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25166 Procalcitonin, Serum

Procalcitonin, Serum
Test Code: PCT
Specimen Requirements
 
 
 
Fasting Required Specimen Type Preferred Container/Tube Acceptable Container/Tube Specimen Volume Specimen Minimum Volume
(allows for 1 repeat)
Pediatric Minimum Volume
(no repeat)
​No Serum​Serum Separator Tube (SST)​Red Top Tube (RTT)0.5 mL​
Collection Processing Instructions

Separate serum from the blood within 60 minutes of venipuncture. Serum specimen must be clear and free of red cells, particulate matter including fibrins which interferes with the assay.
Specimens containing free red cells, particulate matter including fibrins should be re-centrifuged. Frozen specimens should be brought to room temperature and re-centrifuged to get a clear specimen.

Outreach specimens should be sent frozen. Three freeze and thaw cycles are acceptable.​

Specimen Stability Information
Specimen Type Temperature Time
Serum​ ​ Refrigerate​ < 48 hours​​
Frozen at -20 deg Celsius​

> 48 hours​

Stable up to 6 months

Rejection Criteria
Grossly hemolyzed​
Grossly lipemic​
Grossly icteric​
Greater than three freeze/thaw cycles
Performing Laboratory Information
Performing Location Day(s) Test Performed Analytical Time Methodology/Instrumentation
Diagnostic and Treatment Center​ ​Monday through Sunday ​Less than 2 hours ​Enzyme Immunoassay (EIA) bioMerieux​
​Eau Claire ​Monday through Sunday ​Less than 2 hours ​Enzyme Immunoassay (EIA) bioMerieux​
​Flambeau ​Monday through Sunday ​Less than 2 hours ​Enzyme Immunoassay (EIA) bioMerieux​
Marshfield​ Monday through Sunday​ Less than 2 hours​ Enzyme Immunoassay (EIA) bioMerieux​
​Neillsville​Monday through Sunday​Less than 2 hours​Enzyme Immunoassay (EIA) bioMerieux​
​Minocqua​Monday through Sunday​Less than 2 hours​Enzyme Immunoassay (EIA) bioMerieux
Test Information

​Procalcitonin (PCT), a prohormone of calcitonin, is secreted by a variety of cell types in response to proinflammatory stimulation, specifically when bacterial in nature. Detection and monitoring of elevated PCT levels is thus useful in the setting of significant bacterial infections such as bacterial sepsis and pneumonia. This quantitative test is cleared by the FDA as an aid in the risk assessment of critically ill patients on their first day of ICU admission for progression to bacterial severe sepsis and septic shock. Published studies have also found the PCT assay to be useful in the diagnosis of other severe bacterial infections.

The interpretation of a PCT level depends on the nature of the suspected bacterial infection, and must be made in the context of clinical signs and symptoms and the results of other diagnostic studies. Generally speaking, a PCT level of < 0.10ng/mL confidently rules out a significant local or systemic bacterial infection in patients >72 hours in age, while a value >2.00ng/mL is highly supportive of bacterial sepsis and/or septic shock. Depending on the circumstances, a PCT value >0.50ng/mL is supportive of a significant bacterial infection when consistent with clinical signs and other diagnostic studies. (See below for specific interpretations.*)

The interpretation of neonatal PCT levels is more complex, since PCT levels in healthy neonates is low at birth, rises as much as 20-fold by 24 hours of age, and then drops into the adult reference range by 72 hours of age.
(See graph: Procalcitonin (PCT) Levels in the Neonate)

Nevertheless, neonatal PCT levels predictably rise above the baseline in response to severe bacterial infections much as they do in older patients.
 
Successful antibiotic therapy leads to a drop in PCT level, with a half-life of approximately 24 hours. Serial PCT measurements are therefore useful in monitoring the effectiveness of treatment. No accepted risk score has been developed for PCT, but a level of >10ng/mL indicates a high likelihood of bacterial severe sepsis or septic shock. 
 
Non-infectious severe inflammatory reactions may lead to an increase in PCT, but the return to normal levels in these instances is usually rapid. In general an elevated PCT is more specific for severe bacterial infection than acute phase reactants such as C-reactive protein (CRP). There is no international PCT standard; PCT levels generated in different labs should therefore not be compared as the methodology and reference intervals may differ.
Reference Range Information
Performing Location Reference Range
All Performing Sites

Neonates 0-72 hours: (See graph: Procalcitonin (PCT) Levels in the Neonate)


Neonates >72 hours-adults: <0.05 - 0.10 ng/mL​

Interpretation

​* INTERPRETATION


Age: 0-72 hours
PCT value: Any
Interpretation: In the absence of bacterial infection, procalcitonin values begin to rise immediately at birth, peak at Day 2, and then fall to adult levels (0.0-0.1ng/mL) by Day 3 of life. Nevertheless, neonatal PCT levels predictably rise above the baseline in response to severe bacterial infections. (See graph: Procalcitonin (PCT) Levels in the Neonate)
Also refer to C. Chiesa et al, 1998. Reliability of procalcitonin concentrations for the diagnosis of sepsis in critically ill neonates. Clin. Infect. Dis. 26:664.)

