Test Code PROCALCITONIN PROCALCITONIN
Department
Chemistry
Specimen Type
Plasma or Serum
Method
Chemiluminescent Immunoassay
Container
Lithium heparin (green-top) or No additive with gel (gold top)
Standard Volume
7ml
Minimum Volume
2ml
Pediatric Volume
2 Microtainers (Gold or Green)
Ship Temperature
Room Temperature
Stability Refrigerated
48 hours
Stability Room Temp
16 hours
Stability Frozen
75 days
CPT Code
84145
Days Test Set Up
Monday through Sunday
Group Components
PROCALCITONIN
Clinical Information
Procalcitonin is the prohormone of the hormone calcitonin, but procalcitonin and calcitonin are distinct proteins. Calcitonin is produced exclusively by C-cells of the thyroid gland in response to hormonal stimulis, whereas procalcitonin can be produced by several cell types and many organs in response to pro-inflammatory stimuli, in particular by bacerial products.
In healthy people, plasma procalcitonin levels are found to be below 0.1 ng/ml. Procalcitonin levels rise rapidly (within 6 – 12 hours) after a bacterial infectious insult with systemic consequences. Early after multiple traumas, major surgery, severe burns, or in neonates procalcitonin levels can be elevated independently of an infectious process, but the return to baseline occurs rapidly. Viral infections, bacterial colonization, localized infections, allergice disorders, autoimmune diseases, and transplant rejection do not usually induce a significant procalcitonin response.
Test Use
The procalcitonin test is intended for use in conjunction with other laboratory findings and clinical assessments to aid i the risk assessment of critically ill patients on their first day of admission for progression to severe sepsis and septic shock.
Cautions
Increased levels may not always be related to sytemic infection. These conditions include, but are not limited to: the first days of major trauma, treatment with OKT3 antibodies, interleukins, and TNF-alpha and other drugs stimulating the release of pro-inflammatory cytokines, patients with medullary C-cell carcinoma, small cell lung carcinoma, or bronchial carcinoid, and patients with prolonged or severe cardiogenic shock, prolonged sever organ perfusion anomalies, Child-Pugh Class C liver disease, and peritoneal dialysis treatment.
Interpretation
Procalcitonin levels less than 0.5 ng/ml on the first day of ICU admission present a low risk for progression to severe sepsis and/or shock. Levels this low do not preclude an infection, because localized infections (without systemic signs) may also be associated with low levels. If the PCT measurement is done very early after the systemic infections has started, these values may still be low.
Procalcitonin levels greater than 2 ng.ml on the first day of ICU admission represent a high risk for progression to severe sepsis and/or septic shock.
As various non-infectious conditions are known to induce PCT as well, levels between 0.5 and 2 ng/ml should be reviewed carefully to take into account the specific background and condition of the individual patient.