ASCP SBB cheat sheet

ABO groups: A has anti-B, B has anti-A, O has anti-A plus anti-A,B, AB has neither; these isohemagglutinins are IgM and react at immediate spin or room temperature.

D is the most immunogenic red cell antigen; up to ~80% of D-negative recipients exposed to D-positive red cells form anti-D.

Only IgG1 and IgG3 cross the placenta and activate complement efficiently; IgM antibodies such as anti-A and anti-B do not cross the placenta.

The indirect antiglobulin (IAT) test detects IgG in serum; IgG-sensitized check cells must agglutinate in every negative AHG tube to prove the reagent was active.

Enzyme treatment with ficin or papain destroys Duffy (Fya/Fyb) and MNS antigens while enhancing Rh, Kidd, Lewis and P1 reactions.

Dosage effect: antibodies to Rh, Kell, Duffy, Kidd and MNS react more weakly with heterozygous cells, so homozygous cells are selected for rule-out panels.

The direct antiglobulin test detects in vivo sensitization with anti-IgG and/or anti-C3d; an eluate from the patient's cells identifies the bound antibody.

Lewis antibodies are IgM, bind complement, are usually clinically insignificant, and are neutralized by plasma-containing components.

Kidd antibodies (Jka/Jkb) characteristically fall below detection yet cause severe delayed hemolytic reactions on re-exposure.

Donor eligibility: hemoglobin at least 12.5 g/dL (female) or 13.0 g/dL (male), hematocrit 38%/39%, weight at least 50 kg, whole blood interval 56 days.

Whole blood collection is 450-500 mL plus samples, collected into CPD, CP2D or CPDA-1 with continuous mixing; volume accuracy within ±10%.

Red cells stored at 1-6°C: CPDA-1 for 35 days, additive solutions (AS-1, AS-3, AS-5) for 42 days, irradiated units 28 days, deglycerolized units 24 hours.

Platelets are stored at 20-24°C with continuous agitation for 5 days (7 days with an approved pathogen-reduction system) and are never refrigerated.

FFP is frozen within 8 hours of collection (FP24 within 24 hours), stored at -18°C or colder for up to 12 months, and used within 24 hours after thawing.

Cryoprecipitate is the cold-insoluble fraction of FFP and contains fibrinogen, factor VIII, von Willebrand factor, factor XIII and fibronectin.

Leukoreduction leaves fewer than 5 x 10^6 residual white cells per unit and reduces febrile nonhemolytic reactions, HLA alloimmunization and CMV transmission.

Irradiation delivers 25 Gy (2500 cGy) to 50 Gy to the center of the container, inactivating donor T cells that cause transfusion-associated GVHD.

Donor screening serology plus nucleic acid testing covers HIV, HCV, HBV, HTLV, syphilis, West Nile virus, Trypanosoma cruzi and, where required, Zika.

Restrictive red cell threshold is 7 g/dL for stable adults, 8 g/dL for cardiac surgery, orthopedic surgery and stable cardiovascular disease.

Platelet triggers: 10 x 10^9/L for prophylaxis, 20 x 10^9/L before central line or lumbar puncture, 50 x 10^9/L for major surgery, 100 x 10^9/L for CNS or ocular surgery.

Plasma dose is 10-15 mL/kg and is indicated for coagulopathy with bleeding or INR greater than 1.5, not for volume expansion alone.

Cryoprecipitate dosing is about 1 unit per 5-10 kg, raising fibrinogen roughly 50-100 mg/dL; target fibrinogen is above 150 mg/dL.

Febrile nonhemolytic reaction is the most common transfusion reaction; acute hemolytic reaction from ABO incompatibility is the most serious and usually stems from clerical error.

TACO and TRALI both cause dyspnea with bilateral infiltrates within 6 hours; TACO shows hypertension and elevated BNP, TRALI is noncardiogenic with fever and hypotension.

Massive transfusion is 10 or more red cell units in 24 hours; balanced 1:1:1 red cell to plasma to platelet ratios limit dilutional coagulopathy.

Washed red cells reduce extracellular potassium and remove IgA and plasma protein, for severe hyperkalemia, IgA deficiency or recurrent anaphylactic reactions.

