Blood Component Compatibility Testing Prior to Transfusion

Red Blood Cells

Antibodies to red cell antigens occur naturally (against ABO) or can develop following pregnancy or transfusion. To obtain compatible blood and avoid potential hemolysis of transfused red cells, the Blood Bank performs a Type and Screen. It consists of:

1. ABO, Rh Type

The Blood Bank will provide ABO/Rh compatible blood.

Patient
(Recipient)
Compatible
Components
Blood
Group
Plasma
Contains
Red
Cells
O
Anti-A, Anti-B
O
A
Anti-B
O, A
B
Anti-A
O, B
AB
-
O, A, B, AB

Patients who are Rh(D) negative, commonly referred to as Rh- or D-negative, lack the D antigen. These patients routinely receive Rh(D) negative RBCs to prevent formation of antibodies against the D antigen. Anti-D can cause hemolysis and hemolytic disease of the fetus and newborn (HDFN).

If necessary, the Blood Bank may provide Rh(D) positive RBCs to Rh(D) negative females beyond child-bearing age and males. Rh(D) positive RBCs may be provided to premenopausal Rh(D) negative women in emergent circumstances; when this occurs, anti-Rh(D) immune globulin (RhoGam, WinRho) should be administered as soon as possible, at least within 72 hours, to prevent formation of anti-D.

Pediatric patients (less than four months): A single ABO type and screen is required before the first transfusion during the first four months of life.

2. Antibody Screen

The Blood Bank tests all prospective recipients for pre-existing unexpected red cell antibodies [e.g., antibodies to non-ABO antigens: Rh (C, c, D, E, e), Kell, Duffy, Kidd, etc.].

A type and screen is good for 72 hours. All patients who need blood must have a current type and screen.

When RBCs are ordered, compatibility testing (crossmatch) is performed.
  • If a RBC antibody is currently present or had been detected previously, a manual crossmatch is performed.
  • If no RBC antibody is present, an electronic crossmatch is performed.

Presurgical Screening: If the patient has been transfused or pregnant in the past 3 months, the type and screen is good for only 72 hours before surgery. The sample can be collected up to 30 days prior to surgery for patients who have not been transfused or pregnant in the past three months.

 CAUTION  For scheduled surgery it is essential to provide the type and screen specimen at least one day prior to surgery. If an antibody is found it may take up to 48 hours to identify the antibody and provide compatible units. This may delay surgery.

Prior to starting surgery, it is essential to confirm blood availability.

Platelets

Compatibility in platelets
  • A single donor platelet unit (SDP) unit is leukoreduced at the time of donation but contains some white blood cells (WBCs) and a negligible amount of RBCs.
  • Rh antigens are not present on platelets but may be present on RBCs. There is a small risk of Rh antibody formation if an Rh negative patient receives an Rh positive unit of SDPs. The best available component will be provided. 
  • A and B antigens are very weakly present on platelets. A small amount of plasma, present in the component, may contain antibodies to A and B antigens. These antibodies can cause minor hemolysis after transfusion. Generally, platelet transfusions are selected to be ABO identical or compatible, but mismatched ABO platelets can be given.
Patient
(Recipient)
Compatible Components
(in order of preference)
Blood
Group
Plasma
Contains
 
Platelets
O
Anti-A, Anti-B
O, A, B, AB
A
Anti-B
A, AB, B, O
B
Anti-A
B, AB, A, O
AB
-
AB, A, B, O

Plasma, Platelets, or Cryoprecipitate

An ABO/Rh type must be available to order platelets and plasma. For plasma and cryo, the Blood Bank provides components that are compatible. Platelets are selected to be ABO identical or compatible depending on availability.

Patient
(Recipient)
Compatible
Components
Blood
Group
Plasma
Contains
 
Plasma and Cryo
O
Anti-A, Anti-B
O, A, B, AB
A
Anti-B
A, AB
B
Anti-A
B, AB
AB
-
AB