Rambod Mehdi, Kovesdy Csaba P, Kalantar-Zadeh Kamyar
Harold Simmons Center for Kidney Disease Research and Epidemiology, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, California, USA.
Clin J Am Soc Nephrol. 2008 Nov;3(6):1691-701. doi: 10.2215/CJN.01070308. Epub 2008 Oct 15.
Serum ferritin, frequently used as a marker of iron status in individuals with chronic kidney disease, is also an inflammatory marker. The concurrent combination of high serum ferritin and low iron saturation ratio (ISAT) usually poses a diagnostic dilemma. We hypothesized that serum ferritin > or =500 ng/ml, especially in the seemingly paradoxical presence of ISAT level <25%, is more strongly associated with inflammation than with iron in maintenance hemodialysis (MHD) patients.
DESIGN, SETTING, AND PARTICIPANTS: In 789 MHD patients in the Los Angeles area, the association of serum ferritin > or =500 ng/ml with inflammatory markers, including IL-6 (IL-6) and C-reactive protein levels, and malnutrition-inflammation score (MIS) was examined.
After multivariate adjustment for case-mix and other measures of malnutrition-inflammation complex, MHD patients with serum ferritin > or =500 ng/ml and ISAT <25% had higher odds ratio for serum C-reactive protein > or =10 mg/L. The area under the receiver operating characteristic curves for the continuum of ISAT and IL-6 in detecting a serum ferritin > or =500 ng/ml were identical (0.57 versus 0.56, P = 0.7). The combination of IL-6 with ISAT yielded a higher area under the receiver operating characteristic curve (0.61) than either ISAT or IL-6 alone (P = 0.03 and P = 0.02, respectively).
In MHD patients, ferritin values above 500 ng/ml, especially in paradoxical conjunction with low ISAT, are associated with inflammation. Strategies to dissociate inflammation from iron metabolism to mitigate the confounding impact of inflammation on iron and to improve iron treatment responsiveness may improve anemia management in chronic kidney disease.
血清铁蛋白常用于慢性肾脏病患者铁状态的标志物，但它也是一种炎症标志物。血清铁蛋白升高与铁饱和度比值（ISAT）降低同时出现时，通常会带来诊断难题。我们推测，血清铁蛋白≥500 ng/ml，尤其是在ISAT水平<25%这种看似矛盾的情况下，与维持性血液透析（MHD）患者的炎症关联更强，而非与铁关联更强。
设计、地点和参与者：在洛杉矶地区的789例MHD患者中，研究血清铁蛋白≥500 ng/ml与包括白细胞介素-6（IL-6）和C反应蛋白水平在内的炎症标志物以及营养不良-炎症评分（MIS）之间的关联。
在对病例组合和营养不良-炎症复合体的其他指标进行多变量调整后，血清铁蛋白≥500 ng/ml且ISAT<25%的MHD患者血清C反应蛋白≥10 mg/L的比值比更高。ISAT和IL-6连续变量检测血清铁蛋白≥500 ng/ml时的受试者操作特征曲线下面积相同（分别为0.57和0.56，P = 0.7）。IL-6与ISAT联合使用时受试者操作特征曲线下面积（0.61）高于单独使用ISAT或IL-6时（分别为P = 0.03和P = 0.02）。
在MHD患者中，铁蛋白值高于500 ng/ml，尤其是与低ISAT值同时出现时，与炎症相关。将炎症与铁代谢分离的策略，以减轻炎症对铁的混杂影响并提高铁治疗反应性，可能会改善慢性肾脏病的贫血管理。
