blood bank fundamentals 1 immunohematology building blocks

Blood Bank Fundamentals 1

Immunohematology

Building Blocks

October 2021

Program Director: Jayanna Slayten, MS, MT(ASCP)SBBcmSupervisor, Indiana University Health Blood BankAnd Adjunct Faculty, University of Texas Medical Branch SBB Program

Faculty Disclosure

• None

2

In compliance with ACCME policy,

AABB requires the following

disclosures to the session audience

Objectives• Explain the American Society of Clinical Pathologist (ASCP) SBB and BB

exam requirements

• Review and explain the topics outlined on the ASCP BB/SBB Exam Content

Outline

• Define and relate pertinent information from the ASCP Content Outline that

will be on these exams to aid in preparing for the BB or SBB exam.

• Discover helpful hints for studying for and taking these exams.

• Apply knowledge for interactive question and answer polling session.

3

Blood Bank Fundamentals 2021

Session 1 Session 2 Session 3 Session 4

Blood Bank Fundamentals 1: Immunohematology Building Blocks

Blood Bank Fundamentals 2: Immunohematology Methods and Blood Groups

Blood Bank Fundamentals 3: Transfusion Medicine Physiology and Pathophysiology

Blood Bank Fundamentals 4: Donor Collection, Blood Products, Laboratory Management and Blood Bank Quality

4

Session 1 Speakers

• Diana Riddle, MS,

MLS(ASCP)CMSBBCM

– University of Texas

Medical Branch

– Galveston, TX

• Kathy Haddaway,

MLS(ASCP)CM SBB

(ASCP)CM

– The Johns

Hopkins

Hospital

– Baltimore, MD

5

• LeeAnn Walker,

MEd, MT(ASCP)SBB

– Associate

Professor,

Program Director

– UTMB

SBB/MSTM

Programs

– Galveston, Texas

6

Exam Requirements,

Competencies and Content OutlineRequirements, Competencies , Content

Diana Riddle, MS, MLS(ASCP)CMSBBCM

University of Texas Medical Branch

Galveston, TX

ASCP Website Information• Click on: Board of Certification / U. S. Procedures for Certification

Exam

– 38-page booklet – very helpful

• Eligibility assistant

• Scheduling exam / Studying for exam

– Exam content guidelines

– Reading list

– Exam information

• Exam day

• Results and certificate

• US Military

7https://www.ascp.org/content/board-of-certification

http://www.ascp.org/content/board-of-certification

Application Information

• Complete and submit application online via credit card

• $240 for BB (Non-refundable)

• $290 for SBB (Non-refundable)

• All correspondence from BOC via email (keep email address current)

• Obtain all necessary documentation before applying

8

https://www.ascp.org/content/board-of-certification


Documents Required

Academic education

– Official transcript verifying date of degree

– Evaluation of foreign transcripts

Experience documentation

Accredited program info

– Program director, beginning/ending date, school

number



Application Processing• Application processed within 45 business days of

receipt

• Review of documents may take up to 6 weeks

• Admission letter emailed with instructions for

scheduling exam within 3 months

• All exams administered by computer at Pearson

Professional Centers (List of locations click on

Schedule Exam Date / Find a Test Center)• https://home.pearsonvue.com/coronavirus-update


https://home.pearsonvue.com/coronavirus-update


SBB Exam RequirementsRoute 1

– Bachelor’s degree with required courses

– Successful completion of CAAHEP-accredited SBB program within last 5 years

Route 2– MT/MLS(ASCP) or BB(ASCP)

– Bachelor’s degree

– 3 years FT BB experience within last 6 years after degree

– Must be attained with pathologist oversight in accredited lab (AABB, CAP, COLA, DNV, TJC, JCI, or under ISO 15189)



SBB Exam Requirements

Route 3

– Master’s or doctorate degree

– 3 years FT BB experience in accredited lab within last

6 years after degree

Route 4

– Doctorate degree

– 2 years of post-doctoral fellowship in blood banking

within last 5 years



SBB Exam Requirements

Route 5– MT/MLS(ASCP) or BB(ASCP)

