Decreased ferritin levels, despite iron supplementation, during erythropoietin therapy in anaemia of prematurity

High Prevalence of Iron Deficiency Despite Standardized High-Dose Iron Supplementation During Recombinant Erythropoietin Therapy in Extremely Low Gestational Age Newborns

OBJECTIVE

To assess the effects of protocolized recombinant human erythropoietin (r-HuEPO) therapy and standardized high dose iron supplementation on hematologic and iron status measures in a cohort of extremely low gestational age newborns (ELGANs).

STUDY DESIGN

Charts of extremely low gestational age newborns admitted from 2006 to 2016 and who had received r-HuEPO per neonatal intensive care unit protocol were reviewed. The r-HuEPO was started at a dose of 900 IU/kg per week after 7 days of age and continued until 35 weeks postmenstrual age. Oral iron supplementation at 6-12 mg/kg per day was used to maintain a transferrin saturation of >20% during r-HuEPO treatment. Data on demographic features, hematologic and iron panel indices, red blood cell transfusions, and clinical outcomes were collected. Quartile groups were created based on serum ferritin levels at the conclusion of the r-HuEPO treatment and the quartiles were compared.

RESULTS

The cohort included 116 infants with mean gestational age 25.8 ± 1.5 weeks and birth weight 793 ± 174.1 g. The r-HuEPO promoted erythropoiesis as indicated by increasing hemoglobin, hematocrit, and reticulocyte count. Serum ferritin decreased over time and was ≤75 ng/mL in 60.2% of infants at the conclusion of r-HuEPO therapy; 87% received packed red blood cell transfusions. Transfusion volume, total iron intake, total iron binding capacity, and transferrin concentration differed among infants in the different serum ferritin quartiles (P < .05).

CONCLUSIONS

In extremely low gestational age newborns, r-HuEPO therapy promoted erythropoiesis. Despite a biomarker-based standardized high-dose iron supplementation, the majority of infants had evidence of iron deficiency to a degree that is associated with reduced brain function.

Late erythropoiesis-stimulating agents to prevent red blood cell transfusion in preterm or low birth weight infants

BACKGROUND

Preterm infants have low plasma levels of erythropoietin (EPO), providing a rationale for the use of erythropoiesis-stimulating agents (ESAs) to prevent or treat anaemia. Darbepoetin (Darbe) and EPO are currently available ESAs.

OBJECTIVES

To assess the effectiveness and safety of late initiation of ESAs, between eight and 28 days after birth, in reducing the use of red blood cell (RBC) transfusions in preterm or low birth weight infants.

SEARCH METHODS

We used the standard search strategy of Cochrane Neonatal to search the Cochrane Central Register of Controlled Trials (CENTRAL 2018, Issue 5), MEDLINE via PubMed (1966 to 5 June 2018), Embase (1980 to 5 June 2018), and CINAHL (1982 to 5 June 2018). We searched clinical trials databases, conference proceedings, and the reference lists of retrieved articles for randomised controlled trials and quasi-randomised trials.

SELECTION CRITERIA

Randomised or quasi-randomised controlled trials of late initiation of EPO treatment (started at ≥ eight days of age) versus placebo or no intervention in preterm (< 37 weeks) or low birth weight (< 2500 grams) neonates.

DATA COLLECTION AND ANALYSIS

We performed data collection and analyses in accordance with the methods of the Cochrane Neonatal Review Group. We used the GRADE approach to assess the quality of the evidence.

MAIN RESULTS

We include 31 studies (32 comparisons) randomising 1651 preterm infants. Literature searches in 2018 identified one new study for inclusion. No new on-going trials were identified and no studies used darbepoetin. Most included trials were of small sample size. The meta-analysis showed a significant effect on the use of one or more RBC transfusions (21 studies (n = 1202); typical risk ratio (RR) 0.72, 95% confidence interval (CI) 0.65 to 0.79; typical risk difference (RD) -0.17, 95% CI -0.22 to -0.12; typical number needed to treat for an additional beneficial outcome (NNTB) 6, 95% CI 5 to 8). There was moderate heterogeneity for this outcome (RR I² = 66%; RD I² = 58%). The quality of the evidence was very low. We obtained similar results in secondary analyses based on different combinations of high/low doses of EPO and iron supplementation. There was no significant reduction in the total volume (mL/kg) of blood transfused per infant (typical mean difference (MD) -1.6 mL/kg, 95% CI -5.8 to 2.6); 5 studies, 197 infants). There was high heterogeneity for this outcome (I² = 92%). There was a significant reduction in the number of transfusions per infant (11 studies enrolling 817 infants; typical MD -0.22, 95% CI -0.38 to -0.06). There was high heterogeneity for this outcome (I² = 94%). Three studies including 404 infants reported on retinopathy of prematurity (ROP) (all stages or stage not reported), with a typical RR 1.27 (95% CI 0.99 to 1.64) and a typical RD of 0.09 (95% CI -0.00 to 0.18). There was high heterogeneity for this outcome for both RR (I² = 83%) and RD (I² = 82%). The quality of the evidence was very low.Three trials enrolling 442 infants reported on ROP (stage ≥ 3). The typical RR was 1.73 (95% CI 0.92 to 3.24) and the typical RD was 0.05 (95% CI -0.01 to 0.10). There was no heterogeneity for this outcome for RR (I² = 18%) but high heterogeneity for RD (I² = 79%). The quality of the evidence was very low.There were no significant differences in other clinical outcomes including mortality and necrotising enterocolitis. For the outcomes of mortality and necrotising enterocolitis, the quality of the evidence was moderate. Long-term neurodevelopmental outcomes were not reported.

