What are the main functions of a blood collection unit?
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Recruits, screens and draws blood donors, and performs screening tests for blood units.
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What are the main functions of a blood collection unit?
Recruits, screens and draws blood donors, and performs screening tests for blood units.
What is the primary role of a blood bank in a hospital?
Performs compatibility testing and prepares blood components.
What does Landsteiner's Law state about antigens on RBCs?
Antigen on the RBC determines the blood group.
What ABH substances are found in the saliva of secretors with blood group O?
H
What are the responsibilities of a blood center?
Screens donors, draws donors, performs testing on donor blood, and delivers appropriate components to hospital blood banks.
What does a result of 0 in Anti-A, Anti-B, and Anti-A,B indicate in cell grouping?
It indicates the absence of A, B, and AB antigens on the red blood cells.
How many A antigen sites are present in Type A blood?
810,000 to 1,170,000 A antigen sites.
According to Landsteiner's Law, is the corresponding antibody to an antigen found in the individual's serum?
No, the corresponding antibody is never found in the individual’s serum.
What ABH substances are found in the saliva of secretors with blood group A?
A, H
What does a result of 0 in A1 cells, B cells, and O cells indicate in serum grouping?
It indicates the absence of antibodies against A, B, and O cells in the serum.
How many B antigen sites are present in Type B blood?
610,000 to 830,000 B antigen sites.
What type of antibody is always present in an individual's serum according to Landsteiner's Law?
The opposite antibody is always present in the individual’s serum.
What ABH substances are found in the saliva of secretors with blood group B?
B, H
What reactions indicate that both Anti-A and Anti-B are present in the serum grouping?
Both Anti-A and Anti-B show 4+ reactions.
What can be inferred from an autocontrol result of 0?
It indicates that there are no autoantibodies present in the serum reacting with the individual's own red blood cells.
How many A antigen sites are present in Type AB blood?
600,000 A antigen sites.
Which blood group has the greatest amount of H antigens?
Group O
What is the reaction with Anti-A and Anti-B for blood group O in ABO forward grouping?
Reaction with Anti-A: -, Reaction with Anti-B: -
What are the other names for Reverse Grouping?
Serum Typing, Reverse Typing, and Indirect Typing.
What ABH substances are found in the saliva of secretors with blood group AB?
A, B, H
What is the most common group of ABO discrepancies?
Group I: Weakly-reacting or missing antibodies.
What is the reaction for Anti-A,B in the given example?
3+
How many B antigen sites are present in Type AB blood?
720,000 B antigen sites.
Which blood group has the least amount of H antigens?
Group A1B
What is the reaction with Anti-A and Anti-B for blood group A in ABO forward grouping?
Reaction with Anti-A: +, Reaction with Anti-B: -
What does the H gene (FUT1) code for?
The precursor substance on which the A and B gene products act.
What does Reverse Grouping detect?
The presence of antibodies.
What is the first step in Group III resolution?
Verification of patient’s clerical information.
Which group of ABO discrepancies involves weakly-reacting or missing antigens?
Group II: Weakly-reacting or missing antigens.
What is the reaction for A1 cells in the given example?
1+
Arrange the blood groups in order of decreasing amount of H antigens.
O > A2 > B > A2B > A1 > A1B
What diseases are associated with elevated levels of globulin in Group III?
Multiple myeloma, Waldenstrom’s macroglobulinemia, Plasma cell dyscrasias, and advanced Hodgkin's lymphoma.
What is the reaction with Anti-A and Anti-B for blood group B in ABO forward grouping?
Reaction with Anti-A: -, Reaction with Anti-B: +
What is an autoantibody?
An autoantibody is an antibody that is directed against an individual's own proteins.
Which chromosomes are the H (FUT1) and Se (FUT2) loci closely linked on?
Chromosome 19.
What purpose does Reverse Grouping serve in blood typing?
It serves as a confirmatory procedure for cell typing.
What is the Cis-AB phenotype?
Inheritance of three ABO genes instead of two (A, B, and O).
What should be reviewed in the Group III resolution process?
Patient’s profile and medical history.
What causes Group III ABO discrepancies?
Protein or plasma abnormalities leading to rouleaux formation.
What is the reaction for B cells in the given example?
0
Which protein's elevated levels are mentioned in Group III?
