IMMUNOHEMATOLOGY AND BLOOD BANKING Flashcards
1
Q
extracts made from the seed of plants which have blood group specificity
A
lectins
2
Q
It is used as anti sera for antigen typing red cells
A
lectins
3
Q
blood specificity : Anti - A
lectin :
A
Dolichos biflorus
4
Q
blood specificity : Anti - B
lectin :
A
Bandeiraea simplicifolia
5
Q
blood specificity : Anti - H
lectin :
A
Ulex europaeus
6
Q
blood specificity : Anti - M
lectin :
A
Iberis amara
7
Q
blood specificity : Anti - N
lectin :
A
Vicia graminea
8
Q
blood specificity : Anti - T
lectin :
A
Arachis hypogea (peanut lectin)
9
Q
blood specificity : Anti - Tn (Tn syndrome)
lectin :
A
Salvia sclaera
10
Q
Anti-Tn or Tn syndrome is formerly known as
A
Permanent mixed-field polyagglutinability
11
Q
It is the correlation of ABO antigens on red cells and the reciprocal agglutinating antibodies in the serum of the same individual
A
Landsteiner’s Rule / Landsteiner’s Law
12
Q
won the nobel prize
A
Karl Landsteiner
13
Q
year of the discovery of ABO blood group system
A
1901
14
Q
first anticoagulant used and discovered by who
A
Sodium phosphate ; Braxton Hicks
15
Q
the year 4th blood group (AB) was discovered (decastello & sturli)
A
1902
16
Q
Universal donor of plasma
A
Group AB
- it has no antibodies in plasma
17
Q
Universal donor of packed RBCs
A
Group O
- no antigens
18
Q
Universal recipient of packed RBCs
A
Group AB
19
Q
principle of forward typing
A
detection of ANTIGENS on patient’s RBC with known commercial ANTISERA
20
Q
specimen and reagent used in forward typing
A
specimen: patient’s rbc
reagent: anti-sera
21
Q
forward typing is also known as
A
front
cell
direct
22
Q
formation of ABO antigens
A
5th-6th week of gestation (newborn, in utero)
23
Q
peak production of ABO antigens
A
2-4 years of age
24
Q
color of anti-sera: Anti-A
A
Blue
25
color of anti-sera: **Anti-B**
yellow
26
antisera used for **Rh antigen** that gives (+) or (-) for blood type
Anti-D
27
principle of reverse typing
detection of **ABO antibodies** (isoagglutinins) in serum of patient with **known commercial RBCs**
28
specimen and reagent used in reverse typing
specimen: patient’s serum
reagent: known cells or known commercial RBCs
29
formation of **ABO antibodies**
**3-6 months of age**
- not for newborn; maternal antibody is seen if used for newborn
30
peak production of **ABO antibodies**
5-10 years of age (continuous)
31
2 important classification of ABO antibodies
1. **IgM**- cold reacting; react best at room temp; do not bind to complements
2. **IgG** (immune antibodies - develops upon exposure causing hemolysis) - can cross placenta
32
used to **washed out** antibodies present
saline
33
**unexpected reactions** are obtained in the forward and/or reverse grouping
ABO Discrepancies
34
if there is **antibody missing or extra antibody reacting**, it has problem with patient’s ____
Serum (reverse grouping)
35
if there is **antigen missing or extra antigen reacting**, it has problem with patient’s ____
RBCs (forward grouping)
36
if the patient’s problem is **both Serum and RBCs**, in forward, RCBs must be ____ and _____ if reverse
in forward, RBCs must be **washed** and **saline replacement** if reverse
37
unexpected reactions due to:
1. extra POSITIVE reactions
2. WEAKLY or MISSING reactions
38
All ABO discrepancies must be ____ prior to reporting a patient or donor ABO group
resolved
39
it is usually the discrepant reactions
Weak reactions
40
it is much more common than antigen problems
antibody problems
41
steps in forward typing
step 1: anti-sera
step 2: RBC
42
steps in reverse typing
step 1: serum/plasma
step 2: known cells
43
Common sources of technical errors causing ABO discrepancies