AUTHORS' CONCLUSIONS

Late administration of EPO reduces the use of one or more RBC transfusions, the number of RBC transfusions per infant (< 1 transfusion per infant) but not the total volume (mL/kg) of RBCs transfused per infant. Any donor exposure is likely not avoided as most studies included infants who had received RBC transfusions prior to trial entry. Late EPO does not significantly reduce or increase any clinically important adverse outcomes except for a trend in increased risk for ROP. Further research of the use of late EPO treatment, to prevent donor exposure, is not indicated. Research efforts should focus on limiting donor exposure during the first few days of life in sick neonates, when RBC requirements are most likely to be required and cannot be prevented by late EPO treatment. The use of satellite packs (dividing one unit of donor blood into many smaller aliquots) may reduce donor exposure.

Late erythropoiesis-stimulating agents to prevent red blood cell transfusion in preterm or low birth weight infants

BACKGROUND

Preterm infants have low plasma levels of erythropoietin (EPO), providing a rationale for the use of erythropoiesis-stimulating agents (ESAs) to prevent or treat anaemia. Darbepoetin (Darbe) and EPO are currently available ESAs.

OBJECTIVES

To assess the effectiveness and safety of late initiation of ESAs, between eight and 28 days after birth, in reducing the use of red blood cell (RBC) transfusions in preterm or low birth weight infants.

SEARCH METHODS

We used the standard search strategy of Cochrane Neonatal to search the Cochrane Central Register of Controlled Trials (CENTRAL 2018, Issue 5), MEDLINE via PubMed (1966 to 5 June 2018), Embase (1980 to 5 June 2018), and CINAHL (1982 to 5 June 2018). We searched clinical trials databases, conference proceedings, and the reference lists of retrieved articles for randomised controlled trials and quasi-randomised trials.

SELECTION CRITERIA

Randomised or quasi-randomised controlled trials of late initiation of EPO treatment (started at ≥ eight days of age) versus placebo or no intervention in preterm (< 37 weeks) or low birth weight (< 2500 grams) neonates.

DATA COLLECTION AND ANALYSIS

We performed data collection and analyses in accordance with the methods of the Cochrane Neonatal Review Group. We used the GRADE approach to assess the quality of the evidence.

MAIN RESULTS

We include 31 studies (32 comparisons) randomising 1651 preterm infants. Literature searches in 2018 identified one new study for inclusion. No new on-going trials were identified and no studies used darbepoetin.Most included trials were of small sample size. The meta-analysis showed a significant effect on the use of one or more RBC transfusions (21 studies (n = 1202); typical risk ratio (RR) 0.72, 95% confidence interval (CI) 0.65 to 0.79; typical risk difference (RD) -0.17, 95% CI -0.22 to -0.12; typical number needed to treat for an additional beneficial outcome (NNTB) 6, 95% CI 5 to 8). There was moderate heterogeneity for this outcome (RR I² = 66%; RD I² = 58%). The quality of the evidence was very low. We obtained similar results in secondary analyses based on different combinations of high/low doses of EPO and iron supplementation. There was no significant reduction in the total volume (mL/kg) of blood transfused per infant (typical mean difference (MD) -1.6 mL/kg, 95% CI -5.8 to 2.6); 5 studies, 197 infants). There was high heterogeneity for this outcome (I² = 92%). There was a significant reduction in the number of transfusions per infant (11 studies enrolling 817 infants; typical MD -0.22, 95% CI -0.38 to -0.06). There was high heterogeneity for this outcome (I² = 94%).Three studies including 404 infants reported on retinopathy of prematurity (ROP) (all stages or stage not reported), with a typical RR 1.27 (95% CI 0.99 to 1.64) and a typical RD of 0.09 (95% CI -0.00 to 0.18). There was high heterogeneity for this outcome for both RR (I² = 83%) and RD (I² = 82%). The quality of the evidence was very low.Three trials enrolling 442 infants reported on ROP (stage ≥ 3). The typical RR was 1.73 (95% CI 0.92 to 3.24) and the typical RD was 0.05 (95% CI -0.01 to 0.10). There was no heterogeneity for this outcome for RR (I² = 18%) but high heterogeneity for RD (I² = 79%). The quality of the evidence was very low.There were no significant differences in other clinical outcomes including mortality and necrotising enterocolitis. For the outcomes of mortality and necrotising enterocolitis, the quality of the evidence was moderate. Long-term neurodevelopmental outcomes were not reported.

AUTHORS' CONCLUSIONS

Late administration of EPO reduces the use of one or more RBC transfusions, the number of RBC transfusions per infant (< 1 transfusion per infant) but not the total volume (mL/kg) of RBCs transfused per infant. Any donor exposure is likely not avoided as most studies included infants who had received RBC transfusions prior to trial entry. Late EPO does not significantly reduce or increase any clinically important adverse outcomes except for a trend in increased risk for ROP. Further research of the use of late EPO treatment, to prevent donor exposure, is not indicated. Research efforts should focus on limiting donor exposure during the first few days of life in sick neonates, when RBC requirements are most likely to be required and cannot be prevented by late EPO treatment. The use of satellite packs (dividing one unit of donor blood into many smaller aliquots) may reduce donor exposure.

