[Is procalcitonin able to help in pediatric appendicitis diagnosis?]

Appendicitis clinical diagnosis in children is difficult and the acute inflammatory markers hyperleucocytis and CRP do not contribute to it.

To study the predictive value of procalcitonin (PCT) and to assess variations of its serum level according to inflammatory lesions in paediatric appendicitis.

Among 101 children aged two and 15, hospitalized for painful abdominal syndromes, 70 underwent operation for acute appendicitis and appendiceal peritonitis, 31 had no operation. PCT was evaluated in all children, normal serum concentration was <0,5 microg/L. Every appendicectomy part has been examined through histological analysis to confirm the diagnosis and the histological lesions have been classified into three categories according to their severity.

Out of 70 appendix analysed at histology, 68 (97%) were healthy and 2 (3%)were unhealthy. Among the 68 cases of healthy appendix, 19 had a PCT higher than 0,5 microg/L and among 33 cases of unhealthy appendix 4 had a PCT higher than 0,5 microg/L. The PCT mean of healthy children was not significantly different from unhealthy appendix population, appendicitis prevalence was 0,67, PCT sensitivity 28%: IC 95% [18-40], specificity 88%: IC 95% [72-97], positive predictive value 83%: IC 95% [61-95], and negative predictive value 37%: IC 95% [26-49]. PCT mean increases with the severity of inflammatory lesions of the appendix (P=0,0051).

PCT has not a good predictive value in acute paediatric appendicitis but remains a good indicator of severity in paediatric appendicitis.