– Bachelor’s degree

– 3 years FT experience as an academic educator in clinical blood banking within last 6 years

Route 6– Masters or Doctorate degree

– 3 years FT experience as an academic educator in clinical blood banking within last 6 years



BB Exam Requirements

Route 1– MT/MLS(ASCP) and Bachelor’s degree

Route 2– Bachelor’s degree in appropriate field with required

courses

– 1-year full-time BB experience within last 5 years

– Must be attained with pathologist oversight in accredited lab




Route 3– Bachelor’s degree in appropriate field with required

courses

– NAACLS Medical Laboratory Scientist Blood Banking Program within last 5 years

Route 4– Master’s or Doctorate degree

– 6 months FT BB experience in accredited lab within last 5 years after degree




Route 5

– Baccalaureate or post baccalaureate degree in

Medical Lab Science or other appropriate degree

– NAACLS Medical Laboratory Scientist Program

within last 5 years



Experience Required

Serologic Testing– ABO and Rh Typing

– Antibody detection and identification

– Crossmatching

– Direct antiglobulin tests

– Tests for other blood group antigens


Routine Problem Solving• Transfusion reactions• Immune hemolytic

anemias• Hemolytic disease of the

fetus and newborn (HDFN)

• Rh immune globulin evaluation

• Indications for transfusion


Experience Required (Cont.)

Quality Control / QA

– Reagents

– Equipment

Laboratory Operations

18

https://www.ascp.org/content/board-of-certification

Donor Collection, Processing, and Testing

• Donor selection, preparation and collection

• Processing and donor testing

• Component preparation for storage and administration


Certification Level Competencies

• Knowledge of Advanced Principles

• Technical Skills

• Problem Solving and Analytical Decision Making

• Communication

• Teaching and Training Responsibilities

• Supervision and Management



Competencies (Questions)

Theoretical - measure skills to:– Apply knowledge

– Calculate results

– Correlate results to disease states

Procedural - measure skills to:– Perform lab techniques

– Evaluate lab data

– Follow QA protocols



Competencies (Examples)

Knowledge of Advanced Principles– Ex: Know the underlying principles of lab testing,

validity of results, causes of discrepant results

Technical Skills– Ex: Know the immunohematology lab procedures

(Methods section flash drive at the back of Technical Manual)

– Ex: Test will measure your understanding of quality assurance and ability to monitor QC programs




Problem Solving and Analytical Decision Making

– Ex: Exam may assess your ability to develop and implement plans to correct and prevent problems

Communication– Ex: Exam may assess your ability to communicate lab

data and factors which can influence test results

– Ex: Exam may test your ability to communicate lab policies and operations




Teaching and Training Responsibilities– Ex: Exam may assess your ability to incorporate

principles of educational methodology in the instruction of lab personnel and other health care providers

Supervision and Management– Ex: Exam may assess your ability to give direction

and guidance to technical and support personnel



Exam Category Percentages

Subtest BB (%) SBB (%)

Blood Products 15-20 10-15

Blood Group Systems 15-20 15-20

Immunology and Physiology 10-20 15-25

Laboratory Operations 5-10 10-15

Serologic and Molecular Testing 20-25 20-25

Transfusion Practice 15-20 15-20



Subtest Descriptions

Subtest Description

Blood Products Donors, processing, storage, blood components, blood component quality control

Blood Group Systems Genetics, biochemistry/antigens, role of blood groups in transfusion

Immunology and Physiology Immunology, physiology, and pathophysiology

Lab Operations Quality assessment/troubleshooting, safety, laboratory mathematics, instrumentation, laboratory administration (SBB only)

Serologic and Molecular Testing

Routine tests, reagents, applications of special tests & reagents, leukocyte/platelet testing, QA

Transfusion Practice Indications for transfusion, component therapy, adverse effects of transfusion, apheresis and extracorporeal circulation, blood administration and patient blood management



26

Immunology,

Complement and Genetics

Kathy Haddaway, MLS(ASCP)CM SBB (ASCP)CM

The Johns Hopkins Hospital

Baltimore, MD

Immunology• Self vs. Non-self vs. Abnormal self

• Types of immune responses

– Innate (nonspecific, present at birth, immediate action)

• Physical barriers (skin, cilia, cough & sneeze reflex, mucus membranes)

• Biochemical barriers (mucus, saliva, tears, sweat, pH)

• Cellular (Phagocytic cells)

• Humoral (complement, cytokines)

• Inflammation (edema, vasodilation, cell migration)

– Adaptive/Acquired (specific, memory, primary vs. secondary)• Cellular (lymphocytes & APCs)

• Humoral (antibodies)

Harmening, D.M. (2012). Modern Blood Banking and Transfusion Practices (6th ed.). Philadelphia: F.A. Davis Company. Chapter 3 27

Immunology• Organs of the Immune System

– Primary (Thymus & Bone Marrow)

• Site of differentiation & maturation of T cells & B cells

– Secondary (Lymph nodes, Spleen, MALT)

• Site of cell function

• Cells of the Immune System

– Hematopoietic Stem Cells (CD34) → self-renewal & differentiation

– T Helper Cells (CD4) → MHC II → stimulate B & cytotoxic T cells

– T Cytotoxic Cells (CD8) → MHC I → destroy tumor & infected cells

– B cells (CD20) → Plasma cell → Make antibodies

– NK cells (CD56) → Lyse tumor & virally infected cells

– APCs (Monocytes, Macrophages, Dendritic cells…) → Phagocytize

Harmening, D.M. (2012). Modern Blood Banking and Transfusion Practices (6th ed.). Philadelphia: F.A. Davis Company. Chapter 3 28

Immunology

Harmening, D.M. (2012). Modern Blood Banking and Transfusion Practices (6th ed.). Philadelphia: F.A. Davis Company. Chapter 3

• Antigen Characteristics that affect immune response

– Size (larger) & Density (more dense)

– Charge

– Accessibility (ability of immune system to see it)

– Solubility (More soluble)

– Digestibility

– Degree of Foreignness• Chemical composition

• Complexity

• Conformation

• Relative Immunogenicity:

– D > K > c > E > k > e > Fya < C < Jka < S < Jkb < s

29

Immunology

Fung, M.K. et al. (Eds.). (2017). Technical Manual (19th ed.). Bethesda, MD: AABB Publications. Chapter 8

• Antibody (Immunoglobulins) Characteristics

– Two Heavy chains & two light chains

– Variable (Idiotype), Constant (Allotype) & Hinge region

– Fc domain & 2 Fab domain (papain)

Isotype IgM IgG IgA IgE IgD

Structure Pentamer MonomerMonomer or

DimerMonomer Monomer

Activate

Complement

Yes,

1 IgM

Yes,

2 IgG

Alternative

pathwayNo No

Cross Placenta NoYes,

IgG2 weaklyNo No No

Subclasses No Yes, 1-4 Yes, 1-2 No No

30

Immunology

Muylle, L. (1995). The role of cytokines in blood transfusion reactions. Blood reviews,9, 77-83.

• Cytokines Types:

• Lymphokines – made by lymphocytes

• Monokines – made by monocytes & macrophages

• Chemokines – increase motility and migration of WBCs

• Interleukins – made by WBCs to act on other WBCs

– Effect:• Autocrine – affects itself

• Paracrine – affects cells in close proximity

• Endocrine – affects systemic activity

– Function:• Growth factor – G-CSF, GM-CSF, M-CSF

• HTR – IL-1, IL-6, IL-8, TNF-α, MCP-1

• FNHTR – IL-1, IL-6, IL-8, TNF-α

31

Immunology

Stevens, C.D. and Miller, L.E. (2017). Clinical Immunology and Serology: A Laboratory Perspective (4th ed.). Philadelphia: F.A. Davis Company. Chapter 14

• Hypersensitivity

– Type I – Allergic

• IgE causes mast cells to release histamine

• Rash, urticaria, anaphylaxis

– Type II – Cytotoxic

• Ag-Ab mediated

• HDFN, Autoimmune disease

– Type III – Immune Complex

• Soluble Ag-Ab complexes

• Drug Induced hemolytic anemia

– Type IV – Cell Mediated

• Antigen stimulates specific T cell mediated cellular damage

• GVHD, Poison Ivy, Allograft rejection

32

Immunology

Stevens, C.D. and Miller, L.E. (2017). Clinical Immunology and Serology: A Laboratory Perspective (4th ed.). Philadelphia: F.A. Davis Company. Chapter 15 & 19

• Immune-mediated diseases

– Immunodeficiency diseases

• Recurrent infections, risk of TA-GVHD

– Autoimmune diseases

• Antibodies form to self, positive DATs

– Gammopathies

• Abnormal production of Ig, Rouleaux

– HDFN• Maternal antibody destruction of fetal RBC’s

• Immunotherapies

– IVIg, RhIg, Monoclonal antibody therapy

• Serologic test interference

33

Complement

Stevens, C.D. and Miller, L.E. (2017). Clinical Immunology and Serology: A Laboratory Perspective (4th ed.). Philadelphia: F.A. Davis Company. Chapter 14

• Role:– Lysis of cells, bacteria, and enveloped viruses

– Opsonization of foreign material to enhance phagocytosis

– Generation of minor proteins that mediate inflammation

• Pathways:– Classical – activated by 1 IgM or 2 IgG

– Alternative – activated by cell walls (bacteria, viruses, etc)

– Lectin – activated by mannose binding lectin on microbial cell walls

• Control of complement activation– Decay Accelerating Factor (DAF) – Cromer blood group

– Complement receptor 1 (CR1)

• Deficiencies of complement components– PNH, SLE, RA

34

Blood Group Genetics

Kathy Haddaway, MLS(ASCP)CM SBB (ASCP)CM

The Johns Hopkins Hospital

Baltimore, MD

35

Mendel’s Principles• Random Segregation

– Distinct units (genes) inherited

– One from each parent

– Random

• Independent Assortment

– Genes inherited independently if carried on different chromosomes

– Combinations of genes are not dependent on other genes (Exception: linkage)

• Linkage Disequilibrium

– Genes on closely linked loci are inherited together as a haplotype

Fung, M.K. et al. (Eds.). (2017). Technical Manual (19th ed.). Bethesda, MD: AABB Publications. Chapter 9 36

Definitions• Allele/ Locus/ Antithetical

• Cis/Trans

• Lyonization

• Genotype/Phenotype

• Dominant/Recessive

• Dosage

• Haplotype

• Homozygous/Heterozygous/Hemizygous

• Suppressor Gene


• Allele

– JK*01 or JK*A

– N demotes null (RHD*01N.01 – D negative)

• Genotype/haplotype

– JK*01/JK*01 or JK*A/JK*A

• Phenotype

– JK:1,-2 (traditionally Jk(a+b-)

• Antigen

– Jk1 or 0009001 or 9.1 (traditionally Jka)

ISBT Terminology


Pedigree Analysis - Genetic Symbols• See Technical Manual...

Not affected Affected Heterozygote/

Carrier

Female

Male

X-linked

recessive


Pedigree Analysis - Genetic Symbols• See Technical Manual...

40

Mating

Consanguineous Mating

Monozygotic Twins

Dizygotic Twins

Proband


Autosomal Dominant

41Fung, M.K. et al. (Eds.). (2017). Technical Manual (19th ed.). Bethesda, MD: AABB Publications. Chapter 9

• Trait appears in every generation (no skipping)• Trait is transmitted by an affected person to half

his children• Unaffected persons do NOT transmit the trait to

their children• Equally likely in both males and females

Autosomal Recessive


• Trait appears in siblings, not in their parents or offspring (not in every generation)

• One-fourth of sibs of propositus are affected

• Parents of affected child may be consanguineous

• Equally likely in both males and females

Sex-Linked Dominant


• Affected Males (XY) transmit the trait to ALLdaughters and to NO sons

• Affected Females (heterozygous XX) transmit to half of their children of either sex

• Homozygous females (XX) transmit to ALL of their children

• Distinguished from autosomal dominant only by offspring of affected males

Sex-Linked Recessive


• Incidence of trait is much higher in males than females

• Trait passed from affected man through all daughters to half of their sons

• Trait is never transmitted directly from father to son

• Trait may be transmitted through a series of female carriers

Y-Linked


• Resembles X-linked• Trait is transmitted only from father to son,

never to daughter• ALL sons will be affected

Blood Group Chromosomes

46

Chromosome Blood Group

1 Rh, Duffy, Scianna, Cromer, Knops, Vel

2 Gerbich, Lan

3 Globoside

4 MNS, JR

6 Chido/Rodgers, I, RHAG, HLA, Augustine

7 Kell, Yt, Colton

9 ABO, Gill, FORS

11 Indian, Raph, CD59

12 Dombrock

15 JMH

17 Diego

18 Kidd

19 Lutheran, Lewis, LW, H, Ok,

22 P1Pk

X Xg, Kx


Population Genetics• Gene and phenotype frequencies are based on

probability

• To determine the frequency of any two (or more) unrelated traits, simply multiply the frequencies of each trait.

47

Populationsample

f = 2%So, f = 2%

Jorde, L.B., Carey, J.C., Bamshad, M.J., & White, R.L. Medical Genetics, 4th ed. St. Louis, MO: Mosby, 2009. Chapter 3

Population Genetics• Gene frequency changes:

– Selection - One gene makes organism more efficient in reproduction, gene

increases in frequency

• Sickle Cell Disease

– Genetic drift – random change in gene frequency by chance, seen more in small

populations

• Ellis–van Creveld syndrome in PA Amish

– Migration/Gene flow – movement of population and breeding with other

populations

– Mutation – change in genetic material

– Meiotic drive – more genes for one allele produced during meiosis

48Jorde, L.B., Carey, J.C., Bamshad, M.J., & White, R.L. Medical Genetics, 4th ed. St. Louis, MO: Mosby, 2009. Chapter 3

Population Genetics

• Hardy/Weinberg Equation

• Basic Formula: (a + b)2

– Two heterozygous parents: (Aa x Aa)

– Offspring: 1 AA + 2 Aa + 1aa

Mom Aa

AA Aa Dad Aa Aa aa

49

Hardy-Weinberg Equation

• Gene Frequencies

p and q (2 allele)

p, q, and r (3 allele)

• Phenotype – 2 allelep2 and q2 (Homozygous)

2pq (Heterozygous)

– 3 allelep2 , q2, r2 (Homozygous)

2pq, 2pr, 2qr (Heterozygous)


Mom Aa

AA Aa Dad Aa Aa aa


• Generalized equation:– (p + q)2 = p2 + 2pq + q2 = 1

– For 2 alleles (gene frequencies): • p + q = 1 or q = 1 - p

– Expanded (phenotype frequencies): • p2 + 2p(1 - p) + (1 - p)2 = 1


Assumption for Hardy-Weinberg Equation

• Individuals of each genotype must be as reproductively

fit as individuals of any other genotype (no infertility or

mortality)

• Population must have large number of individuals

• Random mating must occur

• No mutations

• No migration

52Harmening, D.M. Modern Blood Banking and Transfusion Practices, 6th ed. Philadelphia: F.A. Davis Company, 2012. Chapter 2

• In a given population, 84% of individuals are D positive (D) and 16% are D negative (d)– Phenotype expression:

• DD = p2

• Dd = 2pq

• dd = q2 = 0.16 D negative = 16%

• p2 + 2pq + q2 = 1

– Allele frequency:• p + q = 1

• q = square root of q2

– Square root of 0.16 = 0.4

• p + q = p + 0.4 = 1

– p = 1 – 0.4 = 0.6

53


Therefore:DD = p2 = (0.6)2 = 0.36Dd = 2pq = (2)(0.6)(0.4) =0.48dd = q2 = (0.4)2 = 0.16

