Is serum procalcitonin measurement a useful addition to a rheumatologist's repertoire? A review of its diagnostic role in systemic inflammatory diseases and joint infections.

Early differentiation between infection and aseptic inflammation is difficult and is a challenge often faced in the rheumatology practice. Procalcitonin (PCT) is a biomarker that is preferentially induced in patients with bacterial infections, and a growing body of evidence supports its use for improving diagnosis of bacterial infections and guiding antibiotic therapy. In this article, we review the evidence for the use of PCT measurement in rheumatology practice. Several studies have examined the use of PCT to assist in the differentiation between septic and non-septic arthritis in patients with an inflamed joint and found it to be a sensitive and specific marker of infection. A number of studies in patients with diverse inflammatory rheumatic diseases have provided useful information regarding the usefulness of PCT in these patients. In summary, PCT when used in the appropriate clinical setting can be a useful adjunct to currently available laboratory infection markers, though further studies are warranted. Furthermore, PCT results should be interpreted in parallel with the clinical assessment.