Clinical Outcomes Related to the Gastrointestinal Trophic Effects of Erythropoietin in Preterm Neonates: A Systematic Review and Meta-Analysis

Strategies for the prevention of bronchopulmonary dysplasia

Bronchopulmonary dysplasia (BPD) is a common morbidity affecting preterm infants and is associated with substantial long-term disabilities. The pathogenesis of BPD is multifactorial, and the clinical phenotype is variable. Extensive research has improved the current understanding of the factors contributing to BPD pathogenesis. However, effectively preventing and managing BPD remains a challenge. This review aims to provide an overview of the current evidence regarding the prevention of BPD in preterm infants, offering practical insights for clinicians.

The Role of Erythropoietin in Preventing Anemia in the Premature Neonate

Recombinant human erythropoietin (rhEPO) treatment is an alternative to red blood cell (RBC) transfusions in neonates presenting anemia of prematurity (AOP). This study assesses the impact of early rhEPO administration on AOP (any stage) incidence, as well as the incidence of individual AOP stages and RBC transfusions. Out of 108 preterm neonates, 49 were administered rhEPO and compared to the remaining group using univariate and multivariate analyses. Univariately, gestational age (GA), birth weight (BW), hemoglobin (Hb), hematocrit (HCT), RBC levels, and iron administration were significantly associated with AOP (p < 0.05 each); however, only the latter remained significant following multivariate analysis (AOR: 2.75, 95% CI, 1.06-7.11). Multinomial analysis revealed rhEPO treatment was associated with a near three-fold reduction in moderate AOP incidence (OR: 0.36, 95% CI, 0.15-0.89). Furthermore, ANCOVA revealed positive correlations between rhEPO administration and 21-day Hb (p < 0.01), HCT (p < 0.05), and EPO (p < 0.001) levels. The results confirm previously reported benefits of rhEPO treatment, such as reduced moderate AOP incidence and increased Hb, HCT, and serum EPO levels.

Enteral administration of a simulated amniotic fluid in preventing feeding intolerance in very low birthweight neonates: A randomized controlled trial

OBJECTIVES

Feeding intolerance (FI) is a common finding in preterm neonates. Enteral administration of different forms of amniotic fluid (AF) has been tried for treating FI in high-risk neonates. Simulated amniotic fluid (SAF) is a solution with a similar electrolyte composition to human AF. The aim of this study was to examine whether enteral administration of SAF would improve feeding tolerance in very low birthweight (VLBW) neonates.

METHODS

Forty VLBW neonates were randomized to either SAF or placebo (total daily dose 20 mL/kg/d^-1 divided every 3 h) to their milk for a maximum of 7 d. Neonates with major congenital anomalies, those in whom early feeding was contraindicated, and those treated with parental erythropoietin and/or human granulocyte stimulating factor were excluded. The primary outcome was the total amount of enteral feeds reached by day 7. Secondary outcomes were incidence of FI and necrotizing enterocolitis (NEC). Study intervention was stopped on completing 7 d, reaching enteral feeds of 100 mL/kg/d^-1, or the appearance of any sign of FI or NEC.

RESULTS

All neonates tolerated the test solution well. The SAF group reached significantly larger volume and higher calories on days 3 and 7 (P < 0.05 for all). No statistical differences were seen between the two groups in incidence of FI (P = 0.311), NEC (P = 0.429), mortality (P = 0.632), length of stay (P = 0.744), or weight gain on day 10 (P = 0.389). Baseline hematologic parameters showed no statistical differences before or after enteral administration (P > 0.05).

CONCLUSION

Results of the present study demonstrated that SAF solution might improve feeding tolerance in VLBW babies without evidence of its systemic absorption. Larger multicenter randomized studies are recommended.

