Hepatic Erythropoiesis in Infants of Diabetic Mothers: A Morphometric Study

Hepatic erythropoietic tissue is inversely proportional to the gestational age both in infants of diabetic mothers and in control cases. Hepatic erythropoietic and indices range from 17.8 in fetuses and babies before 28 week's gestational age to about 1.0 in fetuses and babies at 40-42 week's gestational age. The decline with gestational age is gradual in the last 10-12 weeks of in utero development. Infants of diabetic mothers who are normally grown have normal amounts of erythropoiesis in their livers. At term, large infants of diabetic mothers have excessive hepatic erythropoiesis. Hypoxia, a frequent feature in infants of diabetic mothers, is probably responsible for the increased erythropoiesis, but an alternate mechanism may be that hyperinsulinemia directly stimulates erythroid precursors or erythropoietin production.     

Hepatic erythropoiesis in infants of diabetic mothers: a morphometric study

Hepatic erythropoietic tissue is inversely proportional to the gestational age both in infants of diabetic mothers and in control cases. Hepatic erythropoietic and indices range from 17.8 in fetuses and babies before 28 weeks' gestational age to about 1.0 in fetuses and babies at 40-42 weeks' gestational age. The decline with gestational age is gradual in the last 10-12 weeks of in utero development. Infants of diabetic mothers who are normally grown have normal amounts of erythropoiesis in their livers. At term, large infants of diabetic mothers have excessive hepatic erythropoiesis. Hypoxia, a frequent feature in infants of diabetic mothers, is probably responsible for the increased erythropoiesis, but an alternate mechanism may be that hyperinsulinemia directly stimulates erythroid precursors or erythropoietin production.     

USE OF RECOMBINANT ERYTHROPOIETIN FOR THE MANAGEMENT OF SEVERE HEMOLYTIC DISEASE OF THE NEWBORN OF A K0 PHENOTYPE MOTHER

Very few people do not express any Kell antigens on their red blood cells (K0 phenotype). They can be immunized by transfusion or pregnancy and develop antibodies against Kell system antigens. These maternal antibodies can cause severe hemolytic disease of the fetus/newborn, as a result of the suppression of erythropoiesis and hemolysis. Multiple intrauterine transfusions in the management of severe hemolytic disease have been shown to cause erythropoietic suppression as well. Recombinant erythropoietin has been successfully used in the management of late anemia of infants with Rh hemolytic disease and in 1 case of KEL1 (Kell)-associated hemolytic disease. The authors present the case of severe hemolytic disease of a newborn due to KEL5 (Ku) isoimmunization of his K0 phenotype mother. Regular intrauterine transfusions were performed to manage the severe fetal anemia (Hb 3 g/dL). A male infant was born at the 36th week of gestation having normal hemoglobin (15.8 g/dL) and developed only mild hyperbilirubinemia. On the 15th day of life, the infant's hematocrit had fallen to 27.3%, with low reticulocyte count and low erythropoietin level. The infant was managed successfully with recombinant erythropoietin.     

Use of recombinant erythropoietin for the management of severe hemolytic disease of the newborn of a K0 phenotype mother

Very few people do not express any Kell antigens on their red blood cells (K0 phenotype). They can be immunized by transfusion or pregnancy and develop antibodies against Kell system antigens. These maternal antibodies can cause severe hemolytic disease of the fetus/newborn, as a result of the suppression of erythropoiesis and hemolysis. Multiple intrauterine transfusions in the management of severe hemolytic disease have been shown to cause erythropoietic suppression as well. Recombinant erythropoietin has been successfully used in the management of late anemia of infants with Rh hemolytic disease and in 1 case of KEL1 (Kell)-associated hemolytic disease. The authors present the case of severe hemolytic disease of a newborn due to KEL5 (Ku) isoimmunization of his K0 phenotype mother. Regular intrauterine transfusions were performed to manage the severe fetal anemia (Hb 3 g/dL). A male infant was born at the 36th week of gestation having normal hemoglobin (15.8 g/dL) and developed only mild hyperbilirubinemia. On the 15th day of life, the infant's hematocrit had fallen to 27.3%, with low reticulocyte count and low erythropoietin level. The infant was managed successfully with recombinant erythropoietin.     

