Neutrophil CD64 has a high negative predictive value for exclusion of neonatal sepsis

Abstract

Background and aim. Neonatal sepsis is a signicant contributor to morbidity and mortality globally. Blood culture is the most reliable
method for detection of bacterial infection. However, its sensitivity is low and its use in the diagnosis of bacteraemia is fraught with dificulties. CD64 antigen is up-regulated in neutrophils only when they are activated, and has been shown to be a potential biomarker for infection. The primary objective of this study was quantitation of neutrophil CD64 by .ow cytometry in neonates with signs and symptoms suggestive of sepsis/infection in the rst 4 weeks of life.
Methods and results. In this prospective observational study, patients were classied into categories of infection, namely denite, probable and possible. Of 76 neonates, 1 had denite infection, 5 probable infection, 30 possible infection, and 32 no infection. .e neutrophil CD64 index at a cut-o. value of 1.8 had a high negative predictive value (95.2%) in ruling out combined probable and denite infection.
Conclusions. We recommend inclusion of the neutrophil CD64 index into the diagnostic algorithm for neonatal sepsis, as it has a high negative predictive value and can be used to rule out infection. As the positive predictive value of the index was low in conrming infection, it should be used as a screening rather than a conrmatory test.