Domrongkitchaiporn S, Jirakranont B, Atamasrikul K, Ungkanont A, Bunyaratvej A
Departments of Medicine and Pathology, Ramathibodi Hospital, Bangkok, Thailand.
Am J Kidney Dis. 1999 Jul;34(1):29-35. doi: 10.1016/s0272-6386(99)70104-6.
Data for iron-status indices in continuous ambulatory peritoneal dialysis patients are limited. The reliability of commonly used indices for the diagnosis of iron-deficiency anemia in peritoneal dialysis patients is still unknown. To study diagnostic values of iron-status indices, including serum ferritin, transferrin saturation, reticulocyte hemoglobin content, and bone marrow-stainable iron, 21 stable anemic peritoneal dialysis patients who have been treated with erythropoietin and oral iron supplementation for more than 3 months were enrolled in this study. The mean age was 51.4 +/- 2.9 years; dialysis duration, 28.7 +/- 5.1 months; initial hemoglobin, 8.4 +/- 0.2 g/dL; erythropoietin dosage, 71 +/- 2 micro/kg/wk; serum albumin, 3.5 +/- 0.1 g/dL; intact parathyroid hormone (PTH), 233 +/- 44 ng/mL; serum ferritin, 643 +/- 135 ng/mL; transferrin saturation, 33.93% +/- 3.9%; and reticulocyte hemoglobin content, 31.6 +/- 4 pg. Bone marrow aspiration was performed in all patients to determine marrow iron content and exclude hematological disorders. All patients were treated with 1, 000 mg of intravenous ferric saccharate infusion in two divided doses more than 1 week apart. Patients who responded to the iron infusion within 3 months by increasing serum hemoglobin of greater than 1 gm/dL more than baseline were defined as being functional iron deficient before the intravenous iron infusion. Serum ferritin, transferrin saturation, and reticulocyte hemoglobin content were followed serially after iron infusion. Fifteen patients (71.4%) responded to the iron administration, indicating iron deficiency. Nine of 13 (69%) patients with the presence of bone marrow-stainable iron still responded to intravenous iron supplementation, suggesting functional iron deficiency. Absence of bone marrow-stainable iron was not a sensitive marker for the diagnosis of iron deficiency, 25% sensitivity. No single value of iron-status indices that can definitely exclude iron-deficiency anemia in peritoneal dialysis patients was found. Therefore, failure to increase hemoglobin concentration after intravenous iron administration should be shown before excluding iron-deficiency anemia as a cause of poor erythropoietic response to erythropoietin therapy.
持续性非卧床腹膜透析患者铁状态指标的数据有限。腹膜透析患者中常用指标对缺铁性贫血诊断的可靠性仍不清楚。为研究铁状态指标的诊断价值，包括血清铁蛋白、转铁蛋白饱和度、网织红细胞血红蛋白含量和骨髓可染铁，本研究纳入了21例稳定的贫血腹膜透析患者，这些患者接受促红细胞生成素和口服铁剂补充治疗超过3个月。平均年龄为51.4±2.9岁；透析时间为28.7±5.1个月；初始血红蛋白为8.4±0.2 g/dL；促红细胞生成素剂量为71±2微克/千克/周；血清白蛋白为3.5±0.1 g/dL；完整甲状旁腺激素（PTH）为233±44 ng/mL；血清铁蛋白为643±135 ng/mL；转铁蛋白饱和度为33.93%±3.9%；网织红细胞血红蛋白含量为31.6±4 pg。对所有患者进行骨髓穿刺以确定骨髓铁含量并排除血液系统疾病。所有患者均接受1000 mg静脉注射蔗糖铁，分两次给药，间隔超过1周。在静脉注射铁剂前，将在3个月内血清血红蛋白较基线水平升高超过1 gm/dL的铁剂输注反应者定义为功能性缺铁。铁剂输注后连续监测血清铁蛋白、转铁蛋白饱和度和网织红细胞血红蛋白含量。15例患者（71.4%）对铁剂给药有反应，表明存在缺铁。13例骨髓可染铁阳性患者中有9例（69%）对静脉补铁仍有反应，提示功能性缺铁。骨髓可染铁阴性不是缺铁诊断的敏感标志物，敏感性为25%。未发现单一的铁状态指标值能够明确排除腹膜透析患者的缺铁性贫血。因此，在排除缺铁性贫血是促红细胞生成素治疗红细胞生成反应不佳的原因之前，应先证明静脉注射铁剂后血红蛋白浓度未升高。