Treatment of refractory aplastic anemia with plasmapheresis: report of a case in childhood with review of the literature

Treatment of aplastic anemia may raise considerable problems in some patients. This report concerns a boy whose illness started at 11 years of age. At first admission laboratory data were: hemoglobin 7.5 g/l, and counts of leucocytes, neutrophils and platelets were 2.3, 0.6, and 8 x 10(9)/l, respectively. His bone marrow was hypoplastic with sparse erythropoiesis. The patient did not respond to traditional medical treatment. Serum contained a high concentration of erythropoietin but no antibodies against erythropoietin. The patient's serum did neither alone, nor supported with recombinant erythropoietin, stimulate erythropoiesis in a bioassay, suggesting that some factor(s) inhibiting erythropoietic activity was present. Based on this hypothesis, plasma exchange was performed. After 26 weeks of plasmapheresis the hematological parameters were normalized. We conclude that plasmapheresis might be an alternative in treatment of resistant aplastic anemia. Further diagnostic tools to identify patients who might benefit from such a treatment are required.     

Age-related differences in erythropoietic response to recombinant human erythropoietin: comparison in adult and infant rhesus monkeys

Human recombinant erythropoietin (r-HuEPO) was given i.v. to rhesus monkeys to compare its safety, erythropoietic effects, and pharmacokinetics in healthy adult and infant animals. Eighteen adult and 18 infant (9- to 15-d-old) monkeys were divided into three groups each of six animals. One group was given 250 U/kg twice weekly, another was given 100 U/kg twice weekly, and a control group was given the drug vehicle for 6 wk. All animals were healthy throughout this period, and for 10 wk after that. Administration of r-HuEPO at these dosages did not produce any changes in leukocytes, platelets, urea nitrogen, bilirubin, creatinine, alkaline phosphatase, alanine amino transferase, gamma-glutamyl transferase, and blood pressure in either age group. At 6 wk, both adult treatment groups had statistically significant increases in Hb concentration. The same dosages that produced these increases in Hb concentration in adults produced no changes in Hb concentration in infant monkeys. Despite active erythropoiesis, as determined by reticulocytosis and increased total body Hb, Hb concentration decreased similarly in the infant treatment and control groups. Pharmacokinetic profiles were obtained at 5 wk of dosing. One h after administration, both doses of r-HuEPO produced significantly lower serum r-HuEPO concentration in the infant monkeys compared with the adults. These differences appeared to be due to a larger volume of distribution of r-HuEPO in the infant monkeys. The t1/2 of r-HuEPO in circulation was the same in both age groups.     

THE EFFECT OF VARIOUS THERAPEUTIC TRIALS ON THE PORPHYRIN EXCRETION IN A CASE OF CONGENITAL ERYTHROPOIETIC PORPHYRIA

ABSTRACT: Eriksen, L. and Seip, M. (Institute of Physiology, University of Oslo, and Department of Pediatrics, University Hospital, Oslo, Norway). The effect of various therapeutic trials on the porphyrin excretion in a case of congenital erythropoietic porphyria. Acta Paediatr Scand 64:287, 1975.–A patient with a biochemically "new" type of congenital erythropoietic porphyria has been studied under various therapeutic trials. Splenectomy had no demonstrable effect on porphyrin excretion or clinical picture. Vitamin E caused a moderate fall in porphyrin excretion, however, there was no significant improvement in light tolerance and tendency to hemolysis. β-carotene reduced skin photosensitivity appreciably, while total porphyrin excretion remained unchanged and the tendency to develop hemolytic anemia showed only slight improvement. Red cell transfusion caused a rapid, dramatic fall in porphyrin excretion (in 4–5 days) and a transient increase in light tolerance, while the distribution of the different porphyrins excreted remained unchanged. These observations indicate that all or nearly all the abnormal porphyrins excreted are of erythropoietic origin, and that the overwhelming part of the porphyrins originate from an abnormal population of shortlived red cells. Findings on fluorescence microscopy of blood and bone marrow support this view. Meticulous protection against light of the shorter wavelengths caused a similar rise in hemoglobin level as produced by red cell transfusion, however, in this instance the total excretion of porphyrins did not fall. It is suggested that the inhibitory effect of transfusion on erythropoiesis (and thereby porphyrin excretion) might be due partly to a depression of erythropoietin formation, partly to the presence of an erythropoiesis inhibiting factor (chalone) in the transfused red cells.     

