Transfusions and neurodevelopmental outcomes in extremely low gestation neonates enrolled in the PENUT Trial: a randomized clinical trial

The role of erythropoietin to prevent red blood cell transfusion in a 2018-2020 two-center cohort of preterm infants

BACKGROUND

Treatment with recombinant human erythropoietin (rHu-EPO) modestly prevented packed red blood cell transfusions (pRBCTs) in preterm infants in studies performed several years ago. In France, some neonatal units stopped using rHu-EPO, while others continued. The aim of this study was to explore the role of rHu-EPO in the prevention of pRBCTs in a recent cohort of preterm infants.

MATERIALS AND METHODS

Preterm infants who met rHu-EPO indications and were hospitalised between 2018 and 2020 in two neonatal units -one that did not use rHu-EPO and another that did- were eligible. Data about the neonatal history, rHu-EPO and iron treatments and pRBCT indications and volumes were collected. Infants exposed and not exposed to rHu-EPO were compared in univariate and multivariate analyses using backward logistic regression and Cox proportional hazards regression.

RESULTS

A total of 257 patients exposed to rHu-EPO and 285 patients who were not exposed were included. Three profiles emerged. In the infants with a gestational age <28 weeks, the cumulative pRBCT volume/kg was similar regardless of rHu-EPO exposure (mean difference -2.8 mL, 95% confidence interval -16.1, 10.5, p=0.68). In the infants born between 28 and 30 weeks, a late pRBCT was prevented in the rHu-EPO group (single pRBCT: no rHu-EPO 22.1% vs rHu-EPO 8%, p=0.003). However, rHu-EPO was not independently associated with avoidance of this pRBCT. Finally, the need for pRBCT was low in the infants born after 30 weeks of gestation, making rHu-EPO treatment futile. In contrast, early iron supplementation was revealed to be critical in preventing pRBCT.

DISCUSSION

No benefit of rHu-EPO in preventing pRBCT was observed in our cohort. The place of rHu-EPO in future requires careful consideration of the population concerned, adjustment of the therapeutic schedule and evolution of the indications for pRBCT.

Effect of Minimization of Early Blood Sampling Losses Among Extremely Premature Neonates: A Randomized Clinical Trial

OBJECTIVE

To evaluate the effect of blood sampling stewardship on transfusion requirements among infants born extremely preterm.

STUDY DESIGN

In this single-center, randomized controlled trial (RCT), infants born at <28 weeks of gestation and birth weight of <1000 g were randomized at 24 hours of age to two different blood sampling approaches: restricted sampling (RS) vs conventional sampling (CS). The stewardship intervention in the RS group included targeted reduction in blood sampling volume and frequency and point of care testing methods in the first 6 weeks after birth. Both groups received early recombinant erythropoietin from day three of age. Primary outcome was the rate of early red blood cell (RBC) transfusions in the first six postnatal weeks.

RESULTS

A total of 102 infants (mean gestational age: 26 weeks; birth weight: 756 g) were enrolled. Fidelity to the sampling protocol was achieved in 95% of the infants. Sampling losses in the first 6 weeks were significantly lower in the RS group (16.8 ml/kg vs 23.6 ml/kg, P < .001). The RS group had a significantly lower rate of early postnatal RBC transfusions (41% vs 73%, RR: 0.56 [0.39-0.81], P = .001). The hazard of needing a transfusion during neonatal intensive care unit (NICU) stay was reduced by 55% by RS. Mortality and neonatal morbidities were similar between the two groups.

CONCLUSION

Minimization of blood sampling losses by approximately one-third in the first 6 weeks after birth leads to substantial reduction in the early red blood cell transfusion rate in infants born extremely preterm and weighing <1000 g at birth.

TRIAL REGISTRATION

http://www.ctri.nic.in (CTRI/2020/01/022  964).

