Blood Type Distribution and Genetics Quiz

The clumping of red blood cells caused by antibodies binding to antigens on the cell surface.

A type of antibody that is better at causing agglutination due to its pentameric structure.

Decreases the electrostatic repulsion between red blood cells, enhancing the detection of cold antibodies and autoantibodies.

Excludes water, increasing concentration of antibodies and making it easier to detect warm antibodies and autoantibodies.

The initial stage in agglutination where antibodies coat red blood cells.

A blood group system primarily based on the presence of a specific antigen (A, B, or neither) on red blood cells.

Individuals with this blood type lack both A and B antigens on their red blood cells, making them universal donors.

Individuals with this blood type have A antigens on their red blood cells.

Individuals with this blood type have B antigens on their red blood cells.

Individuals with this blood type have both A and B antigens on their red blood cells.

A blood test that detects antibodies or complement proteins attached to red blood cells in the blood.

This type of Coombs test evaluates red blood cells outside of the body to see if they are coated with antibodies or complement, which might indicate an immune reaction.

This type of Coombs test evaluates red blood cells directly from the patient's blood to see if they are coated with antibodies or complement, which might indicate an immune reaction happening in the body.

These are red blood cells that have been coated with antibodies. They are used as a control in Coombs tests to ensure the test is working properly.

The strength of an antibody's reaction with red blood cells depends on the number of copies of the antigen on the red blood cell. This is called dosage.

A protein, glycoprotein, or glycolipid found on the surface of red blood cells (RBCs) that can be identified by a specific antibody.

A group of blood group antigens that are genetically linked. There are 30 total blood group systems recognized by the International Society of Blood Transfusion (ISBT).

An antibody that causes a reaction strong enough to lead to a transfusion reaction (HTR) or hemolytic disease of the fetus and newborn (HDFN).

An antibody that reacts best at body temperature (37°C), commonly found in IgG.

An antibody that reacts best below body temperature (37°C), often found in IgM.

Certain enzymes can break down glycoproteins on RBC surfaces, enhancing or masking specific antigens. This can help identify antibodies by either strengthening or weakening the reaction with RBCs.

Neutralization occurs when specific substances inhibit the activity of red cell antibodies, preventing them from reacting with test red cells. This can be achieved by mixing antibodies with substances like saliva or plant extracts.

Lectins are plant extracts that bind to specific carbohydrate structures found on RBCs. These lectins can be helpful in identifying rare blood group antigens, and are especially useful in the recognition of polyagglutination.

Polyagglutination is a phenomenon where red blood cells agglutinate (clump together) with most or all human sera (blood plasma). This is often caused by the presence of unusual antigens on the RBC surface. Lectins are helpful tools for identifying the cause of polyagglutination.

The FUT enzyme adds fucose to the terminal galactose, forming the H antigen, which is necessary for A and B antigens to exist on red blood cells.

H antigen comes in two types: type 1 and type 2. Type 1 is found in secretions, while type 2 is found in red blood cells and secretions. Both are necessary for the production of A and B antigens.

The ABO blood group system is determined by three genes: A, B, and O. The A and B genes code for transferase enzymes that add different sugars to the H antigen, creating the A and B antigens, respectively. The O gene is nonfunctional, meaning it doesn't produce any enzymes.

ABO antigens appear on fetal red blood cells as early as week 6 of gestation and reach adult levels by age 4. They are found on various tissues, not just red blood cells.

Clinically significant antibodies, called anti-A, anti-B, and anti-A,B, develop naturally in the blood. The type and reactivity of these antibodies depend on the individual's ABO blood group. For example, individuals with blood group A have anti-B antibodies.

Direct lysis of a red blood cell due to antibody coating. It's less common than agglutination but requires complement fixation. IgM antibodies are more effective than IgG in inducing hemolysis.

A test method that uses serum and red blood cells, mixed and spun for a short time, to detect antibodies that react quickly. These antibodies are usually IgM.

A test phase where serum and red blood cells are incubated at 37°C with or without potentiators to enhance antibody reactions. This phase allows for detection of antibodies that react more slowly, often IgG.

A component added to the 37°C phase that helps to increase the sensitivity of antibody detection. Examples include LISS, PEG, and no potentiation.

A test phase where unbound globulins are removed by washing the red blood cells, and then anti-human globulin (AHG) is added to detect any antibody-coated red blood cells.

A test method that uses microtubes filled with gel particles and anti-IgG to detect antibodies bound to red blood cells. The red blood cells migrate through the gel based on whether they are bound to IgG or not.

A test method that detects antibodies by their ability to bind to red blood cell antigens attached to the bottom of microwells. It uses indicator red blood cells coated with anti-IgG to visualize antibody binding.

A type of solid-phase red cell adherence testing that uses specialized devices to automate several steps of the test, including incubation, washing, and interpretation.

ABO discrepancies occur when the cell and serum grouping results do not match, indicating a mismatch in either the antigens or antibodies present, or potential technical errors.

Missing antigens may be due to subgroups, recent transfusion or transplantation, or conditions like leukemia.

Unexpected antigens are typically caused by transfusion or transplantation, the rare acquired B phenotype, or recent marrow or stem cell transplants.

Missing antibodies can occur with immunodeficiency diseases, in neonates, the elderly, or immunocompromised individuals.

Unexpected antibodies could be due to cold antibodies, anti-A1 antibodies, false-positive reactions from rouleaux formation or plasma expanders, or even a recent transfusion.

A rare phenomenon where individuals with group A blood express a weak B antigen due to bacterial enzymes altering their A antigen.

A rare, inherited condition where individuals with group B blood express a weak A antigen. It's the opposite of acquired B.

A rare blood type characterized by the complete absence of H, A, and B antigens. This is caused by the absence of the H and Se genes.

A variation of the Bombay phenotype where individuals lack the H antigen but may express free A or B antigens. They still need H-negative blood for transfusions.

A serious transfusion reaction that can occur after receiving blood from an incompatible donor. This causes the recipient's immune system to attack the donor's red blood cells.

A condition that can occur in babies when the mother's antibodies attack the baby's red blood cells. This is usually mild but can be serious.

A blood group system based on the presence or absence of Lewis antigens on red blood cells. These antigens are determined by the Le gene.

A type of Lewis antigen that is made by the Le gene. It is a precursor to the Le$^b$ antigen but cannot be modified to make Le$^b$ antigen.

In blood group systems, some antigens are not directly attached to the red blood cell surface, but rather adsorb onto the surface through weaker interactions.

Present in individuals who express the 'Se' gene, they add fucose to the 'Le' antigen, resulting in the formation of the 'Leb' antigen.

Individuals with this genotype lack the 'Se' gene product, making them unable to convert 'Lea' to 'Leb'. Consequently, only 'Lea' antigen is present.

Individuals with this genotype have both the 'Le' and 'Se' genes, leading to the presence of predominantly 'Leb' antigen, with a smaller amount of 'Lea' that might not be detectable.

The Lewis system's antigens can be found on the same chain as ABO antigens, but their expression is not influenced by the presence of ABO antigens. This means they don't directly compete with each other.

These are naturally occurring antibodies found primarily in individuals lacking both Lea and Leb antigens.

Lewis antigens decrease in pregnant individuals due to potential dilution by increased plasma volume or removal by plasma lipoproteins.

Although they have the gene for Lea, Le(a-b+) individuals often don't produce anti-Lea antibodies. This is because they have Lea antigen present on their RBCs, albeit in small amounts.