Antigens of the Ii System on Lymphocytes

USUALLY Ii specificity is assigned to cold agglutinins on the basis of their reactions with the red cells of human adults (adult red cells) and newborn infants (cord red cells). Those which react more strongly with adult red cells are said to detect I antigen and are designated anti-I; those which react more strongly with cord red cells are said to detect i antigen and are designated anti-i^1,2. We have now found that I and i antigens can be easily detected on lymphocytes.