Blood Banking Procedures

A set of vocabulary flashcards for Blood Banking Procedures covering key concepts, definitions, and clinical relevance.

Pretransfusion Testing

The process of ensuring the safest compatible blood product for a patient.

Direct Antiglobulin Test (DAT)

Detects in vivo coating of red cells with IgG and/or complement.

Purpose of DAT

Detects coating of red blood cells to identify hemolytic reactions.

Positive DAT with anti-IgG

Indicates that cells are coated with IgG, seen in autoimmune hemolytic anemia.

Positive DAT with anti-C3

Shows complement coating, typically from cold-reactive antibodies.

Negative DAT result

Indicates no detectable coating or below test sensitivity.

Antibody Screen

Detects unexpected antibodies in patient serum/plasma that may react with donor red cells.

Principle of Antibody Screen

Patient serum is tested against reagent screening cells with known antigen profiles.

Importance of Antibody Screen

Helps prevent hemolytic transfusion reactions and identifies clinically significant alloantibodies.

Screen Pattern: All cells nonreactive

Suggests no detectable unexpected antibody or antibody level too low to detect.

Screen Pattern: One or more cells reactive

Indicates an unexpected antibody may be present.

Antibody Identification

Determines the specificity of unexpected antibodies detected in an antibody screen.

Basic Process of Antibody Identification

Test patient serum against a larger panel of reagent red cells with known antigen profiles.

Dosage in Antibody Identification

Some antibodies react more strongly with homozygous antigen expression.

Antigen Phenotyping

Determines whether a patient or donor red cell sample expresses a specific antigen.

Purpose of Antigen Phenotyping

Supports antibody identification and finds antigen-negative donor units.

Crossmatch

Confirms compatibility between the patient and a selected donor unit before transfusion.

Types of Crossmatch

Immediate Spin, Antiglobulin (Serologic), and Electronic.

Interpretation of Crossmatch

Compatible means the unit may be issued; incompatible needs investigation.

Autocontrol

Patient serum tested against patient red cells to distinguish alloantibody from autoantibody.

Elution

Removes bound antibody from red cells to test antibody specificity.

Enzyme Treatment in Blood Banking

Uses enzymes to alter antigen expression and help separate antibodies.

Prewarm Technique

Warmed serum, cells, and saline to reduce interference from cold-reactive antibodies.

Saline Replacement

Distinguishes rouleaux from true agglutination in patients with abnormal plasma proteins.

Positive DAT with hemolysis

Indicates warm autoantibody, transfusion reaction, HDFN, or drug effect.

Pitfalls in DAT Interpretation

Poor washing can cause false negatives; mixed red cell populations from transfusion.

Common Next Step for Positive Screen, Unclear Panel Fit

Repeat testing, review history, use selected cells or enhanced methods.

Panreactive Panel Problem

Suggests presence of autoantibody, high-incidence, or multiple antibodies.

Incompatible Crossmatch with Negative Screen

May indicate low-incidence donor antigen or ABO error.

High-yield Reminder on Clinical Significance

A historical clinically significant antibody matters even if not currently detectable.

Check Cells

Used to validate negative AHG tests.

Significance of ABO/Rh Typing

Foundational for compatibility before blood transfusion.

Medications affecting Antibody Response

Certain medications can induce immune hemolysis.

Transfusion History

Recent transfusions must be considered in all interpretations.

Clinical Picture Correlation

Laboratory findings must align with patient history and symptoms.

Incubation in Antiglobulin Phase

Essential for confirming the presence of clinically significant antibodies.

Mixed Antibody Patterns

Can complicate the interpretation of antibody screening tests.

Antibody Screening Enhancement Media

Includes LISS, PEG, solid phase, or gel to enhance reactions.

Cold-reactive Antibodies

Antibodies that react at lower temperatures affecting testing.

Thorough Patient History

Critical for accurate pretransfusion testing outcomes.

Hemolytic Disease of Fetus and Newborn (HDFN)

Condition where maternal antibodies attack fetal red blood cells.

Autoimmune Hemolytic Anemia

Condition where the immune system attacks its own red blood cells.

Drug-induced Immune Hemolysis

Hemolysis caused by reactions to certain medications.

Pretransfusion Compatibility Testing

Involves antibody screens and crossmatching to ensure safe transfusion.

Direct vs. Indirect Antiglobulin Test

DAT checks for coating on cells; IAT checks for free antibodies in serum.

Common Causes of Incompatibility

ABO mismatch, alloantibodies, autoantibodies, technical errors.

Serologic Crossmatch Requirement

Necessary when clinically significant antibodies are present.

Warm Autoantibody

An autoantibody that reacts at body temperature.

Cold Agglutinins

Antibodies that cause agglutination at low temperatures.

Ficin and Papain

Enzymes used in blood banking for antibody separation.

High-incidence Antigens

Antigens that are present in a majority of the population.

Low-incidence Antigens

Antigens that are rare and may require special donor searches.

Clinical Workflow Pretransfusion

Involves patient ID, specimen verification, and compatibility testing.

Unexpected Antibodies

Antibodies not anticipated based on patient’s history.

Testing Patterns for Antibody Identification

Must include reviewing reactivity patterns against a cell panel.

Molecular Typing

Used when serologic phenotyping results are unreliable.

Algorithm for Antibody Identification

Stepwise approach to determine the specificity of antibodies.

Intravenous Immunoglobulin (IVIG)

Therapy that can mask the presence of some antibodies.

Time-critical Transfusion

Requires rapid crossmatching to avoid delays.

Patient Demographics

Includes age, sex, and history relevant to transfusion safety.

Role of Reference Laboratories

Provide specialized testing and confirmatory results.

Guidelines for Blood Components Administration

Standard procedures to safely administer transfusions.

Adverse Reactions to Transfusion

Includes febrile reactions, allergic reactions, and hemolytic events.

Monitoring During Transfusion

Essential for early detection of transfusion reactions.

Patient Consent for Transfusion

Need for informed consent before proceeding with transfusion.

Quality Control in Blood Banking

Ensures accuracy and reliability of testing procedures.

Blood Type Verification

Critical to prevent ABO incompatibility.

Pediatric Transfusion Considerations

Special protocols due to higher risks in children.

Phlebotomy Techniques in Blood Banking

Proper techniques reduce contamination risk during blood collection.

Blood Storage Parameters

Specific guidelines for maintaining the viability of blood products.

Blood Product Expiration Dates

Ensures transfusion with effective and safe products.

Emergency Transfusion Protocols

List of steps to expedite blood availability in critical situations.

Traceability in Blood Banking

System to track blood components from donor to recipient.

Documentation in Blood Banking

Critical for legal adherence and quality assurance.

Educational Aspects of Blood Banking

Training requirements for laboratory personnel.

Regulatory Compliance in Transfusion Medicine

Ensures adherence to standards set by governing bodies.