Emerging evidence for serum procalcitonin estimation at point-of-care and advancement in quantitative sensing strategies over the past decade

Abstract

Abstract The menace of antibiotic resistance is on the rise, and one critical reason for that is the inappropriate use of antibiotics. Detection, severity assessment, and differentiation of bacterial infection from other causes of similar symptoms remain the key to guide antibiotic therapy. Unlike other acute phase reactants, procalcitonin (PCT) has evolved as a promising biomarker that can help distinguish between bacterial infections and other infections caused by virus, fungus or any other inflammatory condition. In the normal physiological state, it is produced mainly from parafollicular C cells of the thyroid gland and in minute quantities from the neuroendocrine cells of the lungs and the intestine and gets converted to calcitonin, the calcium regulating hormone. It is produced from extra thyroid tissues during bacterial infections, mediated by interleukin 6 (IL-6) and tumour necrosis factor-alpha (TNF-α). PCT is an excellent biomarker for sepsis detection in an institutional setting and has been included in many diagnostic algorithms and scoring systems. Apart from that, it is used for the monitoring of response and discontinuation time of antimicrobial agents. Recent evidence supports the use of procalcitonin estimation in primary care settings and monitoring of COVID-19 cases also. A low cost, rapid, quantitative point of care sensor with desired sensitivity is needed for that to be possible. Several sensitive optical and electrochemical biosensors have been designed to quantify serum PCT. Some have been translated to laboratory settings, but not much progress has happened in terms of rapid point-of-care detection, which is essential considering the clinical relevance. In this article, the progress in the last decade has been reviewed, both in terms of clinical evidence and the sensor development for procalcitonin. Discussion regarding possible advancements has also been carried out.