1. **Incorrect or inadequate identification** of blood specimens, test tubes, or slides
2. Cell suspension either **too heavy or too light**
3. **Clerical errors** or incorrect recording of results
4. A **mix-up in samples**
5. **Missed observation of hemolysis**
6. Failure to **add reagents**
7. Failure to **add samples**
8. Failure to **follow manufacturer’s instructions**
9. **Uncalibrated centrifuge**
10. Overcentifugation or undercentrifugation
11. **Contaminated reagents**
12. **Warming** during centrifugation
44
**Group I Discrepancies**
problem:
- unexpected reaction with ____
- weakly reacting or missing ____
resolution:
- incubate patient’s _____________ @ RT for 15-30 minutes
- if still no reaction, incubate _____ @ ____ for 15-30 minutes
problem:
- REVERSE GROUPING
- ANTIBODIES
resolution:
- PATIENT’S SERUM with REAGENT A1 & B CELLS
- SERUM-CELL MIXTURE @ 4degC
45
examples of group I discrepancies
1. **Newborn** (ABO antibody production not detectable until 3-5 months of age)
2. **Elderly** (production of ABO antibody is **depressed**
3. Leukemia (CLL) or Lymphoma (ML) or Patients using **immunosuppressive drugs** demonstrating *hypogammaglobulinemia*
46
**Group II Discrepancies**
problem:
- unexpected reaction with ____
- weakly reacting or missing ____
resolution:
- incubate patient’s _____________ @ RT for 30 minutes
- if still no reaction, incubate _____ @ ____ for 15-30 minutes
problem:
- FORWARD GROUPING
- ANTIGENS
resolution:
- patient’s RBC with reagent ANTI-SERA
- TEST MIXTURE @ 4degC
47
examples of group II discrepancies
1. **subgroups of A & B**
2. Leukemia - *weakened A or B antigens*
3. Hodgkin’s disease - mimic depression of antigens
4. Acquired B phenomenon - *weak reactions* with *anti-B antisera* (blood type A)
48
**Group III Discrepancies**
problem:
- unexpected reaction with ____
- protein or plasma abnormalities —>
resolution:
- forward grouping: wash patient’s RBCs several times with ____
- reverse grouping: ____ technique [serum=saline]
problem:
- FORWARD & REVERSE GROUPING
- ROULEAUX formation or PSEUDOAGGLUTINATION (false agglutination)
resolution:
- SALINE; wash RBC 2-3x; wash cord cells 6-8x (due to wharton’s jelly)
- SALINE REPLACEMENT (serum is removed and replaced by an equal volume of saline)
49
example of group III discrepancies
1. Elevated levels of **globulin** - MM, Waldenstrom’s macroglobulinemia, other plasma cell dyscrasias, and certain moderately advance cases of Hodgkin’s lymphomas
2. Elevated levels of **fibrinogen**
3. Plasma expanders (*Dextran & Polyvinylpyrrolidone*)
4. Wharton’s Jelly (cord samples)
50
ABO antigens are made up of _____ & _______
**glycolipids** and **glycoproteins**
51
precursor of A & B antigens (sugar)
Oligosaccharides
52
group in ABO discrepancies wherein discrepancies between forward and reverse grouping are due to ______
group IV; MISCELLANEOUS PROBLEMS
53
**Group IV Discrepancies**
problem:
- **potent cold autoantibodies** —> yield +coomb’s/antiglobulin test
resolution:
- incubate patient’s _____________ @ 37degC for short period of time —> washed saline 3x @37degC —> retype
if not successful:
- forward: patient’s rbc + ______
- reverse: reagent rbcs and serum can be _______ for 10-15 minutes, mixed, tested, and read @ 37degC
- convert the test to _____ if necessary
resolution:
- patient’s RBC
if not successful:
- 0.01 M dithiothreitol (DTT)
- incubate/warmed @ 37degC
- AHG Phase
54
**Group IV Discrepancies**
problem:
- **Weakly reactive Anti-A or Anti-B**
resolution:
- may not react at 37degC
if reverse typing is still negative:
- ________ (patient’s cells with patient’s serum) - **remove cold autoantibody from serum**
