The network of biological processes which protect an organism from diseases is termed as the immune system. The branch of medicine which deals with the study of the diseases which are caused by problems in the immune system is known as clinical immunology. It encompasses the failure, divergent action, and malignant growth of the cellular components of the immune system. The diseases studied within this field can be classified into immunodeficiency and autoimmunity. Immunodeficiency involves the immune system being unable to provide adequate response. Autoimmunity refers to the situation wherein the immune system attacks the body of the host. The book aims to shed light on some of the unexplored aspects of clinical immunology and the recent researches in this field. It elucidates the concepts and innovative models through a case based approach. Those with an interest in this field would find this book helpful.