Assessment of iron status by erythrocyte ferritin in uremic patients with or without recombinant human erythropoietin therapy.

Erythrocyte ferritin may be a better estimator of iron bioavailability than the conventional markers of iron stores (serum ferritin and transferrin saturation). To investigate the accuracy of these conventional markers in uremic patients compared with erythrocyte ferritin, we studied 29 chronic hemodialysis patients on erythropoietin (EPO) therapy, 18 without EPO therapy, and 22 healthy control subjects. Apart from the red blood cell indices, serum ferritin, transferrin saturation, and erythrocyte ferritin, the analytical study included red blood cell protoporphyrin and plasma aluminum levels. The control group showed erythrocyte ferritin concentrations between 8.3 and 12.5 attograms/cell (95% confidence interval). In the EPO group, red blood cell protoporphyrin correlated negatively with erythrocyte ferritin, but not with serum ferritin or transferrin saturation. In the non-EPO group, serum ferritin, erythrocyte ferritin, and transferrin saturation did not correlate with red blood cell protoporphyrin. Even though erythrocyte ferritin correlated well with serum ferritin in the EPO group (r = 0.61, P = 0.0003), the sensitivity of normal serum ferritin levels (30 to 300 ng/mL) to discard a low erythrocyte ferritin concentration (erythrocyte ferritin less than 7 ag/cell) was 0.53, while the sensitivity of serum ferritin at levels less than 30 ng/mL to indicate an absolute iron deficiency expressed as a low erythrocyte ferritin concentration was 0.28. Only values of serum ferritin and transferrin saturation greater than 300 ng/mL and 35%, respectively, could rule out a relative iron deficiency expressed as a low erythrocyte ferritin and high red blood cell protoporphyrin concentration. Plasma aluminum levels did not correlate with red blood cell protoporphyrin or erythrocyte ferritin levels in either uremic group.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effect of body iron stores on serum aluminum level in hemodialysis patients.

To evaluate the influence of body iron stores on the serum aluminum (Al) level, we studied the correlation between iron status (the serum ferritin, serum iron and transferrin saturation) and serum Al levels in 68 severely anemic hemodialysis patients. Among them, 36 underwent the desferrioxamine (DFO) mobilization test. These 68 patients were divided into three groups according to their serum ferritin level. The basal Al level in the patient group was 41.4 +/- 37.4 micrograms/l (control, 4.1 +/- 2.4 micrograms/l). The serum Al level after DFO infusion of the patient group was 111.1 +/- 86.8 micrograms/l. A significantly higher basal Al and peak Al level after DFO infusion were found in group 1 patients (serum ferritin less than 300 micrograms/l) when compared to group 2 (serum ferritin 300-1,000 micrograms/l) and group 3 (serum ferritin greater than 1,000 micrograms/l) patients. A significant negative correlation between serum ferritin and basal serum Al (r = -0.544, p = 0.0001), as well as peak serum Al after DFO infusion (r = -0.556, p = 0.0001), was noted. Similarly, a negative relationship between serum Al (both basal and peak) and either serum iron or transferrin saturation was noted. However, there was no correlation between the serum Al level and the dosage of aluminum hydroxide. In conclusion, serum ferritin, serum iron and transferrin saturation were inversely correlated with serum Al in our hemodialysis patients. Iron deficiency may probably increase Al accumulation in these patients.     

The prevalence of iron deficiency among patients presenting with colorectal cancer

OBJECTIVES: To examine prospectively the prevalence of iron deficiency among new patients presenting with colorectal cancer and to compare transferrin saturation and serum ferritin as markers of iron deficiency in this group of patients. PATIENTS AND METHODS: Data were gathered on all patients presenting with a new diagnosis of colorectal cancer over a 12-month period. Iron status was estimated and, when possible, confirmed by measurement of serum ferritin concentration and transferrin saturation. Iron status was further examined in relation to tumour site and Dukes' stage. RESULTS: During the study 157 patients presented with a new colorectal cancer. Of these, 130 could be evaluated and 78[60%] had evidence of iron deficiency. Transferrin saturation was below the reference range in 55 patients, but serum ferritin was below in only 18 patients. Among the 49 patients with right-sided cancers, 39[80%] were iron deficient. Iron deficiency was significantly more likely in patients with right sided cancers compared with those with cancers at or distal to the splenic flexure (chi2 = 13, P < 0.001). CONCLUSION: The majority of patients with a new diagnosis of colorectal cancer are iron deficient at presentation. In such patients transferrin saturation measurement is a more sensitive marker of iron deficiency than serum ferritin. The potential role of measuring serum transferrin saturation as an adjunct to faecal occult blood screening should be explored further.     