- the ______ can then be used to repeat the serum typing @ RT
- Cold autoabsorption
- absorbed serum
55
**Group IV Discrepancies**
problem:
- _______ - this happens to those blood types that have subgroups
resolution:
- _______ - produce small amount of **Anti-H**
- A2B & A2 - produce _____
- serum grouping can be repeated using at least 3 examples of _________(known reagent cells) and _________ control (patient’s serum mixed with patient’s rbcs)
- test patient’s rbc with ________ (lectin specific for A1 antigen)
problem:
- Unexpected ABO isoagglutinins
resolution:
- A1B & A1
- Anti-A1
- A1, A2, B cells ; O cells
- Autologous
- Dolichos biflorus
56
once the unexpected alloantibodies are identified, this should be used in the reverse grouping
reagent A1 and B cells that is negative for corresponding antigen
57
these are ABO water soluble substances found in **saliva and other body fluids**
ABH SECRETOR
58
Principle of detection in ABH secretor
based on **agglutination inhibition**/**neutralization**
59
secretor that produce A, B, H in secretions
**SeSe** and **Sese**
60
it is a non secretors; no A, B, H soluble substances found in secretions
**sese**
61
Glycoprotein
Type 1 precursor chain
B 1-3 linkage of D-galactose and N-acetylglucosamine
62
soluble substances in blood type A
A & H soluble substances
63
soluble substances in blood type B
B & H soluble substances
64
soluble substances in blood type AB
A, B, & H soluble substances
65
soluble substances in blood type O
H soluble substances
66
in agglutination inhibition/neutralization test, no agglutination means
positive
67
it has a lot of H antigens
O cells
68
it detects anti-IgG or anti-complement
AHG Testing (Coomb’s test)
69
reagent of AHG testing
**Polyspecific AHG** and **Monospecific AHG**
70
contain antibody to human IgG & C3d to component of human complement
Polyspecific AHG
71
in Polyspecific AHG, this complement may also be present
Anti-C3b
72
this type of reagent in coomb’s test **can facilitate agglutination** when RBCs have been **sensitized with IgG or C3d or Both**
Polyspecific AHG
73
commercially prepared polyspecific AHG contains antibody activity against ______
IgA and IgM HEAVY CHAINS
74
polyspecific mixture contains antibody activity to _____
KAPPA & LAMBDA LIGHT CHAINS
75
**contains anti-IgG and anti-C3d** (may contain other anticomplement and other anti-immunoglobulin antibodies)
Rabbit Polyclonal
76
contains a blend of rabbit polyclonal **antihuman IgG** and **Anti-C3d** is a murine monoclonal IgM antibody
Rabbit/Murine Monoclonal Blend
77
contain only **one** antibody specificity that is either anti-IgG or C3d/C3b
Monospecific AHG
78
License monospecific reagents commonly used are:
Anti-IgG
Anti-C3d
Anti-C3b
79
type of monospecific reagent that contains anti-IgG with **no anticomplement activity**
Anti-IgG (Rabbit Polyclonal)
80
**Murine monoclonal IgM antibody** secreted by a *hybridoma cell line*
Anti-IgG (Gammaclone AHG)
81
main component of Anti-complement (anti-C3d)
murine monoclonal antibody to C3d
82
this will **cause the agglutination of RBCs** coated with human **C3d** and/or **C3b complement components**
Anti-C3d
83
Oligosaccharide precursor chain Type 1
B 1,4 —> D-galactose, 4- N-acetylglucosamine (H gene)
84
Oligosaccharide precursor chain Type 2
B 1,3 —> (Se gene)
85
In agglutination inhibition test, saliva is mixed with antisera. To inactivate the enzymes, it must be heated at __________
56degC for 10 minutes
86
these are diluted to prevent postzone
saliva and antisera
87
It detects **In Vivo sensitization of RBCs** with IgG or complement components
Direct Antiglobulin Test (DAT)
88
Detected by **ONE-STAGE** procedure
Direct Antiglobulin Test (DAT)
