Pernicious Anemia: Type II Hypersensitivity Explained

Pernicious anemia is a non-cytotoxic hypersensitivity reaction, specifically a type II hypersensitivity reaction.

In type II hypersensitivity reactions, antibodies are directed against cell-surface antigens, leading to complement activation and cell lysis. This is in contrast to cytotoxic reactions, where antibodies are directly cytotoxic to target cells, such as in type I hypersensitivity reactions (mediated by IgE antibodies and mast cells).