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Lab Manual for UCSF Clinical Laboratories

Lab Manual for SFGH

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Item Value
Available Stat? No
Test code PCRT
Performed by? Microbiology (Serology)
Sendout? No
Price range $$$
In House Availability This test is available only to 4E, 5E and 5R patients.
Specimen may be sent 24 hours/7 days. Test is performed twice daily, Monday - Friday, and 1x/day on Saturdays, Sundays, and holidays.
Principle Procalcitonin (PCT) is a peptide precursor of the hormone calcitonin. While calcitonin is only produced in the C cells of the thyroid gland as a result of hormonal stimulus, PCT is secreted by different types of cells from numerous organs, in response to pro-inflammatory stimulation – particularly bacterial infection. Measurement of PCT in serum can be used for diagnosis of sepsis, risk stratification, and monitoring of septic shock caused by bacterial infection.

PCT is detectable within 2 - 4 hours after a triggering event, and peaks from 12 - 24 hours afterward. The quantitative PCT level closely parallels the severity of the inflammatory insult. Higher PCT levels are associated with more severe disease, while declining levels indicate resolution of illness. Therefore, serial monitoring of PCT in patients with bacterial sepsis can be useful to monitor therapeutic response to antibacterial therapy. Specimens for serial testing should be separated by at least 8 hours.

In certain situations such as poly-trauma, burns, major surgery, prolonged or severe cardiogenic shock, or in newborns, PCT elevation may be independent of any infectious process. The return to normal values is usually rapid in these cases. Viral infections, allergies, autoimmune diseases and graft rejection do not lead to a significant increase in PCT. A localized bacterial infection can lead to a moderate increase in PCT levels.

Method The assay combines a one-step immunoassay sandwich method with a final fluorescent detection (ELFA).
Interpretation If sepsis or lower respiratory tract infection is suspected and
procalcitonin concentration is:

< 0.25 ng/mL...........low likelihood bacterial infection
0.25 - 0.49 ng/mL....equivocal likelihood bacterial infection
>/= 0.5 ng/mL............elevated likelihood bacterial infection

If antibiotics are not initiated, consider repeat procalcitonin
in 12 hours. If antibiotics are initiated, consider repeat
procalcitonin in 2-3 days to help guide duration of therapy.
Procalcitonin levels may be elevated immediately following major
trauma or surgery. Questions? Contact Infectious Diseases
Consult pager (415) 443-2847.
Container type gold top gel tube or red top tube
Amount to Collect 3 - 5 mL
Sample type Blood
Min. Volume 0.5 mL serum
Normal range < 0.25 ng/mL
Synonyms PCT;
Stability Deliver to Lab immediately after collection. Serum separated from the clot is stable at 2-8° C for up to 48 hours.
Causes for rejection 1. Blood specimens received 24 hours after collection time.
2. Add-on request to serum samples > 48 hours old.
3. Blood collected in tubes other than gold or red top.
4. Unlabeled or improperly labeled specimens.
Turn around times 24 - 48 hours (See In House Availability)
References VIDAS BRAHMS PCT Product Insert. bioMerieux, Inc., Durham, NC. 13975 B – en – 2010/09.
CPT coding 84145
Last Updated 1/5/2016 9:13:42 AM
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