In vitro studies of bone marrow stem-cell function in uraemic children

Anaemia is a frequent symptom in children with chronic uraemia. There is only limited information about committed haemopoietic stem-cell function in renal insufficiency. The ability of bone-marrow cells to form erythropoietic and granulopoietic cell colonies in vitro was therefore tested in 13 children with chronic renal insufficiency.Following separation of mononuclear cells from bone-marrow aspirates by Ficoll-Isopaque gradient centrifugation, erythropoietic precursor cells were stimulated in plasma clots by erythropoietin. Granulopoietic precursor cells were stimulated in soft-agar gel using feeder layers of normal human leukocytes. The colonies were identified by staining and counted.The number and proliferative capacity of erythropoietic precursor cells (CFU-E) did not seem to be significantly suppressed. Under in vitro conditions, the responsiveness of CFU-E to erythropoietin seemed to be normal.Addition of autologous serum resulted in different degrees of inhibition of erythroid colony formation. The inhibitory effect of the sera was also obvious when uraemic sera were added to bone-marrow cells from subjects without renal disease. Preliminary data indicate that haemodialysis is effective in reducing this inhibitory activity which may be an important factor in the pathogenesis of anaemia in chronic renal insufficiency. The numbers and proliferative capacity of granulopoietic precursor cells (CFU-C) were normal in all the children tested.     

PLASMA ERYTHROPOIETIN CONCENTRATIONS DURING THE EARLY ANEMIA OF PREMATURITY

ABSTRACT. Plasma erythropoietin concentrations were studied in 11 preterm appropriate for gestational age infants at the age of 3-14 weeks. Their birth weights ranged from 860-1690 g. Erythropoietin was measured by a cell culture technique. Significant concentrations of erythropoietin was detected in 18 out of 29 samples, at all stages of the early anemia. The highest levels were found at 3-9 weeks. Individual erythropoietin values did not correlate with hemoglobin concentrations, hematocrit levels or 'corrected' reticulocyte counts, nor did the 'corrected' reticulocyte count correlate with hemoglobin or hematocrit. The lack of correlation with hemoglobin concentration most likely reflects the importance of other factors as well as the hemoglobin in determining the oxygenation status of the infant. A significant positive correlation ( r =0.60, p <0.01) was found between erythropoietin concentration and weight gain in the preceding week. The study shows that small preterm infants are capable of erythropoietin production during their early anemia, and indicates that the hormone plays a role in the regulation of erythropoiesis also at this time of life.     

ERYTHROPOIETIN IN PREMATURE INFANTS

ABSTRACT. The regulation of erythropoiesis during the first three months of life was studied in 30 premature infants who had haemoglobin concentrations which were lower than in term infants of the same postdelivery age. Erythropoietin and erythropoiesis inhibitors were measured by means of an exhypoxic polycythaemic mouse bioassay. The percentage of haemoglobin F was determined as well. An increased erythropoietin level was detected only in six infants older than six weeks, whose blood haemoglobin concentration was lower than 100 g/l, while in serum from other babies erythropoietin was undetectable by the method used. Erythropoiesis inhibitors were present in 80% of the samples tested. The results presented indicate that in premature infants erythropoiesis is regulated through erythropoietin and that inhibitors of erythropoiesis take part in this regulation as well, but that the haemoglobin level at which erythropoietin is increased is lower in preterm infants than in term babies.     

