Microbial-linked diseases--shifting the pathogenic paradigm. 25-26 June 1998, San Diego, USA

This innovative cross-discipline conference brought together an international cohort with widely different backgrounds to address 'hard' infections in a way that is unusual in the modern era. The success of this 'experiment' was reflected by the strong and enthusiastic support from all the attendees present, with the hope that this meeting will be the first of many. The meeting was introduced by a review of the parallel development of a scientific framework within which the clinical pressures of the day must be considered if therapeutic progress is to occur. The simple paradigm of infection driving an antibody response identified as protection, proved of value at the turn of the century when epidemic infectious diseases prevailed. Such a paradigm is hopelessly inadequate to cope with the new pressures of degenerative disease, neoplasia, and chronic inflammatory disease, which now dominate the clinical agenda and with which 'infection' is tenuously linked. The excitement of the discovery that many of our major health challenges are outcomes of interaction between microbes and the host response, was the theme of this meeting. Subtle variations in microbial pressure or host response, have focused attention on genetic background, compartmentalized response and microbe distribution, persistence of antigen, 'escape' forms of the microbe, inappropriate host responses which damage through hypersensitivity mechanisms, and perpetuation of disease through the triggering of autocrine or autoimmune mechanisms. Two particularly important factors are the role of dysfunctional T-lymphocytes and variable outcomes influenced by the 'dose-response' curve, which can determine up- or downregulation of the immune response. The various presentations given provided excellent models of these general principles, and will be discussed in this context.