ASCP BB cheat sheet

ABO is on chromosome 9; FUT1 (H) is on chromosome 19; FUT2 determines secretor status and ABH expression in secretions.

IgG antibodies cross the placenta and react optimally at 37°C by IAT/AHG; IgM antibodies agglutinate at room temperature and fix complement.

RHD and RHCE are on chromosome 1; D is highly immunogenic; weak D management depends on policy and genotype.

Kell (KEL) is on chromosome 7; anti-K is IgG, can cause severe HDFN, and can suppress erythroid progenitors.

Duffy (FY) is on chromosome 1; Fy6 is the Plasmodium vivax receptor; Fy(a-b-) is common in West African ancestry.

Kidd (JK) is on chromosome 18; anti-Jk often shows dosage and evanescence and causes delayed hemolytic transfusion reactions.

Lewis antigens are adsorbed from plasma onto RBCs; anti-Lea and anti-Leb are usually IgM and can bind complement.

MNS uses glycophorin A/B on chromosome 4; anti-M is often naturally occurring IgM; anti-S and anti-s are IgG and clinically significant.

Antibody detection uses screening RBCs at 37°C and AHG; a positive screen is resolved with panel cells, autocontrol, and history.

In panel rule-out, a positive cell excludes a specificity unless another antibody explains it; dosage-positive cells are needed for Duffy, Kidd, Rh, and MNS.

A positive autocontrol with panreactivity suggests autoantibody; allogeneic adsorption can reveal an underlying alloantibody.

Ficin or papain enhances Rh, Kidd, Lewis, and P1 and denatures Duffy, MNS, and Xga; DTT denatures Kell, Lutheran, and Dombrock.

Clinically significant antibodies are IgG reactive at 37°C/AHG and associated with HTR or HDFN, such as anti-D, anti-K, anti-Jka, and anti-Fya.

Titer endpoint is the reciprocal of the highest dilution with visible reactivity; titer and score monitor antibody strength.

Elution methods include acid, heat, cold, and Lui; eluates identify antibody on DAT-positive RBCs.

Neutralization uses soluble antigen: saliva for Lewis, hydatid cyst fluid for P1, and human milk for anti-I.

Type and screen includes ABO/Rh and antibody screen; crossmatch is added when antibody history or a positive screen is present.

Immediate-spin crossmatch at room temperature primarily detects ABO incompatibility; AHG crossmatch is required for clinically significant antibodies.

Electronic crossmatch requires two concordant ABO/Rh typings, no clinically significant antibody history, a negative screen, and a validated system.

A pretransfusion sample is generally valid for 3 days if the patient was transfused or pregnant within the prior 3 months; policy may extend validity.

Group O negative RBCs are the universal RBC donor; group AB plasma is the universal plasma donor; ABO-identical platelets are preferred.

ABO-incompatible plasma in RBC units can hemolyze recipient RBCs when anti-A or anti-B titers are high.

Transfusion reaction workup includes pre- and post-transfusion serum, urine, returned unit, DAT, and clerical checks.

Crossmatch incompatibility can result from alloantibody, autoantibody, rouleaux, or clerical error.

RBC units are stored at 1-6°C; additive-solution RBCs may be stored up to 42 days, and CPDA-1 RBCs up to 35 days.

Platelets are stored at 20-24°C with continuous agitation for up to 5 days; pH must be at least 6.2 at expiration.

Plasma is frozen at <= -18°C; thawed plasma is stored at 1-6°C and used within 24 hours.

Cryoprecipitate is prepared from fresh frozen plasma and contains fibrinogen, factor VIII, von Willebrand factor, and fibronectin.

Leukoreduction reduces residual white cells to less than 5 x 10^6 per unit and lowers febrile nonhemolytic reaction risk.

Irradiation at 25 Gy (2500 cGy) to the midplane prevents transfusion-associated graft-versus-host disease.

Storage lesion includes falling 2,3-DPG, rising potassium, falling pH, and rising lactate.

Glycerolized RBCs are frozen and, after deglycerolization, are stored at 1-6°C for 24 hours.

