Immunohematology-blood banking-Dr Fung Flashcards
What is this:
the collection, processing, storage and distribution of whole blood and apheresis derived blood and blood components.
Blood banking
occurs at blood collection facility or blood center
What is this:
pretransfusion and compatibility testing, post-manufacture processing. Occurs predominantly at a hospital
Transfusion medicine
What is the major test to test for blood type?
agglutination
What is this:
used for blood bank testing
- Immediate spin (i.e. take patients blood and mix it with IgM antibodies and check for agglutination)
-again at 37 celcius
-IAT phase (detects RBCs coated with IgG +/- complement)
Tube testing
What antibodies are significant in tube testing?
IgG (not IgM)
In tube testing, if there is not agglutination where will the fluid be in the tube?
At the bottom (more agglutination towards the top)
(blank) determines in vivo agglutination
(blank) determines in vitro agglutination
DAT
IAT
The (blank) reflects in vivo antibody sensitization of erythrocytes. Erythrocytes are washed to remove any unbound antibodies, and anti-IgG AHG reagent is then added. IgG antibodies cannot cause direct erythrocyte agglutination, but if the erythrocytes are coated with IgG antibodies, the AHG reagent will cause them to agglutinate. This test can also be performed using anti-complement AHG reagent. If IgG antibodies are present, they can be eluted off the erythrocytes for specificity determination
DAT
direct agglutination test
The (blank) is used to detect the presence of IgG antibodies in serum (in vitro sensitization). Reagent erythrocytes are incubated in the presence of serum that potentially contains antibodies. If antibodies are present, they bind to their target antigens on the reagent erythrocytes. After the incubation period the erythrocytes are washed to remove unbound antibodies. Anti-IgG AHG reagent is added and will cause IgG-coated erythrocytes to agglutinate
IAT (indirect agglutination test)
What is this:
defined as “an inherited character of the red cell surface detected by a specific alloantibody”
blood group
Blood groups are organized into (blank)
blood group systems
What are blood group systems?
represents a single gene or cluster of two or more closely linked homologous genes
Currently there are (blank) recognized blood groups
297 belong to 33 systems
339
WHat are the proteins, glycoproteins and glycolipids found on RBCs?
ABO Rh secretory (Se,se) Lewis Kell Duffy Kid I MNS P
Why are blood groups clinically significant?
- hemoloytic tranfusion reaction
- hemolytic disease of the newborn/fetus
What are the most signif antibodies detection?
Require previous exposure
IgG
warm reactive (37 celcius)
WHat are the most insignif antibodies for blood group detection?
Naturally occuring
IgM
cold reaction (below 37 celcius)
(blank) cant cross the placenta this is why only IgG can give you hemolytic disease of the newborn
IgM
How to you get the ABO blood system?
you have type 1 and type 2 chains
What are type I chains?
glycoproteins and glycolipids free-floating in secretions and plasma
What are type 2 chains?
glycolipid and glycoprotein antigens bound to red cell membrane
Type I chains are found in the (blank)
saliva
(blank) gene modifies type I chains to produce H antigen (substance)
Se
(blank) gene modifies type 2 chains to produce H antigen (substance)
H
H antigen is further modified to make (blank) and (blank)
A antigen
B antigen
The (blank) antigen has no further modification of H antigen
O
What is the most important blood group?
ABO blood system
How is the genotype of the ABO blood system determined?
by three codominant alleles on the long arm of chromosome 9
What chromosome allows for the determination of the ABO blood system?
chromosome 9
Antigens are also carried on (Blank), (blank), (blank), (blank), (blank) (blank) and (blank)
platelets, endothelium, kidney, heart, lung, bowel, and pancreas
ABO antigens are present on fetal RBCs by (Blank) weeks of gestation and reach adult level by age 4
6
What are the most common blood types in caucasions?
A and O
What is the most common blood type in AA?
O
What are the most common blood types in asian?
O
WHat are the most common blood types in Native Americans?
O
What is bombay blood type?
