II. Indication
- Marker of Bacterial Infection and Sepsis
III. Physiology
- Peptide produced in the Thyroid, lung and Intestine
- Calcitonin precursor (involved in Calcium Homeostasis)
- Remains at low levels when well
- Increases in inflammatory states, rising within 4 hours of infection onset and peaking at 12 to 48 hours
- Postulated to increase markedly, and selectively in Bacterial Infection
- Postulated to allow for monitoring treatment response due to Procalcitonin short Half-Life
- Contrast with Interferon gamma, which increases in Viral Infections and decreases Procalcitonin
IV. Interpretation
- Procalcitonin level <0.05: Normal
- Procalcitonin level <0.25: Bacterial Sepsis unlikely
- Vijayan (2017) J Intensive Care 5:51 +PMID: 28794881 [PubMed]
V. Efficacy: Adults
- Mediocre efficacy in Sepsis diagnosis
- Low efficacy in Bacterial Pneumonia diagnosis
- Worse outcomes in ICU when Procalcitonin was used to direct antibiotic management
- May allow shortening of antibiotic course in Sepsis and respiratory infections without adversely affecting outcomes
VI. Efficacy: Children
- See Serious Bacterial Infection in Children (Occult Bacteremia)
- Serious Bacterial Infection in Neonatal Fever
- Variable efficacy, although initial studies had very high accuracy in septic children
- Test Sensitivity: 26-55% for Bacterial Infection
- Test Specificity: 75 to 82% for Bacterial Infection
- Interpretation
- PCT <0.5 ng/ml has a Negative Predictive Value for serious Bacterial Infection of 90%
- PCT >0.6 (and WBC >19k, blasts >1.8k, Neutrophils >13k) suggests serious Bacterial Infection
- References
VII. References
- Orman, Herbert, Spiegel in Herbert (2016) EM:Rap 16(10):12-3
- Morgenstern in Swadron (2022) EM:Rap 22(9): 4-6
- Dolatabadi (2015) Niger Med J 56(1):17-22 +PMID:25657488 [PubMed]
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Related Studies
| Concepts | Amino Acid, Peptide, or Protein (T116) , Biologically Active Substance (T123) |
| MSH | C029100 |
| SnomedCT | 418752001 |
| LNC | LP31682-5, MTHU015794 |
| English | calcitonin precursor polyprotein, Calcitonin, pro-, pro calcitonin, procalcitonin, Procalcitonin, Calcitonin precursor polyprotein, Procalcitonin (substance) |
| Spanish | procalcitonina (sustancia), procalcitonina |
