“…However, the usefulness of procalcitonin to identify systemic bacterial infections in patients with SLE remains controversial. Although several studies have examined procalcitonin in SLE patients with infections, those studies have been limited by small numbers of patients with infection, analysis of multiple serum samples, variability of patient characteristics, or with the inclusion of patients with other systemic autoimmune disease 16,17,25,28,29,30 . One study demonstrated that SLE patients with bacterial or fungal infections (n = 9) had significantly higher procalcitonin levels than those with viral infections (n = 3) or lupus flares (n = 7) and a normal control group (n = 11) 16 .…”