Subcutaneous erythropoietin for treatment of refractory anemia in hematologic disorders. Results of a phase I/II clinical trial.

We have used recombinant human erythropoietin (rHuEPO) in a phase I/II clinical trial to evaluate its ability to reverse refractory anemia in hematologic disorders. rHuEPO was administered subcutaneously 5 days per week at escalating doses (50 to 150 U/kg per day). The aim of treatment was a hemoglobin (Hb) level greater than or equal to 10 g/dL without blood transfusion. Of 25 patients treated, 17 were evaluable, most of them with a regular need for transfusion. Eight of these had lymphoproliferative disorders (three cases of malignant lymphoma and five of monoclonal gammopathy) and were exposed to cytotoxic therapy. The other nine patients had hematopoietic stem cell disorders (four cases of myelodysplastic syndrome, three of idiopathic myelofibrosis, and two of chronic myelogenous leukemia). All patients with lymphoproliferative disorder had serum EPO levels inappropriately low for the degree of anemia, while patients with stem cell disorder showed variable values. Erythroid marrow activity was inadequate in all cases. Seven of eight patients with lymphoproliferative disorder responded to treatment maintaining Hb above 10 g/dL without transfusion. The median dose of rHuEPO required for correction of anemia was 75 U/kg. In four cases response was maintained with 50 U/kg, three times per week. There was no complete response among patients with hematopoietic stem cell disorder, although transfusion requirement was eliminated or reduced in four cases. Four patients developed functional iron deficiency during rHuEPO treatment and required iron supplementation to obtain response. Aggravation of splenomegaly was observed in two cases of myeloproliferative disorder. We conclude that: (1) subcutaneous administration of rHuEPO can be effective and safe in patients with lymphoproliferative disorder exposed to chemotherapy and showing inappropriate EPO response to anemia; (2) this is less likely in hematopoietic stem cell disorders, although favorable responses may be observed in occasional patients; and (3) functional iron deficiency as a cause of nonresponse to rHuEPO is frequent also in nonrenal anemia.     

Diagnostic value of anemia, red blood cell morphology, and reticulocyte count for sickle cell disease.

STUDY OBJECTIVE: To determine the diagnostic value of anemia, RBC morphology, and reticulocyte count for differentiating patients with sickle cell trait from those with sickle cell disease, who have acute medical or surgical conditions and a positive sickle cell screen. DESIGN: Retrospective chart review. SETTING: A midwest urban children's hospital with 220 beds and 36,000 emergency department visits per year. PARTICIPANTS: One hundred six patients with sickle cell trait and 152 patients with sickle cell hemoglobinopathies. RESULTS: Anemia was observed significantly more often in patients with sickle cell disease compared with sickle cell trait (P less than .001) at all ages 3 months and older. However, anemia alone as a diagnostic test lacked high sensitivity and specificity in children less than 4 years old. Sensitivity approached 100% with the presence of anemia, abnormal RBC morphology, or reticulocyte count of more than 2%. CONCLUSION: Absence of anemia alone does not exclude the diagnosis of sickle cell disease in children less than 4 years old. To differentiate trait from sickle cell disease, we recommend determination of not only hemoglobin adjusted for age but also of RBC morphology and reticulocyte count on all children presenting with acute medical and surgical conditions and a positive sickle cell screen.     

Nononcologic use of human recombinant erythropoietin therapy in hospitalized patients