Acute hemolytic reaction presents with fever, chills, flank pain, hypotension, and hemoglobinuria; stop the transfusion and maintain urine output.

Febrile nonhemolytic reaction is a temperature rise of at least 1°C without hemolysis and is reduced by leukoreduction.

Allergic reaction causes urticaria or pruritus; anaphylaxis suggests IgA deficiency with anti-IgA.

TACO causes dyspnea, hypertension, and pulmonary edema within 6 hours; treatment includes oxygen and diuretics.

TRALI causes hypoxemia and bilateral infiltrates within 6 hours without volume overload; donor antibodies are often implicated.

Delayed hemolytic reaction occurs 3-14 days after transfusion with falling hemoglobin, positive DAT, and a new alloantibody.

Bacterial contamination is most common in platelets and can present as sepsis; culture the unit and discard it.

TA-GVHD is prevented by irradiated cellular components and presents with rash, pancytopenia, and fever.

HDFN is most severe with anti-D; ABO HDFN is most common; anti-K and anti-c can also cause severe disease.

A 300-microgram dose of RhIG neutralizes about 15 mL of fetal RBCs or 30 mL of fetal whole blood.

RhIG is given at 28 weeks and within 72 hours postpartum; it is not given to an already sensitized woman.

Kleihauer-Betke testing detects fetal hemoglobin resistant to acid elution and quantifies fetal-maternal hemorrhage.

MCA peak systolic velocity greater than 1.5 multiples of the median suggests moderate to severe fetal anemia.

Delta OD450 by Liley curve assesses amniotic fluid bilirubin in alloimmunized pregnancies.

Cord blood in HDFN shows a positive DAT, elevated bilirubin, and anemia; ABO HDFN is usually mild.

Fetomaternal hemorrhage screening uses rosette testing or flow cytometry; Kleihauer-Betke is used for quantification.

Donor infectious testing includes HIV-1/2 Ag/Ab, HCV Ab and NAT, HBV surface antigen and NAT, syphilis, HTLV, and WNV NAT.

NAT shortens window periods to about 9-11 days for HIV, 3-7 days for HCV, and 20-25 days for HBV.

Donor hemoglobin must be at least 12.5 g/dL for women and 13.0 g/dL for men; hematocrit must be at least 38%.

Donor vital signs: temperature <=37.5°C, systolic 90-180 mm Hg, diastolic 50-100 mm Hg, and pulse 50-100 beats/min.

Whole blood donation interval is 8 weeks; double RBC apheresis interval is 16 weeks.

Travel to a malaria-endemic area generally causes a 12-month deferral unless exemption criteria are met.

A confirmed positive infectious disease test requires donor deferral, unit discard, and lookback as required.

Donor screening includes a health questionnaire, physical examination, and review of medications and travel.

FDA regulates blood establishments under 21 CFR 606; AABB and CAP provide accreditation and standards.

Antisera quality control includes daily reactivity and specificity checks with known RBCs.

Proficiency testing is required for ABO/Rh, antibody screen, crossmatch, and infectious disease testing.

Competency assessment must occur before patient testing and at least annually thereafter.

CAPA includes root cause analysis, corrective action, preventive action, and documentation of effectiveness.

Equipment calibration and maintenance records must be retained and reviewed.

Blood inventory uses FIFO and expiration monitoring; improperly stored units are quarantined.

Validation is required for computer crossmatch, LIS interfaces, and new methods before clinical use.

FDA regulates blood establishments under 21 CFR 606; AABB and CAP provide accreditation and standards.

Antisera quality control includes daily reactivity and specificity checks with known RBCs.

Proficiency testing is required for ABO/Rh, antibody screen, crossmatch, and infectious disease testing.

Competency assessment must occur before patient testing and at least annually thereafter.

CAPA includes root cause analysis, corrective action, preventive action, and documentation of effectiveness.

Equipment calibration and maintenance records must be retained and reviewed.

Blood inventory uses FIFO and expiration monitoring; improperly stored units are quarantined.

Validation is required for computer crossmatch, LIS interfaces, and new methods before clinical use.