Banked term umbilical cord blood to meet the packed red blood cell transfusion needs of extremely-low-gestational-age neonates: a feasibility analysis

OBJECTIVES

To assess the feasibility of drawing, processing, safety-testing, and banking term umbilical cord blood to meet the packed red blood cell transfusion (RBC Tx) needs of extremely-low-gestational-age neonates (ELGANs).

DESIGN

(1) Retrospectively analyze all ELGANs RBC Tx over the past three years, (2) Estimate local cord blood availability, (3) Assess interest in this project, and implementation barriers, through stakeholder surveys.

RESULTS

In three years we cared for 266 ELGANs; 165 (62%) received ≥1 RBC Tx. Annual RBC Tx averaged 197 (95% CI, 152-243). If 10% of our 10,353 annual term births had cord blood drawn and processed, and half of those tested were acceptable for Tx, collections would exceed the 95th % upper estimate for need by >four-fold. Interest exceeded 97%. Identified barriers included FDA approval, training to collect cord blood, and cost.

CONCLUSION

RBC Tx needs of ELGANS could be met by local cord blood collection.

Identification of Genes Responding to Iron or Choline Treatment for Early-Life Iron Deficiency in the Male Rat Hippocampal Transcriptomes

BACKGROUND

Developmental iron deficiency (ID) is associated with long-term cognitive and affective behavioral impairments in humans. Preclinical studies have shown that developmental ID has short- and long-term effects on gene regulation. Prenatal choline supplementation partially rescues early-life ID-induced cognitive deficits in adult male rats.

OBJECTIVES

To identify acute and long-term changes in biological processes regulated by developmental ID and modifiable by choline.

METHODS

This study compares the hippocampal transcriptomes of postnatal day (P) 15 iron-deficient (acute) and P65 formerly ID (persistent) rats with or without prenatal choline treatment. Pregnant rats were fed an ID (4 mg/kg Fe) or iron-sufficient (IS) (200 mg/kg Fe) diet from gestational day (G) 2 to P7 with or without choline supplementation (5 g/kg choline) from G11 to G18. Hippocampi were collected from P15 or P65 offspring and analyzed for gene expression by RNA sequencing.

RESULTS

Developmental ID-induced changes suggested modified activity of oxidative phosphorylation and fatty acid metabolism. Prenatal choline supplementation induced robust changes in gene expression, particularly in iron-deficient animals, where it partially mitigated the early-life ID-dysregulated genes. Choline supplementation also altered the hippocampal transcriptome in the IS rats, with indications for both beneficial and adverse effects.

CONCLUSIONS

This study provided global assessments of gene expression regulated by iron and choline. Our new findings highlight genes responding to iron or choline treatments, including a potentially novel choline-regulated transporter (IPO7), with shared effects on neuroinflammation in the male rat hippocampus.

Darbepoetin alfa to reduce transfusion episodes in infants with haemolytic disease of the fetus and newborn who are treated with intrauterine transfusions in the Netherlands: an open-label, single-centre, phase 2, randomised, controlled trial

BACKGROUND

Up to 88% of infants with haemolytic disease of the fetus and newborn who are treated with intrauterine transfusions require erythrocyte transfusions after birth. We aimed to investigate the effect of darbepoetin alfa on the prevention of postnatal anaemia in infants with haemolytic disease of the fetus and newborn.

METHODS

We conducted an open-label, single-centre, phase 2 randomised controlled trial to evaluate the effect of darbepoetin alfa on the number of erythrocyte transfusions in infants with haemolytic disease of the fetus and newborn. All infants who were treated with intrauterine transfusion and born at 35 weeks of gestation or later at the Leiden University Medical Center, Leiden, Netherlands, were eligible for inclusion. Included infants were randomised by computer at birth to treatment with 10 μg/kg darbepoetin alfa subcutaneously once a week for 8 weeks or standard care (1:1 allocation, in varying blocks of four and six, with no stratification). Treating physicians and parents were not masked to treatment allocation, but the research team, data manager, and statistician were masked to treatment allocation during the process of data collection. The primary outcome was the number of erythrocyte transfusion episodes per infant from birth up to 3 months of life in the modified intention-to-treat population. This trial is registered with ClinicalTrials.gov (NCT03104426) and has been completed.

