Intro to Transfusion and Adverse Transfusion Reactions Flashcards
1
Q
How is blood group defined?
A
Defined by RBC antigens
2
Q
What must match transfusion?
A
Transfusion must be matched to blood type
3
Q
What are the two major blood groupings?
A
ABO system and Rh sytem
4
Q
What is the most important blood group system?
A
ABO system
5
Q
When do A and B antibodies appear in the blood?
A
4-6 months of age as the gut of the baby become colonized
6
Q
Why does an individual make A and B antibodies?
A
If you have A and B antigen on your RBCs, you will not develop antibodies against that type but they develop because of exposure to bacterial antigens with similar structures drives formations of antibodies agianst the A and B antigens
7
Q
What type of antibody are anti-ABO antibodies?
A
IgM
8
Q
Do A and B antibodies cross the placenta?
A
No, they are IgM and IgM does not cross the placenta
9
Q
If the baby and mom do not have the same ABO blood type, is. It a problem?
A
No, because they do not cross they placenta, A and B are natural occuring, in response to bacterial exposure
10
Q
What are the antigens on the RBC’s for Group A,B, AB, and O blood type?
A
Group A blood has A antigens on RBC, Group B blood type has B antigenes on RBC, Group AB blood type has AB antigens on RBC, Group O blood type has neither A or B antigens on RBC
11
Q
What are the antibodies in the plasma for the Group A, Group B, Group AB, and Group O blood types?
A
Group A blood has B antibodies in the plasma, Group B blood has A antiboides in the plasma, Group AB blood has non atibodies in the plasma, Group O blood has both A and B antiboides in the plasma
12
Q
What makes up A and B antigens?
A
A and B antigens are made up of a combination of 4 sugar molecules
13
Q
What are Rh antigens?
A
more than 50 antigens are part of the Rh system, all are transmembrane proteins
14
Q
What Rh antigen is most clinically relevant?
A
Presence or absence of D antigen is critical
15
Q
Why is the D antigen clinically significant?
A
D antigen is highly immunogenic
16
Q
What does Rh+ blood mean?
A
Has D antigen of Rh system, most common
17
Q
What does Rh- blood mean?
A
Lack D antigen of Rh sytstem
18
Q
When does RH- negative blood develop anti-D antibodies?
A
Only happens when exposed to D+ RBCs, Transfusion when D+ donor to D- recepient, Pregnancy when Mom D- with D+ baby (the mother would develop anti-D antibodies)
19
Q
What type of antibody are anti-D antibodies?
A
IgG, a problem in pregnancy because IgG can cross the placenta
20
Q
What is Newbordn Hemolytic Disease?
A
This occurs when antibodies from the mother cross the placenta and attack the RBCs of the baby
21
Q
What is the classical cause of Newborn Hemolytic Disease?
A
Classicallly caused byt anti-D (anti-Rh) antiboides in the mother attacking babies RBCs
22
Q
In what circumstance can Newborn Hemolytic Disease happen?
A
Can only occure in D- mother with D+ baby because genes inherited from the father
23
Q
How can a mother develop anti-D antibodies?
A
1st pregnancy - the mother exposed to D+ RBCs at delivery, 2nd pregnancy - Anti-D IgG in mother can go to the fetus, if the 2nd baby is also D+, hemolysis will occur in utero
24
Q
What do mild cases of NHD present as?
A
If antibody titer in the mother is low, then mild cases present as hemolytic anemia
25
What do severe cases of NHD result in?
If antibody titer in the mother is high, sever cases result in hydrops fetalis causing massive hemolysis
26
How is Newborn Hemolytic Disease prevented?
Give D negative mother Anti-D immune globulin ("RhoGAM"), blocks/prevents isoimmuniztion
27
What does "RhoGAM" consit of?
IgG antibodies to D antigen
28
How does "RhoGAM" work?
If any D+ RBCs get into the mother from circulation, those antibodies will coat that RBC and that will lead to rapid macrophage clearence of D+ RBCs before immune response can occur
29
When is "RhoGAM' given?
3rd trimester to D- women
30
How are D- mothers screened for anti-D antibodies?
Indirect Coombs Test, this involves taking the Mother's serum and mixing it with D+ RBCs - if there is no agglutination (no clumping) then there are no antibodies to D+ RBCs, if there is agglutination then there are antibodies in serum to D+ RBCs "isoimmunization"
31
What are the three general tests of Transfusion Medicine?