BACKGROUND: Human recombinant erythropoietin (rHuEPO) is widely used to stimulate red blood cell production in patients with anemia due to cancer, renal disease, and other medical conditions, but concern has grown about its overuse and potential for harm. Little is known about the nature of rHuEPO use in hospitalized patients who receive rHuEPO therapy for nononcologic indications. METHODS: We reviewed the drug utilization data from a large academic medical center for all patients admitted during 3 years to identify all patients without cancer who received at least 1 dose of rHuEPO, including their age and sex; diagnoses; hematocrit and hemoglobin and iron levels; and use of supplemental iron. We also compared the rates of laboratory testing and iron supplementation in patients with and without chronic kidney disease (CKD). RESULTS: A total of 1360 distinct patients with 3094 hospitalizations received at least 1 dose of rHuEPO. In 2959 admissions for which hematocrit was determined within 14 days before rHuEPO use, mean values were less than 33% in 1792 (61%) and greater than 36% in 553 (19%). Patients with CKD were more likely than patients without CKD to receive rHuEPO with hematocrit greater than 36% (22% vs 8%; P<.001). Monitoring of iron status was more common in patients with CKD than in those without CKD (64% vs 45%; P <.001). Almost one fourth (23%) of rHuEPO recipients in whom iron levels were measured had absolute iron deficiency (serum ferritin concentration <100 ng/mL). In patients with CKD, only about half (54%) had adequate iron stores at the time of rHuEPO administration; this rate was even lower in patients without CKD (33%; P<.001). Only 66% of patients with documented iron deficiency who were receiving rHuEPO also received concomitant iron supplementation; this rate did not differ between patients with or without CKD. CONCLUSIONS: There is significant variability in the degree of anemia, completeness of iron measurement, and use of iron supplementation in hospitalized patients without cancer who are prescribed rHuEPO. Our results identify potential targets for quality improvement in patients both with and without CKD.     

Acceleration of Iron Utilization After Intravenous Iron Administration During Activated Erythropoiesis in Hemodialysis Patients: A Randomized Study

This study aimed to evaluate the effect of different timings of iron administration during erythropoiesis activated by continuous erythropoietin receptor activator (CERA) on reticulocyte iron uptake in hemodialysis patients. In total, 110 patients were randomized to receive 40 mg intravenous elemental iron doses at all three hemodialysis sessions in the first week (IW1 group: n = 57) or in the third week (IW3 group: n = 53) after CERA administration. Following CERA administration at day 0, reticulocyte count increased, peaking at day 7. At days 7 and 14, the observed changes in Ret‐He were higher in the IW1 group than in the IW3 group. Increases in total reticulocyte hemoglobin at day 7 were higher in the IW1 group than in the IW3 group. In contrast, there was only tendency toward greater total reticulocyte hemoglobin after iron administration in the third week in the IW3 group. Intravenous iron supplementation in the first week of CERA administration increases reticulocyte iron uptake; however, iron supplementation in the third week does not. The findings indicate that iron should be intravenously administered to increase the efficacy of CERA within 1 week of CERA administration during highly active erythropoiesis.     

A multiparameter analysis of sickle erythrocytes in patients undergoing hydroxyurea therapy

During 24 weeks of hydroxyurea treatment, we monitored red blood cell (RBC) parameters in three patients with sickle cell disease, including F-cell and F-reticulocyte profiles, distributions of delay times for intracellular polymerization, sickle erythrocyte adherence to human umbilical vein endothelial cells in a laminar flow chamber, RBC phthalate density profiles, mean corpuscular hemoglobin concentration and cation content, reticulocyte mean corpuscular hemoglobin concentration, 1H-nuclear magnetic resonance transverse relaxation rates of packed RBCs, and plasma membrane lateral and rotational mobilities of band 3 and glycophorins. Hydroxyurea increases the fraction of cells with sufficiently long delay times to escape the microcirculation before polymerization begins. Furthermore, high pretreatment adherence to human umbilical vein endothelial cells of sickle RBCs decreased to normal after only 2 weeks of hydroxyurea treatment, preceding the increase in fetal hemoglobin levels. The lower adhesion of sickle RBCs to endothelium would facilitate escape from the microcirculation before polymerization begins. Hydroxyurea shifted several biochemical and biophysical parameters of sickle erythrocytes toward values observed with hemoglobin SC disease, suggesting that hydroxyurea moderates sickle cell disease toward the milder, but still clinically significant, hemoglobin SC disease. The 50% reduction in sickle crises documented in the Multicenter Study of Hydroxyurea in Sickle Cell Disease is consistent with this degree of erythrocyte improvement.     

