Value of different markers in the prompt diagnosis of early-onset neonatal sepsis

Abstract

We read with great interest the recent article by Altunhan et al. whose study objective was to determine the diagnostic value of procalcitonin (PCT) at birth and at 24 h of age in the prompt diagnosis of early-onset neonatal sepsis (EONS).1Altunhan H. Annagür A. Örs R. Mehmetoğlu I. Procalcitonin measurement at 24 hours of age may be helpful in the prompt diagnosis of early-onset neonatal sepsis.Int J Infect Dis. 2011; 15: e854-e858Abstract Full Text Full Text PDF PubMed Scopus (60) Google Scholar The authors reported similar PCT levels in newborns with prolonged rupture of the membranes and the control group at birth, but higher PCT levels in the study group at 24 h of age. PCT and C-reactive protein (CRP) thresholds for the diagnosis of sepsis were 5.38 ng/ml (sensitivity 83.3%, specificity 88.6%) and 12 mg/l (sensitivity 76.4%, specificity 78.9%) at 24 h of age. We previously investigated the value of interleukin-6 (IL-6) and CRP in the diagnosis of sepsis in a study that included 170 proven sepsis, 62 clinical sepsis, and 50 control patients.2Celik I.H. Demirel F.G. Uras N. Oguz S.S. Erdeve O. Biyikli Z. et al.What are the cut-off levels for IL-6 and CRP in neonatal sepsis?.J Clin Lab Anal. 2010; 24: 407-412Crossref PubMed Scopus (75) Google Scholar IL-6 and CRP results were similar in both the early and late sepsis groups; IL-6 had a sensitivity of 72% and specificity of 84%, and CRP had a sensitivity of 67% and specificity of 97%. In another more recent study, we evaluated neutrophil volume, conductivity, and scatter (VCS) parameters in the diagnosis and treatment efficacy of neonatal sepsis.3Celik I.H. Demirel G. Aksoy H.T. Erdeve O. Tuncer E. Biyikli Z. et al.Automated determination of neutrophil VCS parameters in diagnosis and treatment efficacy of neonatal sepsis.Pediatr Res. 2012; 71: 121-125Crossref PubMed Scopus (42) Google Scholar These parameters and their distribution width (DW) were evaluated using a hematology analyzer without any extra blood collection to the complete blood count. The study included 304 newborns: 76 with proven sepsis, 130 with clinical sepsis, and 98 controls. Mean neutrophil volume (MNV) had a sensitivity of 79%, specificity of 82%, positive predictive value (PPV) of 90%, and negative predictive value (NPV) of 65%. We also investigated the influence of sepsis time and found that patients with early- and late-onset sepsis had similar VCS levels. In this study, MNV, IL-6, and CRP were found to be independent risk factors of sepsis in the logistic regression analysis, and a combination of these parameters gave a sensitivity of 94%, specificity of 88%, PPV of 95%, and NPV of 86%. In conclusion, although we agree that PCT is a more sensitive marker of infection than CRP, markers such as PCT, IL-6, CRP, and MNV have similar sensitivity and specificity alone. A combination of these parameters gives better results. We suggest that different combinations with minimal blood collection and expense should be used to strengthen the diagnosis of both early- and late-onset neonatal sepsis. Conflict of interest: No competing interest declared.