89
Clinical application: **HDFN**
In vivo sensitization: _______
Maternal antibody coating fetal RBCs
90
Clinical application: **HTR**
In vivo sensitization: ________
Recipient antibody coating donor RBCs
91
Clinical application: **AIHA**
In vivo sensitization: _______
Autoantibody coating individual's RBCs
92
Detects **In VITRO sensitization of RBCs** with IgG or complement components
Indirect Antiglobulin Test (IAT)
93
Detected by **TWO-STAGE** procedure
Indirect Antiglobulin Test (IAT)
94
Focus of antibody detection
determine the **irregular** or **unexpected** antibodies
95
Primary important; produced in **response to RBC stimulation** through transfusion, transplantation or pregnancy
(ex. mother ---> fetus)
Immune alloantibodies
96
Form as a result of **exposure to environmental sources**, such as *pollen, fungus,* and *bacteria*, which have structure similar to some RBC antigens
Naturally occurring alloantibodies
97
Antibodies produced in **one individual and then transmitted to another individual** via **plasma-containing blood components** or derivatives such as **intravenous immunoglobulin** (IVIG)
via **transfusion mechanism** from one individual to you
Passively acquired antibodies
98
**Antibodies directed against antigens** expressed on one's own RBCs and generally react with all RBCs tested
*own's antibodies produced to target own red cell (antigen)*
Autoantibodies
99
Phase of antibody detection used to detect antibodies reacting at **room temperature**
Immediate Spin (IS) Phase
100
Phase of antibody detection wherein IgG antibodies (if present in patient's serum) will sensitize any reagent RBC that possess the target antigen
37 deg C Incubation Phase
101
Phase of antibody detection that detects **IgG** or **complement-sensitized RBCs**; AHG reagent (Coomb's serum)
AHG Phase
102
In phases of antibody detection, this may be added **prior** to incubation at 37degC to **increase the degree** of sensitization
Enhancement reagent
103
AHG Phase Interpretation:
If the RBCs are coated with IgG antibodies, the **ANTI-IgG ANTIBODY in the AHG reagent** will create a bridge between sensitized reagent RBCs
Agglutination
104
AHG Phase Interpretation:
If there are no antibodies directed against any of the antigens present on the reagent RBCs, the **RBCs will not be sensitized**
No agglutination
105
RBC reagents source:
Group O individuals (Group O cells)
- **Anti-A & Anti-B** will not interfere with the detection to other blood group system
106
Antibody detection *screen cells*
R1R1 & R2R2
or
R1R1, R2R2 & rr
107
There should be **ONE CELL** that is **POSITIVE** for each of the following antigens:
**D, C, c, E, e, K, k, Fya, Fyb, Jka, Jkb, Lea, Leb, P1, M, N, S, & s**
*Blood donor antibody screening* is **acceptable** while *patient antibody screening* **cannot be used**
Pooled Reagent/Reagent Set
108
Phase of antibody detection that reacts best at **room temperature or lower**; capable of *causing agglutination of saline-suspended RBCs*
Anti-N, Anti-I, Anti-P1
IgM Class
(Immediate spin / 37 degC or lower)
109
Phases of antibody detection that reacts best at **AHG Phase** (warmer temperature @ 37 degC)
Anti-Rh, Anti-Kell, Anti-Duffy, Anti-S, Anti-s
IgG Class
(AHG Phase)
110
Phases of antibody detection that **reacts at 37 degC**
Anti-Lewis, Anti-M
IgM or IgG
(37 deg C Incubation Phase)
111
It is patient's RBC tested against the patient's serum (in the same manner as the antibody screen)
Autologous control
112
**(+) Antibody screen**
**(-) Autologous control**
there is a presence of
ALLOANTIBODY
113
**(+) Autologous control**
the _________ needs to be evaluated
Transfusion history (of the patient)
114