Serum ferritin levels are increased in patients with glomerular diseases and proteinuria.

BACKGROUND: Ferritin is a high molecular weight protein which reflects body iron stores, but may also rise in the case of an acute phase response. Recently, ferritin has been identified as a predictive factor in the development and progression of atherosclerosis. This is the first report on serum ferritin levels in patients with proteinuria. METHODS: We have analysed the data of 142 male patients with a glomerular disease, and proteinuria exceeding 1 g/day. In all patients, we measured various parameters related to proteinuria, serum ferritin and serum iron. Serum beta2-microglobulin and the Modification of Diet in Renal Disease (MDRD) equation were used as measures of the glomerular filtration rate (GFR). RESULTS: Mean age (+/-SD) was 46+/-15 years, MDRD-GFR 57+/-25 ml/min/1.73 m2 and median proteinuria 8.0 g/day [interquartile range (IQR) 3.6-13]. Serum albumin (29+/-9 g/l) and transferrin levels (1.7+/-0.5 g/l) were low, and cholesterol levels were elevated (median 7.3, IQR 5.9-9.5 mmol/l). Median serum ferritin was 148 microg/l (IQR 89-282), and exceeded 280 microg/l, the upper limit of normal, in 36 patients (25%). Elevated serum ferritin levels could not be explained by an acute phase response as determined by C-reactive protein, or haemochromatosis (DNA analysis). Regression analysis showed an independent relationship between ferritin levels and serum cholesterol, GFR and serum transferrin. CONCLUSIONS: Serum ferritin levels are elevated in patients with overt proteinuria. The independent negative relationship between serum ferritin and transferrin points to a specific process and suggests that increased production of ferritin may compensate for the loss of the iron-binding protein transferrin, thus reducing the amount of free iron. Further studies are needed to elucidate the role of ferritin in patients with proteinuria, especially because of the suggested association between ferritin and atherosclerosis.     

维持性血透患者血清NGAL水平与体内铁存储的相关性研究

目的:探讨在维持性血液透析患者,其血清NGAL(中性粒细胞明胶酶相关载脂蛋白)水平与体内铁存储的关系。方法:从2010年10月开始,我们纳入我院血液透析患者人数150例,同时纳入50例健康人为对照。收集患者及健康对照人群的人口学资料、相关的临床和生化学资料,透析前后NGAL及透析前CRP、转铁蛋白饱和度、铁蛋白、血清铁、转铁蛋白等。做透析前血清NGAL与CRP、转铁蛋白饱和度、铁蛋白、血清铁、转铁蛋白相关性分析。评估NGAL水平在判断体内铁存储的价值。结果:(1)血液透析患者其血清NGAL透析前水平为(445.45±50.34)ng/ml,透析后为(369±50.34)ng/ml,差异有统计学意义(P<0.05)。(2)血液透析患者其血清NGAL水平与CRP、spKt/V、TSAT等指标均有正相关关系(P<0.05),但与铁蛋白、血清铁、转铁蛋白无明显线性关系(P>0.05)。在多元线性回归模型中,NGAL水平与CRP、spKt/V、TSAT有相关关系(P<0.05)。(3)ROC曲线表明,NGAL水平较铁蛋白更好的反映体内铁存储情况,但差异无统计学意义(P>0.05)。结论:在血液透析患者,血清NGAL与spKt/V、CRP、TSAT有不同程度的正相关。血清NGAL能较好的反映体内铁存储情况。     

