Autoimmune neurologic diseases
Introduction: Differentiating systemic lupus erythematosus (SLE) activity from infections in febrile patients is difficult because of similar initial clinical presentation. The aim of this study is to evaluate the usefulness of pentraxin 3 (a protein released by a response to primary inflammatory signals, such as TLRs) for differentiating infections from activity in SLE patients admitted with a systemic inflammatory response (SIRS). Methods: Patients with SLE and SIRS admitted to the emergency room were included in this study. Measurements of serum Pentraxin 3 were performed by an enzyme-linked immunosorbent assay (ELISA) using a commercially available kit (Abcam-ab21570). Infection was considered present when positive cultures and/or polymerase chain reaction were obtained. Mann-Whitney U test and ROC curves were used to evaluate the pentraxin 3 performance. Results: Twenty-four patients were admitted, 19 women (79%), mean age 33,5 ± 13.7 years. Infectious disease was confirmed in 10 cases. Markers for SLE activity including anti-DNA titers by ELISA (p=0.04) and complement were used for differentiating SLE flares from infection. On the contrary, increased pentraxin 3 levels were observed in infected SLE patients (35357 pg/mL, IQR: 12839-145625) compared to flares (median: 8321 pg/mL, IQR: 3678-36696 pg/mL), p=0,03. Conclusions: High Pentraxin levels are useful to differentiate infections from activity in SLE patients.