Causes of fever in systemic lupus erythematosus: a retrospective study of 487 hospitalized patients / 中华风湿病学杂志

ABSTRACT

Objective To investigate the causes of fever in systemic lupus erythematosas (SLE)patients and identify the characteristics of the fever caused by SLE fever infection after steroid therapy.Methods From January 2002 to May 2007, 487 SLE hospitalized patients with fever were admitted and their data were retrospectively studied. The clinical manifestations and medications were followed up. A case control design was carried out to identify the differences between fever caused by lupus and infection. Results Among all the 487 patients, 265 had infection, 206 had fever that was caused by SLE per se, fever caused by both lupus and concurrent infection was confirmed in 8 patients, malignancy and miscellaneous were the causes of fever in 4 respectively. The most common sites of infection were respiratory tract (61.3%), skin and mucosa (10.9%) and central nervous system (9.1%). The main microorganisms isolated were bacteria (77.4%), fungi (13.5%) and virus (7.8%). Prednisene ≤ 100 mg/d could suppress fever caused by lupus in 81.0% patients, usually within 1 to 5 days. In the case control study, lower C3, C4 and CH50, anemia, lymphocytosis, higher immunoglobulin levels, elevated anti-dsDNA antibodies, elevated anti-nuclear antibodies and higher SLEDA1 score were associated with SLE fever. Long SLE duration, old age, elevated CRP levels,leukocytosis, neutrophilia, high accumulated doses of prednisone and ever use of immunosuppressive medications were factors associated with infection. Conclusion The fever of in-patient SLE patients is mainly caused by infections and disease flare. Moderate dose of steroid therapy is effective to control the fever caused by lupus flare. The fever caused by SLE has different clinical features and laboratory results when compared to that caused by infection although both responses to steroid therapy.