Final answer:
Autoimmunity can result from hypersensitivity types II and III but not typically from type IV, which is a T-cell mediated reaction involving cells like macrophages and cytotoxic T cells, not antibodies.
Step-by-step explanation:
Autoimmunity can result from all types of hypersensitivities except for type IV. Type IV hypersensitivities are characterized by being T-cell mediated reactions and do not involve antibodies. In autoimmunity, there is a loss of self-tolerance where the body's immune system mistakenly attacks its own tissues. The mechanisms responsible for autoimmune disorders include type II, type III, and occasionally type IV hypersensitivity reactions. The key difference with type IV is that it involves a delayed T-cell-mediated inflammatory reaction, which takes longer to manifest than types I-III hypersensitivities, because it requires activation of antigen-presenting cells and T-cell subsets.
Unlike type III hypersensitivities, which are mediated by immune complexes that lead to inflammation and tissue damage, type IV hypersensitivities involve tissue damage mediated by activated macrophages and cytotoxic T cells. Autoimmune diseases can have mixed symptoms that flare-up and subside, making diagnosis challenging, and often involve complex interactions within the immune system, including various hypersensitivity types.