Study Guide- ASCP MLT BOC Examination in Blood Banking (Immunohematology)

Study the table below to assess how far have you learned in Blood Banking or Immunohematology as a preparation for your actual examination for the the American Society of Clinical Pathology (ASCP) Board of Certification.

ASCP MLT BOC Immunohematology
Question	Answer
What stimulates the Primary Immune Response?	First exposure to an antigen
How long is the lag phase for Primary Immune Response?	Days to Months
What type of antibodies are associated with Primary Immune Response?	IgM at first. May switch to IgG after 2-3 weeks (isotype switching)
What is the titer reaction for Primary Immune Response?	Rises slowly. Peaks then declines.
What does "lag phase" mean?	The period of inactivity after exposure to an antigen before the body produces an immune response.
What stimulates the Secondary Immune Response?	Subsequent exposure to antigen
How long is the lag phase for Secondary Immune Response?	Hours
What type of antibodies are associated with Secondary Immune Response?	IgG only
What is the titer reaction for Secondary Immune Response?	Rises faster and higher and stays elevated longer.
What is the structure and number of binding sites of IgG?	Monomer and 2 binding sites
What is the optimum temperature of reactivity for IgG?	37°C
Which antibody (IgG or IgM) reacts in saline?	IgM
Which antibody (IgG or IgM) reacts best by the indirect antiglobulin test (IAT)?	IgG
What is the strength of complement fixation for IgG?	Moderate
Which antibody (IgG or IgM) causes transfusion reactions?	IgG Not usually IgM, except ABO
Which antibody (IgG or IgM) crosses the placenta?	IgG
Which antibody (IgG or IgM) is destroyed by sulfhydral compounds? (dithiothreitol [DTT], 2-mercaptoethanol [2-ME]	IgM
What is the structure and number of binding sites for IgM?	Pentamer and 10 binding sites
Which antibody (IgM or IgG) is naturally occurring and which is Immune?	IgM is naturally occurring IgG is Immune
What is the optimum temperature of reactivity for IgM?	25°C or lower
What is the strength of complement fixation for IgM	Strong
What are the 2 signs of Antigen-Antibody reactions in blood bank testing?	Hemolysis and agglutination
What is the optimum pH for Ag/Ab reactions?	pH 5.5-8.5
What is LISS?	Low Ionic Strength Solution: lowers ionic strength of suspending medium, allowing AG and AB to move closer together. Reduces incubation time to 10 minutes
What is prozone?	Too much antibody, not enough antigen, can cause false-negative
What is 20-30% albumin used for?	Causes agglutination by adjusting zeta potential between RBCs
What is zeta potential?	The difference in charge between the negative charged RBC surface and the cloud of positive ions that surround the RBCs. Reducing zeta potential allows RBCs to move closer together.
What is PEG?	Polythyleneglycol: Increases antibody uptake. Used for the detection and ID of weak IgG antibodies
What are enzymes used for in Blood Bank testing?	Reduces RBC surface charge by cleaving sialic acid molecules. M, N, S, Fya, and Fyb antigens are destroyed. i.e. ficin, blomelin, and papain.
What is AHG?	Antihuman Globulin: Used to agglutinate cells that are sensitized (have antibody or complement attached)
Polyspecific (broad spectrum) AHG	Detects IgG and C3d Used for DAT and in some labs, routine compatibility tests and anitbody detection
Monospecific AHG	anti-IgG only: detects clinically significant antibodies
What is the DAT?	Direct Antiglobilin testing: Detects in-vivo sensitization of RBCs by IgG antibody
What is the preferred specimen for DAT?	EDTA red cells
Which antiglobulin test (DAT or IAT) is incubation required?	IAT: Patient serum or plasma with reagent RBCs or Patient RBCs with reagent antiserum
When is the DAT done? What is it's purpose?	Hemolytic disease of the newborn Transfusion reactions Autoimmune hemolytic anemia Drug induced hemolytic anemia
What is the IAT?	Indirect Antiglobulin Testing: Detects in-vitro sensitization of RBCs by IgG antibody
What is the preferred specimen for IAT?	Serum, plasma, RBCs
