Serum procalcitonin as a diagnostic marker of neonatal sepsis

values. Results: The mean PCT and CRP concentrations were respectively 56.27±81.89 and 71.14±37.17 mg/L in the “confirmed sepsis” group; 15.64±32.64 and 39.23±41.41 mg/L in the “suspected sepsis” group; 9.49±4.30 and 0.97±1.16 mg/L in the “mild infection” group; and 0.21±0.12 and 0.72±0.7 mg/L in the control group. High concentrations indicated greater severity of infection (P<0.001). Five of 18 patients with confirmed sepsis had low PCT levels (<1.0 mg/L) despite high CRP levels. In the ROC analysis, the area under the curve was 0.951 for CRP and 0.803 for PCT. The cutoff concentrations of 0.5 mg/L for PCT and 1.0 mg/L for CRP were optimal for diagnosing neonatal sepsis (sensitivity, 88.29% vs. 100%; specificity, 58.17% vs. 85.66%; positive predictive value, 13.2% vs. 33.3%; negative predictive value, 98.6% vs. 100%, respectively). Conclusion: PCT is a highly effective early diagnostic marker of neonatal infection. However, it may not be as reliable as CRP.