Natural antibody 1983 reported that 2 cases of anti-Le were found in blood donors, both of which belonged to IgM. One red blood cell blood group is A 1Le(a-b-), and the salivary substances A and H, while the other red blood cell blood group is AB, Le(a-b-), and the salivary substances A and B ... both cases do not secrete Le and Le substances. Lewis antibody mostly exists naturally and belongs to IgM, so it generally does not cause hemolytic disease of newborn. However, there are reports in foreign literature that anti-Le causes hemolytic disease of newborn.

Immune antibody Lewis antibody can produce hemolytic transfusion reaction. Zhou Xingdi reported anti-Le, Yu Xinfa reported anti-Le+ anti-E, and another case was reported on 1999.