Rh Blood Group System Overview

The D antigen is crucial in blood transfusions, more important than A and B. Individuals without the D antigen (D negative) can develop anti-D antibodies if exposed to the D antigen, making transfusions more complex.

The D antigen is more likely to trigger an immune response than many of the other antigens.

An outdated blood group system that incorrectly suggested 3 pairs of genes determine Rh antigens.

The two genes that actually determine the Rh antigens, which are closely linked.

Inherited gene complexes that are passed from parents to offspring to determine the Rh blood type.

The theory suggested multiple gene pair interactions controlling Rh antigens, which is untrue. Modern understanding shows it's a combination of two closely linked genes.

Understanding various blood group systems, including Fisher-Race and newer systems, is crucial in the medical field, and it allows for patient-specific transfusion requirements.

Routine testing helps ensure D-negative blood is transfused to D-negative patients to avoid complications & immune reaction.

Different forms of a gene that control the presence of antigens on red blood cells.

Each allele leads to the production of specific antibodies on red blood cells.

Both alleles in a gene pair are expressed in the phenotype.

A system for representing Rh genotypes using a shorthand notation for alleles and corresponding antigens.

Another system for representing Rh genotypes using a different system of notation regarding alleles (genes).

The combination of alleles inherited from both parents for the Rh system.

The observable traits (antigens) on the red blood cells determined by the genotype.

A system for classifying Rh antigens based on serological reactions.

Describes the presence or absence of specific Rh antigens on red blood cells, using a symbol followed by a colon and a list of antigen numbers.

Phenotype is the observed antigen presence on the red blood cell, while genotype is the underlying genetic code determining it. Genotype is harder to determine than phenotype.

International Society of Blood Transfusion system for blood group nomenclature that standardizes blood group names to a 6 digit code.

Protein or carbohydrate markers on the surface of red blood cells, used to determine blood type.

A method used to record red blood cell phenotypes and identifying antigen status.

The D antigen is the most important Rh antigen because it can cause severe immune reactions during blood transfusions.

A technique that analyzes the DNA to determine blood group genes and their specific antigens.

Using known frequencies of blood types in a population to predict the most likely genotype given a phenotype.

A variant of the RhD antigen that may not be fully expressed, making it less immunogenic in some cases but potentially causing severe reactions in others.

Rh antigens formed from the combined expression of two Rh genes on the same chromosome, creating new epitopes.

Specific Rh antigen present only where the c and e antigens are in a cis configuration on the same chromosome.

A rare condition where individuals inherit a portion or all of the Rh genes imperfectly or do not express them altogether.

Standard practice to prevent potential harm from anti-D alloantibodies by transfusing patients with blood lacking the D antigen.

The combination of Rh genes inherited from both parents.

An antibody produced in response to the presence of the D antigen from a different individual.

Rh genes located on the same chromosome.

A technique used to reduce the reactivity of anti-I antibodies, usually seen in blood typing tests. It involves warming the blood sample before testing to lower the likelihood of other antibodies being involved.

Antigens (Lea and Leb) found on red blood cells, but not intrinsically part of the cell. They're secreted into, and then absorbed from, the plasma before appearing on RBCs.

A technique used to distinguish between anti-I and other auto-antibodies by removing the anti-I from serum using cold-incubated red cells.

The expression of Lewis antigens (Lea and Leb) on red blood cells develops gradually in infants and children, typically fully mature after a few years.

Lewis antigen strength can change during pregnancy, potentially leading to the temporary production of Lewis antibodies in a person who is normally Lewis-negative.

Lewis blood group antigens aren't reliable for determining paternity in infants due to their variable expression and relatively late development.

The presence or absence of Lewis antigens is controlled by a single gene called the "Le" gene.

Lewis antigens are not directly produced on red blood cells by their own synthesis, but are absorbed into the cells from the plasma.

Lewis antigens are present in secretions and can be neutralized in the lab by adding Lewis substance, eliminating reactivity with antibodies.

Lewis antibodies rarely cause in-vivo hemolysis in transfusions because transfused RBCs acquire the recipient's Lewis phenotype rapidly, and the donor plasma's Lewis substance neutralizes the antibodies.

The P blood group was initially discovered in 1927 when rabbits were immunized with human RBCs, and then renamed to P1.

P1 individuals possess the P1 antigen, while P2 individuals lack it. Other P phenotypes exist, but are rare.

Kell antibodies, most commonly anti-K, are clinically significant IgG antibodies causing hemolytic transfusion reactions (HTRs) and severe hemolytic disease of the fetus and newborn (HDFN).

The K antigen is highly immunogenic, leading to a frequent production of anti-K antibodies, which are responsible for numerous HTRs.

Transfused blood cells acquire the recipient's Lewis phenotype within days and this is vital for transfusion compatibility.

Lewis antibodies present in the patient are neutralized by Lewis substance in the donor plasma, avoiding in-vivo hemolysis.