Erythropoietin in premature infants

The regulation of erythropoiesis during the first three months of life was studied in 30 premature infants who had haemoglobin concentrations which were lower than in term in fants of the same postdelivery age. Erythropoietin and erythropoiesis inhibitors were measured by means of an exhypoxic polycythaemic mouse bioassay. The percentage of haemoglobin F was determined as well. An increased erythropoietin level was detected only in six infants older than six weeks, whose blood haemoglobin concentration was lower than 100 g/l, while in serum from other babies erythropoietin was undetectable by the method used. Erythropoiesis inhibitors were present in 80% of the samples tested. The results presented indicate that in premature infants erythropoiesis is regulated through erythropoietin and that inhibitors of erythropoiesis take part in this regulation as well, but that the haemoglobin level at which erythropoietin is increased is lower in preterm infants than in term babies.     

In-vitro studies on the kinetics of bone-marrow erythropoesis during the first trimester of life (Trimenonreduction)]

This study tries to give further insight into the mechanism and location of the physiological reduction of the bone marrow erythropoiesis during the first trimester (Trimenonreduction). Methods utilized included red blood values, bone marrow morphology, 3H-Thymidine Autoradiography, Feulgen-cytophotometry and 3H-, 14C-Thymidine double labelling techniques of bone marrow erythroblasts of healthy children of different age groups. Besides already known techniques we used especially a modification of the double labelling techniques, developed in our laboratories. We draw the following conclusions from our results: 1. Newborns have a higher rate of bone marrow erythropoiesis in comparison with normal controls of other ages. The reduction of the bone marrow erythropoiesis starts already in the first 2 days of life. 2. The reduction of the bone marrow erythropoiesis in the investigated infants in the second week of life was about to one fifth of values which proved to be normal for healthy older children. 3. This reduction is caused partially by prolongation of proliferation and maturation phases of erythroblasts, partially by a decrease of new erythroblast-formation from the stem cell pool. Medium values of DNA-synthesistime of infants with the highest reduction is double compared with values of healthy controls in vitro. 4. The decrease of cell proliferation and maturation during the reduction of the bone-marrow erythropoiesis includes all precursors and all phases of the cell cycle equally. In the first few days of life however it seems that the decrease of DNA synthesizing erythroblasts surpasses the reduction of maturing cells. 5. An ineffectiveness of erythropoiesis could not be found responsible for the reduction. 6. The reduction in erythropoiesis is seen in those steps in which other autors found stimulations by erythropoietin. Therefore this study supports the thesis, that the trimenonreduction is caused by a lack of erythropoietin stimulation. 7. The sequence of the trimenon reduction in humans is different from results found in animals.     

URINARY EXCRETION OF ERYTHROPOIETIN AND ERYTHROPOIESIS INHIBITORS IN THE NEONATAL PERIOD

ABSTRACT. Lindemann, R. (Pediatric Research Institute, Department of Pediatrics, University Hospital, Rikshospitalet, Oslo, Norway). Urinary excretion of erythropoietin and erythropoiesis inhibitors in the neonatal period. Acta Paediatr Scand, 63:764, 1974. —The regulation and suppression of erythropoiesis in the neonatal period has been studied. Urines from normal newborn babies were collected from time of delivery and during the first week of life. Both erythropoietin (ESF) and an erythropoiesis inhibiting factor (EIF) were separated by Sephadex gel filtration. The factors were tested according to days after birth and related to the creatinine coefficient. The exhypoxic polycythemic mouse bioassay was used and the results were expressed as the per cent incorporation of ⁵⁹Fe into newly formed red blood cells. A demonstrable amount of ESF was found only in the urine voided the first day of life, indicating that the ESF production is shut off immediately after birth. From the third day of Life, a marked inhibitory effect of the EIF fractions was found. This may indicate a dual mechanism behind the decrease in neonatal erythropoiesis: a shut off of the ESF production and the appearence of erythropoiesis inhibitors.     

