<prompt> Antibody in cold agglutin disease isIgAIgGIgEIgM  <response>: Cold agglutinin disease CAD: This designation is used for a form of chronic AIHA that usually affects the elderly. First, the term cold refers to the fact that the autoantibody involved reacts with red cells poorly or not at all at 37degC, whereas it reacts strongly at lower temperatures. As a result, hemolysis is more prominent the more the body is exposed to the cold. The antibody is usually IgM; usually, it has an anti-I specificity the I antigen is present on the red cells of almost everybodyHarrison 19e pg: 659 