blood bank

naturally occurring antibodies are most often of which immunoglobulin class?

IgM

which antibody do type A individuals make naturally?

Anti-B

which antibody do type B individuals make naturally?

Anti-A

which antibodies do type O individuals make naturally?

Anti-A,B (IgG)

which antibody do type AB individuals make naturally

none

what is the inheritance pattern for A and B genes

A and B are codominant expression

immunodominant sugar for A antigen

N-acetylagalactae

Immunodominant sugar for B antigen

galactose

concentration of H antigen

O, A2, A2B, B, A1, A1B

what does forward blood typing identify?

red cell antigens

what does reverse blood typing identify

serum/plasma antibodies

what causes ABO subgroups

genetic mutations, creating alternate alleles

what is the most common A subgroup, after A1?

A2

what is the difference between A1 and A2 subgroups

A2 has transferase enzyme that is less potent then A1 so less of a H structure being converted

what is the anti-A1 lectin

Dollichos biflourus

what lectin agglutinates B cells?

Bandeiraea simplicifolia

what lectin agglutinates type O cells?

Ulex europaeus

what are some techniques helpful to differentiate remaining A subgroups?

forward with Anti-A, Anti-AB, Anti-H, presence of ABO antibodies and Anti A, adsorption and salvia studies

what are some technique to differentiate B subgroups?

forward with Anti-B, Anti-AB, Anti-H, presence of ABO antibdoies and Anti B, absorption and salvia studies

why is it important to identify subgroups?

if not identified, could be falsely as O which would bad for donors

what causes Bombay phenotype

hh or mutated HH (less common)

what do individuals with Bombay phenotype type as

will type as O

what can be used to confirm if a patient is a Bombay phenotype?

lectin Ulex europaeus (Bombay cells will not react)

what blood type is safe to transfuse an individual with Bombay phenotype?

only red cells from other Bombay

what is the difference between Bombay and para-Bombay

mutated H with or without sese or hh with Sese

what are some examples of typing discrepancies?

extra positive reactions or missing

what can cause typing discepancies

problems with plasma, RBC or both

sources of technical errors that can result in ABO discrepancies

wrong patient, cell suspensions, clerical errors

what are common causes of missing forward type reaction

ABO subgroups, leukemia, lymphoma, transfusions, transplant, excess of ABH antigens

what is acquired B phenomenon commonly associated with?

GI diseases and siepticemia

what are some causes of rouleux

elevates proteins (seen in multiple myeloma, waldenstroms), fibrinogen, plasma expanders (dextron), whartons jelly

what are some common causes of extra reactions in the forward type

acquired B, Rouleaux, strong cold reacting autoantibodies

what are some common causes of missing reactions in the reverse type?

age (newborn or elderly), agammaglobulinemia or immunodeficiency disease, hypogammaglobulinemia (leukemia), immunosuprpresive drugs, transplant, chimerism in twins, transfusion, fetal-maternal bleed

what are some common causes of missing reactions in the mixed field

leukemia, ABo subgroups, true chimerism

what are some common causes of extra reactions in the reverse type?

cold or room temp reacting alloantibodies or autoantibodies, ABO subgroups, transfusion, rouleaux,

what are some methods to make the missing reaction occur

extended incubation at room temperature, incubate at 4C, add more reagent, wash and repeat, different reagent, run additional

what are some methods to eliminate extra antigen reactions

wash and repeat, warm at 37C, different reagent, run additional

what are some methods to make missing antibody reaction show up

4 +1 add additional plasma, extend incubation time at room temperature, incubate at 4C (4 + 1 is two more drops of plasma and 1 drop RBC)

what are some methods to eliminate extra antibody reactions

saline replacement technique, test with additional reagents, antibody identification techniques (test in panel of O cells) (pos antibody screen, DAT, auto control)

what can be done if a typing discrepancy cannot be resolved, but blood is needed

if canno tbe resolved TRO/TRAB is the safest bet