Enterally dosed recombinant human erythropoietin does not stimulate erythropoiesis in neonates

OBJECTIVES: Human fetuses and neonates ingest erythropoietin (Epo) when they swallow amniotic fluid, colostrum, and human milk. This study was designed to determine whether enterally dosed recombinant Epo (rEpo) stimulates erythropoiesis in preterm neonates. METHODS: Preterm infants (<1500 g birth weight) were randomly assigned to receive feedings supplemented with either rEpo (1000 U/kg per day) or placebo for 14 days (n=36). Reticulocyte counts, serum Epo concentrations, hematocrit, and zinc protoporphyrin to heme ratios were measured at baseline and after 7 and 14 days of study drug administration. Transfusion guidelines were followed. Transfusion requirements, medications, feeding tolerance, and clinical diagnoses were documented. RESULTS: Enteral rEpo was well tolerated. There were no differences in erythropoietic indexes based on treatment group. Serum Epo concentrations were not different in the treatment versus placebo group, nor were transfusion requirements. CONCLUSIONS: Enterally dosed rEpo (1000 U/kg/day) does not significantly influence erythropoiesis or iron utilization when given for a 2-week period, nor does it elevate the serum Epo concentration in preterm or term infants. Oral administration of rEpo is not an effective substitute for parenteral administration.     

Primary Benign Erythrocytosis with High Erythropoietin Levels and an Early Erythropoietin-Sensitive Population in the Peripheral Blood

Primary erythrocytosis diagnosed in a 10-month-old female and followed for 12 years is described. The erythrocytosis was associated with an abnormally elevated set point of erythropoietin production in which the sensitivity fluctuated independently, but corresponded to the alterations in the oxygen-carrying capacity of the blood, when the hematocrit was lowered by phlebotomies.

Extensive work for secondary erythrocytes failed to demonstrate a recognizable cause for this abnormal erythropoietin production.

Erythroid cell cultures from peripheral blood mononuclear cells showed the existence of at least two populations: one consistent with dramatic expansion of the erythron in keeping with enhanced sensitivity to endogenous erythropoietin, and the other consistent with the features of typical colonies derived from burst-forming units-erythroid (BFU-Es), seen in normal peripheral blood on days 12 to 14 of culture. The expanded population was characterized by the appearance of single colonies on days 4 to 6 and enormous response to the increasing amounts of erythropoietin, which enhanced their number, size, and maturation. The combination of clinical and in vitro data as well as the absence of any abnormality in the erythropoiesis of the parents and sibling suggest that the erythrocytosis in this child represents a new form with a benign course.     

Effect of recombinant human erythropoietin on transfusion needs in preterm infants

OBJECTIVE: To study the efficacy, safety and cost effectiveness of recombinant human erythropoietin (r-HuEPO) in reducing erythrocyte transfusion needs in very low birthweight (VLBW) infants. METHODS: We conducted a non-blind randomized controlled trial and assigned 100 VLBW infants, less than 33 weeks gestation, to receive either r-HuEPO 750 U/kg per week subcutaneously from day 5 to day 40 or no erythropoietin (EPO). Infants received oral iron 3-6 mg/kg per day from day 10. Transfusion needs were analysed for all enrolled infants and in five weight subgroups: birthweight of less than 600 g, 600-799 g, 800-999 g, 1000-1199 g and infants more than 1200 g. RESULTS: VLBW infants on r-HuEPO attained higher reticulocyte counts and haematocrit than control infants but the mean number of transfusions and volume of erythrocyte transfused per infant were not statistically different. Of infants 800-999 g at birth, the mean number of transfusions per infant was 2.1 compared with 3.5 transfusions per control infant (P = 0.04). Volume of erythrocytes transfused was 34.9 +/- 32.1 mL/kg in r-HuEPO-treated infants and 56.6 +/- 25.8 mL/kg in control infants (P = 0.03). The cost per patient for transfusion and EPO was S$388 for r-HuEPO recipient and S$438 for control infant. Blood pressure, neutrophil count, platelet count and complications of prematurity were not significantly different in both groups of VLBW infants. CONCLUSION: r-HuEPO at 750 U/kg per week stimulates erythropoiesis in VLBW infants but significantly reduces the need for erythrocyte transfusion only in infants weighing 800-999 g at birth.     