Lack of H, A, and B antigens due to lack of H and Se genes (hh,sese)
(blank) are clinically significant and naturally occuring.
Antibodies
What do ABO antibodies do?
activate complement
immediate intravascular HTR
When do you get ABO antibodies?
appear at 4 months of age and reach adult levels at age 10
T or F
ABO antibodies may disappear with age
T
What are the three ABO antibodies?
Anti-A
Anti-B
Anti A,B
What will Group A blood make?
anti-B IgM antibodies that react strongly at body temperatures (37 celcius)
What will Group B blood make?
anti-A IgM antibodies that react strongly at body temperatures
What will Group O blood make?
Anti-A and anti-B IgG antibodies that react best at body temperatures
anti A, B IgG against A or B cells
Mild HDFN (most common)
How do you confirm a blood type?
with forward and reverse typing
Forward-(ex. A group agglutinates with anti-A)
reverse (ex. A group agglutinates with B cells)
When you are talking about positive or negative when discussing blood type you are referring to (blank)
Rh system
What is the second most important blood group?
Rh system
What are the 2 genes in the Rh system?
RHD (D/-)
RHCE (C/c, E/e)
RH(blank) makes most antibodies, then C and E
D
RH(blank) is very immunogenic, 80% of D-neg make anti-D
D
If you dont have your RH compatible, what will happen>
you will get hemolytic transfusion RXN with extravascular hemolysis
You can get severe hemolytic disease fetus newborn with (blank) and (blank)
anti-d and anti-c
You cant get mild HDFN with (blank) (blank) and (Blank)
anti-C, anti-D, anti E
ABO antibodies (need/dont need) previous exposure
dont need
RH antibodies (need/dont need) previous exposure
need
how do you typically get prototypical HDFN?
Not first pregnancy, unless mom was previously transfused
D-neg with D+ baby
How do you prevent HDFN with RH?
RHIG (commercially prepared anti-D)
WHen do you get anti-D and to whom?
D-neg females at 28 weeks gestation
D-neg females ≤72 hrs. of D+ baby’s birth
D-neg females with pregnancy complications or invasive procedure (amniocentesis, etc..)
WHen should you not give RhIG (anti-D)?
D-neg female who already has anti-D
D+ females
D-neg mom with D-neg baby
What is the RhIG dosage?
One full dose vial (300µg) per 30 ml of D+ whole blood
One full dose vial (300µg) per 15ml D+ RBCs
How do you determine percentage of fetal-maternal hemorrhage?
Fetal blood screen: qualitative
Kleihauer-Betke; quantitiative but poorly reproducible
Flow cytometry-quantitative and more accurate
Wha tis the KB percent?
the number of fetal cells in the adult blood
How do you calculate the amount of rhogam to give (RhIG)?
you take KB% and mutiply it by blood volume then divide by 30! then if the number after the decimal is less than 5 round up once, if more than 5 round up twice
What is the lewis system?
similiar to ABO system
In secretors Leb most common
in non-secretors LeA most common
Insignificant, naturally occuring, cold-reacting IgM antibodies
What is the MNS system?
Consists of M N S antignes
Which part of the MNS system is this:
insignificant, naturally occuring, cold-reacting IgM
Anti-M and anti-N
Which part of the MNS system is this:
Significant, exposure requiring, warm-reacting IgG
Anti-S, anti-s, anti-U
What part of the MNS system is this:
rarely associated with severe HDFN
Anti-M
What blood group system is associated with cold agglutinin disease and mycoplasma pneumonia infections?
auto-anti I (big I) of the I system
What blood group system is associated with infectious mononucleosis?
Auto-anti i (lower case I) of the I system
In the I system, antigens are built on (Blank) types of chains.
2
Where do you find simple i chains?
neonates
Where do you find branched I chains?
adults
Are the I system blood groups significant?
no they are insignificant, naturally occuring, cold reacting IgM auto antibodies
Why is the P system important?
because the P antigen is the parvovirus B19 receptor
What is this:
antigen is receptor for various bacteria and toxins
Insignificant, naturally occurring, cold-reacting IgM
P antigen
What is associated with auto-anti-P?
