慢性肾脏病患者铁过载的MRI定量研究

Quantitative Assessment of Iron Overload in Patients with Chronic Kidney Disease using MRI Technique

目的:通过磁共振HISTO及q-Dixon定量技术对慢性肾脏病患者铁过载情况进行评估,并评价临床常用铁代谢实验室检查对铁过载的预测能力。方法:收集50例慢性脏肾病住院患者行MRI检查,依据患者临床情况分成终末期肾脏病组(ESRD)与非终末期肾脏病组,根据磁共振HISTO定量参数推算的肝脏铁含量(LIC),将患者分为铁过载组与非铁过载组,进行磁共振铁定量参数及实验室检查结果的组间比较。并使用Spearman相关分析研究各参数与肝脏铁含量的相关性,使用logistic回归分析及受试者工作特征(ROC)曲线评估实验室指标的诊断价值。结果:ESRD组的铁过载患病率47.8%,高于非ESRD组的11.1%,肝脏R2值、R2^(*)值高于非ESRD组,差异有统计学意义(P<0.05)。铁过载组的血清铁蛋白(SF)值、脾脏R2^(*)值高于非铁过载组,差异有统计学意义(P<0.05)。Spearman相关分析显示,SF、肝脏R2^(*)、脾脏R2^(*)值与LIC呈正相关(P<0.05),其中SF相关性最好。多重logistic回归分析显示,各临床及实验室指标中仅SF可以区分铁过载与非铁过载,以SF绘制ROC曲线,曲线下面积为0.898。诊断铁过载的SF最佳阈值为349.2μg/L。结论:慢性肾脏病患者中终末期肾脏病患者铁过载患病率较高,多为轻度铁过载,累及肝脏及脾脏,常用的铁代谢指标中仅血清铁蛋白有区分是否存在铁过载的能力。

Purpose:To assess iron overload in patients with chronic kidney disease using MRI HISTO and q-Dixon quantitative protocol,and to evaluate the predictive ability of commonly used laboratory tests in iron overload.Methods:Fifty inpatients with chronic kidney disease who underwent quantitative MRI for iron overload in Huadong Hospital from January 2020 to January 2021 were retrospectively collected.Patients were divided into endstage renal disease(ESRD)group and non-ESRD group according to their clinical conditions and divided into iron overload group and non-iron overload group according to the liver iron concentration(LIC)calculated by the quantitative parameters of HISTO.Spearman correlation analysis was used to study the correlation between each parameter and liver iron concentration.Logistic regression analysis and receiver operating characteristic(ROC)curve were used to evaluate the diagnostic value of laboratory parameters.Results:The prevalence of iron overload in the ESRD group was 47.8%,which was higher than that in the non-ESRD group(11.1%).The liver R2 value and R2^(*)value in the ESRD group were higher than those in the non-ESRD group(43.5 s−1 vs 38.5 s−1,89.6 s−1 vs 48.2 s−1),with a statistically significant difference(P<0.05).The serum ferritin(SF)level(208.5μg/L)and the spleen R2^(*)value(206.4 s−1)in the iron overload group were higher than those in the non-iron overload group(149.0μg/L and 65.6 s−1),and the differences were statistically significant(P<0.05).Spearman correlation analysis showed that SF,liver R2^(*),spleen R2^(*)values were positively correlated with LIC(P<0.05),and SF had the best correlation(r=0.55,95%CI 0.30-0.72;P<0.000 1). Multiple logistic regression analysis showed that only SF among laboratory indicatorscould distinguish iron overload from non-iron overload (OR=1.010, 95%CI 1.004-1.018), and the area under theROC curve was 0.898(95%CI 0.809-0.988). The optimal SF threshold for diagnosing iron overload was 349.2 μg/L.Conclusion: Among patients with CKD, patients with ESRD have a higher prevalence of iron overload, mostly mildiron overload, involving the liver and spleen. Among the commonly used iron metabolism indicators, only SF has theability to distinguish iron overload.