Systemic lupus erythematosus (SLE or lupus) is a chronic, autoimmune disease that can affect multiple organs such as skin, joints, and any visceral organ.
Incidence varies by country, but can range from 1 to 10 per 100,000 people annually, while prevalence is at 20 to 70 per 100,000 annually (1). Women are more commonly affected than men, with incidence and prevalence rates nearly 10 times that of men. In the United States (US), there is no specific national cost for SLE, but the average hospital charges for diffuse connective tissue diseases, including SLE, was estimated to be about $13.3 billion in 2011.
At presentation, SLE is often mistaken for a myriad of other diseases due to the symptoms of fever, malaise, joint pains, muscle pains and fatigue (2). Differential diagnosis of SLE is challenging, but the presence of anti-nuclear antibodies is the mainstay of diagnositic testing. These antibodies have been shown to react with double stranded DNA (dsDNA), as well as histones. Antibodies to dsDNA are highly specific for SLE, and found in 70% of cases, compared to 0.5% in the population at large (1). These anti-nuclear antibodies are often seen in skin, where they can form band-like deposits in the basement membrane layer of the epidermis, as wells as labeling the nuclei. Other symptoms of SLE include pleurisy and pericarditis (inflammation of membranes around the heart and lungs) (3), which often accelerates other cardiovascular disease, notably atherosclerosis (4). SLE patients often experience muscle and joint pain, possibly associated with ANAs, but generally less debilitating than rheumatoid arthritis (5). SLE can also affect the heart, giving rise to a form of endocarditis, the lungs, where it causes a variety of lung disorders, from pneumonitis to pulmonary hypertension, and the kidneys where lupus nephritis can lead to end=stage kidney failure (6).