(Taken from the application): Support is requested for a two day conference entitled """"""""Ankylosing Spondylitis Research: HLA-B27 and Beyond,"""""""" to be held on September 1 and 2, 1998, on the NIH campus in Bethesda. The purpose of this meeting is bring together a group of basic and clinical scientists from a variety of disciplines to critically evaluate ongoing research related to AS and to identify potential new avenues of research into the pathogenesis of this disorder. AS is a relatively common, chronic, painful, deforming, inflammatory rheumatic disease that affects the axial skeleton and, to a variable extent, other articular and nonarticular sites, with the onset at a median age of 23 years. Its pathogenesis is poorly understood, and current therapy inadequately prevents deformity and disability in many patients. In recent decades, investigation of AS has focused productively on clinical classification, epidemiology and genetics, and less productively on potential bacterial triggers. Relatively little investigation has been devoted to the cellular and molecular pathogenesis of the disease, particularly with regard to the chronic changes in the axial skeleton. The overall goal of this conference will be to galvanize AS research by providing constructive critical input for ongoing research and by attracting ideas and methodology from disciplines that could productively be applied to AS research but currently are not. Both approaches will take advantage of the attendance of NIH investigators. Four half day sessions are planned: (i) clinical, radiographic, and genetic aspects of AS; (ii) immunology and immunopathogenesis; (iii) bone, cartilage, and connective tissue; (iv) inflammatory bowel disease, bacteria, and mucosal immunology. Sessions 1 and 2 will consist predominantly of presentations by investigators currently engaged in AS research, and these sessions will be particularly valuable for gaining critical comments from basic immunologists and other investigators from NIH. Sessions 3 and 4 will consist predominantly of investigators working, respectively, on the molecular and cell biology of the extracellular matrix, and on the immunology and microbiology of the intestine and inflammatory bowel disease. These sessions will also benefit from the participation of NIH investigators. The format of the meeting is being organized to maximize discussion, to foster new collaborations, and to attract established and new investigators to work on problems related to AS.