Department of Pediatric Hepatology and Gastroenterology, Saiseikai Yokohama Eastern Hospital, Yokohama, Japan.
Hepatol Res. 2015 May;45(5):601-5. doi: 10.1111/hepr.12381. Epub 2014 Jul 29.
Although neonatal hemochromatosis (NH) is a well-known cause of liver failure during the neonatal period and iron deposition in extrahepatic tissues is considered essential in the diagnosis of NH, there is no consensus regarding the pathology or diagnostic criteria of NH. Recent studies of immunohistochemical assays have shown that the C5b-9 complex (the terminal membrane attack complement complex) is strongly expressed in the liver of NH cases, suggesting that a gestational alloimmune mechanism is the cause of liver injury. The patient was a low birthweight primiparous male born at 37 weeks of gestation by vaginal delivery. Blood tests 3 h after birth showed signs of liver failure, including high transferrin saturation, resembling the clinical characteristics of NH. However, magnetic resonance imaging and a lip biopsy showed no obvious iron deposition outside the liver. The patient was refractory to exchange transfusion and immunoglobulin therapy but was successfully treated by liver transplantation. Histologically, the explanted liver showed established cirrhosis, with large amounts of human C5b-9 in the residual hepatocytes, suggesting the alloimmune mechanism of liver injury was the cause of his liver failure. Liver failure caused by a gestational alloimmune mechanism should be considered in patients with antenatal liver failure, even without obvious extrahepatic siderosis.
虽然新生儿血色病（NH）是新生儿期肝衰竭的一个已知原因，并且肝外组织中铁沉积被认为对 NH 的诊断至关重要，但关于 NH 的病理学或诊断标准尚无共识。最近对免疫组织化学检测的研究表明，C5b-9 复合物（末端膜攻击补体复合物）在 NH 病例的肝脏中强烈表达，提示胎源性同种异体免疫机制是导致肝损伤的原因。患者为经阴道分娩的孕 37 周出生的低出生体重初产妇的男性。出生后 3 小时的血液检查显示出肝衰竭的迹象，包括转铁蛋白饱和度高，类似于 NH 的临床特征。然而，磁共振成像和唇部活检显示肝脏外无明显铁沉积。患者对交换输血和免疫球蛋白治疗无反应，但通过肝移植成功治疗。组织学上，移植肝脏显示已建立的肝硬化，残余肝细胞中有大量的人 C5b-9，提示肝损伤的同种异体免疫机制是其肝衰竭的原因。对于产前肝衰竭的患者，即使没有明显的肝外铁沉积，也应考虑胎源性同种异体免疫机制引起的肝衰竭。
