Near infrared spectroscopy as a biomarker for necrotising enterocolitis following red blood cell transfusion

Red blood cell transfusions (RBCTs) have been associated with necrotising enterocolitis (NEC) in preterm infants (PTIs). The objective of this report is to evaluate the use of regional cerebral (cRSO(2)) and splanchnic (sRSO(2)) tissue oximetry measured using near infrared (NIR) spectroscopy as biomarkers to evaluate the association between RBCT and NEC in a secondary analysis of a hypothesis-generating Phase I exploratory study of biomarker development. cRSO(2) and sRSO(2) were monitored in PT's receiving RBCTs. Three time periods were defined: pre-RBCT (12 h prior to RBCT), during RBCT and post-RBCT (24 h after RBCT). Three groups were defined: absence of NEC within 7 days of index RBCT (Group 11; NEC within 7 days prior (Group 2) and within 7 days after RBCT (Group 3). Mean hourly sRSO(2) and cRSO(2) were compared between groups across RBCT periods using the mixed effect method. Neonatal postnatal morbidities and treatments were included as covariates. Fifty-seven infants (median gestational age 27 weeks) received 147 RBCTs (Group 1 = 120, Group 2 = 19, and Group 3 = 8) during NIR spectroscopy monitoring. In the adjusted analysis, there was a significant change in sRSO(2) during the course of RBCT [p = 0.0405] with significant interaction with group (p < 0.0001) such that in Groups 1 and 2, sRSO(2) increased over RBCT periods, whereas in Group 3, sRSO(2) declined over RBCT periods. cRSO(2) increased during the course of the RBCT (p < 0.0001) with significant interaction with group (p = 0.0258). cRSO(2) and sRSO(2) increased significantly following RBCT in infants without NEC or NEC diagnosed prior to RBCT. Post-RBCT sRSO(2) decreased in infants who were subsequently diagnosed with NEC in this exploratory secondary analysis of a Phase I Biomarker study. sRSO(2) response may potentially be a biomarker to identify infants who are likely to develop NEC post-RBCT that needs to be validated in larger prospective "hypothesis-testing" randomised controlled trials.