Comparison of serum amyloid A concentrations with those of C-reactive protein and procalcitonin in diagnosis and follow-up of neonatal sepsis in premature infants.

OBJECTIVE: The purpose of this study was to determine the role of serum amyloid A (SAA) in diagnosis of neonatal sepsis and evaluation of clinical response to antibiotic therapy. We also aimed to compare the efficiency of SAA with that of C-reactive protein (CRP) and procalcitonin (PCT) in diagnosis and follow-up of neonatal sepsis in preterm infants.

STUDY DESIGN: A total of 163 infants were enrolled in this prospective study. The infants were classified into four groups: group 1 (high probable sepsis), group 2 (probable sepsis), group 3 (possible sepsis) and group 4 (no sepsis, control group). Blood samples for whole blood count, CRP, PCT, SAA and culture were obtained before initiating antibiotic treatment. This procedure was repeated three times at 48 h, 7 and 10 days.

RESULT: Initial CRP, PCT and SAA levels were found to be positive in 73.2, 75.6 and 77.2% of all infants, respectively. Sensitivities of CRP, PCT and SAA at 0 h were 72.3, 74.8 and 76.4%, respectively. Although it was not statistically significant, SAA was found to be more sensitive than CRP and PCT in diagnosis of neonatal sepsis. The area under the curve (AUC) for CRP, PCT and SAA at 0 h were 0.870, 0.870 and 0.875, respectively. Although the AUC for SAA at 0 h was higher than PCT and CRP, the difference was not statistically significant.

CONCLUSION: SAA is an accurate and reliable marker for diagnosis and follow-up of neonatal sepsis. It is especially useful at the onset of inflammation for rapid diagnosis of neonatal sepsis and can be safely and accurately used in combination with other sepsis markers such as CRP and PCT in diagnosis and follow-up of neonatal sepsis in preterm infants.