The Blood Group Systems

Efrida, dr., SpPK., MKes5 Maret 2012

Basic Immunohematology ConceptImmunohematology:Serologic, genetic, biochemical, and molecular study of antigens associated with membrane structures on the cellular constituents of the blood, and immunologic properties & reactions, of all blood components and constituents.

(1900) golongan darah

26 sistem golongan darahPaling penting: ABO RhesusKarl LandsteinerHistory

http://nobelprize.org/medicine/educational/landsteiner/readmore.html

Karl Landsteiner discovered that blood clumping was an immunological reaction which occurs when the receiver of a blood transfusion has antibodies against the donor blood cells. Karl Landsteiner's work made it possible to determine blood types and thus paved the way for blood transfusions to be carried out safely. For this discovery he was awarded the Nobel Prize in Physiology or Medicine in 1930.History of Blood Groups and Blood Transfusions (Cont.)

19-*ErythrocytesStructureBiconcave, anucleateComponentsHemoglobinLipids, ATP, carbonic anhydraseFunctionTransport oxygen from lungs to tissues and carbon dioxide from tissues to lungs

19-*Blood GroupingDetermined by antigens (agglutinogens) on surface of RBCsAntibodies (agglutinins) can bind to RBC antigens, resulting in agglutination (clumping) or hemolysis (rupture) of RBCsGroupsABO and Rh

Erythrocyte Antigens & Antibodies> 700 antigens organized into 29 blood group systems by the International Society of Blood Transfusion (ISBT).

ABO Antigens Also express in many tissues, body fluids, platelet and endothel).Most important blood group system in transfusion and organ transplantation.3 antigens: A, B, H (biosynthetic precursor of A & B antigens).4 phenotypes: group A, B, AB, OA & B: autosomal codominant antigens expressed on group A, B & AB RBC

Null and Weak PhenotypesABO antigens can:Weakened weak A, weak B phenotypesAnomalous:Inherited: cis-ABAcquired:Absence (Null phenotype):Classic Bombay completely absence of all ABH antigens on RBC surfacePara-Bombay shows little/no antigen in RBC but normal in secretion/body fluids.

ABO antigen BiochemistryCarbohydrateABH antigens expressed on RBC glycoproteins & glycosphingolipid (type 2,3,4 chain) RBC origin.Type 1 chain are synthesized by gastrointestinal mucosa secreted into plasma passively adsorbed onto RBC membrane

ABO AntibodiesWeak or absent in newborn 3-6 mo5-10 yo adult levelAdvancing age slight decreaseDetected at room temperature, saline agglutinins with optimal reactivity at 40C.Mostly IgM.IgG (reactive at 370C) can occur after transfusion/pregnancy; higher titer; less readily neutralized by soluble blood group substances.Can fix complement hemolysis in vivo/vitro Can cause: hemolytic transfusion reaction & hemolytic disease of the new born.

Perkembangan antigen-antigen A dan B sel darah merahPerkembangan antigen eritrosit sejak janin s/d remaja.Bayi baru lahir (s/d 3 bulan) : reaksi lebih lemah dibanding dewasa, terutama antibodiJadi pengujian pada BBL cukup eritrosit saja

Less common ABO antibodiesAnti-A1Anti-H

The differences in human blood are due to the presence or absence of certain protein molecules called antigens and antibodies.

The antigens are located on the surface of the RBCs and the antibodies are in the blood plasma.

Individuals have different types and combinations of these molecules.

The blood group you belong to depends on what you have inherited from your parents.

What are the different blood groups?

There are more than 20 genetically determined blood group systems known today

The AB0 and Rhesus (Rh) systems are the most important ones used for blood transfusions.

Not all blood groups are compatible with each other. Mixing incompatible blood groups leads to blood clumping or agglutination, which is dangerous for individuals.

What are the different blood groups?

According to the ABO blood typing system there are four different kinds of blood types: A, B, AB or O (null). ABO blood grouping system

AB0 blood grouping system

The "A and "B" antigens are also produced by some other plants and microorganisms. Thus, individuals who do not recognize one or more of these antigens as "self" will produce antibodies against the plant or microbial antigens.

These antibodies will also react with human antigens of the same kind whether introduced via a blood transfusion or a tissue graft.

Why do individuals produce antibodies to antigens they do not have?

The ABO gene is autosomal (the gene is not on either sex chromosomes)

The ABO gene locusis located on the chromosome 9.

Each person has two copies of genes coding for their ABO blood group (one maternal and one paternal in origin)

Aand B blood groups are dominant over the O blood group

A and B group genes are co-dominant

ABO inheritance and genetics

AUTOSOMAL CHROMOSOMEMustafaSaraone alleles from Mustafa and one from Sara.The alleles for Blood group are in the same place on the chromosome 9. However the genes have a different code giving the different blood groupAB

This meant that ifa person inherited one A group gene and one B group gene their red cells would possess both the A and B blood group antigens.

