1. BLOOD PHYSIOLOGY Practical 1
BLOOD GROUPS
Phase II Medicine- Blood Module - May 2008

2. Phase II Medicine- Blood Module - May 2008
Objectives
Describe the clinical significance of determination of blood groups.
Name the blood groups of ABO & Rh system.
Describe the principle of determination of blood groups.
Determine blood groups by using anti-A and anti-B antisera.
Mention the common indications of blood transfusion.
List the common hazards of transfusion.
Name the diseases transmitted by blood transfusion.
Describe the concept of universal donor and universal recipient.
Describe the cause of erythroblastosis fetalis.
Phase II Medicine- Blood Module - May 2008

3. Clinical significance of determination of blood groups
At least 30 commonly occurring antigens (Ag) have been found on the cell membrane of RBCs.
These can cause Ag-Ab reaction if mixed with plasma that contain antibodies (Ab) against these Ag.
2 groups of Ag can cause transfusion reactions more than others: ABO and Rh systems.
Phase II Medicine- Blood Module - May 2008

4. ABO Blood Groups A and B Antigens- Agglutinogens
Phase II Medicine- Blood Module - May 2008

5. Phase II Medicine- Blood Module - May 2008
ABO Blood Groups
Relative frequency of different blood types:
O 47%
A 41%
B 9%
AB 3%
Phase II Medicine- Blood Module - May 2008

6. Phase II Medicine- Blood Module - May 2008
Agglutinins
Blood type
Agglutinogen on RBC
Agglutinin in plasma A
Anti-B B
Anti-A AB
A and B
None O
Anti-A and Anti-B
Phase II Medicine- Blood Module - May 2008

7. Phase II Medicine- Blood Module - May 2008

8. Phase II Medicine- Blood Module - May 2008
Rh Blood Type
If type D antigen is present on RBC  Rh +ve
Differences between ABO and Rh Ab?
Anti-Rh antibodies are not naturally occurring Ab.
Previous exposure to Rh antigen is required.
Rh +ve blood transfusion.
Rh –ve women pregnant with Rh +ve baby.
Anti-Rh Ab can cross the placenta.
Phase II Medicine- Blood Module - May 2008

9. Phase II Medicine- Blood Module - May 2008
Blood Grouping
Phase II Medicine- Blood Module - May 2008

10. Blood grouping, showing agglutination of cells of the different blood types with anti-A or anti-B agglutinins in the sera
Red blood cell types
Anti-A serum
Anti B serum O - A + B AB

11. Phase II Medicine- Blood Module - May 2008

12. Phase II Medicine- Blood Module - May 2008

13. Phase II Medicine- Blood Module - May 2008

14. Phase II Medicine- Blood Module - May 2008

15. Phase II Medicine- Blood Module - May 2008
BLOOD TRANSFUSIONS
Phase II Medicine- Blood Module - May 2008

16. Phase II Medicine- Blood Module - May 2008
Blood Transfusion
Indications.
Types:
Heterologus
Autologous
Phase II Medicine- Blood Module - May 2008

17. Phase II Medicine- Blood Module - May 2008
Universal Donor.
Most hospitals have available group O negative blood for use in extreme emergency situations.
Group O negative is considered as universal donor.
Phase II Medicine- Blood Module - May 2008

18. Transfusion Reactions resulting from mismatched blood types
Agglutination and delayed hemolysis of donor’s RBC (or immediate intravascular hemolysis)→ Jaundice
Phase II Medicine- Blood Module - May 2008

19. Phase II Medicine- Blood Module - May 2008

20. Common Hazards of Blood Transfusion
Acute transfusion reactions occurring within 72 hours:
Immunological reactions :
Haemolytic transfusion reaction
Allergic reactions eg. urticarial reaction
Non immunological reaction:
Circulatory overload
Delayed transfusion reactions occurring after 72 hours:
Iron overload
Renal tubular blockage by haemoglobin
Renal failure
Phase II Medicine- Blood Module - May 2008
Phase II Medicine- Blood Module - May 2008 20

21. Diseases transmitted by blood transfusion
Viral hepatitis
HIV / AIDS
Other transmissible diseases are syphilis, malaria, CMV etc.,
What do you do to prevent this?
Phase II Medicine- Blood Module - May 2008
Phase II Medicine- Blood Module - May 2008 21

22. Pre-transfusion Tests
For a safe blood transfusion, the following tests are done:
Blood grouping
Cross-matching
Phase II Medicine- Blood Module - May 2008

23. X-matching
Once patient’s blood group is known, donor blood of the same ABO and Rh type is selected.
Possible donor RBC’s are mixed with the recipient’s serum. If no agglutination, no Ab in recipient blood will attack donor’s RBCs.
Phase II Medicine- Blood Module - May 2008
Phase II Medicine- Blood Module - May 2008 23

24. Haemolytic Disease of the Newborn (HDN)
Rh incompatibility  Erythroblastosis Fetalis (HDN).
Rh –ve lady marrying Rh+ve man.
If baby is Rh+ve, fetal RBC leaks to maternal circulation during placental separation (delivery or abortion).
Mother starts to make anti-Rh Ab.
Next pregnancy with Rh+ve baby  anti-Rh Ab pass to baby and cause agglutination and hemolysis of his RBC.

25. Phase II Medicine- Blood Module - May 2008

26. Phase II Medicine- Blood Module - May 2008
HDN
Clinical picture:
Anemia→ Jaundice
Hepatosplenomegaly
Kernicterus (mental
impairment due to precipitation of bilirubin in brain cells)
Phase II Medicine- Blood Module - May 2008

27. Phase II Medicine- Blood Module - May 2008
Prevention
Anti-D antibodies (RhoGam) injection given to Rh –ve mothers after delivery of Rh +ve baby.
Phase II Medicine- Blood Module - May 2008

28. Phase II Medicine- Blood Module - May 2008