Inflammation, immunity, and Alzheimer's disease.

Few topics in the field of Alzheimer's disease (AD) research have brought about the level of excitement and interest as the role of inflammation and immunity in the pathobiology and treatment of the disease. In this special issue of the journal, experts in the field give their views on how inflammatory processes and the immune system intersect- at both etiological and treatment levels- with disease biology. Collectively, nearly three decades of work are covered in this special issue, beginning with the first epidemiologic studies that showed an inverse risk relationship between AD and use of non-steroidal anti-inflammatory drugs, and ending with "immunotherapy" approaches and recent studies examining the roles of innate immune cells including microglia and peripheral mononuclear phagocytes in AD. Despite considerable work in this area, many important questions remain concerning the nature and timing of immune/inflammatory responses in the context of AD, and at what point and how to therapeutically intervene.