Recombinant erythropoietin compared with erythrocyte transfusion in the treatment of anemia of prematurity

To assess the risks and benefits of erythropoietin versus erythrocyte transfusion in the treatment of the anemia of prematurity, we randomly assigned 19 anemic preterm infants (birth weight 988 +/- 227 gm; gestational age 27.6 +/- 1.2 weeks; age 41 +/- 15 days; all values mean +/- SD) to receive either transfusion or subcutaneously administered erythropoietin (200 units/kg every other day for 10 doses). In the 10 erythropoietin recipients, corrected reticulocyte counts increased from 2% +/- 1% to 7% +/- 2% (p less than 0.001) and hematocrits increased from 27% +/- 2% to 30% +/- 4% (p less than 0.05). In the nine infants who underwent transfusion, reticulocyte counts did not increase, but hematocrits increased from 28% +/- 4% to 41% +/- 2% after initial transfusion (p less than 0.001) and had decreased to 34% +/- 5% by day 20. Signs attributed to anemia (tachycardia, apnea with bradycardia, and poor weight gain) declined in both the erythropoietin recipients and those who underwent transfusion. However, five of nine infants who underwent transfusion had symptoms within 10 to 14 days and were given further transfusions. Marrow aspiration performed after 7 to 10 days of treatment showed that infants receiving erythropoietin had greater percentages of erythropoietic precursors (p less than 0.01), greater concentrations of mature erythroid progenitors (p less than 0.001), and higher cycling rates of erythroid progenitors (p less than 0.001). The percentage of mature stored neutrophils in marrow was lower in the erythropoietin group than in the transfusion group, resulting in an inverse myeloid/erythroid ratio (0.5:1 vs 6.2:1; p less than 0.001). After 20 days, absolute blood neutrophil counts were lower in the erythropoietin recipients (1.8 +/- 0.9 x 10(3) cells/microliters) than in the infants who underwent transfusion (3.9 +/- 1.9 x 10(3) cells/microliters; p less than 0.05). Administration of erythropoietin thus stimulated erythropoiesis and relieved signs attributed to anemia; the significance of the relative neutropenia remains to be determined. We conclude that erythropoietin administration offers promise as an alternative to erythrocyte transfusion in neonates with symptomatic anemia of prematurity.     

Severe anemia due to transient pure red cell aplasia in early childhood

Five patients, 11 months to 34/12 years old with severe normochromic, normocytis anemia and reticulocytopenia are reported. At the height of erythropoietic arrest when erythroid precursor cells were completely absent, undifferentiated stem cells (transitional cells), accumulated in the bone marrow. They disappeared again upon spontaneous resumption of erythropoiesis. We suggest that the erythropoietic arrest had occurred at the level of the hematopoietic stem cell.All patients recovered within 1 week of diagnosis. No steroid therapy was given. Failure to recognize this clinical entity leads to unnecessary diagnostic and therapeutic procedures including the transfusion of blood.Supported by the Deutsche Forschungsgemeinschaft, Bonn-Bad Godesberg.     

Relative rates of fetal hemoglobin and adult hemoglobin synthesis in cord blood of infants of insulin-dependent diabetic mothers

Erythrocytosis, extramedullary erythropoiesis, and increased levels of plasma erythropoietin have been observed in newborn infants of diabetic mothers. Because there is evidence that there is a relationship between increased fetal hemoglobin production and acute erythropoietic expansion, it was considered important to study the proportion of fetal hemoglobin and adult hemoglobin synthesis in newborn infants of insulin-dependent diabetic mothers. Samples from nine newborn infants of diabetic mothers as well as nine control infants, ranging from 36 to 38 weeks of gestation, were incubated in an amino acid mixture containing [14C]leucine. The adult hemoglobin and fetal hemoglobin were then separated by column chromatography on DEAE [O-(diethylaminoethyl)] Sephadex. To confirm that the fetal hemoglobin obtained after Sephadex chromatography was not contaminated with other hemoglobins, several of the DEAE separations from each group were reconstituted and subjected to polypeptide chain elution using carboxyl-methyl cellulose chromatography. The data demonstrated that the newborn infants of diabetic mothers are synthesizing significantly more fetal hemoglobin than is expected for their period of development (82.2 +/- 3.6 v 72.8 +/- 4.2; P less than .005). It is suggested that the in utero environment of the fetus of the diabetic mother causes an increase in fetal hemoglobin synthesis.