Late erythropoietin for preventing red blood cell transfusion in preterm and/or low birth weight infants

BACKGROUND

Low plasma levels of erythropoietin (EPO) in preterm infants provide a rationale for the use of EPO to prevent or treat anaemia.

OBJECTIVES

To assess the effectiveness and safety of late initiation of erythropoietin (EPO) between eight and 28 days after birth, in reducing the use of red blood cell (RBC) transfusions in preterm and/or low birth weight infants.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, and CINAHL in July 2013. Additional searches included the Pediatric Academic Societies Annual Meetings from 2000 to 2013 (Abstracts2View™) and clinical trials registries (www.clinicaltrials.gov; www.controlled-trials.com; and who.int/ictrp/en). For this update we moved one study from the early EPO review to this late EPO review.

SELECTION CRITERIA

Randomised or quasi-randomised controlled trials of late initiation of EPO treatment (started at ≥ eight days of age) versus placebo or no intervention in preterm (< 37 weeks) and/or low birth weight (< 2500 g) neonates.

DATA COLLECTION AND ANALYSIS

We performed data collection and analyses in accordance with the methods of the Cochrane Neonatal Review Group.

MAIN RESULTS

We include 30 studies (31 comparisons) randomising 1591 preterm infants. Literature searches in 2013 did not identify any new study for inclusion. For this update we moved one study enrolling 230 infants from the early EPO review to this late EPO review.Most included trials were of small sample size. The meta-analysis showed a significant effect of the use of one or more RBC transfusions (20 studies (n = 1142); typical risk ratio (RR) 0.71, 95% confidence interval (CI) 0.64 to 0.79; typical risk difference (RD) -0.17, 95% CI -0.22 to -0.12; typical number needed to treat for an additional beneficial outcome (NNTB) 6, 95% CI 5 to 8). There was moderate heterogeneity for this outcome (RR I² = 68%; RD I² = 60%). We obtained similar results in secondary analyses based on different combinations of high/low doses of EPO and iron supplementation. There was no significant reduction in the total volume (mL/kg) of blood transfused per infant [typical mean difference (MD) -1.6 mL/kg, 95% CI -5.8 to 2.6); 5 studies, 197 infants]. There was high heterogeneity for this outcome (I² = 92%). There was a significant reduction in the number of transfusions per infant (11 studies enrolling 817 infants; typical MD -0.22, 95% CI -0.38 to -0.06). There was high heterogeneity for this outcome (I² = 94%).Three studies including 404 infants reported on retinopathy of prematurity (ROP) (all stages or stage not reported), with a typical RR 1.27 (95% CI 0.99 to 1.64) and a typical RD of 0.09 (95% CI -0.00 to 0.18). There was high heterogeneity for this outcome for both RR (I² = 83%) and RD (I² = 82%). Three trials enrolling 442 infants reported on ROP (stage ≥ 3). The typical RR was 1.73 (95% CI 0.92 to 3.24) and the typical RD was 0.05 (95% CI -0.01 to 0.10). There was minimal heterogeneity for this outcome for RR (I² = 18%) but high heterogeneity for RD (I² = 79%). There were no significant differences in other clinical outcomes. There was no reduction in necrotizing enterocolitis in spite of a reduction in the use of RBC transfusions. Long-term neurodevelopmental outcomes were not reported.

AUTHORS' CONCLUSIONS

Late administration of EPO reduces the use of one or more RBC transfusions, the number of RBC transfusions per infant (< 1 transfusion per infant) but not the total volume (ml/kg) of RBCs transfused per infant. Any donor exposure is likely not avoided as most studies included infants who had received RBC transfusions prior to trial entry. Late EPO does not significantly reduce or increase any clinically important adverse outcomes except for a trend in increased risk for ROP. Further research of the use of late EPO treatment to prevent donor exposure is not indicated. Research efforts should focus on limiting donor exposure during the first few days of life in sick neonates, when RBC requirements are most likely to be required and cannot be prevented by late EPO treatment. The use of satellite packs (dividing one unit of donor blood into many smaller aliquots) may reduce donor exposure.

Late erythropoietin for preventing red blood cell transfusion in preterm and/or low birth weight infants

BACKGROUND

Low plasma levels of erythropoietin (EPO) in preterm infants provide a rationale for the use of EPO to prevent or treat anaemia.

OBJECTIVES

To assess the effectiveness and safety of late initiation of EPO (initiated at eight days after birth or later) in reducing the use of red blood cell (RBC) transfusions in preterm and/or low birth weight infants.

SEARCH METHODS

For this update MEDLINE, EMBASE, CINAHL, and The Cochrane Library were searched in March 2012. Additional searches included the Pediatric Academic Societies Annual Meetings from 2000 to 2012 (Abstracts2 View(TM)) and clinical trials registries (clinicaltrials.gov; controlled-trials.com; and who.int/ictrp).

SELECTION CRITERIA

Randomised or quasi-randomised controlled trials of late initiation of EPO treatment (started at ≥ eight days of age) versus placebo or no intervention in preterm (< 37 weeks) and/or low birth weight (< 2500 g) neonates.