FINDINGS

Between Oct 31, 2017, and April 31, 2022, we recruited 76 infants, of whom 44 (58%) were randomly assigned to a treatment group (20 [45%] were allocated to receive darbepoetin alfa and 24 [55%] were allocated to receive standard care). Follow-up lasted 3 months and one infant dropped out of the trial before commencement of treatment. A significant reduction in erythrocyte transfusion episodes was identified with darbepoetin alfa treatment compared with standard care (median 1·0 [IQR 1·0-2·0] transfusion episodes vs 2·0 [1·3-3·0] transfusion episodes; p=0·0082). No adverse events were reported and no infants died during the study.

INTERPRETATION

Darbepoetin alfa reduced the transfusion episodes after intrauterine transfusion treatment for haemolytic disease of the fetus and newborn. Treatment with darbepoetin alfa or other types of erythropoietin should be considered as part of the postnatal treatment of severe haemolytic disease of the fetus and newborn.

FUNDING

Sanquin Blood Supply.

TRANSLATION

For the Dutch translation of the abstract see Supplementary Materials section.

New frontiers in neonatal red blood cell transfusion research

Red blood cell (RBC) transfusions are common in neonates requiring intensive care. Recent studies have compared restricted versus liberal transfusion guidelines, but limitations exist on evaluations of outcomes in populations that never required a transfusion compared to those receiving any transfusion. Although there are well-established risks associated with RBC transfusions, new data has emerged that suggests additional clinically relevant associations, including adverse neurodevelopmental outcomes, donor sex differences, and inflammation or immunosuppression. Further research is needed to delineate the magnitude of these risks and to further improve the safety of transfusions. The goal of this review is to highlight underappreciated, yet clinically important risks associated with neonatal RBC transfusions and to introduce several areas in which neonates may uniquely benefit from alterations in practice.

Impact of level of neonatal care on phlebotomy and blood transfusion in extremely low birthweight infants: a prospective, multicenter, observational study

Objectives

To explore the level of neonatal care on cumulative phlebotomy loss (cPL) and red cell transfusions in extremely low birthweight [ELBW; birthweight (BW) <1,000 g] infants, up to 40 weeks post-conceptual age (PCA). The secondary objective was to determine the associations between cPL and number of transfusions and between transfusions and hospital outcomes.

Methods

A prospective, comparative, observational study was conducted in two level IV and two level III neonatal intensive care units (NICUs) in Thailand. Daily cPL volume and number of blood tests were recorded. Descriptive data are reported as frequency and percentage for categorical variables and median [25th percentile (P25), 75th percentile (P75)] for continuous data according to the data distribution. A p-value <0.05 was considered statistically significant.

Results

210 ELBW infants were included; 99 and 111 were admitted to level IV and level III NICUs, respectively. Birth weight of level IV infants was lower 780.0 [660.0, 875.0] vs. 865.0 [723.0, 930.0] g; p < 0.001]. Initial group hematocrits were similar (43.1% vs. 44.0%, p = 0.47). cPL for each infant was 28.1 [16.5, 46.4] ml. Level IV infants had more tests (n = 89 [54, 195] vs. 59 [37, 88], p < 0.001). Counterintuitively, there was a lower cPL trend in level IV infants, but this was insignificant (19.6 [12.3, 52.3] vs. 28.9 [19.3, 45.3] ml; p = 0.06). The number of transfusions in both NICUs was similar 4 [2, 6], with a strong correlation between cPL and number of transfusions (r = 0.79, p < 0.001). Transfusions were significantly associated with bronchopulmonary dysplasia [BPD; adjusted RR (95% CI): 2.6 (1.2, 5.3), p = 0.01].

