The Lewis system antigens are not an integral part of the red cell membrane and are produced by tissue cells and found primarily in plasma and watery secretions. Red cells acquire Lewis antigens by absorption from surrounding plasma. The amount of Lewis antigen expressed on a cell can vary with the cell’s ABO phenotype. Anti-Lea and Anti-Leb have not been associated with Haemolytic Disease of the Newborn, but examples of Anti-Lea have caused Haemolytic Transfusion Reactions.

The reagents will cause agglutination (clumping) of test red cells, that carry the corresponding Lewis antigen, after centrifugation. No agglutination generally indicates the absence of the corresponding Lewis antigen.
Lorne Monoclonal Anti-Lea blood grouping reagent contains human monoclonal IgM antibodies, diluted in a phosphate buffer containing sodium chloride, EDTA, bovine albumin and macromolecular potentiators.