Hypotransferrinemia of chronically hemodialyzed patients

Increasingly, the iron needs of hemodialysis patients receiving erythropoietin are being met by infusions of intravenous iron guided by laboratory tests to measure body iron availability. The interpretation of assays based on ferritin and transferrin must take into account the effect of inflammation on both proteins and malnutrition on the latter. In our chronic hemodialysis population, hypotransferrinemia was present in greater than 90% of the patients. Using statistical methods and laboratory studies, we sought to identify the principal reasons for the high prevalence of hypotransferrinemia. We observed that transferrin levels were disproportionately low relative to albumin and prealbumin and correlated inversely with ferritin levels. There was no correlation between transferrin and the soluble transferrin receptor. After the infusion of 900 mg of iron, transferrin saturation increased and total transferrin decreased so that unsaturated iron bonding capacity decreased as well. Ferritin concentrations increased significantly after iron loading. Attempts to demonstrate activation of the patients' antioxidant mechanisms associated with iron infusion were negative. We concluded that the low transferrin may be principally the result of diminished synthesis related to the chronic inflammatory status of hemodialysis patients, which favors production of ferritin, but iron and nutritional status may also influence the blood transferrin concentration. These factors make interpretation of transferrin-dependent assessment of body iron stores unreliable and can result in inadequate or overly aggressive iron-replacement therapy.     

Hypoferremia following surgery: a defense mechanism after operative trauma

The purpose of this study is to find the relationship between the serum iron level and defensive function by observing the iron metabolic change following surgical operation, including serum iron, serum ferritin, and urinary iron excretion of TPN patients, and by measuring the NBT test of neutrophilic leukocyte and the level of serum immunoglobulins simultaneously. Thirty surgical patients were studied (10 cholecystectomies, 10 modified radical mastectomies, and 10 subtotal gastrectomies). Following surgical operation, the serum iron level dropped significantly as the result of the stress of operation rather than blood dilatation or urine iron excretion. Both serum ferritin level and the NBT test of neutrophils increased significantly. These results showed that the serum iron may be related to the phagocytic function of neutrophils. Hypoferremia following surgical operation may be a defensive mechanism to prevent postoperative infection.     

Soluble transferrin receptor is correlated with erythropoietin sensitivity in dialysis patients.

BACKGROUND: Iron deficiency is the most common cause of erythropoietin (EPO) resistance in dialyzed patients with renal anemia. Subclinical or functional iron deficiency is difficult to diagnose in these patients. The soluble transferrin receptor (sTf-R) is considered as a sensitive and specific indicator of bone marrow iron availability. PATIENTS AND METHODS: To evaluate the clinical usefulness of this novel marker, we investigated relationships between EPO requirements and various hematological and biochemical parameters of erythropoiesis in 27 pediatric end-stage renal failure patients treated by hemodialysis (HD, n = 11) or chronic peritoneal dialysis (PD, n = 16). Iron was substituted intravenously once or twice per week in HD, and by daily oral administration to PD patients. Serum sTf-R concentrations were measured by an enzyme-linked immunosorbent assay. Serum ferritin and transferrin concentrations were determined using nephelometric assays. Hemoglobin and iron levels were estimated by automated procedures. RESULTS: While neither transferrin saturation nor serum ferritin concentrations were indicative of EPO requirements, a highly significant correlation between the EPO efficacy index (EPO dose divided by hemoglobin concentration) and sTf-R was observed (r = 0.65, p = 0.001). The intravenous iron substitution in HD patients was associated with higher ferritin concentrations compared to the orally substituted PD patients (280+/-100 ng/ml vs. 124+/-83 ng/ml, p<0.002). In contrast, sTf-R concentrations were similar in both treatment groups (25.7+/-7.7 nM vs. 27+/-10.8 nM, n.s.), as were hemoglobin concentrations and EPO requirements. CONCLUSION: Our results suggest that sTf-R is a more sensitive indicator of functional iron deficiency and impaired EPO responsiveness than serum ferritin or transferrin saturation in dialyzed patients. Intensified iron substitution to patients with elevated sTf-R concentrations may considerably improve the cost efficacy of EPO treatment.     