DATA COLLECTION AND ANALYSIS

Data collection and analyses were performed in accordance with the methods of the Cochrane Neonatal Review Group.

MAIN RESULTS

In this 2012 update one new study for inclusion was identified. Twenty-eight studies enrolling 1361 preterm infants in 21 countries were included. Most trials were of small sample size. The meta-analysis showed a significant effect on the use of one or more RBC transfusions [typical risk ratio (RR); 0.66 (95% confidence interval (CI); 0.59 to 0.74); typical risk difference (RD) -0.21 (95% CI; -0.26 to -0.16); typical number needed to benefit (NNTB) of 5 (95% CI 4 to 6) 19 studies, 912 infants]. There was moderate heterogeneity for this outcome [for RR (P < 0.00001; I(2) = 74.0%); for RD (P = 0.0006; I(2) = 58.9%)]. Similar results were obtained in secondary analyses based on different combinations of high/low doses of EPO and iron supplementation. In this update there was no significant reduction in the total volume (mL/kg) of blood transfused per infant [typical MD -1.61mL/kg (95% CI -5.78 to 2.57); 5 studies, 197 infants] There was high heterogeneity for this outcome (P = 0.00001, I(2) = 92%). There was a significant reduction in the number of transfusions per infant (nine studies enrolling 567 infants); [typical MD -0.78 (-0.97 to -0.59)]. Three studies including 331 patients reported on retinopathy of prematurity (ROP) (all stages), with a typical RR 0.79 (95% CI 0.57 to 1.10) and a typical RD of -0.05 (95% CI -0.13 to 0.02). This outcome was not statistically significantly different between the groups. There was no heterogeneity for this outcome for either RR (P = 0.41; I(2) = 0%) or RD (P = 0.43; I(2) = 0%). Two trials enrolling 212 patients reported on severe ROP (stage 3 or greater). The typical RR was 0.83 (95% CI 0.23 to 2.98) and the typical RD was -0.01 (95% CI -0.06 to 0.05); neither were statistically significant. There was no heterogeneity for this outcome for either RR (P = 0.29; I(2) = 9.3%) or RD (P = 0.36; I(2) = 0%).There were no significant differences in other clinical outcomes. Long-term neurodevelopmental outcomes were not reported.

AUTHORS' CONCLUSIONS

Late administration of EPO reduces the use of one or more RBC transfusions, the number of RBC transfusions per infant but not the total volume of RBCs transfused per infant. Any donor exposure is likely not avoided as most studies included infants who had received RBC transfusions prior to trial entry. Late EPO does not significantly reduce or increase any clinically important adverse outcomes. Further research of the use of late EPO treatment to prevent donor exposure is not indicated. Research efforts should focus on limiting donor exposure during the first few days of life in sick neonates, when RBC requirements are most likely to be required and cannot be prevented by late EPO treatment.

Red blood cell transfusions in newborn infants: Revised guidelines

In general, health care professionals taking care of high risk infants in neonatal intensive care units have become more restrictive in their use of red blood cell transfusion over the past 10 years. The present statement is intended for those caring for high risk newborn infants (preterm to one month of age). The objectives of this statement are to provide guidelines to reduce the incidence of anemia in preterm and term infants, to identify strategies to decrease the need for red blood cell transfusions and to limit donor exposure in this population. Recommendations for red blood cell transfusions are included.

Effects of erythropoietin on erythrocyte deformability in non-transfused preterm infants

AIM

Suppression of erythropoiesis due to low plasma erythropoietin levels is an important factor in the development of anaemia of prematurity. Premature infants may therefore be treated with recombinant human erythropoietin (rhEPO). This prospective, randomised and controlled study was designed to find out whether rhEPO treatment improves erythrocyte deformability in preterm infants.

METHODS

Sixteen infants were treated with rhEPO (250 IU/kg three times weekly) a total of 15 times beginning on day of life 5 whereas fifteen infants served as controls. Haemoglobin concentration, haematocrit, reticulocyte count, ferritin level and erythrocyte deformability were measured on days 5, 14, 28, 42 and 63. Erythrocyte elongation was determined as an indicator of erythrocyte deformability using a shear stress diffractometer (Rheodyn SSD) at shear forces of 0.3 to 60 Pa.

RESULTS

Haemoglobin concentration was significantly higher on days 28 and 42 and reticulocyte percentage on day 28 in the rhEPO group compared to the controls. Serum ferritin was lower in the rhEPO group on day 28. Erythrocyte deformability was significantly increased on days 28 and 42 in the infants receiving rhEPO. We found a strong relationship between erythrocyte elongation and reticulocyte count.

CONCLUSION

RhEPO markedly increases the erythropoiesis in preterm infants in the critical first weeks of life and the anaemia of prematurity is obviously reduced. The erythrocyte deformability improved under rhEPO treatment. Erythrocyte deformability was significantly related to the reticulocyte count indicating that the improvement of erythrocyte deformability was due to the formation of well-deformable young erythrocytes.

Effects of a combined therapy of erythropoietin, iron, folate, and vitamin B12 on the transfusion requirements of extremely low birth weight infants

OBJECTIVES

Erythropoietin is frequently administered to premature infants to stimulate erythropoiesis. The primary goal of erythropoietin therapy is to reduce transfusions, but the efficacy of erythropoietin has not been convincingly demonstrated in this regard. The aim of this trial was to investigate whether combined administration of vitamin B12, folic acid, iron, and erythropoietin could decrease transfusion requirements in extremely low birth weight infants.

