Low Does Intravenous Ascorbic Acid for Erythropoietin-Hyporesponsive Anemia in Hemodialysis Patients with Iron Overload

以低劑量維他命C治療血液透析病人之貧血

張弘育(Hung-Yu Chang) ； 莊峰榮(Feng-Rong Chuang) ； 郭慧亮(Huey-Liang Kuo) ； 王怡寬(I-Kuan Wang) ； 林俊良(Chun-Liang Lin) ； 黃秋錦(Chiu-Ching Huang)

《Acta Nephrologica》 16卷3期 (2002/07) Pp. 108-113

摘要

最近的研究証實，鐵過量的血液透析病人由於對鐵的利用不良，反而會造成對紅血球生成素（EPO）的反應不佳。靜脈注射維他命C被証實可嘲是有效的輔助療法。然而低劑量維他命C是否也有其功效，則未被証實。我們設計這個研究來分析是否低劑量維他命C也能對這群病人有助益。42長期血液透析病人速內研究的第一期，每週接受兩次2,000單位紅血球生成素共12週。在最後四週血比容未達30%者被視為EPO反應不良者。共有16位反應不良者進入研究的第二期，並接受100毫克維他命C，一週三次共8週。在第一期研究中，21個反應良好和16個反應不良者，其基本條件並沒有差異，但是反應良好者有較低的血清鐵蛋白值以及較高的運鐵蛋飽和度。在第二期研究中，平均血比容在第八週時比上第0週時有意義地增加（29.5±2.2比上27.7±1.7% P值＜0.05），運鐵蛋白飽和度也由原先的27.0±7.8%，在第八週時有意義地上升至31.9±4.9%（P＜0.05），而鐵蛋白由原先的823.5±171.4，在第八週時有意義地下降至650.7±165.1（P＜0.05）。本研究証實低劑量維他命C可以增加鐵的釋放以及利用，並可以是EPO有效的輔助劑。

關鍵字

貧血 ； 維他命C ； 血液透析 ； 鐵貯存過量 ； 紅血球生成素反應不良

並列摘要

Background: Recent studies have demonstrated that inadequate iron mobilization and defective rion utilization may cause recombinant erythropoieitin (rhEPO) hyporesponsiveness in hemodialysis (HD) patients with iron overload. Intravenous ascorbic acid (IVAA) has also been proven effective in HD patients selected based on iron overload and rhEPO resistance. However, the efficacy of lower dose IVAA in HD patients with hyperferritinemia is uncertain. This study focuses on such patients to analyze the effect of low dose IVAA in improving anemia and erythropoiesis.
Materials and Methods: Forty-two chronic stable HD patients were enrooled in the study. In phase I, patients were treated with rhEPO 2000 U twice weekly for 12 weeks. Patients whose hematocrit values failed to reach the target level (above 30%) int the last four weeks werer defined as poor responders. Sixteen poor responders then were enrolled in the phase Ⅱ strudy and received low dose IVAA (100 mg thrice weekly) for 8 weeks.
Results: The demographic characteristics of the 21 good responders and 16 poor responders showed no differences in age, sex H/D duration, serum albumin, serum aluminum, serum iPTH and KT/V. This study in the phase Ⅰ period demonstrated that the good responders of rhEPO therapy tend to have lower ferritin levels and higher TSAT levels compared to the poor responders. As for phase Ⅱ, mean HCT level was significantly increased at the 8(superscript th) week (27.7±1.7 vs 19.5±2/2%, P＜0.05). TSAT also was raised at the 4(superscript th) and 8(superscript th) weeks compared to the start of phase Ⅱ (32.3±5.2, 31.9±4.9 vs 27.0±7.8, P＜0.05). Finally, mean ferritin was significantly lower at the 8th week of phase Ⅱ compared to its initial value (650.7±165.1 vs 823.4±171.5, P＜0.05).
Conclusion: Low dose IVAA therapy provides and acceptable adjuvant therapy for facilitating iron release from the reticuloendothelial system and also increases iron utilization in HD patients with iron overload.

並列關鍵字

Anemia ； intravenous ascorbic acid ； hemodialysis (HD) ； iron overload ； erythropoietin hyporesponsiveness