Nucleated red blood cells and early EEG: predicting Sarnat stage and two year outcome

NRBC concentrations over time in neonates with moderate to severe neonatal encephalopathy with and without sentinel events

OBJECTIVE

To study the serum concentrations of nucleated red blood cells (NRBC) over time in neonates with moderate to severe neonatal encephalopathy (NE).

STUDY DESIGN

A retrospective cohort study with subjects subdivided into three groups: definite sentinel events (n = 52), probable sentinel events (n = 20) and no history of sentinel events (n = 63). Peak absolute NRBC and NRBC/100 WBC were compared between groups and with MRI Injury score, cord and admission pH/base deficit.

RESULTS

Absolute NRBC peaked at 24.05 h after birth (CI: 15.30-32.79), 17.56 h after birth (CI: 7.35-27.77), and 39.81 h after birth (CI: 28.73-50.89) in each respective group. The peak in absolute NRBC correlated with the severity of injury in the grey matter in group 2 and white matter in groups 1 and 2. Higher peak absolute NRBC value correlated to a lower admission ABG pH.

CONCLUSION

NRBC peak at 24 h after birth in neonates with sentinel events.

Diagnostic Value and Prognostic Significance of Nucleated Red Blood Cells (NRBCs) in Selected Medical Conditions

Nucleated red blood cells (NRBCs) are premature erythrocyte precursors that reside in the bone marrow of humans of all ages as an element of erythropoiesis. They rarely present in healthy adults' circulatory systems but can be found circulating in fetuses and neonates. An NRBC count is a cost-effective laboratory test that is currently rarely used in everyday clinical practice; it is mostly used in the diagnosis of hematological diseases/disorders relating to erythropoiesis, anemia, or hemolysis. However, according to several studies, it may be used as a biomarker in the diagnosis and clinical outcome prognosis of preterm infants or severely ill adult patients. This would allow for a quick diagnosis of life-threatening conditions and the prediction of a possible change in a patient's condition, especially in relation to patients in the intensive care unit. In this review, we sought to summarize the possible use of NRBCs as a prognostic marker in various disease entities. Research into the evaluation of the NRBCs in the pediatric population most often concerns neonatal hypoxia, the occurrence and consequences of asphyxia, and overall neonatal mortality. Among adults, NRBCs can be used to predict changes in clinical condition and mortality in critically ill patients, including those with sepsis, trauma, ARDS, acute pancreatitis, or severe cardiovascular disease.

Association Between Early EEG Background and Outcomes in Infants With Mild HIE Undergoing Therapeutic Hypothermia

BACKGROUND

Hypoxic-ischemic encephalopathy (HIE) occurs in 1-4:1000 live births. Although neonates with moderate-severe HIE have been studied over several decades, newborns with mild HIE remain understudied, including seizure occurrence, electroencephalography (EEG) characteristics, and outcome.

METHODS

We conducted a retrospective cohort study of neonates ≥35 weeks of gestation with mild HIE who underwent therapeutic hypothermia to correlate the early EEG background pattern with clinical course and outcomes.

RESULTS

Of the included 29 neonates, 10 infants had a moderately to severely abnormal EEG background and 19 had either a normal or a mildly abnormal background. Those with moderately to severely abnormal background also had more multiorgan dysfunction (90% vs 42%, P = 0.02) and a higher incidence of subdural and intraventricular hemorrhages (80% vs 26%, P = 0.02). The overall seizure incidence was 20.7% and was significantly higher in newborns with more severely abnormal background compared to neonates with less abnormal background (50% vs 5%; P = 0.01; relative risk, 9.5; 95% confidence interval, 1.28-70.6). Seizure onset was between 11 and 63 hours of life. Regardless of the EEG background pattern, seizures were brief with an overall low seizure burden. None of the newborns with normal or mildly abnormal background had a new onset of seizures after 24 hours of recording or developed epilepsy during infancy.

CONCLUSIONS

In neonates with mild HIE, early moderately to severely abnormal EEG background is common and strongly associated with an increased risk for seizures.

Multichannel EEG abnormalities during the first 6 hours in infants with mild hypoxic-ischaemic encephalopathy

BACKGROUND

Infants with mild HIE are at risk of significant disability at follow-up. In the pre-therapeutic hypothermia (TH) era, electroencephalography (EEG) within 6 hours of birth was most predictive of outcome. This study aims to identify and describe features of early EEG and heart rate variability (HRV) (<6 hours of age) in infants with mild HIE compared to healthy term infants.