These alleles were termed A ( which produced the A antigen ), B (which produced the B antigen) and O (which was "non functional"and produced no A or B antigen)

What do co-dominant genes mean?

Possible Blood group Genotypes

ParentAlleleABOABO

The ABO blood groups

The most important in assuring a safe blood transfusion.

The table shows the four ABO phenotypes ("blood groups") present in the human population and the genotypes that give rise to them.

Giving someone blood from the wrong ABO group could be fatal.

The anti-A antibodies in group B attack group A cells and vice versa. Blood group O negative is a different story.

The Rhesus (Rh) System

Golongan Darah RhesusCiri-ciri antigennya mirip dengan sistem ABODapat menyebabkan reaksi ketidak -cocokan pada transfusi atau kehamilan

ABO & Rh(D)*The Rh(D) AntigenRH is the most complex system, with over 45 antigens Discovered in 1940 after work on Rhesus monkeysSubsequently discovered to be unrelated to monkeysRH gene located on short arm of chromosome 1

ABO & Rh(D)*Simple Genetics of Rh(D)86% of caucasians are Rh(D) posThe antithetical antigen d has not been foundThe d gene is recessive:Dd, dD, DD, persons are Rh(D) posOnly dd persons are Rh(D) neg

ABO & Rh(D)

ABO & Rh(D)*Distribution of Rh(D) Types

PopulationRh(D) posRh(D) negCaucasian86%14%African-American95%5%Oriental>99%

ABO & Rh(D)*Significance of Rh(D)80% of Rh(D) neg persons exposed to Rh(D) pos blood will develop anti-DAnti-D can also be stimulated by pregnancy with an Rh(D) positive babySensitisation can be prevented by the use of anti-D immunoglobulin, antenatally and post natallyRh(D) neg females of childbearing potential should never be given Rh(D) positive blood products

ABO & Rh(D)

ABO & Rh(D)*InheritanceABO & RH genes are not linkedABO & Rh(D) type are inherited independentlyFor example:An A Rh(D) pos mother and a B Rh(D) pos father could have an O Rh(D) neg child

ABO & Rh(D)

ABO & Rh(D)*Inheritance of ABO and Rh(D)MotherGroup A AORh(D) pos DdFatherGroup B BORh(D) pos DdGroup A AORh(D) pos DdGroup B BORh(D) pos DdGroup O OORh(D) neg dd

Well, it gets more complicated here, because there's another antigen to be considered - the Rh antigen. Some of us have it, some of us don't. If it is present, the blood is RhD positive, if not it's RhD negative. So, for example, some people in group A will have it, and will therefore be classed as A+ (or A positive). While the ones that don't, are A- (or A negative). And so it goes for groups B, AB and O. The Rhesus (Rh) System

Rh antigens are transmembrane proteins with loops exposed at the surface of red blood cells.

They appear to be used for the transport of carbon dioxide and/or ammonia across the plasma membrane.

They are named for the rhesus monkey in which they were first discovered.

RBCs that are "Rh positive" express the antigen designated D.

85% of the population is RhD positive, the other 15% of the population is running around with RhD negative blood.

The Rhesus (Rh) System (Cont.)

Rh Blood Group and Rh Incompatibility

A person with Rh- blood can develop Rh antibodies in the blood plasma if he or she receives blood from a person with Rh+ blood, whose Rh antigens can trigger the production of Rh antibodies.

A person with Rh+ blood can receive blood from a person with Rh- blood without any problems.

Why is an Rh incompatibility so dangerous when ABO incompatibility is not during pregnancy?

Most anti-A or anti-B antibodies are of the IgM class (large molecules) and these do not cross the placenta.

In fact, an Rh/type O mother carrying an Rh+/type A, B, or AB foetus is resistant to sensitisation to the Rh antigen.

Her anti-A and anti-B antibodies destroy any foetal cells that enter her blood before they can elicit anti-Rh antibodies in her.

This phenomenon has led to an effective preventive measure to avoid Rh sensitisation. Shortly after each birth of an Rh+ baby, the mother is given an injection of anti-Rh antibodies (or Rhogam).

These passively acquired antibodies destroy any foetal cells that got into her circulation before they can elicit an active immune response in her. Rh incompatibility during pregnancy (cont.)

Any questions?

Terima Kasih

Antigen Rh DSejumlah sel dapat bereaksi seperti RhD (+) bila diuji dengan bbrp.macam reagens anti-D, tapi juga bereaksi negatif denagn anti-D yang lain disebut sel-sel D.Setiap donor yang mempunyai D. harus dianggap Rh (+).Pengujian untuk D.D parsial