Systemic lupus erythematosus (SLE) is a chronic disease that is characterized by an undulating course of exacerbations and remissions, and a major determinant of long-term prognosis is organ damage consequent to tissue injury that accompanies disease activity and toxicity of therapy. In this study, we evaluated which patients with SLE will develop an exacerbation and whether factors can be identified to predict the development of an exacerbation. Fifty-seven SLE patients (52 females) were included in this study. The exacerbation of SLE was found in 15 patients (26.3%). A relatively increased incidence of an exacerbation was found in younger SLE patients. An increased percentage of patients who had lupus nephritis at the time of diagnosis of SLE was found in patients with a subsequent exacerbation when compared with that in those without it. Increased incidence of an exacerbation was observed in patients who had decreased number of WBC and platelets, decreased level of C3 and CH50, and the presence positivity of anti-Sm antibodies at the time of the diagnosis. This study suggests that age, renal involvement, and the presence of decreased number of WBC and platelets, decreased level of complements anti-Sm antibodies are predictors of exacerbation