METHODS

Infants >36 weeks with mild HIE, not undergoing TH, with EEG before 6 hours of age were identified from 4 prospective cohort studies conducted in the Cork University Maternity Services, Ireland (2003-2019). Control infants were taken from a contemporaneous study examining brain activity in healthy term infants. EEGs were qualitatively analysed by two neonatal neurophysiologists and quantitatively assessed using multiple features of amplitude, spectral shape and inter-hemispheric connectivity. Quantitative features of HRV were assessed in both the groups.

RESULTS

Fifty-eight infants with mild HIE and sixteen healthy term infants were included. Seventy-two percent of infants with mild HIE had at least one abnormal EEG feature on qualitative analysis and quantitative EEG analysis revealed significant differences in spectral features between the two groups. HRV analysis did not differentiate between the groups.

CONCLUSIONS

Qualitative and quantitative analysis of the EEG before 6 hours of age identified abnormal EEG features in mild HIE, which could aid in the objective identification of cases for future TH trials in mild HIE.

IMPACT

Infants with mild HIE currently do not meet selection criteria for TH yet may be at risk of significant disability at follow-up. In the pre-TH era, EEG within 6 hours of birth was most predictive of outcome; however, TH has delayed this predictive value. 72% of infants with mild HIE had at least one abnormal EEG feature in the first 6 hours on qualitative assessment. Quantitative EEG analysis revealed significant differences in spectral features between infants with mild HIE and healthy term infants. Quantitative EEG features may aid in the objective identification of cases for future TH trials in mild HIE.

Association of nucleated red blood cell count with mortality among neonatal intensive care unit patients

BACKGROUND

Nucleated red blood cells (nRBCs) are associated with adverse outcomes for pediatric and adult intensive care patients.

METHODS

The association between nRBC count and mortality was examined in an observational cohort of patients admitted to the neonatal intensive care unit from December 2015-December 2018.

RESULTS

Among the 1059 patients with at least one nRBC count obtained, 45 infants (4.2%) experienced in-hospital mortality prior to NICU discharge, the primary outcome measured in this study. Infants with any nRBC count >0 had a significantly higher risk of mortality (5.3% [45/849] vs. 0% [0/351], p < 0.001 by Fisher exact), and time to mortality decreased with higher nRBC counts (Spearman correlation -0.59, p < 0.001). The association between nRBC count and mortality remained significant even when restricting only to infants who were older than 7 days at time of nRBC count.

CONCLUSION

Among neonatal intensive care unit patients, including those >7 days old, nRBCs are associated with significantly elevated mortality risk. A prospective study to better characterize clinical co-variants is necessary to better establish the use of nRBCs as a predictor of mortality.

Emergence role of nucleated red blood cells in molecular response evaluation for chronic myeloid leukemia

Purpose

To investigate and evaluate the role of nucleated red blood cells (NRBCs) and other markers in predicting remission failure in chronic myeloid leukemia (CML) patients treated with imatinib.

Methods

Seventy-one CML patients with BCR-ABL(+) in bone marrow cells were selected for this study. Molecular response evaluations were done every three months according to the recommendations of European LeukemiaNet (ELN). Patients were defined as remission failure if BCR-ABL transcripts >10% after 6 months (T6), >1% after 12 months (T12), and >0.1% after 18 (T18) months of treatment. The logistic regression was used to determine the optimal cut-off point of each marker and test the association of marker level with remission failure.

Results

The median NRBC, white blood cells, blast cells, basophils, and platelets were declined parallel with the decreases of BCR-ABL transcripts in bone marrow cells after 6 months of treatment (P<0.001). In addition, NRBC was almost not found in the blood of patients who archived good response at T6, T12, and T18 time-points. Interestingly, patients with a high level of NRBC (cut-off: 0.003×10⁹/L) have higher BCR-ABL transcripts compared to others. The elevated NRBC at T6 (OR=6.49, P=0.042), T12 (OR=6.73, P=0.007), and T18 (OR=5.96, P=0.009) time-points was identified as an independent factor for the remission failure.

Conclusion

The results of this study showed that a high number of NRBC in peripheral blood of CML patients is associated with higher BCR-ABL transcripts in bone marrow cells. The elevated NRBC might serve as an independent marker for molecular remission failure in CML.