Fibrinogen.
How does the amount of H antigens in blood group A2 compare to blood group A1?
A2 has more H antigens than A1.
What is the reaction with Anti-A and Anti-B for blood group AB in ABO forward grouping?
Reaction with Anti-A: +, Reaction with Anti-B: +
How did World War II affect blood preservation research?
It stimulated blood preservation research because of the increased demand for blood products.
What is an alloantibody?
An alloantibody is an antibody that is directed against antigens from another individual of the same species.
What do blood group antigens refer to?
Genetically encoded antigen systems on erythrocytes, leukocytes, thrombocytes, and plasma.
What is used in Reverse Grouping?
Known red cell suspension.
What is the function of the products of the A and B genes?
They are enzymes that act as specific transferases.
How are A and B genes inherited in the Cis-AB phenotype?
A and B genes are inherited in cis position.
What is Group IV in the context of ABO discrepancies?
Miscellaneous.
In Group III resolution, how many times should red cells be washed?
2-3 times.
What studies should be performed for polyagglutination?
Lectin studies.
What is the reaction for O cells in the given example?
0
What are some examples of plasma expanders listed in Group III?
Dextran and polyvinylpyrrolidone.
What are other names for Forward Typing?
Cell Typing, Direct Typing, Red Cell Typing
What is an ABO discrepancy?
ABO discrepancies are recognized when the reactions obtained in the forward type do not match the reactions obtained in the reverse type.
Which blood group has more H antigens: A1B or B?
B has more H antigens than A1B.
Who was appointed director of the 1st American Red Cross blood bank at Presbyterian Hospital in 1941?
Dr. Charles Drew
What is a cause of discrepancies in Group IV related to non-ABO alloantibodies?
Reagent cells do not only contain A and B antigens.
What must be considered for resolving the acquired B phenomenon?
Acidified antiserum and patient’s own anti-B will not agglutinate acquired B cells, monoclonal anti-B ES4 clone should not be used, reacetylation of acquired B cells using acetic anhydride, and secretor studies may be performed.
What are naturally occurring antibodies?
Naturally occurring antibodies are those whose stimulus is unknown.
What is the usual position of A and B genes in inheritance?
A and B genes are usually in trans position.
What concentration of red cell suspension is used in Reverse Grouping?
2-5% red cell suspension.
Where can blood group antigens be found?
On erythrocytes, leukocytes, thrombocytes, and plasma.
How many times should cord blood cells be washed in Group III resolution?
6-8 times.
How should you handle cold reacting antibodies during blood typing?
Incubate at 37°C, wash 3 times with NSS heated to 37°C, then repeat blood typing. If there is still a problem, use DTT or 2-ME.
What does an autocontrol reaction of 0 indicate in the given example?
It indicates no autoantibodies are present.
What is Wharton’s Jelly?
A gelatinous substance within the umbilical cord, containing fibers and cells.
What must be determined when an ABO discrepancy is observed?
One must determine if the problem is associated with the forward type, reverse type, or both.
What is the purpose of Forward Typing?
To detect antigens on the RBC surface
Why might a patient have a reaction to Anti-B antiserum in Group IV discrepancies?
The patient has an antibody to acriflavine, which is present in Anti-B antiserum.
What is polyagglutination classified under in ABO blood group discrepancies?
Group IV (caused by miscellaneous problems).
What does a 3+ reaction with Anti-A and Anti-A,B indicate in cell grouping?
The presence of A antigens on the red blood cells.
Why should monoclonal anti-B ES4 clone not be used in acquired B phenomenon?
It is not effective for resolving acquired B cells.
What significant development in blood preservation occurred in 1943?
Acid-Citrate-Dextrose was introduced by Loutit and Mollison.
What genetic phenomenon does the Cis-AB phenotype represent a problem in?
Crossing-over.
What are immune antibodies and how are they formed?
Immune antibodies are formed as a result of antigen exposure.
What is the first step in resolving a Group II ABO discrepancy?
Verification of patient’s clerical information.
What are glycosyltransferases?
Enzymes that facilitate the transfer of carbohydrate (sugar) molecules onto carbohydrate precursor molecules.
What are low-incidence antigens also known as?
Private or Family Antigens.
