Systemic Lupus Erythematosus

Systemic lupus erythematosus is a systemic autoimmune disease with a worldwide distribution. Although both men and women of all age groups can be affected, women outnumber men almost 10 fold and the typical lupus patient is a young woman during her reproductive years. Clinically, lupus is a disease with an unpredictable course involving flares and remissions, where cumulative damage over time significantly interferes with the quality of life and adversely affects organ function. Multiple cells, tissues, and organs can be affected in this disease, and the clinical picture can vary greatly between patients. Indeed, even in the same patient the clinical picture may not be consistent over time. Organ systems most commonly involved in lupus patients include joints, skin and mucous membranes, blood cells, brain, and kidney. Although the prognosis of lupus patients has dramatically improved with the widespread introduction of potent immunosuppressive therapies and better medical management of acute disease exacerbations, a diagnosis of SLE remains associated with an appreciably shortened life span. Moreover, the mortality rates are still significant among patients with active disease. With more lupus patients living with chronic, intermittently active disease, it has become evident that there is significantly accelerated atherosclerotic cardiovascular disease that is insufficiently explained by traditional risk factors. A second major cause of mortality in SLE is infection. Lupus patients have an inherent susceptibility to infections due to their disease. In addition, the major side effect of the large majority of medications currently used for treatment of lupus is immunosuppression, which confers a greatly increased risk for infections with typical and atypical organisms. For this reason, the use of more aggressive approaches is usually restricted to patients with active disease, with lower doses of immunosuppressive treatment being used for chronic maintenance. The universal belief and expectation among investigators and physicians involved in SLE is that a more comprehensive and accurate understanding of the underlying mechanisms of disease will lead to the development of more targeted therapies. Such novel approaches to treatment would presumably result in improved patient response rates, decreased numbers of flares, attenuated cumulative damage, and enhanced preservation of organ function over time. Moreover, even if newer therapies have a similar efficacy profile to medications in current use, the employment of more targeted and specific therapeutic modalities could reasonably result in less unintended side effects. In this special issue, we have gathered contributions from physicians and researchers from North America, South America, Europe, and Asia that highlight several important and/or novel aspects of the molecular pathogenesis, clinical organ involvement, and experimental therapies in this prototypical systemic autoimmune disease.