Problem Resolution Dept Exam Flashcards
calculate number of units to test
2/(frequency in decimal form)
ex) 2 units of blood with 34% frequency of Ag:
2/0.34 = 5.9 = six units
select control cells for Ag typing
positive: heterozygous positive
negative: negative
When can you do a selected cell panel?
historical Ab
only 1 positive necessary to confirm
select cells in order to r/o other Abs
prewarm technique use
only for XM
careful not to prewarm a new IgM away
what is extended RT incubation, or 4°incubation, used for?
weak reverse type
requires controls
auto-adsorption cannot be used when…
tx in the last 3 months
instead, use allogeneic adsorption
instances when allogeneic adsorption is used
- short sample
- tx in last 3 months
phenotyping must be done on a —– sample
pre-tx
example of an enzyme tx
DTT for darzalex
destroys K
acidification of serum
increases anti-M activity
which antigens are neutralized using blood group substances?
P1
Lewis
urine Sda
AHG XM used for…
current OR clinically significant Ab (even historical) from ABS/Hx
3 reasons for DAT+
- HDFN
- transfusion rxn
- autoAb
how to perform weak D if DAT+
EGA treat cells
last wash testing purpose
control; tells us that we washed enough, and the Ab detected in the eluate was coating the RBCs, not present in plasma
3 causes of IS problems
- IgM alloAb
- cold autoAb
- rouleaux
2 causes of AHG problems
- IgG or C’ binding alloAb (low-freq)
- warm autoAb
how to release blood when a patient has a warm autoAb
use adsorbed plasma
neat plasma will be incompatible
requires emergency release by Dr
how do you determine which tests to run after trxn?
investigate what is different between the “pre” sample and the “post” sample
acute hemolytic trxn
- red cell incompatibility
- chills, fever, hemoglobinuria, hypotension, renal failure, oliguria, DIC, back pain, pain along infusion site, anxiety
febrile nonhemolytic trxn
- Ab to donors’ WBCs or cytokines in a plt bag
- fever, chills, h/a, vomiting
- avoid with leukocyte reduction
urticarial trxn
- Ab to to donor’s IgE
- urticaria, flushing, angioedema
anaphylactic trxn
- Ab to donor’s IgA, haptoglobin or C4
- hypotension, urticaria, respiratory distress, angioedema, abd pain, anxiety
- avoid by washing product or using IgA deficient plasma
TRALI
- transfusion-related acute lung injury
- donor’s Ab to WBCs (from plasma products); HLA related; no female plasma used
- bilateral pulmonary edema, hypoxemia, resp failure, hypotension, fever
delayed hemolytic trxn
- anamnestic response to RBC Ag
- fever, decreasing Hgb, new positive ABS, jaundice, DAT+/=
alloimmunization
- delayed
- immune response to foreign Ag on RBCs, WBCs or plts
- ABS+, platelet refractoriness, delayed HTR, HDFN
GVH disease
- delayed
- donor lymphs attack host tissues
- erythroderma, maculopapular rash, anorexia, n/v/d, hepatitis, pancytopenia, fever
- avoid with irradiation
TRIM
- transfusion-related immune modulation
- delayed
- incompletely understood; donor WBC or plasma factors interact with host immune system
- transient immunosuppression
- avoid with leukocyte reduction
transfusion-related sepsis
- acute
- fever, chills, hypotension
TACO
- transfusion-associated circulatory overload
- dyspnea, cough, cyanosis, tachycardia, HTN, h/a
nonimmune hemolysis
- acute
- physical/chemical destruction of blood
- heating, freezing, hemolytic drug
- hemoglobinuria, hemoglobinemia
air embolus
- sudden SOB, acute cyanosis, pain, cough, HTN, cardiac arrhythmia
hypothermia
- cardia arrhythmia
hypocalcemia
- rapid citrate infusion; delayed metabolism of citrate
- paresthesia, tetany, arrythmia
- tx: TUMS
iron overload
- transfusion-dependent patients
- DM, cirrhosis, cardiomyopathy
weak extra reverse cell rxn
ABS=
- weak isoagglutinin
- extended RT incubaton/4° incubation
- children, elderly
weak extra reverse cell rxn
ABS+
- cold alloAB
- ABID
- retest with Ag= cells
- (commonly happens with anti-M)
weak A1 reverse cell rxn on a patient that types A or AB
- subgroup A2
- test with 3 A1, 3 A2 cells
- look at transfusion hx
- test with A1 lectin
weak extra reverse cell rxn
all ABS cells +
- cold autoAb: cold autoadsorption or mini cold panel
- rouleaux: saline replace
MF forward type
- check tx hx, HPC transplant, or obstetrical pt
- may be A3; test A1 lectin
extra forward type reactivity
- wash 3-4 times and repeat
- if weak anti-B reaction, could be acquired anti-B; check hx for GI issues or GN infection
- repeat with monoclonal acidified anti-B
- perform autocontrol
type O with strong ABS+ with all cells
- possible Bombay type, with anti-H
- ABID + type with anti-H
IgG antigens
- Rh
- Ss
- Duffy
- Kidd (also bind C’)
- Lub (high freq)
- Kell
IgM antigens
- Lewis
- MN
- P1
- Lua
- I (cold auto)
tends to disappear with time; may be only historical, not current
Kidd
used to enhance any IgM rxn
extended RT or 4° incubation
like weak D, a DAT+ gives false positives
phenotyping a patient’s cells
anti-CD38 drug that creates panagglutinins
treat with what?
darzalex
DTT (inactivates Kell)
special consideration for a darzalex patient that was not phenotyped before tx
give K= blood
enhanced by enzyme tx
- Kidd
- Rh (some)
- Ss (variable)
destroyed by enzyme tx
- Duffy
- MN
unchanged by enzyme tx
Kell
used when certain antibodies are preventing others from being detected
neutralization procedures
Lewis and P1 – blood group substance
Sda – urine
required when using neutralization procedures
controls, as the substance may dilute out an Ab
use —- to enhance auto-adsorption
PEG
for ————, you need a large sample
auto adsorption
requirements for units used in allogeneic adsorption
each antigen must have a negative in at least one unit used
3 units: R1R1, R2R2, rr
anti—— is frequently an IgM alloantibody discovered at IS XM
anti-M
XM may detect IgG when…
it is against a low-freq that is not represented on the screening cells
unit problem that can cause incompatible XM
donor is DAT+
drug that frequently causes DAT+
TZP
perform an eluate if DAT+ with…
- IgG
- C3, if tx in last 3 weeks
antigen that may cause C3+ DAT, and IgG=
Kidd