Neonatal Encephalopathy: Need for Recognition of Multiple Etiologies for Optimal Management

Neonatal encephalopathy (NE) is associated with high mortality and morbidity. Factors predisposing to NE can be antenatal, perinatal, or a combination of both. Antenatal maternal factors, familial factors, genetic predisposition, hypoxic ischemic encephalopathy, infections, placental abnormalities, thrombophilia, coagulation defects, and metabolic disorders all have been implicated in the pathogenesis of NE. At present, therapeutic hypothermia is the only treatment available, regardless of etiology. Recognizing the etiology of NE involved can also guide investigations such as metabolic and sepsis workups to ensure optimal management. Understanding the etiology of NE may allow the development of targeted adjunctive therapies related to the underlying mechanism and develop preventative strategies.

Biomarkers in neonatal hypoxic-ischemic encephalopathy-Review of the literature to date and future directions for research

The widespread introduction of therapeutic hypothermia as a standard of care in hypoxic-ischemic encephalopathy (HIE) has brought increasing pressure on clinicians to make an early and accurate assessment of the degree of hypoxic injury (HI) that has occurred and the severity of the encephalopathy that will ensue. No single blood-based marker is currently robust enough to detect significant HI or predict outcome. However, research in the field has been active in the last 10 years and we know that HIE is associated with predictable alterations in the expression of a number of inflammatory proteins, neuron-specific proteins, metabolite pathways, and microRNA. These alterations evolve quickly over the first hours and days of life. Predictive power varies depending on the timing of measurement of the biomarker, the sample type, and the case mix of the cohort examined. Combining clinical data with biochemical measurements is currently the most likely path toward improved detection and prediction of outcome in neonatal HIE.

A study of microRNAs from dried blood spots in newborns after perinatal asphyxia: a simple and feasible biosampling method

BACKGROUND

The potential of microRNAs (miRNAs) as bedside biomarkers in selecting newborns with hypoxic-ischemic encephalopathy (HIE) for neuroprotection has yet to be explored. Commonly, blood-based biomarker tests use plasma or serum which don't allow evaluation of both intracellular and extracellular changes.

METHODS

We describe a technique to extract and compare expression of miRNAs from a single small 6-mm-diameter dried blood spot (DBS) stored at room temperature with those from EDTA-blood, plasma, and urine. Three miRNAs (RNU6B, let7b, and miR-21) were quantified via extraction and quantitative RT-PCR performed from a DBS and compared with levels from EDTA-blood, plasma, and urine. Secondarily, candidate miRNAs let7b, miR-21, miR-29b, miR-124, and miR-155 in DBS were evaluated as potential biomarkers for HIE.

RESULTS

Candidate miRNAs were extractable in all biosamples from newborns, with the highest expression in DBS. There was a good correlation between miRNAs' levels in DBS and EDTA-blood at -80 °C. No significant difference was observed in the miRNA levels between the favorable and unfavorable outcome groups for babies with HIE.

CONCLUSION

DBS may be useful for studying the potential of miRNAs as biomarkers for brain injury.

Biomarkers of multiorgan injury in neonatal encephalopathy

Neonatal encephalopathy (NE) is a major contributor to neurodevelopmental deficits including cerebral palsy in term and near-term infants. The long-term neurodevelopmental outcome is difficult to predict with certainty in first few days of life. Multiorgan involvement is common but not part of the diagnostic criteria for NE. The most frequently involved organs are the heart, liver, kidneys and hematological system. Cerebral and organ involvement is associated with the release of organ specific biomarkers in cerebrospinal fluid, urine and blood. These biomarkers may have a role in the assessment of the severity of asphyxia and long-term outcome in neonates with NE.

Nucleated red blood cell counts: an early predictor of brain injury and 2-year outcome in neonates with hypoxic-ischemic encephalopathy in the era of cooling-based treatment

BACKGROUND

Raised nucleated red blood cell (NRBC) counts in neonates may indicate in utero hypoxia and brain damage.

OBJECTIVE

The study aimed to examine the use of NRBC counts as a predictor of brain injury and neurodevelopmental outcomes in neonates with hypoxic-ischemic encephalopathy (HIE) treated under current cooling-based strategy.

