Procalcitonin in children admitted to hospital with community acquired pneumonia

Abstract

Aims-To assess the sensitivity, specificity, and predictive value of procalcitonin (PCT) in diVerentiating bacterial and viral causes of pneumonia. Methods-A total of 72 children with community acquired pneumonia were studied. Ten had positive blood culture for Streptococcus pneumoniae and 15 had bacterial pneumonia according to sputum analysis (S pneumoniae in 15, Haemophilus influenzae b in one). Ten patients had Mycoplasma pneumoniae infection and 37 were infected with viruses, eight of whom had viral infection plus bacterial coinfection. PCT concentration was compared to C reactive protein (CRP) concentration and leucocyte count, and, if samples were available, interleukin 6 (IL-6) concentration. Results-PCT concentration was greater than 2 µg/l in all 10 patients with blood culture positive for S pneumoniae; in eight of these, CRP concentration was above 60 mg/l. PCT concentration was greater than 1 µg/l in 86% of patients with bacterial infection (including Mycoplasma and bacterial superinfection of viral pneumonia). A CRP concentration of 20 mg/l had a similar sensitivity but a much lower specificity than PCT (40% v 86%) for discriminating between bacterial and viral causes of pneumonia. PCT concentration was significantly higher in cases of bacterial pneumonia with positive blood culture whereas CRP concentration was not. Specificity and sensitivity were lower for leucocyte count and IL-6 concentration. Conclusions-PCT concentration, with a threshold of 1 µg/l is more sensitive and specific and has greater positive and negative predictive values than CRP, IL-6, or white blood cell count for diVerentiating bacterial and viral causes of community pneumonia in untreated children admitted to hospital as emergency cases. (Arch Dis Child 2001;84:332-336)

Procalcitonin and community-acquired pneumonia (CAP) in children

“…Several authors [6][7][8][9][10][11][12][13][14] have investigated the role of PCT as a serum marker for differentiating bacterial and viral CAP in children, individually or combined with other inflammatory markers. Generally, two hypotheses emerged: one confirming the usefulness of PCT in distinguishing the etiology of CAP, the other finding no usefulness.…”

“…In 2001, Moulin et al [7] investigated the role of several markers for the rapid identification of bacterial vs viral pneumonia in 72 children (inpatients form the ages 2 months to 13 years), finding that the PCT value of 1 ng/ml differentiates between bacterial infection and viral pneumonia more effectively (AUC: 0.93; 95% CI 0.85-0.97) than CRP (AUC: 0.84, 95% CI 0.73-0.91), and interleukin 6 (IL-6) (AUC 0.64, 95% CI 0.45-0.80).…”

“…Since each study has been carried out using different methodological approaches, from the enrollment criteria to laboratory analysis, different cut-offs have been used to assess the diagnostic performance of each marker and to eventually identify the best predictor [6,10,12,14]. Toikka [6], in 2000, and Moulin [7], in 2001, chose to evaluate IL-6 in addition to PCT and CRP, in order to assess the etiology of CAP. The results were similar when analyzing the comparison between PCT and IL-6 diagnostic performances, showing PCT to be more accurate than IL6, while they conflicted when comparing PCT and CRP.…”

Blood Culture in Evaluation of Pediatric Community-Acquired Pneumonia: A Systematic Review and Meta-analysis

“…32 Two studies examined radiographic features in CAP, 33,34 1 evaluated antimicrobial use in the treatment of CAP, 35 and 1 examined infl ammatory markers in CAP. 36 Four studies evaluated bacteremia in children with CAP, [37][38][39][40] 1 study examined management of CAP, 41 and another focused on severe CAP admissions to the ICU. 42 The majority of studies used observational cohort design, except for 1 study that used a nested case-control design.…”

“…Six studies were assessed as good, 36,37,39-42 11 were fair, 23,24,[26][27][28][30][31][32]34,35,38 and 4 were poor. 22,25,29,33 Poorly rated studies suffered from outcomes that were not clearly described, omission of followup of participants, and lack of adequate adjustment of confounding in the analyses.…”