Immunophenotyping of very preterm infants at risk of developing sepsis and necrotizing enterocolitis

Objective To characterize adaptive immunity in very preterm neonates and assess potential immunological markers associated with infection risk. Study Design: Peripheral blood lymphocytes of 30 very preterm neonates (mean birth weight 815g) were analyzed using 9-color flow cytometry on days 0–7, 8–14, and 15–28 of life. Statistical analyses included group comparisons and longitudinal trends. Results Six neonates (20%) developed sepsis; one (3%) developed necrotizing enterocolitis. T and B cell compartments were dominated by naïve T cells and unswitched CD27- B cells, respectively. The CD4/CD8 ratio was elevated initially, declining significantly after the first week. No consistent immunological predictors of infection were identified, though infected neonates showed higher B cell proportions in week two. Conclusion V ery preterm neonates exhibit marked immaturity of adaptive immunity. Immunophenotyping may enhance understanding of neonatal immune development and, together with clinical parameters, aid in early risk stratification.