If the patient has **not been transfused within the last 3 months**, Autologous control is **POSITIVE**, there is presence of __________ or ____________
AUTOANTIBODIES or ANTIBODIES TO MEDICATION
115
A **Positive** autologous control and **exhibits mixed-field appearance** is caused by ________ coating the circulating donor of RBCs
ALLOANTIBODIES
116
Screen cells (+); reacts at **SAME PHASE & STRENGTH**
Single Antibody Specificity
117
Screen cells (+); reacts at **DIFFERENT PHASES & STRENGTH** (IS, 37degC, AHG)
Multiple Antibodies
118
Screen cells (+)
Autocontrol/DAT (+)
Autoantibodies
119
In the presence of complement *anti-Lea, anti-Leb, anti-pp1pk, & anti-vel* causes _________ hemolysis
In vitro
120
Complement associated with **Mixed-field agglutination**
Anti-Sda & Anti-Lua/b
121
- The appearance under the microscope appears **"stack of coin"**
- Not a significant finding in antibody screening tests
- **Does not interfere with AHG Phase**
- Non-specific aggregation of RBCs (altered *albumin-to-globulin ratio* -- MM or those who received *high molecular weight plasma expanders* [dextran])
Presence of **Rouleaux**
122
This test is used in the following situations:
1. Detection of *incomplete* (non-agglutinating) *antibodies* to **potential donor RBCs** (compatibility testing) or to *screening cells* (antibody screen) in **serum**
2. Determination of **RBC phenotype using known antisera** (e.g., Weak D, any other antigen testing that requires this test)
3. *Titration of incomplete antibodies*
Indirect Antiglobulin Test
123
Clinical application: **Antibody Detection**
Tests: a.) **Compatibility testing**
b.) **Antibody Screening**
In vitro sensitization: __________
a.) **Recipient** antibody reacting with **donor cells**
b.) **Antibody** reacting with **screening cells**
124
Clinical application: **Antibody Identification**
Tests: **Antibody Panel**
In vitro sensitization: __________
**Antibody** reacting with **panel cells**
125
Clinical application: **Antibody Titration**
Tests: **Rh Antibody Titer**
In vitro sensitization: __________
**Antibody & Selected Rh cells**
126
Clinical application: **RBC Phenotype**
Tests: **RBC antigen dectection** (ex. Weak D, K, Fy)
In vitro sensitization: __________
**Specific antisera + RBCs** to detect antigen
127
Clinically significant alloantibodies:
- Causes **low survival of RBCs** possessing the target antigen
- **Typically IgG**
- React @: **37degC** and/or **AHG Phase of IAT**
128
Tasks and purposes of IAT task
1. Incubate RBCs with antisera
2. Perform a minimum of three saline washes
3. Add antigloblulin reagent
4. Centrifuge
5. Examine for agglutination --> *(+) agglutination; (-) no agglutination*
6. Grade agglutination reactions
7. Add antibody-coated RBCs to negative reactions --> countercheck/control only
129
**REMEMBER THIS**
If **(+) screen cells (SC)** --> ALLOANTIBODIES
If **(+) AHG** --> WARM REACTING / 37degC (IgG)
If **(+) IS (immediate spin)** --> COLD REACTING (IgM)
130
Guidelines for Interpretation
*Autocontrol*
a.) Negative - ______
b.) Positive - _______
a.) **ALLOANTIBODY**
b.) **AUTOANTIBODY**
131
Guidelines for Interpretation
*Phases*
a.) IS - _____
b.) 37degC - ________
c.) AHG - _______
a.) **COLD ANTIBODY** (IgM)
b.) **COLD ANTIBODY** (some have higher thermal range) or **WARM ANTIBODY**
c.) **WARM ANTIBODY** (IgG) clinically significant
132
Guidelines for Interpretation
*Reaction Strength*
a.) 1 consistent strength - _______
b.) different strengths - _______
a.) **ONE** antibody
b.) **MULTIPLE** antibodies or **DOSAGE**
133
Common Blood Group System with Antibodies that Exhibit Dosage
1. Rh (except D)
2. Kidd
3. Duffy
4. MNSs
5. Lutheran
134
Antibody Identification