PATIENTS AND METHODS

In a randomized, controlled trial, extremely low birth weight infants with a birth weight < or = 800 g and a gestational age < or = 32 weeks were randomly assigned to a group receiving combination treatment or a control arm.

RESULTS

The treatment increased levels of folate in red blood cells, vitamin B12, ferritin, transferrin receptor levels in plasma, and reticulocyte counts. The proportion of infants requiring no transfusions was lower in the treatment group (38%) as compared with controls (5%). The treatment group and the need for mechanical ventilation were independent predictors of the number of transfusions in multiple regression analysis. Cox regression analysis indicated that combined therapy resulted in a 79% risk reduction for any transfusion.

CONCLUSION

Combined treatment with erythropoietin, intravenous iron, folate, and vitamin B12 during the first weeks reduces the need for transfusion in extremely low birth weight infants.

Late erythropoietin for preventing red blood cell transfusion in preterm and/or low birth weight infants

BACKGROUND

Hematocrit falls after birth in preterm infants due to physiological factors and blood letting. Low plasma levels of erythropoietin (EPO) in preterm infants provide a rationale for the use of EPO to prevent or treat anemia.

PRIMARY OBJECTIVE

To assess the effectiveness and safety of late initiation of EPO (initiated at 8 days after birth or later) in reducing the use of red blood cell transfusions in preterm and/or low birth weight infants.

SECONDARY OBJECTIVES

Subgroup analyses of low (< 500 IU/kg/week) and high (> 500 IU/kg/week) doses of EPO and within these subgroups analyses of the use of low (< 5 mg/kg/day) and high (> 5 mg/kg/day) doses of supplemental iron, in reducing the use of red blood cell transfusions in these infants.

SEARCH STRATEGY

MEDLINE, EMBASE, CINAHL, abstracts from scientific meetings published in Pediatric Research and reference lists of identified trials and reviews were searched in November 2005/April 2006 and the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 2, 2006). No language restrictions were applied.

SELECTION CRITERIA

Randomised or quasi-randomized controlled trials of late initiation of EPO treatment (started at eight days of age or later) vs. placebo or no intervention in preterm (< 37 weeks) and/or low birth weight (< 2500 g) neonates. For inclusion the studies needed to provide information on at least one outcome of interest.

DATA COLLECTION AND ANALYSIS

Data were abstracted by the two authors on pre-tested data collection forms. Data were entered by one review author (AO) and checked for accuracy by the other (SA). Data were analysed using RevMan 4.2.8. The statistical methods included relative risk (RR), risk difference (RD), number needed to treat to benefit (NNTB), number needed to treat to harm (NNTH) for dichotomous outcomes and weighted mean difference (WMD) for continuous outcomes reported with their 95% confidence intervals (CI). A fixed effects model was used for meta-analyses. Heterogeneity tests including the I squared (I(2)) statistic were performed to assess the appropriateness of pooling the data.

MAIN RESULTS

Twenty-eight studies enrolling 1302 preterm infants in 21 countries were included. The quality of the trials varied. Most trials were of small sample size. Only one study clearly stated that infants were excluded if they had received red blood cell transfusion prior to study entry (Samanci 1996). A total of 19 studies including 912 infants reported on the primary outcome of "Use of one or more red cell transfusions". The meta-analysis showed a significant effect [typical RR; 0.66 (95% CI; 0.59, 0.74); typical RD -0.21 (95% CI; -0.26, -0.16); typical NNTB of 5 (95% CI 4, 6)]. There was statistically significant heterogeneity [for RR (p < 0.00001), I(2 )= 74.0% and for RD (p = 0.0006), I(2 )=58.9%]. Similar results were obtained in secondary analyses based on different combinations of high/low doses of EPO and iron supplementation. There was a significant reduction in the total volume (ml/kg) of blood transfused per infant (four studies enrolling 177 infants) [typical WMD = -7 ml (95% CI -12, -3)] and in the number of transfusions per infant (nine studies enrolling 567 infants); [typical WMD -0.78 (-0.97, -0.59)]. The effect size was less in a post hoc analyses of high quality studies compared to studies in which the quality was uncertain and in studies that used strict guidelines for red blood cell transfusions vs. studies that did not. There were no significant differences in mortality, retinopathy of prematurity, sepsis, intraventricular haemorrhage, periventricular leukomalacia, necrotizing enterocolitis, bronchopulmonary dysplasia, SIDS, neutropenia, hypertension, or length of hospital stay. Long-term neurodevelopmental outcomes were not reported.

AUTHORS' CONCLUSIONS

Late administration of EPO reduces the use of one or more red blood cell transfusions, the number of red blood cell transfusions per infant and the total volume of red blood cell transfused per infant. The clinical importance of the results for the latter two outcomes is marginal (< 1 transfusion per infant and 7 ml/kg of transfused red blood cells). Any donor exposure is likely not avoided as most studies included infants who had received red cell transfusions prior to trial entry. Late EPO does not significantly reduce or increase any of many important neonatal adverse outcomes including mortality and retinopathy of prematurity. Further research of the use of late EPO treatment to prevent donor exposure is not indicated. Research efforts should focus on limiting donor exposure during the first few days of life in sick neonates, when red blood cell requirements are most likely to be required and cannot be prevented by late EPO treatment.