What does a negative (Neg) agglutination reaction indicate?
No aggregates; dark, turbid, homogenous supernatant.
Which type of antibodies are naturally occurring in the ABO blood group system?
IgM.
What technique is performed to differentiate rouleaux from true agglutination?
Saline replacement technique.
What is the reaction of blood group O in ABO reverse grouping with both A cells and B cells?
Blood group O shows a reaction of + with both A cells and B cells.
What temperature is used for elution in the case of warm reacting antibodies?
45 degrees Celsius.
What is polyagglutination?
RBC agglutinates with ABO compatible sera due to altered membrane component.
What does a false positive reaction mean in the context of ABO discrepancies?
A false positive means the reaction should have been negative but agglutination occurred.
What type of reagents are used in Forward Typing?
Commercial antisera of known specificity
What does a 0 reaction with Anti-B indicate in cell grouping?
The absence of B antigens on the red blood cells.
What is the purpose of reacetylation of acquired B cells using acetic anhydride?
To resolve the acquired B phenomenon.
What happens when anti-acriflavin and acriflavin form a complex?
They spontaneously agglutinate.
What kind of antibodies cause agglutination regardless of the antisera specificity?
Cold reactive antibodies.
Why is it important to review the patient's profile and medical history during Group II resolution?
To identify any factors that might affect the ABO typing results.
What significant event related to blood transfusion occurred in 1492?
Blood was taken from 3 young men and given to Pope Innocent VIII; all four died.
What notable event in the blood preservation field happened in July 1947?
The Journal of Clinical Investigation devoted to blood preservation was published.
What role do glycosyltransferases play in biochemistry?
They facilitate the transfer of carbohydrate molecules onto precursor molecules.
What are high-incidence antigens also known as?
Public Antigens.
What is observed in a Weak (+/-) agglutination reaction?
A few isolated aggregates; mostly free-floating cells; supernatant appears red, dark, or turbid.
What is significant about the B[A] phenotype?
Presence of trace amounts of A antigen on B red blood cells.
At what temperature do the naturally occurring antibodies in the ABO blood group system react?
At room temperature.
What is chimerism?
The presence of two cell populations.
What is the reaction of blood group A in ABO reverse grouping with A cells and B cells?
Blood group A shows a reaction of - with A cells and + with B cells.
What should be performed for antibodies other than Anti-A and Anti-B?
Antibody Screening and Identification, then repeat typing.
What is the grading description for a 4+ reaction in gel technology?
Agglutinated cells form a cell layer at the top of the gel media.
What is the term for genes that do not produce any detectable trait?
Amorph
What causes RBCs to agglutinate in polyagglutination?
Altered membrane component.
What organisms are associated with TK-polyagglutination?
Bacteroides fragilis, Serratia marcesens, Candida albicans
What does a false negative reaction mean in the context of ABO discrepancies?
A false negative means the reactions should have been positive but no agglutination occurred.
What does a 0 reaction with A1 cells, B cells, and O cells in serum grouping suggest?
The absence of anti-A and anti-B antibodies in the serum.
Who discovered the A, B, and O blood groups in the ABO Blood Group System?
Karl Landsteiner.
Which group of patients is most frequently associated with chimerism?
Newborns, geriatrics, and patients who have undergone bone marrow transplantation.
What is a characteristic of RBCs with the cis 'AB Phenotype'?
They may cause discrepancies in blood typing.
What can be performed as part of resolving acquired B phenomenon to check the secretion of B substances?
Secretor studies.
Which dye is used in Anti-A antiserum?
Bromphenol blue (trypan blue)
What are warm autoantibodies?
Antibodies that react at body temperature causing autoagglutination.
How can the reaction be enhanced during the resolution of a Group II ABO discrepancy?
By incubating the reagent red cells with the patient’s serum at room temperature for about 15-30 minutes.
Who recommended sodium phosphate as an anticoagulant for blood preservation in 1869?
Braxton Hicks.
What is an immunodominant sugar?
It is the sugar molecule that completes the antigenic determinant when combined with the precursor substance.
What is Tn polyagglutination?
An acquired A phenomenon.
What advancement in blood preservation was made in 1957?
Citrate-Phosphate-Dextrose was introduced by Gibson.
What does ABO discrepancy mean?
