Compatibility testing is performed before blood transfusions to ensure the donor blood will (1) not harm the recipient, (2) function properly within the recipient, and (3) survive adequately in the recipient. The main compatibility factors considered are the ABO blood type antigens (A, B, and H) found on red blood cells and in bodily secretions, as well as antibodies that form in response to foreign antigens. A cross-match test is done to directly mix the recipient's serum with donor red blood cells to check for any antibodies that could cause the donor cells to be destroyed.

1. Topic: Compatibility
Submitted By Safdar Ali
Submitted To Dr. Waqar Ashraf

2. Compatibility
What is compatibility?
A state in which two things are able to exist or occur together without problems or conflict.
1) Blood Grouping (Forward & Reverse Grouping)
2) Cross-Match ( Donor Red with Patient Serum)

3. Purpose of Compatibility:
 PURPOSE Compatibility (i.e. Pre-transfusion) testing is performed to select
red cells that will
 i) not cause harm to recipient
 ii) have acceptable function in recipient
 iii) have acceptable survival in recipient

4. ABO Antigens:
ABO Antigens ABO antigens can be found on:
Red Blood Cells surface
Environment
Secretions

5. ABO Antigens on Red Cell Surface :
 The ABO blood group antigens are:
 I. A
 II. B
 III. H

6. Environmental Antigens

7. Formation of Antibodies:
 Formation of Antibodies against Red Cell Antigens Patients are transfused with
donor red blood cells.
 These donor red cells are different from recipients (patients) red blood cells
and thus are recognized by the recipient’s immune system as non-self i.e.
foreign for the recipient, like bacteria.
 Thus the body makes antibodies against these foreign antigens present on the
donor red cells which are absent in the recipient.
 Environmental Exposure.

8. Important Antibodies in Compatibility?
Two different kinds of antibodies can be formed in response to foreign red blood
cells. which are;
IgG IgM.

9. Secretions:
 Substance Some human body fluids contain soluble glycoproteins which have
antigenic determinants identical with red cell antigens. When antigens are in
solution, the term substance is applied.
 Thus there are A and B antigens on red cells, A and B substances present in
saliva and in other body fluids.

10. Blood group Compatibility:

11. Compatibility Testing (Cross-Match)
 Compatibility Testing Performed on Patient’s serum and Donor’s cells. For the final
confirmation of compatibility, patient’s serum is tested with donor red blood cells.
 This procedure is called Crossmatching, because patient’s serum is tested with the
donor red cells.
 There are three phases through which crossmatching have to be taken through.
 The three phases include:
 1) Immediate spin; Is performed to demonstrate ABO compatibility and to detect
IgM antibodies
 2) At 37 o C / Albumin (Enhancement media); This is performed to demonstrate
clinically significant IgG antibodies present in recipient serum to corresponding
antigen on donor cells.
 3) Antihuman Globulin (AHG) Phase: To demonstrate IgG antibodies in recipient
serum that may cause destruction of donor’s red cells.

12. Compatibility Chart For Pack Cells:

13. Compatibility Chart For Whole Blood:

14. FFP Compatibility: