Blood Bank Q1

Blood Components Blood Preservation Intro to blood group ABO NOT donor testing or selection

purpose of blood storage

- maintain viability and stability of component

- inhibit growth of organisms

- prevent clotting of product

- maintain normal hemoglobin function

considerations to accomplish proper storage

- anticoagulant and preservative

- characteristics of plastic bags

- storage temperatures

- shipping and transport temperatures

characteristics of plastic bags

- closed system

- separation into attached bags

- gas permeable to CO2 to maintain pH

- transparent

- flexible

RBC function

carries O2 to tissues and CO2 to lungs

oxygen delivery is affected by

- pH of blood

- hemoglobin structure

- partial pressure of CO2

- temperature

- concentration of 2,3 DPG

oxygen dissociation curve

shift to the right: decreased affinity

shift to the left: increased affinity

2,3 DPG levels

- increased 2,3 DPG has decreased affinity for oxygen

- decreased 2,3 DPG has increased affinity for oxygen

2,3 DPG

- anticoagulant/preservative solutions must maintain RBC viability and storage levels of 2,3 DPG

- levels decrease in stored blood with first 10 days of storage

- requires 24 hours to return to normal

RBC lesion of storage

biological changes that take place in stored blood:

- pH decreases

- ATP decreases

- 2,3 DPG decreases

- Na+ and K+ increase (released as cells die/burst)

- plasma hemoglobin increases (may leak out of cells)

additives to RBC

- improve ATP levels

- saline, dextrose, and adenine

- only FDA approved additives can be added to RBCs (CPD and CP2D)

- must be added within 72 hours of phlebotomy

blood collected in CPD or CP2D

after plasma is removed, it is approved for 21 days in storage at 1-6 C

blood collected in CPDA-1

approved for 35 days storage at 1-6 C

blood collected with AS-1, AS-3, AS-5, AS-7

- contain mannitol, saline, adenine, dextrose

- storage up to 42 days

rejuvenated solutions

- added to RBCs up to 3 days after expiration date

- increases levels of 2,3 DPG and ATP

- incubated for 1 hour with cells

- cells are washed

- infused within 24 hours or frozen

- used only in rare cases

rejuvenated solutions contain

pyruvate, inosine, phosphate, adenine, and glucose

storage requirements

refrigerators, freezers, environmental chambers

- continual monitoring of temperature

- audible alarm signals

- alarm checks on regular basis

- emergency procedure for power failure and alarm activation

- emergency back up system

- thermometers compared with calibrated thermometers at least annually

- separate area for tested, untested, and quarantined products

blood inspection

- hemolysis, clots, or purple, brown, or red plasma

- bacterial contamination

- green hue due to bilirubinemia in older units

main bacteria found in donated blood

Yersinia entercolitica

storage temperature for RBC or whole blood

1-6 C

fridge

storage temp for FFP

storage temp for cryo

temp for RBCs frozen in 40% glycerol

temp for RBCs frozen in 20% glycerol

storage for platelets

20-24 C

incubator

storage for granulocytes

20-24 C

blood group systems

- a group of related antigens on the RBC membrane

- these antigens are glycoproteins produced at the same locus or so close that they do not cross over, or it is very rare

modes of inheritance for blood group systems

- follow principles of independent segregation and independent assortment

- only one member of an allelic pair from each parent is passed to the next generation

- autosomal dominant, autosomal co-dominant traits, or autosomal recessive trait

codominant

equal/independent expression of 2 alleles

amorphic alleles

- rare

- mutation of gene that results in complete loss of function

- does not code for anything

null phenotype

mutation that causes loss of function

high frequency

majority of population has

low frequency

most of the population does NOT have

complications with antibodies

- transfusions

- hemolytic disease of the fetus and newborn

- clinically significant antibodies react at 37 C and/or AHG

IgG

warm antibody

more clinically significant

Hardy Weinberg principle

- gene frequencies tend to remain constant and maintain equilibrium over generations

- allows calculation of genotype frequency from gene frequency

Hardy Weinberq equation

p^2 + 2pq + q^2 = 1

p+q = 1

forward grouping

determination of ABO antigens found on patient red blood cells using reagent antisera

group A blood

A antigen, anti-B antibodies

group B blood

B antigen and anti-A antibodies

group O blood

anti-A and anti-B antibodies

no antigens

group AB blood

A and B antigens, no antibodies

reverse grouping

determination of ABO antibodies found in patient plasma using reagent RBCs

ABO antibodies are generally

- IgM (reacts best at 37C)

- RBC immune form is predominantly IgG

ABO antibodies

- activate complement

- generally present within 3-6 months of life (reverse typing not done

ABO antibody titers with age

- adult level reached at 5-10 years

- levels off through adult life

- begin to decrease in later years

Anti-A,B antibody

- single antibody, IgG

- reacts with both A cells and B cells

anti-A antibodies

react with A1 and A2 RBC antigens

anti A1 antibodies

- reacts only with A1 antigens

- can be made by A2 and A2B phenotypes

- can cause ABO discrepancy

Dolichos biflorus

- has anti-A1 activity

ABO antigens

genes at three separate loci control the occurrence and location of A and B antigens

Hh genes

- H and h alleles

- H allele codes for an enzyme that forms the H antigen onto which A and B cells are build

