Blood Bank Exam 1: ABO discrepancies

what are the three causes of ABO discrepancies

past history doesnt match present result

forward and reverse typing dont match

mixed field

what can be acceptably transfused while a discrepancy is being figured out in the case of an emergency

group O red cells

AB plasma

forward typing tells us about the patients

antigens

reverse typing tells us about the patients

antibodies

discrepancies are either due to a ____________ Ab/Ag or ______________ Ab/Ag

missing or weak

unexpected or extra

what are four things that we can do to resolve an ABO discrepancy of any type

repeat testing

look at patient history

determine if the forward or reverse is correct

perform testing to resolve the discrepancy

do you believe the forward or reverse?

Anti-A: 0

Anti B: 4

A1 cell: 2

B cell: 3

forward

do you believe the forward or reverse?

Anti-A: 2

Anti-B: 3

A1 cell: 0

B cell: 4

reverse

is the forward or reverse usually more trustworthy?

forward

what is one method that is commonly used to resolve ABO discrepancies when retesting the sample

use another manufacturer of reagents

information about the Anti A,B reagent

monoclonal

single clone of Anti-AB

initial testing of serum or plasma we can do to resolve ABO discrepancies and enhance the reaction

test O cells

perform mini cold panel

what causes mixed field agglutination

transfusion (most common cause)

all non-O transfused with O cells

A3 or B3 phenotype

fetal/maternal bleed

hematopoietic progenitor cell transplant (HPC)

chimera

what is chimerism

people who are twins may have mixed field since two cell populations are being made.

in the gel test what does mixed field look like

some at the top and some at the bottom

in the liquid microtiter test what does mixed field look like

dot with cloud around it

what is a antigen

super b gene

A antigen has what extra sugar

A sugar (GalNAC)

B can be acquired through this method

bacterial infection (gut)

mutations in the a subgroup happen in mostly these exons

6 and 7

what are cord cells

cells from the umbilical cord of a baby which are tested by the lab

number of antigens per RBC in order of most to least

A1 adult (>2,000,000)

A1 cord

A2 adult

A2 cord

A1B adult

B adult

in cold autoantibody the O cells would be

positive

what causes rouleaux cells

high protein

multiple myeloma

waldenstrom's

missing antibodies can be caused by

age of the patient (infant, old age)

immune compromised

acidified anti B is used to look for

acquired B

lectins are used to look for

A2 and other A subgroups

methods of resolving ABO discrepancies

treat with chemicals to remove the antibody

look at RBC in plasma to assess rouleaux

phenotype to look for alloantibody

prewarm the reverse type

test antigen

saline replacement for rouleaux

how does patient history impact what we might see?

history of transfusion

mixed field

how does patient history impact what we might see?

history of infusion with ABO compatible products

extra antibody

how does patient history impact what we might see?

history of receiving IVIG

extra antibody

how does patient history impact what we might see?

history of HPC transplant

mixed field

missing antibody

how does patient history impact what we might see?

history of AIHA

extra antigen

coated RBCs

how does patient history impact what we might see?

history of multiple myeloma

axtra antibody (rouleaux)

how does patient history impact what we might see?

history of immunosuppressive disorder

missing antibodies

how does patient history impact what we might see?

history of leukemia / Hodgkin's

weak or missing antigens

how does patient history impact what we might see?

history of infection/digestive tract

acquired B