Reference values for nucleated red blood cells and serum lactate in very and extremely low birth weight infants in the first week of life

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.

Epigenome-wide association study of bronchopulmonary dysplasia in preterm infants: results from the discovery-BPD program

BACKGROUND

Bronchopulmonary dysplasia (BPD) is a lung disease in premature infants caused by therapeutic oxygen supplemental and characterized by impaired pulmonary development which persists into later life. While advances in neonatal care have improved survival rates of premature infants, cases of BPD have been increasing with limited therapeutic options for prevention and treatment. This study was designed to explore the relationship between gestational age (GA), birth weight, and estimated blood cell-type composition in premature infants and to elucidate early epigenetic biomarkers associated with BPD.

METHODS

Cord blood DNA from preterm neonates that went on to develop BPD (n = 14) or not (non-BPD, n = 93) was applied to Illumina 450 K methylation arrays. Blood cell-type compositions were estimated using DNA methylation profiles. Multivariable robust regression analysis elucidated CpGs associated with BPD risk. cDNA microarray analysis of cord blood RNA identified differentially expressed genes in neonates who later developed BPD.

RESULTS

The development of BPD and the need for oxygen supplementation were strongly associated with GA (BPD, p < 1.0E-04; O2 supplementation, p < 1.0E-09) and birth weight (BPD, p < 1.0E-02; O2 supplementation, p < 1.0E-07). The estimated nucleated red blood cell (NRBC) percent was negatively associated with birth weight and GA, positively associated with hypomethylation of the tobacco smoke exposure biomarker cg05575921, and high-NRBC blood samples displayed a hypomethylation profile. Epigenome-wide association study (EWAS) identified 38 (Bonferroni) and 275 (false discovery rate 1%) differentially methylated CpGs associated with BPD. BPD-associated CpGs in cord blood were enriched for lung maturation and hematopoiesis pathways. Stochastic epigenetic mutation burden at birth was significantly elevated among those who developed BPD (adjusted p = 0.02). Transcriptome changes in cord blood cells reflected cell cycle, development, and pulmonary disorder events in BPD.

CONCLUSIONS

While results must be interpreted with caution because of the small size of this study, NRBC content strongly impacted DNA methylation profiles in preterm cord blood and EWAS analysis revealed potential insights into biological pathways involved in BPD pathogenesis.

Peripheral Nucleated Red Blood Cells and Mortality in Critically Ill Children

The present retrospective cohort study examines whether there is an association between circulating nucleated red blood cells (nRBCs) and mortality in critically ill children. nRBCs are erythropoietic progenitor cells not found in peripheral blood of healthy adults and children beyond the neonatal period. The presence of circulating nRBCs is associated with poor prognosis in adults and neonates, though little is known about their significance in children. Admissions to both the general and cardiac pediatric intensive care unit at the Stollery Children's Hospital in Edmonton, Alberta between January 1, 2015 and December 31, 2017 were examined, and logistic regression was performed to ascertain the association between the peak absolute nRBC counts and in-hospital mortality in critically ill children. A total of 2065 admissions were included. The number of admissions with detectable nRBCs was 386 (prevalence: 13.9%), and the number of deaths was 93 (mortality: 4.5%). A statistically significant association was found between the absolute value of nRBC peak and intensive care unit mortality (odds ratio=1.37; 95% confidence interval: 1.13-1.67; P=0.002) as well as hospital mortality (odds ratio=1.38; 95% confidence interval: 1.12-1.70; P=0.003) independent of the Pediatric Index of Mortality 3 score (PIM3). This result warrants more attention to nRBC values and their potential clinical use.

The Reference Intervals of Whole Blood Copper, Zinc, Calcium, Magnesium, and Iron in Infants Under 1 Year Old

Trace elements are essential nutrients for the optimal growth, development, and health of infants, and the reference intervals (RIs) from these trace elements in the blood are very important for an accurate assessment of the status of the elements. In this study, blood samples from a total of 13,446 infants (7206 boys and 6240 girls) were used, and the copper (Cu), zinc (Zn), calcium (Ca), magnesium (Mg), and iron (Fe) in their blood were determined using atomic absorption spectrometry. After clearing the data and removing any outliers, the gender- and age-specific RIs obtained from the Cu, Zn, Ca, Mg, and Fe in the infants' blood were established according to the principles of the Clinical and Laboratory Standards Institute (CLSI) C28-A3. In the multivariable analysis, after making the relevant adjustments for the confounding factors, the age of the infants showed a significant positive correlation with the concentrations of Zn, Ca, Mg, and Fe found in the blood (p<0.01). Furthermore, there were obvious differences in the Cu, Zn, and Ca levels in the blood according to the gender of the infants (p<0.01). As infants are in the critical period of their growth and development, the gender- and age-specific RIs may provide helpful guidance for the nutritional status of the Cu, Zn, Ca, Mg, and Fe elements in the infants' blood.