Blood Type Test, Type and Screen, Type and Crossmatch
32
How does blood type testing work?
Take the patients RBC's and mix them with Anti-A, B, D if there is agglutination this indicates presence of antigen
33
If you treat a patients RBCs with Anti-A antibodies, and they agglutinate what kind of blood type are they?
Group A positive, there are A antigens on their RBCs
34
How does the type and screent est work?
Take the recepients serum and mix it with standard RBCs (reagent RBCs contain many RBC antigens) if there is no agglutination then there are no antibodies but agglutination indicates positive antibodies in serum to RBC antigens
35
What happens after an abnormal screen?
Determine which antibody is present, test the patient's serum against large panel of antibodies
36
What do frequent transfusions do?
They increase the likelihood that it will be harder to find a match later on because develop lots of antibodies from previous exposure
37
How does the type and cross match occur?
Take the patient's serum and mix with potential donor RBCs, if there is agglutination this means that there are antibodies in the recepients serum agains the donors RBC antigens
38
What is the final test of prodcut to be transfused?
Type and Cross
39
What are packed RBCs?
RBCs with the plasma removed, usually administered instead of whole blood to minimize volume give to patient
40
What do platelet blood prodcuts contain?
Express ABO and HLA class I antigens, do not express Rh or HLA class II, mismatch less common than with RBCs
41
When is Fresh Frozen Plasma given?
Given to correct deficiency of clotting factors, corrects deficiency of any clotting factor, PT/PTT will normalize after infusion
42
What is Fresh Frozen Plasma (FFP)?
Plasma after removal of RBC, WBC, and platelets frozen for storage, once thawed must be used within 24 hours because clotting factors degrade
43
What is cryoprecipiate?
Precipitate that from when FFP is thawed, contatins lots of fibrinogen, given when there is massive bleeding or rare decreased fibrinogen disorders
44
What is the first thing to do if there is an adverse transfusion reaction?
STOP THE TRANSFUSION
45
What type of reaction is an Acute Hemolytic transfusion reaction?
Type II hypersensitivity reaction
46
What does TRALI show on x-ray?
Chest x-ray shows infilitrates which results from neutrophil activation by blood prodcuts
47
What blood group is the universal plasma donor?
Group AB because it has no anti-ABO antibodies in the the plasma
48
What kind of inheritance does blood type follow?
Codominant inheritance
49
What are indication for RBC transfusion?
Evidence of tissue ischemia, due to decreased O2 transport (determining factors - active bleeding, hypovalemic shock 'bleeding to death', labartory evidence of ischemia such as lactic acidosis, rapid decreas in hemoglobin/hematocrit)
50
What are indications for RBC transfusion in non-emergency setting?
HgB less than 7g/dL (Hct less than 21%), if the patient ahs history of cardiovascular disease than transfusion is necessary when HgB is less than 8 g/dL, in cases of symptomatic anemia (short of breath, cardia ischemia, confusion, fatigued)
51
What increased in hemoglobin does 1 unit of RBCs result in?
1 unit of RBCs will give 1g/dL jump in hemoglobin and hematocrity will rise by 3%
52
What is plasma the major source of?
Source of all coagulation factors, provides fibrinogen
53
What are the indication for a plasma transfusion?
Bleeding with decrease coagulation factors (INR > 1.5-2.0) , plasma exchange for selected conditions
54
Why do platelets have increased risk of bacterial overgrowth?
Platelet rich plasma suspension is stored at room temperature
55
When do you administer a platelet transfusion as prophylactic indication?
Platelet count less than 10K
56
When do you administer a platelet transfusion as prior to invasive procedure (to prevent traumatic bleeding)?
Platelet Count less than 50K
57
When do you administer a platelet transfusion as indicated by active bleeding?
Platelet Count less than 50K
58
When do you administer a platelet transfusion as indicated by intracranial (central nervous system) bleeding or intracocular bleeding?
Platelet Count less than 100K
59
What are qualitative defects that indicated a platelet transfusion?
Antiplatelet drugs, Congenital platelet functional defects, following surgery using cardiopulmonary bypass
60
What are the cold insolubable proteins derived from plasma that percipiated at 1-6C (cryoprecipitate)?
FIBRINOGEN (has attached F13), Von Willebrand factor/F8
61
When is cryoprecipitate used?
