Procalcitonin is not produced by circulating blood cells

Area of Science:

• Immunology
• Biochemistry

Background:

• Procalcitonin (ProCT) is a recognized biomarker for bacterial infections, predicting disease severity and antibiotic treatment effectiveness.
• The precise cellular mechanisms governing ProCT synthesis remain incompletely understood.
• Investigating ProCT production by peripheral blood mononuclear cells (PBMCs) is crucial for clarifying its clinical utility.

Purpose of the Study:

• To investigate the potential for peripheral blood mononuclear cells (PBMCs) to produce procalcitonin (ProCT) in response to inflammatory stimuli.
• To determine if ProCT production by PBMCs mirrors that of other sepsis-related cytokines.

Main Methods:

• A whole blood model was utilized, stimulating samples from 14 healthy volunteers with lipopolysaccharide (LPS) at 10 µg/ml.
• Levels of early cytokines (TNF-alpha, IL1-beta) and late cytokines (IL-6, IL-8) were measured.
• Experiments included assessments for nitric oxide production and intracellular ProCT detection via cell lysis and flow cytometry.

Main Results:

• LPS stimulation induced significant production of TNF-alpha, IL1-beta, IL-6, and IL-8.
• No detectable Procalcitonin (ProCT) was found in the stimulated whole blood samples.
• Additional assays for nitric oxide and intracellular ProCT yielded negative results.

Conclusions:

• Under the tested conditions, peripheral blood mononuclear cells (PBMCs) did not produce Procalcitonin (ProCT) in response to LPS stimulation.
• These findings suggest that PBMCs may not be a primary source of ProCT in this experimental model.
• Further research is required to elucidate the cellular origin of ProCT and enhance its clinical applicability.