Conclusions

Level IV NICUs conducted more blood tests in ELBW infants without a difference in cPL, and number of transfusions. Cumulative PL correlated with number of transfusions and was associated with BPD risk. Minimizing cPL by point-of-care tests and restrictive transfusion criteria, may reduce need for transfusion.

Effect of Early Erythropoietin on Retinopathy of Prematurity: A Stratified Meta-Analysis

BACKGROUND

Recombinant human erythropoietin (rhEPO) lost its role in minimizing red blood cell transfusion in very preterm infants after it had been associated with severe retinopathy of prematurity (ROP). Previous systematic reviews did not stratify ROP by gestation and birth weight (BW).

OBJECTIVES

The aim of this study was to investigate the effect of early prophylactic rhEPO on ROP in a stratified meta-analysis of randomized controlled trials (RCTs).

METHODS

The databases EMBASE, MEDLINE, and the Cochrane Central Register of Controlled Trials were searched in January 2022 and complemented by citation searching. RCTs comparing early rhEPO treatment with no treatment or placebo were selected if they were published in a peer-reviewed journal and reported ROP outcomes. Previously unpublished data were requested from the study authors to allow stratified analyses by gestational age (GA) and BW. Data were extracted and analyzed using the standard methods of the Cochrane Neonatal Review Group. Pre-specified outcomes were "ROP stage ≥3" (primary outcome) and "any ROP."

RESULTS

Fourteen RCTs, comprising 2,040 infants of <29 weeks of GA, were included for meta-analysis. Data syntheses showed no effects of rhEPO on ROP stage ≥3 or on any ROP, neither in infants of <29 weeks GA, nor in infants of <1,000 g BW, nor in any GA strata. The risk ratio (95% confidence interval) for ROP stage ≥3 in infants of <29 weeks of GA was 1.13 (0.84, 1.53), p = 0.41 (quality of evidence: moderate).

CONCLUSIONS

The present meta-analysis detected no effects of early rhEPO on ROP in any comparison, but most stratified analyses were limited by low statistical power.

Predicting 2-year neurodevelopmental outcomes in extremely preterm infants using graphical network and machine learning approaches

Background

Infants born extremely preterm (<28 weeks' gestation) are at high risk of neurodevelopmental impairment (NDI) with 50% of survivors showing moderate or severe NDI when at 2 years of age. We sought to develop novel models by which to predict neurodevelopmental outcomes, hypothesizing that combining baseline characteristics at birth with medical care and environmental exposures would produce the most accurate model.

Methods

Using a prospective database of 692 infants from the Preterm Epo Neuroprotection (PENUT) Trial, which was carried out between December 2013 and September 2016, we developed three predictive algorithms of increasing complexity using a Bayesian Additive Regression Trees (BART) machine learning approach to predict both NDI and continuous Bayley Scales of Infant and Toddler Development 3rd ed subscales at 2 year follow-up using: 1) the 5 variables used in the National Institute of Child Health and Human Development (NICHD) Extremely Preterm Birth Outcomes Tool, 2) 21 variables associated with outcomes in extremely preterm (EP) infants, and 3) a hypothesis-free approach using 133 potential variables available for infants in the PENUT database.

Findings

The NICHD 5-variable model predicted 3-4% of the variance in the Bayley subscale scores, and predicted NDI with an area under the receiver operator curve (AUROC, 95% CI) of 0.62 (0.56-0.69). Accuracy increased to 12-20% of variance explained and an AUROC of 0.77 (0.72-0.83) when using the 21 pre-selected clinical variables. Hypothesis-free variable selection using BART resulted in models that explained 20-31% of Bayley subscale scores and AUROC of 0.87 (0.83-0.91) for severe NDI, with good calibration across the range of outcome predictions. However, even with the most accurate models, the average prediction error for the Bayley subscale predictions was around 14-15 points, leading to wide prediction intervals. Higher total transfusion volume was the most important predictor of severe NDI and lower Bayley scores across all subscales.

