[The serum level of C-reactive protein in neonatal sepsis]

C-reactive protein (CRP) is the most common diagnostic marker of infection.

Objectives of this study were to determine the serum CRP level in neonates with sepsis and establish the influence of gestational age (GA) on the CRP level in the first few weeks after birth.

Diagnosis of neonatal sepsis was established by the presence of clinical signs of sepsis, isolation of the causative agent of sepsis and abnormal haematological parameters. All neonates were divided into two groups: early onset sepsis (EOS) and late onset sepsis (LOS). According to GA all neonates were divided into three groups: < 32 GA, 32-36 GA and > or = 37 GA. Serum CRP was measured 0-72 h after the onset of signs and symptoms of infection.

This study included all neonates with sepsis at our Institute during 2003. EOS was diagnosed in 130 neonates (mean age was 33 weeks; range 27-41 weeks) and 33 infants (mean age 29 weeks; range 27-38 weeks). We defined a relevant CRP response as a concentration of > 10 mg/l for term and near term neonates and > 5 mg/l for preterm neonates. The maximum concentrations of CRP were reached 48 hr after the first symptoms of neonatal sepsis.

CRP levels are proportional with increasing GA and body weight in EOS. The effects of gestational age do not influence CRP levels in LOS. Maturation changes in the immune system are the most likely explanation for this and partly the organisms responsible for an infection may be different at different gestational ages and also in EOS and LOS. There is no correlation with serum CRP levels and with the severity of the disease and bad prognosis in EOS.