Abstract 107

The primary site of TPO gene expression in adults is the liver and to a lesser extent the kidney. We investigated of TPO gene expression in human fetuses and neonates. In 12 fetuses delivered after pregnancy termination due to severe malformations or congenital disorders and in 14 preterm infants with early postnatal death we measured platelet counts, TPO serum conc. and TPO mRNA content. Gestational age ranged from 17 to 36 weeks. The amount of TPO mRNA were determined by RT / competitive PCR in samples from both liver lobes, kidney, spleen, and bone marrow. TPO levels were measured by ELISA. Considering the calculated total amount of TPO mRNA produced in liver, kidney, and spleen, expression in the liver accounted for 91 % (SD 12.8 %). No correlation between TPO mRNA expression and serum TPO concentration(median 131 pg/mL), platelet counts (median 112,000/µL), or gestational age was observed. Table

Table 1 Results: Expression of TPO mRNA (amol/µg total RNA)
Full size table

Conclusions: Liver, kidney, spleen and bone marrow of human fetuses express similar amounts of TPO mRNA/ug total RNA. The widest variation of TPO gene expression was observed in the liver. Quantitatively the liver seems to play the predominant role in total expression of TPO mRNA.