Procalcitonin Correlates With but Is Not Superior to Other Diagnostic Markers of Bacterial Pneumonia.
OBJECTIVES
Despite extensive research on procalcitonin (PCT)-guided therapy in lower respiratory tract infections, the association between PCT and bacterial pneumonia remains unclear.


METHODS
We evaluated retrospectively the performance of PCT in patients presenting with lower respiratory tract infection symptoms and grouped by seven diagnoses. All patients had microbial testing, chest imaging, and CBC counts within 1 day of PCT testing.


RESULTS
Median PCT level in patients diagnosed with bacterial pneumonia was significantly higher than in patients diagnosed with other sources of infections or those not diagnosed with infections. Median PCT levels were not different among patients grouped by type or quantity of pathogen detected. They were significantly higher in patients with higher pathogenicity scores for isolated bacteria, those with abnormal WBC count, and those with chest imaging consistent with bacterial pneumonia. A diagnostic workup that included imaging, WBC count, and Gram stain had an area under the receiver operating characteristic curve of 0.748, and the addition of PCT increased it to 0.778.


CONCLUSIONS
PCT was higher in patients diagnosed with bacterial pneumonia. Less clear is its diagnostic ability to detect bacterial pneumonia over and above imaging and laboratory data routinely available to clinicians.
['Ayala-Lopez|Nadia|N|', 'Peaper|David R|DR|', 'Harb|Roa|R|']
D000328:Adult D000368:Aged D015415:Biomarkers D005260:Female D006801:Humans D008297:Male D008875:Middle Aged D018410:Pneumonia, Bacterial D000077740:Procalcitonin D012189:Retrospective Studies
Procalcitonin Pneumonia Imaging Bacteria Diagnosis Viruses