Card Set Information
What is immunohematology
What is titration
a method to determine the highest dilution at which agglutination can be detected.
What are applications of TITRATION
-Monitor maternal IgG antibody
-CAS (Cold Agglutinin Syndrome)
Application of Titration
What does Titration of maternal IgG antibody entail?
an indicator of the course and severity of hemolytic disease of the fetus and newborn(HDFN).
-Fourfold rise or greater is considered significant
What value is given to pathologic cold agglutinins
What Describes a group of weakly reactive, IgG antibodies that have the unique characteristic of reacting indilutions as high as 1:2048
HTLA (High titer low avidity antibody)
Anti-Ch, -Rg, -Cs
, - Kn
all have what in common?
-HTLA (High Titer Low Avidity antibodies)
-Reacts with many cells – difficult to rule out other abs
-These are IgG antibodies but are often NOT clinicallysignificant but may mask other antibodies.
What is neutralization?
Inactivation of an antibody resulting from binding with a soluble antigen.
What are the known substances that have blood group antigen specificity?
Hydatid cyst fluid – P1 substance
Human urine - Sda
Human serum – Ch, Rg
Human breast milk - I
What is Adsorption?
-to remove antibody from a serumsample by combining it with antigen positivered cells
What are some applications of Adsorption?
-Separate multiple antibodies in a single serum sample.
-Remove autoantibody from a sample to permitdetection of alloantibodies.
-Remove unwanted antibody from a serum with anantibody suitable for reagent use. ---
-Confirm the presence of an antigen on a red cell sample by its ability to remove the corresponding antibody from a sample.
-Confirm the specificity of an antibody by showing it canbe adsorbed onto a red cell of known antigen type
What are the 2 methods of Adsorption of Antibodies?
-Homologous (Allogeneic) adsorption
When is Autologous Adsorption used?
When the patient has not been transfused recently.
When is Homologous Adsorption used?
used when apatient has been transfused recently
Why cant auto cells be used for Homologous Adsorption?
because you may adsorb alloantibody onto circulating donor cells
What cells are used for Homologous Adsorption?
Use red cells of known phenotype to adsorb out the broad specificity autoantibody.
-Usually 3 different cells: R
, rr,lacking Jk
, K and s antigens
Why do we enzyme treat cells in Homologous Adsorption?
-to make them Fy
and S antigen negative.
What is Elution?
-is a technique used to free the antibody bound to the red cell membrane.
What are the methods of Elution?
1.Temperature: heat or freeze/thaw
-Investigation of ABO system antibodies
2.Acid or organic solvents
-Investigation of warm reactive allo or autoantibodies
-What causes a positive DAT following a transfusion reaction?
-Mixed field DAT due to donor cells in the recipient’s circulation that are coated with IgG
-Eluate is used to identify the alloantibody coating thedonor cells
What is associated with to Investigate a positive DAT in a patient with warmautoimmune hemolytic anemia
Characterize the antibody
What is associated with In combination with adsorption procedures?
-Detect weak antigen
-Recover adsorbed antibody