Paroxysmal cold hemoglobinuria
Biphasic IgG autoantibody (bind cold, hemolyzes warm)
The (blank) system kills
Kidd
What is this:
Significant, exposure requiring, warm-reacting IgG (with IgM component)
Can fix complement with IgM component
Severe acute HTR possible
Delayed HTR, anamnestic, intravascular and severe
Mild HDFN
Kidd System
Which kell antigen is found in high frequency?
k (lower case)
What is the second most common non-ABO antibody?
Anti-K
Is anti-K signifcant?
yes, exposure requiring,warm reacting IgG
What is anti-k usually do to?
transfusion, not pregnant
Is anti-k (little k) common?
no uncommon due t high frequency of antigen
What can kell incompatibility lead to?
severe acute or delayed, extravascular HTR
severe HDFN
What is Mcleod phenotype/McLeod syndrome?
All kell antigens decreased
hemolytic anemias
X-linked chronic granulomatous disease
What wil you see associated with the hemolytic anemias found in McLeod syndrome?
acanthocytes, myopathy, ataxia, peripheral neuropathy, cardiomyopathy
What are the duffy alleles?
FyA and FyB
Which is more common, anti-Fya or anti-Fyb?
anti-Fya
Is duffy signif?
yes signif, exposure requiring, warm reacting IgG
What can Duffy result in?
Severe HTR, delayed and extravascular
Mild, but occasionally severe HDFN
What is the most common phenotype in AA of duffy? Whats chill about this phenotype?
Fy (a-b-)
they are resistant to plasmodium vivax and P, knowlesi infection
Can you donate blood if you had a history of babesioisi or chagas?
no
Can you donate blood if you have been given growth hormone?
no
Can you donate blood if you have been givin insulin from bovine sources?
no
Can you donate blood if you had viral hepatitis before 11th birhtday?
yes but not after!
What are causes for a three year deferral for blood donation?
Recovered from malaria
Immigrants from malaria endemic areas (5 years of living)
Medication teratogens: Soriatane
What is cause for one year deferral for blood donation?
needle stick sex w/ HIV or hep Sex with IVDrug Abusers rape prostitution alogenic blood transfusion allogeneic transplant tats piercing syph travel to malaria place rabies vac travel to iraq
When can a pregnant women donate blood?
cant, not till 6 weeks postpartum
What results in a 72 hour deferral?
dental work
What results in a 2-4 week deferral
immunizations
What drugs result in deferrals?
Accutaine, finasteride: 30 days
Duasteride: 30 days
Aspirin: 48 hrs.
Plavix or Ticlid: 2 weeks
How much blood do you take for testing?
500ml
What tests do you do on blood to make sure its safe for donation?
ABO/RH Antibody screen Anti-HTLV I/II West Nile Virus NAT Anti-Trypanosoma cruzi (Chagas) Serologic syphilis -RPR/VDRL -FTA-ABS Hep B, Hep C, HIV
What organism has the highest risk of being in the blood?
HIV-2, WNV, Bacteria, Hep B
What organism has the least amount of risk of being in th eblood?
HTLV-1
Prepoerative autologous blood donation has (less/more) screening than alogenic
less duh cuz its your own blood
If you take blood to use on yourself but you dont use it all, can you give it to other patients for use?
no
How do you do pre-transfusion testing?
serum or plasma; q3 days and retained for 7 days
- records check
- ABO/Rh testing
- Antibody screening
What is a major crossmatch?
recieipents serum with donor RBCs (common)
What is a minor crossmatch?
donor serum with recipients RBCS (rare)
If you have a patient that is bleeding what do you give htem?
cryoprecipitate (factor 8 and fibrinogen)
What blood component gets the most bacterial infections and why?
plateltes because they are stored at room temp
How do you give RBCs?
with normal saline, ABO compatible plasma and 5% albumin
When do you see a rise in HCT and HGB after given a back of RBC and by how much?
