Lupus: the new epidemic.

Is systemic lupus erythematosus (SLE) is occurring more frequently now than in decades past? Despite improvements in the identification of patients with SLE, the development of new classification criteria, and the recognition of several biomarkers used alone or in combination, the diagnosis of SLE is still a challenge for clinicians, in particular early in the course of the disease, which makes the recognition of secular trends difficult to ascertain. Lacking a uniform definition of preclinical lupus or incomplete lupus, it is difficult to predict accurately which patients would go on to develop SLE. We will briefly review the classification criteria, early or preclinical SLE, the epidemiology of SLE, antinuclear antibodies-negative SLE, and biomarkers of the disease.