Change in Serum Procalcitonin in children with pneumonia caused by pathogenic microorganism.

Objective To assess the value of procalcitonin (PCT) to differentiating bacterial pneumonia from viral one. methods Of 66 children with pneumonia, 45 had bacterial pneumonia and 21 viral one. The serum PCT, C reactive protein (CRP) , interleukin 6 (IL-6) and white blood cells (WBC) were determined. Their sensitivity and specificity to bacterial and viral pneumonia were corn-paired with each other. Results CRP content was more than 60mg/l in 8 of 10 patients with S pneumonia proved by the blood culture, in whom PCT content was more than 2μg/L. In 87% of the patients with bacterial pneumonia, PCT cotent was more than 1/Mg/L. CRP content of 20mg/L had sensitivity similar to PCT of 1μg/L to distinguishing bacterial and viral infections, and much lower specificity of diagnosing bacterial and viral pneumoniae as compaired with PCT (41 % vs 86.4 % ). PCT concentration of the children with the positive blood culture of bacteria was significantly higher than that of the children with the negative blood culture of bacteria. CRP concentration was insignificantly different between both the groups of the children. The sensitivity and specificity of IL - 6 and WBC to distinguishing bacterial and viral pneumoniae were much lower than those of PCT and CRP. Conclusion PCT concentration over 1μg/L is more sensitive and specific to diagnosing bacterial infection and has greater and predictive values to distinguishing bacterial and viral infections than CRP, IL-6 and WBC.