ABO Blood System Course

Lesson 1 • Overview of Major Blood Group Systems

Surveys recognized blood group systems beyond ABO to contextualize ABO's clinical priority. Students distinguish clinically significant from insignificant systems.

Lesson 2 • Immunoglobulin Classes in Transfusion

Describes IgM, IgG, and IgA structure and their roles in blood group serology. Links antibody class to clinical significance in ABO reactions.

Lesson 3 • Genetics of Blood Group Systems

Introduces Mendelian inheritance, codominance, and allelic variation as applied to blood groups. Establishes genetic reasoning used throughout the course.

Lesson 1 • H Antigen Biosynthesis Pathway

Traces the FUT1 and FUT2 gene products that create the H antigen precursor. Understanding H antigen is prerequisite to ABO antigen synthesis.

Lesson 2 • ABO Gene Structure and Alleles

Examines the ABO locus on chromosome 9, key exons, and major allelic variants. Connects gene-level differences to transferase enzyme specificity.

Lesson 3 • Glycosyltransferase Enzyme Activity

Explains how A and B transferases add specific sugars to H antigen to form A and B antigens. Enzyme kinetics underpin subgroup and weak phenotype concepts.

Lesson 1 • Naturally Occurring ABO Antibodies

Describes anti-A and anti-B as predominantly IgM antibodies stimulated by environmental antigens. Establishes why ABO antibodies are present without prior transfusion.

Lesson 2 • Complement-Mediated Hemolysis

Details the classical complement pathway activation by IgM anti-A and anti-B. Explains intravascular hemolysis as the hallmark of acute ABO incompatibility.

Lesson 3 • Immune Anti-A and Anti-B

Covers IgG ABO antibodies arising from transfusion or pregnancy and their clinical significance. IgG class enables placental transfer relevant to hemolytic disease.

Lesson 1 • Rare A and B Subgroups

Surveys Ax, Aend, Am, Ael, Bx, Bm, and Bel phenotypes and their serological profiles. Rare subgroups cause discrepancies requiring advanced resolution strategies.

Lesson 2 • Bombay and Para-Bombay Phenotypes

Explains the Oh (Bombay) phenotype caused by absence of H antigen and its potent anti-H antibody. Para-Bombay variants add complexity to H and secretor testing.

Lesson 3 • Acquired ABO Changes

Describes acquired B phenomenon, polyagglutination, and disease-related antigen weakening. Students recognize clinical conditions that alter ABO serology results.

Lesson 1 • Solid-Phase and Automated Methods

Introduces solid-phase red cell adherence and fully automated ABO grouping platforms. Automation increases throughput and reduces manual transcription errors.

Lesson 2 • Reagent Quality and Controls

Specifies potency, specificity, and avidity requirements for ABO reagents and daily controls. Reagent failure is a root cause of ABO grouping errors.

Lesson 3 • Principles of Hemagglutination

Explains the two-stage sensitization and lattice formation model of hemagglutination. Grounding in reaction physics is essential for interpreting all ABO test results.

Lesson 4 • Forward and Reverse ABO Grouping

Covers cell grouping with anti-A and anti-B reagents and serum grouping with A1 and B cells. Both components must agree for a valid ABO result.

Lesson 1 • Advanced Resolution Techniques

Applies adsorption, elution, enzyme treatment, and molecular genotyping to resolve complex discrepancies. These methods provide definitive answers when serology is inconclusive.

Lesson 2 • Reporting and Blood Release Policy

Defines criteria for releasing blood when a discrepancy is unresolved and documentation requirements. Patient safety depends on clear policies during active discrepancy investigation.

Lesson 3 • Technical Causes and Remedies

Addresses clerical errors, reagent failure, sample quality issues, and procedural mistakes. Technical causes must be excluded before biological explanations are pursued.

Lesson 4 • Classification of ABO Discrepancies

Categorizes discrepancies into four groups based on weak reactions, extra reactions, or missing reactions. Classification directs the correct investigative pathway.

Lesson 1 • ABO in Massive Transfusion

Manages ABO selection when group-specific blood is unavailable during massive hemorrhage. Switching strategies minimize group O red cell depletion while maintaining safety.

Lesson 2 • Neonatal and Pediatric ABO Transfusion

Covers special ABO selection rules for neonates, including maternal antibody and small-volume transfusion. Neonatal physiology requires modified compatibility criteria.

Lesson 3 • ABO Compatibility Rules for Red Cells

States the compatibility matrix for red cell transfusion and the rationale for each pairing. Incompatible red cell transfusion is the most preventable cause of transfusion death.

Lesson 4 • Plasma and Cryoprecipitate Compatibility

Explains reverse ABO compatibility for plasma components containing anti-A and anti-B. High-titer plasma from group O donors poses hemolytic risk to non-O recipients.

Lesson 1 • Hematopoietic Stem Cell Transplant ABO

Addresses major, minor, and bidirectional ABO mismatches in stem cell transplantation. Mismatch type determines transfusion support strategy during engraftment.

Lesson 2 • Passenger Lymphocyte Syndrome

Describes immune hemolysis caused by donor lymphocytes producing antibodies against recipient ABO antigens. Recognition and management prevent serious post-transplant hemolysis.

Lesson 3 • ABO Hemolytic Disease of the Newborn

Focuses on ABO HDN caused by maternal IgG anti-A or anti-B crossing the placenta. ABO HDN is milder than Rh HDN but more common and requires accurate diagnosis.

Lesson 4 • ABO in Therapeutic Apheresis

Covers ABO considerations for plasma exchange, red cell exchange, and stem cell collection. Replacement fluid selection and component compatibility depend on ABO group.