Effects of small for gestational age status on mortality and major morbidities in ≤750 g neonates

BACKGROUND

Controversy exists regarding the impact of small for gestational age (SGA = birth weight < 10th percentile) status on mortality and major morbidities.

AIM

To assess the effects of SGA on mortality and major morbidities in ≤750 gram (g) neonates.

STUDY DESIGN

Retrospective (01/2005-12/2017), single center study at a tertiary NICU.

SUBJECTS

SGA neonates ≤ 750 g.

OUTCOME

Effect of SGA status on mortality and major morbidities.

RESULTS

183 infants were enrolled. 103 (56.3%) were non-SGA (mean gestational age 25 + 1 weeks ± 9.9 days, mean birth weight 662.6 ± 75.2 g), and 80 (43.7%) SGA (mean gestational age 26 + 6 weeks ± 14.0 days, mean birth weight 543.9 ± 114.7 g). Mortality was 24.1% (non-SGA: 30/103 (29.1%), SGA: 14/80 (17.5%); p = 0.08). Univariable logistic regression analysis revealed a significant protective effect of SGA status on pneumothoraces (OR 0.28, 95%-CI [0.11-0.69]), IVH (≥3) (OR 0.38; 95%-CI [0.15-0.67]), and seizures (OR 0.09, 95%-CI [0.01-0.76]), but NEC (≥2a) occurred more frequently in SGA neonates (p = 0.024). Multiple logistic regression analysis found SGA status to negatively influence ROP (≥3) (OR 2.87, 95%-CI [1.14-7.23]) and need for home monitoring (OR 2.38, 95%-CI [1.05-5.41]). Other major morbidities (IVH, PVL, RDS, BPD, NEC, FIP, sepsis, hearing impairment) and mortality rates were not significantly affected, but distinct organ-specific patterns were seen.

CONCLUSION

SGA had negative effects on the rate of severe ROP and the need for home monitoring, but other major morbidities as well as mortality rates were not significantly affected. In the future, it will be important to delineate underlying pathophysiological mechanisms that contribute to this pattern.

Nucleated red blood cells and serum lactate values on days 2 and 5 are associated with mortality and morbidity in VLBW infants

AIM

To correlate nucleated red blood cell counts and serum lactate concentrations on day 2 and 5 of life with morbidity and mortality in very low birth weight infants and to determine corresponding cutoff values.

METHODS

Retrospective analysis in a cohort of very low birth weight infants.

RESULTS

250 very low birth weight infants were included in this study. Gestational age ranged from 23 to 35 weeks (mean 29.04) and birth weight was 320-1500 g (mean 1047.9). 55 (22%) patients developed intraventricular hemorrhage, 55 (22%) bronchopulmonary dysplasia, 12 (4.8%) periventricular leukomalacia, 93 (37.2%) retinopathy of prematurity, and 1 (0.4%) necrotizing enterocolitis. Mortality rate was 25/250 (10%). Nucleated red blood cells and serum lactate on day 2 of life were associated with mortality (p < 0.001). Serum lactate on day 5 of life demonstrated an association with retinopathy of prematurity (p = 0.017), bronchopulmonary dysplasia (p = 0.044), and intraventricular hemorrhage (p < 0.001). Cutoff values predicting mortality were >89.5 nucleated red blood cells/100 leucocytes (sensitivity 68.2%, specificity 89.0%) and serum lactate concentrations >8.5 mmol/l (sensitivity 69.6%, specificity 93.5%) on day 2 of life.

CONCLUSION

We conclude that both nucleated red blood cell count and serum lactate concentration are valuable biomarkers in predicting important outcome parameters in very low birth weight infants.