The prognosis of patients with SLE has improved due to immunosuppressive therapy. The therapy together with immunological abnormalities associated with SLE leads to an increased risk of severe infections.
Differentiation between flare of a disease and infectious complications is difficult. Procalcitonin is a biomarker which has been used mainly in patients in critical condition for the differential diagnosis of systemic inflammatory response syndrome and sepsis.
The sensitivity and specificity of increased procalcitonin serum levels in case of an infection varies in different studies. This report presents a basic review of the knowledge on procalcitonin, and targets its potential use in rheumatology.
Since the level of procalcitonin increases rapidly with a systemic bacterial or mycotic infection, and is not significantly affected by an autoimmune process or glucocorticoid therapy, it can be peculated, that procalcitonin could serve as a suitable indicator in the dif. dg. of these two situations.