A randomized, controlled trial of the effects of adding vitamin B12 and folate to erythropoietin for the treatment of anemia of prematurity

BACKGROUND

Premature infants, especially those with birth weights of <1500 g, often suffer from anemia of prematurity and associated problems. Erythropoietin therapy is a safe effective way to prevent and to treat anemia of prematurity. We hypothesized that combined administration of vitamin B12 and folate with erythropoietin and iron would enhance erythropoietin-induced erythropoiesis.

METHODS

In a randomized, controlled trial, 64 premature infants (birth weight: 801-1300 g) receiving erythropoietin and iron supplementation were assigned randomly to receive either vitamin B12 (3 microg/kg per day) and folate (100 microg/kg per day) (treatment group) or a lower dose of folate (60 microg/kg per day) (control group).

RESULTS

During the 4-week observation period, vitamin B12 and folate enhanced erythropoietin-induced erythropoiesis significantly, as indicated by a 10% increase in red blood cell counts, compared with folate alone. Hemoglobin and hematocrit levels remained stable in the treatment group, whereas they decreased in the control group. Vitamin B12 levels in the treatment group increased over baseline and control values, whereas red blood cell folate levels were comparable between the groups. Subsequent analysis showed slight nonsignificant differences in baseline red blood cell count, hemoglobin level, hematocrit level, and mean corpuscular volume values, which must be addressed as a limitation.

CONCLUSIONS

With the limitation of a slight imbalance in baseline data between the study groups, combined therapy with vitamin B12, folate, erythropoietin, and orally and intravenously administered iron seemed more effective in stimulating erythropoiesis among premature infants, compared with erythropoietin, iron, and low-dose folate alone. Additional trials are necessary to confirm these data.

Érythropoïétine chez le nouveau-né : efficacité comparée des voies d’administration sous-cutanée et intraveineuse

OBJECTIVE

Our aim was to compare the effectiveness of a one-month treatment with recombinant human erythropoietine (rHuEpo) according to the administration route.

METHODS

Retrospective study based on the data collection from medical files of 64 preterm infant hospitalized in the "institut de puériculture et de périnatalogie" (Paris) between January 13th, 2002 and April 13th, 2002. The first group (N =33) was treated by subcutaneous rHuEpo 750 IU/kg per week, in three injections by week, for one month. The second group (N =15) was treated by continuous infusion of rHuEpo in total parenteral nutrition 1050 IU/kg per week (30% augmentation to compensate the amount absorbed by the filter). The third group (N =16) received 750 IU/kg per week of rHuEpo in three direct intravenous injections. The effectiveness of rHuEpo was evaluated by the absolute reticulocyte count, the level of hemoglobin and the incidence of blood transfusion (multiple logistic analysis of variant and regression).

RESULTS

The absolute reticulocyte count and hemoglobin level were significantly reduced after one month of treatment by continuous infusion of rHuEpo in total parenteral nutrition and direct intravenous injections compared with a one-month treatment by subcutaneous rHuEpo. Hemoglobine level were at 8.8 and 9.6 g/dl vs 10.3 g/dl (P =0.02) and absolute reticulocyte count at 123,000/mm3 and 190,000/mm3 vs 216,000/mm3 (p =0.001). The number of transfused infants was significantly increased with utilization of continuous (40%) and direct intravenous (75%) compared with those treated by subcutaneous route (21.2%) while the ferritin level and phlebotomy losses were not significantly different in the three groups. The number of blood transfusion was significantly linked to phlebotomy losses and administration route of rHuEpo.

CONCLUSION

Our study tends to demonstrate that rHuEpo administered subcutaneously reduces significantly the number of transfusion in contrary to intravenous routes. Waiting for pilot study and new molecules, we recommend subcutaneous administration of rHuEpo to preterm infants 250 IU/kg three times weekly in the treatment of anemia of prematurity.

Erythropoietin: physiology and pharmacology update

This minireview is an update of a 1997 review on erythropoietin (EPO) in this journal. EPO is a 30,400-dalton glycoprotein that regulates red cell production. In the human, EPO is produced by peritubular cells in the kidneys of the adult and in hepatocytes in the fetus. Small amounts of extra-renal EPO are produced by the liver in adult human subjects. EPO binds to an erythroid progenitor cell surface receptor that includes a p66 chain, and, when activated, the p66 protein becomes dimerized. EPO receptor activation induces a JAK2 tyrosine kinase, which leads to tyrosine phosphorylation of the EPO receptor and several proteins. EPO receptor binding leads to intracellular activation of the Ras/mitogen-activated kinase pathway, which is involved with cell proliferation, phosphatidylinositol 3-kinase, and STATS 1, 3, 5A, and 5B transcriptional factors. EPO acts primarily to rescue erythroid cells from apoptosis (programmed cell death) to increase their survival. EPO acts synergistically with several growth factors (SCF, GM-CSF, 1L-3, and IGF-1) to cause maturation and proliferation of erythroid progenitor cells (primarily colony-forming unit-E). Oxygen-dependent regulation of EPO gene expression is postulated to be controlled by a hypoxia-inducible transcription factor (HIF-1alpha). Hypoxia-inducible EPO production is controlled by a 50-bp hypoxia-inducible enhancer that is approximately 120 bp 3' to the polyadenylation site. Hypoxia signal transduction pathways involve kinases A and C, phospholipase A(2), and transcription factors ATF-1 and CREB-1. A model has been proposed for adenosine activation of EPO production that involves protein kinases A and C and the phospholipase A(2) pathway. Other effects of EPO include a hematocrit-independent, vasoconstriction-dependent hypertension, increased endothelin production, upregulation of tissue renin, change in vascular tissue prostaglandins production, stimulation of angiogenesis, and stimulation of endothelial and vascular smooth muscle cell proliferation. Recombinant human EPO (rHuEPO) is currently being used to treat patients with anemias associated with chronic renal failure, AIDS patients with anemia due to treatment with zidovudine, nonmyeloid malignancies in patients treated with chemotherapeutic agents, perioperative surgical patients, and autologous blood donation. A novel erythropoiesis-stimulating factor (NESP, darbepoetin) has been synthesized and when compared with rHuEPO, NESP has a higher carbohydrate content (52% vs 40%), a longer plasma half-life, the amino acid sequence differs from that of native human EPO at five positions, and has been reported to maintain hemoglobin levels just as effectively in patients with chronic renal failure as rHuEPO at less frequent dosing. The use of rHuEPO and darbepoetin to enhance athletic performance is officially banned by most sports-governing bodies because the excessive erythrocytosis can lead to increased thrombogenicity and can cause deep vein, coronary, and cerebral thromboses.