Erythropoietin Reduces Death and Neurodevelopmental Impairment in Neonatal Hypoxic-Ischemic Encephalopathy

Purpose: Erythropoietin (EPO) is a promising neuroprotective drug. We investigated whether EPO has beneficial effects on neurodevelopmental outcomes in infants with hypoxic-ischemic encephalopathy (HIE).Methods: We retrospectively reviewed the data of 56 infants with HIE born at or after 35 weeks of gestation who were admitted to Inha University Hospital between 2012 and 2021. Patients were divided into two groups based on EPO use and compared. In the EPO group, patients were administered 1,000 U/kg of EPO on days 1, 2, 3, 5, and 7, starting within 24 hours after birth. The primary outcome was death or neurodevelopmental impairment (NDI) at the age of 12 months.Results: EPO was administered to 38 infants, and 18 did not receive EPO. Only 37.5% of patients with HIE (21/56) and 60% of patients with moderate-to-severe HIE (21/35) received therapeutic hypothermia. Among all patients with HIE, death or NDI (21.1 % vs. 50.0%; odds ratio [OR], 0.09; 95% confidence interval [CI], 0.01 to 0.78; P=0.029) and brain injury on imaging (42.1% vs. 83.3%; OR, 0.16; 95% CI, 0.03 to 0.92; P=0.040) were significantly lower in the EPO group than in the control group. Among patients with moderate-to-severe HIE, brain injury on imaging (54.2% vs. 90.9%; OR, 0.04; 95% CI, 0.002 to 0.700; P=0.027) was significantly lower in the EPO group than in the control group.Conclusion: EPO administration significantly reduced mortality and NDI in infants with HIE. EPO can be considered an adjunctive therapeutic agent for neonatal HIE.

Early erythropoietin for preventing necrotizing enterocolitis in preterm neonates - an updated meta-analysis

Previous systematic reviews suggest reduction in necrotizing enterocolitis (NEC) among preterm infants supplemented with erythropoietin (EPO). We aimed to update our 2018 systematic review in this field considering the evidence accumulated over the last 3 years. Randomized controlled trials (RCTs) reporting the effect of early EPO supplementation vs placebo/no EPO supplementation on any stage NEC in preterm infants were included. Fixed effect model was used for meta-analysis. Trial sequential analysis (TSA) was conducted to verify the effects of EPO on NEC after accounting for repeated significance testing. A total of 22 RCTs (n = 5359) were included, of which six were new (n = 2541 additional preterm infants) in comparison to our previous systematic review. EPO significantly decreased the risk of any stage NEC (232/2669 (8.7%) vs 313/2690 (11.6%); RR: 0·76; TSA adjusted 95% CI (0·64, 0·90); p = 0·0008, number needed to treat (NNT) = 34). The risk of definite NEC (≥ Stage II) was also significantly reduced by EPO administration (105/2219 (4.7%) vs 141/2246 (6.3%); RR: 0.77; 95% CI (0.61, 0.98); p = 0.03, NNT: 62). However, the results for definite NEC were no longer significant on sensitivity analyses that included (a) only double-blind RCTs and (b) only prospectively registered trials. The quality of evidence was deemed moderate-to-low for the reported outcomes.

CONCLUSION

There is moderate to low-quality evidence that early prophylactic EPO reduces any stage and ≥ Stage II NEC in preterm neonates. Prospectively registered, adequately powered, double-blind RCTs are required to confirm these findings.

WHAT IS KNOWN

• Experimental studies have shown that erythropoietin (EPO) has gastrointestinal trophic effects. • Systematic reviews have shown that early treatment with EPO may decrease the risk of gut injury in preterm or low birth weight infants.

WHAT IS NEW

• Early EPO supplementation significantly reduced the incidence of any stage NEC and definite NEC in preterm infants < 34 weeks of gestation. • EPO had no significant effect on definite NEC in the analyses that included only double-blinded and prospectively registered RCTs. How might it impact clinical practice in the foreseeable future? • Early prophylactic EPO can be recommended for NEC prevention if its benefits are consistently demonstrated in adequately powered randomized trials with a low risk of bias.

Erythropoietin for preventing bronchopulmonary dysplasia in preterm infants: A systematic review and meta-analysis

BACKGROUND

Recombinant erythropoietin (rEPO) has erythropoiesis and anti-inflammatory properties that might help reduce lung injury in preterm infants.

OBJECTIVE

To conduct a systematic review and meta-analysis to evaluate the possible role of rEPO in altering the risk of bronchopulmonary dysplasia (BPD).

METHODS

PubMed, EMBASE, Web of Science, and the Cochrane Library databases were searched to identify randomized controlled trials (RCTs) that evaluated the effects of rEPO for the prevention of BPD in preterm infants.

