Immunopathology is a branch of medicine, which deals with the immune responses associated with diseases. The immune response of a body can harm the organism itself, due to a mismatch between pathogen and host species, or when an infection is caused by an animal pathogen. When a foreign antigen enters the body, there can either be an antigen specific or antigen nonspecific response to it. Hypersensitivity, autoimmunity and immunodeficiency are abnormal immune responses of the human body. AIDS, HIV and leukemia can lead to immunodeficiency. The treatment of all such immune conditions is under the scope of clinical immunology. This book elucidates the current progress in the field of immunopathology in a multidisciplinary manner. It provides significant information of this discipline to help develop a good understanding of the working of the human immune system and immune responses. It is a vital reference tool for academicians, physicians and students alike.