Low fixed-dose hydroxyurea in severely affected Indian children with sickle cell disease

There is limited data on the efficacy of hydroxyurea (HU) in Indian sickle cell anemia patients who have severe manifestations despite high fetal hemoglobin (Hb F). Sixty sickle cell anemia children (5-18 years) with more than three episodes of vasoocclusive crises or blood transfusions per year were randomized to receive HU (n = 30) or placebo (n = 30) therapy. Fixed dose (10 mg/kg/day) of HU was administered for 18 months and the patients were followed-up monthly with clinical assessment and laboratory monitoring. In the HU group, hemoglobin (Hb) and Hb F levels increased significantly along with a significant decrease in the number of painful crises, blood transfusion requirements and hospitalizations compared to the placebo group. No major adverse events were observed in this study. In conclusion, low-fixed dose HU therapy was effective for the treatment of Indian sickle cell anemia children. However, there is a need for long-term studies to evaluate the efficacy and toxicity in a larger number of Indian sickle cell anemia patients.     

OBSERVATIONS ON THE EFFECT OF MASSIVE DOSES OF IRON GIVEN INTRAVENOUSLY TO PATIENTS WITH HYPOCHROMIC ANEMIA

Massive doses of iron (from 0.608 to 1.32 Gm. as colloidal terric hydroxide orcolloidal ferric oxide) were given intravenously in single infusions to 8 differentpatients with hypochromic microcytic anemia. One patient was given a secondinjection after an interval of four months, so that nine administrations were made.The following observations were made:

1. The reticulocyte response was higher in each instance than would be expectedin oral therapy. In 3 additional patients in whom injection had to be discontinuedafter 0.070, 0.180, and 0.123 Gm. of elemental iron had respectively been given, thereticulocyte rises were higher than were the average responses reported by Heath¹⁸after optimal oral therapy. This at least suggests that "optimal" oral therapy doesnot provide a maximal stimulus to outpouring of reticulocytes from the bone marrow. Comparable doses of iron given to 3 control subjects with normal hemoglobinlevels did not cause a reticulocytosis.

2. The average rate of hemoglobin regeneration per 100 cc. of blood per day was0.224 Gm.; the lowest value was 0.16 Gm. and the highest 0.27 Gm. These figureswere calculated for the rise that occurred from the day of iron administration to thetime at which the rate of hemoglobin increase was obviously becoming slower.Since correction was not made for blood loss in 3 of the patients during the periodof regeneration, the figures for the rate of hemoglobin formation are lower thanthey otherwise would have been. Even so they are distinctly greater than thoseusually obtained following oral therapy (table 2), but no greater than is found in anoccasional patient given iron by mouth. The data suggest that the fastest rate ofhemoglobin regeneration that can be stimulated by iron in subjects with hypochromic anemia approximates 0.3 Gm. per 100 cc. per day.

3. Calculations indicated that from 71.8 to 99.7 per cent of the injected iron wasapparently used for the synthesis of hemoglobin. These figures are likewise lowerthan they would have been if several of the patients had not lost blood during therecovery period. The observation of other workers that parenterally administerediron is almost completely retained by the body and converted into hemoglobin wastherefore confirmed.

4. Toxic reactions to the injected iron are described in detail. They were severein all but two instances, and in 3 patients were so alarming that injection of ironhad to be discontinued. There can be no doubt that the reactions to iron parenterally administered in large doses are great enough to contra-indicate use of thismeasure as a therapeutic procedure.

     

Evaluation of erythroid marrow response to recombinant human erythropoietin in patients with cancer anaemia.

BACKGROUND. Anaemia is a frequent finding in patients with cancer and may be due to different causes, including blunted erythropoietin production. MATERIALS AND METHODS. In a pilot study, we administered recombinant human erythropoietin (rHuEPO) to twelve patients with solid tumours and secondary anaemia. rHuEPO was given subcutaneously 5 d per week at escalating doses (75 to 150 U/kg per day): the aim of treatment was a Hb level > or = 10 g/dl without blood transfusion. We evaluated endogenous EPO production through serum EPO levels and erythroid marrow activity by means of serum transferrin receptor (TfR). RESULTS. Six out of 12 subjects had defective endogenous EPO production. All patients but two responded to treatment with steady increases in Hb levels above 10 g/dl, and the median dose of rHuEPO required for correction of anaemia was 75 U/kg. Response was associated with an early increase in serum TfR. Six patients developed functional iron deficiency and required iron supplementation to obtain response. Treatment improved functional ability in 4/10 responders. CONCLUSIONS. Subcutaneous rHuEPO can stimulate erythroid marrow activity in cancer anaemia, even in patients with advanced disease, and marrow response can be adequately monitored by serum TfR. Functional iron deficiency as a cause of nonresponse to rHuEPO is frequent in these patients and may require parenteral iron administration. Although erythropoietin can improve the anaemia of cancer, the decision to treat should be individualised for each patient, looking more at the quality of life and cost-effectiveness than at cosmetic increases in the haemoglobin level.     

