Evaluation of immune function in preterm infants using Immuknow® assay

Background. Neonatal immune system is not fully developed at birth; newborns have an adequate leukocytes and lymphocytes count at birth but these cells lack of function. Objective. To assess the functional activity of T-cells at birth and at 30 days of life and the influence of the main perinatal factors in a population of preterm infants. Design. A prospective longitudinal study was carried out in a population of 59 preterms. Fifteen healthy adults were included as a control group. Blood samples were collected at birth and at 30 days of life to evaluate CD4+ T cell activity using the Immuknow® assay. Results. CD4+ T cell activity at birth and at 30 days of life were significantly lower compared with adult controls (p < .001). Twins showed lower activity compared to singletons (p= .005). Infants born to vaginal delivery had higher CD4+ T cell activity compared to those born to c-section (p=0.031); infants born after pPROM showed a higher activity at birth (p= .002). Low levels of CD4+ T cells activation at birth were associated with necrotizing enterocolitis development in the first week of life (p=.049). Conclusions. Preterm infants show a lack in CD4+ T cells activation at birth. Perinatal factors such as intrauterine inflammation, mode of delivery, zygosity can influence the levels of adaptative immune activity at birth and can contribute to expose these infants to serious complications such as NEC.