fall bb week 1

strategy 1 for working through ABO discrepancies

repeat ABO typing with new rbc suspension using same sample, excludes tech error, wash rbcs several times with saline

strategy 2 for working through ABO discrepancies

obtain new sample if discrepancy w/ historical blood type, beware of contaimination, rules out tech error

strat 3 for working through ABO discrepancies

review patient’s medical hx- diagnosis, historical blood type, transfusion/plant hx, current meds

strat 4 for working through ABO discrepancies

look for ABO typing reactions- missing, weak, extra, front or back

abo doscrep steps

1 perform clercal check, 2 review patient history, 3 repeat testing on current sample with new suspension, 4 missing or extra- correct tech on current of new sample, 5 transfuse O cells

wrong blood in tube WBIT

tech error identification, collect and test new sample or test another in lab sample collected at a different time

under vs over centrifuge

false neg vs false pos

too cold vs warm

false pos vs false neg

prozone vs postzone

both false neg

extra ag forward

A with aquired B ag, B(A) phenotype, polyagglutination, rouleaux, whartons jelly, cold agg, chimerism

whartons jelly

gelatinous tissue contaiminant in cord blood specimens causing rbcs to stick together, fix by washing 3-4x with saline

fixing cold agglu

wash rbcs with warm 37 C saline, prewarm, partial elution (treat rbcs with chemicals like EGA)

polyagglutination and acquired B

bacterial enzymes alter rbc membranes, check patient diagnosis for sepsis

polyagglutination

hidden T ag on rbc exposed by bacterial/viral enzymes, or T ag activated, fix by testing with control pos= polyagg, neg ab pos

acquired B ag

group A (N-acetylgalactosamine) altered by bacteria resembling B (D-galactose), fix by test with acidified mono/polyclonal anti-B reagent, perform autocontrol, incubate pt rbcs secretor studies showing A not B

B(A) phenotype

B with elevated levels of galactosyltransferase, fix by testing pt rbcs with alternate monoclonal anti-a reagent without MHO4

chimerism

2 diff rbc populations, MF, large fetal maternal hemorrhage, fraternal twins, cannot fix so pt hx is importants

missing or weak ag forward

least common, subgroup, disease, transplantation, age

Ax and Ael

do not react with anti A or anti AB

fixing forward missing or weak rxns

incubate at rt 15-30 min, incub 4 15-30 min with auto control, chnage anti-sera, read microscopically, treat rbcs with enzymes, subgroup detection with lectin

mixed field rxn

transfusion of group O to A B or AB, hsc or bm transplant, A3 phenotype, t-polyagglu rbcs

extra ab

subgroup with anti-A1, cold alloab, coldautoab, rouleaux, IVIG

missing or weak ab

newborn, elderly, pathogenic etiology, immunosuppressive therapy for transplantation