Which immune molecule is most commonly associated with immuno-mediated hemolytic anemia (IMHA)?

Immuno-mediated hemolytic anemia (IMHA) is primarily associated with the presence of IgG antibodies. These antibodies play a crucial role in the immune response by binding to red blood cells (RBCs) that are perceived as foreign or damaged. When IgG binds to the surface of these RBCs, it marks them for destruction by phagocytic cells in the spleen and liver, leading to hemolysis.

In the context of IMHA, IgG is the most relevant antibody because it is known for its ability to opsonize cells, enhancing their clearance from circulation. IgG can activate the complement system and induce antibody-dependent cellular cytotoxicity, further promoting the destruction of the affected red blood cells.

Other antibodies, such as IgM, are less commonly associated with IMHA in dogs and cats. While IgM can also bind to RBCs and activate complement, it is more often involved in acute, intravascular hemolysis. IgA and IgE generally have different roles in the immune system, with IgA being predominantly involved in mucosal immunity and IgE being associated with allergic responses and parasitic infections.

Recognizing the critical role of IgG in the pathophysiology of IMHA