Week 3 Flashcards
antigens that are coded by different alleles of a single gene are referred to as.
antithetical alleles
Antigens from inherited alleles are expressed is describing
codominant alleles - most antigens are codominant
Null phenotypes result from inheriting 2 amorphic recessive alleles is describing
silent or amorphic alleles
Some antigens have regulator or modifying genes which can…..
- Alter gene expression
* May act across multiple blood group systems
Genes are written in
- Written in italics
* Le, Se, H genes (this should be in italics)
Antigens are written with…….
a combination of upper and lower case +/- superscript
Phenotypes are written with……
- Plus sign or minus sign used to designate presence or absence of an antigen.
- K-k+
- Le(a+b-)
- M+N-
Antibodies are written with……
- Antigen notation with prefix “anti-”, including a hyphen before the antigen symbol • Anti-K
- Anti-Lea
- Anti-M
Cold reacting antibodies react best at what temps? and are they usually IgG or IgM?
- Reacts best at room temperature or below
* Usually IgM
Warm reacting antibodies react best at what temps? and are they usually IgG or IgM?
- Reacts best at 370C
* Usually IgG
What is meant by clinically significant?
Antibodies that are associated with decreased red cell survival - can cause transfusion reactions or HDNB
What is meant by dosage?
- Observe stronger agglutination when a red cell antigen is expressed from homozygous genes
- Eg. Jk(a+b-) or Jk(a-b+) will exhibit stronger agglutination than Jk(a+b+)
What does the Direct anti-globulin test detect?
antibodies bound to red cells
What does the Indirect anti-globulin test detect?
antibodies in the plasma
What is the Enzyme phase?
Enzymes can be used to enhance reactions in the lab
Apart from ABO and Rh antibodies, what is most common Ab seen in blood bank?
anti-K
From the Kell system
Complement can cause the in vivo destruction of rbc following an incompatible blood transfusion if the antibody involved can bind C3 or C9.
Just be aware
Kell system and Anti-K Clinical Significance? Antibody class? HDNB? Optimal Temp? (Warm or Cold) Effect of Enzymes? Dosage?
Clinical Significance? Yes Antibody class? IgG HDNB? Yes Optimal Temp? (Warm or Cold) Warm Effect of Enzymes? No effect Dosage? occasionally
The Kidd System antibodies Clinical Significance? Antibody class? HDNB? Optimal Temp? (Warm or Cold) Effect of Enzymes? Dosage?
Clinical Significance? Yes Antibody class? IgG HDNB? rarely severe Optimal Temp? (Warm or Cold) Warm Effect of Enzymes? enhanced Dosage? yes
The Duffy System Antibodies Clinical Significance? Antibody class? HDNB? Optimal Temp? (Warm or Cold) Effect of Enzymes? Dosage?
Clinical Significance? yes Antibody class? IgG HDNB? Yes Optimal Temp? (Warm or Cold) Warm Effect of Enzymes? no effect Dosage? yes
Are Anti M and Anti-N clinically significant?
Only if they react in AHG at 37c. Otherwise no
displays dosage
S and s antigens Clinical Significance? Antibody class? HDNB? Optimal Temp? (Warm or Cold) Effect of Enzymes? Dosage?
Clinical Significance? yes Antibody class? IgG HDNB? Yes Optimal Temp? (Warm or Cold) Warm Effect of Enzymes? Variable Dosage? Yes
What are the 4 blood group systems that are most clinically significant?
Kell
Duffy
Kidd
MNS
List 4 blood group systems that are sometimes Clinically Significant
Lewis
Lutheran
P
I
