Evidence that the low-incidence red cell antigens Rla and Lsa are identical

Area of Science:

• Immunology
• Transfusion Medicine
• Genetics

Background:

• Red blood cell antigens play a crucial role in blood transfusion compatibility and are important in diagnosing certain medical conditions.
• Low-incidence antigens, present in a small percentage of the population, can cause significant challenges in blood matching.
• The Ls(a+) and Rl(a+) antigens have been historically considered separate entities, necessitating clear identification.

Purpose of the Study:

• To determine if the low-incidence red blood cell antigens Ls(a+) and Rl(a+) are identical.
• To provide clarity in red blood cell antigen classification and improve transfusion practices.

Main Methods:

• Testing of Ls(a+) and Rl(a+) red blood cells using a panel of antisera with antibodies to low-incidence antigens.
• Performing adsorption and elution tests to confirm serological findings.
• Utilizing immunoblotting with antibodies to glycophorin C and glycophorin D to investigate the molecular basis of the antigens.

Main Results:

• Serological testing with numerous antisera indicated that Ls(a+) and Rl(a+) antigens are identical.
• Adsorption and elution tests confirmed the identity of these two antigens.
• Immunoblotting results supported the conclusion by showing reactivity with antibodies to glycophorin C and glycophorin D.

Conclusions:

• The Ls(a+) and Rl(a+) red blood cell antigens are identical.
• This finding has implications for red blood cell typing, antibody screening, and transfusion management, particularly in populations where these antigens are present.