CD64 cell surface expression on neutrophils for diagnosis of neonatal sepsis

Neonatal sepsis (NS) continues to be one of the most significant causes of neonatal morbidity and mortality. Early identification of Neonatal sepsis is a major diagnostic problem because of the nonspecific clinical signs and limitations of the current diagnostic procedures. Neutrophil CD64 expression has been proposed as a diagnostic test for evaluation of infection and sepsis. We compared the diagnostic utility of neutrophil CD64 expression with IL-6, IL-8, TNFalpha and CRP assays. Peripheral blood samples were taken from 25 neonates classified into two groups; proven NS (n = 15), clinical NS (n = 10) and healthy newborns (n = 10). CD64 expression was analysed by flowcytometry, while serum level of interleukins (IL-6, IL-8), and TNFalpha was determined by ELISA. Expression of CD64 was significantly enhanced in the groups with proven sepsis and clinical NS as compared to the controls (P < 0.05). Similary, TNFalpha, IL-6, IL-8 and CRP levels were significantly elevated in the groups with sepsis and clinical NS as compared to the controls (P < 0.05). Our data indicate that, in addition to serum levels of interleukins (IL-6, IL-8), and TNFalpha, expression of CD64 on neutrophils by flowcytometry could be useful as an indicator of NS due to its early appearance, sensitivity and specificity (96%). In conclusion, neutrophil expression of CD64 is a useful diagnostic tool for early detection of neonatal sepsis. The assay is rapid, easy and reliable.