Severe perinatal liver disease and Down syndrome: an apparent relationship

Renal proximal tubular dysgenesis associated with severe neonatal hemosiderotic liver disease

We report the necropsy findings for three infants with the unusual combination of proximal renal tubular dysgenesis and severe congenital liver disease with excessive iron in several organs resembling neonatal hemochromatosis. Two of the infants were caucasian siblings and one was an Australian aborigine. One died in utero at 35 weeks of gestation and two died at 7 days. The liveborn infants presented with anuria and liver failure. The livers all showed marked loss of hepatocytes and replacement by pseudotubules in the collapsed lobules. The liveborn infants also showed giant cell transformation of hepatocytes, small regenerative nodules, cholestasis, and normal bile ducts. Absence of proximal renal convolutions was confirmed by epithelial membrane antigen positivity in nearly all tubules. In each family there was another sibling with congenital liver disease, fatal in one case, but no renal tubular dysgenesis. No infection or metabolic disease was uncovered in any of our patients, and the cause of the hepatocyte destruction was not determined. The combination in three infants of two rare congenital diseases could be genetic or acquired in utero from the same etiological agent. Alternatively, the absence of proximal convolutions could be secondary to hypoperfusion, perhaps because of shock due to extensive necrosis of hepatocytes.

Fetal megakaryocytic dyshemopoiesis in Down syndrome: association with hepatic and pancreatic fibrosis

Trisomy 21 was diagnosed by prenatal blood sampling at 30 and 31 weeks of gestation, respectively, in two fetuses with hepatosplenomegaly. In both, the fetal blood contained blast cells and cells showing megakaryocytic differentiation. Case 1 died neonatally 1 week later and the cellular infiltration causing enlargement of liver and spleen had a megakaryocytic/megakaryoblastic component staining positively for von Willebrand factor and binding to Ulex europaeus 1. Case 2, when stillborn 4 weeks later, had remarkably severe hepatic and pancreatic fibrosis. Cells in pulmonary vessels had morphology and immunohistochemical reactions consistent with megakaryocytic/megakaryoblastic differentiation. Comparison of the two cases suggests that the visceral fibrosis of perinatal Down syndrome may progress very rapidly in utero. They demonstrate further the association of the fibrosis with a dyshemopoiesis in which there is proliferation of cells of megakaryocytic lineage and a close relationship to the transient leukemia of neonatal Down syndrome.

Cytomegalovirus infection, fetal liver disease, and neonatal hemochromatosis

Neonatal hemochromatosis is an uncommon disorder, clinicopathologically defined by severe and generally fatal liver disease of intrauterine onset associated with extrahepatic siderosis that spares reticuloendothelial elements (hemochromatotic siderosis). The agent or agents of liver disease in neonatal hemochromatosis are not known. It also is not known if intrauterine liver disease of defined infective etiology can lead to hemochromatotic siderosis. We present two patients with fetal liver disease and hemochromatotic siderosis whose cases help address these points. In the first patient rare hepatobiliary and numerous renal tubular cytomegalovirus (CMV) inclusions were found; CMV infection was confirmed by the polymerase chain reaction. Studies of the mother of the second patient 1, 5, and 9 weeks post-partum showed recent seroconversion against CMV; seroconversion against other infectious agents (toxoplasma, rubella, herpes, parvovirus B19, hepatitis A/B/C) was not present. Histologic, immunohistochemical, in situ hybridization, or polymerase chain reaction evidence of CMV infection was not present in infant tissues, even though peripartum maternal seroconversion against CMV was observed. We conclude that hemochromatotic siderosis may accompany chronic fetal liver disease of defined infective etiology (patient no. 1) and that recent maternal seroconversion against CMV in the presence of severe fetal liver disease does not necessarily mean that transplacentally acquired CMV infection caused the fetal liver disease (patient no. 2). Polymerase chain reaction documentation of infective-agent genomic sequences in fetal or infant tissues permits more accurate interpretation of maternal serologic data.