A prospective observational study of neutrophil CD64 as a diagnostic marker in neonatal sepsis

Background: Neonatal sepsis is a major cause of mortality in the developing countries. With current investigations like septic screening and blood culture and sensitivity is not capable to early diagnosis of sepsis and have some limitations. Methods: This prospective observational study was conducted in the Department of Neonatology and Department of Microbiology and immunology, BSMMU after approval by Institutional review board over a one-year period from May 2021 to April 2022. During the study period, a total of 590 neonates were admitted in NICU of BSMMU. Among them 157 neonates with suspected neonatal sepsis were admitted. Among these 157 newborns, 64 were excluded. Finally, 93 patients were included and analysed in the study. Results: Total 157 patients with suspected sepsis were admitted during study period. Among them 64 newborns were excluded on basis of different exclusion criteria. Baseline characteristics of enrolled neonates 56(60.2%) were male. Mean gestational age 33.63±3.463 and mean birth weight 1863.23±773.202. Majority of the baby were inborn 68 (73.1%) and mode of delivery was LUCS. Maternal Risk factor for early onset sepsis like fever, UTI, PROM was not statistically significant. Hb and platelet significantly decreased in proven sepsis group. CRP significantly increased in proven sepsis group than clinical sepsis group. Mean nCD64 (%) was 83.62±16.665 and 57±34.277 in proven and clinical sepsis group respectively. It was significantly (P less than 0.001) increased in proven sepsis group. In ROC curve cut-off value for nCD64 in proven sepsis group was 71.5%. For sepsis diagnosis nCD64 showed sensitivity and specificity were 80% and 56% respectively. Calculating PPV and NPV were 71% and 74% respectively. nCD64 has an area under the curve (AUC) of 0.718. So, it is a moderately accurate marker for the diagnosis of neonatal sepsis. Conclusions: Flow cytometric assessment of neutrophil CD64 was found more in neonates with culture proven sepsis than clinical sepsis. nCD64 has a good sensitivity 80% and specificity 56% and PPV, NPV 71%,74% respectively in culture proven sepsis with a cut-off value 71.5%.