多囊卵巢综合征合并妊娠期糖尿病患者铁代谢与胰岛素抵抗的关系

目的分析多囊卵巢综合征(polycystic ovary syndrome,PCOS)合并妊娠期糖尿病(gestational diabetes mellitus,GDM)患者铁代谢改变及与胰岛素抵抗(insulin resistance,IR)的关系。方法选择2017年1月至2018年2月在烟台毓璜顶医院常规产检,妊娠24~28周的孕妇为筛查对象。确诊为GDM的孕妇60例为GDM组,既往诊断为PCOS且合并GDM的孕妇60例为多囊卵巢合并妊娠期糖尿病(polycystic ovary syndrome with gestational diabetes mellitus,PGDM)组,同时按年龄段进行1∶1∶1匹配,选择正常孕妇60例为正常对照(NC)组。检测3组患者血糖、胰岛素、血红蛋白(Hb)、铁代谢(血清铁、铁蛋白、转铁蛋白饱和度)水平,并评估患者氧化应激损伤及炎症水平的改变,利用多元线性回归法分析铁代谢指标与炎症指标及IR的关系。结果与NC组相比,PGDM组Hb水平降低,铁蛋白(SF)、转铁蛋白饱和度(TS)升高(F=3.55、8.24、5.10,均P<0.05);丙二醛(MDA)水平升高,超氧化物歧化酶(SOD)水平降低(F=11.11、7.24,均P<0.01);肿瘤坏死因子-α(TNF-α)、白介素-6(IL-6)水平升高(F=4.02、19.06,均P<0.05);与GDM组相比,PGDM组Hb水平降低,SF、TS升高,HOMA-IR、MDA、TNF-α、IL-6水平均升高(均P<0.05)。MDA、TNF-α、IL-6与SF呈正相关(r=0.42、0.43、0.56,均P<0.05),与TS呈正相关(r=0.61、0.42、0.52,均P<0.01);SF、TS与胰岛素抵抗指数呈正相关(r=0.39、0.41,均P<0.01)。结论PGDM患者铁沉积状况导致机体氧化应激损伤程度升高,炎症反应增加,从而加重了IR程度。铁代谢紊乱可能与PGDM患者血糖升高机制有关。     

A comparison between the soluble transferrin receptor,transferrin saturation and serum ferritin as markers of iron state in hemodialysis patients

An adequate iron management is important in the treatment of anemia and in hemodialysis (HD) patients. Serum ferritin and transferrin saturation (TS) may be influenced by the presence of inflammation. Recently, the soluble transferrin receptor (s-TfR) has been advocated as a parameter of iron status in HD patients. The aim of the present study was to assess firstly the relation between serum ferritin, TS, and s-TfR in HD patients and to predict their agreement (assessed by kappa) in the diagnosis of iron deficiency, and, secondly, to assess the influence of inflammation on the relation between the parameters of iron state. Iron deficiency by either marker was respectively defined as ferritin <100 microg/l, TS <20%, or s-TfR >2.4 microg/ml. In the overall group of patients, TS and s-TfR were significantly related (r = -0.38), whereas s-TfR and serum ferritin were not. Both serum ferritin and TS were related to CRP (r = 0.50 and -0.34; p < 0.05), whereas s-TfR was not. The kappa value for agreement between serum ferritin and TS in the diagnosis of iron deficiency was 0.24 (p = 0.07), 0.12 (p = NS) for the agreement between TS and s-TfR and 0 for that between serum ferritin and s-TfR. In patients with CRP levels 相似文献   