1.00

D positive = 84%

54

The Math of the Blood Bank

LeeAnn Walker, MEd, MT(ASCP)SBB

Associate Professor, Program Director

UTMB SBB/MSTM Programs

Galveston, Texas

Formulas…and why we use them…

• Making reagents

• Validating instruments or methods

• FTEs and staffing / cost analysis

• Predicting # of units to screen for antibody

patients

• Blood product QC

• Calculating:

– total blood/plasma volume

– product dosage

– transfusion effectiveness

– special donors

• Scientific Notation (x 106)

– Add, subtract, multiply, & divide

• Conversion Factors

– Weight:

• 1 lb = 0.45 kg

• 1 kg = 2.2 lbs

– Length:

• 1 in = 2.54 cm

• 1 cm = 0.39 in

– Volume:

• 1 qt = 0.95 L

• 1 L = 1.06 qt

• Remember the units!

There’s a LOT of math in our blood bank world!

Doucette, L. J. Mathematics for the Clinical Laboratory, 3rd ed. Philadelphia: W.B. Saunders Company, 2016.

Formulas…and why we use them

• Reagent Preparation

– Prepare & modify solutions

• % Weight/Volume (w/v) - Grams of solute in 100 mL of solution

• % Weight/Weight (w/w) - Grams of solute in 100 grams of solution

• % Volume/Volume (v/v) - Milliliters of solute in 100 mL of solution

– Adjusting concentration• Set up a ratio – V1 x C1 = V2 x C2

– Serial or compound dilutions

• Multiply individual dilutions Technical Manual: Method 1-4Technical Manual: Method 1-5, 1-6, 1-7

• Basic measures of central tendency – LOTS of uses!

– Mean – arithmetic average –

– Median – middle value of a group of data

– Mode – value that occurs most frequently

– Range – difference between the highest and lowest value in

the data set.

– Midrange – Add highest + lowest ÷ 2

– Standard Deviation – square root of the variance


Given the following set of hemoglobin values, determine the

mean, median, mode, range and midrange. All values are g/dL.

10.2

10.5

10.6

12.2

12.8

12.8

13.1

13.2

14.1

• First thing to do is to total the values.

– Number of values = 9

– Total of values = 109.5

– Determine mean = 12.2

• Then put the values in numerical order.

– Determine median, mode, range and mid-range.

13.2

12.8

10.2

10.6

13.1

12.8

12.2

14.1

10.5

Given the following set of hemoglobin values, determine the

mean, median, mode, range and midrange. All values are g/dL.

13.2

12.8

10.2

10.6

13.1

12.8

12.2

14.1

10.5

10.2

10.5

10.6

12.2

12.8

12.8

13.1

13.2

14.1

• Total of values = 109.5

• Mean = 109.5 / 9 = 12.2

• Median (# in the middle) = 12.8

• Mode (# that occurs most often) = 12.8

• Range (highest – lowest) = 14.1 – 10.2

= 3.9

• Mid-range [(highest + lowest)/2] =

– 14.1 + 10.2 = 24.3 / 2 = 12.15 or 12.2


• Sensitivity & Specificity

– Frequently used in research and validation procedures.

– Sensitivity looks at True Positives (TP): TP / (TP + FN)

– Specificity looks at True Negatives (TN): TN / (TN + FP)

– An acceptable sensitivity & specificity will be determined

by the test or by the laboratory requirements.

• Positive Predictive Value (PPV): TP / (TP + FP)

• Negative Predictive Value (NPV): TN / (TN + FN)

• Calculating FTEs and staffing

– Need to know workload and productive hours

• 2080 paid hours / yr (52 weeks x 40 hrs)

• Exclude PTO/holidays

• 75% productivity assumption unless given otherwise– 45 min/hr

• Cost analysis

– Evaluating methods and instruments

– Include salary cost if applicable


Formulas…and why we use them…

• Genetics…

– Hardy-Weinberg

• Determining gene and phenotype frequencies in a population.

