Liver engraftment and repopulation by in vitro expanded adult derived human liver stem cells in a child with ornithine carbamoyltransferase deficiency

A 3-year-old girl suffering from ornithine carbamoyltransferase (OTC) deficiency was poorly equilibrated under conventional diet and scavenger treatment. Following unsuccessful cryopreserved hepatocyte transplantation, she received two infusions of Adult Derived Human Liver Stem/Progenitor Cells (ADHLSCs) expanded in vitro under GMP settings, the quantity being equivalent to 0.75% of her calculated liver mass. Using FISH immunostaining for the Y chromosome, the initial biopsy did not detect any male nuclei in the recipient liver. Two liver biopsies taken 100 days after ADHLSC transplantation showed 3% and 5% of male donor cells in the recipient liver, thus suggesting repopulation by donor cells. Although limited follow-up did not allow us to draw conclusions on long-term improvement, these results provide a promising proof of concept that this therapy is feasible in an OTC patient.