1. Blood Transfusion

2. Learning Objectives  To describe and explain the ABO blood grouping system  To describe and explain the Rhesus blood grouping system  To investigate a blood grouping problem practically

3.  There are over 30 different types of system to identify and characterise blood but the 2 main systems are the ABO system and the Rh factor system  Others include the Kell system, M & N systems, Lea & Leb system as well as many more

4. ABO System

5.  Discovered by Karl Landsteiner in 1900 as a result of seeing patients react when blood was given to them  Inherited trait from parents. Receive 1 allele from each parent from chromosome 9 (9q34)  Blood group is determined by the antigens present on red blood cells

6.  As well as antigens, antibodies are involved in the reaction. These antibodies can cause clumping or agglutination when blood of the wrong type is transfused into someone  Antibodies are known as Anti-A and Anti-B.  For a successful transfusion a recipient must not be able to produce Anti-A or Anti-B antibodies in response to a donors red blood cells  If the recipient does produce Antibodies the recipient may experience an AHTR (acute Heamolytic transfusion reaction) which could be life threatening

7.  People with type O blood are considered to be a universal donor as they do not possess A or B antigens so no reaction will take place  People with type AB blood are considered to be universal recipients as they do not have any Anti-A or Anti-B antibodies present in their blood which could cause a reaction

8. Rhesus

9.  In addition to the ABO system, the Rhesus system also types blood further  The system was developed by Fisher and Race. It is the most commonly used system although others have been developed  It relates to the presence of the D antigen on the surface of the RBC. Rh+ indicates the presence of the D antigen on their surface  Transfusing with the incorrect RH factor may result in agglutination of RBC in the recipient

10. Blood Typing

11.  When blood is donated it is screened for infection and then typed. The most common blood types are A, B, AB & O. We can see the antigens present on the RBC’s from the table below

12.  In addition, blood is also typed for its Rh factor. Therefore blood is typed as A-, A+, B-, B+, AB-, AB+, O- & O+. Once the blood has been typed it can be donated according to the table below

13. Practical

14.  You are going to investigate the ABO blood grouping system using simulated blood  Follow the instructions on the worksheet given to you. You must use a new toothpick for each experiment you do.  Construct a table of your results and determine which blood types each of the patients has  Whilst there is no blood in this test, treat it as if you were handling blood

15. Results

16. Agglutination with Anti-A Agglutination with Anti-B Blood group John+-A Baby Matthew -+B David++AB Mary--O ABO Blood type

17. SampleAgglutination with Anti-Rh Rh Factor is Mary-Rh- David+Rh+ Baby Matthew+Rh+ John+Rh+ Rhesus Factor Results

18. PatientBlood type JohnA+ Baby MatthewB+ DavidAB+ MaryO- Which blood types could these patients receive with risk of rejections (AHTR)?