430 - Plasma Microbial Cell-Free DNA in Well-Appearing Preterm Neonates

Publication Number: 2418.430

Jason B. Sauberan, Neonatal Research Institute, San Diego, CA, United States; Alice Pong, University of California, San Diego School of Medicine, San Diego, CA, United States

Background: Plasma microbial cell-free DNA (mcfDNA) testing is an emerging culture-independent diagnostic method in children. Few data exist on the normal, healthy circulating mcfDNA in the preterm neonatal host.

Objective: This study's primary aim was to explore the incidence and microbiology of positive plasma microbial cell free DNA test results in a population of preterm neonates who were well-appearing and clinically free of an active infectious disease. A secondary aim was to identify variables associated with mcfDNA-positivity in study patients.

Design/Methods: Well-appearing hospitalized preterm neonates born between 23 and 31 weeks +6 days gestational age and at least two weeks postnatal age had blood collected for plasma mcfDNA testing using a commercially available method. The frequency of organism detection, type and quantity of organism, and the relationship between test positivity and study participant infection risk factors were analyzed.

Results: Twenty-five participants were enrolled and twenty completed the study. One-half (N=10) had an organism detected in their blood using plasma mcfDNA testing. Test positivity was not associated with infection risk factors (Table 1). Both commensal and pathogenic organisms were detected. DNA concentrations were above normal values (reference intervals) in healthy adults (Table 2).

Conclusion(s): Plasma microbial cell-free DNA testing has the potential for false positive results when used in the neonatal intensive care unit. More data are needed on the taxonomy and concentration of the mcfDNA population in sick and well preterm neonates to better guide the clinical use of this newer technology in the neonatal intensive care unit.

Comparison of positive and negative participants
values are mean (SD) or % unless otherwise specified
† std. deviations were less than 3 weeks in each category
‡ values are median (range)
BW, birthweight; GA, gestational age; PNA, postnatal age; PPROM, preterm premature ruptured membranes; CPAP, continuous positive airway pressure; CVC, central venous catheter; PRBC, packed red blood cells

Characteristics of Participants (N=10) with Positive mcfDNA Results
¶ < 20 detections of the microbe in the analytical lab database
MPM, molecules per microliter; RI, reference interval