– Calculating units for screening

• Remember that you might be given antigen frequencies.

• If not specified, you may also need to include ABO

compatibility in calculations.

• Use Caucasian or general frequencies unless question

specifies otherwise.

Formulas…and why we use them…• Blood product manipulations

– Factor VIII or fibrinogen yield in Cryo

– Platelet yield – whole blood or apheresis

– Extracorporeal volume on apheresis donor or patient

– Adjusting hematocrit

• Product dosage

• Product effectiveness

• Half-Life

– FVIII – approximately 8-12 hrs

– IgG – 23-25 days

• RhIg and exchange transfusions

Lab Math – Blood Volume• To determine Total Blood Volume, Plasma Volume or Red Cell Volume:

Technical Manual: Appendix 5

Premature Term Infant Adult Male Adult Female

Total Blood Volume (mL/kg)

108 87 66 60

If hematocrit is known, calculate PV or RCV.Example: 175 lb. male with hct 44% ( HCT is % of RC, so % of plasma is 1 - hct).

• Convert lb to kg: 175 lb / 2.2 = 79.5 kg• Multiply kg by TBV/kg: 79.5 kg x 66 mL/kg = 5250 mL TBV• For RCV, multiple TBV by hct: 5250 mL x 0.44 = 2310 mL red cells• For PV, multiply TBV by % of plasma: 5250 mL x 0.56 = 2940 mL plasma

Lab Math – Product Dosing• RBCs

– RBCs decrease at a rate of ~1% of per day

– One unit of RBCs increase Hgb by 1 g/dl & Hct by 3%

– 1ml of RBCs = 1 mg of iron

• Plasma

– One unit of plasma increases coag factors by ~10%

• Platelets

– One WB derived plt increases 5,000-10,000/μl in an adult

– One apheresis plt increases 50,000-60,000/μl in an adult

– One WB derived plt increases 75,000-100,000/μl in a term infant

65

Harmening, D.M. Modern Blood Banking and Transfusion Practices, 7th ed. Philadelphia: F.A. Davis Company, 2019. Chapter 16

Lab Math – Product Dosing (Cryo)

For FVIII dosing:

1. Determine desired increment of

FVIII (IU/ml)

– (desired FVIII – initial FVIII)

2. Desired FVIII (IU)

– PV (mL) x desired increment

FVIII (IU/ml)

3. FVIII in Cryo

– Assume 80 IU FVIII per bag of

cryo

4. Desired FVIII (IU)/80 IU = # of bags

For Fibrinogen dosing:

1. Determine desired increment of

Fibrinogen (mg/mL)

– (desired fibrinogen – initial fibrinogen)

2. Desired Fibrinogen (mg/mL)

– PV (mL) x desired increment

Fibrinogen (mg/mL)

3. Fibrinogen in Cryo

– Assume 150 mg per bag of cryo

4. Desired Fibrinogen (mg)/ 150 mg = # of

bags

66

For either FVIII or for Fibrinogen: Determine plasma volume

A severe hemophiliac is scheduled for surgery tomorrow. His physician wants to increase his Factor VIII level to 75% before the procedure. His hematocrit is 40% and his plasma volume is 3000 mL. How many bags of cryoprecipitate should be given?

• Number of bags =

– PV x [Desired activity (%) – Current activity (%)] x PV / 80

• Severe hemophiliac has 0 FVIII activity.

