PCT

This test measures the amount of procalcitonin in the blood. Procalcitonin is made during the process of producing the thyroid hormone calcitonin. It is normally produced by special cells in the thyroid gland called C-cells and is present in low levels in the blood. However, it may also be made by other cells in the body when stimulated by certain disease processes, in particular whole body bacterial infection (systemic bacterial infection or sepsis) as opposed to just local bacterial infections. Other reasons for increased procalcitonin include infection from other causes, tissue damage due to events such as trauma, surgery, pancreatitis, burns, heart attack; and rapid and severe organ (kidney, heart, lung etc) transplant rejection.

Levels of procalcitonin in the blood increase rapidly and to high concentrations when a person has sepsis. They are not as particularly increased when a person has a viral infection or other illnesses which may have the same or similar symptoms as sepsis. Difference in stimulous gives procalcitonin the potential to be used to help detect severe bacterial infection at an early stage and to be able to distinguish between a bacterial infection and another cause of a serious illness.