Almost exclusively for Fibrinogen deficiency but also for Hemophilia A or Won Willebrand Disease (Step 1 related but don’t really do this in clinical practice)
62
How does agglutination occur?
Antibody acts on antigen corsslinking particles and forming a lattice that results in visible clumping or agglutination
63
How is the strenght of agglutination reaction between antigen and antibody graded?
0 (no agglutination) to 4+
64
What is the front type?
Patients RBCs with Reagent antibodies
65
What is the back type?
Patient plasma/serum and reagent RBCs
66
What is the universal RBC donor?
Type O donors, they don't have A or B antigens on RBC
67
What is Coomb's reagent?
anti-IgG
68
What blood type is the closest thing to universal blood?
O negative RBCs, if you know blood type give that blood type because O- is scarce resource
69
What blood types can Group O donate RBCs to?
Anybody
70
What blood types can Group A donate RBCs to?
Group A's and Group ABs
71
What blood types can Group B donate RBCs to?
Group B's and Group AB's
72
What blood types can Group AB's donate to?
Other Group Abs but can received form all others
73
What is the most common cause of Hemolytic Disease of the Fetus and Newborn (HDFN)?
Most common cause of HDFN: Group O mother with a group A or B baby (Group O mother has higher propencity to make antibodies against other blood types)
74
What is leukocyte reduction?
Using a filter, the majority of WBCs are removed form blood products
75
What are the benefits of leukocyte reduction?
Prevents cytomegalovirus (CMV) transmission and reduces incidence of Febrile non-hemolytic transfusion reactions
76
What is the purpose of irradiating blood prodcuts?
Sole purpose is to prevent transfusion associated graft verus host disease (TA-GVHD)
77
What is transfusion associated graft versus host disease?
Donor T-cells proliferate and attack the host (recepient), mortality is greater than (0%
78
What are the symptoms and labartory findings of TA-GVHD?
Pancytopenia and liver function abnormalities
79
What does irradiation of blood products do?
Kills of lymphocytes
80
What are indication for irradiation of blood products?
Bone marrow transplant, Hematologic malignancies, Premature infants/intrauterine transfusion, donations form family members
81
What temperature are platelets stored and what is their shelf life?>
20-24C for 5 days
82
What is the risk of a transfusion transmission of HIV positive unit?
1 in 2 million
83
What is the risk of a transfusion transmission of Hep C positive unit?
1 in 1.5 million
84
What is the risk of a transfusion transmission of West Nile Virus positive unit?
1 in 350,00 (summer)
85
What is the risk of a transfusion transmission of Hep B positive unit?
1 in 300,000
86
What is there still a risk of viral transmission if donor blood is tested?
Window period - donor is infected but the viral load is too low to detect
87
What is a transfusion reaction?
Any adverse reaction to the transfusion of blood or blood components
88
What percent of transfusions will have an expected transfusion reaction?
~1-3%
89
What are acute febrile transfusion reactions?
Acute Hemolytic Transfusion Reaction (AHTR). Febrile Non-Hemolytic Transfusion Reaction (FNHTR) - benighn fever, Bacterial Contamination (Septic Reaction)
90
What constitutes an acute febrile reaction?
FEVER, a greater than or equal to 1 degree C rise over baseline OR when chills/rigors are present
91
When do acute febrile transfusion reactions occur?
Within 24 hours of transfusion
92
What steps are taken when there is a suspected febrile transfusion reaction?
Double check that the right patient got the right blood, redo patient's ABO Rh type and recheck crossmatch compatibility, visual post-transfusion hemolysis check, direct antiglobulin test (DAT) - are there antibodies bound to the patient's red blood cells?
93
What happens during an acute hemolytic reaction?
Patient's preformed antibodies activate complement and cause intravascular hemolysis of donor RBCs, due to ABO incompatible blood (clerical mistake)
94
What are the classcial signs/symptoms of AHTR?
Fever (with or without chills) - sometimes the only presenting feature, Unexplained microvacular bleeding/DIC, Hypotension/shock, Gross hemoglobinuria, Renal failure, Back/flank pain or pain at infusion site
95
What are the labaratory findings for suspected intravascular hemolysis?
Positive Direct Antiglobulin Test (DAT), Signficanlty decreased Haptoglobin, Increased LDH, Increased indirect bilirubin, postive urine hemoglobin
96
Why are platelets highest frequency offender for Bacterial Contamination (Septic Rxn)?
Room temp storage, Gram postive bacteria most common
97
Which transfusion carries greater risk or Septic Rxn is more common in transfusion?
