Comparison of procalcitonin with CRP and differential white blood cell count for diagnosis of culture-proven neonatal sepsis.

We analysed the utility of procalcitonin (PCT) assay, either alone or in combination with 2 simple blood assays, for the diagnosis of culture-proven neonatal septicaemia. Tests for serum PCT concentration, serum CRP concentration and blood immature to total neutrophil leucocyte ratio all had reasonable (58-77%) sensitivity, reasonable (62-84%) specificity, good (94-97%) negative predictive value and poor (16-24%) positive predictive value for the diagnosis of sepsis. Algorithms combining various tests produced slight improvements in sensitivity or specificity. Although the PCT test appeared to be useful for the diagnosis of neonatal sepsis in this small study, it did not offer any significant advantages over traditional tests for the diagnosis of infection.