The emerging concept of pathogenic natural autoantibodies.

Natural autoantibodies (NAA) are self-reacting antibodies found in the serum. NAA do not require antigenic or mitogenic stimuli for their synthesis. These low affinity antibodies are found in the sera of normal healthy subjects and animals and are thought to constitute part of the innate immunity by providing a first line of defense against foreign invading pathogens. In this paper we summarize the recently accumulated data which points to the pathogenic potential of NAA, challenging the paradigm of nonharmful antibodies.