Platelet Transfusion (Gram +), RBC Transfusion (much more rare and severe - Gram -)
98
What is the clinical presentation for septic transfusion reaction?
Fever - high (often greater than 2C increase), rigors/chills, Prominent hypotension, Tachycardia, Nausea/vommitting, Shortness of breath, DIC - Symptoms usually occur very sooon (1st 15 minutes)
99
What are labartory features of Septic Reaction?
Postive bacterial culture (in remainder of blood prodcut), Negative DAT (-), Fever that does not respond to anti-pyretics, Lab evidence of DIC
100
What is the most common febrile reaction?
Febrile Non-Hemolytic Transfusion Reaction (FNHTR)
101
What is the proposed mechanism of FNHTR?
Accumulated cytokines in product (especially IL-1 generated by WBCs during storage)
102
What is the clinical presentation of FNHTR?
Fever greater than 1 degree C during or soon after transfusion, +/- chills or sensation of feeling cold, symptoms often appear towards the end of the transfusion
103
What are acute dyspenic transfusion reactions?
TRALI, TACO, Anaphylaxis
104
What does dyspneic mean?
Difficulty breathing, often associated with lung or heart disease and resulting in shortness of breath
105
How are mild allergic reactions to transfusion treated?
Cutaneous symptoms (hives) only - treat with diphenhydramine
106
What are the symptoms of anaphylaxis?
Hypotension, dyspnea, stridor, wheezing, and GI symptoms, cardiovascular collapse
107
When does anaphylaxis happen during transfusion?
Reaction usually begins after 1-45 minutes of transfusion of any blood product
108
What population is commonly affected by anaphylaxis due to blood transfusion?
Anti-IgA in IgA deficient patient (most common primary immunodeficiency), most common - patient has preformed antibodies to donor serum proteins (e.g. peanut or shellfish allergy)
109
What causes Transfusion Associated Circulatory Overload (TACO)?
Caused by a rapid and/or massive infusion of blood prodcuts results in acute pulmonary edema (induced congestive heart failure)
110
When and how does TACO present?
Within 6 hours of transfusion, dyspenea, cough, tachycardia, hypotension, crackles in lung bases, elevated CVP/pulmonary artery wedge pressure, severe headache
111
What pateints are at risk for TACO?
Elderly, small children, liver/renal failure, positive fluid balance, severe compensated anemia
112
What is the leading cause of transfusion related mortality?
TRALI (Transfusion Related Acute Injury) - Mortality 6-10%
113
What is TRALI?
New acute injury that occurs within 6 hours of transfusion, transfusion of plasma containing products are the most implicated
114
How does TRALI present?
Within 6 hours of transfusion (most within 1 hr), hypotension, dyspnea/cyanosis, frothy fluid form E.T. tube, bilateral "white out" on CXR, mechanical ventilation needed to support oxygenation
115
How are delayed transfusion reactions defined?
Symptoms appear more than 24 hours after transfusion
116
When does delayed hemolytic transfusion reaction happen?
Reaction that occurs after 24 hours and usually less than 28 dyas after transfusion
117
What do lab tests reveal for DHTR?
Labs reveal an inadequate rise in hemoglobin or rapid fall of Hgb without other explanation (decreased haptoglobin and increased LDH an indirect bilirubin)
118
How is DHTR managed?
Symptomatic treatment may be helpful (antipyretics), renal failur can occur in this setting, hydrating patients as a prophylactic measures should be employed with close monitoring of renal output, critical to avoid future transfusions containing the implicated RBC antigen
119
What causes post transfusion purpura (PTP)?
Alloantibodies directed agains HPA-A1 antigen detected after development of thrombocytopenia
120
How is post tranfusion prupura detected?
Post transfusion there is a sudden decrease in platelets to less than 20% of pre-transfusion count and patient has no other condition to explain thrombocytopenia
121
When does post transfusion purpura occur?
Occurs 5-12 days post transfusion, women are morel likey to develop PTP then men
122
How is post transfusion purpura managed?
Intravenous immunoglobulin, steriods, do not transfuse additional random donor platelets, use HPA-A1 negative platelets
123
What are the causes of TA-GVHD?
Immunodeficiency or partial HLA match
124
When does TA-GVHD occur?
Onset 4-30 days
125
What are the laboratory findings for TA-GVHD?
Pancytopenia and liver function abnormalities