**Antibody Panel** --> usually induces at least _____ panel cells
Panel cells --> ________
(+) - presence of antigen
(0) - absence of antigen
10 panel cells
panel cells --> Group O RBCs
135
Autocontrol should also be run with **ALL** panels
Autocontrol = ________ + __________
Patient's RBC + Patient's Serum
136
Perform Immediate Spin (IS)
--> grade agglutination
--> inspect for hemolysis
137
Perform 37 degC Phase (LISS)
--> add 2 drops of LISS, mixed & incubate for 10-15 minutes
--> mix/centrifuge
--> check for agglutination
138
Perform IAT (or AHG)
--> wash cells 3x with saline
--> add 2 drops of AHG
--> mix/centrifuge
--> check for agglutination
139
COLD REACTING ANTIBODIES
1. **P, I, Lewis, MN**
2. Naturally Occurring
3. Generally **IgM**
4. Can't cross placenta
5. Reacts best @ **RT**
6. Not significant in HTR
140
WARM REACTING ANTIBODIES
1. **Kell, Kidd, Duffy, Ss**
2. Requires Exposure
3. Generally **IgG**
4. *Can cross the placenta*
5. Reacts best at **37degC**
6. Significant in transfusion reactions
141
Enzyme Classification
**Enhance** by ENZYME
ABO
Rh
Kidd
Lewis
I/I
P1
142
Enzyme Classification
**Destroyed/Inactivated** by ENZYME
MNSs
Duffy
Xga
143
Enzyme Classification
**Not affected** by ENZYME
Kell
144
The **most important** of all blood groups in both **transfusion** and **transplant medicine**
ABO System
145
Transfusion of an *incompatible ABO type* may result in:
Immediate **lysis** of donor RBCs
146
A foundation on which all other pretransfusion testing is based
ABO incompatibility
147
Most frequent cause of death in fiscal year (FY) 2015
Transfusion-related acute lung injury (TRALI)
148
First individual to perform forward and reverse grouping
Karl Landsteiner
149
Most frequently performed test in the blood bank
ABO Grouping
150
Interpretation of Blood Group
Anti-A : **0**
Anti-B : **0**
Blood Group **O**
151
Interpretation of Blood Group
Anti-A : **4+**
Anti-B : **0**
Blood Group **A**
152
Interpretation of Blood Group
Anti-A : **0**
Anti-B : **4+**
Blood Group **B**
153
Interpretation of Blood Group
Anti-A : **4+**
Anti-B : **4+**
Blood Group **AB**
154
Interpretation of Blood Group
A1 Cells : **4+**
B Cells : **4+**
Blood Group **O**
155
Interpretation of Blood Group
A1 Cells : **0**
B Cells : **3+**
Blood Group **A**
156
Interpretation of Blood Group
A1 Cells : **3+**
B Cells : **0**
Blood Group **B**
157
Interpretation of Blood Group
A1 Cells : **0**
B Cells : **0**
Blood Group **AB**
158
Characteristics of Routine Reagents Used for ABO Testing
**Forward Grouping**
Anti-A Reagent
1. Monoclonal antibody
2. Highly specific
3. IgM
4. *Clear blue-colored reagent*
5. Expected 3+ to 4+ reaction
6. Usually use 1-2 drops
159
Characteristics of Routine Reagents Used for ABO Testing
**Forward Grouping**
Anti-B Reagent
1. Monoclonal antibody
2. Highly specific
3. IgM
4. *Clear yellow-colored reagent* (contains an **acriflavine dye**)
5. Expected 3+ to 4+ reaction
6. Usually use 1-2 drops
160
Characteristics of Routine Reagents Used for ABO Testing
**Reverse Grouping**
Reagent A1 and B Cells
1. Human source
2. 4%-5% RBC suspension
3. Expected 2+ to 4+ reaction
4. Usually use 1 drop
161
Anti-A : **0**
Anti-B : **0**
Anti-AB: **0**
A1 Cells : **4+**
B Cells : **4+**
Blood group **O**
162
Anti-A : **4+**
Anti-B : **0**
Anti-AB: **4+**
A1 Cells : **0**
B Cells : **2+**
Blood group **A**
163
Anti-A : **0**
Anti-B : **4+**
Anti-AB: **4+**
A1 Cells : **3+**
B Cells : **0**
Blood group **B**
164
Anti-A : **3+**
Anti-B : **3+**
Anti-AB: **3+**
A1 Cells : **0**
B Cells : **0**
Blood group **AB**
165
If wrong ABO group is transfused, the ABO antibodies will cause ___________ resulting to *patient death*
