Lokmanya Tilak Municipal Medical College and General Hospital, Sion, Mumbai, India.
Lokmanya Tilak Municipal Medical College and General Hospital, Sion, Mumbai, India.
Clin Gastroenterol Hepatol. 2017 Feb;15(2):292-298.e1. doi: 10.1016/j.cgh.2016.08.046. Epub 2016 Sep 17.
BACKGROUND & AIMS: We investigated whether tissue elastography (TE) can be used as an alternative to magnetic resonance imaging (MRI) T2* analysis to determine the degree of iron overload in patients with thalassemia major.
We conducted a prospective study of 154 patients (99 male; mean age, 12 ± 3.6 years) with thalassemia major requiring chronic blood transfusion and on iron chelator therapy. The study was performed at a tertiary hospital in India from January 2015 through June 2015. We performed routine blood sample analyses, measurements of serum levels of ferritin, and TE within 1 month of MRI T2* analysis of the liver. The Spearman correlation test and linear regression analysis were used to evaluate the correlation between TE liver stiffness measurements and R2* MRI results or serum ferritin levels.
The subjects' mean total serum levels of bilirubin, alanine aminotransferase, aspartate aminotransferase, and albumin were 1.4 ± 0.6 mg/dL, 65.0 ± 51.8 IU/L, 62.9 ± 44 IU/L, and 4.2 ± 0.2 g/d, respectively. Mean liver stiffness measurement, MRI T2* (3 T), corresponding MRI R2* (3 T), and ferritin values were 8.2 ± 4.4 kPa, 3.18 ± 2.6 milliseconds, 617.3 ± 549 Hz, and 4712 ± 3301 ng/mL, respectively. On the basis of MRI analysis, 67 patients (43.5%) had mild iron overload, 49 patients (31.8%) had moderate iron overload, and 22 patients (14.3%) had severe iron overload. Fibroscan liver stiffness measurements correlated with MRI R2* values (r = 0.85; P < .001). TE results identified the patients with severe, moderate, and mild iron overload with area under the receiver operating characteristic curve values of 94.8%, 84.5%, and 84.7%, respectively. Liver stiffness measurements greater than 13.5, 7.8, and 5.5 kPa identified patients with severe, moderate, and mild iron overload, respectively; the sensitivity and specificity values were 92% and 93% for severe overload, 82% and 82% for moderate overload, and 73% and 75% for mild overload. No correlation was found between TE results and serum level of ferritin (r = 0.19; P = .11).
Results of TE correlate with those from MRI T2* analysis. TE is cheaper and more available than MRI and might be used to estimate hepatic iron overload, especially moderate to severe overload in patients with thalassemia major who require chronic transfusion.
我们研究了组织弹性成像（TE）是否可以替代磁共振成像（MRI）T2*分析来确定地中海贫血患者的铁过载程度。
我们在印度的一家三级医院进行了一项前瞻性研究，共纳入 154 名需要长期输血和铁螯合剂治疗的地中海贫血患者（99 名男性；平均年龄 12 ± 3.6 岁）。该研究于 2015 年 1 月至 2015 年 6 月期间进行。我们在进行 MRI T2分析肝脏后 1 个月内进行常规血液样本分析、血清铁蛋白水平测量和 TE。使用 Spearman 相关检验和线性回归分析评估 TE 肝硬度测量值与 R2MRI 结果或血清铁蛋白水平之间的相关性。
研究对象的总胆红素、丙氨酸转氨酶、天冬氨酸转氨酶和白蛋白血清水平分别为 1.4 ± 0.6 mg/dL、65.0 ± 51.8 IU/L、62.9 ± 44 IU/L 和 4.2 ± 0.2 g/dL。平均肝硬度测量值、MRI T2*（3 T）、相应的 MRI R2*（3 T）和铁蛋白值分别为 8.2 ± 4.4 kPa、3.18 ± 2.6 毫秒、617.3 ± 549 Hz 和 4712 ± 3301 ng/mL。根据 MRI 分析，67 名患者（43.5%）存在轻度铁过载，49 名患者（31.8%）存在中度铁过载，22 名患者（14.3%）存在重度铁过载。Fibroscan 肝硬度测量值与 MRI R2*值呈正相关（r=0.85；P<.001）。TE 结果可识别出重度、中度和轻度铁过载患者，受试者工作特征曲线下面积分别为 94.8%、84.5%和 84.7%。肝硬度测量值大于 13.5、7.8 和 5.5 kPa 分别识别出重度、中度和轻度铁过载患者；对于重度过载，其敏感性和特异性值分别为 92%和 93%，对于中度过载分别为 82%和 82%，对于轻度过载分别为 73%和 75%。TE 结果与血清铁蛋白水平无相关性（r=0.19；P=0.11）。
TE 结果与 MRI T2*分析结果相关。TE 比 MRI 更便宜、更普及，可能用于估计地中海贫血患者的肝铁过载，尤其是需要长期输血的患者的中重度肝铁过载。
