Evaluation of neonatal neutrophil function using the combined immunobead/NBT dye reduction assay.

An improved assay for the simultaneous assessment of phagocytic uptake (via Immunobeads) and metabolic integrity (via NBT dye reduction) was used to evaluate the neutrophil function in neonates, one year olds, and adults. The unique advantage of this assay is that it evaluates both phagocytic and killing function simultaneously which appears to make the assay more reliable in the detection of neutrophil dysfunction. This assay allowed us to establish a subtle but significant neutrophil dysfunction in full term unstressed neonates which proved to be more pronounced in both the stressed and the preterm neonates. The one year olds, however, were found to have neutrophil function comparable to that of an adult.