Diagnostic utility of procalcitonin as a biomarker for late-onset neonatal sepsis.

Background: To explore the diagnostic utility of procalcitonin (PCT) as a biomarker for late-onset neonatal sepsis (LONS).

Methods: The clinical and laboratory data of 131 neonatal patients in the neonatal intensive cares unit (NICU) of our center (Department of Neonatology, Renmin Hospital of Wuhan University) from June 1, 2015, to May 31, 2018, were retrospectively analyzed. These patients were divided into 3 groups based on their disease conditions: the bacterial sepsis (BS) group (n=47), the fungal sepsis (FS) group (n=39), and the normal control group (n=45, without sepsis). Blood cultures, routine blood tests, and testing for PCT and C-reactive protein (CRP) were performed in all 3 groups. Both PCT and CRP were measured by using enzyme-linked immunosorbent assay (ELISA). Blood culture was performed in an automated blood culture system. Routine blood tests were performed by using a fully automatic hematology analyzer.

Results: Serum PCT level was significantly different between the BS group and control group (P<0.01) but showed no significant difference between the FS group and control group (P>0.05); the difference in CRP was statistically significant between the FS group and control group (P<0.01) but was not statistically significant between the BS group and control group (P>0.05). The areas under the receiver operating characteristics (ROC) curve were 0.979 and 0.826 for PCT/CRP in the BS group and FS group, with a best cutoff value of 0.93 and 33.27, respectively; the sensitivities and specificities of PCT/CRP in these 2 groups were 0.962/0.679 and 0.964/0.964, respectively.

Conclusions: Compared with CRP, PCT is more sensitive in diagnosing BS but is not sensitive for diagnosing FS. Therefore, PCR is a useful biomarker in distinguishing BS from FS in neonates with late-onset sepsis.