The evidence of maternal microchimerism in biliary atresia using fluorescent in situ hybridization

胆道闭锁是一种病因不明的胆汁淤积性疾病。最近有研究表明，微嵌合体引起的移植物抗宿主病是自身免疫性疾病发生发展的一种病因。此外，肝脏是移植物抗宿主病常见的靶器官。本研究的目的是确定母体微嵌合体的存在和程度，并确定它是否在BA的病因学中起作用。应用荧光原位杂交(FISH)技术对6例男性BA患者(BA组)和6例男性其他肝病患者(非BA组)的肝活检标本进行X、Y染色体检测。对细胞核内含有两条性染色体的细胞进行计数。具有一条X染色体和一条Y染色体的细胞被认为是宿主细胞，具有两条X染色体的细胞被认为是母源细胞。BA组和非BA组每千个宿主细胞中XX染色体的频率分别为3.00±0.75和0.99±0.50。(P=0.005)。男性BA患者肝脏中女性细胞的出现率明显高于男性其他肝病患者。因此，母体微嵌合体可能与BA的发病有关。

Biliary atresia (BA) is a cholestatic disease of unknown etiology. It has recently been suggested that GVHD caused by microchimerism is an etiology in the development of autoimmune disease. Moreover, the liver is a frequent target organ of GVHD. The aim of this study is to identify the presence and extent of maternal microchimerism and to determine whether it play a role in the etiology of BA. The liver biopsy specimens of 6 male BA patients (BA group) and 6 males with other liver diseases (non-BA group) were assayed for X- and Y-chromosome using fluorescent in situ hybridization (FISH). The cells with two sex chromosomes in the nuclei were counted. Cells with one X- and one Y-chromosomes were considered to be host cells and those with two X-chromosome were considered to be of maternal origin. The frequency of cells with XX chromosomes per 1,000 host cells in the BA group and the non-BA group were 3.00±0.75 and 0.99±0.50, respectively. (P=0.005). The presence of female cells in the liver of male BA patients was significantly higher than in males with other liver disease. Maternal microchimerism is therefore suggested to contribute to the pathogenesis of BA.