Iron status and the treatment of the anemia of prematurity

Many unanswered issues regarding rhEPO therapy in prematurity remain, including which premature infants best respond to rhEPO, what the long-term effect of decreased erythrocyte transfusions is, how nutritional supplementation optimizes the effect of rhEPO, whether or not rhEpo therapy causes iron deficiency later in life, and whether or not it is safe to supplement with parenteral iron. Further study of rhEPO therapy and iron status in prematurity is necessary.

Nutrient requirements for preterm infant formulas

Achieving appropriate growth and nutrient accretion of preterm and low birth weight (LBW) infants is often difficult during hospitalization because of metabolic and gastrointestinal immaturity and other complicating medical conditions. Advances in the care of preterm-LBW infants, including improved nutrition, have reduced mortality rates for these infants from 9.6 to 6.2% from 1983 to 1997. The Food and Drug Administration (FDA) has responsibility for ensuring the safety and nutritional quality of infant formulas based on current scientific knowledge. Consequently, under FDA contract, an ad hoc Expert Panel was convened by the Life Sciences Research Office of the American Society for Nutritional Sciences to make recommendations for the nutrient content of formulas for preterm-LBW infants based on current scientific knowledge and expert opinion. Recommendations were developed from different criteria than that used for recommendations for term infant formula. To ensure nutrient adequacy, the Panel considered intrauterine accretion rate, organ development, factorial estimates of requirements, nutrient interactions and supplemental feeding studies. Consideration was also given to long-term developmental outcome. Some recommendations were based on current use in domestic preterm formula. Included were recommendations for nutrients not required in formula for term infants such as lactose and arginine. Recommendations, examples, and sample calculations were based on a 1000 g preterm infant consuming 120 kcal/kg and 150 mL/d of an 810 kcal/L formula. A summary of recommendations for energy and 45 nutrient components of enteral formulas for preterm-LBW infants are presented. Recommendations for five nutrient:nutrient ratios are also presented. In addition, critical areas for future research on the nutritional requirements specific for preterm-LBW infants are identified.

Neonatal iron nutrition

Preterm infants are prone to iron deficiency. Their total body iron content at birth is low and gets further depleted by clinical practices such as uncompensated phlebotomy losses and exogenous erythropoietin administration during the neonatal period. Early iron deficiency appears to adversely affect cognitive development in human infants. To maintain iron sufficiency and meet the iron demands of catch-up postnatal growth, iron supplementation is prudent in preterm infants. A dose of 2-4 mg/kg/day is recommended for preterm infants who are fed exclusively human milk. A dose of 6 mg/kg/day or more is needed with the use of exogenous erythropoietin or to correct preexisting iron deficiency. However, due to the poor antioxidant capabilities of preterm infants and the potential role of iron in several oxidant-related perinatal disorders, indiscriminate iron supplementation should be avoided.

The role of high-dose oral iron supplementation during erythropoietin therapy for anemia of prematurity

OBJECTIVE

To assess whether a high intake of oral iron would increase the effect of recombinant human erythropoietin (rHuEPO) on hemoglobin synthesis.

METHODS

We studied 30 preterm infants (gestational age 29+/-1.8 weeks, birth weight 1161+/-200 g, at age of 28+/-10 days) who were randomly assigned to receive either 8 mg/kg per day (n=15) or 16 mg/kg per day of oral iron during a course of rHuEPO therapy (900 microg/kg per week) for a duration of 4 weeks. Both groups were comparable in regard to clinical and laboratory data at the time of enrollment.

RESULTS

rHuEPO caused a significant increase in reticulocyte count in the low- and high-dose iron groups, 17.1+/-5.3 to 34.7+/-9.2 and 16.3+/-3.3 to 42.5+/-5.6 (10(9)/l), respectively (p<0.05). However, in both groups, hematocrit values remained stable at the end of the study as compared to baseline (0.35+/-0.03% vs. 0.30+/-0.03%, 0.35+/-0.05% vs. 0.30+/-0.03%, NS) and in both groups there was a comparable and significant decrease in ferritin level (259+/-109 to 101+/-40 and 168+/-54 to 69+/-38 microg/l, respectively; p<0.01). The rates of bloody stools without any evidence of necrotizing enterocolitis were not significantly different between the two treatment groups (1/15 vs. 4/15, NS).