METHODS

Forty-three neonates with asphyxia between 2004 and 2010 were retrospectively investigated. Twenty neonates with moderate/severe HIE underwent hypothermia (HT), and 23 with mild HIE were treated in normothermia (NT). Neonates were divided into groups according to the presence of cerebral parenchymal lesions on magnetic resonance imaging (MRI) at 2 weeks after birth. All patients were followed-up neurologically for ⩾ 24 months. NRBC counts during the first 3 days were compared between groups.

RESULTS

Eleven HT (HT-N) and 21 NT (NT-N) neonates had normal MRI, and 9 HT (HT-L) and 2 NT (NT-L) neonates had parenchymal lesions. NRBC counts, both absolute and /100 white blood cells (WBC) counts, during the first 3 days in HT-L and NT-L were significantly higher than those in HT-N and NT-N, particularly within 6 hours after birth (HT-N: 502 [0-3060]/mm(3) vs HT-L: 2765 [496-6192]; 0 [0-3417] vs NT-L: 4384 [3978-4789], median [range]). Neonates with /100 white blood cells ⩾ 6/mm(3) and absolute NRBC counts ⩾ 1324/mm(3) within 6 hours of birth had high risks of abnormal MRIs and 2-year outcomes.

CONCLUSIONS

NRBC counts can predict brain injury and neurological outcomes in cooled and non-cooled asphyxiated neonates.

Predictors of neurological outcome in cooled neonates

BACKGROUND

We define clinical predictors of neurological outcome in neonates with hypoxic-ischemic encephalopathy undergoing hypothermia therapy.

METHODS

Twenty-one neonates who underwent selective head cooling between 2004 and 2010 and were followed neurologically for ≥ 24 months were investigated retrospectively. Patients were divided according to the neurological outcome at 2 years of age into group A (n = 11), patients with normal neurological function, and group B (n = 10), patients with neurological disabilities (n = 9) or those who died (n = 1). Predictors were determined by χ(2) and Mann-Whitney U-tests, anova, Spearman rank correlations and receiver-operator curves.

RESULTS

Group B showed higher average blood lactate levels during the first day, particularly at 24 h of life; lower day-3 cerebral blood flow resistance index; higher maximum dobutamine dose used; higher rate of thiamylal sodium used; more severe background electroencephalogram suppression during the first week (group A: 11/11 cases ≤ grade 3; group B: 7/9 cases at grade 4-5) and higher rate of cerebral lesions on magnetic resonance imaging in the second week (group A: 1/11 case; group B: 9/10 cases) than group A. The most useful predictor of poor prognosis was cerebral parenchymal lesions on magnetic resonance imaging with 90%, 90% and 90% of sensitivity, specificity and accuracy, followed by week-1 background electroencephalogram ≥ grade 4 with 70%, 100% and 85% and day-3 cerebral blood flow resistance index < 0.46 with 71%, 88% and 80%, respectively.

CONCLUSIONS

Prediction of post-cooling neurological outcome could be improved substantially by evaluating multiple factors.

Association of nucleated red blood cells and severity of encephalopathy in normothermic and hypothermic infants

AIM

To determine whether hypothermia alters the discriminative ability of postnatal nucleated red blood cells (NRBCs) to distinguish between mild and moderate/severely encephalopathic infants.

METHODS

A prospective cohort study recruited full-term neonates with hypoxic ischaemic encephalopathy (HIE) from 2003 to 2012 (prehypothermic and hypothermic eras). The NRBC count was analysed in the first 24 h in all infants and compared between normothermic and hypothermic cohorts. The severity of encephalopathy was categorized using both clinical Sarnat score and continuous multichannel EEG.

RESULTS

Eighty-six infants with HIE were included: in the normothermic group, 19 were clinically mild, 24 moderate/severe; in the hypothermic group, 22 were mild, 21 moderate/severe encephalopathy. NRBC count discriminated between mild and moderate/severe Sarnat scores in the normothermic group (p = 0.03) but not in the hypothermic group (p = 0.9). This change was due to a decrease in NRBCs among moderately encephalopathic infants in the hypothermic cohort.

CONCLUSION

Postnatal NRBCs distinguished between mild and moderate/severe encephalopathy in normothermic infants but not in infants undergoing therapeutic hypothermia. We advise caution when using postnatal blood samples to study diagnostic biomarkers for HIE without first analysing the potential impact of hypothermia upon these markers.