Neutrophil CD64 as a diagnostic marker of sepsis: impact on neonatal care.

Objective: The aim of this study is to determine the validity and reliability of neutrophil CD64 in identifying infected infants and to evaluate the impact of this marker on clinical care.

Study Design: Neutrophil CD64 index was incorporated in 371 infection evaluations in 234 infants (ages 1-293 days) from 2005 to 2009 and the impact of this change on clinical care was evaluated.

Results: The sensitivity of the neutrophil CD64 assay was 87% in identifying 31 episodes of culture positive sepsis and 83% in identifying 12 infants with ventilator-associated pneumonia. There was no difference in the mean number of antibiotic days in infants with a normal CD64 versus those with a normal complete blood count (CBC) (p = 0.89), but twofold more infants were identified as "not infected" by CD64 than by CBC.

Conclusion: CD64 had a high sensitivity for identifying infected infants while also decreasing the number of infants that were exposed to unnecessary antibiotic use.