abobloodgroupsystem-170121130000.pptx

blood grping

1. AB O BLOO D G R OUP SYSTEM & genetics

2. ABO BLOOD GROUP SYSTEM T he ABO blood group system is the most important blood group system in human blood transfusion. Found on platelets, epithelium and cells other than erythrocytes, AB antigens can also cause an adverse immune response to organ transplantation. The associated anti-A and anti-B antibodies are usually IgM antibodies, which are produced in the first years of life by sensitization to environmental substances, such as food, bacteria, and viruses.

3. ABO blood group antigens present on red blood cells

4. ● HISTORY KARL LANDSTEINER discovered the ABO Blood Group System in 1901. He and five co-workers began mixing each others red blood cells and serum together and accidentally performed the first forward and reverse ABO groupings.

5. LANDSTEINER’S LAW If an agglutinogen is present on red blood cell membrane, the corresponding agglutinin must be absent in the plasma. If an agglutinogen is absent on red blood cell membrane, then the corresponding agglutinin must be present in the plasma.

6. I M P OR T A NC E O F A B O There are two principles- 1) Almost all normal healthy individuals above 3-6 months of age have “ naturally occurring Abs ” to the ABO Ags that they lack. These Abs termed naturally occurring because they were thought to arise without antigenic stimulation .

7. 2) These “ naturally occurring ” Abs are mostly IgM class . That means that, they are antibodies capable of agglutinating saline/ low protein suspended red cell without enhancement and may activate complement cascade. * *

8. B LO OD G R O U P A N T I GE N S ON CELL A N TIB O D I E S I N PLASMA A A Anti-B B B Anti-A AB A and B none O None Ant i - A a n d B

9. ABO TYPING ABO typing involves both antigen typing and antibody detection. The antigen typing is referred to as the forward typing and the antibody detection is the reverse typing The forward typing determines antigens on patient's or donor's cells Cells are tested with the antisera reagents anti- A, anti-B, (and in the case of donor cells anti-A,B) Reagents are either made from hyper immunized human sources, or monoclonal antibodies. One advantages of the monoclonal antibodies are the antibody strength.

10. FORWARD TYPING REACTIONS OF CELLS TESTED WITH RED CELL ABO GROUP A N T I - A A N T I - B O + A + B + + AB

11. The reverse typing determines antibodies in patient’s or donor’s cells. Serum tested with reagent A 1 cells and B cells Reverse grouping is also known as backtyping or serum confirmation REVERSE TYPING REACTIONS OF SERUM TESTED AGAINST REVERSE ABO GROUP O A B A1 Cells B Cells + + + + 0 0 AB

12. ABO GENE & GENETICS The ABO blood type is controlled by a single gene (the ABO gene) with three types of alleles i, IA, and IB. The I designation stands for isoagglutinogen , another term for antigen. ❑ ❑ ❑ ❑ The gene encodes a glycosyltransferase . The gene is located on the long arm of the ninth chromosome (9q34) I A a l l e l e g i v e s t yp e A , I B g i ve s t y p e B , i g i ve s t y p e O. I A and I B are dominant over i. O group : Only ii A g r ou p : I A I A o r I A i AB group : I A I B B group : I B I B or I B i I A I B p e o p l e h a v e b o t h p h en o t y p e s , b e c a u s e A a n d B e x p res s a special dominance relationship: co dominance , which means that t y p e A a n d B p a ren t s c a n h a v e a n A B c h i ld.

13. A and B are co dominan t giving the AB phe noty p . e

14. BLOOD GROUP INHERITANCE

15. ABO ANITGEN GENETICS The presence or absence of the ABH antigens on the red blood cell membrane is controlled by the H gene • The presence or absence of the ABH antigens in secretions is indirectly controlled by the Se gene • H gene – H and h alleles (h is an amorph) • Se gene – Se and se alleles (se is an amorph)

16. BOMBAY GROUP T h e h / h b l oo d g r o u p , a l so k n o w n a s O h [ or the Bombay blood group, is a rare blood type. This blood [phenotype] was first discovered in Bombay, now known as Mumbai, in India, by Dr. Y.M.Bhende in 1952. The Hh blood group contains one antigen, the H antigen, which is found on virtually all RBCs and is the building block for the production of the antigens within the ABO blood group.

17. H antigen deficiency is known as the "Bombay phenotype" (h/h, also known as Oh) and is found in 1 of 10,000 individuals in India and 1 in a million people in Europe. There is no ill effect with being H deficient , but if a blood transfusion is ever needed, people with this blood type can receive blood only from other donors who are also H deficient . (A transfusion of "normal" group O blood can trigger a severe transfusion reaction.) The peculiarity is that they do not express the H antigen . As a result they cannot form A antigens or B antigens on their red blood cells. Thus they can donate blood to anyone.

18. RH BLOOD GROUP SYSTEM o T h e R h b l oo d g r o u p s y s t e m ( i nc l uding the Rh factor ) is one of thirty-five current human blood group systems. It is the second most important blood group system, after ABO. Rh derives from rhesus and the terms r Ł e s u s b l o o d g r o u p s y s t e m , r Ł e s u s f a c t o r , r Ł e s u s p o s i t i v e a n d r Ł e s u s ne g a tiv e are also used. Rh is a blood group system with many antigens, one of which is D.

19. RH (D) ANTIGEN Unlike the ABO blood group system, individuals who lack the D antigen do not naturally make it. Production of antibody to D requires exposure to the antigen. The D antigen is very immunogenic, i.e, individuals exposed to it will very likely make an antibody to it. For this reason all individuals are typed for D, if negative must receive Rh (D) negative blood.

20. RH (D) ANTIGEN {CONTINUED} The most important patient population to consider is females of child-bearing age. If immunized to Rh (D) antigen the antibody can cross the placenta and destroy Rh (D) positive fetal cells resulting in death. This is why Rh negative women are given Rhogam after birth of Rh positive baby.

21. TH A NK Y O U .