W143 - Dynamic Peripheral Immune Proteins in Extremely Premature Infants

There has been a recent shift in the paradigm that susceptibility to inflammatory diseases in premature infants is due to a poorly developed immune system. Yet, how postnatal changes immunity profile result in disease is poorly understood. Serial analysis of immune proteins in plasma in preterm infants at risk of disease can provide insight into the trajectory of postnatal immune development. 

Preterm blood samples (n=5) were obtained within the first three days of life, 7-10 days, 2 weeks, 1 month and 2 months of age (total n=22 samples). Cord blood samples obtained from term infants (TCB, n=5) and peripheral blood from adults (AB, n=5) served as controls. Protein expression from dried blood spots was analyzed.

The peripheral immune profile of preterm infants was distinct from both TCB and AB. In premies, the immune profile in the first two weeks of life differed from that of samples obtained at 1 and 2 months of age. Expression of proteins involved in innate immunity IFNLR1(Interferon lambda receptor 1(IFNLR1), TREM1(triggering receptor expressed on myeloid cells 1) and adaptive immunity LAG3 (lymphocyte activating 3) and CD28 were increased in the first two weeks of life. Meanwhile, expression of IL6 was highly variable in the first two months of life. PTHR1 (parathyroid hormone receptor 1) was higher in preterm infants compared to CB and higher levels persisted through the first two months of life. The peripheral immune profile in extremely premature infants is distinct and dynamic in early life.