CONCLUSION

We conclude that a higher dose (16 mg/kg per day) of oral iron is not more beneficial when compared to a lower dose (8 mg/kg per day) during rHuEPO therapy for anemia of prematurity. Further studies will define the optimal dosage and route of administration of iron supplementation during rHuEPO therapy.

Meta-analysis of controlled clinical trials studying the efficacy of rHuEPO in reducing blood transfusions in the anemia of prematurity

BACKGROUND

Recombinant human EPO (rHuEPO) has not gained broad acceptance in the treatment of the anemia of prematurity, because its efficacy in diminishing RBC transfusions is questionable. Meta-analysis was used to investigate the extent and reasons for variation in the results of published clinical trials.

STUDY DESIGN AND METHODS

Prospective controlled trials published from 1990 through 1999 were retrieved; 21 met the criteria for meta-analysis. Calculated across these studies were the summary OR of RBC transfusion in treated neonates as compared with controls and the summary mean difference between controls and treated neonates in the volume of RBCs transfused and the number of RBC transfusions per infant. Twelve study descriptors were examined as possible reasons for the variation in results.

RESULTS

Results of 21 eligible studies varied widely (p<0.001 for the Q test statistic), and this variation persisted in most analyses when studies were stratified by individual study descriptors. When the difference in volume of RBCs transfused was the outcome measure, variation was modest across the four studies with highly desired characteristics (i.e., high blindness and design quality scores, "conservative" transfusion criteria, and the majority of neonates weighing <1 kg at birth), and treatment with rHuEPO reduced RBC transfusions by an average of 11.0 mL per kg (p<0.001).

CONCLUSION

Benefit from rHuEPO is detected across high-quality studies using conservative RBC transfusion criteria. However, there is extreme variation overall in the findings of available trials, and-until this variation is accounted for-it is premature to recommend rHuEPO as standard treatment for the anemia of prematurity.

[Recombinant human erythropoietin in premature infants. Evaluation of a one year experience]

Recently, recombinant human erythropoietin (rhEPO) has been claimed to diminish red blood cell transfusions in premature infants. After a year of experience, we investigated whether early rhEPO treatment would reduce the need for transfusion.

PATIENTS AND METHODS

Fifty premature infants of gestational age < or = 32 weeks admitted to our NICU in 1997, received rhEPO 750 UI/kg/week from day 3 to 5 for six weeks. They were compared with 50 untreated controls admitted in 1996.

RESULTS

The treatment and control groups did not differ for gestational age, weight at birth, CRIB score, and blood losses. We were not able to detect any difference in the number of transfused infants, and in the number of transfusions per infant until discharge. However, treated infants received significantly fewer transfusions per infant between day 16 and day 45 (0.42 +/- 0.67 vs. 0.8 +/- 0.99). Infants with a birth weight between 1,000-1,250 g received fewer transfusions in the EPO group.

CONCLUSION

rhEPO treatment can be useful, but in association with other procedures: conservative transfusion criteria, minimization of phlebotomy losses and early iron supplementation.

High-versus low-dose erythropoietin in extremely low birth weight infants. The European Multicenter rhEPO Study Group

OBJECTIVE

To investigate whether a weekly 1500 IU/kg dose of recombinant human erythropoietin (rhEPO) is more effective than a dose of 750 IU/kg/week in preventing anemia and reducing the transfusion need in infants with birth weights less than 1000 gm.

STUDY DESIGN

In a randomized, double-blind, multicenter trial, 184 infants with birth weights between 500 and 999 gm were treated with either rhEPO 750 (low-dose group) or 1500 IU/kg/week (high-dose group) from day 3 of life until 37 weeks' corrected age.

RESULTS

Thirty-two percent of the infants in each group did not receive any transfusion during the treatment period. The total volume of erythrocytes received was similar in each group. The success rate, defined as no transfusion needed and hematocrit value 0.30 L/L or greater, was 27.6% in the low-dose and 29.5% in the high-dose group (p = 0.96).

CONCLUSION

Doubling the rhEPO dose of 750 IU/kg/week is not indicated in infants with birth weights less than 1000 gm.

The role of erythropoietin in the anemia of prematurity

Neonatal erythropoiesis is limited by a relatively inadequate production of erythropoietin. This is likely the result of dependence on the hepatic production of erythropoietin and an incomplete switchover to renal production. The present model of neonatal erythropoiesis suggests that the use of exogenous erythropoietin should correct the early anemia of prematurity that is observed at 6 weeks of age in premature newborns. Randomized, controlled trials of erythropoietin use in very low birthweight infants are reviewed. The data support the conclusion that erythropoietin at doses of > or = 750 u/kg/wk started at less than 7 days of age results in improved reticulocyte counts and hemoglobin levels, but does not reduce the number of infants who will be exposed to blood products. Erythropoietin at doses of > or = 600 u/kg/wk started at an average of 21 days of life improves reticulocyte counts and hemoglobin levels, and reduces the number of infants will will require late transfusion, but does nothing for the bulk of infants who are transfused before that age.