Correction of copper deficiency improves erythropoietin unresponsiveness in hemodialysis patients with anemia

We have encountered five hemodialysis patients who had received enteral nutrition and recovered from erythropoietin-resistant anemia with neutropenia after the correction of copper deficiency. We reduced the required doses of recombinant human erythropoietin (rHuEPO) to maintain the target hematocrit levels and three patients were finally weaned from the rHuEPO therapy. Thus, copper deficiency is involved in erythropoietin-resistant anemia in hemodialysis patients.     

Leg ulcers in patients with sickle cell disease [see comments]

During the entry examination, leg ulcers were present in 2.5% of 2,075 patients 10 years of age and older with sickle cell disease who entered into the Cooperative Study of Sickle Cell Disease (CSSCD) between 1979 and 1986. Prevalence rates were highest among patients with sickle cell anemia and sickle cell anemia with thalassemia genotypes. Among sickle cell anemia patients free of ulcers at entry, the overall incidence was 5.73 per 100 person years in those having associated alpha-thalassemia and 9.97 for those without. Among sickle cell anemia patients with two alpha genes, the estimated incidence of leg ulcers is 2.38 per 100 person years and 6.12 per 100 person years among sickle cell anemia patients with three alpha genes (P less than .05). In both groups, the incidence was highest among those patients over 20 years of age and considerably higher among males than females (P less than .001). Leg ulcers were nonexistent in patients with sickle beta plus thalassemia and sickle hemoglobin C disease. Low steady-state hemoglobin is associated with a higher incidence of ulcer formation (P less than .0001) in sickle cell anemia patients. The protective effect of hemoglobin F is apparent at all levels of total hemoglobin among sickle cell anemia patients and those with associated alpha-thalassemia.     

Sickle Cell--Hemoglobin C Disease: Quantitative Determination of Iron Kinetics and Hemoglobin Synthesis

Quantitative determinations of iron kinetics and hemoglobin synthesis weremade on five patients with sickle cell-hemoglobin C disease. The anemia wasmild in all patients but one who had the hemoglobin of 10.1 Gm. per cent.All patients were in a steady state during the period of this study.

The ferrokinetic determinations demonstrated a hemolytic process in allcases. The mean erythrocyte life span in these patients was 18, 20, 29, 46and 56 days respectively (normal range, 110-130 days). The hemoglobinsynthesis was increased in all. Reduced to terms of daily hemoglobin production per liter of blood, the values were 2.2 Gm., 2.9 Gm., 3.6 Gm., 5.8 Gm.and 6.6 Gm. The latter figure represents a five fold increase over the normalmean value of daily hemoglobin synthesis of 1.3 Gm. (normal range, 1.0 to1.6 Gm. of hemoglobin per liter of blood per day).

The results of the in vivo organ counts demonstrated a significant degreeof sequestration of red blood cells in the spleen of two patients. The questionof advisability of splenectomy in such patients was discussed.

Accepted on December 3, 1962     

Importance of anemia and transferrin levels in the regulation of intestinal iron absorption in hypotransferrinemic mice.

