Erythrocyte Transfusion, Fetal Hemoglobin, Near Infrared Spectroscopy, Oxidative Stress in Neonates
Conditions
Keywords
fetal hemoglobin, erythrocyte transfusion, preterm neonates, peroxide, oxidative stress
Brief summary
Reactive oxygen species (ROS), which include peroxides, are generated in the human body as by-products of cellular metabolism. In small amounts, they fulfill important physiological functions. However, when produced in excess, they can damage cells and tissues. Extremely low gestation age neonates (ELGANs) are particularly vulnerable to such harmful effects because their antioxidant defense systems are immature, and they are exposed to increased ROS levels due to the oxygen therapy required after birth. Fetal hemoglobin (HbF), the primary oxygen carrier in the blood of newborns, plays a crucial role in this context. Compared with adult hemoglobin (HbA), it has a higher oxygen affinity and a more pronounced pseudoperoxidase activity, which helps protect organs during early development from peroxides. In addition to oxygen administration, blood transfusions can also contribute to increased ROS formation. Due to the immature hematopoietic system and the diagnostic blood sampling required, ELGANs frequently receive transfusions with adult red blood cell (A-RBC) concentrates. These lead to a rapid shift from HbF to HbA, further promoting the generation of ROS. Measuring ROS in blood is particularly challenging because these molecules are extremely short-lived. Consequently, reference values for newborns are lacking. Therefore, the investigators aim to establish reference ranges for one ROS, the peroxide in both term and preterm healty neonates from birth event onward and to assess the effects of A-RBC transfusions on this parameter in ELGANs. Furthermore, combining near-infrared spectroscopy-derived measurements of cerebral regional tissue oxygenation with peroxide assessments requiring only minimal blood volumes (0.5 mL per sample) will provide a more comprehensive and quantitatively robust understanding of the physiological changes induced by A-RBC transfusions in ELGANs. Excessive ROS exposure is considered a key risk factor for severe complications of prematurity, including brain injury, retinopathy, and chronic lung disease. With this project, investigators aim to improve the understanding of these risks and promote new evidence-based strategies in transfusion medicine. In the long term, transfusions with HbF-rich red blood cells derived from cord blood could help reduce ROS formation and provide effective protection for particularly vulnerable preterm infants.
Interventions
DIAGNOSTIC_TESTPeroxide analysis-TOC Omnignostica Forschungs GmbH
1\. Freshly prepared serum or EDTA plasma samples (total volume 0.5 ml) stored at room temperature for no longer than 30 minutes will be used for the peroxide analysis (TOC Omnignostica Forschungs GmbH, Höflein/Danube, Austria). If an immediate testing is not possible, samples will be stored at -20 °C for a maximum of two weeks.
DEVICENear Infrared Imaging
For NIRS measurements the t-NIRS 1 (Hamamatsu, Japan) will be used. This monitor uses a "continuous wave spatially resolved" technique and measures cerebral regional oxygen saturation (crSO2) non-invasively. A cerebral sensor will be placed and fixed with a CPAP cap on the left forehead. Duration of the transfusional measurement will be 8 hours (1h before, 6h during and 1h after the transfusion). Duration of post-transfusional measurement will be 1 hour and performed 12-24h and 6-8 days after the transfusion.
Sponsors
Medical University of Graz
Study design
Observational model
COHORT
Time perspective
PROSPECTIVE
Eligibility
Sex/Gender
ALL
Age
5 Years to 5 Months
Healthy volunteers
Yes
Inclusion criteria
Part A: * Neonates who are monitored on the NICU immediately after birth * Written parental informed consent Part B: * Term and preterm neonates admitted to the NICU for medical treatment * Age ad admission \<48 hours * Written parental informed consent Part C: * ELGANs 22(+5)-27(+6) weeks (days) gestation admitted to the NICU * Decision to conduct full life support * Written parental informed consent
Exclusion criteria
(Part A, B, C) * No decision to conduct full life support * No parental written informed consent * Congenital malformations * Family history of hemoglobinopathies (e.g. sickle cell anemia, thalassemia) * Fetal anemia requiring in-utero A-RBC transfusions
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Peroxide levels- Part A | Part A: From enrollment to the end of blood sampling from the placental part of the umbilical cord, at latest 30 minutes after birth. | Baseline peroxide levels in umbilical artery Baseline peroxide levels in umbilical vein |
| Peroxide levels- Part B | Part B: From enrollment until one week (7 days) after the admission to the neonatal intensive care unit. | Peroxide levels at admission (\<48h). Peroxide levels 48-72 h after admission. Peroxide levels 5-7 days after admission. |
| Peroxide levels- Part C | Part C: From enrollment to the postmenstrual age of 40+0 weeks. | FHbF and HbFc in pre-transfusional and post-transfusional routinely sampled blood samples in ELGANs undergoing A-RBC transfusions up to 8 days after each transfusion. Peroxide levels in pre-transfusional and post-transfusional blood samples, synchronized with routine blood draws in ELGANs undergoing A-RBC transfusions up to 8 days after each transfusion. Cerebral NIRS measurement of the regional tissue oxygenation: 1. Around an A-RBC transfusion: 1h before, 6h during and 1h after 2. 12-24 hours after an A-RBC transfusion: over 1h 3. 6-8 days following an A-RBC transfusion: over 1h |
Countries
Austria
Contacts
CONTACTEna Suppan, MD
CONTACTGerhard Cvirn, Associate Professor, PhD
PRINCIPAL_INVESTIGATOREna Suppan, MD
Divison of Neonatology, Department of Pediatrics, Medical University of Graz, Auenbruggerplatz 32, 8036 Graz, Austria
Outcome results
None listed