Blood Bank II Unit #1.3

Transfusion History

prior transfusions increase alloimmunization risk and explain newly detected antibody

Pregnancy History

pregnancies can trigger alloimmunization to paternal/fetal antigens

Diagnosis and Medications

autoimmune conditions and certain drugs can produce autoantibodies or drug-dependent antibodies that mimic alloantibodies

Prior Antibody Record

check for previously identified antibodies that may now be too weak to detect but still require neg blood

Rule Out

negative reaction with positive cells

Homozygous

an antibody showing double dosage will react stronger

Anti-D exception

when Anti-D is present, two heterozygous cells may be used for C and E

Anti-c exception

two heterzygous reactions may be used to rule out E

Rule of Three (95%)

three ag pos cells must react and 3 ag neg cells must not react

Antibody to High Frequency Anitgen

most or all panel cells react and autocontrol stays neg

Antibody to Low Frequency Antigen

antibody screen is neg, but XM is incompatible

Antigen Typing

confirms that a patient is neg for corresponding antigen

Antigen Type Control

positive must be heterozygous for applicable antigens

Electronic Computer

computer logic verifies ABO compatibility using 2 previous determinations on record

Immediat Spin

detects ABO incompatibility only, spun at RT

AHG (full)

carries donor cells through IAT to detect clinically significant antibodies. Read at all 3 phases and detects clinically significant antibodies