Blood banking/immunohematology app Flashcards
Red Blood Cell Membrane
- Lipid bilayer
- Carbohydrate and proteins inserted
- > 300 antigens identified
ABO system
- Precursor H antigen (Bombay)
- Two glycosylated antigens (A and B)
- Four blood types (A, B, AB, and O)
- Naturally-occurring antibodies
Blood Typing
- Forward – patient red blood cells
- Reverse – patient serum
Donors and Recipients
Red Blood Cells
* Type O – universal donor
* Type AB – universal recipient
Plasma
* Type AB – universal recipient
* Type O – universal donor
Rh System
- Antigens – D, c, C, e, E (no d antigen)
- Rh-positive – D antigen present
- Antibodies not naturally-occurring (transfusion or
pregnancy)
Minor Red Blood Cell Antigens
- Kell (K/k)
- Duffy (Fya/Fyb)
- Kidd (Jka/Jkb)
- MNS (M/N; S/s/U)
- Lewis (Lea/Leb)
- Lutheran (Lua/Lub)
- P (P)
- Others
Blood Donation
- Interval - every 56 days (whole blood)
- Age - >16
- Height/Weight – 5’4”/110 pounds
- Feeling well
- Deferral indications
Deferral Indications for blood donation
- Low hemoglobin
- Donor medical history
- Medications
- Sexual history (HIV risk)
- Travel history
- Lifestyle factors
Whole Blood Components
- Packed red blood cells – 42 days, refrigerated
- Platelets – 5 days, room temperature
- Plasma – 1 year, frozen
Apheresis
- Selective removal of one component of blood (e.g.
platelets, plasma, white blood cells, etc.) - Donation versus therapeutic applications
Pre-transfusion Testing
- Blood type of recipient
- Blood type of donor
- Antibody screen on recipient
- Crossmatch
Transfusion Reactions
- Febrile versus non-febrile
- Any febrile reaction is potentially serious
- Immune versus non-immune
- Hemolytic versus non-hemolytic
- Immediate versus delayed
- Mild versus severe
Allergic Reaction
- Allergen in transfused blood reacts with antibodies in
recipient - No fever
- Immediate reaction, non-hemolytic
- Mild, usually local symptoms
- Antihistamines
Febrile Non-Hemolytic Transfusion Reaction
- Cytokines in stored blood
- Fever
- Immediate, non-hemolytic
- Usually mild
- Acetaminophen
Acute Hemolytic Transfusion Reaction
- ABO incompatibility (clerical error)
- Fever/chills, hypotension
- Immediate, intravascular hemolysis
- Severe (abdominal/back pain, respiratory distress,
hemoglobinuria, disseminated intravascular
coagulation, renal failure, circulatory collapse,
“impending doom”, death) - Aggressive medical therapy
Delayed Hemolytic Transfusion Reaction
- Undetectable recipient antibodies
- Fever
- Delayed, hemolytic
- Usually mild (jaundice, decrease in hemoglobin)
- Supportive management
Transfusion-Associated Circulatory Overload
- Volume overload due to transfusion
- No fever
- Immediate
- Moderate-severe (shortness of breath, cough, heart
failure) - Diuretics, respiratory support
Transfusion-Related Acute Lung Injury
- Anti-leukocyte antibodies from donor (especially
female donors), but normovolemic - Fever
- Immediate, non-hemolytic
- Severe (respiratory distress)
- Supportive care, 5-25% mortality
Transfusion-Associated GVH Disease
- Donor lymphocytes (“graft”) proliferate and attack recipient
cells (“host”) - Fever
- Delayed, non-hemolytic
- Severe (skin rash, hepatitis, diarrhea)
- Difficult to manage, >90% mortality
- Prevent by irradiating blood
Post-Transfusion Purpura
- Anti-platelet antibodies (PLA1) in recipient (mainly
females) - Fever
- Delayed, platelet destruction
- May be severe (thrombocytopenia, bleeding)
- Antigen-negative platelets, plasmapheresis
Transfusion-Transmitted Infections
- Overall incidence is very low
- Bacterial infection – 1 in 5,000 to 1/30,000
- HIV – 1 in 2,000,000
- Hepatitis B – 1 in 300,000
- Hepatitis C – 1 in 1,500,000
- West Nile virus – 1 in 350,000
- HTLV-1/2 – 1 in 3,000,000
Selective IgA Deficiency
- Decreased/absent IgA synthesis in recipient (anti-IgA
antibodies react with IgA from donor) - May have fever
- May be immediate
- Most asymptomatic, but risk for anaphylaxis
- IgA-negative donor, wash red blood cells to remove
plasma
Hemolytic Disease of the Newborn
- Incompatibility between mother and baby (mother
lacks an antigen expressed by baby) - Maternal antibodies cross placenta and cause
hemolysis in baby - Most often ABO or Rh
- ABO – usually mild, first pregnancy
- Rh – may be more severe, previous exposure
- Rh Immune globulin prophylaxis
Transfusion Indications
- Clinical evaluation rather than just numbers
- Red blood cells – symptomatic anemia
- 1 gm/dl hemoglobin rise per unit
- Platelets – significant bleeding, thrombocytopenia
- 30-60 x 103 platelet rise per transfusion
- Plasma – significant bleeding, coagulation defect
- 30% factor activity based on body weight and
plasma volume
Pre-Transfusion Testing Times
- ABO/Rh typing – 10 minutes
- ABO/Rh typing + antibody screen – 45 minutes
- ABO/Rh typing + antibody screen + crossmatch – 60
minute - Crossmatch only (no antibodies) – 10 minutes
Emergency Situations
- Type O, Rh-negative red blood cells (especially young
women) - Type AB plasma
- Massive transfusion protocol
- Prepared transfusion packs (red blood cells,
plasma, platelets) available immediately - Tranexemic acid (anti-fibrinolytic)
- Correction of metabolic derangements
What is the most appropriate next step to
take?
