0810 More evidence of maternal microchimerism in neonatal biliary atresia

Summary 0724 of this series made mention of a small series from Japan that suggested that transplacental passage and chimerism of maternal cells resulted in immune-mediated disease in the neonate, specifically biliary atresia. This research has been picked up by several other investigators, with biliary atresia patients being compared against other subjects with other liver diseases including Alagille’s syndrome, Byler’s syndrome and several cases of neonatal hepatitis. Using a variety of techniques ranging from the presence of XX cells in liver biopsy specimens of male patients with biliary atresia, to specific maternal CD8+ and T cells in their infants’ livers, fluorescent hybridization or PCR analysis, all of the researchers have demonstrated the microchimerism. There is also agreement on the likely pathophysiology i.e. graft vs host disease or some other form/s of immune-mediated attack on the portal area and sinusoids. Most of the research has come from Japan, but Susskind et al of the University of California at San Francisco have also identified the process. Also from the USA is a recent paper looking at risk factors for biliary atresia for the period 1997-2002 and which found that (non-Hispanic) blacks were more predisposed to the condition than whites, that there was a seasonal variation, and that trace elements and vitamins might also be involved (low intakes of vitamin E, copper, phosphorus and iron). If microchimerism is indeed important in the aetiology of this condition then the question remains as to how to link seasonality and micronutrient deficiency to the passage of maternal cells and setting up of an alloimmune or autoimmune reaction.

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Am J Med Genet A 2007; 143: 2274-84
BMC Gastroenterol 2004; 4: 14
Pediatrics 2008; 121: 517-21