Age: >72 hours
PCT value: 0.00-0.10 ng/mL
Interpretation: Significant bacterial infection unlikely.
 
Age: >72 hours
PCT value: 0.11-0.50 ng/mL
Interpretation: Significant bacterial infection possible; retest 12-24hrs; consider clinical picture, other diagnostic studies.
 
Age: >72 hours
PCT value: 0.51-2.00 ng/mL
Interpretation: Significant bacterial infection likely; consider clinical picture and other diagnostic studies.
 
Age: >72 hours
PCT value: >2.00 ng/mL
Interpretation: Significant bacterial infection likely; patient is at increased risk for bacterial sepsis and/or septic shock.
Outreach CPTs
CPT Modifier
(if needed)
Quantity Description Comments
84145​ 1​ Enzyme-linked fluorescent assay (ELFA)​
Ordering Applications
Ordering Application Description
​Centricity ​Procalcitonin, Serum
​Cerner ​None
If the ordering application you are looking for is not listed, contact your local laboratory for assistance.
Specimen Requirements
 
 
 
Fasting Required Specimen Type Preferred Container/Tube Acceptable Container/Tube Specimen Volume Specimen Minimum Volume
(allows for 1 repeat)
Pediatric Minimum Volume
(no repeat)
​No Serum​Serum Separator Tube (SST)​Red Top Tube (RTT)0.5 mL​
Collection Processing

Separate serum from the blood within 60 minutes of venipuncture. Serum specimen must be clear and free of red cells, particulate matter including fibrins which interferes with the assay.
Specimens containing free red cells, particulate matter including fibrins should be re-centrifuged. Frozen specimens should be brought to room temperature and re-centrifuged to get a clear specimen.

Outreach specimens should be sent frozen. Three freeze and thaw cycles are acceptable.​

Specimen Stability Information
Specimen Type Temperature Time
Serum​ ​ Refrigerate​ < 48 hours​​
Frozen at -20 deg Celsius​

> 48 hours​

Stable up to 6 months

Rejection Criteria
Grossly hemolyzed​
Grossly lipemic​
Grossly icteric​
Greater than three freeze/thaw cycles
Reference Range Information
Performing Location Reference Range
All Performing Sites

Neonates 0-72 hours: (See graph: Procalcitonin (PCT) Levels in the Neonate)


Neonates >72 hours-adults: <0.05 - 0.10 ng/mL​

Interpretation

​* INTERPRETATION


Age: 0-72 hours
PCT value: Any
Interpretation: In the absence of bacterial infection, procalcitonin values begin to rise immediately at birth, peak at Day 2, and then fall to adult levels (0.0-0.1ng/mL) by Day 3 of life. Nevertheless, neonatal PCT levels predictably rise above the baseline in response to severe bacterial infections. (See graph: Procalcitonin (PCT) Levels in the Neonate)
Also refer to C. Chiesa et al, 1998. Reliability of procalcitonin concentrations for the diagnosis of sepsis in critically ill neonates. Clin. Infect. Dis. 26:664.)

Age: >72 hours
PCT value: 0.00-0.10 ng/mL
Interpretation: Significant bacterial infection unlikely.
 
Age: >72 hours
PCT value: 0.11-0.50 ng/mL
Interpretation: Significant bacterial infection possible; retest 12-24hrs; consider clinical picture, other diagnostic studies.
 
Age: >72 hours
PCT value: 0.51-2.00 ng/mL
Interpretation: Significant bacterial infection likely; consider clinical picture and other diagnostic studies.
 
Age: >72 hours
PCT value: >2.00 ng/mL
Interpretation: Significant bacterial infection likely; patient is at increased risk for bacterial sepsis and/or septic shock.
For more information visit:
Performing Laboratory Information
Performing Location Day(s) Test Performed Analytical Time Methodology/Instrumentation
Diagnostic and Treatment Center​ ​Monday through Sunday ​Less than 2 hours ​Enzyme Immunoassay (EIA) bioMerieux​
​Eau Claire ​Monday through Sunday ​Less than 2 hours ​Enzyme Immunoassay (EIA) bioMerieux​
​Flambeau ​Monday through Sunday ​Less than 2 hours ​Enzyme Immunoassay (EIA) bioMerieux​
Marshfield​ Monday through Sunday​ Less than 2 hours​ Enzyme Immunoassay (EIA) bioMerieux​
​Neillsville​Monday through Sunday​Less than 2 hours​Enzyme Immunoassay (EIA) bioMerieux​
​Minocqua​Monday through Sunday​Less than 2 hours​Enzyme Immunoassay (EIA) bioMerieux
For billing questions, see Contacts
Outreach CPTs
CPT Modifier
(if needed)
Quantity Description Comments
84145​ 1​ Enzyme-linked fluorescent assay (ELFA)​
For most current information refer to the Marshfield Laboratory online reference manual.