Procalcitonin - a sensitive inflammation marker of febrile episodes in neutropenic children with cancer

Objective: Sensitive parameters of inflammations are rare or of limited validity in neutropenic patients. Procalcitonin (PCT) proven to be a sensitive inflammatory marker in nonneutropenic patients was evaluated for its diagnostic relevance in febrile episodes of neutropenic patients with cancer. Methods: Plasma levels of PCT were determined by an immunoluminometric assay in children with febrile neutropenic episodes (n = 376) starting at the date of admission until the resolution of fever and were correlated with serum levels of the C-reactive protein (CrP). Febrile episodes were classified as fever of unknown origin (FUO), microbiologically or clinically documented infections and were also differentiated according to the site of the infection (unknown, bacteremia, respiratory, soft tissue, gastrointestinal and urinary tract infection). Results: Independently from the aetiology and the site of infection the PCT peak value occurred mostly on the second hospital day and decreased rapidly in cases of successful antibiotic therapy and with the resolution of fever to the normal range (0.1-0.5 mu g/l). The highest PCT peak levels at the onset of fever and during the febrile course were observed in patients with gramnegative bacteremia (n = 22, median 12.1 mu g/l, range 0.4-568.2 mu g/l). There was a positive correlation between PCT peak levels and CrP peak levels (r = 0.48, p = 0.001) which mostly were observed 24 h later than for PCT. Conclusions: PCT is a sensitive and specific parameter in the diagnostic and in the sequential assessment, of febrile neutropenic episodes, especially in gramnegative infections. Its diagnostic accuracy in neutropenic patients is clearly higher than that of CrP.