Routine premedication with acetaminophen or diphenhydramine does not reliably prevent reactions and is not recommended as a standing order.

Anti-A, anti-B and anti-D reagents are quality controlled each day of use against known positive and negative red cells before patient testing.

Antibody screen and panel cells, AHG reagent and enhancement media are checked for reactivity and specificity per the manufacturer's and laboratory's procedures.

Levey-Jennings charts with Westgard rules detect error: 1-3s rejects the run, 2-2s rejects, R-4s rejects, while 4-1s and 10x flag systematic shift.

Method validation documents accuracy, precision, reportable range, reference intervals and interference before a new test goes live.

CLIA mandates enrolled proficiency testing; an unacceptable score requires documented investigation and corrective action.

CAPA links root cause analysis to the corrective action taken for a nonconformity, the preventive action against recurrence, and a verified effectiveness check.

Continuous temperature monitoring with alarms is required for blood storage: 1-6°C for red cells, 20-24°C with agitation for platelets.

Transfusion service records, including donor and recipient information and crossmatch results, are retained for 10 years.

FDA 21 CFR 606 covers current good manufacturing practice, 610 covers general biological products, and 630/640 cover serological reagents and blood products.

A donation- or transfusion-related fatality must be reported to FDA CBER as soon as possible and no later than 7 days after the initial report.

Other errors and accidents in manufacturing are reported to FDA under 21 CFR 606.171 within 45 calendar days of discovery.

CLIA classifies immunohematology as high-complexity testing, requiring qualified personnel, proficiency testing and documented competency assessment.

OSHA 29 CFR 1910.1030 requires an exposure control plan, hepatitis B vaccination offered to at-risk staff, safer devices and post-exposure evaluation.

ISBT 128 supplies a globally unique, check-character-validated donation identifier and standardized product codes for traceability from vein to vein.

Look-back traces recipients of prior donations from a donor later found positive for HIV, HCV or HBV and notifies their physicians.

AABB Standards and accreditation, FDA registration and licensure, CAP and Joint Commission surveys form the overlapping oversight framework for blood banks.

Donor nucleic acid testing shortens window periods to about 11 days for HIV, 7 days for HCV and 20-30 days for HBV compared with serology.

Minipool NAT (pools of 6 or 16) balances cost and sensitivity; individual donation NAT further shortens the window period and is used for high-risk or look-back settings.

PCR-SSP and reverse sequence-specific oligonucleotide methods genotype RHD, RHCE, ABO, Kell, Duffy, Kidd and MNS when serology is unreliable.

RHD genotyping distinguishes weak D types 1, 2 and 3, which do not make anti-D and can be managed as D-positive, from partial D variants that can.

Cell-free fetal DNA in maternal plasma allows fetal RHD genotyping and targeted anti-D immune globulin in D-negative pregnancies.

HLA typing by NGS or SSO supports platelet refractoriness workups and TRALI investigations; HPA typing supports neonatal alloimmune thrombocytopenia.

Short tandem repeat PCR chimerism testing quantifies donor and recipient DNA fractions after hematopoietic stem cell transplant.

Hematopoietic stem cell sources are bone marrow, G-CSF-mobilized peripheral blood and cord blood; mobilized peripheral blood is standard for autologous collection.

Engraftment generally requires at least 2-5 x 10^6 viable CD34-positive cells per kilogram of recipient weight.

Cryopreservation uses 5-10% DMSO with controlled-rate cooling near -1°C per minute, then storage at -150°C or colder in liquid nitrogen vapor.

Cord blood transplant requires roughly 2.5 x 10^7 total nucleated cells per kilogram and at least a 4 of 6 HLA match for reliable engraftment.

Major ABO incompatibility (donor red cells vs recipient plasma) requires red cell depletion of the graft; minor incompatibility requires plasma reduction.

CAR-T cell toxicities are cytokine release syndrome, with fever, hypotension and hypoxia, and ICANS, with neurologic deficits and encephalopathy.

Post-thaw products must show at least 70% viability by trypan blue, and DMSO is often washed out before infusion to limit infusion toxicity.