ABO discrepancy refers to a mismatch or unexpected results between forward and reverse blood typing tests.
How are trace amounts of A antigen synthesized on B red blood cells in the B[A] phenotype?
By the B-gene enzyme.
What is the nature of the naturally occurring antibodies in the ABO blood group system?
Cold-reacting antibodies.
What does a 1+ agglutination reaction look like?
A few small aggregates just visible macroscopically; many free erythrocytes; turbid reddish supernatant.
What does it mean when both cell populations in chimerism are recognized as self?
It means true chimerism.
What is the reaction of blood group B in ABO reverse grouping with A cells and B cells?
Blood group B shows a reaction of + with A cells and - with B cells.
Where are agglutinated cells concentrated in a 3+ reaction grading?
Concentrated near the top of the microtube.
What enzyme is responsible for adding L-fucose to the precursor substance to form antigen H?
L-fucosyltransferase
What does genotype refer to?
Genotype refers to the genes.
What is acquired polyagglutination associated with?
Microbial-associated factors.
Which enzyme is linked to TK-polyagglutination?
B-endogalactosidase
What is the key to resolving ABO discrepancies?
The key is to recognize which type of problem is occurring so that appropriate testing can be performed.
What is the significance of a 0 autocontrol?
It indicates no autoantibodies are present in the patient's serum.
What are some examples of ABO subgroups?
Subgroups within the ABO blood group system.
What must be done if there is an excess of BGSS present?
Patient red cells must be washed.
What are common causes of ABO discrepancies?
Common causes include technical errors, weak or missing antibodies, and the presence of subgroups or atypical antibodies.
Who discovered the AB blood group in the ABO Blood Group System?
Sturli and Von Decastello.
What does CAD stand for in the context of inherited polyagglutination?
Cazal Autosomal Dominance.
What is a further method to enhance the resolution reaction in Group II ABO discrepancies?
By incubating the samples and reagents at 4 degrees Celsius for 15 minutes.
What did Karl Landsteiner discover in 1901?
Karl Landsteiner discovered the ABO blood groups.
Which dye is used in Anti-B antiserum?
Acriflavine dye
How does an immunodominant sugar function in antigen formation?
By combining with the precursor substance to complete the antigenic determinant.
What are some examples of unexpected ABO isoagglutinins?
Anti-A1 in A2 and A2B individuals, Anti-H in A1 and A1B individuals, Anti-A or Anti-B in weak subgroups.
In what forms are ABO blood group antigens found?
Partly as glycolipids, but primarily as glycoproteins.
What are the causes of true chimerism?
Twins and mosaicism due to dispermy.
Describe the characteristics of a 2+ agglutination reaction.
Medium-sized aggregates; some free erythrocytes; clear supernatant.
What is the reaction of blood group AB in ABO reverse grouping with A cells and B cells?
Blood group AB shows a reaction of - with both A cells and B cells.
How are agglutinated cells observed in a 2+ reaction grading?
Agglutinated cells disperse into the gel media and are observed throughout the length of the microtube.
Which sugar is added by L-fucosyltransferase to form antigen H?
L-fucose
What does phenotype refer to?
Phenotype refers to demonstrable antigen.
Name a phenomenon associated with microbial-related polyagglutination.
Hubner-Thomas-Friedenrich- Phenomenon.
Which organisms are associated with the Acquired B phenomenon?
E. coli O86, P. vulgaris OS19, Clostridium tertium
Which patients are associated with hypogammaglobulinemia due to leukemia?
Patients with leukemia.
How can technical errors lead to ABO discrepancies?
Technical errors such as improper labeling, contamination, or incorrect reagent use can result in discrepancies during blood grouping tests.
What is the most important blood group system?
The ABO Blood Group System.
What action can be taken if forward typing results are inconsistent?
Forward typing may be repeated using antisera with a different lot number.
Who carried out a vein-to-vein transfusion using multiple syringes and special cannula in 1901?
Edward Lindemann.
Why must autocontrol and O cells be checked during the resolution of Group II ABO discrepancies?
To rule out the presence of autoantibodies.
Which dyes are used in AHG antiserum?
Ariavit tartrazine + Patent Blue V
What antigen is associated with CAD in inherited polyagglutination?
SID antigen.
In which individuals do you find Anti-A1?
