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.