Evaluation of the stability of human erythropoietin in samples for radioimmunoassay

Eckardt, Kai‐Uwe; Kurtz, Armin; Hirth, Peter; Scigalla, P.; Wieczorek, Lothar; Bauer, Christian

doi:10.1007/bf01748163

Cited by 91 publications

(57 citation statements)

References 7 publications

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“…We determined the EPO concentration in EDTA-plasma samples by radioimmunoassay as described previously, 15 using a rabbit antiserum derived against recombinant human EPO, iodinated recombinant human EPO (Amersham Laboratories, Amersham, UK) as a tracer and using the 2nd International Reference Preparation for EPO (WHO/International Laboratory for Biological Standards, London, UK) as a standard. The interassay coefficient of variation is 7 percent.…”

Section: Determination Of Erythropoietinmentioning

confidence: 99%

Serial immunoreactive erythropoietin levels in autologous blood donors

Lorentz¹,

Jendrissek²,

Eckardt

et al. 1991

Transfusion

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The variations in plasma erythropoietin (EPO) concentration during preoperative deposit of autologous blood were studied in 12 patients (8 men, 4 women). Four donations were scheduled at weekly intervals. A predonation hemoglobin concentration of 11 g per dL (110 g/L) was required. Hemoglobin concentration decreased from 14.3 ± 1.1 g per dL (143 ± 11 g/L) (mean ± SD) before the first donation to 11.7 ± 0.7 g per dL (117 ± 7 g/L) on Day 22 (p<0.0001). Reticulocyte counts increased from a median of 31,800 (range, 4900-95,000) per \xL (median, 32 x 10 9 /L [range, 5-95 x 10 9 /L]) to 93,800 (16,800-194,900) per \iL (median, 94 x 10 9 /L [range, 17-195 x 10 9 /L]) on Day 28 (p<0.01). Plasma EPO concentration was 17.8 ± 5.1 mU per mL prior to the first donation and displayed a small and transient peak after each donation. A sustained elevation followed each peak. Although plasma EPO concentration differed significantly from the baseline value after the first donation, only the peak concentrations after the second (35.5 ± 15.5 mU/mL), third (38.0 ± 14.5 mU/ mL), and fourth (36.1 ±11.0 mU/mL) donations exceeded the normal range. The moderate, biphasic increase in plasma EPO concentration and the moderate increase in erythropoiesis suggest two strategies in autologous blood donation that should be investigated with respect to efficiency and safety: 1) more aggressive donation schemes, which reduce donation intervals and/or the minimum hemoglobin concentration and 2) the administration of recombinant human EPO. TRANSFUSION 1991;31:650-654. Abbreviations: EPO = erythropoietin.THE IMMUNOLOGIC AND INFECTIOUS risks of transfusion 1,2 can be minimized by the use of autologous blood. Preoperative autologous blood donation considerably reduces homologous transfusion requirements in surgery. 3 " 8 Frozen storage of red cells allows the preoperative deposit of a large number of blood units, but it is costly and time-consuming. On the other hand, liquid storage is limited to 5 weeks for whole blood and 7 weeks for packed red cells. 9,10 The efficiency of preoperative deposit in the liquid state thus depends on the rate of recovery from blood loss, that is, on the degree of stimulation of erythropoiesis.Erythropoietin (EPO) is the primary humoral regulator of erythropoiesis. 11 Increasing the availability of EPO may therefore enhance the efficiency of preoperative donation programs. This increased availability of EPO may be achieved by allowing the modulation of donation schemes (shorter donation intervals, lower minimum

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Section: Determination Of Erythropoietinmentioning

confidence: 99%

Serial immunoreactive erythropoietin levels in autologous blood donors

Lorentz¹,

Jendrissek²,

Eckardt

et al. 1991

Transfusion

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“…SiEPO was determined by radioimmunoassay exactly as described [6]. In brief, 100 gl samples plus 20 gl of 30% bovine serum albumin were incubated with 100 gl rabbit antiserum raised against recombinant human EPO for 24h.…”

Section: Radioirnmunoassay For Epomentioning

confidence: 99%

Serum immunoreactive erythropoietin of children in health and disease

et al. 1990

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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).

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“…In the main study we gave the same dose of rHuEPO SC to the rest of the patients, rHuEPO was supplied as a sterile buffered solution (1 ampoule = 4,000 units/ml, Cilag, Sulzbach, Germany). For the determination of serum EPO concentrations, blood samples were taken from an indwelling venous catheter immediately before and 10, 20, 30 and 60 min and2, 3,4,5,8,12,16,18,20,24,30,36,48 and 72 h (hi some children 96 h) after rHuEPO application. The centrifuged serum samples were stored at -20~ until analysis.…”

Section: Methodsmentioning

confidence: 99%

“…In haemodialysed patients the drug was administered immediately after termination of the session and blood was analysed only during dialysis-free intervals. The radioimmunoassay used for EPO estimation had been described previously [20]. 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.…”

Section: Methodsmentioning

confidence: 99%

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

et al. 1993

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Abstract. The single-dose pharmacokinetics of recombinant human erythropoietin (rHuEPO) given SC was investigated in 20 patients aged 7-20 years at different stages of chronic renal failure. In a pilot study we confirmed the lower bioavailability of the drug in 2 children when given SC compared with the IV route (24% and 43%, respectively). Following administration of 4,000 units/m2, rHuEPO SC effective serum erythropoietin concentrations increased from a mean baseline level (_+ SD) of 23 ___ 13 units/1 to a mean peak concentration of 265 _+ 123 units/l, which was reached after 14.3 ___ 9.4 h, followed by a slow decline until baseline values were attained at 72 h. Mean residence time was 30 +9 h and mean elimination halftime 14.3 +7 h. The single-dose kinetics of SC rHuEPO in children with different degrees of renal failure are comparable to those in adult patients. Possibly, the higher efficacy of SC rHuEPO in patients with renal anaemia compared with IV rHuEPO is related to its prolonged action.

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Evaluation of the stability of human erythropoietin in samples for radioimmunoassay

Cited by 91 publications

References 7 publications

Serial immunoreactive erythropoietin levels in autologous blood donors

Serial immunoreactive erythropoietin levels in autologous blood donors

Serum immunoreactive erythropoietin of children in health and disease

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

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