RESULTS

Fourteen studies (3199 infants) were included. Our results could not demonstrate a significant effect of rEPO on the incidence of BPD36 (risk ratio [RR]: 0.97, 95% confidence interval [CI]: 0.87-1.09, p = 0.63, I²  = 0, 12 RCTs, high-quality evidence), BPD28 (RR: 1.28, 95% CI: 0.91-1.79, p = 0.15, I²  = 17%, three RCTs, low-quality evidence) and oxygen dependence days. The test for subgroup analysis by administration route of rEPO showed similar outcomes above. Some of the included trials reported a significant effect of intravenous rEPO on reduction of sepsis (RR: 0.82, 95% CI: 0.70-0.96, p = 0.01, I²  = 0, high-quality evidence) and any stage necrotizing enterocolitis (NEC) (RR: 0.75, 95% CI: 0.59-0.94, p = 0.01, I²  = 0, moderate-quality evidence). The incidence of mortality and stage II or higher NEC was comparable in rEPO and control infants.

CONCLUSION

Our results suggest that rEPO does not affect the risk of developing BPD in preterm infants. Adequately powered RCTs are required to further confirm these findings.

Pharmacotherapy in Bronchopulmonary Dysplasia: What Is the Evidence?

Bronchopulmonary Dysplasia (BPD) is a multifactorial disease affecting over 35% of extremely preterm infants born each year. Despite the advances made in understanding the pathogenesis of this disease over the last five decades, BPD remains one of the major causes of morbidity and mortality in this population, and the incidence of the disease increases with decreasing gestational age. As inflammation is one of the key drivers in the pathogenesis, it has been targeted by majority of pharmacological and non-pharmacological methods to prevent BPD. Most extremely premature infants receive a myriad of medications during their stay in the neonatal intensive care unit in an effort to prevent or manage BPD, with corticosteroids, caffeine, and diuretics being the most commonly used medications. However, there is no consensus regarding their use and benefits in this population. This review summarizes the available literature regarding these medications and aims to provide neonatologists and neonatal providers with evidence-based recommendations.

The effects of IGF-1 and erythropoietin on apoptosis and telomerase activity in necrotizing enterocolitis model

BACKGROUND

Apoptosis that occurs after hypoxia/reoxygenation (H/R) has an important role in the pathogenesis of necrotizing enterocolitis (NEC). Telomerase activity, showing the regeneration capacity, may also be important in the recovery process. Therefore, we aimed to investigate the effects of insulin-like growth factor-1 (IGF-1) and erythropoietin (EPO) on apoptosis and telomerase activity in an H/R model.

METHODS

Young mice were divided into four groups each containing ten Balb/c mice. Group 1 (H/R) were exposed to H/R; group 2 and group 3 were pretreated with IGF-1 and EPO, respectively, for 7 days before H/R. Group 4 served as control. Intestinal injury was evaluated by histological scoring and assessment of apoptosis was performed by terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) test. Proapoptotic and antiapoptotic gene expressions and telomerase activity were analyzed by real-time PCR.

RESULTS

IGF-1- and EPO-treated animals had decreased histological damage and apoptosis, confirmed by TUNEL test and caspase activity. Telomerase activity was increased in these animals in addition to increased expression of antiapoptotic genes. However, proapoptotic gene expressions were not statistically different.

CONCLUSIONS

The protective effects of IGF-1 and EPO in H/R damage may be through increased expression of antiapoptotic genes and increased telomerase activity, especially for IGF-1.

IMPACT

This is a comprehensive study measuring various variables, namely IGF-1, EPO, apoptosis, apoptotic and antiapoptotic genes, and telomerase activity in the NEC model. The intestinal protective effects of IGF-1 and EPO in H/R damage may occur through increased expression of antiapoptotic genes and increased telomerase activity. To the best of our knowledge, telomerase activity has not been investigated in the NEC model before. Regarding our results, novel strategies may be implemented for the early definitive diagnosis, robust preventive measures, and effective treatment modalities for NEC.

