- Objective: To review the recent advances in clinical and experimental research in systemic lupus erythematosus (SLE). Methods: Review of the 5th International Congress of SLE that took place inCancun, Mexico, on April 20–25, 1998. Results: The main topics presented at the conference are summarized. These include new findings about the genetics of SLE due to fine mapping of the patients' genes and lupus mouse models, the nucleosome as a major autoantigen in SLE, serving as an immunogen for pathogenic T helper and B cells and contributing to the development of lupus nephritis, abnormalities of apoptosis as a cause of SLE, and apoptotic mechanisms as a cause of autoimmunization. Other topics included the pathophysiologic role of anti-endothelial cell antibodies in lupus with central nervous system involvement, vasculitis, the thrombotic diathesis associated with the antiphospholipid syndrome, induction of endothelial cell apoptosis and its regulation by the idiotypic network, the penetration of antinuclear antibodies to the cytoplasm and nucleus and the subsequent interaction with cellular organelles, and new aspects in the antiphospholipid syndrome, including animal models of the disease and the importance of antibodies to beta-2-glycoprotein-I and prothrombin. Advances in the clinical aspects of SLE included clinical manifestations, diagnosis, pregnancy and neonatal SLE, infections, hormones, and treatment. Additionally, four “Lectures of A Lifetime,” entitled (1) What causes lupus? (2) From natural autoimmunity to autoimmune disease; (3) The idiotypic network and SLE; and (4) Late-stage morbidity and mortality in SLE-the role of accelerated atherosclerosis were presented. Conclusions: Recent advances provide new insights into the pathogenesis of SLE, as well as hope for novel therapeutic modalities and diagnostic measures. These offer the possibility of improving life quality and decreasing mortality from the disease and its complications.