The hypotransferrinemic mouse (trf (hpx)) is a mutant strain exhibiting transferrin deficiency, marked anemia, hyperabsorption of iron, and elevated hepatic iron stores. We set out to investigate the relative roles of anemia and of transferrin in the malregulation of intestinal iron absorption in these animals. Transfusion of erythrocytes obtained from littermate controls increased hemoglobin levels and reduced reticulocyte counts in recipient animals. Although mucosal to carcass (59)Fe transfer was reduced, total duodenal iron uptake was not significantly affected. Iron absorption in homozygotes, in contrast to littermate controls, was not reduced by hyperoxia. Mouse transferrin injections, in the short term, increased delivery of iron to the marrow and raised hemoglobin levels. Although mucosal transfer and total iron uptake were reduced at the higher transferrin doses, total uptake was still higher than in controls. Daily injections of mouse/human transferrin for 3 weeks from weaning, normalized hemoglobin values, and markedly reduced liver iron and intestinal iron absorption values in trf (hpx) animals. When such daily-injected mice were left for a week to allow transferrin clearance, iron absorption values were significantly enhanced; hemoglobin or hepatic iron levels were, however, not significantly altered. These data indicate that hyperabsorption of iron in trf (hpx) mice is not solely because of the anemia; transferrin levels per se do affect iron absorption, possibly via a direct effect on the intestinal mucosa.     

Treatment of the anemia of chronic renal failure with subcutaneous recombinant human erythropoietin

PURPOSE: The purpose of this study was to determine the efficacy of recombinant human erythropoietin (rHuEPO) given subcutaneously three times/week in patients with chronic renal failure and anemia (predialysis). PATIENTS AND METHODS: Eleven patients with predialysis chronic renal failure participated in a double-blind, placebo-controlled study of subcutaneously administered erythropoietin. For 12 weeks, patients received either rHuEPO 100 mu/kg body weight three times/week subcutananeously or a placebo. After 12 weeks of placebo, patients now also received rHuEPO in a dose up to 150 mu/kg three times/week until target hematocrit was achieved. Throughout the study, blood pressure was monitored closely and blood work was obtained regularly for hemoglobin, hematocrit, reticulocyte count, and iron profile determinations. RESULTS: At 12 weeks, the hematocrit of the treated group had risen from 29% +/- 2% to 35% +/- 2% (p less than 0.001). The placebo group baseline hematocrit was 28% +/- 2% and at 12 weeks 26% +/- 2% After 12 weeks of rHuEPO therapy, the hematocrit of the prior placebo group was 32% +/- 2% (p less than 0.001 versus baseline). No significant change in biochemical parameters was noted. Mean blood pressure values were comparable before and after treatment. All protein ultimately required iron supplementation. In two patients, the rate of progression of renal failure appeared to increase as their hematocrit rose and rHuEPO was discontinued. CONCLUSIONS: It is concluded that rHuEPO given subcutaneously is an effective and safe therapy for patients with chronic renal failure who are anemic and who are not receiving dialysis.     

Erythropoietin Administration May Potentiate Mobilization of Storage Iron in Patients on Oral Iron Chelation Therapy

Five, repeatedly transfused, patients with refractory anemia (RA) or RA with ringed sideroblast (RARS) subtypes of myelodysplastic syndrome (MDS), with serum ferritin (SF) levels of >2,000 μg/L, and one female with Hb E [β26(B8)Glu→Lys]/β⁰-thalassemia (thal) with an SF level of 1,760 μg/L, were treated with deferiprone (L1) at the dose of 4–6 g per day for at least 26 months. Beginning in the second month, all patients received recombinant human erythropoietin (rHuEPO) at the dose of 150 IU/kg thrice weekly, subcutaneously for 24 months. A significant increase in iron excretion after combined administration of L1 and rHuEPO compared to treatment with L1 as a single agent, was observed in all patients. The amount of excreted iron in urine ranged from 7.5 to almost 20 mg per day. In one patient, a response to rHuEPO resulted in transfusion independence and her SF decreased from 2086 to 879 μg/L. In four MDS patients, who remained dependent on red blood cell (RBC) transfusions, simultaneous administration of L1 and rHuEPO enabled the stabilization of SF levels, despite continuing iron load from the transfusions. Combined administration of rHuEPO and oral iron chelators may potentiate mobilization of storage iron and maintain iron balance in transfusion-dependent iron overloaded early MDS patients.     

