rH Flashcards
Exposure to at least____ of Rh positive cells would stimulate antibody production of Rh negative persons
1 mL
Antibodies
Have been reported
Do not bind complement
IgG1, IgG2, IgG3, IgG4
How immunogenic is the Rh antigen?
• IF the mother, or someone is Rh negative/Rh null who is exposed to_______ of Rh positive red cells, it would stimulate antibody production
0.1 mL
Antibody transition will always start with___ - and then will develop to____
IgM
IgG
→ sensitized red cells - EASILY BE
ELIMINATED BY THE RETICULOENDOTHELIAL SYSTEM
It does not bind complement
IgG1 and IgG3
Rh antigens are disperesed in the plasma
membrane - they cannot stick together = thats why
majority of the hemolysis is_____ because it is mainly due to the reticuloendothelial system
EXTRAVASCULAR
Weak D
Difference between Rh negative and Rh null
• Rh negative =______
• Rh null =______
D is absent (C and E are present)
all are absent
is used to detect the presence of the D antigen.
Anti-D
Rh antigens are located in the_____
Hydrophilic heads, hydrophobic tails
• Rh glycoprotein is composed of_____ amino acids that traverse the plasma membrane____ times.
B/c this traverses nth times, it has something to do with maintaining the plasma membrane integrity of the red cell.
Rh null =_____ appearance
• Absence of Rh glycoprotein = integrity is weak
Rh glycoprotein
416; 12
stomatocyte
Weak D expression was historically known as______
Now referred as_____
Du phenotype
WEAK D POSITIVE
WEAK D
3 mechanisms:
- GENETIC WEAK D
- C TRANS
- PARTIAL D (Mosaic D)
How are you going to differentiate them?
- GENETIC WEAK D
- C TRANS
- PARTIAL D (Mosaic D)
Look on their genes (position/ if they have partial D)
RHD genes code for weaker expression of D antigen
Defective GENE
Because it is mutated/modified, there is reduced number of D antigens on the red cells
Genetic Weak D
• Most common in blacks (African-Americans)
Asians are Rh positive
Genetic weak D
is required to detect this form of D (GENETIC WEAK D)
Also known as_____
Included as a reagent are the Coombs’ check cells. (because simply they are Coombs check cells)
IAT (Indirect Antiglobulin Test)
Indirect Coombs Test
- Opposite side
- If RhD is on one
chromosome, RhCe is in another. - It has something to do with the weakened expression of
D antigen. - Mainly due to POSITIONAL EFFECT.
TRANS
Weak D position effect
- On the same side
- RhD and RhCe are on the same chromosome
- Normal expression of D
antigens - NO PROBLEM
CIS
Weak D position effect
One or more missing or altered epitopes of the entire D antigen
Partial D (D Mosaic)
If Rhull =
all antigens are missing
Required test for donors who are initially typed as D negative
Weak D Testing (IAT)
Rh antigens are disperesed in the plasma membrane - they cannot stick together = thats why
majority of the hemolysis is_____ because it is mainly due to the reticuloendothelial system
EXTRAVASCULAR
