Lewis antibodies are most commonly which class of antibodies?

Lewis antibodies are primarily of the IgM class. This is important because IgM antibodies typically respond to non-self antigens, such as those found on red blood cells, and are often involved in the initial immune response. In the context of Lewis antibodies, they are naturally occurring antibodies that can develop in individuals who do not possess Lewis antigens on their red blood cells. This means that when a person who does not have the Lewis antigens is exposed to blood containing these antigens, they may produce IgM antibodies against them.

In addition to being involved in transfusion reactions, IgM antibodies also activate complement, which can lead to hemolysis. The presence of IgM Lewis antibodies is significant in blood banking and transfusion medicine, as they can cause unexpected laboratory reactions and have implications for compatibility testing.

Other classes of antibodies, such as IgA, IgE, and IgD, do not primarily relate to the formation of Lewis antibodies in the same way. IgA is predominantly found in mucosal areas and secretions, IgE is involved in allergic reactions and responses to parasites, and IgD is largely a receptor on B cells and has not been associated with the same type of interactions as the Lewis antibodies. Thus, the classification