Blood bank week 3

What are three types of immune hemolytic anemia.

-Alloimmune -Autoimmune -Drug induced

The most common cause of a Transfusion reaction is "clerical error". What 2 clerical errors are we talking about?

-Improper specimen ID -Improper patient ID

What is the advantage of an exchange transfusion for the baby?

-Removes sensitized cells -Lowers bilirubin -Removes maternal antibody -Replaces the incompatible RBC's

75. If a mom has a 1% fetal RBC in her circulation, how many vials of Rhogam should she get? What is the formula?

-The formula for Rhogam: %of fetal cells (5/3), round up or round down then add 1. -1X5/3=3 vials of rhogam.

Name 3 treatments used to treat patients with WAIHA without transfusing them.

-cortico steroids -splenectomy -immunosuppressant drugs

List the four methods that can be used to eliminate the interference of anti-I and "see underneath it". Which one of these eliminates IgM antibodies? Which one cannot be used if the patient has recently been transfused?

-pre warmed technique -auto adsorption: cannot be used if patient recently transfused. -REST adsorption: Rabbit Erythrocyte Stroma: can absorb anti-I -Treat serum with DTT: Destroys IgM by breaking disulfide bonds that hold together IgM antibodies but will not destroy IgG.

What other antibodies can cause HDN? Will Rhogam help prevent their formation?

Rh, Duffy, Kell and Kidd.

75. What is antenatal Rhogam, and why is it administered? Who should receive it?

Rhogam coats fetal RBC and removes stray D cells from circulation, shot of antibodies to D. D negative mothers who gave birth to a D positive baby. Prevent subsequent sensitation.

What should be done if a patient experiences urticaria (hives) during a transfusion? What antibody type is involved?

Stop transfusion and give Benadryl then resume transfusion. The antibody type involved is IgE in either donor or recipient

Describe TRALI. What does it stand for? Why might female derived donor components be more likely to cause TRALI? Did you know it is the most common cause of fatal transfusion events? You do now.

TRALI= Tranfusion Related Lung injury -A female who was recently pregnant may have these antibodies still in the circulation.

When working up a WAIHA, the MLS does a panel, and also does an elution of the +DAT. The eluate is tested against a panel as well. Is it possible that the serum panel and the eluate panel give different results?

Yes

75. Evaluate a Lilley Graph. Which zone indicates that the fetus is in immediate danger? What wavelength of light is absorbed by bilirubin?

Zones 3 indicates that the fetus is in immediate danger. 450 is the wavelength of light absorbed by bilirubin.

WAIHA are usually _(a)__ autoantibodies of the _(b)__ blood group. A common one to find is auto-anti-_(c)__.

a. IgG b. Rh c. e

Anti-H reacts more strongly with ___a___ cells, and less strongly with __b__ cells. This is why a patient who is A positive with anti-H will show a strong reaction with the panel cells and a weak reaction with the donor cells.

a. O b. A

Cold autoantibodies may be benign or pathologic. Anti-I interacts with all __a__ cells. Anti-i interacts with ___b___ cells.

a. adult b. Fetal

What is another name for the Donath Landsteiner antibody?

auto-anti-P

What type of TRXN occurs in IgA deficient patients?

Anaphylactic reactions

Which antibodies can fix complement and cause an intravascular TRXN?

Anti-A, K, Jka and Fya

75. Why is anti-Lea associated with pregnancy? Does it cause HDN? Does anti-P1 cause HDN?

Anti-Lea is very common in pregnant women, it does not cause HDFN. Anti-P1 does not cause HDFN

What is meant by the biphasic behavior of auto-anti-P1?

Auto anti P will bind to red cells and low temp but will lyse cells at body temperature.

What happens in an exchange transfusion?

Blood is prepared for the baby, some of the blood is removed then replaced in the baby.

True or false: if a patient has WAIHA, you can just ignore it because it won't lyse transfused blood.

False

Describe a febrile reaction. What is the likely cause of it? What processing step is in place to minimize febrile reactions?

Febrile reaction is a reaction to WBC, antibodies, and proteins of donor that causes a fever in the recipient. The cause of the febrile reaction is from blood not being leukodepleted. Leukodepletion is a way to prevent febrile reactions.

75. If a patient who is pregnant has a positive antibody screen, what is the follow up in the Blood Bank?

Follow up with amniocentesis and evaluate with bilirubin using delta OD 450.

What is the name of the federal agency that is responsible for the safety of the nation's blood supply?

Food and Drug Agency

List three reasons for a positive DAT

HDFN, Transfusion reaction and AIHA

HDN will affect the baby's lab values in a specific way. Complete the chart with "increase" or "decrease".

