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Published on: August 7, 2017
Procalcitonin, C-reactive protein and leukocyte count in children with lower respiratory tract infection
Cristina Prat1, Josep Domínguez, Carlos Rodrigo
1Servei de Microbiologia, Hospital Universitari Germans Trias i Pujol, C/Canyet s/n, 08916 Badalona, Spain. crisprat@ns.hugtip.scs.es
Insights
Procalcitonin (PCT) and C-reactive protein (CRP) effectively help differentiate bacterial from viral lower respiratory tract infections in children. These biomarkers aid in guiding antibiotic treatment decisions when the specific pathogen is unclear.
Area of Science:
- Pediatric Infectious Diseases
- Clinical Biochemistry
- Diagnostic Biomarkers
Background:
- Lower respiratory tract infections (LRTI) are common in children, often leading to empirical antibiotic use.
- Rapid etiological diagnosis of LRTI is challenging, with pathogens frequently unidentified.
- Clinical and laboratory factors alone do not reliably distinguish bacterial from viral LRTI.
Purpose of the Study:
- To assess the diagnostic accuracy of procalcitonin (PCT), C-reactive protein (CRP), and leukocyte count.
- To differentiate between pneumococcal, atypical, and viral etiologies in pediatric LRTI.
Main Methods:
- Measured PCT, CRP, and leukocyte counts in children with microbiologically confirmed LRTI.
- Compared biomarker levels across different etiological groups (pneumococcal, atypical, viral).
Main Results:
- PCT and CRP levels significantly correlated with bacterial LRTI etiology; leukocyte count did not.
- PCT (cutoff 2 ng/ml) and CRP (cutoff 65 mg/l) showed moderate sensitivity and specificity for bacterial vs. viral LRTI.
- PCT and CRP demonstrated high sensitivity (90.3%) for distinguishing pneumococcal from other LRTI causes.
Conclusions:
- Elevated PCT and CRP levels are strongly associated with bacterial LRTI in children.
- PCT and CRP are valuable tools for differentiating pneumococcal infections and guiding antibiotic therapy decisions.
- PCT offers higher specificity than CRP in distinguishing bacterial from viral etiologies.
Background:
Lower respiratory tract infection is the most common infection leading to unnecessary antibiotic treatment in children. Etiologic diagnosis is not immediately achieved, and the pathogen remains unidentified in a large number of cases. Neither clinical nor laboratory factors allow for a rapid distinction between bacterial and viral etiology. The aim of our study was to evaluate the reliability of procalcitonin (PCT), C-reactive protein (CRP) and leukocyte count in distinguishing pneumococcal, atypical and viral lower respiratory tract infection.
Methods:
PCT, CRP and leukocyte count were measured in children with microbiologically documented diagnoses of lower respiratory tract infection. The results were compared of children with pneumococcal, atypical and viral etiologies.
Results:
PCT and CRP showed significant correlation with a bacterial etiology of lower respiratory tract infection. No significance was found for leukocyte count. Using a cutoff point of 2 ng/ml for PCT and 65 mg/l for CRP, the sensitivities and specificities for distinguishing bacterial from viral lower respiratory tract infections were 68.6 and 79.4% for PCT and 79.1 and 67.1% for CRP. The sensitivities and specificities for distinguishing pneumococcal from other etiologies were 90.3 and 74.1% for PCT and 90.3 and 60% for CRP, respectively.
Conclusions:
High PCT and CRP values show a significant correlation with the bacterial etiology of lower respiratory tract infection. PCT and CRP show good sensitivity for distinguishing pneumococcal from other etiologies. PCT shows higher specificity than CRP. PCT and CRP can help make decisions about antibiotic therapy in children with lower respiratory tract infections.
