Abstract
Lyme disease has many different manifestations, including arthritis. There is no evidence that the pathogen Borrelia burgdorferi expresses toxins, so the presence of the organism is insufficient to cause inflammation and disease. Thus, the interaction between the causative pathogen and the many human immune system mechanisms responding to the organism is the apparent cause of inflammation and tissue damage/dysfunction. This review discusses many of the aspects of the relationship between organisms and host responses to summarize the many means by which the immune response can cause the synovitis of Lyme arthritis.