Hemoglobin: Decreased Hematocrit: Decreased Bilirubin: Increased Haptoglobin: Decrease Reticulocyte: Elevated DAT: positive

hemolytic anemia

Hemoglobin: decreased Hematocrit: decreased Bilirubin: elevated Haptoglobin: decreased Reticulocyte count: elevated DAT: Positive

In ABO HDN, is the Anti-A IgG or IgM?

IgG

How does one perform an autoabsorption? What is the advantage of doing one?

Incubates patient serum with cells pulls out autoantibody, phenotype then match donor cells. Less of a chance for a hemolytic reaction due to incompatibility

What routine tests are done on the mother after delivery? What tests are done on the infant? What tests are not necessary to do on the infant?

Mother: ABO/Rh, Ab screen. Cord: ABO/Rh, DAT, reverse type is not necessary

Anti-H may be a benign auto-antibody. It is also found in individuals with Bombay phenotype. Is it okay to give H positive blood to either of these groups?

No

75. ABO HDN can occur during the first pregnancy. Is this the case with Rh HDN?

No, usually occurs in the second pregnancy (D positive baby)

What is the typical case scenario for ABO HDN?

O mothers who had a A baby (whites), O mothers who have a B infant. (Blacks)

Describe Kernicterus, what is the danger to the infant?

Occurs when an infants bilirubin is so high that it gets into he nervous system and stains the brain. Neurological damage is the danger to the infant

Why does an older unit of blood have an elevated K+?

Older blood loses DPG and the sodium potassium ATP slows down hence elevating the K+

75. The first test done to determine how much Rhogam to give a woman after delivery is to do a Fetal Bleed Screen (Rosette) Test. If the FMBS is negative, how much Rhogam is administered?

One dose

75. One dose of Rhogam "covers" how much of a fetal bleed (state a volume of whole blood). This is not the same as packed cells. What volume of packed cells is covered?

One dose of Rhogam covers 30mL of whole blood. One dose of Rhogam covers 15mL of packed cells

What is PCH? It usually has the specificity of auto-anti-__P__.

PCH=Paroxysmal Cold Hemoglobinuria -following a infection in children -Specificity: auto-anti-P

How does one perform a DAT? There are 3 reagent sera used, what are they?

Performing a DAT: Make a 5% suspension, wash 4 times add polyspecific AHG check for agglutination, if positive start over with 2 tubes after washing add AHG to one tube add C3D to the other tube check for agglutination add check cells. The 3 reagents used is Polyspecific AHG, Monospecific AHG C3D AHG.

Type of Drug induced hemolysis a. Immune complex adsorbs to RBC b. Drug adsorption to proteins on RBC c. Membrane modification attracts complement and Immunoglobulins d. Autoantibody formation, e.g. Aldomet (methyldopa) use

Positive Reaction will be seen when patient serum is tested with ............... a. Drug b. Cells Coated with the drug c. eluate d. autoantibody

At what bilirubin level would Kernicterus be feared, e.g. what is the critical bilirubin level?

18 mg/dL

List 4 special conditions for blood that will be used for a fetal transfusion. What is the rationale for each?

1. Must be compatible with maternal antibodies because the fetus does not make antibodies. 2. The blood used must be CMV negative: newborns cant fight the CMV virus 3. Hemoglobin S negative: Reduced oxygen tension in utero, will cause cells to sickle (AS cells: sickle cell trait) 4. Less than 7 days: older blood loses DPG (infants cant replace DPG) and sodium potassium ATP slows down, possible hyperkalemia.

Bacterial contamination of a unit of blood can be deadly. Name 3 bacteria that are likely culprits.

1. Yersinia enterocolitica 2. Pseudomonas 3. E coli · Produce endotoxin in the cold

A fatal transfusion reaction must be reported to the FDA within how many days?

7 days after incident is detected

75. What is a "blocked Rh", sometimes seen on a baby's cells? What reaction will you see on the D type and the DAT?

A baby that is D positive has so much maternal anti-D coating the cell that the reagent anti-D cannot access the D sites. Rh will be negative with a positive DAT.

A patient received 2 units of blood after a transplant. This brought his H&H to 12 g/dL and 37%. He was discharged from the hospital. Three days later, he returns with a H7H of 7.0 g/dL and 22%. His DAT is positive. What do you suspect? What would you do next?

A delayed hemolytic transfusion reaction is suspected, to follow up perform a DAT, H and H, renal and coagulation studies, clerical check

75. Which type of HDN can cause infant cells to become spherocytes, ABO or Rh?

ABO

How are potassium and calcium values changed in a patient who has received a massive transfusion?

Can elevate potassium and decreased calcium.

Describe Cold Hemagglutinin's disease. What bacterial infection may precede it?

Caused by anti-I after exposure to the cold, may be caused after infectious mononucleosis

Rh antibodies can cause a delayed transfusion reaction. How does that work? What doesn't this cause intravascular hemolysis?