• 3000 mL x (0.75 - 0) = 2250 IU FVIII

• 2250 IU / 80 IU = 28 bags of cryo

Lab Math – Product Yield• Percent Yield (Cryo or WB platelets) =

amount x mL final product x 100%

amount x mL original product

Lab Math – Neonatal exchange transfusion• Volume of WB to transfuse (mL) =

• Infant’s TBV (mL) x # of exchanges = Total vol (mL) for exchange

• Volume (wt) of RBC unit x Hct = RBC volume available

• RBC volume ÷ desired Hct = Total WB volume from that unit• Total WB volume from unit – volume of existing unit = volume of

plasma to add

NOTE: Specific Gravity of RBC is ~1.06, so to determine mL:

• Wt (g) / 1.06 = Vol (mL)

Lab Math – Calculating Fetal Maternal

Hemorrhage & RhIG• Volume Fetal maternal hemorrhage (ml)

# fetal cells counted x maternal blood volume x maternal blood volume

# maternal cells counted

Or

% fetal cells x 50 (50 = factor for average maternal blood volume of 5000 mL)

• RhIg dose (vials) =Volume FMH whole blood (ml) / 30 ml/vial

Volume FMH pRBC (ml) / 15 ml/vial

– Round up or down + 1 vial

Lab Math - Additional Formulas:

• Relative Centrifugal Force 11.17(r)(n/1000)2

• r = radius in cm

• n = rotor speed in rpm

• Relative Risk (RR) HLA disease association(% patients with HLA antigen) x (% controls without HLA antigen)

(% controls with HLA antigen) x (% patients without HLA antigen)

70

Cohn, CS. et al. (Eds.). (2020). Technical Manual, 20th ed. Bethesda, MD: AABB Publications. Chapter 16

Remember the Units!!• Other quick facts…

– Maximum volume of blood to draw from a donor: 10.5 mL/kg

• Or Donor weight (lbs) x 450 mL

110 lbs

– Maximum extracorporeal volume for apheresis: 15% of TBV

– Scientific Notation

• To add or subtract, the exponent must be the same; then

add or subtract the mantissas (the number part).

• To multiply, multiply the mantissas and add the exponents.

• To divide, divide the mantissas and subtract the exponents.

References•Cohn, Claudia, et al, ed. Technical Manual, 20th ed. Bethesda, MD: AABB, 2020.

•Fridey, JL, Kasprisin, CA, Chambers, LA, Rudmann, SV. Numbers for blood bankers. Bethesda, MD: American Association of Blood Banks, 1995.

•Doucette, L. J. Mathematics for the Clinical Laboratory, 2nd ed. Philadelphia: W.B. Saunders Company, 2010.

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Test Your Blood Bank Knowledge

Q and A Session

BB Fundamentals Session 1

BBF1. Q0 How many years

experience are required to sit for the

BB exam?

• 3 years in the last 10 years

• 1 year in the last 5 years

• 3 years in the last 6 years

• No experience required

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BBF.1 Q1: A transfusion reaction was reported for a patient who received a

unit of plasma earlier today. The lab results are as follows:

Symptoms: hives, urticarial, pruritis

Pre-temp: 37.0oC Post temp: 37.2oC

Pre BP: 120/78 Post BP: 115/75

Pre Hgb: 12.0 g/dL Post Hgb: 11.8 g/dL

Urine: clear, yellow; Hgb – negative; 0 RBC’s/hpf

What type of hypersensitivity reaction is this patient experiencing?

a. Type 1

b. Type 2

c. Type 3

d. Type 4

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BBF Q2 Given the pedigree below, what type of inheritance is the trait?

A) Autosomal Dominant, b) Autosomal Recessive, c) X Linked

Dominant, d) X linked recessive

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A. 790

B. 620

C. 520

D. 455

BBF Q3 Male pattern baldness is controlled by a recessive gene (b), while non-baldness is coded by a dominant allele (B). Out of 1000 random men, 380 had a full head of hair. How many would be carriers of the baldness gene?

BBF.1 Q4 A 2.5 lb premature neonate requires an exchange transfusion due to anti-c HDFN. How much reconstituted whole blood is needed for a 2-volume exchange?

A. 240 mL

B. 220 mL

C. 105 mL

D. 95 mL

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Thank You for Participating

Please Continue with us with the next

BB Fundamentals Course

Blood Bank Fundamentals 2: Immunohematology

Methods and Blood Groups