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PA21.1-6 | Welcome to ABO & Rh Blood Group Systems
Learning Objectives
- Explain the biochemical basis of ABO blood group antigens and the role of glycosyltransferases.
- State Landsteiner's law and describe the natural isohaemagglutinins (anti-A, anti-B) with their immunoglobulin class.
- Describe the inheritance pattern of ABO blood groups and recognise the Bombay phenotype.
- Explain why ABO incompatibility causes immediate intravascular haemolysis.
- Describe the Rh system, the clinical significance of the D antigen, and the mechanism of haemolytic disease of the newborn (HDN).
- Outline the principle of antigen-antibody agglutination as the basis for blood grouping.
INSTRUCTIONS
Blood transfusion is one of the most common — and potentially most dangerous — clinical procedures. Getting the blood group wrong is a preventable cause of patient death. Understanding why ABO and Rh incompatibility cause different patterns of haemolysis (immediate vs. delayed; intravascular vs. extravascular) will anchor your clinical reasoning in transfusion medicine for the rest of your career. This module builds the biochemical and immunological foundation; SDL 2 covers compatibility testing.
References
- Robbins & Kumar: Basic Pathology, 11th ed., Ch 11 (Red Cell Disorders) (textbook)
- Wintrobe's Clinical Hematology, 14th ed., Ch 38 (Blood Group Antigens) (textbook)
- Hoffbrand & Moss: Essential Haematology, 8th ed., Ch 27 (Blood Transfusion) (textbook)
Version 2.0 | NMC CBUC 2024