the CORRECTION ACTION
- Incorrect reagent selected
False positive
- Repeat test; read vial label carefully
79
FALSE POSITIVE OR NEGATIVE?
Give me the CORRECTION ACTION
- Incorrect reagent selected
False negative
- Repeated test, read vial label carefully
80
FALSE POSITIVE OR NEGATIVE?
Give me the CORRECTION ACTION
- Centrifugation too long
False positive
Repeat the test using shorter centrifugation time
81
FALSE POSITIVE OR NEGATIVE?
Give me the CORRECTION ACTION
- Centrifugation too short
False negative
- Repeat the test using longer centrifugation time
82
FALSE POSITIVE OR NEGATIVE?
Give me the CORRECTION ACTION
- RPM too high
Repeat test using lower RPM
83
FALSE POSITIVE OR NEGATIVE?
Give me the CORRECTION ACTION
- RPM too low
Repeat test using higher RPM
84
Investigate primarily negative results and if you ruled out
false positive and false negative causes, you should
check the background of the person
85
is performed by detecting reagent
antibody-sensitized patient or donor RBCs through
Indirect Coombs' Test (IAT)
Weak D testing
86
What test use to detect weak D
Indirect Coombs' Test (IAT)
87
If the test and record show a negative result, do weak
D phenotyping to declare if person is a really weak d
carrier or a true Rh-, we use what test?
Indirect Coombs' Test (IAT)
88
- Check for RBC sensitize by reagent antibody
- Helps detect in vitro sensitization of RBC
Indirect antiglobulin test
89
The presence of antigens in red blood cells will not cause
agglutination due to the few D antigens present. Upon
adding a reagent antibody (anti- D antiserum having IgG),
there is a binding of antibody to sensitized RBC forming
bridge between two RBCs causing now agglutination (+
result) after centrifugation
Indirect antiglobulin test
