地中海贫血铁代谢特点及器官铁沉积的检测

Iron overload status and assessment of organ iron overload in patients with thalassemia

输血依赖型地中海贫血(重型地贫,TDT)和非输血依赖型地贫(NTDT)患者由于长期反复输血和肠道铁吸收增加导致铁过载,过多的铁沉积于心、肝、胰腺及垂体等组织器官,引起组织细胞损伤和器官功能衰竭,临床表现为心功能衰竭、肝硬化、糖尿病和生长发育障碍等,最终引起死亡。心脏核磁共振(MRI)T2~*和肝脏MRI R2值可以很好地反映心脏和肝脏的铁负荷。在NTDT患者血清铁蛋白(SF)常会低估体内铁过载的程度。检测脏器铁沉积情况及选择合适的螯合剂祛铁治疗是减低地贫患者铁过载并发症的必要手段。

Repeated blood transfusion therapy is the major cause of iron overload in thalassaemia major and increased GI absorption is more important in non-transfusion dependent thalassaemia (NTDT).Iron overload is inevitable because the human body lacks a mechanism to excrete excess iron.Iron accumulation is toxic to many tissues,causing heart failure,cirrhosis,diabetes,growth retardation and multiple endocrine abnormalities.MRI T2* and MRI R2technique is now validated as a true measure of cardiac iron and liver iron concentration respectively.Serum ferritin underestimates liver iron concentration in NTDT Patients.Assessment of iron overload status in NTDT patients should be done through liver iron concentration measurement.