Immune cell subsets at birth may help to predict risk of late-onset sepsis and necrotizing enterocolitis in preterm infants

• Prospective study on 40 preterm patients (26-30 weeks)
• Analysis of immune cell subsets within 7 days after birth
• Ten color flow cytometric analysis
• Prediction of LOS and NEC CD56bright and CD56negative CD16positive NK cells, NK cells proportion and CD3 + CD8 + CD45RA + CD62L + T cells
• Early warning system for the bed side clinician

BackgroundParameters predicting late-onset sepsis (LOS) and necrotizing enterocolitis (NEC) in preterm infants would be valuable. Ten-color flow-cytometry enables the estimation of cellular immune status requiring only small sample volumes.AimsIdentifying predictive parameters for LOS and NEC in the cellular immune status of preterm infants.Study design and subjectsIn this prospective study in 40 preterm infants (week 26 + 0 to 30 + 6) and 10 healthy full-term newborn infants (control group, week 37 + 0 to 40 + 6), flow cytometric analyses of lymphocyte subpopulations were performed between the 2nd and the 6th day of life, with a follow-up until the preterm infant reached the calculated gestational age of week 40. Patients' episodes of infections and NEC were analyzed according to the NEO-KISS criteria of the German National Reference Center.ResultsTen preterm infants showed events within the first week of life and were excluded from the analysis. Of the other 30, five developed NEC, twelve LOS. In patients with LOS, the proportion of double-negative (DN) T cells was significantly elevated compared to patients without LOS, while immune-regulatory CD56bright and CD56negCD16 + NK cells were significantly decreased (p < 0.05). Patients with NEC showed a reduction in the NK cell proportion (< 3.7%) and significantly decreased naïve cytotoxic CD45RA + CD62L + T cells (p < 0.05).ConclusionNK cells and DN-T cell counts within the first week of life may be predictors for NEC and LOS in preterm infants. In order to identify patients at risk early, further analysis of these populations might be of interest.