Interpretation

While the machine learning BART approach meaningfully improved predictive accuracy above a widely used prediction tool (NICHD) as well as a model utilizing NDI-associated clinical characteristics, the average error remained approximately 1 standard deviation on either side of the true value. Although dichotomous NDI prediction using BART was more accurate than has been previously reported, and certain clinical variables such as transfusion exposure were meaningfully predictive of outcomes, our results emphasize the fact that the field is still not able to accurately predict the results of complex long-term assessments such as Bayley subscales in infants born EP even when using rich datasets and advanced analytic methods. This highlights the ongoing need for long-term follow-up of all EP infants.

Funding

Supported by the National Institute of Neurological Disorders and StrokeU01NS077953 and U01NS077955.

Packed red blood cell transfusion in preterm infants

Premature infants commonly receive adult packed red blood cells (pRBCs) during their hospital stay. As adult erythrocytes differ substantially from those of preterm infants, transfusion of adult pRBCs into preterm infants can be considered inappropriate for the physiology of a preterm infant. An absence of standardisation of transfusion protocols makes it difficult to compare and interpret pertinent clinical data, as reflected by unclear associations between pRBC transfusion and complications related to prematurity, such as bronchopulmonary dysplasia, neurodevelopmental impairment, retinopathy of prematurity, or necrotising enterocolitis. The difficulty in interpreting clinical data is further increased by differences in study designs that either overestimate pRBC-associated complications of prematurity or have not yet been designed to directly link pRBC transfusions to their respective complications. Thus, neonatal transfusion practice has become an ongoing difficulty, in which differences in transfusion guidelines hinder the ability to generate comparable clinical data, and heterogeneity in clinical data prevents the implementation of standardised transfusion protocols. To overcome these issues, novel approaches with biochemical-clinical translational designs could enable clinicians to gather causal evidence instead of circumstantial correlation.

Current advances in transfusion medicine 2021: A critical review of selected topics by the AABB Clinical Transfusion Medicine Committee

BACKGROUND

Each year the AABB Clinical Transfusion Medicine Committee (CTMC) procures a synopsis highlighting new, important, and clinically relevant studies in the field of transfusion medicine (TM). This has been made available as a publication in Transfusion since 2018.

METHODS

CTMC members reviewed and identified original manuscripts covering TM-related topics published electronically (ahead-of-print) or in print from December 2020 to December 2021. Selection of publications was discussed at committee meetings and chosen based on perceived relevance and originality. Next, committee members worked in pairs to create a synopsis of each topic, which was then reviewed by additional committee members. The first and senior authors assembled the final manuscript. Although this synopsis is extensive, it is not exhaustive, and some articles may have been excluded or missed.

RESULTS

The following topics are included: blood products; convalescent plasma; donor collections and testing; hemoglobinopathies; immunohematology and genomics; hemostasis; patient blood management; pediatrics; therapeutic apheresis; and cell therapy.

CONCLUSIONS

This synopsis highlights and summarizes recent key developments in TM and may be useful for educational purposes.

Brain injury in preterm infants with surgical necrotizing enterocolitis: clinical and bowel pathological correlates

BACKGROUND

The objective of this study was to determine the risk factors and outcomes of white matter brain injury (WMBI) on magnetic resonance imaging (MRI) at term-equivalent age in infants with surgical necrotizing enterocolitis (NEC).

METHODS

This retrospective study compared clinical/pathological information between infants with and those without WMBI.