15 minutes after transfusion
HCT 3%
HGB 1%
If given a back of platelets how much should it rise and by when?
by 20,000-30,000 in an hour
Does platelet transfusion require crossmatch ro ABO compatibility?
no
What is this: reduce the number of WBCs in the blood product (filters)
leukoreduction
What can washing do? and when do you use it?
remove 99% of plasma
in IgA deficiency
What are the four ways to modify blood components?
leukoreduction
washing
freezing
irradiation
What does irradation do?
deactivates T lymphocytes
Whend would you use irradiation?
-immunosuppresion
-intrauterine transfusions, neonatal transfusions
-hematalogic malignancies
-granulocyt transfusion
-recieving blood from first degree relative donor
receiving HLA-matched units
(blank) is used to prevent graft versus host disease
irradiation
An acute transfusion reaction occurs within (blank) hours
24
A delayed transfusion reaction occurs after (blank) hours
24
Transfusion reactions can be either (blank) or (blank)
acute or delayed
What are all the febrile acute transfusion reactions?
acute hemolytic
febrile non hemolytic
transfusion related sepsis
TRALI
What are the acute transfusions reactions NON-febrile?
allergic
hypotensive
transufion-associated dyspnea
TACO
What are all the febrile delayed transfusion reactions?
delayed hemolytic
TA-GVHD
What are all the delayed non-febrile reactions?
delayed serologic
post-transfusion purpura
iron overload
What are the signs and symptoms of an immune acute hemolytic transfusion reaction?
What causes this reaction?
-abdominal, chest, flank or back pain
-pain at infusion site
-feeling of impending doom
-hemoglobinemia
-hemoglobinuria
-renal failure/shock
-DIC
TYpe II hypersensitivity reaction mediated by IgG/IgM
What are the non immune signs and symptoms of acute hemolytic transfusion reactions?
What causes this reaction?
asymptomatic hemoglobinuria
Chemical or mechanical damage to blood product
Explain what happens with an intravascular acute hemolytic transfusion reaction?
There is ABO incompatibility
ABO antibodies fix complement and leads to rapid lysis
Also seen with other antibodies (Kidd)
What is this:
Usually (but not always) less severe due to lack of systemic complement and cytokine activation
Seen with Rh, Kell, Duffy antibodies
Extravascular acute hemolytic transfusion reaction
What is the treatment for acute hemolytic transfusion reaction?
Hydration/diuresis
exchange transfusion
If you think a patient is having a reaction to the transfusion what is the first thing you do?
STOP THE TRANSFUSION
What should you transfusion reaction work up be like?
stop transfusion
- clerical check (look at bedside paperwork/bag check, check blood bank paperwork, computer check)
- Draw post-transfusion sample (look for visible hemoglobinemia, compare to pre-transfusion sample)
- Do a DAT
- repeat ABO/Rh testing
Why would you want to do a DAT in a transfusion reaction work up and what does it tell you?
to demonstrate RBC coating with IgG and/or complement in vivo
Doesnt really prove anything because a positive DAT does not prove AHTH and a negative DAT does not disprove AHTR
What is the most frequently report transfusion reaction?
febrile non-hemolytic transfusion reaction
What is the major symptoms of febrile non-hemolytic transfusion reaction?
unexplained increase in temp 1 degree celcius
What is the etiology of febrile non-hemolytic transfusion reaction?
increased pyrogenic substances from WBCs
Pretransfusion: donor WBCs secrete cytokines in storage bag
During transfusion: recipient antibodies attack donor WBCs or vice versa
What is the treatment for febrile non-hemolytic transfusion reaction?
antipyretics
demerol
Allergic reactions caused by transfusion can be grouped into what three categpries?
Mild, moderate, severe (anaphylactic)
What are the symptoms caused by mild allergic reaction?
very common localized hives angioadema mild respiratory symptoms mild laryngeal edema
What are the symptoms caused by moderate allergic reactions?
stridor hoarseness wheezing chest tightness dyspnea
What are the symptoms caused by severe (anaphylactic)?
uncommon
- anaphylaxis very early
- hypotension
- lower airway obstruction
- abdominal distress
- systemic crash
- urticaria
- puritis
What is the mechanism behind a mild allergic transfusion reaction?
