Procalcitonin and C-reactive protein as markers of infection in systemic lupus erythematosus: the controversy continues

Objective: The objective of this paper is to investigate the utility of serum procalcitonin (PCT) and C-reactive protein (CRP) as markers of infection in systemic lupus erythematosus (SLE) patients. Patients and methods: Sixty-nine SLE patients with symptoms and signs of infection proved by culture and/or a favorable response to antibiotics and 69 SLE patients without infection were included. Serum PCT and plasma high-sensitivity CRP were assessed by an enzyme-linked immunosorbent assay. Results: SLE patients with infection had a significantly higher level of CRP than those without infection ((median (IQR) 104.5 (25.5–100.9) and 10.3 (5.4–23.1) mg/l, respectively), p<0.001). Conclusion: Serum PCT could not differentiate SLE patients with or without bacterial infection in this study, while the utility of CRP as a marker of infection has been confirmed.