Delayed transfusion reaction happens when there are some antibodies that are amanestic so that the transfused cells will become coated and becomes sequestered causing the h and h to go down. The reason why this doesn't cause intravascular hemolysis is because complement isn't fixed

Describe the Kleihauer Betke test. How does it work? If the mother has HPFH, is the test valid? Why or why not?

During the Kleihauer Betke test a maternal blood smear is treated with acid and then stained with counterstain. Fetal cells contain fetal hemoglobin, resistant to the acid and will remain pink in color, the maternal cells will appear ghostly. After 2000 cells are counted the volume of fetal hemorrhage is calculated. One vial is added to the answer to determine the amount of Rhogam to give to the mother. If HPFH the test will not work.

When testing a DAT, why should the sample be collected in EDTA?

Inhibits complement activation so positive DAT, complement activation will happen in vivo.

What does irradiation of the blood unit do to it?

Irradiation kills or deactivates T cells preventing GVHD.

75. If the FMBS is positive, what test is reflexively ordered? Do you know what a reflex test means?

Kleihauer Betke, a reflex test is a confirmatory test.

75. How can you prove that HDN is caused by anti-A and not something else?

Maternal antibody is eluted from baby cord blood cells by elution, tests eluate against A1, B and screening cells. Will show reaction on A1 cells

75. Determine which mother/infant pair will require Rhogam:

Mother D+/Infant D+: No Mother D-/Infant D+ : Yes Mother D-/Infant D- :Yes Mother D+/Infant D- : No

Why would it be a BAD plan to use paternal blood for transfusion in HDN?

The antibody is most likely occurred from the paternal (fathers) RBC antibodies

75. If a fetus or newborn requires a transfusion, what blood type should be chosen? Why is it more important for the donor unit to be compatible with the mother than the infant? What special conditions must be imposed on the unit (name 3). What if not compatible blood is found, where might you look next for a donor?

The blood chosen must be compatible with the mothers' blood so the antibodies on the mothers red blood cells don't attack the fetal red blood cells. The blood must also be less than 7 days old, CMV negative and Hb S negative. If the blood is not compatible then the mother can be used as a donor, last resort.

Why should you NOT do an autoabsorption if a patient's RBC if they have been recently transfused?

The donor cells may be masking the patient cells

What is the initial check done in the Blood Bank to evaluate a suspected hemolytic TRXN? If the DAT is negative and the post transfusion serum is not hemolyzed, what should the MLS do? If those tests are positive, what should he do?

The initial check is do a clerical check of all printed materials then collect a lav and red top tube then look at serum color pre and post transfusion. Perform a DAT with C3d and IgG. If positive DAT do a dilution to identify antibody on hemolyzed sample. If DAT is negative on non hemolyzed sample do nothing more. If DAT is positive then perform an extended workup. Extended work up: -ABO/Rh -DAT on pre and post transfusion samples -urine: hemoglobin -Bilirubin: pre and post -H and H then haptoglobin

In HDN, whose antibodies coat the fetal RBC?

The maternal antibodies coat the fetal RBC

Hemolytic Transfusion reaction (TRXN) - what is the most common incompatibility that causes rapid hemolytic reaction? How does complement play a role in it?

The most common incompatibility that causes rapid hemolytic reaction is giving a type O patient A or B blood. The antibody fixes complement causing intravascular hemolysis which can be deadly

75. In cases of severe HDN due to anti-D, the cord blood will be DAT+ but D negative. Explain the possible reason for this reaction.

The reason why the cord blood will be D negative is because the amount of anti-D coating the fetal red blood cells causing a false negative because it cant be detected by the anti-D sera.

75. A newborn showed a strongly positive DAT. The mother's antibody as well as the antibody in the eluate prepared from this baby's cells reacted with all reagent red cells tested. The incompatibility was due to an unidentified antibody ( a private antigen to the father's cells). If the baby urgently needs a transfusion, what can be the source of the compatible blood?

The source can be from the mother

What is the time limit after delivery for administration of Rhogam?

The time limit of Rhogam administration after delivery is 72 hours.

75. Some women who received antenatal Rhogam will have an anti-D antibody after delivery. What titer suggests that the anti-D is "passive", e.g. from Rhogam?

The titer will be 1:2

75. A mother is Group A, D negative with anti-D. The father is Group O, D positive. Their newborn baby has a positive DAT with 4+ agglutination, and severe anemia requiring transfusion. The baby is A, weak D positive. These results only make sense if the weak D is a false result. What's causing the false positive weak D result?

The weak D false positive result could be from inadequate washing of whartons jelly.

What are the conditions that make a woman a candidate for Rhogam?

The woman must be D negative and weak D negative, infant is Rh positive.

How do you do a crossmatch for newborn transfusion? How long is it good for (how frequently does the antibody screen have to be done if the infant is to receive multiple transfusions over several weeks?

Use maternal serum or cord blood, can continuously be transfused because babies do not make antibodies.