- h/h is called Oh or Bombay

Se genes

- Se and se alleles

- Se allele codes for an enzyme that allows secretion of H and AB antigens

- se/se is a non-secretor

ABO genes

- A, B, and O alleles

- A and B alleles code for enzymes that add a sugar to H antigens to produce A and B antigens

- O allele does not code a functional enzyme

location of ABO antigens

- presence/absence of ABH antigens on red cell membrane is controlled by H gene

- presence/absence of ABH antigens in secretions is controlled by Se gene

Type 1 H antigen

- glycoproteins in secretions

- Se gene enzyme (FUT2) adds fucose

Type 2 H antigen

- red cell membrane

- H gene enzyme (FUT1) adds fucose

H gene

codes for enzyme (fucosyltransferase) that adds fucose to the terminal sugar of Precursor Substance

H antigen

- foundation upon which A and B antigens are built

- found on RBCs when HH or Hh present (not hh)

A and B genes

code for enzymes that add an immunodominant sugar to the H antigen.

A gene

adds GalNAc

N-acetyl-D galactosamine

B gene

addition of D-galactose

A antigen

found on RBCs with HH or Hh, and A/A, A/O, or A/B genotypes

B antigen

found on RBCs with HH or Hh, and B/B, B/O, or A/B genotypes

amount of H antigen according to blood group

- group O people have RBCs rich in H antigen

- presence of A or B gene decreases the presence of H antigen

O > A2 > B > A2B > A1 > A1B

Bombay phenotype (Oh)

- homozygous hh results in inability to form the H antigen and subsequently A or B antigen

- phenotype has no H, A, or B antigens on RBC membrane, only precursor substance

- also has anti-A, anti-B, and anti-H antibodies

what blood type can be transfused to Bombay phenotypes

other Bombay phenotypes

h/h se/se

ABO antigens in secretions

soluble blood group substances are found in secretions, which is controlled by H and Se genes

secretions

body fluids

- includes plasma, saliva, synovial fluid

blood group substance

soluble antigen found in the secretions but not bound to a membrane such as RBC or epithelial cell

genes necessary for production of ABH antigens in secretions

must have Se gene for ABH to be in secretinos

O/O genotype in secretions

H antigen in secretions

h/h genotype in secretions

- no ABH antigens in secretions

- no antigen on RBC

se/se genotype in secretions

- no ABH antigens in secretions

- RBC has antigen

ABO subgroups

- ABO phenotypes differ in the amount of antigen on RBCs and in saliva

- subgroups are the result of less effective glycosyltransferase enzymes

- A are more common than B

A1 subgroups

- 80% of all group A

- A1 cells have 4-6x the number of antigen sites on RBC surface than A2

- agglutinate with Dolichos biflorus

- seen often in ABO discrepancy

what A subgroup reacts with anti-A

both

subgroup A3

mixed field

subgroup of B

same explanations as A

other subgroups of A

have weaker expression of A antigen

disease association with ABO

- some diseases may alter ABO expression

- leukemia decreases antigen strength

age related expression of ABO

- elderly patients' antibody production is decreased (affects reverse typing)

- newborn antibody production is detectable at 3-6 months

acquired B

- patients with intestinal obstruction or carcinomas of colon/rectum have increased permeability of intestinal wall

- allows bacterial polysaccharides from E coli to enter circulation

- A cells absorb B-like polysaccharide (free floating acetyl group)

acquired B when typing

forwards like an AB but reverses like an A

Group I discrepancy

- missing antibody (most common)

- normal forward reactions

- missing reverse reactions

Group I discrepancies are seen in

- newborns, elderly, BM transplant, immunocompromised patients

- hypogammaglobulinemia

- congenital agammaglobulinemia

how to determine Group I discrepancies

- enhance the reverse typing (RT for 15 minutes and 4C for 15-30)

- run auto control to rule out possible interfering cold agglutinin

chimerism

2 cell populations in one person

artificial chimerism

transfusions or fetomaternal bleed

true chimera

twins have 2 cell population that exists throughout their life

Group II discrepancy

- missing antigen

- subgroups of A or B

- leukemias or lymphomas

Group III discrepancy

- abnormal protein or plasma

- results in rouleaux

- Wharton's jelly (from cord blood, requires washing several times)

- disperse with saline

Group II discrepancies are seen in

- multiple myeloma

- Waldenstrom's macroglobulinemia

- Plasma expanders

Group IV discrepancy

- miscellaneous

- polyagglutination

- unexpected allos

- cold autos

- antibody to acriflavine (yellow dye in anti-B)

- A2 with anti-A1

polyagglutination

- agglutination of RBC by human reagents

- monoclonal

- due to hidden RBC antigens (Tn antigens)

- bacterial infection exposes Tn antigens (Tn activation)

- may cause acquired A-like antigen

cold autos

- forward and reverse are both positive

- wash cells in warm saline

- auto absorb the plasma

- also seen in WAIHA

A2 with anti-A1

- forwards like an A, reverses like an O

- use A1 lectin, will be negative if subgroup of A

- use A2 cells, should be negative if A2

blood components

refers to those fractions of whole blood separated and prepared within the hospital blood bank or blood center

oxygen carrying components

- red blood cells

- washed red cells

- leukocyte reduced red blood cells (most are)

- frozen red blood cells

- autologous blood

- do not have plasma or platelets

platelet products

- random donor platelets

- single donor platelets

- cold store platelets

- 6 units random = 1 unit single donor

platelet storage

room temp for 5 days