Procalcitonin: Study of its efficacy as a potent biomarker in non-sepsis bacterial infection

Background: The calcitonin hormone plays a crucial role in regulating calcium and phosphorus homeostasis. Moreover, during systemic inflammation, particularly in bacterial infections, procalcitonin production occurs in various tissues, such as the lung, liver, kidney, and adipose tissue. This rise of procalcitonin levels becomes detectable as early as 2 to 4 hours post-stimulation, peaking within 6 to 24 hours. This is why, unlike C-reactive protein (CRP), procalcitonin is considered the earliest and most stable marker, as its concentration is unaffected by neutropenia, immunodeficiency conditions, and the use of nonsteroidal or steroid anti-inflammatory drugs. However, the reports are mainly based on sepsis-induced bacterial infection. Thereby the aim of the present study was to evaluate the procalcitonin test’s ability to discriminate different bacterial (Non- sepsis) etiology in a large population of patients.Materials and Methods: This longitudinal observational study was conducted using clinical and routine laboratory data collected from the Clinical Microbiology Unit of the Narayana Multispeciality Hospital, Barasat, Kolkata, from 2nd August 2022 to 15th January 2023, to evaluate the significance of serum biomarker C reactive protein, total leucocyte count, and procalcitonin test in early detection of bacterial infection.Result: In the present study, it was observed that the prevalence of elevated procalcitonin levels is higher with the gram-negative bacterial infection, especially among Escherichia coli and Klebsiella pneumoniae, in comparison to the gram-positive bacterial infected population.