Lewis Blood Group System

This Medical Laboratory Science lesson in Blood Bank supports laboratory science learning and laboratory interpretation for medical laboratory students and professionals.

Explain Lewis antigens Le(a)/Le(b) as plasma-adsorbed structures, their relationship to secretor status, and why Lewis antibodies are usually clinically insignificant.

Intermediate24 min read15 sectionsBlood Bank
Section 1 of 150%

Learning Objectives

Getting started

Section 1 of 15

Learning Objectives

Learning Objectives

Section: Learning Objectives

Each objective below describes a competency you will apply at the immunohematology bench, interpretation first, memorization second.

  • Describe Le(a) and Le(b) expression as antigens adsorbed onto red cells from plasma rather than synthesized as integral RBC membrane proteins like Rh
  • Relate common Lewis phenotypes to secretor status at an educational level without requiring full fucosyltransferase genetics mastery
  • Explain why Lewis antibodies are generally considered clinically insignificant for RBC transfusion and how they still create serologic noise