Serum procalcitonin and C-reactive protein in children with community-acquired pneumonia

1. Serum procalcitonin and C-reactive protein in children with community-acquired pneumonia K.Gogvadze, I.Guramishvili, I.Chkhaidze, K.Nemsadze, T.Maglakelidze M.Guramishvili Pediatric Clinic, State Medical University, I.Javakhishvili Diagnostic Centre, Tbilisi, Georgia

2. BACKGROUND Community acquired pneumonia is a common clinical childhood problem. Bacterial pneumonia cannot be differentiated from viral or atypical pneumonia only on the basis of patient characteristics.

3. BACKGROUND (cont.) The routine laboratory tests and chest x-ray examination discriminate poorly between bacterial, viral or atypical causes of pneumonia in children. As a result, most children with pneumonia are treated with antibiotics without knowledge of the causative agent.

4. BACKGROUND (cont.) The identification of markers of infection for differentiation of causes of pneumonia would be of great value for guiding treatment decisions and follow-up.

5. BACKGROUND (cont.) C reactive protein is a protein of the acute phase, its production is stimulated mainly by interleukin 6, interleukin 1, and tumour necrosis factor in response to infection or tissue inflammation. However, even though values of C reactive protein may reflect the severity of inflammation, its role in differentiating bacterial from viral infections is not definitely proved.

6. BACKGROUND(cont.) The usefulness of procalcitonin concentration in diagnosis, and particularly the differential diagnosis of several infectious diseases, is still the matter of some controversy, although it has become generally accepted that PCT is a useful marker for severe bacterial infections such are sepsis or meningitis.

7. The Aim The aim of the present study was to investigate PCT and CRP value in children with CAP to examine whether PCT and CRP could be used to distinguish viral, bacterial and atypical pneumonia in children.

8. Selection criteria We included only those children who were immunocompetent, who had no chronic disease, pulmonary or otherwise, and who had not received antibiotics in the 10 days before admission.

9. Patients and Methods This was an open, prospective, observational study of 36 pediatric patients with pneumonia admitted to the M.Guramishvili Pediatric Clinic, Tbilisi, Georgia from September 2004 to January 2006.

10. Patients and Methods (cont) The diagnosis of bacterial and atypical pneumonia was based on high single values and a significant rise in antibody titers between acute and convalescent sera. The diagnosis of viral pneumonia was based on virus antigen detection in nasopharyngeal aspirate and significant rise in antibody titers between acute and convalescent sera.

11. Patients and Methods (cont) The following agents had been investigated: • virus: RSV, Adenovirus, Influenza A, parainfluenza; • bacteria: Streptococcuspneumoniae, Moraxella cattarhalis, Haemophilus influenza, Staphylococcus aureus; • atypical pathogens: Chlamydia pneumonia, Mycoplasma pneumonia, Legionella.

12. Patients and Methods (cont) C-reactive protein was analyzed using an enzymimunoassay method (CRP ELISA, IBL Hamburg, Germany). Procalcitonin was measured by immunoluminometric assay (ILMA) (Brahms Diagnostica, Berlin, Germany).

13. Diagnostic criteria The diagnosis of pneumonia was based on a simultaneous finding of an infiltrate on the chest radiograph and fever (>37.5°C) and/or respiratory symptoms. The radiological diagnosis was made by two independent pediatric radiologists.

14. Flow chart of the study Presumed pneumonia n=45 Radiologically confirmed pneumonia n=36 Etiology Unknown n=8 (22%) Viral Pneumonia n=12 (33%) Bacterial Pneumonia n=11 (30%) Atypical Pneumonia n=5 (14%)

15. Etiology of CAP

16. Results: Etiology Of the 36 patients studied, 2 (mean age 2.8 years; range 0.8–6 years) had blood cultures positive for bacterial pathogen and 9 (mean age 3.9 years; range 0.5–12 years) had bacterial pneumonia diagnosed on the basis of seroconversion (9 - S.pneumonia, 2 – Haemophilus influenza).

17. Results: Etiology (cont.) Of the 36 patients studied, 12 (mean age 2.2 years; range 0.3–3.8 years) had viral pneumonia diagnosed on the basis of single IgM titre or four-fold increase of IgG titre in paired sera (5 - Adenovirus, 4 - RSV, 2 - Influenza A and 1 - Parainfluenza 3).

18. Results: Etiology (cont.) Of the 36 patients studied, 5 (mean age 2.6 years; range 0.4–5 years) had atypical pneumonia diagnosed on the basis of single IgM titre or four-fold increase of IgG titre in paired sera (3 – Chlamydia pneumonia, 2 – Mycoplasma pneumonia).

19. Values for different groups of patients with CAP

20. Results: CRP and PCT level Children with bacterial and atypical pneumonia had significantly higher PCT level than those with viral pneumonia. The significant difference in PCT concentrations was seen between bacterial and atypical pathogens.

21. Results: CRP and PCT level (cont.) The differences in the CRP levels between bacterial and viral pneumonia were significant. No significant differences in CRP level were found between atypical and viral or atypical and bacterial pneumonia.

22. Conclusion Both, serum PCT and CRP can be used for differentiation bacterial, atypical and viral pneumonia in children, though seems that the PCT is more useful than CRP.