In the past few years, there has been considerable progress in the identification and characterization of B and T cell idiotypes associated with autoimmunity1,2. The identification of human VHand VLfamilies and the more widely available techniques for sequencing the genes encoding these regions is beginning to help elucidate the structural basis of idiotypy. Awareness of these structures has stimulated experiments designed to suppress, specifically, aberrant immune responses. Such therapy is an attractive prospect but its clinical utility remains unproved. While the concept of the idiotype network as originally defined by Jerne2has been modified since it was first proposed over 20 years ago, we share the view of Coutinho3that its manipulation may well contribute solutions to autoimmune disease. In this article, we will outline some of the more recently described links between idiotypes and certain autoimmune conditions and examine the possibilities for the management of these disorders by modulation with antibodies on peptides targeted to these structures.