HDN/HTR/QA Flashcards
What is hemolytic disease of newborn (HDN)?
Destruction of fetal or neonate RBC’s by antibodies produced by the mother
Caused by IgG antibodies
What blood bank tests are typically completed on all pregnant women?
Type and screen, Du (weak D) testing
What process is occurring in the fetus to compensate for the maternal antibody destruction of RBCs?
Kernicterus increases. Hematopoietic tissue, fetal bond marrow, spleen, and liver increase RBC production as anemia increases due to mother’s antibody.
What may be done to evaluate the severity of HDN during pregnancy?
Amniocentesis or cardocentesis.
What blood bank tests should be done on all cord bloods, when HDN is suspected?
ABO grouping, Rh typing, DAT
elution - antibody ID if necessary
What further tests may be helpful if the baby is sensitized?
Bilirubin
What criteria must blood meet in order to be suitable for an exchange transfusion for a fetus or newborn?
Group O RBCs, gamma irradiated to decrease GVHD, antigen for mother’s antibody, CMV neg, blood < 7 days old.
What specimen do you use for crossmatching in a fetal transfusion?
Mother’s serum
Why should cord cells be washed 4 times before testing for ABO, Rh, and DAT?
To remove Wharton’s jelly, which will cause false positive agglutination
What screening test can be done to detect fetal blood in the mother’s post delivery specimen?
Rosette technique
What is the theory behind the rosette screen for fetal RBCs?
A sample of the mother’s blood is mixed with anti-D. The anti-D attaches to the fetal D pos cells, which makes it invisible. O pos cells are added that attache to the anti-D on the fetal cells, making a circle around them (a Rosette). A pos test indicates a large fetal bleed into the mother’s circulation
What quantitative test can be completed to determine how many fetal cells are in the mother’s serum?
Confirmation test such as Kleihauer-Betke for quantitation
What is the shelf life and storage temp for RhIg?
2 years at 1-6 degrees
What else can be done to quantitate fetal bleed into the mother’s circulation besides the Kleihauer-Betke test?
Flow cytometry
Which immunoglobulin class can cross the placenta and enter a fetus’ circulation?
IgG 1-4
When are multiple doses of Rh immune globulin indicated?
Confirmatory test - Bleihauer-Betke pos
Why are antibodies titered? When is this important?
Antibodies are titered in the mother to give a relative # of antibodies that are crossing the placenta and also to see if the titer is increasing
Why must the RBCs be standardized for each antibody titer?
The RBCs used for each titration should be from the same donor, approximately same storage time & same concentration. The 1st serum specimen should be frozen and done in parallel with each subsequent titer
A babe is found to have a pos DAT. How would you interpret?
Elution - antibody ID
What would you do if the mother was a pos for weak D and had a negative FMH screen?
No work up
What would you do if the mother has a negative weak D and pos FMH screen?
Quantitate by Kleihauer-Betke or similar technique
What is the incidence of forming anti-D for an Rh negative mother giving birth to an Rh positive baby?
9%
In HDN, the greatest risk to the newborn after 24 hours is ?
Hyperbilirubinemia
The most frequently seen cause of HDN is:
anti-A, anti-B, anti-A,B
One of the most severe cause of HDN is:
anti-D
Why isn’t anti-Le(a) associated with HDN?
Most anti-Le(a) are IgM so they don’t cross the placenta and if they are a rare IgG, the Lewis antigens are not well developed on fetal or newborn RBCs
List the blood group systems that are rarely involved with hemolytic disease of the newborn or fetus
Lewis, P, MN
If a fetus or newborn has a positive DAT, what are the next steps to be don before a transfusion?
Elution, antibody ID, blood selection that is CMV neg, irradiated and without the corresponding antigen involved, crossmatch
How many vials of RhIg should be administered if the mother had a positive Rosette test and no fetal cells were seen on Kleihauer-Betke slide?
One
What is the principle of the Kleinhauer-Betke test for fetal maternal bleed?
Maternal blood smear is treated with acid & then stained with a counterstain. Fetal cells (containing Hgb F) will remain pink because they are resistant to the acid. Mother’s cells will appear ghost-like. the % of fetal cells is calculated after 2000 cells are counted. From this, the volume of fetal cells in the mother’s circulation is counted
Which RBC antigens are not expressed on RBCs at birth?
Lewis, P, Lutheran
What class of antibody and temperature of reaction is the cause of the most sever intravascular transfusion reactions?
IgM broad thermal range, ABO
What signs and symptoms are occurring in the patient who is having a febrile transfusion reaction?
One degree C rise of temp over baseline temp during/within 24 hours after transfusion
One degree C rise of temp over baseline during/within 8 hours after transfusion
Probable causes: antibodies to human leukocyte antigens and cytokines in the unit of blood if not leukoreduced shortly after collection
What can be done to prevent further problems with febrile nonhemolytic transfusion reactions?
Better filtering out WBCs
Could use washed RBCs or deglycerized to remove all WBCs including fragments and cytokines produced during storage if not pre-storage leukoreduced
What signs and symptoms are occurring in the patient who is having an allergic transfusion reactions?
Erythema, pruritis, hives. Fevers may or may not be present
What can be done to prevent further problems with allergic transfusion reactions?
Removal of plasma with blood components (washed RBCs and platelets) and premedication with antihistamine
What signs and symptoms are occurring in the patient with immediate intravascular hemolytic transfusion reaction?
Immediate, pt frequently has fever, chills, oliguria. some experience anuria, coagulapathy and 1 out of 10 ie o hypotension
What signs and symptoms are occurring in the patient with delayed extravascular hemolytic transfusion reaction?
Fever, chills, jaundice, unexpected anemia, and decreased haptoglobin
What is transfusion-associated circulatory overload (TACO)? What is the likely cause?
Symptoms are seen when the patient’s cardiovascular system’s inability to handle too much volume occurs. Congesting heart failure signs and symptoms occur. Circulatory overload
What would the complication for a patient that has received frequent RBC transfusions over a life time?
Iron overload
What needs to be done to a unit of RBCs before issue them to a severely immunocompromised recipient?
Irradiated
What would possibly cause a physically induced transfusion reaction?
RBC hemolysis from heat damage
RBC hemolysis from freezing/washing process
Pushing donor unit too fast through transfusion needle - causing hemolysis
What is the most likely cause of transfusion related acute lung injury?
Donor antibodies to MHC antigens
What is the primary cause of post-transfusion purpura and a severe drop in the platelet count of the recipient?
Platelet antibodies HPA (Ia) in recipient
If a patient has a massive transfusion, what electrolyte may fall because of citrate toxicity?
Calcium
If a patient has antibodies to IgA, what type of transfusion reaction may occur?
Anaphylactic
If a person has anti-IgA and needs RBC products, what can be done to make a safe transfusion?
Wash the RBCs
