High Serum Procalcitonin: Interpret with Caution Fahmi Yousef Khan * Department of Medicine, Hamad General Hospital, P.O. Box 3050, Doha, Qatar * Corresponding author: Khan FY, Consultant, Department of Medicine, Hamad General Hospital, P.O. Box: 3050, Doha, Qatar, Tel: 0974-55275989; Fax: 0974-44321276; E-mail: fakhanqal@gmail.com Received date: April 27, 2017; Accepted date: April 28, 2017; Published date: April 29, 2017 Copyright: © 2017 Khan. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Citation: Khan FY (2017) High Serum Procalcitonin: Interpret with Caution. Clin Microbiol 6: e141. doi:10.4172/2327-5073.1000e141 Editorial Serum procalcitonin (PCT), which is usually produced in thyroid C- cells, is a precursor of calcitonin. In general, PCT is not released into the blood and, therefore, cannot be detected in healthy individuals [1]. However, serum procalcitonin increased signifcantly in response to stimulation by bacterial infections showing a favorable pharmacokinetic profle as clinical markers for bacterial infection. Consequently PCT has been used increasingly to identify systemic bacterial infections since mid of 1990 [2]. Moreover, a growing body of evidence has suggested that high serum PCT is a useful biochemical marker for discriminating between sepsis and some non-infectious causes of systemic infammatory response syndrome and is a valuable prognostic marker [3]. A rise or no change in procalcitonin level in second week was a good predictor of outcome suggesting intensifcation of antibiotic therapy [2]. Recent randomized clinical trials showed that serum PCT level can be used to guide antibiotic therapy in patients with severe sepsis; it resulted in a signifcant reduction of antibiotic therapy and similar medical outcomes. In addition, the length of intensive care treatment in the PCT-guided group was signifcantly shorter than that in the control group [4,5]. In febrile neutropenia, PCT was found to be useful in diagnosing bacterial infection in these patients [6]. Noteworthy, most of the above mentioned clinical implications of PCT were derived from observational studies. Despite these growing evidences, elevation of serum PCT continues to challenge the diagnostic acumen of physicians as more recent studies have produced conficting results [7]. Additionally, usefulness of PCT measurement in sepsis confrmation has some limitations such as false-positive and false-negative results; some patients with sepsis may not have increased PCT levels while others with high serum PCT may not have sepsis. According to available evidences, elevation in serum PCT levels in the absence of a bacterial infection can be seen in situations of massive stress, for example afer severe trauma and surgery, in patients afer cardiac shock or some autoimmune diseases such as Kawasaki disease and adult-onset Still’s disease [2]. Procalcitonin also may be elevated in medullary thyroid cancer, small cell lung cancer, postoperative complications, cirrhosis, pancreatitis, ischemic bowel and paraneoplastic syndrome [8,9]. Conversely, high PCT levels may not be found in patients with mycoplasma community acquired pneumonia and in patients who received antibiotic pre- treatment [5]. Second limitation is that there is no single cut-of range of PCT levels for defning sepsis. While for some types of infections and clinical settings optimal PCT cut-ofs have been established, optimal cut-of levels for other infections have not been established yet. Tus, the clinical beneft and safety of using serum PCT level in diferent clinical settings remains undefned. Tird limitation is related to the efcacy of PCT level monitoring as guidance for antibiotic therapy. Tis property has been tested for certain infections such as respiratory tract infections and is not applicable to other infections. In view of available evidences it is too early to come up with fnal conclusions on the efcacy of PCT in diagnosing sepsis or other related situations. Terefore, high serum PCT level should be interpreted with caution; physicians should incorporate this biomarker with medical context of the disease and other tests related to infection when diagnosing sepsis. References 1. Christ-Crain M, Muller B (2005) Procalcitonin in bacterial infections-- hype, hope, more or less? Swiss Med Wkly 135: 354-360. 2. Lee H (2013) Procalcitonin as a biomarker of infectious diseases. Korean J Intern Med 28: 285-291. 3. Wacker C, Prkno A, Brunkhorst FM, Schlattmann P (2013) Procalcitonin as a diagnostic marker for sepsis: a systematic review and meta-analysis. Lancet Infect Dis 13: 426-435. 4. Bouadma L, Luyt CE, Tubach F, Cracco C, Alvarez A, et al. (2010) Use of procalcitonin to reduce patients’ exposure to antibiotics in intensive care units (PRORATA trial): a multicentre randomised controlled trial. Lancet 375: 463-474. 5. Schuetz P, Albrich W, Mueller B (2011) Procalcitonin for diagnosis of infection and guide to antibiotic decisions: past, present and future. BMC Med 9: 107. 6. Christ-Crain M, Stolz D, Bingisser R, Müller C, Miedinger D, et al. (2006) Procalcitonin guidance of antibiotic therapy in community-acquired pneumonia: a randomized trial. Am J Respir Crit Care Med 174: 84-93. 7. Liu Y, Hou JH, Li Q, Chen KJ, Wang SN, et al. (2016) Biomarkers for diagnosis of sepsis in patients with systemic infammatory response syndrome: a systematic review and meta-analysis. Springerplus 5: 2091. 8. Becker KL, Snider R, Nylen ES (2008) Procalcitonin assay in systemic infammation, infection, and sepsis: clinical utility and limitations. Crit Care Med 36: 941-952. 9. Limper M, de Kruif MD, Duits AJ, Brandjes DP, van Gorp EC (2010) Te diagnostic role of procalcitonin and other biomarkers in discriminating infectious from noninfectious fever. J Infect 60: 409-416. Clinical Microbiology: Open Access Khan, Clin Microbiol 2017, 6:2 DOI: 10.4172/2327-5073.1000e141 Editorial Open Access Clin Microbiol, an open access journal ISSN:2327-5073 Volume 6 • Issue 2 • 1000e141 C l i n i c a l M i c r o b i o l o g y : O p e n A c c es s ISSN: 2327-5073