When is the IAT done? What is it's purpose?	Antibody screen, Crossmatch, RBC phenotyping, weak D testing
What is the A antigen's precursor and terminal sugar?	H substance and N-acetylgalactosamine
What is the B antigen's precursor and terminal sugar?	H substance and D-galactose
What is the frequency of ABO blood types in whites?	45% O, 40% A, 10% B, 5% AB
What is the frequency of ABO blood types in Blacks?	49% O, 27% A, 20% B, 4% AB
What is the frequency of ABO blood types in Hispanics?	56% O, 28% A, 12% B, 4% AB
What is the frequency of ABO blood types in Asians?	43% O, 27% A, 25% B, 5% AB
What is the genotype of Rh positive blood?	DD or Dd
What is the genotype of Rh negative blood?	dd
What is the frequency of D antigen in Whites and Blacks?	Whites 85% Blacks 93%
R0	Dce
R1	DCe
R2	DcE
Rz	DCE
r	dce
r'	dCe
r"	dcE
ry	dCE
Most common Rh genes in Whites (in descending order)	R1, r, R2, R0,r', r"
Most common Rh genes in Blacks (in descending order)	R0, r, R1, R2, r'
Which blood antigens are uncommon in Whites? (<25>	K, Lea, Lua
Which blood antigens are uncommon in Blacks? (<50>	K, Fya, Fyb, S, Lea, Lua, Lub
Which blood antigens are most common in Whites? (>80%)	k, Fyb, s, U, I, Lub
Which blood antigens are most common in Blacks? (>80%)	k, Jka, s, U, I, P1
I antigen presence	Much in Adult cells Trace in cord
i antigen presence	Trace in Adult cells Much in Cord cells
Naturally occurring antibodies	ABO, Lewis, P1, MN, Lua
Clinically significant Antibodies	ABO, Rh Kell, Duffy, Kidd, SsU
Warm antibodies	Rh, Kell, Duffy, Kidd
Cold antibodies	M, N, P1
Antibodies that usually only react with AHG	Kell, Duffy, Kidd
Which antibody can react in any phase of testing?	Lewis
Detection of antibody enhanced by enzyme treatment of test cells	Rh, Lewis, Kidd, P1
Antibodies not detected with enzyme treatment of test cells	M, N, S, Duffy
Which antibody is enhanced by acidification	M
Which antibodies show dosage?	Rh(not D), MNS, Duffy, Kidd
Which antibodies bind complement?	I, Kidd, Lewis
Which antibodies cause in vitro hemolysis?	ABO, Lewis, Kidd, Vell, and some P1
Which antibodies are labile in vivo and in vitro?	Kidd
What does labile mean?	deteriorates rapidly in storage
antibody that commonly causes anamnestic response	Kidd
Define anamnestic response	delayed transfusion reaction
Which antibody is associated with paroxysmal nocturnal hemoglobinuria?	Anti-P
What is paroxysmal nocturnal hemoglobinuria PNH?	Defect in RBC membrane, makes in more susceptible to hemolysins in an acid environment. Hgb found in urine after periods of sleep.
Which antibody is associated with cold agglutinin disease and Mycoplasma pneumoniae infections	Anti-I
Which antibody is associated with infectious mononucleosis?	Anti-i
Antibody ID Reaction: same strength and in one phase only	Suggestive of single antibody
Antibody ID Reaction: Varying strength	Multiple antibodies, antibody exhibiting dosage, antigens of differing strength
Antibody ID Reaction: in different phases	Combination of warm and cold antibodies, antibody with wide thermal range
Antibody ID Reaction: All cells in AHG, autocontrol negative	Multiple antibodies, antibody with high frequency antigen
Antibody ID Reaction: All cells in AHG, autocontrol positive	Warm autoantibody
Antibody ID Reaction: All cells at 37°C, negative in AHG, autocontrol positive	Rouleaux
How long do you retain patient specimen and unit segment and what temperature do you store it at?	7 days following transfusion at 1-6°C
How many days before a transfusion must the specimen be collected for compatibility testing?	3 days
What is an antiglobulin crossmatch?	Recipient serum and donor RBCs are tested with the IAT. Required when recipient has, or previously had, a clinically significant antibody
What is an abbreviated crossmatch?	Recipient serum and donor RBCs are tested in immediate spin only. Permissible if recipient doesn't have, and has never had, clinically significant antibodies. Test of ABO compatibility.
What is a computer crossmatch?	Computer check of donor ABO and Rh type and recipient ABO and Rh type. Permissible if recipient doesn't have, and has never had, clinically significant antibodies.
