Blood grouping in Humans.................

1. Blood grouping in Humans JV Vishnu saai dev XI th class

2. History of the blood grouping and significance. Karl Landsteiner (1868-1943) discovered isoagglutinin in human blood in 1900, Leading to recognition of human blood groups and success of blood transfusion. He proposed Landsteiner law

3. What is Landsteiner law? This law states that if a particular aggulutinogen is present on the red cell membrane of an individual, the corresponding agglutinin must be absent in his plasma. Conversely, if the agglutinogen is absent in the red cells, the corresponding agglutinin must be present in the plasma.

4. Now let’s see what is agglutinin and agglutinogen agglutinin It is present on the Cell membrane of RBC Agglutinogen This Photo by Unknown Author is licensed under CC BY-SA It is present in the plasma. .

5. Let’s revisit the law 1 st part of the law states, If a particular agglutinogen is present on the RBC membrane For example let’s say the blood group of a person is A according to ABO blood grouping system(which we will study later) The RBC has A agglutinogen. It shouldn’t have it’s corresponding agglutinin which is in this case Anti-A antibodies.

6. Now let’s understand 2 nd part of the law If a certain agglutinogen is absent in RBC, for understanding let’s take those Surface antigens A are lacking on the RBC membrane which is true in the B blood group. It says the the corresponding agglutinogen must be present in the plasma, in our case it is Anti-A antibodies must be present. No surface A antigen Present.

7. Let’s learn about important ABO blood grouping It has two agglutinogens. A and B agglutinogen. Specific parts of A and B agglutinogens are mounted on H antigen. H antigen doesn’t have any agglutinin. Agglutinogen=antigen

8. Blood groups in ABO blood grouping system A,B,AB,O

9. Analysing the agglutinogens and agglutinin in different ABO blood group IN MISMATCHED BLOOD TRANSFUSION

10. COMPATIBILITY OF BLOOD GROUPS FOR TRANSFUSION(Major cross matching) RECEIPIENT A GROUP(ANTI-B AGGLUTININS) B GROUP(ANTI-A AGGLUTININS) AB GROUP(NO AGGLUTININS) O GROUP(ANTI A & B AGGLUTININS) DONOR A,O B,O A,B,AB,O(ALL) ONLY O

11. Points worth remembering AB is universal receipient . O is universal donor

12. Genetics of ABO blood grouping A & B are dominant alleles whereas O is recessive allele. Recessive alleles need homozygous(O+O) genotype for expression Dominant alleles need only one allele to express.

13. Understanding Rh Blood Grouping 13 C,D,E,c,d,e Out of these D is most immunologically active. What antigens are present? Inheritance of Rh antigen. What are the blood groups in this system? It is Rh positive(Dd & DD) and Rh negative(dd). Fun fact: Rh means rhesus monkey because this blood group was 1 st found in it. D is the dominant allele d is a recessive allele.

14. Clinical Significance of Rh Blood Grouping 14 Rh blood grouping is pivotal in identifying compatible blood for transfusion. Adequate blood matching based on Rh type is crucial in medical practice . That means that the Rh - ve should be only transfused Rh- ve blood. Transfusion Relevance Point to be noted Medical Applications In pregnancy, Rh compatibility influences maternal-fetal health . Rh- ve mother with Rh+ve fetus causes a disease called Erythroblastosis fetalis. Because Anti-D antibodies of the mother affect the Rh+ve RBC of the fetus. The anti-D antibodies are not initially present in the plasma of the Rh- ve person. The anti-D antibodies are developed when the antigens( Rh+ve ) are exposed to the Rh- ve blood. That’s why the 1st pregnancy is unaffected in Rh+ve pregnancy in Rh- ve mother.

15. Other blood groups system at a glance MNS Antigen system Lutheran system Kell system Duffy system Kidd system