An update on the use of C-reactive protein in early-onset neonatal sepsis: current insights and new tasks.

C-reactive protein (CRP) is one of the most studied and most used laboratory tests for neonatal sepsis. As part of the acute-phase reaction to infection, it plays a central role in the humoral response to bacterial invasion. The delayed synthesis during the inflammatory response accounts for its low sensitivity during the early phases of the disease. Diagnostic accuracy clearly improves by the performance of serial determinations and by the combination with earlier markers such as interleukins or procalcitonin. CRP is as well particularly useful for monitoring the response to treatment and guiding antibiotic therapy, though nothing replaces the clinical impression and the gold standard (i.e. culture results). In spite of the large amount of research done on CRP in neonates, some topics are still not fully understood, such as the influence of noninfectious factors on CRP levels in healthy as well as in symptomatic neonates and the role of gestational age and birthweight on CRP kinetics. In this review, we aim to give an update on the current evidence on the use of CRP in neonates.