[Reactive arthritis and its etiopathogenic mechanisms]

The reactive arthritis is an important clinical entity, which is under intense scientific investigation particularly in what concerns to the infective agent and the immunological mechanisms involved in its pathogenesis. The infective agents, as well as the antigens and the cellular immune response lead to arthritis after a sequence of events. Some important aspects, such as the genetic predisposition of some individuals, the intracellular life cycle of the bacteria, the mucosal membranes as the site of penetration of the infectious agent, as well as the lipopolysaccharide as the most important component of the membrane, are extensively discussed. The importance of better understanding this disease will end up in the amelioration of therapeutic approach.