Erythropoietin administration may potentiate mobilization of storage iron in patients on oral iron chelation therapy

Five, repeatedly transfused, patients with refractory anemia (RA) or RA with ringed sideroblast (RARS) subtypes of myelodysplastic syndrome (MDS), with serum ferritin (SF) levels of > 2,000 microg/L, and one female with Hb E [beta26(B8)Glu --> Lys]/beta0-thalassemia (thal) with an SF level of 1,760 microg/ L, were treated with deferiprone (L1) at the dose of 4-6 g per day for at least 26 months. Beginning in the second month, all patients received recombinant human erythropoietin (rHuEPO) at the dose of 150 IU/kg thrice weekly, subcutaneously for 24 months. A significant increase in iron excretion after combined administration of L1 and rHuEPO compared to treatment with L1 as a single agent, was observed in all patients. The amount of excreted iron in urine ranged from 7.5 to almost 20 mg per day. In one patient, a response to rHuEPO resulted in transfusion independence and her SF decreased from 2086 to 879 microg/L. In four MDS patients, who remained dependent on red blood cell (RBC) transfusions, simultaneous administration of L1 and rHuEPO enabled the stabilization of SF levels, despite continuing iron load from the transfusions. Combined administration of rHuEPO and oral iron chelators may potentiate mobilization of storage iron and maintain iron balance in transfusion-dependent iron overloaded early MDS patients.     

Effects of hydroxyurea on hemoglobin F and water content in the red blood cells of dogs and of patients with sickle cell anemia.

A rationale for clinical trials of hydroxyurea (HU) treatment in sickle cell disease is that the agent increases red blood cell (RBC) fetal hemoglobin content. However, an additional effect of HU is to raise the mean corpuscular volume (MCV). To investigate the action of HU in a species that makes no electrophoretically distinguishable fetal hemoglobin, we treated dogs with the drug and compared their response to that of five patients with sickle cell anemia. Both dogs and patients had an increase in MCV, but the effect of HU treatment on the mean corpuscular hemoglobin concentration (MCHC), density, and water content of the RBCs differed in the two species. The dog RBCs became low in MCHC, high in ion and water content, and low in mean density. Thus, HU can raise MCV and lower MCHC without influencing fetal hemoglobin synthesis. A different pattern was seen in the sickle cell patients during HU treatment. Although the MCV of their RBCs increased, there was no change in MCHC, ion content, or mean density. A notable change in the sickle cell patients' blood was that two subpopulations of cells were nearly eliminated during HU treatment; the hypodense reticulocyte fraction and the hyperdense fraction that contains irreversibly sickled cells. These findings lead us to suggest that trials of HU in sickle cell disease must recognize the possibility that any beneficial effect of this agent might be due not only to an increase in hemoglobin F alone, but perhaps also to the associated increase in MCV or the altered RBC density profile.     

Determinants of red cell survival and erythropoietic activity in patients with sickle cell anemia in the steady state

We have studied 26 patients with sickle cell anemia to determine the factors that affect red blood cell (RBC) survival and other parameters of erythropoietic activity in the steady state. Determinants of erythropoietic activity included RBC survival by the 51Cr method, RBC production/destruction rate, alpha genotype, beta(s) haplotype, plasma 59Fe clearance, plasma iron turnover, erythron transferrin uptake), RBC Fe utilization, reticulocyte count, and erythropoietin levels. The alpha genotype was the most significant determinant of RBC survival followed, to a lesser extent, by the beta(s) haplotype. Hb F showed no correlation with RBC survival due to patient selection bias - the patients studied had comparable Hb F levels to start with. Other determinants of erythropoietic activity (hemoglobin level, mean corpuscular volume, reticulocyte count, RBC mass, RBC production/destruction rate, and erythropoietin level) were most likely secondary determinants associated with the alpha genotype, and not independent determinants in themselves. The data suggest that the alpha genotype and, and to a lesser extent, the beta(s) haplotype, might be determinants of the severity of the anemia of sickle cell disease, and should be considered in genetic counseling and patient selection for aggressive therapeutic interventions.     

