A Review of the Different Haematological Parameters and Biomarkers Used for Diagnosis of Neonatal Sepsis

Neonatal sepsis is a major cause of morbidity and mortality in newborns. It presents a diagnostic challenge to the neonatologists due to a lack of objective evaluation. It may mimic noninfective conditions, such as inborn error of metabolism, birth asphyxia, and even respiratory distress syndrome in preterms. Nonetheless, over-diagnosis and initiating unwanted empirical antibiotics may pose the threat of drug resistance, increasing the hospital stay and cost of treatment. Traditionally, investigations such as white blood cell count, absolute neutrophil count, immature to total neutrophil ratio, C-reactive protein levels, and blood cultures have been used to diagnose sepsis. However, these have low sensitivity and specificity because they may be elevated in conditions other than sepsis. The in-depth understanding of the neonatal immune system’s response to early infection has led to the discovery of advanced diagnostic tools, including biomarkers. This literature review briefs on the various haematological parameters and biomarkers in neonatal sepsis, exploring newer biomarkers and comparing them with their older counterparts. This will help early diagnosis, treatment, and improved prognosis in neonatal sepsis. As there is a spectrum of markers for diagnosing neonatal sepsis, it is preferable to compile these markers and correlate clinically. A thorough search of this literature was done on the electronic databases PubMed, Elsevier’s Web of Science, and the Cochrane Library. The authors found around 90 relevant articles: 84 were from PubMed, 4 from Elsevier, and 2 from the latest Cochrane database. Of these articles, 57 were selected from between early 2000 and January 2019.