-Type I (IgE mediated) hypersensitivity to transfused
plama proteins
-Mast cell secretion of histamine and other mediators of allergic reactions
What is the treatment/prevention for mild allergic reactions?
Diphenhydramine IV or oral (prevention)
- Wash blood products
- may restart transfusion after hives clear
What is the mechanism behind a moderate allergic transfusion reaction?
type I (IgE mediated) hypersensitivity to transfused plasma proteins -mast cell secretion of histamine and other mediators of allergic reactions
What is the treatment for moderate allergic transfusion reactions?
Diphenhydramine IV
Epinephrine
What are the mechanisms behind a severe allergic (anaphylactic) transfusion reaction?
IgA deficient recipient with IgE anti-IgA
- haptoglobin deficiency
- latex drugs or foods in donor can leads to severe reactions in recipients
How do you treat/prevent a severe allergic (anaphylactic) transfusion reaction to a blood transfusion?
wash blood products
IgA deficient blood products
benadryl with corticosteroids
epinephrine
What is this
an extravascular hemolysis at east 24 hours but less than 28 days after transfusion
Delayed hemolytic transfusion reaction
What is the etiology of a delayed hemolytic transfusion reaction?
anamestic response
primary response
What is the anamnestic response in a delayed hemolytic transfusion reaction?
- antibody formed but fades over time
- anamnestic rapid production of IgG antibody
- Typical for Kid, Duffy, and Kell antibodies
What is the primary response in a delayed hemolytic transfusion reaction?
antibody is quickly formed and attacks still circulating transfused red cells
What is a transfusion associated graft vs. host disease (TA-GVHD)?
attack on recipient cells by viable T-lymphocytes in transfused blood product
What are the symptoms associated with TA-GVD?
- fever 7-10 days post-transfusion
- face/trunk rash that spreads to extremities
- mucositis, nausea/vomiting, watery diarrhea
- hepatitis
- pancytopenia
What patients are at risk for transfusion associated Graft Vs. Host disease (TA-GVHD)?
all those requiring irradiation
What is the treatment for transfusion associated graft vs host disease (TA-GVHD)?
irradiate blood products
What is cool about allergic transfusion reactions?
you can restart the transfuion after treatment
What is this:
- acute non-immune transfusion reaction
- due to bacteria in contaminated platelets and RBCs
- staph, strep, yersinia, bacillus, psuedomonas, e.coli
Transfusion associated sepsis
What is this:
similiar to severe allergic reaction butno skin symptoms, no GI or respiratory issues
-greater than 30mm Hg drop in systolic B, Diastolic less or equal to 80
-occurs less than 15 min after starts; resolves less than 10 after stop
-associated with patients taking ACE inhibitors or receiving blood with negativey charged filters
Hypotensive
What is this:
acute onset of congestive heart failure as a direct result of blood transfusion
Transfusion associated circulatory overload
What is this:
rare
-mrked thrombocytopenia and ncreased risk of bleeding 10 days following transfusion
-due to antibody against a common platelet antigen (anti-HPA-1A, PL has a frequency of 98%)
Post transfusion purpura
In extravascuar hemolysis what will you see?
increased LDH, Increased reticulocyte count, increased indirect bilirubin and derease haptoglobin.
In intravasculr hemolysis what will you see?
super increased LDH, VERY low haptoglobin, increased reticulocyte count (thanks to kidney sensing hypoxia and increasing EPO). Hemoglobin in urine. Iron deficient, cuz of hemoglobinuria (doesn’t happen in extravascular hemolysis)
You can have a low (blank) iN SEVERE CHRONIC iron sufficiency anemia because you don’t even have enough iron to stimulate creation of reticulocytes.
reticulocyte count
If you have an LDH above (blank), then it is intravascular hemolysis.
1000
If you see petechia then it is only seen in (blank)
intravascular hemolysis
If your bilirubin is normal it is not (blank)
hemolysis