1	ABO & Rh(D) Blood Groups Anatomy & Physiology Unit 9 – Circulatory System
2	The ABO System Discovered in 1901 by Dr. Karl Landsteiner 4 Main Phenotypes (A, B, AB, O) ABO gene located on long arm of chromosome 9
3	The ABO Antigens Added to Proteins or Lipids in Red Cells Substrate Molecule is H (fucose) A antigen is N-acetyl-galactosamine (GalNAc) B antigen is Galactose (Gal) A and B genes code for transferase enzymes
4	ABO Antibodies A and B substances very common Antibodies produced to “non-self” Produced after first few months of life A & B people have mainly IgM O people have IgG May fade in old age
5	Antigens & Antibodies
6	Inheritance of ABO Groups
7	ABO Typing Cell Group Test Washed Cells With: Monoclonal Anti-A Monoclonal Anti-B Inert control Agglutination is a positive result Reverse Group Test plasma/serum with: Known A₁ cells Known B cells Known O cells ? Known A₂ cells Reactions may be weaker than cell group
8	Distribution of ABO Groups
9	Distribution of the A allele
10	Distribution of the B Allele
11	Distribution of the O Allele
12	Significance of ABO Group ABO mismatched transfusions: Rare May be life threatening Can be caused by technical or clerical error Intravascular haemolysis More severe in group O patients
13	Universal Donor and Recipient Universal Donor Group O Carries no A or B antigens Packed and processed units have little antibody Universal Recipient Group AB Patient has no anti-A or anti-B present Cannot lyse any transfused cells Beware: other antibodies may be present
14	The Rh(D) Antigen RH is the most complex system, with over 45 antigens Discovered in 1940 after work on Rhesus monkeys Subsequently discovered to be unrelated to monkeys RH gene located on short arm of chromosome 1
15	Simple Genetics of Rh(D) 86% of caucasians are Rh(D) pos The antithetical antigen d has not been found The d gene is recessive: Dd, dD, DD, persons are Rh(D) pos Only dd persons are Rh(D) neg
16	Distribution of Rh(D) Types
17	Significance of Rh(D) 80% of Rh(D) neg persons exposed to Rh(D) pos blood will develop anti-D Anti-D can also be stimulated by pregnancy with an Rh(D) positive baby Sensitisation can be prevented by the use of anti-D immunoglobulin, antenatally and post natally Rh(D) neg females of childbearing potential should never be given Rh(D) positive blood products
18	Inheritance ABO & RH genes are not linked ABO & Rh(D) type are inherited independently For example: An A Rh(D) pos mother and a B Rh(D) pos father could have an O Rh(D) neg child
19	Inheritance of ABO and Rh(D)