In A2 and A2B individuals.
What does it mean when only the original cell population is recognized as self in chimerism?
It means false chimerism.
What is observed in a 3+ agglutination reaction?
Several large aggregates; some free erythrocytes; clear supernatant.
What happens to agglutinated cells in a 1+ reaction grading?
Agglutinated cells disperse throughout the gel media and may concentrate toward the bottom of the tube.
What sugar does N-acetylgalactosaminyltransferase add to antigen H to form antigen A?
N-acetyl-D-galactosamine
What is a homozygous genotype?
A homozygous genotype consists of identical alleles.
What is T-polyagglutination?
A type of microbial-associated acquired polyagglutination involving T-cryptic antigen.
Which enzyme is linked to the Acquired B phenomenon?
D-acetylase
What are forward and reverse blood typing tests?
Forward typing identifies antigens on red blood cells, while reverse typing detects antibodies in the plasma.
What condition is frequently found in patients with lymphoma and those on immunosuppressive drugs?
Hypogammaglobulinemia.
What makes the ABO Blood Group System the most immunogenic yet simplest?
Its strong immune response and straightforward classification into A, B, AB, and O.
What apparatus did Unger design in 1901?
Unger designed his syringe-valve apparatus.
What does HEMPAS stand for?
Hereditary Erythroblastic Multinuclearity with Positive Acidified Serum Test.
What does a 4+ reaction in Cell Grouping indicates?
A strong positive reaction
In which individuals do you find Anti-H?
In A1 and A1B individuals.
What are some causes of false chimerism?
Blood transfusions, transplanted bone marrow, exchange transfusion, and feto-maternal bleeding.
What does a negative reaction indicate in gel technology?
All cells pass through the gel media and form a cell button at the bottom of the microtube.
What does a positive reaction with Anti-A indicate in cell grouping?
The presence of A antigens on the red blood cells.
What are the four main blood groups in the ABO blood group system?
A, B, AB, and O.
Describe the characteristics of a 4+ agglutination reaction.
All erythrocytes are combined into one solid aggregate; clear supernatant.
Which enzyme is responsible for adding D-galactose to antigen H to form antigen B?
D-galactosyltransferase
What is the characteristic reaction of the B3 subgroup with Anti-B?
Mixed field and rapid agglutination with Anti-B.
What type of enzyme and which organisms are associated with T-polyagglutination?
Organisms with neuraminidase such as V. cholerae, Influenza virus, Pneumococci, E. coli, and Clostridium.
What is a heterozygous genotype?
A heterozygous genotype consists of different alleles.
What is Th-polyagglutination?
Th-polyagglutination is a type of polyagglutination.
In what other form can ABO blood group antigens occur in secretions?
As glycoproteins.
Why might weak or missing antibodies cause ABO discrepancies?
Weak or missing antibodies can lead to less visible agglutination reactions, making it difficult to interpret test results accurately.
What is a common characteristic of patients with congenital agammaglobulinemia?
Hypogammaglobulinemia.
What is the most common cause of Hemolytic Disease of the Fetus and Newborn (HDFN)?
The ABO Blood Group System.
Who reported sodium citrate as an anticoagulant for blood transfusions in 1914?
Hustin.
What antigen is related to HEMPAS?
I antigen on CDA type II normoblast.
What does a 4+ reaction in Serum Grouping indicate?
A strong positive reaction
Which antibodies might be found in weak subgroups of ABO blood groups?
Anti-A or Anti-B.
Which blood type is known as the universal donor?
Type O negative.
What is the first step in the most frequent resolution for Group I ABO discrepancies?
Review patient's profile.
How does the Anti-B reagent react in this example?
It shows a 2+ reaction indicating the presence of B antigens.
What are the two sugars added to antigen H in AB individuals?
N-acetyl-D-galactosamine and D-galactose
Describe the appearance of cells in a mixed-field reaction grading.
Agglutinated cells form a layer at the top of the gel media, while unagglutinated cells pass to the bottom of the microtube.
What distinguishes the Bx subgroup in terms of agglutination?
Weak agglutination with Anti-B and Anti-A, B without mixed field agglutination.
Who are the three scientists associated with the nomenclature of the ABO blood group system?
Landsteiner, Jansky, and Moss.