A. Wait for the results of the type and cross and order
two units of compatible packed red blood cells
B. Order 5 units of O-positive red blood cells and 5 units
of AB-negative plasma
C. Order 5 units of O-positive red blood cells and 5 units
of O-positive plasma
D. Order 5 units of A-positive red blood cells, because
you recall the patient’s blood type is A-positive
If the patient requires additional red blood
cell transfusions, which type of blood should
be administered?
A. Type A
B. Type B
C. Type AB
D. Type O
What is the most likely cause for these
findings?
A. Underlying auto-immune disease
B. Delayed hemolytic transfusion reaction
C. Acute hemolytic transfusion reaction
D. Transfusion-associated graft versus host disease
E. Blood bank error
What is the most likely explanation for the
presence of the antibody?
A. She is Rh-positive and the baby is Rh-negative
B. She is Rh-negative and received Rh immune globulin
C. She is Rh-negative and has an underlying
autoimmune disease
D. She is Rh-positive and recently had a tattoo applied
What is the most likely cause for the
observed febrile reaction?
A. Allergic reaction
B. Acute hemolytic transfusion reaction
C. Delayed hemolytic transfusion reaction
D. Febrile non-hemolytic transfusion reaction
E. Bacterial contamination
What is the most appropriate next step?
A. Examine the patient and when you find no problems,
continue the transfusion because this is likely a
repeat febrile reaction
B. Pause the transfusion, administer acetaminophen,
and then continue the transfusion if his temperature
decreases
C. Stop the transfusion and send a specimen to the
blood bank for further work-up
D. Call the transfusion center and tell them this is an
expected reaction and that there is no need to
further monitor his temperature
Case 3 (continued)
Despite your recommendations, the transfusion is
continued. Mr. Cooper now reports severe back pain,
burning around the infusion site, dizziness, and he says
“Doc, I feel really scared”. What is most likely cause of
these findings?
What is most likely cause of these findings?
A. Acute hemolytic transfusion reaction
B. Delayed hemolytic transfusion reaction
C. Transfusion-related acute lung injury
D. Septic reaction
E. Anaphylaxis
What is the most likely cause of these results?
A. Mr. Cooper got his wife’s blood, she is type A
B. Mr. Cooper got his wife’s blood, she is type O
C. The blood bank forgot to perform a crossmatch prior
to transfusion
D. The pre-transfusion sample was mixed up with that
from another patient
What is the most likely cause of these
findings and what is the most appropriate
next step?
A. Acute leukemia; leukapheresis
B. Sickle cell crisis; red blood cell exchange transfusion
C. Idiopathic thrombocytopenic purpura;
plasmapheresis
D. Thrombotic thrombocytopenic purpura; plasma
exchange
E. Autoimmune hemolytic anemia; plasmapheresis
Case 5
A 72-year-old man is admitted with GI bleeding. The
patient was on warfarin, so fresh frozen plasma is
ordered to reverse the effect of the warfarin.
Approximately 15 minutes into the transfusion, the
patient develops a rash, shortness of breath, periorbital
swelling, and quickly progressed to profound
hypotension and respiratory distress. What is the most
likely cause for these findings?
What is the most likely cause for these
findings?
A. Transfusion-associated circulatory overload
B. Transfusion-related acute lung injury
C. Septic reaction
D. Anaphylaxis
E. Acute hemolytic transfusion reaction
Which of the following is the most likely
cause of this reaction?
A. Anti-IgA antibodies in the recipient
B. Donor lymphocytes in the plasma
C. Anti-HLA antibodies in the plasma
D. Bacteria in the plasma
E. Anti-ABO antibodies in the patient