What tests are done on newborns for transfusion?	ABO and Rh typing (forward grouping only), Antibody screen,and crossmatch (only need if AB screen is positive)
What conditions must be met if RBCs are being used for reissue?	1-10°C, closure not broken, at least one segment left, unit inspected, records indicate blood has been reissued
Clinical signs of hemolytic (intravasuclar) tx rxn	Fever, chills, shock, renal failure, DIC, Pain in chest, back, or flank
Clinical signs of hemolytic (extravascular) tx rxn	Fever, anemia, mild jaundice 2 or more days after transfusion
Clinical signs of febrile txrxn	Increase of temperature > or = to 1°C within 24 hours of transfusion with no other explanation
Clinical signs of allergic txrxn	Hives
Clinical signs of anaphylactic txrxn	Bronchospasms
Clinical signs of circulatory overload txrxn	Coughing, cyanosis, difficulty breathing
Clinical signs of septicemia txrxn	Fever, cramps, diarrhea, vomiting, muscle pain, DIC, shock, renal failure
Specimens needed for a txrxn investigation	Pre-transfusion blood Post-transfusion blood Post-transfusion urine Segment from unit Blood bag with administration set and attached IV solutions
At what gestational age is RhIG administered?	28 weeks
How long postpartum is RhIG given to Rh negative women with Rh positive baby?	within 72 hours
What is the dose of RhIG given to Rh negative mother with Rh positive baby?	One dose per 15 ml of D positive fetal RBCs.
AABB age requirement for blood donation	At least 17 yrs old
AABB weight requirement for blood donation	At least 110 lbs to donate 525 ml
How often can you donate blood (AABB)?	Every 8 weeks
AABB blood pressure requirement	Systolic < or =180 Diastolic < or =100
AABB pulse requirement	50-100 with no pathological cardiac irregularities
AABB hemoglobin/hematocrit requirement	> or = 12.5 g/dL HGB > or = 38% HCT
AABB body temp requirement	< or = 37.5°C (99.5°F)
3 day blood donor deferral (AABB)	Aspirin containing medications if donor is sole source of plateletss
2 week donor deferral (AABB)	Measles, mumps, polio, or yellow fever vaccines
4 week donor deferral (AABB)	Rubella vaccine
6 week donor deferral(AABB)	Pregnancy
12 months donor deferral (AABB)	Syphilis, Gonorrhea, Animal bite, HBIG, Tattoo, Mucous membrane exposure to blood, Needle stick, Household or sexual contact with individual with hepatitis, sexual contact with individual with HIV, Travel to area endemic with Malaria
3 year donor deferral (AABB)	Malaria, or from an area endemic for malaria
Permanent donor deferral (AABB)	Parenteral drug use, family history of Creutzfeldt-Jakob disease, Treated with growth hormone, Viral hepatitis after 11th bday, Positive HBsAg, Repeatedly reactive anti-HBc, anti-HCV, anti-HTLV, or anti-HIV,Babesiosis, Chagas' disease
Volume of anticoagulant for blood unit collection	63 ml
Volume of blood collected for blood unit	450 +-45 ml
Low volume unit	300-404 ml; label "low volume unit" don't use to prepare platelets or plasma components
When should the volume of anticoagulant be reduced?	When the blood volume is <300 ml="">
Time of collection for blood unit	4-10 minutes, if >15 minutes, blood may not be suitable for preparation of platelets or FFP
Temperature of blood unit	20-24°C for up to 8 hours if components are going to be prepared, otherwise 1-6°C
Acid-citrate-dextrose	ACD anticoagulant shelf life 21 days
Citrate-phosphate-dextrose	CPD Anticoagulant shelf life 21 days High pH preserves 2,3-DPG better. Better O2 delivery.
