The 640 patients with active SLE were attented the Affiliated Hospital of Guangdong Medical College between January 1997 and December 2006. All patients conformed to the diagnostic criteria for SLE published by the American College of Rheumatology in 1982. 2 Of the 640 patients, 567 were female and 73 were male, with a mean age of (28.8¡12.1) years (range: 5-69). Disease duration was between 2 days and 20 years. SLE disease activity index (SLEDAI) was evaluated with a SLEDAI score system in all patients. The patients with SLEDAI $10 were considered to have severely active SLE and were included in the study. Of the 640 patients, SLE occurred for the first time or recurred Copyright ß 2011 CLINICS -This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http:// creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted noncommercial use, distribution, and reproduction in any medium, provided the original work is properly cited. as a result of stopping treatment when their condition improved. Of the patients who had been hospitalized several times as a result of a flare episode with SLEDAI $10, we only recorded the first data. The patients in whom SLEDAI score could not be calculated as a result of incomplete clinical data, infection, or who were living more than 100 km from the city center were excluded from this study.