Enteral Feeding Interventions in the Prevention of Necrotizing Enterocolitis: A Systematic Review of Experimental and Clinical Studies

Necrotizing enterocolitis (NEC), which is characterized by severe intestinal inflammation and in advanced stages necrosis, is a gastrointestinal emergency in the neonate with high mortality and morbidity. Despite advancing medical care, effective prevention strategies remain sparse. Factors contributing to the complex pathogenesis of NEC include immaturity of the intestinal immune defense, barrier function, motility and local circulatory regulation and abnormal microbial colonization. Interestingly, enteral feeding is regarded as an important modifiable factor influencing NEC pathogenesis. Moreover, breast milk, which forms the currently most effective prevention strategy, contains many bioactive components that are known to support neonatal immune development and promote healthy gut colonization. This systematic review describes the effect of different enteral feeding interventions on the prevention of NEC incidence and severity and the effect on pathophysiological mechanisms of NEC, in both experimental NEC models and clinical NEC. Besides, pathophysiological mechanisms involved in human NEC development are briefly described to give context for the findings of altered pathophysiological mechanisms of NEC by enteral feeding interventions.

Sustained low-dose prophylactic early erythropoietin for improvement of neurological outcomes in preterm infants:A systematic review and meta-analysis

The aim of this meta-analysis was conducted to assess the effects of different doses of prophylactic rhEPO on neurodevelopmental outcomes and provide reference for rational drug use. The primary outcome was the number of infants with a Mental Developmental Index (MDI) <70 on the Bayley Scales of Infant Development. Five RCTs, comprising 2282 infants, were included in this meta-analysis. Overall, prophylactic rhEPO administration reduced the incidence of infants with an MDI <70, with an odds ratio (95% confidence interval) of 0.55 (0.38-0.79), P <0.05. The low-dose rhEPO subgroup was superior to the placebo subgroup, with an OR (95% CI) of 0.47 (0.25-0.87), P <0.05. However, high-dose rhEPO subgroup had no significant impact on MDI <70 in infants <28 weeks' gestational age. The definitions of the secondary outcome showed that there was no significant effect of rhEPO on cerebral palsy. For neonatal complications, although four studies showed that there were no differences in the pooled results of BPD and ICH events between rhEPO treatment and placebo, the ICH events were significantly lower in the low-dose rhEPO (OR 0.36; 95% CI 0.23-0.59). In addition, in the pooled results of NEC and ROP events, there were significant differences between the two groups (OR 0.63; 95% CI 0.43-0.93) (OR 0.80; 95% CI 0.65-0.98). And the NEC events were significantly lower in the low-dose rhEPO (OR 0.45; 95% CI 0.27-0.73). Sustained low-dose prophylactic early erythropoietin might be more superior than high-dose for improvement of neurological outcomes and several neonatal complications in preterm infants.

Use of GRADE in evidence syntheses published in high-impact-factor nutrition journals: A methodological survey

OBJECTIVE

To identify and describe the use of the GRADE approach for rating the certainty of evidence in nutrition systematic reviews (SRs).

STUDY DESIGN AND SETTING

We systematically searched for SRs using GRADE that were published between 2015 and 2019 in the 10 "nutrition" journals with the highest impact factor according to the JCR 2018.

RESULTS

Out of 800 SRs, 55 SRs of randomized control trials (RCTs) and/or nonrandomized studies (NRSs) used GRADE. Forty-seven SRs (5.9%) rated the outcome specific certainty of evidence (n = 36 in 2018/2019). We identified a total of 465 certainty of evidence outcome ratings (n = 335 RCT ratings), ranging from very-low (28.8%) to low (41%), moderate (26.5%), and high (3.7%). Very-low and high certainty of evidence ratings accounted for 61.4% and 0.8% of ratings in SRs of NRSs, compared to 16.1% and 4.8% in SRs of RCTs. Certainty of evidence was downgraded mostly for risk of bias (37.8%) and imprecision (33%) in SRs of RCTs and for imprecision (32.7%), risk of bias (29.4%) and inconsistency (29%) in SRs of NRSs.

CONCLUSION

Our study suggests a need for directing more attention toward strengthening acceptance of GRADE as well as building knowledge of the GRADE methodology in nutrition evidence synthesis.

Effect of enteral erythropoietin on feeding-related complications in preterm newborns: A pilot randomized controlled study

BACKGROUND AND STUDY AIMS

To evaluate the effects of enteral administration of recombinant human erythropoietin (rhEPO) on feeding-related complications in preterm infants.