Citrate-phosphate-dextrose with adenine	CPDA-1 shelf life 35 days Adenine increases adenosine disphosphate ADP
Adsol	AS-1 Additive Shelf life 42 days Provides nutrients for improved viability
Nutricel AS-2	AS-2 Additive Shelf life 35 days Provides nutrients for improved viability
Nutricel AS-3	AS-3 additive shelf life 42 days
Phosphate-inosine-pyruvate-adenine	PIPA rejuvinating solution used to salvage rare or type O units up to 3 days beyond expiration, must then be transfused within 24 hours or frozen
Donor serological testing (AABB or FDA)	ABO, Rh, AB Screen, RPR, HBsAg, Anti-HBc, Anti-HCV, Anti-HIV 1/2, HIV-1-Ag, Anti-HTLV-1 and 2
Autologous donation frequency	every 3 days but not within 72 hours of transfusion
Autologous donation Hgb requirement	not less than 11 g/dL
Temperature and shelf life of RBCs	1-6°C and 35 days in CPDA-1, 42 days in AS-1
Temperature RBCs frozen	40% glycerol: &lt; or = -65°C 20% glycerol: &lt; or = -120°C 1-6°C after glycerolization
Shelf life or RBCs frozen	10 years after phlebotomy, 24 hours after deglycerization
Temperature and shelf life of washed RBCs	1-6°C 24 hours after washing
Temperature and shelf life of Leukocyte reduced RBCs	1-6°C Closed system:10 years Open system: 24 hours
Temperature and shelf life of Rejuvinated RBCs	1-6°C 24 hours after rejuvination if not frozen
Temperature and shelf life of irradiated RBCs	1-6°C Original outdate or 28 days from irradiation, whichever occurs first
Temperature and shelf life of FFP	< or = -18°, After thawing 1-6°C 12 months, After thawing transfuse within 24 hours
Temperature and shelf life of Cryoprecipitate	< or = -18°C, After thawing room temperature 12 months, After thawing transfuse within 6 hours if unit is not entered, within 4 hours in pooled
Temperature and shelf life of platelets	20-24°C 5 days 5 days with agitation
Temperature and shelf life of granulocytes	20-24°C 24 hours
Increased in stored blood	Plasma K+, Plasma NH3, Plasma Hgb, microaggregates
Decreased in stored blood	pH, ATP, 2,3-DPG, Viable RBCs, WBCs, and platelets, Labile coagulation factors
Centrifuge QC	Check RPM and timers quarterly Determine optimum speed and time for procedures upon receipt, after repairs, and semiannually.
Cell washers QC	Check volume of saline and AHG in each tube, verify time and speed of centrifugation periodically
Waterbaths QC	Check temperature daily
Heat blocks QC	Check temperature daily. Periodically check each well.
Refrigerators QC	System to monitor temperature continuously and to record temperature at least every 4 hours. Alarm system with audible signal. Must be 1-6°C
Freezers QC	System to monitor temperature continuously and to record temperature at least every 4 hours. Alarm system with audible signal.
Alarms QC	Check high and low temperatures of activation quarterly
Platelet incubators QC	System to monitor temperature continuously and to record temperature at least every 4 hours. Should be 20-24°C. Check RPM periodically.
Pipettes and droppers QC	Determine average delivery volume. Calculate # of drops that will give 80:1 serum to cell ratio
Antisera QC	Test with positive and negative controls each day of use. Use heterozygous cells for positive controls
Reagent cells QC	Check for hemolysis. Test daily with pos and neg controls
AHG QC	Check anti-IgG activity by testing Rh-positive cells sensitized with anti-D
How long should QC records be kept?	5 years or longer
When are washed RBCs needed?	Anemic patients with paroxysmal nocturnal hemolgobinuria, ABs to IgA, or history of febrile reactions
When are leukocyte reduced RBCs needed?	Anemia with history of febrile reactions
When are irradiated RBCs needed?	Intrauterine transfusions, immunocompromised recipients, recipients of blood from a relative, or bone marrow transplant patients
When is FFP needed?	Deficiency of coagulation factors
When is cryoprecipitate needed?	Hemophilia A, Von Willebrand's disease, hypofibrinogenemia, Factor XIII deficiency
When are platelets needed?	Prevent or stop bleeding in patient with thrombocytopenia or abnormal platelet function.
When are granulocytes needed?	Neutropenia with infection
How long after receiving a donation of blood products are patients deferred for donation?	12 months
CPDA-1 ingredients	Citrate, Dextrose, Adenine, Sodium biphosphate
Citrate purpose in CPDA-1	Prevents coagulation by chelating calcium
Dextrose purpose in CPDA-1	Supports adenosine triphosphate (ATP) generation
Adenine purpose in CPDA-1	Substrate for ATP synthesis
Sodium biphosphate in CPDA-1	Prevents excessive fall in pH during storage
Blood product that must be separated from whole blood and frozen within 8 hours of collection	Fresh Frozen Plasma
How is cryoprecipitate prepared?	By thawing FFP between 1-6°C, removing plasma, and freezing within 1 hour.
RBCs must be frozen in:	glycerol within 6 days of collection
How long after plasmapheresis must a person wait to donate a unit of Whole Blood?	48 hours
Each unit of whole blood will yield approximately how many units of cryoprecipitated AHF?	80 units
90% of all platelet pheresis units tested contain how many platelets per ul?	3.0 x 10"
Terminal sugar for H antigen	L-fucose
Approximate % of original plasma content of Factor VIII recovered in Cryoprecipitated AHF	40-80%
What is the formula to calculate fetomaternal hemorrhage for RhIg?	(fetal cells/number of cells counted)x maternal blood volume
Liley method of predicting the severity of HDN is based on aminiotic fluid:	change in optical density measured at 450 nm