Safety of intravenous injection of iron saccharate in haemodialysis patients

BACKGROUND.: The most frequent i.v. iron preparations used for haemodialysispatients are iron dextran, iron gluconate and iron saccharate.Possible side effects include anaphylactic reactions due topreformed antibodies to dextran or vascular reactions due tounbound iron during treatment with iron gluconate or iron saccharate. METHODS.: Four dosage regimens of i.v. iron saccharate therapy were studied:10, 20, 40 and 100 mg, which were given over a time period of1 min after the end of the dialysis session. Iron metabolismparameters (serum iron concentration, transferrin saturationand serum ferritin levels) were measured at 0, 1, 5, 15 and30 min after application and immediately prior to the next dialysissession. All 18 regular haemodialysis patients studied receivedrecombinant human erythro-poietin (rHuEpo). RESULTS.: Serum iron levels and transferrin saturation increased significantlyfollowing i.v. injection of all doses of iron saccharate. Iron‘oversaturation’ of transferrin iron binding didnot occur in patients with transferrin levels >180 mg/dl.However, in patients with transferrin levels <180 mg/dl theinjection of 100 mg iron saccharate resulted in a transferrinsaturation of 102.6±39.5% (two patients with transferrinlevels of 87 and 92 mg/dl had transferrin saturations of 119.8and 149.7%, two patients with transferrin levels of 148 and171 mg/dl had transferrin saturations of 77.9 and 63.1%, respectively).Serum ferritin levels remained unchanged during the post-injectionperiod and increased by the next dialysis session followinginjection of 100 mg iron saccharate by 165%. CONCLUSIONS.: It is concluded that intravenous iron saccharate injection (10–100mgeven within 1 min) does not result in ‘oversaturation’of transferrin iron binding if serum transferrin levels are>180mg/dl (high-risk patients: transferrin <100 mg/dl). Thismay explain, at least in part, the minimal side effects observedduring the i.v. application of iron saccharate. Low-dose i.v.iron saccharate (10–40 mg) is recommended for iron supplementationof haemodialysis patients. If injection of 100 mg is necessary,serum transferrin level should exceed 180 mg/dl. There is, however,no need for fast i.v. injection during routine iron supplementation.     

静脉用右旋糖酐氢氧化铁对血液透析患者贫血的疗效

目的采用简明健康测量量表MOS SF-36对维持性血液透析患者在静脉用右旋糖酐氢氧化铁注射液治疗前后生存质量进行评价，以探讨静脉补铁剂对患者贫血和生存质量的干预作用。方法选择慢性肾衰竭行维持性血液透析患者43例，分为静脉用铁剂治疗组（A组）和口服铁剂治疗组（B组），所有患者在纳入研究后采用MOS SF-36量表进行基础评分，在接受静脉补铁治疗10次后再次填写调查表进行评分。结果静脉补铁后患者贫血指标明显改善，与口服补铁患者比较血红蛋白（Hb）升高有统计学差异（P〈0．01），而且静脉补铁患者在生存质量的所有纬度上均较治疗前明显改善，同时与口服补铁患者相比较在生理功能（PF）、总体健康（GH）、活力（VT）、社会功能（SF）、情感职能（RE）、精神健康（MH）等方面具有统计学差异（P〈0．05）。结论静脉补铁剂可有效改善血液液透析患者的贫血状态，提高其患者的生存质量。     

Efficacy of hepatic computed tomography to detect iron overload in chronic hemodialysis

The diagnostic efficacy of hepatic computed tomography density (HCTD) in comparison with serum ferritin for the detection of iron overload was investigated in uremic patients on maintenance hemodialysis (HD) and in patients with idiopathic hemochromatosis (IHC). Ten IHC patients, 38 HD patients and 40 healthy subjects underwent the CT scanning of the liver and determination of percent saturation of transferrin, serum ferritin concentration and HLA typing. Liver iron content was determined by histochemical grading and direct measurement of liver iron concentration either in IHC patients or in HD patients. Nineteen HD patients were considered to have iron overload on the basis of liver iron concentration exceeding 3.6 mumol/100 mg dry weight. The mean +/- SD values of HCTD in healthy subjects, IHC patients, HD patients with iron overload and without iron overload were 60.2 +/- 5.6, 79 +/- 5.6, 71.4 +/- 3.6, 58 +/- 3.8 Hounsfield units, respectively. HCTD showed positive correlations with liver iron concentration and serum ferritin either in IHC patients or in HD patients. The analysis of the diagnostic efficacy of HCTD in comparison with serum ferritin for the detection of excessive hepatic iron in HD patients demonstrated that HCTD had higher sensitivity, specificity, positive and negative predictive values. Cut-off points were arbitrarily fixed to 66 Hounsfield units for HCTD, 400 micrograms/liter for serum ferritin and 3.6 mumol/100 mg dry weight for liver iron concentration. Seventeen HD patients who possessed the histocompatibility antigens associated with IHC, namely HLA-A3 and/or HLA-B7 and/or HLA-B14, had liver iron concentration, serum ferritin and HCTD values higher than those of the HD patients without these "hemochromatosis alleles".(ABSTRACT TRUNCATED AT 250 WORDS)     

Role of prohepcidin, inflammatory markers and iron status in resistance to rhEPO therapy in hemodialysis patients

