discrepancies Flashcards
weak/ missing antibody
-most common
from: patient age, immune status, current/past diseases
-recent plasma exchange: AB plasma doesn’t have anti-b or anti-a
resolution for weak antibody/ missing
add 1-2 drops of plasma and incubate at RT longer
unexpected antibody
causes: cold reactive antibodies, rouleaux, anti-a1, passively acquired anti-a or anti-b from platelets
report type as A2
if patient serum shows no reactivity with dolichos lectin nad no reactivity with A2 cells
if screening cell is positive at IS phase its
cold alloantibody
if all cells have reactivity including screening cells and auto control
cold autoantibody
cold alloantibody resolution
run full panel since screening cell negative and antigen type units for negative antigen you found against plasma of patient
cold autoantibody resolution
report cold autoantibody or some places runs warm settled cell OR autoabsorb
cold autoantibody settled cell reading
set up plasma with A1 cells, B cells and SC1, incubate 37 degrees for 1 hour and read agg.
weak/missing antigen
cause: recent transfusion with type O cells that reduced reactivity/mixed field, leukemia, HPC transplants from group O donor
weak/missing antigen solution
increase RT incubation time, incubate 4 C include group O cell and autocontrol
extra antigens
HPC transplant with incompatible donor (ABO is 2nd to HLA in marrow transplant)– continues to make donor type
extra antigen resolutions
HPC transplant– confirm patient history and given history type
acquired B phenotype
acidifying human anit-b eliminates reactivity with acquired b-cells but keeps reactivity with true B cells (give type A cells)
bombay will show reactivity
anti-H, anti- A, anti-B cause has nothing
bombay and group o cells are
incompatible (O has H)
why is Rh testing invalid or history does not match?
1) patient is weak d +
2) patient has rouleaux- auto control positive
3) patient’s DAT +
4) mixed field on cord blood (contamination from mother)
weak d
<3 + investigated; only care now if donor unit or cord blood has weak testing
weak d test resolution
will positive once you take it all the way to AHG phase
rouleaux resolution and reasoning
when Rh control is positive — wash patient’s cells and repeat test
patient DAT resolution
tubes will have identical agg. ; suspect poor washing and perform DAT again
if donor unit has positive DAT
quarantine and report to blood center
if cord blood positive DAT
check mother’s type and screen – send to reference lab