Sepsis has its greatest impact in the prematurely born (preterm) population. Neonatal sepsis (sepsis within the first month of life) causes over one million deaths worldwide annually, and is one of the most common, difficult and costly problems to diagnose, treat and prevent. The preterm infant can suffer rates of sepsis up to 1000-fold higher than the full-term infant, and bears the brunt of the associated mortality and lifelong sepsis-survivor morbidity.

The project is enabled by several novel, validated, microfluidic technologies that are robust and easy to use with little training. These technologies provide comprehensive measures of the functionality of blood PMN population; a critical cellular component of innate immunity. The study team will also extract high-quality nucleic acids from microfluidic-sorted PMNs for transcriptomic analyses. Collectively, these techniques require a total of 250 microliters (µL) of blood, which makes them particularly useful for preterm infants where sample volume is limited, and facilitates serial assessments with unprecedented temporal resolution of key functions of PMNs.

These studies, integrated with bioinformatics approaches, will generate new tools for diagnosing sepsis in the newborn and predicting clinical outcomes. Such approaches have the capability to dramatically change the clinical management of the preterm infant, and potentially improve long-term outcomes while reducing hospital costs.

Blood samples will be collected from two populations: preterm infants and term infants.

1. Preterm neonates (<32 weeks) the study team will collect a baseline 250 µl blood sample on day four of life and then approximately every three days, as is possible, until twenty-one days of life. In addition, for preterm neonates who have suspected sepsis, an additional 250 µl blood sample will be obtained on the day of suspected sepsis. After day twenty-one of life, 250 µl blood will be sampled one time per week until discharge, when a final 250 µl blood sample will be collected. The amount drawn for study related blood collections will not exceed the lesser of 50 ml or 3.0 ml/kg in an 8-week period.
2. Term neonates (>36 weeks) the study team will be collect a single 250 µl blood sample with the routine screen for metabolic disorders when they are >24 hours old. This will be the only study related blood collection for term neonates.

For all infants, term and preterm, the following data will be collected while the neonate is hospitalized: Demographic information (age, date of birth), past and present medical records, laboratory, microbiology, and all other test results, X-ray, CT, MRI, US and all other imaging test results, records about any medication received during admission, records of physical exam during admission, records of all vital signs and hemodynamic monitoring during admission, records of any procedure or intervention during admission, and condition at the discharge and discharge location.

Inclusion Criteria:

• For preterm neonates <32 weeks gestation at birth with no known or suspected congenital anomalies.
• For term neonates >36 weeks gestation at birth with no known or suspected congenital anomalies.

Exclusion Criteria:

• Congenital defects, suspected genetic disorders, 32-36 weeks completed gestation, or lack of consent.

Healthy Adult:

• Inclusion criteria Between the ages of 18 and 65 years of age
• Exclusion Criteria Taking any immune modifying medications or have an active immune modifying disease process

Preterm neonates <32 weeks gestation. Term neonates >36 weeks gestation.