The aim of our study was to assess possible relations between prohepcidin, iron status and inflammatory markers in hemodialysis (HD) patients, as well as its association with resistance to recombinant human erythropoietin (rhEPO) therapy. Fifty HD patients and 25 healthy controls were enrolled in the study. Among HD patients, 25 were non-responders and 25 were responders to rhEPO therapy. Complete blood cell count, reticulocyte count, and circulating levels of ferritin, iron, transferrin saturation, C-reactive protein (CRP), soluble interleukin (IL)-2 receptor (s-IL2R), soluble transferrin receptor (s-TfR), IL-6 and prohepcidin were measured in all patients and controls. HD patients showed higher circulating levels of ferritin, s-TfR, CRP, IL-6, s-IL2R and prohepcidin, and lower levels of transferrin compared to healthy controls. Higher levels of s-TfR, CRP and lower levels prohepcidin were observed among non-responders compared to responders. Prohepcidin levels correlated negatively with s-TfR and reticulocyte count. The weekly rhEPO/kg dose was found to be positively correlated with CRP, hemoglobin and s-TfR. In conclusion, our data show that a close interaction exists between inflammation, iron status and prohepcidin serum levels that ultimately regulate intracellular iron availability. Prohepcidin and s-TfR, together with CRP, may prove to be good markers of resistance to rhEPO therapy in HD patients.     

A randomized trial of iron deficiency testing strategies in hemodialysis patients.

BACKGROUND: Diagnosis of iron deficiency in hemodialysis patients is limited by the inaccuracy of commonly used tests. Reticulocyte hemoglobin content (CHr) is a test that has shown promise for improved diagnosis in preliminary studies. The purpose of this study was to compare iron management guided by serum ferritin and transferrin saturation to management guided by CHr. METHODS: A total of 157 hemodialysis patients from three centers were randomized to iron management based on (group 1) serum ferritin and transferrin saturation, or (group 2) CHr. Patients were followed for six months. Treatment with intravenous iron dextran, 100 mg for 10 consecutive treatments was initiated if (group 1) serum ferritin <100 ng/mL or transferrin saturation <20%, or (group 2) CHr <29 pg. RESULTS: There was no significant difference between groups in the final mean hematocrit or epoetin dose. The mean weekly dose of iron dextran was 47.7 +/- 35.5 mg in group 1 compared to 22.9 +/- 20.5 mg in group 2 (P = 0.02). The final mean serum ferritin was 399.5 +/- 247.6 ng/mL in group 1 compared to 304.7 +/- 290.6 ng/mL in group 2 (P < 0.05). There was no significant difference in final TSAT or CHr. Coefficient of variation was significantly lower for CHr than serum ferritin and transferrin saturation (3.4% vs. 43.6% and 39.5%, respectively). CONCLUSIONS: CHr is a markedly more stable analyte than serum ferritin or transferrin saturation, and iron management based on CHr results in similar hematocrit and epoetin dosing while significantly reducing IV iron exposure.     

Serum soluble transferrin receptor reflects erythropoiesis but not iron availability in erythropoietin-treated chronic hemodialysis patients

