1. Dr. Zahoor Lecture – 5 1 HMIM BLOCK 224

2. Different types of Blood groups blood group system Explain blood typing and how it is used to avoid adverse reactions following blood transfusions. What is erythroblastosis fetalis 2

3. 3 In the year 1900, identification of the ABO blood antigen explained the observed blood type incompatibilities by Karl Landsteiner (Austrian scientist) Today there are 31 different genes known to contribute to the surface features of RBCs determining compatibility between blood types

4.  Major systems  ABO  Rhesus system(Rh)  Minor  MN  P  Kell, Kidd..etc 4

5.  Transfusion of blood  Association of blood group with disease ▪ Duodenal ulcers are more common in group O than in A or B ▪ Tumors of salivary glands, stomach and pancreas are more common in group A than in group O individuals. 5

6. 6 Terms to become familiar with: Antigens( agglutinogen) – a chemical that stimulates cells to produce antibodies Antibodies( agglutinins)– a protein that reacts against a specific antigen Agglutination – clumping of red blood cells in response to a reaction between an antibody and an antigen

7. 7 Based on the presence or absence of two major antigens on red blood cell membranes, we have ABO system. Antigen A Antigen B

8. Blood TypeAntigen on surface of RBC Antibody in plasma AAAnti B BBAnti A ABA and BNeither Anti A nor Anti B ONeither A nor BBoth Anti A and Anti B 8

9. 9 Type B blood Type AB bloodType O blood Red blood cell Anti-B antibody Antigen A Anti-A antibody Anti-B antibody Red blood cell Antigen A Antigen B Red blood cell Anti-A antibody Antigen B Type A blood Plasma BLOOD GROUPS

10. 10 Red blood cell Anti-B antibody (a) (c) (d) (b) Agglutinated red blood cells Anti-A antibody Antigen A Normal blood filmAgglutinated red blood cells BLOOD GROUP TESTING

11. 1. If an agglutinogen (antigen) is present on the RBCs the corresponding agglutinin (anti body) must be absent in the plasma 2. If an agglutinogen (antigen) is absent on the RBCs the corresponding agglutinin (anti body) is present in the plasma 11

12.  Mode of inheritance :- The child receives 1 gene each from each parent. 12 Genes received by child from each parent GenotypeBlood Group (Phenotype) A+AAAA A+OAOA B+BBBB B+OBOB A+BAB O+OOOO

13. 13 The Rh blood group was named after the rhesus monkey The group includes several Rh antigens or factors (Cc, Dd & Ee). D is most important antigen. Rh positive – presence of antigen D antigen on the red blood cell membrane Rh negative – No D antigen on surface of RBC

14.  When person is Rh + or Rh -, there is no antibody in the plasma.  In Rh – persons, Rh agglutinins (antibody) are produced when they are given Rh + blood. 14

15. 15 The importance of the Rh blood group is evident in a fetus that develops the condition erythroblastosis fetalis or hemolytic disease of the newborn Hemolytic disease of newborn occurs when mother is Rh- and fetus is Rh+

16.  At the time of delivery of first baby, some fetal blood will leak into maternal circulation through placenta, therefore mother will develop anti-D after delivery.  During second pregnancy, mother anti-D will cross to fetus and will cause hemolysis. It will cause Hemolytic disease of new born. 16

17.  Clinical Features  Jaundice  Anemia  Edema (Hydrops)  Kernicterus ( Neurological syndrome)  Enlarged Liver & Spleen 17

18.  Treatment  Exchange blood transfusion to baby  Prevention  Rh immune globulin anti D injections to the Rh – negative mother within 72 hours of delivery.  Anti D injection has reduced incidence of Hemolytic disease of new born by 90%. 18

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20. Blood GroupPercentage of Population O +45 % A +41 % B +10 % AB +4 % Rh Positive are about 85%-90% Rh negative are about 10-15% 20

21. Blood GroupPercentage of Population O +49% A +27 % B +20 % AB +4 % Rh Positive are about 93% (90-95%) Rh negative are about 7% (5-10%) 21

22. 22 Blood transfusion Remember reaction takes place between Donor’s RBCs and Recipient’s plasma Donor’s plasma and Recipients RBCs (minor reaction) Blood grouping and cross matching Autologus blood transfusion (blood taken and later on given back to same individual)

23. Blood Type of Recipient Preferred Blood Type of The Donor Permissible Blood Type of The Donor (when necessary) AAO BBO AB A,B, O OONo alternate type 23

24.  BLOOD GROUP O IS UNIVERSAL DONAR.  BLOOD GROUP AB IS UNIVERSAL RECEPIENT. 24

25.  Rh + person can receive Rh + and Rh - blood  Rh - person should receive only Rh - blood Think and reply  What will happen if Rh + blood is given to Rh - person? 25

26.  In mismatched blood transfusion, reaction occur, there maybe ▪ Hemolysis ▪ Jaundice ▪ Renal tubular damage ▪ Death  Circulatory overload – if rapid transfusion  Hemosiderosis – repeated blood transfusion  Transmission of disease ▪ Hepatitis – B ▪ Hepatits C ▪ AIDS 26

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