Serum immunoreactive erythropoietin of children in health and disease

Abstract

Abstract. Serum immunoreactive erythropoietin (siEPO) was determined in cord serum from neonates (n = 97, gestational age 36-43 weeks), in healthy children from birth to adolescence (n = 260) and in children with haematological (n = 30), renal (n = 10) and congenital heart diseases (n = 70). In healthy children siEPO levels decreased after birth (geometric mean cord siEPO 35.6mU/ml with 95% range of 17-56mU/ml in eutrophic, nondistressed fetuses) and reached lowest values during the first 2 months (geometric mean siEPO ll.5mU/ ml). Thereafter siEPO levels increased slightly and were constant between 2 months and adolescence. The geometric mean siEPO for healthy children after birth was 18.8mU/ml with 95% range of 7-47 mU/ml. These estimates were not significantly different from normal adult values. In newborns with fetal distress (n = 15) cord siEPO was significantly elevated (geometric mean 63.0 mU/ml; P < 0.001). In children with haematological disease, siEPO and Hb concentration were inversely correlated (log siEPO (mU/ml)= 4.1 -0.20 x Hb (g/dl); r=-0.62; P<0.0005). This relationship was significantly different in children with chronic renal failure (log siEPO (mU/ml) = 0.67 + 0.035 • Hb (g/dl); r = 0.50; P = 0.1). In children with heart disease the geometric mean siEPO was 19.2mU/ml with 95% range 8-65 mU/ml for cyanotic (SaO2 < 94%) and 17.7 mU/ml with 95% range of 12-36 mU/ml for acyanotic patients. In this group siEPO values were inversely correlated to the arterial oxygen content (log siEPO (mU/ml) = 1.61 -2.04 x oxygen content (1/t); r = -0.28; P < 0.02).

Unexplained Elevated Serum hCG Is Associated with Raised Amniotic Fluid Erythropoietin Levels in Second-Trimester Pregnancies

“…High erythrocyte and erythropoietin levels are also found in the umbilical cord blood of chronically hypoxemic fetuses [9,15]. Erythropoietin as the main regulator of erythropoiesis in fetal life appears to be controlled by the state of oxygenation, at least in animal studies.…”

“…Whatever the mechanism, early placental damage is reflected by elevated maternal serum hCG levels in the second trimester. On the other hand, in abnormal pregnancies a number of situations are associated with fetal oxygen deprivation and, accordingly, with raised fetal erythropoietin values [9][10][11]. Amniotic fluid erythropoietin concentrations are known to run parallel to those in fetal blood [11,12].…”

Increased plasma viscosity as a reason for inappropriate erythropoietin formation.

“…ma)/(patient -hctnomal) as a standardized parameter which we termed "EPO response." Normal EPO concentration of healthy adults (mean hematocrit 45%) average 17 mU/ml when measured with the radioimmunoassay used for this study ( 10). For nonrenal anemias average values for the EPO response are in the range of6 to 10 (8-10).…”

Pharmacokinetics of recombinant human erythropoietin applied subcutaneously to children with chronic renal failure

“…It has a lower detection limit of 5 units/l with an interassay coefficient of variation (CV) of 6.7% for an EPO concentration of 44 units/l. In normal children below 15 years of age, serum EPO levels determined by the same assay range between 7 and 47 units/1 (mean 18.8 units/t); in adolescents up to the age of 20 years they are between 13 and 36 units/1 (mean 21 units/l) [21].…”