rapid intravascular **hemolysis**
166
**Routinely used reagent for performing ABO confirmation of group O donor**; more economical to use
Anti-A,B reagent
167
Year the inheritance of the ABO blood group was first described
1924
168
Considered an **amorph**, as *no detectable antigen* is produced
O gene
169
Three (3) separate **loci**
ABO, Hh, Se
170
Has the same basic precursor material from which A, B, and H antigens all originate
**Paragloboside** or **glycan**
171
Precursor structure on which A and B antigens are made
H antigen
172
Glucosyltransferases and Immunodominant Sugars Responsible for H, A, and B Antigen Specificities
**H gene** elicits the production of an enzyme called **a-2-L-fucosyltransferase** that transfers the sugar to ______
**L-fucose** to an *oligosaccharide chain*, terminal galactose of *type 2 chains*
173
Sugars occupying the terminal positions of precursor chain and conferring blood group specificity are called
Immunodominant sugars
174
Term used to refer to the phenotype that lacks normal expression of the ABH antigens
Bombay
175
Glucosyltransferases and Immunodominant Sugars Responsible for H, A, and B Antigen Specificities
**A gene** elicits the production of an enzyme called **a-3-N-acetylgalactosaminyltranferase** that transfers the sugar to ______
**N-acetyl-D-galactosamine** (GalNAc); type 2
176
Glucosyltransferases and Immunodominant Sugars Responsible for H, A, and B Antigen Specificities
**B gene** elicits the production of an enzyme called **a-3-D-galactosyltransferase** that transfers the sugar to ______
**D-galactose** (Gal); type 2
177
Oligosaccharide chain, **type 1 and 3** are primarily associated with
body secretions
178
Oligosaccharide chain, **type 2 and 4** are primarily associated with
red blood cell membrane
179
Type of oligosaccharide chain that are **more abundant** and differ only in the linkage position of *galactose* (Gal) to *N-acetylglucosamine* (GlcNAc)
Type 1 and 2 chains
180
Comparison of ABH Antigens on RBCs with A, B, and H Soluble Substances
**ABH Antigens on RBCs**
1. RBC antigens can be *glycolipids, glycoproteins or glycosphingolipids*
2. RBC antigens are *synthesized only on **type 2** precursor chains*
3. Type 2 chain refers to a beta 1-->4 linkage
4. The enzyme produced by the H (FUT 1) gene (a-2-L-fucosyltransferase) acts primarily on *type 2* chains, which are prevalent on the RBC membrane
181
Comparison of ABH Antigens on RBCs with A, B, and H Soluble Substances
**A, B, H Soluble Substances**
1. Secreted substances are **glycoproteins**
2. Secreted substances are *primarily synthesized on **type 1** precursor chains*
3. Type 1 chain refers to a beta 1-->3 linkage
4. The enzyme produced by the Se (FUT 2) gene (a-2-L-fucosyltransferase) preferentially acts on *type 1* precursor chains in secretory tissues
182
Anti-A + Saliva + A cells : 4+
Anti-B + Saliva + B cells : 4+
Anti-H + Saliva + O cells : 0
Interpretation:
Type **O** Secretor
- H soluble substances
183
Anti-A + Saliva + A cells : 0
Anti-B + Saliva + B cells : 4+
Anti-H + Saliva + O cells : 0
Interpretation:
Type **A** Secretor
- A & H soluble subsances
184
Anti-A + Saliva + A cells : 4+
Anti-B + Saliva + B cells : 0
Anti-H + Saliva + O cells : 0
Interpretation:
Type **B** Secretor
- B & H soluble secretor
185
Anti-A + Saliva + A cells : 0
Anti-B + Saliva + B cells : 0
Anti-H + Saliva + O cells : 0
Interpretation:
Type **AB** Secretor
- A, B, H Soluble substances
186
Fluid in which A, B, and H substances can be detected in secretors
1. Saliva
2. Tears
3. Urine
4. Digestive juices
5. Bile
6. Milk
7. Amniotic fluid
8. Pathological fluids: *pleural, peritoneal, pericardial, ovarian cyst*