RESULTS

Out of 69 infants with surgical NEC, 17 (24.6%) had mild WMBI, 13 (18.8%) had moderate WMBI, and six (8.7%) had severe WMBI on the brain MRI. Several clinical factors (gestational age, more red blood cell (RBC) transfusions before NEC onset, pneumoperitoneum, earlier NEC onset age, postoperative ileus, acute kidney injury (AKI) by serum creatinine, postnatal steroids, hospital stay) and histopathological findings (necrosis, hemorrhage) had univariate associations with WMBI. Associations with RBC transfusion (odds ratio (OR) 23.6 [95% confidence interval (CI): 4.73-117.97]; p = 0.0001), age at NEC onset (OR 0.30 [95%CI: 0.11-0.84]; p = 0.021), necrosis (OR 0.10 [95%CI: 0.01-0.90]; p = 0.040), and bowel hemorrhage (OR 7.79 [95%CI: 2.19-27.72]; p = 0.002) persisted in multivariable association with grade 3-4 WMBI. The infants with WMBI had lower mean motor, cognitive, language scores, and higher ophthalmic morbidity at 2 years of age.

CONCLUSIONS

The WMBI was most likely associated with earlier NEC onset, higher RBC transfusions, and less necrosis and greater hemorrhage lesions on intestinal pathology in preterm infants with surgical NEC.

IMPACT

In preterm infants with surgical NEC, brain MRI showed injury in the white matter in 52%, gray matter in 10%, and cerebellar region in 30%. Preterm infants with severe WMBI (grade 3-4) had less necrosis and greater hemorrhagic lesions on histopathology of the bowel. Preterm infants with WMBI were more likely to have a more severe postoperative course, AKI, and longer length of hospitalization. Neuroprotective strategies to prevent brain injury in preterm infants with surgical NEC are needed with the goal of improving the neurodevelopmental outcomes.

Thresholds for blood transfusion in extremely preterm infants: A review of the latest evidence from two large clinical trials

There are two recently completed large randomized clinical trials of blood transfusions in the preterm infants most at risk of requiring them. Liberal and restrictive strategies were compared with composite primary outcome measures of death and neurodevelopmental impairment. Infants managed under restrictive guidelines fared no worse in regard to mortality and neurodevelopment in early life. The studies had remarkably similar demographics and used similar transfusion guidelines. In both, there were fewer transfusions in the restrictive arm. Nevertheless, there were large differences between the studies in regard to transfusion exposure with almost 3 times the number of transfusions per participant in the transfusion of prematures (TOP) study. Associated with this, there were differences between the studies in various outcomes. For example, the combined primary outcome of death or neurodevelopmental impairment was more likely to occur in the TOP study and the mortality rate itself was considerably higher. Whilst the reasons for these differences are likely multifactorial, it does raise the question as to whether they could be related to the transfusions themselves? Clearly, every effort should be made to reduce exposure to transfusions and this was more successful in the Effects of Transfusion Thresholds on Neurocognitive Outcomes (ETTNO) study. In this review, we look at factors which may explain these transfusion differences and the differences in outcomes, in particular neurodevelopment at age 2 years. In choosing which guidelines to follow, centers using liberal guidelines should be encouraged to adopt more restrictive ones. However, should centers with more restrictive guidelines change to ones similar to those in the studies? The evidence for this is less compelling, particularly given the wide range of transfusion exposure between studies. Individual centers already using restrictive guidelines should assess the validity of the findings in light of their own transfusion experience. In addition, it should be remembered that the study guidelines were pragmatic and acceptable to a large number of centers. The major focus in these guidelines was on hemoglobin levels which do not necessarily reflect tissue oxygenation. Other factors such as the level of erythropoiesis should also be taken into account before deciding whether to transfuse.

Prophylactic Erythropoietin for Neuroprotection in Very Preterm Infants: A Meta-Analysis Update

A meta-analysis update of randomized controlled trials investigating recombinant human erythropoietin suggests improved neurodevelopmental outcome in preterm infants. There was substantial heterogeneity, which could be ascribed to a single trial. Exclusion of this trial featuring a high risk of bias abolished heterogeneity and any effects of recombinant human erythropoietin treatment.