PATIENTS AND METHODS

This double-blind, randomized controlled pilot study enrolled 120 preterm infants born ≤ 32 weeks' gestation who were admitted to the neonatal intensive care unit in a tertiary hospital; 60 patients randomly received recombinant human erythropoietin while the other 60 received placebo. Newborns who underwent cardiopulmonary resuscitation, infants with genetic syndromes, infants with inborn errors of metabolism, infants with major congenital or acquired gastrointestinal tract malformations, infants with previous use of parenteral growth factors such as recombinant human erythropoietin and granulocyte-macrophage colony-stimuating factor (GM-CSF) and infants previously treated with intravenous immunoglobulin were excluded. Overall, 48 patients withdrew from the study because of intravenous haematopoietic growth factor intake or death before treatment was completed. A total of 72 preterm infants remained in the study: 36 preterm infants in the erythropoietin (EPO) group, and 36 preterm infants in the placebo group. The day that enteral feeding was successfully started, the time to establishing one-half, two-thirds, and full enteral feedings (reaching at least 150 mL/kg/day), the number of episodes of feeding intolerance, the time to regain birth weight and the incidence of necrotizing enterocolitis (NEC) were recorded.

RESULTS

Both groups showed no significant difference in the time to achieve one-half, two-thirds, or full enteral feeding, no signs of feeding intolerance, and no cases of NEC were recorded.

CONCLUSION

Enteral erythropoietin does not appear to affect feeding intolerance or NEC incidence.

Treatment of Neonatal Hypoxic-Ischemic Encephalopathy with Erythropoietin Alone, and Erythropoietin Combined with Hypothermia: History, Current Status, and Future Research

Perinatal hypoxic-ischemic encephalopathy (HIE) remains a major cause of morbidity and mortality. Moderate hypothermia (33.5 °C) is currently the sole established standard treatment. However, there are a large number of infants for whom this therapy is ineffective. This inspired global research to find neuroprotectants to potentiate the effect of moderate hypothermia. Here we examine erythropoietin (EPO) as a prominent candidate. Neonatal animal studies show that immediate, as well as delayed, treatment with EPO post-injury, can be neuroprotective and/or neurorestorative. The observed improvements of EPO therapy were generally not to the level of control uninjured animals, however. This suggested that combining EPO treatment with an adjunct therapeutic strategy should be researched. Treatment with EPO plus hypothermia led to less cerebral palsy in a non-human primate model of perinatal asphyxia, leading to clinical trials. A recent Phase II clinical trial on neonatal infants with HIE reported better 12-month motor outcomes for treatment with EPO plus hypothermia compared to hypothermia alone. Hence, the effectiveness of combined treatment with moderate hypothermia and EPO for neonatal HIE currently looks promising. The outcomes of two current clinical trials on neurological outcomes at 18-24 months-of-age, and at older ages, are now required. Further research on the optimal dose, onset, and duration of treatment with EPO, and critical consideration of the effect of injury severity and of gender, are also required.

Nutritional interventions to reduce rates of infection, necrotizing enterocolitis and mortality in very preterm infants

Observational studies demonstrating reduced rates of infections, necrotizing enterocolitis (NEC), and mortality in preterm infants fed their own mother's milk, as opposed to formula, have prompted endeavors to achieve similar effects with the right choice of food and food additives. In a systematic review of meta-analyses and randomized controlled trials (RCTs), we considered nutritional interventions aimed at reducing the rates of infections, NEC, or mortality in very preterm infants. The overall effects of particular interventions were presented as risk ratios with 95% confidence intervals. In RCTs, pasteurized human donor milk, as opposed to formula, reduced NEC but not infections or mortality. No differences emerged between infants receiving human or bovine milk-based fortifiers. Pooled data of small trials and a recent large RCT suggested that bovine lactoferrin reduced rates of fungal sepsis without impact on other infections, NEC, or mortality. Pooled data of RCTs assessing the use of prebiotic oligosaccharides found reduced infection but not mortality. Enteral L-glutamine (six RCTs) lowered infection rates, and enteral L-arginine (three RCTs) reduced NEC. A meta-analysis sensitivity approach found multiple-strain (but not single-strain) probiotics to be highly effective in reducing NEC and mortality. Thus, selected food components may help to improve outcomes in preterm infants.