Improvement of anemia in hemodialysis patients treated by hemodiafiltration with high-volume on-line-prepared substitution fluid

BACKGROUND: Hemodiafiltration (HDF) is associated with a lower incidence of neuropathy, carpal tunnel syndrome, joint pain, and partial correction of anemia. HDF with on-line-prepared substitution fluid (OL HDF), as compared with conventional hemodialysis, increases the treatment tolerance and, as compared with standard HDF, avoids storage problems and allows a higher substitution volume at low cost. METHODS: Thirty-two hemodialysis patients treated by OL HDF for at least 9 months were studied. Hemoglobin, hematocrit, iron metabolism, serum albumin, dialysis dose and dry body weight were determined under a settled condition with regular hemodialysis 3 months before the transfer to OL HDF. The same parameters were analyzed 3, 6 and 9 months after the beginning of the new treatment modality. RESULTS: During OL HDF, hemoglobin values significantly increased in patients without addition of recombinant human erythropoietin (rHuEPO): baseline vs. 6 months 11 +/- 1.7 vs. 12 +/- 1.8 g/dl (p < 0.01); baseline vs. 9 months 11 +/- 1.7 vs. 12 +/- 1.6 g/dl (p < 0.05). In patients on a maintenance dose of rhuEPO, this could be significantly reduced, while the target hemoglobin levels were maintained (10.6 +/- 0.9 g/dl): baseline 99.8 +/- 50.4 U/kg/week, 3rd month 76.2 +/- 43 U/kg/week, 6th month 64.3 +/- 37 U/kg/week, and 9th month 59.4 +/- 38.6 U/kg/week (p = 0.007, p = 0.0006, and p = 0.0007, respectively, vs. baseline). Iron metabolism, dialysis dose, dry body weight and serum albumin levels did not significantly change during the follow-up period. Further, a stability of the rHuEPO supplementation was observed in 14 patients followed up for 24 months. CONCLUSIONS: OL HDF influences anemia and rHuEPO dose. It allows considerable anemia correction in patients without rHuEPO treatment, while it significantly reduces rHuEPO doses in those on rHuEPO treatment as compared with standard hemodialysis. The rHuEPO costs are consequently reduced.     

Hemorheological risk factors of acute chest syndrome and painful vaso-occlusive crisis in children with sickle cell disease

Background

Little is known about the effects of blood rheology on the occurrence of acute chest syndrome and painful vaso-occlusive crises in children with sickle cell anemia and hemoglobin SC disease.

Design and Methods

To address this issue, steady-state hemorheological profiles (blood viscosity, red blood cell deformability, aggregation properties) and hematologic parameters were assessed in 44 children with sickle cell anemia and 49 children with hemoglobin SC disease (8-16 years old) followed since birth. Clinical charts were retrospectively reviewed to determine prior acute chest syndrome or vaso-occlusive episodes, and rates of these complications were calculated.

Results

Multivariate analysis revealed that: 1) a higher steady-state blood viscosity was associated with a higher rate of vaso-occlusive crises in children with sickle cell anemia, but not in children with hemoglobin SC disease; 2) a higher steady-state red blood cell disaggregation threshold was associated with previous history of acute chest syndrome in children with hemoglobin SC disease and boys with sickle cell anemia.

Conclusions

Our results indicate for the first time that the red blood cell aggregation properties may play a role in the pathophysiology of acute chest syndrome in children with hemoglobin SC disease and boys with sickle cell anemia. In addition, whereas greater blood viscosity is associated with a higher rate of vaso-occlusive crises in children with sickle cell anemia, no association was found in children with hemoglobin SC disease, underscoring differences in the etiology of vaso-occlusive crises between sickle cell anemia and hemoglobin SC disease.Key words: sickle cell anemia, hemoglobin SC disease, red blood aggregation, blood viscosity, red blood cell deformability     

Sickle cell anemia: Erythrokinetics,blood volumes,and a study of possible determinants of severity

The variability in the clinical expression of sickle cell anemia led us to study factors which might influence the course of this disease. We examined erythrokinetics, blood volumes, and variables which influence hemoglobin function in a group of adults with sickle cell anemia of varying degrees of clinical severity. We were unable to correlate any single measurement with the clinical course; however, our patient sample was small and the data suggested areas for further study. An expansion of plasma volume was noted in all patients. This made it difficult to predict red cell mass from the hemoglobin level, which consistently underestimated its magnitude. The red cell production index and iron turnover values indicated that there is often a suboptimal erythropoietic response to anemia in sickle cell disease.