BACKGROUND: The diagnosis of iron deficiency using the current commonly used tests is usually difficult in hemodialysis patients. Soluble transferrin receptor (sTfR) has caught the attention of physicians recently as regards its use as a parameter for the evaluation of iron status. This study was conducted in order to evaluate the correlation of serum soluble transferrin receptor (sTfR) concentration with hematological parameters and iron profiles, in the role of identifying iron deficiency among dialysis patients. METHODS: Seventy-three patients having received chronic hemodialysis and stable maintenance recombinant human erythropoietin (rHuEPO) therapy were included. Iron, total iron-binding capacity, ferritin and sTfR were measured in the first week. Following this, these patients began to receive intravenous iron dextran (2 mg/kg/week) for 4 weeks. The hematocrit (Hct), hemoglobin (Hb) levels and reticulocyte counts were evaluated weekly. At the beginning of fifth week, the sTfR level was measured again. Patients were classified as belonging to one of the following groups: serum ferritin < 100 microg/L - absolute iron-deficient group; initial ferritin level > or = 100 microg/L with an increase in hemoglobin of greater than 1 g/dL at the end of the study occult iron deficiency group; others - non iron-deficient group. RESULTS: Seventy-one patients completed the study. The concentration of sTfR was positively correlated with Hct, Hb and reticulocyte index at the beginning (r = 0.236, p = 0.047; r = 0.257, p = 0.04; r = 0.401, p < 0.01, respectively) and at the end of the study (r = 0.384, p < 0.01; r = 0.338, p < 0.01; r = 0.427, p < 0.001, respectively). After 4 weeks of iron and rHuEPO therapy, the sTfR concentration increased, rather than declined, from 21.85 +/- 8.06 nM to 23.76 +/- 7.42 nM (p = 0.04) and the change was positively correlated with the changes in Hct, Hb and reticulocyte index. The administered rHuEPO doses did not differbetween the iron deficiency group (absolute deficiency, n = 3; occult deficiency, n = 10) and non-iron deficiency group (n = 58). The sTfR levels failed to identify the occult iron deficiency group because there was no difference between occult iron-deficient and non-iron-deficient patients (24.73 +/- 9.09 nM versus 21.60 +/- 7.89 nM, p = 0.34). Instead, transferrin saturation (TS) could be a differential marker between the 2 groups (19.0 +/- 10.9% versus 30.1 +/- 12.7%, p = 0.012). CONCLUSION: The serum sTfR concentration is indeed an appropriate marker for erythropoiesis. The erythropoitic effect of administered rHuEPO could mask the effect of iron status on the sTfR concentration. This might make the sTfR concentration no longer an appropriate index to identify the presence of occult iron deficiency. Thus, TS and ferritin currently remain better methods for the evaluation of iron status in rHuEPO-treated chronic hemodialysis patients.     

Serial ferritin concentrations in hemodialysis patients receiving intravenous iron

BACKGROUND: Treatment of the anemia of chronic renal failure with intravenous iron and erythropoietin is highly effective, but frequently leads to ferritin levels which are much higher than those seen in the general population. High ferritin concentrations raise concern about the potential toxicity of increased body iron stores. PATIENTS AND METHODS: We retrospectively evaluated parameters of iron metabolism over a 4-year period among all our chronic hemodialysis patients who had been receiving intravenous iron and erythropoietin. Initially, patients received intermittent infusions of 300 mg intravenous iron x 3 doses for a low ferritin or low percent saturation of total iron binding capacity (TIBC), but this protocol was subsequently changed to weekly or biweekly infusions of 50-100 mg. RESULTS: We observed an improvement in average hemoglobin values, modest increases in serum iron and saturation of iron binding capacity, and a 125% increase in ferritin levels over 4 years. TIBC decreased. Overall, ferritin values increased 79 microg/l for each 1% increase in TIBC saturation. Ten patients with ferritin concentration greater than 1,000 pg/l received a three month course of vitamin C with no decline in the ferritin concentration. CONCLUSION: Current protocols for iron delivery may result in progressive increases in ferritin levels. Concern about the risks of iron overload should temper the quantity of iron used in dialysis programs.     

Anemia and iron deficiencies among long-term renal transplant recipients

Iron deficiency anemia after renal transplantation has not been systematically investigated. The prevalence of anemia and the indicators of iron deficiency among 438 renal transplant recipients were examined. Anemia was present in 39.7% of the patients. The prevalence of iron deficiencies, as indicated by a percentage of hypochromic red blood cells (HRBC) of >or=2.5%, was 20.1%. The majority of severely anemic patients exhibited HRBC values in the upper quartile. Positive associations of hemoglobin levels with creatinine clearance, serum transferrin levels, male gender, transferrin saturation (TSAT), polycystic kidney disease, and age were observed. Negative associations with erythropoietin therapy, use of azathioprine, serum ferritin levels, and body mass index were observed. The risk for anemia was closely related to the highest quartile of HRBC percentages (odds ratio, 2.35; 95% confidence interval, 1.48 to 3.75; P = 0.00029), whereas ferritin levels and TSAT conferred no risk for anemia. Therefore, assessment of the HRBC proportion is superior to decreased ferritin and decreased TSAT measurements for the diagnosis of iron deficiencies among renal transplant recipients.