ASCP SBB key terms

A situation in which the forward (red cell) and reverse (serum) ABO typing do not agree, or an expected result is not obtained, requiring investigation and resolution before any blood component is transfused.

The tendency of an antibody to react more strongly with red cells from people who are homozygous for the target antigen than with cells that are heterozygous; seen most often with Rh, Kidd, Duffy, and MNS antibodies.

A procedure that detects antibody or complement already attached to a patient's red cells in the body by washing those cells and adding anti-human globulin, then looking for agglutination.

A procedure that detects antibody in serum or plasma that binds to reagent red cells outside the body; sensitized cells are washed, anti-human globulin is added, and agglutination indicates a positive result.

A technique that removes antibodies bound to red cells so they can be recovered and tested, used in working up hemolytic disease of the fetus and newborn and suspected hemolytic transfusion reactions.

A potentiator added to the indirect antiglobulin test that draws water away from the red cell surface, increasing antibody uptake and helping detect weak antibodies, though it can also cause nonspecific reactivity.

A phenotype in which the D antigen is present on red cells in reduced amounts, often detectable only by the indirect antiglobulin test; testing determines whether the patient should receive D-negative red cells.

A rare phenotype in which a person lacks the H antigen and therefore cannot express A or B on red cells; the serum contains anti-H plus anti-A and anti-B, so only Bombay-compatible (Oh) red cells may be transfused.

A serial dilution method that measures the concentration (titer) or reaction strength (score) of an antibody in serum, used to assess risk in pregnancy, ABO-incompatible transplantation, and selected transfusion situations.

The temporary or permanent exclusion of a prospective blood donor because of medical history, physical findings, medications, travel, or test results that could make donation unsafe for the donor or the recipient.

Removal of white blood cells from a blood component, usually by filtration, to lower the risk of febrile nonhemolytic reactions, HLA alloimmunization, and cytomegalovirus transmission.

Exposure of a cellular blood component to 25 Gy (2500 cGy) to inactivate donor T lymphocytes and prevent transfusion-associated graft-versus-host disease in susceptible recipients.

A plasma-derived component rich in fibrinogen, factor VIII, von Willebrand factor, and factor XIII, made by thawing fresh frozen plasma at 1 to 6 degrees Celsius and collecting the resulting precipitate.

A treatment applied to a blood component that inactivates or removes infectious agents such as viruses, bacteria, and parasites while preserving the therapeutic function of the cells or proteins.

An automated process that separates and collects one specific blood component, such as platelets, plasma, or red cells, from a donor or patient while returning the remaining blood.

A computer-based method of confirming ABO compatibility between a patient and a red cell unit using validated software, historical blood types, and a current negative antibody screen, without serologic testing.

Noncardiogenic pulmonary edema that develops during or within six hours of transfusion, often linked to donor antibodies directed against recipient HLA or neutrophil antigens.

Hydrostatic pulmonary edema caused by volume overload that occurs during or within six hours of transfusion, most often in elderly patients or those with cardiac or renal impairment.

A preparation of anti-D given to D-negative mothers to prevent alloimmunization to fetal D-positive red cells, and occasionally given to D-negative patients receiving D-positive platelets.

A preplanned, standardized approach for rapidly delivering balanced blood components to a patient with severe hemorrhage, typically using defined ratios of red cells, plasma, and platelets with set activation triggers.

A multidisciplinary, evidence-based strategy that optimizes hemoglobin, minimizes blood loss, and reserves transfusion for appropriate indications in order to improve patient outcomes.

Selecting red cell units that match a patient's phenotype or genotype for antigens beyond ABO and D, such as C, E, and K, to prevent alloimmunization in chronically transfused patients.

An antibody directed against human leukocyte antigens that can cause platelet refractoriness, transfusion reactions, and graft rejection; testing guides selection of antigen-matched or crossmatch-compatible products.

A formal quality system process for evaluating, approving, implementing, and documenting changes to procedures, equipment, or computer systems so that validated processes are not inadvertently compromised.

Documented evidence that a process, method, or system consistently meets predetermined specifications, typically shown through installation qualification, operational qualification, and performance qualification stages.

An external quality assessment in which a laboratory tests unknown specimens supplied by a provider and compares its results with those of peer laboratories to demonstrate ongoing testing competence.

A structured investigation that identifies the underlying causes of an error or adverse event and leads to corrective and preventive actions rather than simply assigning individual blame.

An international standard for labeling blood and tissue products that provides globally unique donation identifiers, standardized product codes, and both eye-readable and machine-readable information.

The process of identifying recipients of blood from a donor later found to be infected or otherwise at risk, then notifying and testing those recipients as appropriate.

A mandatory report submitted to the FDA when an error or accident in manufacturing, testing, or distribution may have compromised the safety, purity, or potency of a blood product.

A standardized, FDA-recognized document supplied with blood components that describes the product, its indications, and the risks and precautions associated with its use.

A molecular method that detects pathogen RNA or DNA in donor blood during the window period, giving greater sensitivity than serologic antigen or antibody assays.

Determining the specific alleles present in a person's DNA; in immunohematology, predicting red cell antigen expression from a blood sample when serologic phenotyping is unreliable or impossible.

Molecular testing of the RHD gene used to distinguish weak D types, partial D variants, and truly D-negative individuals in order to guide transfusion and Rh immune globulin decisions.

A molecular typing method in which primers designed to match particular alleles generate a PCR product only when that allele is present, allowing antigen typing from DNA.

Molecular analysis, usually by short tandem repeat or Y-chromosome markers, that measures the proportion of donor and recipient cells present after hematopoietic stem cell transplantation.

A flow cytometric measurement of CD34-positive cells in peripheral blood, bone marrow, or an apheresis product, used to judge stem cell yield and time collections.

Collection of stem cells from peripheral blood with an apheresis device after mobilization with growth factors or chemotherapy, for autologous or allogeneic transplantation.

Freezing cells or tissues, often with dimethyl sulfoxide as a cryoprotectant, so that they remain viable for later thawing and clinical use, as with stem cells and rare red cell units.