Procalcitonin as a Biomarker for Predicting Infectious Diseases

Abstract

Introduction: It's still difficult to diagnose bacterial and fungal infections in a timely manner. Most often, there is a paucity of trustworthy clinical and microbiological criteria from accessible specimens that may be used to identify bacterial infections and rule out other infections.

Objectives: The objective of the study was to diagnose bacterial and fungal infections based on Procalcitonin level.

Methods: PCT levels were measured in sera using the automatic analyzer VIDAS B.R.A.H.M.S PCT assay. The lower limit of detection of the assay was 0.05 ng/ml and the functional assay sensitivity was 0.09 ng/ml. For each sample, an aliquot of 5 to 10 ml whole blood was inoculated into BACTEC aerobic and anaerobic bottles. The bottles were incubated for 5 days. Identification of microorganisms was performed with the VITEK-2 system.

Results: The main findings of this study are that, in patients with suspected sepsis, the PCT mean value of 48.12 ng/ml could be of help in predicting an infection caused by Gram-negatives, the mean value of 33.05 ng/ml could be of help in predicting an infection caused by Gram-positives, and the mean value of 11.59 ng/ml could be of help in predicting an infection caused by Fungi. In this study, the value of PCT for patients infected with Fungi did not exceed 50 ng/ml, the value of PCT for patients infected with Gram Positive bacteria did not exceed 100 ng/ml and in the case of Gram Negative, the value of PCT reached up to 200 ng/ml which is the maximum detection level.

Conclusions: This study suggests that PCT may be of value in distinguishing Gram Negative from Gram Positive and fungal bloodstream infections. Nevertheless, its utility in predicting different microorganisms needs to be assessed in further studies.